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51,507,788 | https://en.wikipedia.org/wiki/Smart%20speaker | A smart speaker is a type of loudspeaker and voice command device with an integrated virtual assistant that offers interactive actions and hands-free activation with the help of one "hot word" (or several "hot words"). Some smart speakers can also act as a smart device that utilizes Wi-Fi and other protocol standards to extend usage beyond audio playback, such as to control home automation devices. This can include, but is not limited to, features such as compatibility across a number of services and platforms, peer-to-peer connection through mesh networking, virtual assistants, and others. Each can have its own designated interface and features in-house, usually launched or controlled via application or home automation software. Some smart speakers also include a screen to show the user a visual response.
As of summer 2022, it is estimated by NPR and Edison Research that 91 million Americans (35% of the population over 18) own a smart speaker.
A smart speaker with a touchscreen is known as a smart display. It is a smart device that integrates conversational user interface with display screens to augment voice interaction with images and video. They are powered by one of the common voice assistants and offer controls for smart home devices, feature streaming apps, and web browsers with touch controls for selecting content. The first smart displays were introduced in 2017 by Amazon (Amazon Echo) and Google (Google Home/Nest)
Accuracy
According to a study by Proceedings of the National Academy of Sciences of the United States of America released In March 2020, the six biggest tech development companies, Amazon, Apple, Google, Yandex, IBM and Microsoft, have misidentified more words spoken by "black people" than "white people". The systems tested errors and unreadability, with a 19 and 35 percent discrepancy for the former and a 2 and 20 percent discrepancy for the latter.
The North American Chapter of the Association for Computational Linguistics (NAACL) also identified a discrepancy between male and female voices. According to their research, Google's speech recognition software is 13 percent more accurate for men than women. It performs better than the systems used by Bing, AT&T, and IBM.
Privacy concerns
The built-in microphone in smart speakers is continuously listening for "hot words" followed by a command. However, these continuously listening microphones also raise privacy concerns among users. These include what is being recorded, how the data will be used, how it will be protected, and whether it will be used for invasive advertising. Furthermore, an analysis of Amazon Echo Dots showed that 30–38% of "spurious audio recordings were human conversations", suggesting that these devices capture audio other than strictly detection of the hot word.
As a wiretap
There are strong concerns that the ever-listening microphone of smart speakers presents a perfect candidate for wiretapping. In 2017, British security researcher Mark Barnes showed that pre-2017 Echos have exposed pins which allow for a compromised OS to be booted.
According to Umar Iqbal, an Assistant professor at Washington University in St. Louis, research indicates that data from consumer interactions with Alexa was used to targeted advertisements and products to consumer with over 40% of transmitted data lacking proper encryption raising privacy concerns. Furthermore data indicates that due to the Smart Speakers ability to always capture audio, it begins to pick up on external conversations from consumers not related to commands given to the smart speaker. Things such as other members in the household, consumers on the phone and even Tv audio can be picked up by these speakers and stored for future use by companies.
Voice assistance vs privacy
While voice assistants provide a valuable service, there can be some hesitation towards using them in various social contexts, such as in public or around other users. However, only more recently have users begun interacting with voice assistants through an interaction with smart speakers rather than an interaction with the phone. On the phone, most voice assistants have the option to be engaged by a physical button (e.g., Siri with a long press of the home button) rather than solely by hot word-based engagement in a smart speaker. While this distinction increases the privacy by limiting when the microphone is on, users felt that having to press a button first removed the convenience of voice interaction. This trade-off is not unique to voice assistants; as more and more devices come online, there is an increasing trade-off between convenience and privacy.
Factors influencing adoption
While there are many factors influencing smart speaker adoption, specifically with regards to privacy, Lau et al. define five distinct categories as pros and cons: convenience, identity as an early adopter, contributing factors, perceived lack of utility, privacy, and security concerns.
Smart speakers also benefit from their instant integration into the life of the consumer. Some capabilities of smart speakers are but not limited to setting alarms, sending voice messages to other smart devices in the home, the ability to send messages for you, instant answers to basic questions for any subject such as mathematics, geography, history, science and literature, and the ability to create task lists that can pair with your phone to remind you later on. Although these tasks can be completed by a phone, consumers tend to lean towards smart speakers due to factors such as their range being much greater then that of a phone and the need to not have to physically interact with the speaker to get the voice assistant as with most smartphones, certain parts of the phone must be interacted with to activate the speaking assistant.
Another reason for the adoption of smart speakers has been the use of smart speakers to help assist those with disabilities. While most technology is limited by it needs for the user to be able to physically interact with the device, smart speakers are not bound by these limitations and can serve as an excellent tool for those who are unable to use their arms or legs.
Security concerns
When configured without authentication, smart speakers can be activated by people other than the intended user or owner. For example, visitors to a home or office, or people in a publicly accessible area outside an open window, partial wall, or security fence, may be able to be heard by a speaker. One team demonstrated the ability to stimulate the microphones of smart speakers and smartphones through a closed window, from another building across the street, using a laser.
Most popular smart speaker devices and platforms
Gallery
See also
Smart home hub
Thread (network protocol)
Matter
References
Internet of things
Internet radio
Wireless
Applications of artificial intelligence | Smart speaker | [
"Technology",
"Engineering"
] | 1,307 | [
"Multimedia",
"Internet radio",
"Wireless",
"Telecommunications engineering"
] |
51,508,304 | https://en.wikipedia.org/wiki/Mytatrienediol | Mytatrienediol (developmental code name SC-6924; former tentative brand names Manvene, Anvene), also known as 16α-methyl-16β-epiestriol 3-methyl ether or 16β-hydroxy-16α-methylestradiol 3-methyl ether, is a synthetic steroidal estrogen medication and an estrogen ether which was derived from estriol and was developed for clinical use in the late 1950s but was never marketed. It was investigated as a weak and mildly estrogenic medication for men to treat atherosclerosis, improve serum lipid profiles, and reduce the risk of myocardial infarction. However, while preclinical research supported the profile of mytatriendiol as a weak estrogen, the medication was found in clinical trials to produce estrogenic side effects including feminization, breast pain, and gynecomastia in men similarly and comparably to other estrogens such as ethinylestradiol and conjugated estrogens, and its side effects ultimately precluded its use. The medication was also studied to treat bone pain in patients with multiple myeloma, metastatic bone disease, and osteoporosis, with effectiveness seen.
See also
List of estrogen esters § Ethers of steroidal estrogens
SC-4289
Triparanol
References
Abandoned drugs
Diols
Estranes
Estrogen ethers
Hypolipidemic agents
Synthetic estrogens | Mytatrienediol | [
"Chemistry"
] | 315 | [
"Drug safety",
"Abandoned drugs"
] |
51,508,407 | https://en.wikipedia.org/wiki/Pseudo-ring | In mathematics, and more specifically in abstract algebra, a pseudo-ring is one of the following variants of a ring:
A rng, i.e., a structure satisfying all the axioms of a ring except for the existence of a multiplicative identity.
A set R with two binary operations + and ⋅ such that is an abelian group with identity 0, and and for all a, b, c in R.
An abelian group equipped with a subgroup B and a multiplication making B a ring and A a B-module.
None of these definitions are equivalent, so it is best to avoid the term "pseudo-ring" or to clarify which meaning is intended.
See also
Semiring – an algebraic structure similar to a ring, but without the requirement that each element must have an additive inverse
References
Ring theory
Algebraic structures
Algebras | Pseudo-ring | [
"Mathematics"
] | 172 | [
"Algebra stubs",
"Mathematical structures",
"Algebras",
"Ring theory",
"Mathematical objects",
"Fields of abstract algebra",
"Algebraic structures",
"Algebra"
] |
71,531,998 | https://en.wikipedia.org/wiki/Mustakone | Mustakone is a tricylic sesquiterpenoid with the chemical formula C15H22O. It is named after the plant it was first extracted from Cyperus rotundus, which had the common name "mustuka" in Hindi. Mustakone can be found in a variety of plants and their oils like Myrcia sylvatica, Cyperus articulatus, and Hymenaea courbaril.
References
Tricyclic compounds
Ketones
Sesquiterpenes | Mustakone | [
"Chemistry"
] | 110 | [
"Ketones",
"Functional groups",
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
71,532,129 | https://en.wikipedia.org/wiki/Domitilla%20Del%20Vecchio | Domitilla Del Vecchio is an Italian control theorist, whose research connects control theory to systems biology, synthetic biology, synthetic biological circuits, and regenerative medicine. She has also studied self-organization in traffic control. She is a professor of mechanical engineering at the Massachusetts Institute of Technology (MIT) and a member of the MIT Synthetic Biology Center.
Education and career
Del Vecchio's father was a Roman engineer and her mother was a businesswoman. She earned a laurea at the University of Rome Tor Vergata in 1999, and completed a PhD in control theory and dynamical systems from the California Institute of Technology in 2005.
She became an assistant professor of electrical and engineering and computer science at the University of Michigan in 2006, also affiliated there with the Center for Computational Medicine and Bioinformatics. She moved to her present position at the Massachusetts Institute of Technology in 2010.
Book
Del Vecchio is coauthor of the book Biomolecular Feedback Systems (with Richard M. Murray, Princeton University Press, 2014).
Recognition
Del Vecchio was the 2010 winner of the Donald P. Eckman Award of the American Automatic Control Council, "for contributions to the theory and practice of hybrid dynamical systems and systems biology". She was named to the 2021 class of IEEE Fellows, "for contributions to circuit engineering in synthetic biology". She is also a Fellow of the International Federation of Automatic Control.
References
External links
Home page
Year of birth missing (living people)
Living people
Italian engineers
Italian women engineers
Control theorists
University of Rome Tor Vergata alumni
California Institute of Technology alumni
University of Michigan faculty
Massachusetts Institute of Technology faculty
Fellows of the IEEE
Fellows of the International Federation of Automatic Control | Domitilla Del Vecchio | [
"Engineering"
] | 349 | [
"Control engineering",
"Control theorists"
] |
71,534,202 | https://en.wikipedia.org/wiki/Longan%20wine | Longan wine is a Southeast Asian fermented drink made of the fruit of Dimocarpus longan, more commonly called longan or dark-skinned dragon's eye. While originating in China, it has also become a speciality in a number of locations in Southeast Asia such as the Vietnamese province of Bac Lieu.
History
The longan fruit has long been grown and produced as wine along the Great Wall of China and in the far west, especially in the provinces of Xinjiang, Gansu, Shanxi and Hebei. It gained popularity in the later half of the 20th century. Thus, the white wine of dried longan from China's Greatwall Wine Co. was a silver medal winner at the 14th International Wine-Tasting Meeting in London in 1983. Since then, production of longan wine has spread to Southeast Asia. Thus, since 2015, it has been developed commercially on a small-scale in Thailand and in Cambodia.
Preparation
Longan liqueur is made by macerating the longan flesh in alcohol.
In Southeast Asia, particularly in Northern Thailand, longan fruit is overabundant when in season and therefore it is dried and processed into various products, among which longan wine. This research was thus aimed to develop the high antioxidant wine from dried longan seed.
Fermentation temperature is suggested at 30°C due to the shorter time of production.
Health
Longan wine is much sweeter than other varieties and could therefore be discouraged in the case of diabetes. However, longan seed is a great source of Antioxidants and it is naturally extracted during fermentation. As a traditional drink, it is even recommended for men's health by Government of Bac Lieu province in Vietnam.
References
Fermented drinks
Tropical agriculture
Cambodian alcoholic drinks
Non-timber forest products
Drinking culture
Vietnamese alcoholic drinks | Longan wine | [
"Biology"
] | 376 | [
"Fermented drinks",
"Biotechnology products"
] |
71,535,495 | https://en.wikipedia.org/wiki/Kuratowski%27s%20intersection%20theorem | In mathematics, Kuratowski's intersection theorem is a result in general topology that gives a sufficient condition for a nested sequence of sets to have a non-empty intersection. Kuratowski's result is a generalisation of Cantor's intersection theorem. Whereas Cantor's result requires that the sets involved be compact, Kuratowski's result allows them to be non-compact, but insists that their non-compactness "tends to zero" in an appropriate sense. The theorem is named for the Polish mathematician Kazimierz Kuratowski, who proved it in 1930.
Statement of the theorem
Let (X, d) be a complete metric space. Given a subset A ⊆ X, its Kuratowski measure of non-compactness α(A) ≥ 0 is defined by
Note that, if A is itself compact, then α(A) = 0, since every cover of A by open balls of arbitrarily small diameter will have a finite subcover. The converse is also true: if α(A) = 0, then A must be precompact, and indeed compact if A is closed. Also, if A is a subset of B, then α(A) ≤ α(B). In some sense, the quantity α(A) is a numerical description of "how non-compact" the set A is.
Now consider a sequence of sets An ⊆ X, one for each natural number n. Kuratowski's intersection theorem asserts that if these sets are non-empty, closed, decreasingly nested (i.e. An+1 ⊆ An for each n), and α(An) → 0 as n → ∞, then their infinite intersection
is a non-empty compact set.
The result also holds if one works with the ball measure of non-compactness or the separation measure of non-compactness, since these three measures of non-compactness are mutually Lipschitz equivalent; if any one of them tends to zero as n → ∞, then so must the other two.
References
Compactness theorems | Kuratowski's intersection theorem | [
"Mathematics"
] | 428 | [
"Compactness theorems",
"Theorems in topology"
] |
71,535,582 | https://en.wikipedia.org/wiki/Gheorghe%20C%C4%83lug%C4%83reanu | Gheorghe Călugăreanu (16 June 1902 – 15 November 1976) was a Romanian mathematician, professor at Babeș-Bolyai University, and full member of the Romanian Academy.
He was born in Iași, the son of physician, naturalist, and physiologist Dimitrie Călugăreanu. From 1913 to 1921 he studied at the Gheorghe Lazăr High School in Bucharest, after which he attended University of Cluj, graduating in 1924. In 1926 he went to Paris to pursue his studies at the Sorbonne, supported by a scholarship from the Romanian government. He obtained his Ph.D. in mathematics in 1929, with thesis Sur les fonctions polygènes d'une variable complexe written under the direction of Émile Picard and defended before a jury that also included Édouard Goursat and Gaston Julia. After returning to Romania, he was appointed assistant the University of Cluj in 1930; he was promoted to lecturer in 1934 and named professor in 1942. From 1953 to 1957 he served as Dean of the Faculty of Mathematics. His Ph.D. students include Petru Mocanu. He was elected a corresponding member of the Romanian Academy in 1955, and he became a full member in 1963.
Călugăreanu studied the theory of functions of a complex variable (meromorphic functions, univalent functions, analytic extension invariants), as well as differential geometry and algebraic topology, especially in knot theory. In his best-known work, he established in 1961 the following foundational result regarding the writhe of a knot: take a ribbon in three-dimensional space, let be the linking number of its border components, and let be its total twist; then the difference depends only on the core curve of the ribbon. In a paper from 1959, he showed how to calculate the writhe of a knot by means of a Gaussian double integral. Călugăreanu's formula has since been pursued by James H. White and F. Brock Fuller, leading to applications in DNA topology, where writhe is used to describe the amount a piece of DNA is deformed as a result of torsional stress (a phenomenon known as DNA supercoiling). The topological interpretation of helicity in terms of the Gauss linking number and its limiting form has been called the "Călugăreanu invariant" by Keith Moffatt and Renzo L. Ricca.
He died of cancer in Cluj-Napoca in 1976; following his wishes, he was cremated and the urn was deposited at Bellu Cemetery in Bucharest.
Publications
References
External links
1902 births
1976 deaths
Scientists from Iași
Gheorghe Lazăr National College (Bucharest) alumni
Babeș-Bolyai University alumni
Academic staff of Babeș-Bolyai University
20th-century Romanian mathematicians
Complex analysts
Topologists
Titular members of the Romanian Academy
Deaths from cancer in Romania
Burials at Bellu Cemetery | Gheorghe Călugăreanu | [
"Mathematics"
] | 594 | [
"Topologists",
"Topology"
] |
71,535,589 | https://en.wikipedia.org/wiki/Selenosulfide | In chemistry, a selenosulfide refers to distinct classes of inorganic and organic compounds containing sulfur and selenium. The organic derivatives contain Se-S bonds, whereas the inorganic derivatives are more variable.
Organic selenosulfides
These species are classified as both organosulfur and organoselenium compounds. They are hybrids of organic disulfides and organic diselenides.
Preparation, structure, and reactivity
Selenosulfides have been prepared by the reaction of selenyl halides with thiols:
The equilibrium between diselenides and disulfides lies on the left:
RSeSeR + R'SSR' 2 RSeSR'
Because of the facility of this equilibrium, many of the best characterized examples of selenosulfides are cyclic, whereby S-Se bonds are stabilized intramolecularly. One example is the 1,8-selenosulfide of naphthalene. The selenium-sulfur bond length is about 220 picometers, the average of a typical S-S and Se-Se bond.
Occurrence
Selenosulfide groups can be found in almost all living organisms as part of various peroxidase enzymes, such as glutathione peroxidase and thioredoxin reductase. They are formed by the oxidative coupling of selenocysteine and cysteine residues. This reaction is powered by the decomposition of cellular peroxides, which can be highly damaging and a source of oxidative stress. Selenocysteine has a lower reduction potential than cysteine, making it very suitable for proteins that are involved in antioxidant activity.
Selenosulfides have been identified in some species of Allium and in roasted coffee. The mammalian version of the protein thioredoxin reductase contains a selenocysteine residue which forms a thioselenide (analogous to a disulfide) upon oxidation.
Inorganic selenosulfides
Some inorganic selenide sulfide compounds are also known. Simplest is the material selenium sulfide, which has medicinal properties. It adopt the diverse structures of elemental sulfur but with some S atoms replaced by Se.
Other inorganic selenide sulfide compounds occur as minerals and as pigments. One example is antimony selenosulfide.
The pigment cadmium red consists of cadmium sulfoselenide. It is a solid solution of cadmium sulfide, which is yellow, and cadmium selenide, which is dark brown. It is used as an artist's pigment. Unlike the organic selenosulfides and unlike selenide sulfide itself, no S-Se bond exists in CdS1−xSex or in Sb2S3−xSex.
References
Organoselenium compounds
Organosulfur compounds
Cadmium compounds
Selenides
Semiconductor materials
Optical materials
Mixed anion compounds
Sulfides | Selenosulfide | [
"Physics",
"Chemistry"
] | 610 | [
"Matter",
"Mixed anion compounds",
"Organosulfur compounds",
"Semiconductor materials",
"Organic compounds",
"Materials",
"Optical materials",
"Ions"
] |
71,539,197 | https://en.wikipedia.org/wiki/Odontoonychodermal%20dysplasia | Odontoonychodermal dysplasia is a rare genetic disorder which is characterized by systemic abnormalities of the teeth, the nails of the fingers and toes, the skin, the hair cells, and the sweat glands. It is a type of syndromic ectodermal dysplasia.
Signs and symptoms
Individuals with this condition typically have the following symptoms: complete absence of both the deciduous and permanent teeth, cone-shaped canines and incisors, generalized dysplasia of the nails, palmoplantar hyperkeratosis, chronic skin dryness, and variable degrees of both hypotrichosis and either hyperhidrosis or hypohidrosis.
Complications
The oligodontia associated with this condition results in both functional/mechanical and cosmetic problems.
Hyperhidrosis can increase one's susceptibility to infections and might cause problems with oneself's self esteem.
Hypohidrosis can result in a higher risk for suffering from heat-related illness, such as heat stroke.
Genetics
This condition is caused by homozygous mutations of the WNT10A gene, located in the second chromosome. These mutations are inherited in an autosomal recessive manner, which means that for a child to be born with the condition, they must inherit two copies of a mutation from both parents.
Diagnosis
This condition can be diagnosed through symptomatic examination and genetic testing.
Treatment
Treatment is focused on the symptoms
Epidemiology
According to OMIM, around 30 cases from families in Lebanon, Germany, Turkey, and India have been described in medical literature.
History
This condition was first discovered in 1983 by Fadhil et al. when they described 3 incestuous Muslim Shiite sibships from a family in Lebanon. Of the 24 children produced in these sibships, 7 were affected with what they (the researchers) a thought to be a novel ectodermal dysplasia syndrome, said children had nail dystrophy, peg-shaped incisors, erythematous facial lesions, hyperhidrotic palms and soles with thickened skin, dry sparse hair, and eyebrow thinning.
In 2007, Adaimy et al. found the molecular cause for this condition in affected members of 3 consanguineous Muslim Shiite families in Lebanon: they found a homozygous mutation in the WNT10A gene that was shared by all of the affected family members, said mutation resulted in a short, prematurely terminated protein of 232 amino acids instead of the usual amount of 417. Of the three families, two had been previously described in medical literature.
See also
Anonychia
Congenital onychodysplasia of the index fingers
References
Rare genetic syndromes
Autosomal recessive disorders
Histopathology
Genodermatoses
Syndromes affecting teeth
Syndromes affecting the skin | Odontoonychodermal dysplasia | [
"Chemistry"
] | 583 | [
"Histopathology",
"Microscopy"
] |
71,539,350 | https://en.wikipedia.org/wiki/Battarrea%20griffithsii | Battarrea griffithsii is a species of mushroom in the family Agaricaceae.
Taxonomy
Battarrea griffithsii was first described by V.S. White in a 1901 Bulletin of the Torrey Botanical Club.
References
External links
Mycobank General Information
Agaricaceae
Fungus species | Battarrea griffithsii | [
"Biology"
] | 60 | [
"Fungi",
"Fungus species"
] |
71,542,093 | https://en.wikipedia.org/wiki/Myrtenal | Myrtenal is a bicyclic monoterpenoid with the chemical formula C10H14O. It is a naturally occurring molecule that can be found in numerous plant species including Hyssopus officinalis, Salvia absconditiflora, and Cyperus articulatus.
Biological research
Myrtenal was shown to inhibit acetylcholinesterase, which is a common method of treatment of alzheimer's disease and dementia, in-vitro. In addition, mytenal has been shown to have antioxidant properties in rats.
See also
Myrtenol
References
Aldehydes
Bicyclic compounds
Cycloalkenes
Monoterpenes | Myrtenal | [
"Chemistry"
] | 146 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
71,542,798 | https://en.wikipedia.org/wiki/GG%20Carinae | GG Carinae is a binary star system in the southern constellation of Carina, abbreviated GG Car. It is a variable star with a brightness that fluctuates around an apparent visual magnitude of 8.67, making it too faint to be visible to the naked eye. The distance to this system is approximately 8,000 light years based on parallax measurements.
Observations
This star was found to have a peculiar spectrum by W. P. Fleming in 1892, matching the profile of a P Cygni star with bright emission lines of hydrogen. In 1930, the brightness of the star was found to be variable by W. E. Kruytbosch, who determined a period of and suggested it may be both an eclipsing binary and intrinsically variable. This period was confirmed by D. Hoffleit in 1933. A near infrared excess was detected in 1973, indicating a circumstellar dust shell.
Analysis of the spectrum by C. A. Hernández and associates in 1981 suggested the star is surrounded by a thick, extended envelope that is concealing absorption lines formed in the stellar photosphere. They used measurements of radial velocity variations to estimate a period of 31.03 days. In 1984, E. Gosset and associates used photoelectric photometry to find a period of 31.020 days, but were convinced by the data that the orbital period is twice that value, or 62.039 days. GG Carinae was classified as a supergiant B[e] star by Henny Lamers and associates in 1998, based on properties similar to B[e] supergiants in the Magellanic Clouds.
In 2004, M. A. Machado and associates used high resolution spectral measurements to confirm that this is a binary system with intrinsic variability. M. Kraus detected an enriched abundance of carbon-13 (in the form of 13CO) in the stellar wind, confirming that this is an evolved B[e] supergiant rather than a pre-main-sequence star. Kraus and associates in 2013 detected CO gas in a circumbinary ring, which was possibly placed there by the primary as a rapidly-spinning Be star. Alternatively, it may have come via Roche lobe overflow from the secondary member of the system, about which little is known. Brightness variations related to the orbital period are thought to be due to mass transfer between the components during periastron.
GG Carinae is almost certainly a member of the rich but faint open cluster ASCC 63, which is thought to have about 1,700 member stars. The cluster is calculated to be 18 million years old and away.
References
Further reading
B(e) stars
Binary stars
Circumstellar disks
Carina (constellation)
Durchmusterung objects
094878
053444
Carinae, GG | GG Carinae | [
"Astronomy"
] | 582 | [
"Carina (constellation)",
"Constellations"
] |
71,544,268 | https://en.wikipedia.org/wiki/Holmium%28III%29%20sulfide | Holmium(III) sulfide is the sulfide of holmium, with the chemical formula of . Like other rare earth sulfides, it is used as a high-performance inorganic pigment.
Preparation
Holmium(III) sulfide can be obtained by the reaction of holmium(III) oxide and hydrogen sulfide at 1325 °C.
Properties
Holmium(III) sulfide has orange-yellow crystals in the monoclinic crystal system, with the space group P21/m (No. 11). Under high pressure, holmium(III) sulfide can form in the cubic and orthorhombic crystal systems.
References
Holmium compounds
Sesquisulfides | Holmium(III) sulfide | [
"Chemistry"
] | 142 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
64,260,917 | https://en.wikipedia.org/wiki/Cornelius%20Atherton | Cornelius Atherton (1737–1809), was an iron manufacturer, an inventor and an active gunmaker for patriot cause during the American Revolutionary War.
He became closely involved in the first large scale production of "American Steel".
He and his eldest son, John Daniel are recognized as the founders of borough of Taylor, Pennsylvania.
Early life
He was the son of John Atherton (1709-1755) of Harvard, Massachusetts. His paternal great-grandfather was James Atherton (1654-1718) of Lancaster, Massachusetts. His great-great-grandfather James Atherton, emigrated to America, and was one of the founders of Lancaster, Massachusetts.
Various obituaries claim that he is the fourth in descent from Major Gen. Humphrey Atherton of Boston. A further discrepancy in relation to his birthplace by late 19th biographers, was carried over to a submission to the Daughters of the American Revolution during the 20th century. His birthplace was incorrectly stated as Cambridge, Massachusetts. However, with the ease of access to birth and church records that has been proven to be incorrect. Confusion is likely to have arisen due to his close association with both Boston and Cambridge, Massachusetts, through his tradecraft; or that his birthplace of Harvard, Massachusetts was confused with Harvard University in Cambridge, Massachusetts.
His birthdate has also been misquoted as February 5, 1736, instead of May 1737. A number of sources refer to his mother being Mary Sawyer (born Sep 11, 1714); the daughter of James Cornet Sawyer and Mary Prescott. Mary Sawyer did marry a John Atherton on May 25, 1735, in Pomfret, CT. However that is not conclusive proof of a parental link. The Sawyers were however accomplished blacksmiths in at his place of birth and he did carry out that trade. Some researchers have named Phebe Harris (1713-1795) as his mother. What is almost certain is that he was the son of John Atherton and was baptized in Harvard, Massachusetts on May 8, 1737. His maternal line is unproven.
Career
Atherton was a blacksmith by trade and was the first to forge steel in Colonial America. As a resourceful blacksmith, he made the first pair of clothier sheers in America and was also a gun maker at a time when most pistols were imported from England. He also discovered the process of converting iron into ‘American steel’.
In 1763 he relocated to Amenia, NY. Atherton entered into a contract with two merchant brothers, James and Ezra Reed, to superintend the erection of steel works in Amenia, and to instruct their workmen in the art of making steel. The steelworks were erected at Dover Iron Works in Amenia. It became a successful operation, and a decade later, during the American Revolutionary War it supplied muskets for the Continental Army.
Atherton relocated temporarily to Cambridge, Massachusetts, in 1769, after entering into a partnership with Samuel Adams, John Adams and John Hancock. He superintended an existing armory and commenced the manufacture of cutlery and firearms. 6 months later it was burned down by an incendiary, likely to have been placed by British troops who were quartered in Boston, since the colonial authorities suspected their patriotic intentions arming the local population during the time of the Boston Massacre. Hancock's signature would later become the most prominent on the United States Declaration of Independence.
During 1770, Atherton returned to Amenia, Province of New York, and announced in the local paper that he would now be serving the
Great Nine Partners Patent area with the manufacture and repair of clothier sheers. Atherton settled in Plymouth, Pennsylvania, in 1773 with his family, where he made farm tools and bells.
He went to Florida, Orange County, New York, in the summer of 1773 and remained there during the war and remained there until 1783. As a patriot, Atherton played a role in preparing for the siege of New York during the New York and New Jersey campaign. Atherton as a gunsmith, concluded an agreement with Agreement with Alexander McDougall and Peter T. Curtenius of the City of New York, acting with authority of the New York Provincial Congress during November 1775. During September the following year, he petitioned the provincial congress for an exemption from military duty for his workmen, whilst they engaged in the manufacture of firearms under Atherton's contract with the provincial congress at the Dover Steel Works. Shortly after he relocated with his family to Plymouth, Pennsylvania.
In 1778 Atherton was drafted, however his place was filled by his eldest son, Jabez, who volunteered to become his substitute, and was accepted and mustered in as a private. This allowed Atherton to care for his wife Mary, who was infirm. His son, Jabez was killed in the Battle of Wyoming on July 3, 1778, and is listed on the Wyoming Monument. The aftermath of the battle meant that Atherton and his family had to leave the area for their safety.
Cornelius Atherton & the treason of Benedict Arnold (1780)
On September 21, 1780, during the American Revolution, American General Benedict Arnold met with British Major John Andre to discuss handing over Fort Clinton, now known as West Point, New York, to the British, in return for the promise of a large sum of money and a high position in the British army. The plot was foiled and Arnold, a former American hero, became synonymous with the word “traitor.”
His son Cornelius Jr recounted the incident:“I was informed by my mother years ago, when I was a young man, that on his learning the British ship Vulture was anchored in the river below West Point, my father Cornelius Atherton, with another man (name forgotten) went to a Colonel Livingston, in command of a small battery , five or six miles below West Point, asking him to send a small detachment up on the Heights, and drive the Vulture away, but the Colonel dare not weaken his small force. He finally gave them a twelve pound carronade and two gunners, with ammunition a plenty. In a short time they had their gun in position on the highland banks, within easy range of the Vulture and perfectly safe from her guns. After trying a cold short a few times without effect they improvised a furnace and made the balls red hot, and at the first fire struck a red hot ball in the deck of the vessel. A second and third were equally successful. She cast her cable and took her way down river, out of the way of the guns on the heights. This I believe to be a true statement of the cause of Major Andre’s capture, and saving West Point from falling into the hands of the British. Cornelius Atherton”
Colonel James Livingston of the 1st Canadian Regiment was in command of Verplanck's Point on the Hudson River in September 1780, and played a crucial role in the unmasking of Benedict Arnold's treachery. While on guard duty, his troops fired on the British sloop of war HMS Vulture, forcing it to retreat southwards. This ship had brought Major John André to meet with General Benedict Arnold, who was then in command at West Point, New York. Since the ship was driven off, André was forced to attempt travel by land onto the city of New York, when he was captured not far from the British lines near Tarrytown, NY. André mistook patriots for loyalists, and was caught with incriminating papers upon his possession and was tried and hanged as a spy, and Arnold, his plot now discovered, fled to the British lines. Such events occurred due to the efforts of Atherton, as an astute minuteman who proposed moving a suitable cannon to fire upon HMS Vulture.
Later years
He moved to Keyser Creek in 1782 and lived on a hill overlooking it. The area today is known as Taylor, Pennsylvania. The area today is known as Taylor, Pennsylvania.
He relocated one final time, returning to Afton, New York, in 1803, where he traded until his death 6 years later.
Personal
He married Margaret “Mary” Delano (b. June 4, 1744); the daughter of Jonathan and Mary Delano in Dartmouth, Massachusetts, in 1760. Some sources incorrectly state that his first wife was from Tolland, CT. Their firstborn son was Jabez. They had 8 further children together.
Atherton chose to relocate numerous times, since his skills were in demand, relocating with his young family to Amenia, NY in 1763. However his uncle, James Atherton had moved further west, to what is now known as Wyoming, Pennsylvania. His uncle was one of the first settlers to arrive from Connecticut, and was likely to have been either a cousin or uncle. Some sources have incorrectly referred to James as being Atherton's father.
His sisters married his future business partners. His nephew was Cornelius Allerton.
He was widowed in 1786. Some sources incorrectly state that his first wife died in 1774. However she was alive when their oldest son Jebez was killed in the 1778, albeit very sickly. Atherton married Jane Johnson (1767-1848) during 1786. They had 7 children together.
He relocated to South Bainbridge, now known as Afton, New York, in 1803 with his second wife and young children.
He died on December 4, 1809, aged 73. He was buried at Vallonia Springs Cemetery in Colesville, New York. His wife Jane died on August 13, 1848, and was buried in the same cemetery, which is located in an isolated field.
Descendants
From his first marriage:
Jebez Atherton (1761-1778) born in NY. He was a Private in the Revolutionary War and was killed in the Battle of Wyoming, also known as the Wyoming Massacre, aged 16.
John Daniel Atherton (1762-1841/ or 1845), married Mary Fulkerson of Six Mile Run, New Jersey. He had 12 children.
Eleazer Augustus Atherton, Sr., born December 1764 in NY; married Martha Kinna of New Jersey. He had 7 children. He died March 3, 1852, in Taylor, PA.
Elisha Atherton, born c. 1765. He married Martha Delaney.
Mary (Polly) Atherton, born c. 1765 in PA; died c. 1829.
Parthenia Atherton, born Bet. 1765 - 1771; died September 24, 1845.
Prudence Atherton, born 1772. She married Raynesford Hoyt.
and 2 others that did not reach adulthood.
From his second marriage:
Humphrey Atherton (1787-1849). Born in Luzerne, Pennsylvania, on July 20, 1787; he was a miller. He married and died without issue in Afton, NY on December 11, 1849, aged 62.
Angelina Atherton Church (1791-1847). Born Jan 27th, 1791; died July 15, 1847. She married Col. Ira Church.
Charles Atherton (1793-1869). Born in Luzerne on May 23, 1783. He was a blacksmith. He married Experience Bramhall, and relocated to Friendship, Allegany Co., where he worked at his trade several years, till the death of his wife, when he sold his property and went with a friend to Emporium, PA, where he died May 13, 1869, aged 76 without issue.
Hiram Atherton (1796-1870). Born in Luzerne on Jun 16, 1796. He married Lovina Sisson, of Plymouth, and followed his trade of wagon-maker a few years in Afton, NY and subsequently for several years in Norwich, from whence he removed to Greene, and engaged in the cabinet business, which he pursued till his death, March 19, 1870, aged 73. They had five children.
Christina Atherton Clapper (1799-1842). Born Jan 8, 1799; died January 24, 1842.
William J. Atherton (1802-1879). Born May 25, 1802; died August 2, 1879, in Paterson, NJ. He was a shoemaker. He married Jane E. Hamlin and had two children, both of whom died in infancy. They relocated to Paterson, NJ, where he died on August 2, 1879, aged 77.
Cornelius Atherton Jnr (1805-1881). Born in New York on December 7, 1805. He lived in Afton and died October 10, 1881. He was appointed as the first postmaster of Afton, New York in 1855. He was present at the Centenary of the Wyoming Massacre. He had one son, William Monroe Atherton (1855-1905) who was a telegraph operator on the Baltimore & Ohio R. R, and who died in Chicago but was buried in Indiana.
See also
Iron Act
History of the iron and steel industry in the United States
Biography
Kemnitz, Katherine Three John Chamberlains and Cornelius Atherton
Oscar Jewel Harvey, The History of Wilkes-Barre and Wyoming Valley
Smith, James H., History of Chenango and Madison Counties, New York . Published by D. Mason & Co. Syracuse, NY (1880)
External links
Wyoming Valley Historical Society
Lucerne County Historical Society
Wyoming Valley History
Wilkes-Barre History
The story of Afton, NY
Photos of the gravestone of Cornelius Atherton - Find A Grave...
References
1809 deaths
Patriots in the American Revolution
18th-century American inventors
People from Afton, New York
People from Lancaster, Massachusetts
People from Luzerne County, Pennsylvania
Steelmaking
1737 births
Gunsmiths
Firearm designers
Inventors from Massachusetts | Cornelius Atherton | [
"Chemistry"
] | 2,753 | [
"Metallurgical processes",
"Steelmaking"
] |
64,262,637 | https://en.wikipedia.org/wiki/Sikta%20Irrigation%20Project | Sikta Irrigation Project is one of the National Pride Projects of Nepal. The intake is in the Rapti river in western Nepal. There are two canals with the capacity of 50 m3/s each. The length of canal is 45.25 kilometres in the western section and 53 kilometres in the eastern section. The canals are constituted into 3 phases. As of 2019, 60% of the project has been completed.
Project Development
The feasibility study of the project was done by Lahmeyer International GmbH from Germany in 1980. In 1983, the Department of Hydrology and Metrology revised the study. In 2004, the Irrigation Development Programme under the European Union concluded that the project is feasible which led the government to start the project by its own resources.
The initial project cost in 2005-06 was NPR 12.8 billion and estimated to be completed by 2014–15. The project is still under construction and is estimated to be complete by 2020. The project is expected to rise to NPR 25.02 billion. In 2019, the project completion was 60%.
The contractor for construction is CTC Kalika Joint Venture Pvt Ltd. The project targets to irrigate 42,000 hectares of land in Banke District.
Damages and Accidents
In 2016, a canal section collapsed due to weak soil properties during testing at the flow of 5m³/s.
In September 2017, damages were reported in multiple section of the canal. The damage was due to cross-drainage problem in the canal. Most of the damage were found near the siphon areas.
In 2018, damages in canal were reported during testing.
Corruption
The national Commission for Investigation of Abuse of Authority (CIAA) has lodged a corruption case of over NPR 2 billion in this project. The case was filed against former minister and chief of Kalika Construction Bikram Pandey over the construction of a canal and 20 other staffs. CIAA has made claims of Rs 2.13 billion from Bikram Pandey, NPR 1.56 billion from Dilip Bahadur Karki and NPR 593.45 million from Saroj Chandra Pandit. It also claims Rs 24.05 million from Uddhav Raj Chaulagai, the managing director of the consulting company (ERMC).
See also
Department of Water Resources and Irrigation
References
Irrigation projects
Agriculture in Nepal
Canals in Nepal
National Pride Projects
Buildings and structures in Banke District | Sikta Irrigation Project | [
"Engineering"
] | 482 | [
"Irrigation projects"
] |
64,263,166 | https://en.wikipedia.org/wiki/Pantometrum%20Kircherianum | Pantometrum Kircherianum is a 1660 work by the Jesuit scholars Gaspar Schott and Athanasius Kircher. It was dedicated to Christian Louis I, Duke of Mecklenburg and printed in Würzburg by Johann Gottfried Schönwetter. It was a description, with building instructions, of a measuring device called the pantometer, that Kircher had developed some years before. The first edition include 32 copperplate illustrations.
Description of the pantometer
The name "pantometer" derives from Greek, in which "pan" means "all" and "metron" means "measure" - indicating that this instrument can be used to measure anything. As described in the book, it consisted of a square frame, a dioptra, and a disc that fitted within the square. The disc contained a built-in compass and a space for putting a sheet of paper. The disc could turn freely within the square, or be locked in a fixed position. Mounted on this apparatus was a movable ruler parallel to the edge of the square on which the dioptra was attached. An illustration in the book showed how the device could be used to measure the distance of objects by triangulating from two different points on a baseline.
The introduction to the book emphasised both the accuracy of the device and its ease of use, and stated that it could be used to "measure all, witness latitudes, longitudes, altitudes, depths and surfaces, terrestrial and celestial bodies, and whatever indeed we are accustomed to doing with other instruments."
Kircher's development of the pantometer
Kircher had mentioned the pantometer in his Specula Melitensis Encyclica noting that it was designed to help the Knights Hospitaller to solve "the most important mathematical and physical problems." It was a surveying tool that resembled a draughts board and could be used to calculate distances, weights and dimensions. In Magnes sive de Arte Magnetica (1643) Kircher has described an "Instrumentum, Pantometrum, Ichnographicum Magneticum" which allowed all things to be measured. It was 'magnetic' because it incorporated a compass, and 'ichnographic' because it could be used in map-making.
According to Schott, Kircher had first conceived of it in the company of father Ziegler, perhaps as early as 1623. Schott has been with Kircher in 1631 when he had first assembled the instrument and named it the 'pantometrum', sending an early example to Holy Roman Emperor Frederick III. Kircher had certainly used the pantometer himself to take scientific measurements when he was lowered into the crater of Vesuvius in 1638.
Later editions and references
Pantometrum Kircherianum was reprinted by Cholinus in Frankfurt in 1668 and again in 1669. The work was referenced in books by a number of later writers, including Jacob Leupold's Theatrum Arithmetico-Geometricum (1727) and Christian Wolff's Mathematisches Lexikon (1747).
External links
digital copy of Pantometrum Kircherianum at the Max Planck Institute Library
digital copy of Pantometrum Kircherianum at the Bayerische Staatsbibliothek
See also
Graphometer
References
1660 in science
1660 in the Holy Roman Empire
1660 books
Dimensional instruments
Athanasius Kircher | Pantometrum Kircherianum | [
"Physics",
"Mathematics"
] | 704 | [
"Quantity",
"Dimensional instruments",
"Physical quantities",
"Size"
] |
64,265,395 | https://en.wikipedia.org/wiki/Architectural%20ensemble | The architectural ensemble (from the - integrity, connectedness, unity) is harmonious unity of the spatial composition of buildings, engineering structures (bridges, embankments, etc.), works of monumental painting, sculpture and landscape gardening art. The image of the architectural ensemble depends on the change of lighting, season, the presence of people. An important element of the ensemble can serve as a landscape. In this case, the topography (for example, churches that were built on the high bank of the river) can play a key role. Very often, architectural ensembles include ponds.
There are architectural ensembles created at a time, according to a single plan, and ensembles that take shape over the years, the efforts of many architects, carefully complementing the emerging composition so that new elements are organically combined with old ones. Classical examples of such ensembles include St. Mark's Square in Venice and Palace Square in St. Petersburg.
Literature
Bundesministerium für Unterricht, Kunst und Kultur (BMUKK), Bundesdenkmalamt (BDA): Standards Für Ensemble-Unterschutzstellungen. BMUKK-GZ 13.600/0030-IV/3/2013, Stand: 19. November 2013 – erarbeitet im Rahmen eines mehrphasigen Pilotprojektes zum Thema UNESCO-Welterbe – Ensembleschutz, Neue Wege der Zusammenarbeit zum Nutzen der Bürgerinnen und Bürger (, bda.at; betrifft Österreich).
Urban planning
Architecture | Architectural ensemble | [
"Engineering"
] | 334 | [
"Construction",
"Urban planning",
"Architecture stubs",
"Architecture"
] |
64,266,300 | https://en.wikipedia.org/wiki/Schwartz%20topological%20vector%20space | In functional analysis and related areas of mathematics, Schwartz spaces are topological vector spaces (TVS) whose neighborhoods of the origin have a property similar to the definition of totally bounded subsets. These spaces were introduced by Alexander Grothendieck.
Definition
A Hausdorff locally convex space with continuous dual , is called a Schwartz space if it satisfies any of the following equivalent conditions:
For every closed convex balanced neighborhood of the origin in , there exists a neighborhood of in such that for all real , can be covered by finitely many translates of .
Every bounded subset of is totally bounded and for every closed convex balanced neighborhood of the origin in , there exists a neighborhood of in such that for all real , there exists a bounded subset of such that .
Properties
Every quasi-complete Schwartz space is a semi-Montel space.
Every Fréchet Schwartz space is a Montel space.
The strong dual space of a complete Schwartz space is an ultrabornological space.
Examples and sufficient conditions
Vector subspace of Schwartz spaces are Schwartz spaces.
The quotient of a Schwartz space by a closed vector subspace is again a Schwartz space.
The Cartesian product of any family of Schwartz spaces is again a Schwartz space.
The weak topology induced on a vector space by a family of linear maps valued in Schwartz spaces is a Schwartz space if the weak topology is Hausdorff.
The locally convex strict inductive limit of any countable sequence of Schwartz spaces (with each space TVS-embedded in the next space) is again a Schwartz space.
Counter-examples
Every infinite-dimensional normed space is not a Schwartz space.
There exist Fréchet spaces that are not Schwartz spaces and there exist Schwartz spaces that are not Montel spaces.
See also
References
Bibliography
Functional analysis
Topological vector spaces | Schwartz topological vector space | [
"Mathematics"
] | 360 | [
"Functions and mappings",
"Functional analysis",
"Vector spaces",
"Mathematical objects",
"Topological vector spaces",
"Space (mathematics)",
"Mathematical relations"
] |
64,266,563 | https://en.wikipedia.org/wiki/Cholesterol%20signaling | Cholesterol is a cell signaling molecule that is highly regulated in eukaryotic cell membranes. In human health, its effects are most notable in inflammation, metabolic syndrome, and neurodegeneration. At the molecular level, cholesterol primarily signals by regulating clustering of saturated lipids and proteins that depend on spatial biology and clustering for their regulation.
Mechanism
Lipid rafts are loosely defined as clusters of cholesterol and saturated lipids forming regions of lipid heterogeneity in cellular membranes (e.g., the ganglioside GM1). The association of proteins to lipid rafts is cholesterol dependent and regulates the proteins' function (e.g., substrate presentation).
Lipid raft regulation
Cholesterol regulates the function of several membrane proteins associated with lipid rafts. It does so by controlling the formation or depletion of lipid rafts in the plasma membrane. The lipid rafts house the membrane proteins and forming or depleting the lipid rafts moves the proteins in or out of the raft environment, thereby exposing them to a new environment that can activate or deactivate the proteins. For example, cholesterol directly regulates the affinity of palmitoylated proteins for GM1 containing lipid rafts. Cholesterol signaling through lipid rafts can be attenuated by phosphatidylinositol 4,5 bisphosphate signaling (PIP2). PIP2 contains mostly polyunsaturated lipids that partition away from saturated lipids. Proteins that bind both lipid rafts and PIP2 are negatively regulated by high levels of PIP2. This effect was observed with phospholipase D.
In the brain, astrocytes make the cholesterol and transport it to nerves to control their function. In this sense, cholesterol functions as a hormone.
Substrate presentation
A protein subject to regulation through raft-associated translocation can undergo activation upon substrate presentation. For instance, an enzyme that translocates within the membrane towards its substrate can be activated by localizing to the substrate, irrespective of any conformational changes in the enzyme itself.
Protein ligand
In addition to lipid rafts, cholesterol can also interact with proteins that possess lipid-binding domains, such as certain types of sterol-sensing domains or cholesterol recognition/interaction amino acid consensus (CRAC) motifs. These interactions can affect protein conformation, stability, and function, thereby influencing various cellular processes like signal transduction, membrane trafficking, and enzyme activity. As a signaling lipid, cholesterol may act as a ligand.
Ion channels
Numerous ion channels undergo palmitoylation, a process where a lipid is covalently linked to a protein. Moreover, a significant subset of ion channels demonstrate a direct affinity for cholesterol binding. The regulation of ion channels by cholesterol can stem from both direct binding interactions and an indirect influence, facilitated by the localization of palmitoylated residues within lipid rafts. It's important to note that these two mechanisms are not mutually exclusive; they can concurrently contribute to the modulation of ion channel activity and localization.
The spatial arrangement of an ion channel can profoundly impact its activation potential. Proposed mechanisms for this phenomenon encompass alterations in membrane thickness and the concentration of lipid molecules critical for signaling. One instance of this is observed in TREK-1 channels, which transition between lipid rafts and PIP2 domains, where they interact with an activating lipid. Similarly, Kir2.1 channels experience inhibition due to cholesterol while being activated by PIP2. Consequently, a transition from cholesterol-enriched GM1 to PIP2-rich domains is anticipated to trigger channel activation. Conversely, the scenario is opposite for nAChR, which responds positively to cholesterol, eliciting its activation.
Role in Disease
Alzheimer's Disease
In the brain, cholesterol is synthesized in astrocytes and transported to neurons with the cholesterol transport protein apolipoprotein E (apoE). The cholesterol controls the clustering of amyloid precursor protein with gamma secretase in GM1 lipid domains. High cholesterol induces APP hydrolysis and the eventual accumulation of amyloid plaques tau phosphorylation. The ApoE isotype4 is the greatest risk factor for sporadic Alzheimer's and this allele was shown to increase cholesterol in mice.
Inflammation
Cholesterol uptake by cells instigates inflammation, affecting both the central nervous system and the peripheral systems. This phenomenon involves the aggregation of inflammatory proteins. For instance, in the context of TLR4, cholesterol prompts receptor dimerization. Similarly, with TNF alpha, the substrate facilitates the enzyme's binding. Subsequent hydrolysis yields soluble cytokines, contributing to the inflammatory response.
During an inflammatory response cholesterol is loaded into immune cells including macrophages. The cholesterol is a signal that activates cytokine production and other inflammatory responses. Cholesterol's role in inflammation is central to many diseases.
Viral entry
Numerous viruses exploit lipid rafts and endocytosis as entry pathways. Notably, SARS-CoV-2 has been demonstrated to leverage heightened cholesterol levels stemming from an immune response, thereby amplifying endocytosis and infectivity. Moreover, tissue cholesterol levels tend to rise with age. This augmented cholesterol presence provides insight into the greater severity of COVID-19 in elderly and chronically ill patients.
Coronary Heart Disease
inflammation induced by cholesterol loading into immune cells causes heart disease. A class of drugs called statins blocks cholesterol synthesis and is used extensively in treating heart disease.
Steroids
Cholesterol is precursor for steroid hormones including progestogens, glucocorticoids, mineralocorticoids, androgens, and estrogens.
History
Brown and Goldstein discovered the LDL receptor and showed cholesterol is loaded into cells through receptor mediated endocytosis. Until recently cholesterol was thought of primarily as a structural component of the membrane. However, more recently, cholesterol uptake was shown to signal an immune response in macrophages. More importantly, the ability to efflux cholesterol through ABC transporters was shown to attenuate (i.e., shut down) the inflammatory response.
References
Biochemistry
Cholestanes | Cholesterol signaling | [
"Chemistry",
"Biology"
] | 1,332 | [
"Biochemistry",
"nan"
] |
64,266,856 | https://en.wikipedia.org/wiki/Distinguished%20space | In functional analysis and related areas of mathematics, distinguished spaces are topological vector spaces (TVSs) having the property that weak-* bounded subsets of their biduals (that is, the strong dual space of their strong dual space) are contained in the weak-* closure of some bounded subset of the bidual.
Definition
Suppose that is a locally convex space and let and denote the strong dual of (that is, the continuous dual space of endowed with the strong dual topology).
Let denote the continuous dual space of and let denote the strong dual of
Let denote endowed with the weak-* topology induced by where this topology is denoted by (that is, the topology of pointwise convergence on ).
We say that a subset of is -bounded if it is a bounded subset of and we call the closure of in the TVS the -closure of .
If is a subset of then the polar of is
A Hausdorff locally convex space is called a distinguished space if it satisfies any of the following equivalent conditions:
If is a -bounded subset of then there exists a bounded subset of whose -closure contains .
If is a -bounded subset of then there exists a bounded subset of such that is contained in which is the polar (relative to the duality ) of
The strong dual of is a barrelled space.
If in addition is a metrizable locally convex topological vector space then this list may be extended to include:
(Grothendieck) The strong dual of is a bornological space.
Sufficient conditions
All normed spaces and semi-reflexive spaces are distinguished spaces.
LF spaces are distinguished spaces.
The strong dual space of a Fréchet space is distinguished if and only if is quasibarrelled.
Properties
Every locally convex distinguished space is an H-space.
Examples
There exist distinguished Banach spaces spaces that are not semi-reflexive.
The strong dual of a distinguished Banach space is not necessarily separable; is such a space.
The strong dual space of a distinguished Fréchet space is not necessarily metrizable.
There exists a distinguished semi-reflexive non-reflexive -quasibarrelled Mackey space whose strong dual is a non-reflexive Banach space.
There exist H-spaces that are not distinguished spaces.
Fréchet Montel spaces are distinguished spaces.
See also
References
Bibliography
Topological vector spaces | Distinguished space | [
"Mathematics"
] | 480 | [
"Topological vector spaces",
"Vector spaces",
"Space (mathematics)"
] |
64,267,369 | https://en.wikipedia.org/wiki/Countably%20barrelled%20space | In functional analysis, a topological vector space (TVS) is said to be countably barrelled if every weakly bounded countable union of equicontinuous subsets of its continuous dual space is again equicontinuous.
This property is a generalization of barrelled spaces.
Definition
A TVS X with continuous dual space is said to be countably barrelled if is a weak-* bounded subset of that is equal to a countable union of equicontinuous subsets of , then is itself equicontinuous.
A Hausdorff locally convex TVS is countably barrelled if and only if each barrel in X that is equal to the countable intersection of closed convex balanced neighborhoods of 0 is itself a neighborhood of 0.
σ-barrelled space
A TVS with continuous dual space is said to be σ-barrelled if every weak-* bounded (countable) sequence in is equicontinuous.
Sequentially barrelled space
A TVS with continuous dual space is said to be sequentially barrelled if every weak-* convergent sequence in is equicontinuous.
Properties
Every countably barrelled space is a countably quasibarrelled space, a σ-barrelled space, a σ-quasi-barrelled space, and a sequentially barrelled space.
An H-space is a TVS whose strong dual space is countably barrelled.
Every countably barrelled space is a σ-barrelled space and every σ-barrelled space is sequentially barrelled.
Every σ-barrelled space is a σ-quasi-barrelled space.
A locally convex quasi-barrelled space that is also a 𝜎-barrelled space is a barrelled space.
Examples and sufficient conditions
Every barrelled space is countably barrelled.
However, there exist semi-reflexive countably barrelled spaces that are not barrelled.
The strong dual of a distinguished space and of a metrizable locally convex space is countably barrelled.
Counter-examples
There exist σ-barrelled spaces that are not countably barrelled.
There exist normed DF-spaces that are not countably barrelled.
There exists a quasi-barrelled space that is not a 𝜎-barrelled space.
There exist σ-barrelled spaces that are not Mackey spaces.
There exist σ-barrelled spaces that are not countably quasi-barrelled spaces and thus not countably barrelled.
There exist sequentially barrelled spaces that are not σ-quasi-barrelled.
There exist quasi-complete locally convex TVSs that are not sequentially barrelled.
See also
Barrelled space
H-space
Quasibarrelled space
References
Functional analysis | Countably barrelled space | [
"Mathematics"
] | 552 | [
"Functional analysis",
"Mathematical objects",
"Functions and mappings",
"Mathematical relations"
] |
64,267,601 | https://en.wikipedia.org/wiki/Buchdahl%27s%20theorem | In general relativity, Buchdahl's theorem, named after Hans Adolf Buchdahl, makes more precise the notion that there is a maximal sustainable density for ordinary gravitating matter. It gives an inequality between the mass and radius that must be satisfied for static, spherically symmetric matter configurations under certain conditions. In particular, for areal radius , the mass must satisfy
where is the gravitational constant and is the speed of light. This inequality is often referred to as Buchdahl's bound. The bound has historically also been called Schwarzschild's limit as it was first noted by Karl Schwarzschild to exist in the special case of a constant density fluid. However, this terminology should not be confused with the Schwarzschild radius which is notably smaller than the radius at the Buchdahl bound.
Theorem
Given a static, spherically symmetric solution to the Einstein equations (without cosmological constant) with matter confined to areal radius that behaves as a perfect fluid with a density that does not increase outwards. (An areal radius corresponds to a sphere of surface area . In curved spacetime the proper radius of such a sphere is not necessarily .) Assumes in addition that the density and pressure cannot be negative. The mass of this solution must satisfy
For his proof of the theorem, Buchdahl uses the Tolman-Oppenheimer-Volkoff (TOV) equation.
Significance
The Buchdahl theorem is useful when looking for alternatives to black holes. Such attempts are often inspired by the information paradox; a way to explain (part of) the dark matter; or to criticize that observations of black holes are based on excluding known astrophysical alternatives (such as neutron stars) rather than direct evidence. However, to provide a viable alternative it is sometimes needed that the object should be extremely compact and in particular violate the Buchdahl inequality. This implies that one of the assumptions of Buchdahl's theorem must be invalid. A classification scheme can be made based on which assumptions are violated.
Special Cases
Incompressible fluid
The special case of the incompressible fluid or constant density, for , is a historically important example as, in 1916, Schwarzschild noted for the first time that the mass could not exceed the value for a given radius or the central pressure would become infinite. It is also a particularly tractable example. Within the star one finds.
and using the TOV-equation
such that the central pressure, , diverges as .
Extensions
Extensions to Buchdahl's theorem generally either relax assumptions on the matter or on the symmetry of the problem. For instance, by introducing anisotropic matter or rotation. In addition one can also consider analogues of Buchdahl's theorem in other theories of gravity
References
Mathematical theorems
1959 in science
Energy (physics) | Buchdahl's theorem | [
"Physics",
"Mathematics"
] | 587 | [
"Mathematical theorems",
"Physical quantities",
"Quantity",
"Energy (physics)",
"nan",
"Wikipedia categories named after physical quantities",
"Mathematical problems"
] |
64,267,682 | https://en.wikipedia.org/wiki/Bornivorous%20set | In functional analysis, a subset of a real or complex vector space that has an associated vector bornology is called bornivorous and a bornivore if it absorbs every element of
If is a topological vector space (TVS) then a subset of is bornivorous if it is bornivorous with respect to the von-Neumann bornology of .
Bornivorous sets play an important role in the definitions of many classes of topological vector spaces, particularly bornological spaces.
Definitions
If is a TVS then a subset of is called and a if absorbs every bounded subset of
An absorbing disk in a locally convex space is bornivorous if and only if its Minkowski functional is locally bounded (i.e. maps bounded sets to bounded sets).
Infrabornivorous sets and infrabounded maps
A linear map between two TVSs is called if it maps Banach disks to bounded disks.
A disk in is called if it absorbs every Banach disk.
An absorbing disk in a locally convex space is infrabornivorous if and only if its Minkowski functional is infrabounded.
A disk in a Hausdorff locally convex space is infrabornivorous if and only if it absorbs all compact disks (that is, if it is "").
Properties
Every bornivorous and infrabornivorous subset of a TVS is absorbing. In a pseudometrizable TVS, every bornivore is a neighborhood of the origin.
Two TVS topologies on the same vector space have that same bounded subsets if and only if they have the same bornivores.
Suppose is a vector subspace of finite codimension in a locally convex space and If is a barrel (resp. bornivorous barrel, bornivorous disk) in then there exists a barrel (resp. bornivorous barrel, bornivorous disk) in such that
Examples and sufficient conditions
Every neighborhood of the origin in a TVS is bornivorous.
The convex hull, closed convex hull, and balanced hull of a bornivorous set is again bornivorous.
The preimage of a bornivore under a bounded linear map is a bornivore.
If is a TVS in which every bounded subset is contained in a finite dimensional vector subspace, then every absorbing set is a bornivore.
Counter-examples
Let be as a vector space over the reals.
If is the balanced hull of the closed line segment between and then is not bornivorous but the convex hull of is bornivorous.
If is the closed and "filled" triangle with vertices and then is a convex set that is not bornivorous but its balanced hull is bornivorous.
See also
References
Bibliography
Topological vector spaces | Bornivorous set | [
"Mathematics"
] | 563 | [
"Topological vector spaces",
"Vector spaces",
"Space (mathematics)"
] |
64,267,707 | https://en.wikipedia.org/wiki/Countably%20quasi-barrelled%20space | In functional analysis, a topological vector space (TVS) is said to be countably quasi-barrelled if every strongly bounded countable union of equicontinuous subsets of its continuous dual space is again equicontinuous.
This property is a generalization of quasibarrelled spaces.
Definition
A TVS X with continuous dual space is said to be countably quasi-barrelled if is a strongly bounded subset of that is equal to a countable union of equicontinuous subsets of , then is itself equicontinuous.
A Hausdorff locally convex TVS is countably quasi-barrelled if and only if each bornivorous barrel in X that is equal to the countable intersection of closed convex balanced neighborhoods of 0 is itself a neighborhood of 0.
σ-quasi-barrelled space
A TVS with continuous dual space is said to be σ-quasi-barrelled if every strongly bounded (countable) sequence in is equicontinuous.
Sequentially quasi-barrelled space
A TVS with continuous dual space is said to be sequentially quasi-barrelled if every strongly convergent sequence in is equicontinuous.
Properties
Every countably quasi-barrelled space is a σ-quasi-barrelled space.
Examples and sufficient conditions
Every barrelled space, every countably barrelled space, and every quasi-barrelled space is countably quasi-barrelled and thus also σ-quasi-barrelled space.
The strong dual of a distinguished space and of a metrizable locally convex space is countably quasi-barrelled.
Every σ-barrelled space is a σ-quasi-barrelled space.
Every DF-space is countably quasi-barrelled.
A σ-quasi-barrelled space that is sequentially complete is a σ-barrelled space.
There exist σ-barrelled spaces that are not Mackey spaces.
There exist σ-barrelled spaces (which are consequently σ-quasi-barrelled spaces) that are not countably quasi-barrelled spaces.
There exist sequentially complete Mackey spaces that are not σ-quasi-barrelled.
There exist sequentially barrelled spaces that are not σ-quasi-barrelled.
There exist quasi-complete locally convex TVSs that are not sequentially barrelled.
See also
Barrelled space
Countably barrelled space
DF-space
H-space
Quasibarrelled space
References
Functional analysis | Countably quasi-barrelled space | [
"Mathematics"
] | 500 | [
"Functional analysis",
"Mathematical objects",
"Functions and mappings",
"Mathematical relations"
] |
64,268,157 | https://en.wikipedia.org/wiki/Ultrabarrelled%20space | In functional analysis and related areas of mathematics, an ultrabarrelled space is a topological vector spaces (TVS) for which every ultrabarrel is a neighbourhood of the origin.
Definition
A subset of a TVS is called an ultrabarrel if it is a closed and balanced subset of and if there exists a sequence of closed balanced and absorbing subsets of such that for all
In this case, is called a defining sequence for
A TVS is called ultrabarrelled if every ultrabarrel in is a neighbourhood of the origin.
Properties
A locally convex ultrabarrelled space is a barrelled space.
Every ultrabarrelled space is a quasi-ultrabarrelled space.
Examples and sufficient conditions
Complete and metrizable TVSs are ultrabarrelled.
If is a complete locally bounded non-locally convex TVS and if is a closed balanced and bounded neighborhood of the origin, then is an ultrabarrel that is not convex and has a defining sequence consisting of non-convex sets.
Counter-examples
There exist barrelled spaces that are not ultrabarrelled.
There exist TVSs that are complete and metrizable (and thus ultrabarrelled) but not barrelled.
See also
Citations
Bibliography
Topological vector spaces | Ultrabarrelled space | [
"Mathematics"
] | 253 | [
"Topological vector spaces",
"Vector spaces",
"Space (mathematics)"
] |
67,223,949 | https://en.wikipedia.org/wiki/H3R2me2 | H3R2me2 is an epigenetic modification to the DNA packaging protein histone H3. It is a mark that indicates the di-methylation at the 2nd arginine residue of the histone H3 protein. In epigenetics, arginine methylation of histones H3 and H4 is associated with a more accessible chromatin structure and thus higher levels of transcription. The existence of arginine demethylases that could reverse arginine methylation is controversial.
Nomenclature
The name of this modification indicates dimethylation of arginine 2 on histone H3 protein subunit:
Arginine
Arginine can be methylated once (monomethylated arginine) or twice (dimethylated arginine). Methylation of arginine residues is catalyzed by three different classes of protein arginine methyltransferases.
Arginine methylation affects the interactions between proteins and has been implicated in a variety of cellular processes, including protein trafficking, signal transduction, and transcriptional regulation.
Arginine methylation plays a major role in gene regulation because of the ability of the PRMTs to deposit key activating (histone H4R3me2, H3R2me2, H3R17me2, H3R26me2) or repressive (H3R2me2, H3R8me2, H4R3me2) histone marks.
Histone modifications
The genomic DNA of eukaryotic cells is wrapped around special protein molecules known as histones. The complexes formed by the looping of the DNA are known as chromatin.
Mechanism and function of modification
JMJD6, a Jumonji domain-containing protein, was reported to demethylate H3R2me2.
H3R2me2 is a major mark deposited by PRMT6. H3R2me1 and H3R2me2 marks are associated with highly expressed genes although H3R2me2 can block H3K4me3 effector molecules.
Epigenetic implications
The post-translational modification of histone tails by either histone-modifying complexes or chromatin remodeling complexes is interpreted by the cell and leads to complex, combinatorial transcriptional output. It is thought that a histone code dictates the expression of genes by a complex interaction between the histones in a particular region. The current understanding and interpretation of histones comes from two large scale projects: ENCODE and the Epigenomic roadmap. The purpose of the epigenomic study was to investigate epigenetic changes across the entire genome. This led to chromatin states, which define genomic regions by grouping different proteins and/or histone modifications together.
Chromatin states were investigated in Drosophila cells by looking at the binding location of proteins in the genome. Use of ChIP-sequencing revealed regions in the genome characterized by different banding. Different developmental stages were profiled in Drosophila as well, an emphasis was placed on histone modification relevance. A look in to the data obtained led to the definition of chromatin states based on histone modifications. Certain modifications were mapped and enrichment was seen to localize in certain genomic regions.
The human genome is annotated with chromatin states. These annotated states can be used as new ways to annotate a genome independently of the underlying genome sequence. This independence from the DNA sequence enforces the epigenetic nature of histone modifications. Chromatin states are also useful in identifying regulatory elements that have no defined sequence, such as enhancers. This additional level of annotation allows for a deeper understanding of cell specific gene regulation.
Clinical significance
As of March 2021, PRMT6-mediated H3R2me2 role in early embryonic development and ES cell identity are unclear.
Methods
The histone mark H3K4me1 can be detected in a variety of ways:
1. Chromatin Immunoprecipitation Sequencing (ChIP-sequencing) measures the amount of DNA enrichment once bound to a targeted protein and immunoprecipitated. It results in good optimization and is used in vivo to reveal DNA-protein binding occurring in cells. ChIP-Seq can be used to identify and quantify various DNA fragments for different histone modifications along a genomic region.
2. Micrococcal Nuclease sequencing (MNase-seq) is used to investigate regions that are bound by well-positioned nucleosomes. Use of the micrococcal nuclease enzyme is employed to identify nucleosome positioning. Well-positioned nucleosomes are seen to have enrichment of sequences.
3. Assay for transposase accessible chromatin sequencing (ATAC-seq) is used to look in to regions that are nucleosome free (open chromatin). It uses hyperactive Tn5 transposon to highlight nucleosome localisation.
See also
Histone methylation
Histone methyltransferase
References
Epigenetics
Post-translational modification | H3R2me2 | [
"Chemistry"
] | 1,069 | [
"Post-translational modification",
"Gene expression",
"Biochemical reactions"
] |
67,224,201 | https://en.wikipedia.org/wiki/Qatar%20Exoplanet%20Survey | The Qatar Exoplanet Survey, also known as QES, is an international exoplanet search survey based in Qatar. Its main goal is to detect exoplanets using the transit method, which is observing the light curve of the host star.
History
This survey has a site in New Mexico, which was a collaboration to find small planets in the northern sky. Before it found its own planets, it detected WASP-36b and WASP-37b.
Site
There is a telescope with 5 cameras, which are each 400m, which is also located in New Mexico. It has been operating since 2011 which occasional errors.
Results
- In 2011, QES announced the discovery of Qatar-1b, a hot Jupiter that has similar parameters to Jupiter.
- In 2016, QES discovered 3 massive planets, which are 4-6 times more massive than Jupiter. These planets are Qatar-3b, Qatar-4b, which is the largest, and Qatar-5b.
List
This list is incomplete and needs more information.
Light green indicates it orbits one of stars in a binary system.
References
Exoplanet search projects
Scientific organisations based in Qatar
Research in Qatar | Qatar Exoplanet Survey | [
"Astronomy"
] | 239 | [
"Astronomy projects",
"Exoplanet search projects"
] |
67,224,222 | https://en.wikipedia.org/wiki/Emotional%20hedge | An emotional hedge is a psychological and financial strategy used to mitigate potential negative emotions by offsetting a personally significant outcome with a compensatory action. The concept is most commonly applied in sports betting, where an individual places a wager against their favored team. If the team wins, the emotional satisfaction compensates for the financial loss; if the team loses, the financial gain cushions the emotional disappointment.
Reluctance
Despite the fact that an emotional hedge guarantees the bettor one positive outcome, it is rarely observed. Optimism bias, in which the probability of a positive outcome is overestimated by an emotionally-driven bettor, plays a part in many people's decision not to make the bet. In sports betting, many are also reluctant to make the bet because they feel that it is disloyal to their favored team.
See also
Hedge (finance)
Sports betting
References
Sports betting
Behavioral economics
Psychological concepts | Emotional hedge | [
"Biology"
] | 184 | [
"Behavior",
"Behavioral economics",
"Behaviorism"
] |
67,226,681 | https://en.wikipedia.org/wiki/Optical%20Space%20Infrared%20Downlink%20System | Optical Space Infrared Downlink System (OSIRIS) is an experimental program of DLR's Institute of Communications and
Navigation (at Stuttgart university, Germany).
OSIRISv1 was hosted on the Flying Laptop satellite. to test 200 Mbit/s.
OSIRISv2 was hosted on the BiROS satellite. to test 1 Gbit/s.
ORIRISv3 was due to test 10 Gbit/s from the ISS in 2020.
OSIRIS4cubesat are in development.
See also
Laser communication in space
References
Laser communication in space | Optical Space Infrared Downlink System | [
"Astronomy"
] | 119 | [
"Outer space stubs",
"Outer space",
"Astronomy stubs"
] |
67,227,898 | https://en.wikipedia.org/wiki/Edmond%E2%80%93Ogston%20model | The Edmond–Ogston model is a thermodynamic model proposed by Elizabeth Edmond and Alexander George Ogston in 1968 to describe phase separation of two-component polymer mixtures in a common solvent. At the core of the model is an expression for the Helmholtz free energy
that takes into account terms in the concentration of the polymers up to second order, and needs three Virial coefficients and as input. Here is the molar concentration of polymer , is the universal gas constant, is the absolute temperature, is the system volume. It is possible to obtain explicit solutions for the coordinates of the critical point
,
where represents the slope of the binodal and spinodal in the critical point. Its value can be obtained by solving a third order polynomial in ,
,
which can be done analytically using Cardano's method and choosing the solution for which both and are positive.
The spinodal can be expressed analytically too, and the Lambert W function has a central role to express the coordinates of binodal and tie-lines.
The model is closely related to the Flory–Huggins model.
The model and its solutions have been generalized to mixtures with an arbitrary number of components , with greater or equal than 2.
References
Polymer chemistry
Solutions
Thermodynamic free energy | Edmond–Ogston model | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 263 | [
"Thermodynamics stubs",
"Thermodynamic properties",
"Physical quantities",
"Materials science",
"Homogeneous chemical mixtures",
"Thermodynamic free energy",
"Energy (physics)",
"Thermodynamics",
"Polymer chemistry",
"Solutions",
"Wikipedia categories named after physical quantities",
"Physica... |
67,228,120 | https://en.wikipedia.org/wiki/Anaeramoeba | Anaeramoeba is a genus of anaerobic protists of uncertain phylogenetic position, first described in 2016.
Description
As the name implies, Anaeramoeba are anaerobic amoeboid organisms which form a fan-like shape similar to that of Flamella. At least two species can also sometimes assume flagellate forms; with either two or four flagella. They contain double-membrane bound organelles called hydrogenosomes, assumed to be derived from mitochondria, usually associated with colonies of unidentified, rod-shaped bacteria.
Discovery and classification
Anaeramoeba specimens were first isolated in 2016, from samples shallow water anoxic ocean sediments collected from around the world. Despite the similarities to Flamella in both morphology and environment, genetic analyses found that Anaeramoeba do not belong within Amoebozoa. The precise phylogenetic position was not identified with strong support, and the genus may represent a newly identified, deep-branching group of protists. Recent classifications have listed them as sister to Parabasalia in Metamonada.
References
Eukaryote genera
Anaerobes
Amoeboids
Metamonads | Anaeramoeba | [
"Biology"
] | 239 | [
"Eukaryotes",
"Eukaryote stubs",
"Bacteria",
"Anaerobes"
] |
67,228,251 | https://en.wikipedia.org/wiki/Jean-Fran%C3%A7ois%20Groff | Jean-François Groff is a telecommunication engineer, and one of the key figures in the early development of the World Wide Web at CERN. He worked in close collaboration with Tim Berners-Lee, and helped define the HTTP protocol and HTML language. Groff is also the CTO and founder of Studio KOH, and CEO of Mobino, a mobile payments company headquartered in Geneva, Switzerland.
Background
Groff was first introduced to computers as a young boy, around 7 or 8 years of age, by his father, a computer engineer for Saint-Gobain. Young Groff began developing his programming skills on the personal computers that were available to him at home, including Amstrad, and later Atari computers. He graduated with a telecommunications degree from Telecom Paris.
Works
Groff co-authored an article titled The World-Wide Web: The Information Universe with Tim Berners-Lee, Robert Cailliau and Bernd Pollermann, first published in 1992 and again in 2010 in Computer Networks and ISDN Systems: The International Journal of Computer and Telecommunications Networking.
References
Living people
Web developers
Telecommunications engineers
Year of birth missing (living people)
People associated with CERN | Jean-François Groff | [
"Engineering"
] | 239 | [
"Telecommunications engineering",
"Telecommunications engineers"
] |
67,229,057 | https://en.wikipedia.org/wiki/Differential%20fitness | Differential fitness is the third of Darwin's four postulates for natural selection. It states that survival and reproduction rates vary between individuals. Fitness differentials are widespread and detectable throughout nature. This fitness differential is visible in several ways, and it can be detected throughout nature. It can be based on behavioral differences that can act with or against environmental changes; one notable example was a 2014 study of snowshoe hares, where researchers found that white snowshoe hares did not change their behavior due to increased snow melt. Subsequent research found that brown hares survived and bred more than the white snowshoe hares. Differential fitness can also be applied between species. Researchers found that the Neotoma macrotis wood rat in the California woodlands was responding to climate change by moving into a hybrid zone, and this gave it an advantage over the competing Neotoma fuscipes Differential fitness can also apply to multiple traits at once and at unequal levels. A study with Linum pubescens found that its floral traits were based on multiple different fitness factors. Differential fitness can also be based on the sex of organisms. Researchers found that there were differential survival rates between mothers and fathers in the mid-nineteenth century in Utah.
Behavioral response differential fitness
Differential fitness can be based on responses to the environment, and these responses are variable. While some organisms may have the best phenotype for certain conditions, those with suboptimal phenotypes can attempt to compensate with behavioral changes. However, these changes are not always made. A 2014 study examined some of the effects of climate change on snowshoe hares (Lepus americanus) in the Arctic. The researchers found that while the new conditions, due to increased snow melt, favored brown snowshoe hares, uncamoflagued white snowshoe hares didn't change their behavior. Subsequent research in 2016 found that this failure to compensate led to decreased survival and fitness in the white snowshoe hares and in increased fitness in the brown snowshoe hares. However, environmental changes can also have deleterious behavioral impacts on individuals and populations. A 2014 study found that southern elephant seal (Mirounga leonina) females had a lower fitness due to behavioral changes attributed to climate change. They spent more time looking for food than eating, and simulations based on this behavioral shift pointed to reduced populations due to malnourished seal pups. These changes led to significant long-term deleterious effects on the population when the simulations modeled for a persistent behavioral change.
Differential fitness between species
Differential fitness can be readily examined through interspecific interactions such as competition and predation. A changing environment can give certain species an advantage over others, and new environments can lead to new opportunities for species. One 2017 study found that two competing woodrat species (Neotoma fuscipes and Neotoma macrotis) in California responded to climate change differently; the smaller N. macrotis that utilized the hybrid zone in its range more effectively had the fitness advantage. Invasive species illustrate an extreme fitness differential. Since they usually lack direct counters in new environments, they have massive advantages over local competitors and prey. A 2018 study found that the New England cottontail (Sylvilagus transitionalis) was often outcompeted by the invasive eastern cottontail (Sylvilagus floridanus) due to woodland clearing. While both species could utilize the invasive plants, the eastern cottontails had a fitness advantage over the native species in the same expanding environment, and this has led to the decline of the New England cottontail. The Burmese pythons (Python bivittatus) in Florida also present a stark example of differential fitness due to competition and predation by an invasive species upon native predators such as the raccoon. A 2017 study found that pythons within the Everglades had eliminated the local rabbits, and that they had also nearly eliminated the local opossum, raccoon, and bobcat populations due to their fitness advantages.
Multitrait differential fitness
An individual's fitness is often determined by multiple traits, and these traits might respond to different selective pressures. The interplay between these traits and their pressures will impact an organism's fitness. For example, multiple floral traits can have different fitness benefits and pressures due to pollinators and environmental conditions. A 2017 study with Linum pubescens found that various traits had different fitness measures. Traits such as flower width and seed characteristics had different fitness measures and selective pressures. Animals are also subject to differential fitness due to multiple traits and pressures, and overarching pressures can act as fitness determinants. Traits such as color, shape, and vocalizations can be influenced by various factors, and they have different fitness contributions. A 2009 study examined the vocalizations, color, and shape in the Amazonian frog Allobates femoralis and the pressures that affected them. The researchers found that geography and mimicry acted independently on vocalizations and color, but shapes remained the same due to fitness pressures.
Sex-based differential fitness
Individual fitness within a species is often determined by sex differences, and this often leads to differential fitness along those sex differences . Males can be the sex with higher fitness compared to individual females, and this is often illustrated in systems where male choice is more important (polygyny) or when males are larger than the females. Females may suffer and die due to childbirth in mammals, and this reduces their fitness compared to the males of the species. A 2007 study investigated the female and male mortality rates of human residents of Utah during the mid-nineteenth century, and they found that females died more often than males. This was often due to difficult and repeated childbirth in the region, and the loss of the female was more detrimental for the offspring than the loss of the male. Sex-based differential fitness can also favor females, and this is often illustrated in systems where female choice is more important or when females are larger than the males. However, these trends are not absolute. The differential fitness between sexes, like fitness due to environmental changes, can be negated by behavioral changes on the part of one of the sexes. The praying mantis females have been known to kill the males during mating. However, a 2017 study found that males can avoid this outcome via a behavioral change. The researchers found that the males in the praying mantis species Tenodera. angusitipennis ensured their survival by choosing fatter and less hungry females over skinnier ones, and this gave them a fitness advantage due to increased survival and reproduction.
RNA world
It is widely assumed that “life” emerged in the prebiotic world when an informational molecule (usually considered to be similar to RNA) acquired the ability to replicate itself and undergo natural selection based on differential fitness. Among competing nucleotide sequence-dependent configurations of replicating RNA, differential fitness would determined the outcome of natural selection among the RNA replicators. As the evolution of such RNA replicators continued, sequences that balanced the conflicting needs of survival and replication would be selected.
References
Natural selection
Charles Darwin | Differential fitness | [
"Biology"
] | 1,436 | [
"Evolutionary processes",
"Natural selection"
] |
67,234,378 | https://en.wikipedia.org/wiki/Soci%C3%A9t%C3%A9%20Coloniale%20des%20Chaux%20et%20Ciments%20de%20Portland%20de%20Marseille | The Société Coloniale des Chaux et Ciments de Portland de Marseille (Colonial Company for Lime and Portland Cements in Marseille) owned and operated cement works in L'Estaque near Marseille in the department of Bouches-du-Rhône.
History
The joint-stock company was founded on 20 November 1913 with a share capital of 4 million francs for a period of 50 years. The initial capital was increased to 2.5 mio francs in 1919, to 4.25 mio francs in April 1923 and to 5 mio francs in May 1929.
Messrs M. Siegfried, A. Cailler, J. Lindenmeyer, G. Bonnet, P. Bourcart, H. Gunthert, G. Roussy and M. Obellianne were appointed to the Board of Directors.
Purpose of the Company
The objectives of the company were as follows:
Manufacture, sale and export of lime, cement and hydraulic products.
Acquisition, lease, development and operation of lime and cement quarries in the department of Bouches-du-Rhône or in another region, in particular the quarries in La Nerthe.
Acquisition, construction and operation of all plant necessary for the company and the development of buildings and all movable and immovable property transactions.
Industrial or financial operations related to the above objects.
Narrow gauge railway
The company operated a works-owned Decauville railway with a gauge of from the quarries to the cement factory .
Shipping
Finished products destined for export were transported by lorry to the Port de la Lave, where they were loaded onto cargo ships. Two methods were used for this:
'A la chenille', packed in bags as general cargo via a conveyor belt.
'A la palanquée', packed in sacks as general cargo by crane over a ramp.
See also
Decauville wagon
References
Cement companies
Lime kilns
History of mining in France
600 mm gauge railways in France
Decauville
Bouches-du-Rhône
Provence-Alpes-Côte d'Azur | Société Coloniale des Chaux et Ciments de Portland de Marseille | [
"Chemistry",
"Engineering"
] | 411 | [
"Lime kilns",
"Kilns"
] |
61,936,551 | https://en.wikipedia.org/wiki/Maximally%20matchable%20edge | In graph theory, a maximally matchable edge in a graph is an edge that is included in at least one maximum-cardinality matching in the graph. An alternative term is allowed edge.
A fundamental problem in matching theory is: given a graph G, find the set of all maximally matchable edges in G. This is equivalent to finding the union of all maximum matchings in G (this is different than the simpler problem of finding a single maximum matching in G). Several algorithms for this problem are known.
Motivation
Consider a matchmaking agency with a pool of men and women. Given the preferences of the candidates, the agency constructs a bipartite graph where there is an edge between a man and a woman if they are compatible. The ultimate goal of the agency is to create as many compatible couples as possible, i.e., find a maximum-cardinality matching in this graph. Towards this goal, the agency first chooses an edge in the graph, and suggests to the man and woman on both ends of the edge to meet. Now, the agency must take care to only choose a maximally matchable edge. This is because, if it chooses a non-maximally matchable edge, it may get stuck with an edge that cannot be completed to a maximum-cardinality matching.
Definition
Let G = (V,E) be a graph, where V are the vertices and E are the edges. A matching in G is a subset M of E, such that each vertex in V is adjacent to at most a single edge in M. A maximum matching is a matching of maximum cardinality.
An edge e in E is called maximally matchable (or allowed) if there exists a maximum matching M that contains e.
Algorithms for general graphs
Currently, the best known deterministic algorithm for general graphs runs in time .
There is a randomized algorithm for general graphs in time .
Algorithms for bipartite graphs
In bipartite graphs, if a single maximum-cardinality matching is known, it is possible to find all maximally matchable edges in linear time - .
If a maximum matching is not known, it can be found by existing algorithms. In this case, the resulting overall runtime is for general bipartite graphs and for dense bipartite graphs with .
Bipartite graphs with a perfect matching
The algorithm for finding maximally matchable edges is simpler when the graph admits a perfect matching.
Let the bipartite graph be , where and . Let the perfect matching be .
Theorem: an edge e is maximally matchable if-and-only-if e is included in some M-alternating cycle - a cycle that alternates between edges in M and edges not in M. Proof:
If e is in an alternating cycle, then either e is in M, or - by inverting the cycle - we get a new perfect matching that contains e. Hence, e is maximally matchable.
Conversely, if e is maximally matchable, then it is in some perfect matching N. By taking the symmetric difference of M and N, we can construct an alternating cycle that contains e.
Now, consider a directed graph , where and there is an edge from to in H iff and there is an edge between and in G (note that by assumption such edges are not in M). Each M-alternating cycle in G corresponds to a directed cycle in H. A directed edge belongs to a directed cycle iff both its endpoints belong to the same strongly connected component. There are algorithms for finding all strongly connected components in linear time. Therefore, the set of all maximally matchable edges can be found as follows:
Given the undirected bipartite graph and the perfect matching M, mark every edge in M as maximally matchable.
Construct the directed graph as above.
Find all strongly connected components in H.
For each i, j such that are in the same component, mark the edge as maximally matchable.
Mark all remaining edges as not maximally matchable.
Bipartite graphs without a perfect matching
Let the bipartite graph be , where and and . Let the given maximum matching be , where . The edges in E can be categorized into two classes:
Edges with both endpoints saturated by M. We call such edges M-upper.
Edges with exactly one endpoint saturated by M. We call such edges M-lower.
Note that there are no edges with both endpoints unsaturated by M, since this would contradict the maximality of M.
Theorem: All -lower edges are maximally matchable. Proof: suppose where is saturated and is not. Then, removing from and adding yields a new maximum-cardinality matching.
Hence, it remains to find the maximally matchable edges among the M-upper ones.
Let H be the subgraph of G induced by the M-saturated nodes. Note that M is a perfect matching in H. Hence, using the algorithm of the previous subsection, it is possible to find all edges that are maximally matchable in H. Tassa explains how to find the remaining maximally matchable edges, as well as how to dynamically update the set of maximally matchable edges when the graph changes.
References
Graph theory
Matching (graph theory) | Maximally matchable edge | [
"Mathematics"
] | 1,075 | [
"Discrete mathematics",
"Graph theory",
"Combinatorics",
"Mathematical relations",
"Matching (graph theory)"
] |
61,936,794 | https://en.wikipedia.org/wiki/Rescue%20of%20Sea%20Nymph | The rescue of Sea Nymph was the United States Navy's safe recovery of two crew from the sailboat Sea Nymph, which had been adrift in the Pacific Ocean for more than five months.
In May 2017, sailor Jennifer Appel and landsman Tasha Fuiava left Honolulu with their two dogs aboard a fully stocked and equipped Sea Nymph. According to the women, on their first night afloat, their boat took damage from a "force 11 storm"; further damage was inflicted by a typhoon, leaving the boat functionally adrift and incommunicado. Tiger shark attacks, a white squall, and Fuiava's inexperience supposedly caused further problems for the four.
Almost six months after leaving Hawaii, Sea Nymph was spotted by a Taiwanese fishing vessel, and though Appel would later claim the larger boat was attacking theirs, she was able to use their satellite phone to contact the United States Coast Guard for help. arrived to rescue Appel, Fuiava, and their dogs, but left Sea Nymph adrift after determining it to be unseaworthy.
After their rescue and the media attention it garnered, the two-woman crew of the erstwhile Sea Nymph were questioned about many aspects of their story. Experts in sailing, meteorology, Hawaiian seamanship, and marine biology, as well as the Coast Guard and the Taipei Economic and Cultural Representative Office disputed claims made. Appel continued to stand by their statements. If unrecoverable, she could not collect Sea Nymph insurance, though the ship was spotted still afloat about four months later.
Background
Jennifer Appel (born ) and Tasha Fuiava (born ) were residents of Hawaii, and met in December 2016. Within a week of meeting, they had planned an 18-day trip, sailing to Tahiti— Appel was an experienced sailor while Fuiava was a novice. Appel wrecked her first boat, a fiberglass sloop, in 2012.
Sea Nymph is a sailboat, and was stocked with two desalinators as well as non-perishables such as "beef jerky, oatmeal, rice, pasta, dried fruits, [and] nuts". The boat was also equipped with a properly registered, fully operational emergency position-indicating radiobeacon (EPIRB).
Adrift
Appel and Fuiava were residents of Honolulu, living with two dogs (Zeus and Valentine) aboard their sailboat Sea Nymph. The women said they set sail from Hawaii on May 3, 2017 for an 18-day, voyage to Tahiti, but encountered a "force 11 storm" (winds between , waves from ) that same night. This initial storm lasted three nights and three days. Four days later, the boat's spreader broke. The pair considered returning to Hawaii, but did not because they believed the harbors at Maui and Lanai were not deep enough to accommodate Sea Nymph.
Further problems occurred, including tiger shark attacks, damage to their engine and mast, and malfunctions in their radiotelephone and Iridium satellite phone. Lacking communications, Sea Nymph failed to avoid a typhoon with winds and waves.
The women headed for Kiribati, but couldn't land due to the broken communications equipment. The Cook Islands were their next target, but a white squall and Fuiava's inexperience pushed them further west. On October 1, Sea Nymph came within of Wake Island, and the women aboard managed to contact officials there. However, the boat was on the wrong side of the island to receive assistance, and both the swell and winds were pushing them westward, preventing them from looping around.
Rescue
On October 24, southeast of Japan, Sea Nymph was spotted by a Taiwanese fishing vessel.
Initial reports say the Taiwanese notified the United States Coast Guard (USCG) in Guam, and began towing the lost boat, compromising its hull. Once they knew rescue was on its way, Appel and Fuiava began broadcasting a mayday. Appel later changed this part of her story, saying the Taiwanese ship had instead attacked Sea Nymph by intentionally failing to keep the appropriate towing distance and colliding with the much smaller vessel: "The Taiwanese fishing vessel was not planning to rescue us […] They tried to kill us during the night." Appel claimed she was able to use the Taiwanese satellite phone and alert the USCG of all this because nobody aboard the Taiwanese ship spoke English.
was on a routine deployment nearby, and arrived on October 25 at 10:30a.m. Rescuing the two women and two dogs at 1:18p.m., the Navy determined Sea Nymph to be unseaworthy and left the boat adrift off the coast of Asia. Appel and Fuiava were given "medical assessments, food, and berthing arrangements" aboard Ashland until the ship could deliver the four to its next port of call: White Beach Naval Facility, a US Naval base in Okinawa. In a press conference aboard Ashland, Appel stated that, "Had they not been able to locate us, we would have been dead within 24 hours".
Upon arriving in Okinawa on October 30, Zeus and Valentine were quarantined while Appel and Fuiava recovered at the US consulate in Naha.
Inconsistencies
Asked about the unused EPIRB by CNN, United States Coast Guard (USCG) PO2 Tara Molle said, "I can't speculate as to why they wouldn't have activated it." On 31 October, Appel said that they didn't activate the EPIRB because their boat was still seaworthy; "EPIRB calls are for people who are in an immediate life threatening scenario […] It would be shameful to call on the USCG resources when not in imminent peril and allow someone else to perish because of it." She followed this up saying, "Had we known our calls were going nowhere — we would have used the EPIRB — but hindsight is 20/20". On November 8, Appel told Today Matt Lauer that after activating the EPIRB, it would have taken emergency services 4–24 hours to arrive; the USCG disputed such a delay, citing "cases in remote Alaska where a ship in distress just using one form of beacon brought a fairly quick response from nearby fishing boats and the Coast Guard." Appel defended their decision saying, "we took our chances with the man upstairs, who gave us grace and allowed us to still be here today." After she amended her version of events with the alleged Taiwanese attack on Sea Nymph, Appel said she eschewed the EPIRB because it would have immediately alerted the Taiwanese captain, as opposed to her telephoning Guam and relaying her emergency in English.
Appel and Fuiava said they encountered a "force 11 storm" on May 3. Though the National Weather Service in Hawaii issued a small craft advisory for the ʻAlenuihāhā and Pailolo Channels that day, it recorded "no organized storm systems near the Hawaiian Islands on the dates of May 3, 2017 or the few days afterward."
Not only is the claim that Maui and Lanai harbors could not accommodate Sea Nymph untrue, but Hawaiʻi has multiple such places to dock. Furthermore, Appel's descriptions of other landing opportunities not taken seem to assume that Kiritimati (population over 2,000 people) was uninhabited. As for the claims of tiger shark attacks, marine biologists refuted this, saying that the macropredators don't behave that way, nor do they grow to the lengths reported.
On October 30, USCG spokesperson Lt. Scott Carr announced that in June, the Coast Guard contacted a ship calling itself Sea Nymph in the vicinity of Tahiti. That ship's captain said their ship was in no distress, and would make landfall the next day. According to the timeline given by Appel and Fuiava, this interaction happened after they allegedly had loss of engine and mast/rigging damage. On Today, Appel produced a GPS tracking unit, claiming that it was from her boat, and that it recorded Sea Nymph "nowhere near Tahiti".
As for Appel's allegations against the Taiwanese ship, the Taipei Economic and Cultural Representative Office called them untrue, citing the Taiwanese vessel's "GPS and a satellite system that automatically submits its track, location, and speed to a 24-hour monitoring center. […] the fishing vessel stopped sailing right after spotting Ms. Appel's boat and never attempted to ram against their vessel or kill them as she claimed".
Aftermath
Of the inconsistencies, the United States Navy stated that it doesn't investigate such incidents, while , the Coast Guard was still reviewing the case.
Appel and Fuiava's story received enough attention that a tabloid published nude photos of the older woman from her time as a dominatrix in the 2000s. Furthermore, prior to ceasing contact altogether, Appel's family in Texas told her they didn't want her to return home.
By mid-November 2017, both women were in New York City, having been flown there by Today. In an interview with The Guardian, they each expressed a desire to return to the sea, preferably aboard a recovered Sea Nymph. If Sea Nymph is unrecoverable, Appel cannot receive its insurance money because it was abandoned more than from shore. Zeus and Valentine required vaccinations before they could return to Hawaii, but Appel left her wallet aboard the boat, and was running out of cash. Since the dogs could not return to Hawaii until December at the earliest, Appel and Fuiava were planning a trans-continental road trip saying, "Eventually, we're either going to find out my boat has been found or we're going to start working on a new boat […] We are incredibly appreciative of the navy, […] if I had it to do again, I would just keep going."
During the 2017–2018 Volvo Ocean Race, Sea Nymph was spotted by Turn the Tide on Plastic on February 13 (UTC) during the sixth leg of the yacht race. Turn the Tide on Plastic was between Hong Kong and Auckland, approximately east of Guam. Captain Dee Caffari described the abandoned boat as "sitting pretty low in the bow and her mainsail was washed over the side but the rest of her looked like she would make a nice cruiser." In the interests of the race, Sea Nymph was left where it was found, "a hazard to shipping, a risk to islands, reefs and atolls and slowly not going anywhere."
References
External links
2017 controversies
Sea Nymph
sea rescue
transport controversies | Rescue of Sea Nymph | [
"Physics"
] | 2,258 | [
"Physical systems",
"Transport",
"Transport controversies"
] |
61,936,973 | https://en.wikipedia.org/wiki/Sadfishing | Sadfishing is a term used to describe a behavioural trend where people make exaggerated claims about their emotional problems to generate sympathy. The name is a play on "catfishing." Sadfishing is a common reaction for someone going through a hard time, or pretending to be going through a hard time. Sadfishing is said to hurt younger people, exposing them to bullying and child grooming. This is due to people sharing their personal and emotional stories online, a practice which sometimes result in the individual sharing the story being targeted by online abusers.
Another consequence of this behaviour is that people with "real problems" end up being overlooked or even accused of sadfishing themselves and being bullied for it.
Young people who seek support online have started being accused of sadfishing, a report has said. The report says that the accusations of sadfishing could further harm young people with mental health problems. Sadfishing is related to cyberbullying, and is often looked upon as a method of attention seeking. Sadfishing has been said to attract bullies and paedophiles.
Background
The first known usage of the word sadfishing was in January 2019, in an article for the Metro, written by Rebecca Reid in reference to Kendall Jenner's Instagram posts about her acne problems, posting pictures of herself while talking about it. The term was later picked up by Good Morning Britain, where they did an interview and talked about it. It started trending on social media at the start of October 2019, with several news channels and newspapers picking it up.
Potential causes
Sadfishing can be caused by many things, the main reason being that someone doesn't get enough attention, and/or has low self-respect. This is proven by the fact that people sadfishing are looking for compliments: very close to narcissistic behaviour, but with desire for compliments from other people for self-satisfaction. Research has found that individuals engaging in sad-fishing tend to have an anxious attachment style. Sometimes adults partake in sadfishing because of jealousy. When someone finds themselves threatened by another person who takes all the attention, they may respond with sadfishing behaviour. Loneliness can result in sadfishing as well; by posting about their emotional problems, people tend to crave attention. Posts about anxiety and depression are really common while sadfishing, as people tend to show care and give attention to the one sadfishing. Another reason for sadfishing can be that someone feels uncomfortable sharing feelings with their close friends or family, and as a result they turn to social media to share feelings for sympathy and attention. Anti-social behaviour can lead to sadfishing as well: if someone has no friends and no one to talk to, they often end up sharing it online. Another reason for sadfishing can be trolling; people will troll and see if they can hook an audience onto themselves. Sadfishing can also be because of actually wanting help; people tend to sadfish in order to feel better, after letting people know that they need help.
Separating sadfishing from crisis
It can be difficult to tell if a person is looking for support, sympathy, or if the person is at risk for harming themselves. This is due to the fact that social media often lacks context and the ability to read nonverbal cues, says Dr. Lindsey Giller, a clinical psychologist in New York. People at risk for suicide will show other signs in addition to talking about suicide; such as a deepening depression, expression of feeling trapped, feelings of worthlessness, or a preoccupation with death. They may even post online if they are considering suicide or self-harm; this can help stop suicide or self-harm if taken seriously. Taking people seriously is a must, as talking about suicide can be a plea for help, and can also be a late sign in the progression towards a suicide attempt. There is no way to know if a friend is suffering or in crisis, or is only seeking attention, especially if you're not a mental health professional. As such, each alarming post should be taken seriously, notes Dr. Jelena Kecmanovic, a clinical psychologist in Arlington, Virginia.
See also
Attention seeking
Cyberbullying
References
Digital media use and mental health
Human behavior
Internet slang
Slang
Texting codes | Sadfishing | [
"Biology"
] | 889 | [
"Behavior",
"Human behavior"
] |
61,937,329 | https://en.wikipedia.org/wiki/Margit%20Voigt | Margit Voigt is a German mathematician specializing in graph theory and graph coloring. She is a professor of operations research at the University of Applied Sciences Dresden.
Voigt completed her Ph.D. in 1992 at the Technische Universität Ilmenau. Her dissertation, Über die chromatische Zahl einer speziellen Klasse unendlicher Graphen [On the chromatic number of a special class of infinite graphs] was jointly supervised by Rainer Bodendiek and Hansjoachim Walther.
Her results include the first known planar graph that requires five colors for list coloring, and a counterexample to a related conjecture that list coloring of planar graphs requires at most one more color than graph coloring for the same graphs.
References
20th-century German mathematicians
21st-century German mathematicians
German women mathematicians
Graph theorists
Year of birth missing (living people)
Living people
Ilmenau University of Technology alumni | Margit Voigt | [
"Mathematics"
] | 196 | [
"Mathematical relations",
"Graph theory",
"Graph theorists"
] |
61,942,798 | https://en.wikipedia.org/wiki/Alan%20Powell%20Goffe | Alan Powell Goffe (9 July 1920 – 13 August 1966) was a British pathologist whose research contributed to the development and improvement of vaccines, most notably the polio and measles vaccines. He was a Fellow of the Royal Microscopical Society, a Fellow of the Royal Society of Medicine and a member of the Pathological Society of Great Britain and Ireland. At the time of his death he was the head of the Department of Experimental Cytology at the Wellcome Research Laboratories.
Education
Goffe was born in 1920 to a black Jamaican father and a white English mother, who were both practising physicians. After attending Epsom College in Surrey, England, Goffe graduated in 1944 from University College Hospital with a medical degree. Goffe then specialised in pathology, first as a Pathological Assistant at the London Hospital and then at the Central Public Health Laboratory, taking some time out from the latter to complete a Diploma in Bacteriology at the London School of Hygiene & Tropical Medicine.
Career
During his two years serving as Specialist in Pathology in the Royal Army Medical Corps, some of which was spent in Egypt, he turned his focus to intestinal pathogens such as typhoid.
Once his national service had been completed, Goffe returned to the Central Public Health Laboratory, where he studied the poliomyelitis virus and helped to introduce cutting-edge techniques developed by Enders in the US to the UK. He set up a tissue-culture laboratory; worked on preparing inactivated versions of the virus; and was a member of a Medical Research Council (United Kingdom) committee aiming to bring learning from the US to develop a vaccine in Britain.
In 1955 Goffe moved to the Wellcome Research Laboratories in Kent, where he worked as the Chief Medical Virologist. During his time at Wellcome he made important contributions not only to poliomyelitis vaccines, but also led on the development of an attenuated measles strain known as the "Beckenham" (also sometimes known as the "Goffe") strain. Goffe was involved in numerous clinical trials to test vaccines, publicly testing them on himself and his family to demonstrate his confidence in their safety. His interest in how some viruses could cause tumours led him to study the SV40 virus and the human wart virus, human papillomavirus.
Two years before his death he was given the task of setting up a new Department of Experimental Cytology, unusual in that it was the first department dedicated to fundamental research at the Wellcome Laboratories.
Personal life
Goffe and his wife Elisabeth, who was a teacher, married in 1943 and had five children. Their son Hugh died from bone cancer aged 15, after which they set up the Hugh Goffe Foundation in his memory. At the age of 46 Goffe was drowned in an accident whilst sailing near the Isle of Wight.
See also
Alfred Constantine Goffe
References
1920 births
1966 deaths
British pathologists
British expatriates in Egypt
People educated at Epsom College
Deaths by drowning in the United Kingdom
20th-century British medical doctors
British people of Jamaican descent
Vaccinologists
People from Kingston, Jamaica
Black British health professionals | Alan Powell Goffe | [
"Biology"
] | 641 | [
"Vaccination",
"Vaccinologists"
] |
61,943,715 | https://en.wikipedia.org/wiki/Sin%C3%A9ad%20M.%20Ryan | Sinéad M. Ryan is an Irish theoretical physicist and professor of Theoretical High Energy Physics at Trinity College Dublin. Her research covers "high-energy particle physics, and how particles in atoms such as quarks and gluons stick together".
Education and career
Ryan started her third-level education at University College Cork, Ireland in 1988 where she earned a first class honours for her B.Sc. After her bachelor's degree, she completed a research M.Sc. in 1993. In 1996, Ryan completed her Ph.D. at The University of Edinburgh.
After the completion of her Ph.D. she became a research associate at Fermi National Accelerator Laboratory (1996–1999). She then held a number of positions at Trinity College Dublin (TCD): Lecturer in High Performance Computing (1999–2000), Tenured Lecturer (2000–2006), Senior Lecturer (2006–2012), Professor (2012–2016), Head of the School of Mathematics (2012–2016), and finally, Chair of Theoretical High Energy Physics (2016–Present).
Since 2000, Ryan has been a journal, grant referee, and institutional reviewer for Physical Review D (PRD), Physical Review Letters (PRL), Physics Letters B (PLB), National Science Foundation (NSF), Natural Sciences and Engineering Research Council of Canada (NSERC), Science and Technology Facilities Council (STFC), and Irish Research Council (IRC).
Ryan has served as a member of Wilson Prize in Lattice QCD Committee as well as on the International Advisory Committee for the Symposium in Lattice Field Theory at CERN from 2013 to the present. She was a founding academic partner of the Trinity Walton Club in 2014.
She has served as chair of the PANDA Theory Advisory Group from 2016 to present as well as the chair of the PRACE Scientific Steering Committee from 2017 to present.
In 2023 she was elected a member of the Royal Irish Academy.
Selected publications
Ryan's work ranges from quantum chromodynamics, and lattices, to particle collisions and muons.
Supports
Ryan is a strong supporter of encouraging students, especially female students, in pursuing maths and physics in third level education. In her words, "I think we need to encourage girls to believe they can do maths and physics... it might not always be easy, but it’s worth doing". And she believes it is "important for young students to see that women have done this and it’s not impossible to have a career in maths or physics". She is also a supporter of funding for the Science Foundation Ireland.
References
Alumni of University College Cork
Alumni of the University of Edinburgh
Academics of Trinity College Dublin
Theoretical physicists
Irish women physicists
21st-century Irish physicists
21st-century women physicists
Living people
Year of birth missing (living people)
21st-century Irish women scientists
Members of the Royal Irish Academy | Sinéad M. Ryan | [
"Physics"
] | 595 | [
"Theoretical physics",
"Theoretical physicists"
] |
61,945,189 | https://en.wikipedia.org/wiki/Surface%20Pro%207 | The Surface Pro 7 is a 2-in-1 detachable tablet computer developed by Microsoft. It is the seventh generation of Surface Pro and was announced alongside the Surface Laptop 3 and Surface Pro X at an event on 2 October 2019. An updated version of the device was introduced on 11 January 2021 called the Surface Pro 7+. Surface Pro 7 and 7+ maintain the same form and design as previous models but with the Mini DisplayPort receptacle replaced by a USB-C port. The display of the device is the same as the previous model with a 2736 x 1824 resolution touchscreen in 3:2 aspect ratio and 267 ppi. The Surface Pro 7 starts at $750 and goes up to $2,300. The Surface Pro 7+ for Business starts at $900 and goes up to $2,800.
Microsoft started offering the Surface Pro 7+ to consumers as announced at their Surface Event on September 22, 2021.
Hardware
The Surface Pro 7 is the 7th addition to Surface Pro lineup. The tablet is aimed towards professionals while the Surface Pro 7+ an updated version aimed towards the enterprise.
The Surface Pro 7+ comes with a removable SSD while the Surface Pro 7 does not.
Both are available with a 12.3-inch LCD touchscreen display and features a full-body magnesium alloy construction in platinum and black finish.
The device is the first Surface Pro to contain a USB-C port with power delivery.
The kickstand is still present just like previous models and unfolds from 0 degrees to 165 degrees.
The Surface Pro 7 includes 1 USB-C port, 1 USB A port, 1 3.5 mm audio port, 1 microSD card port (non-LTE models), and a Surface Connect port.
The Surface Pro 7 size is 11.5 x 7.9 x 0.33 inches and weighs ~1.7 pounds.
The Surface Pro 7's battery is 43.2Wh which offers battery life of ~8 hours. The Surface Pro 7+ for Business battery is 50.4Wh for even longer life.
Software
Surface Pro 7+ for Business models ship with a pre-installed 64-bit version of Windows 10 Pro; consumer models ship with a pre-installed 64-bit version of Windows 10 Home. Windows 10 comes pre-installed with Mail, Calendar, People, Xbox, Photos, Movies and TV, Groove, Your Phone, a 30-day trial of Office 365, and the Edge browser. The device also supports Windows Hello login using biometric facial recognition.
Configuration
Consumer models come preloaded with Windows 10 HomeBusiness models come preloaded with Windows 10 Pro
Timeline
References
Microsoft Surface
2-in-1 PCs
Tablet computers introduced in 2019 | Surface Pro 7 | [
"Technology"
] | 554 | [
"Crossover devices",
"2-in-1 PCs"
] |
61,945,249 | https://en.wikipedia.org/wiki/Sony%20Handheld%20Engine | The Sony Handheld Engine (or Sony HHE) was an ARM-based Application Processor, or SoC announced by Sony in July 2003. This mobile processor was specifically developed for the Sony CLIE series of PDAs, and was cutting-edge for the time, with a heavy focus on power-efficiency, and featuring numerous state-of-the-art features integrated into a single Application Processor IC.
The Sony Handheld Engine processor (model CXD2230GA) was first used on the Sony CLIÉ UX Series. This processor was also used on some subsequent CLIÉ models, specifically the TH55 and on the VZ90.
This processor was advertised as having additional mobile capabilities, such as dynamic speed scaling for power efficiency, hardware acceleration for MPEG video playback, a DSP for audio processing, a 2D graphics accelerator, as well as integrated camera, MemoryStick, and LCD interfaces. This highly integrated combination of capabilities were not found in other mobile CPU's until several years later. The processor offered DVFM (Dynamic Voltage and Frequency Management), combining both dynamic clock speed and dynamic voltage scaling power saving features together, and this was advertised as being the world's first commercial implementation of such a feature. This processor also featured a 123 MHz ARM926 core with 64 Mbit of integrated eDRAM, and was produced on a 180 nm lithography process by Sony Computer Entertainment in their Nagasaki Chip Fab.
Devices featuring the Sony HHE
Sony CLIÉ UX Series
Sony CLIÉ PEG-VZ90
Sony CLIÉ PEG-TH55
See also
XScale
References
ARM-based systems on chips
Sony semiconductors
System on a chip | Sony Handheld Engine | [
"Technology"
] | 337 | [
"Mobile computer stubs",
"Mobile technology stubs"
] |
61,945,578 | https://en.wikipedia.org/wiki/Anne%20Butler%20%28engineer%29 | Anne Butler CEng. FIEI served as president for Engineers Ireland in 2005. She was only the second woman to hold this position. Butler was a founding director of the Environmental Protection Agency in Ireland.
Biography
Anne Butler grew up in Kilkelly, County Mayo. She studied Civil Engineering in University College Galway in 1976. Butler went on to complete a MSc in Structural Engineering in 1977 and then a Diploma in Environmental Engineering in 1990 from Trinity College, Dublin. Butler has become a chartered Engineer. She went on to be President of the Institution of Engineers of Ireland. Butler was a founding Director of the Environmental Protection Agency (EPA) in Ireland and remained on its board for ten years. Butler is on the Board of the ESB Group and on the Governing Body of the Dublin Institute of Technology. Butler was awarded the TBD Alumni Award for her contribution to the field of "Engineering, IT and Mathematics". Butler is also a member of the Irish Academy of Engineering.
See also
Engineers Ireland
References
Living people
Year of birth missing (living people)
Alumni of the University of Galway
Alumni of Trinity College Dublin
Engineers from County Mayo
Environmental engineers
21st-century Irish women engineers
21st-century Irish engineers
20th-century Irish women engineers
20th-century Irish engineers | Anne Butler (engineer) | [
"Chemistry",
"Engineering"
] | 249 | [
"Environmental engineers",
"Environmental engineering"
] |
61,947,436 | https://en.wikipedia.org/wiki/Time%20in%20Antigua%20and%20Barbuda | Antigua and Barbuda Time (AST) is the official time in Antigua and Barbuda. It is four hours behind Coordinated Universal Time (UTC−04:00). Antigua and Barbuda has only one time zone and does not observe daylight saving time.
IANA time zone database
In the IANA time zone database Antigua and Barbuda has the following time zone:
America/Antigua (AG)
References
Time by country
Geography of Antigua and Barbuda | Time in Antigua and Barbuda | [
"Physics"
] | 98 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
61,947,697 | https://en.wikipedia.org/wiki/Yuri%20Tschinkel | Yuri Tschinkel (Юрий Чинкель, born 31 May 1964 in Moscow) is a Russian-German-American mathematician, specializing in algebraic geometry, automorphic forms and number theory.
Education and career
Tschinkel attended from 1979, the Erweiterte Oberschule Heinrich-Hertz-Gymnasium in East Berlin and passed there in 1983 the Abitur. He graduated with honors from Lomonosov Moscow State University in 1990 and received his doctorate in 1992 from the Massachusetts Institute of Technology with thesis Rational points on algebraic surfaces under the supervision of Yuri Manin and Michael Artin. From 1992 to 1995 Tschinkel was a junior fellow at Harvard University. In 1995 he became an assistant professor at the University of Illinois at Chicago (UIC) and from 1999 to 2003 he was an associate professor there. From 2003 to 2008 he was a professor at the University of Göttingen. He has been a professor at the Courant Institute of Mathematical Sciences of New York University since 2005 and, since 2012, director of the Simons Foundation's Department of Mathematics and Physics.
He has been a visiting scholar at the École Polytechnique, the Institut des hautes études scientifiques, the Max Planck Institute for Mathematics in Bonn, the Isaac Newton Institute at the University of Cambridge, Stanford University, Princeton University (1999 to 2003), Kyoto's Research Institute for Mathematical Sciences, and the University of Tokyo.
Tschinkel does research on rational points on algebraic varieties and other questions of arithmetic geometry. He is the author or co-author of over 110 research publications. He has been a co-editor of several anthologies and conference reports on arithmetic geometry, e.g., co-editor with William Duke of the Gauß–Dirichlet conference in Göttingen in 2005 and also co-editor with Yuri Zarhin of the Festschrift for his teacher Yuri Manin.
In 1995–1996 Tschinkel was a Leibniz Fellow of the European Union at the École normale supérieure in Paris, and in 2001–2002 he was Clay Mathematics Institute Fellow. In 2006, he was an Invited Speaker with talk Geometry over nonclosed fields at the International Congress of Mathematicians in Madrid. Tschinkel has German and American citizenships. He was elected a Fellow of the American Mathematical Society in 2012. In 2018 he was elected a member of the German Academy of Sciences Leopoldina.
Selected publications
as editor with Emmanuel Peyre: "Rational points on algebraic varieties", Birkhäuser 2001
as editor with Bjorn Poonen: Arithmetic of higher dimensional algebraic varieties , Birkhäuser 2004
as editor with Fedor Bogomolov: "Geometric methods in algebra and number theory", Birkhäuser 2005
as editor with Fedor Bogomolov: "Cohomological and geometric approaches to rationality problems: new perspectives", Birkhäuser 2009
as editor with William Duke: Analytic Number Theory – a tribute to Gauss and Dirichlet , American Mathematical Society 2007
as editor with Yuri Zarhin: Algebra, Arithmetic and Geometry – In Honor of Yuri Manin , Birkhäuser 2010
as editor with Wee-Teck Gan and Stephen Kudla: "Eisenstein Series and Applications", Birkhäuser 2008
External links
(link to online publications, including books edited)
(link to online publications, including books edited)
References
1964 births
Living people
Mathematicians from Moscow
Moscow State University alumni
Massachusetts Institute of Technology School of Science alumni
Harvard University people
University of Illinois Chicago faculty
Academic staff of the University of Göttingen
Courant Institute of Mathematical Sciences faculty
Algebraic geometers
Number theorists
Fellows of the American Mathematical Society
20th-century American mathematicians
21st-century American mathematicians
Members of the German National Academy of Sciences Leopoldina | Yuri Tschinkel | [
"Mathematics"
] | 767 | [
"Number theorists",
"Number theory"
] |
61,948,018 | https://en.wikipedia.org/wiki/Cercophora%20areolata | Cercophora areolata is a member of the Ascomycota division, and is grouped into the Lasiosphaeriaceae family based on morphology. C. areolata is a coprophilous fungus that has been most recently isolated from porcupine dung. Defining features of C. areolata include: 1) ovoid-conical, glabrous ascomata, 2) black, carbonaceous, areolate peridium and 3) clavate-shaped, single-walled asci. From studies on C. areolata, this fungus produces multiple antifungal compounds, which inhibit other competitor fungi.
History and taxonomy
Nils Lundqvist, a Swedish mycologist, first discovered Cercophora areolata in 1891, and the description of C. areolata was not published until 1972 in the book Nordic Sordariaceae s. lat, written by Lundqvist himself. Lundqvist first stumbled upon the holotype of C. areolata in Aspvik, Gustavavsberg, Uppland, Sweden, on the dung of Equus caballus. The holotype was first named Hypoxylon coprophila,; However, there is little information regarding C. areolata with this synonym. Based on morphology and molecular data, C. areolata is grouped into the Lasiosphaeriaceae taxonomic clade alongside several members of the Arnium genus. The ascomata of these Arnium species have glabrous or have flexous hairs, similar to the perithecia of C. areolata. A subclade within this clade is supported by C. areolata, Arnium mendax and Arnium inaequilaterale.
Morphology
Cercophora areolata produces perithecia, also known as ascomata, which are fruiting bodies with necks. The perithecia of C. areolata are described as ovoid to conical, aggregated, non-stromatic, ostiolate (have small pores for the discharge of spores), and they have cone-shaped, ridged necks. Perithecia may be glabrous, enveloped with flexuous, brown, septate thick hairs or with short, hyaline (colourless), cylindrical, septate hairs. The perithecia are also characterized as superficial, in which the perithecia appear along the stalk, similar to the phenotype of the Ophiocordyceps species.
The peridium, the protective covering of the perithecium, appears pseudoparenchymatous, meaning it resembles the parenchyma of plant tissue, but consists of fungal hyphae woven together. The peridium is further described as black-brown, opaque, carbonaceous, has 3 layers and is areolate. C. areolata has the most distinct areolate pattern, in which the peridium cracks into broad polygone plates along edges of hyaline cells. The peridial cells in the outer layer resemble the shape of a prism, are thick-walled, and are in a radial arrangement in each polygone. The peridial cells in the middle layer appear flattened. Perithecial contents are yellow, similar to Lasiosphaeria ovina and some Cercophora species. However, L. ovina and other Cercophora species present contrasting peridium, which are more membranaceous and ochraceous (ochre-coloured) to light brown. When specimens are desiccated, the yellow colour dissipates. The areolate peridium is similar to Lasiosphaeria dichroospora, Bombardia manihotis, Sordaria striata, Cercophora coprogena, C. californica, Zopfiella, and Cephalotheca.
As a member of the Ascomycota, C. areolata has asci, sacs that grow in the ascomata and house the developing sexual spores. The asci contain about 8 ascospores, are clavate-shaped (thicker at the apex) and are unitunicate, meaning they are single-walled. The asci become costate (ribbed) after bursting of the perithecium, a process known as dehiscence. The ascus tip possesses a thick, double-apical ring and lacks a sub-apical globulus. Paraphyses, erect filament-like structures, appear longer than asci. The ascospores contained within the asci are arranged in series of 2–3. In immature asci, the spores are initially hyaline (colourless), single-celled, cylindrical, vermiform (worm-like), slightly sigmoid, and smooth. Sticky gelatinous tails called "caudae" are attached at both ends of each ascospore.
Growth and Habitat
Cercophora areolata is a fimicolous or coprophilous fungus, a fungus that preferably colonizes the dung of herbivores. Animal dung serves as a nutrient-rich source for coprophilous fungi, providing high content of nitrogen and carbohydrate. C. areolata has been isolated from porcupine dung.
Antifungal and cytotoxic compounds
Many fimicolous fungi exhibit interspecies competition, or fungal antagonism, which entails the generation of inhibiting chemicals targeting other species. Thus, Cercophora areolata produces many secondary metabolites such as Cercophorin A, Cercophorin B, Cercophorin C, allowing for C. areolata to display antibacterial and antifungal activity. C. areolata also produces decarboxycitrinone, 4-acetyl-8-hydroxy-6-methoxy-5-methylisocoumarin and roridin E.
Cercophorins A-C are 8-hydroxyisocoumarin derivatives. Cercophorin A is a white, solid substance, whereas cercophorin B and C are yellow, solid substances. Cercophorins A-C demonstrate antifungal and cytotoxic activity against Sordaria fimicola and Ascobolus furfuraceus. Cercophorins A-C act to impede the growth of these early successional coprophilous fungi, which appear much earlier on dung and have more rapid metabolisms. From standard disk assays, Cercophorin A generated zones of inhibition of about 26 and 16mm when tested on Bacillus subtilis and Staphylococcus aureus, respectively. Thus, Cercophorin A is most potent against B. subtilis and S. aureus.
Decarboxycitronine displayed antifungal activity against S. fimicola and A. furfuraceus, as treatment resulted in 100% reduction in radial growth. Roridin E, a known trichothecene mycotoxin, also demonstrated antifungal activity, as it caused 100% reduction in growth of S. fimicola and A. furfuraceus. Roridin E executes anti-Candida activity.
Cercophorins A-C are novel antifungal agents, as there a no known analogs in other species. Decarboxycitronine is similar to a product from Penicillium citrinum, decarboxydihydrocitrinone. 4-acetyl-8-hydroxy-6-methoxy-5-methylisocoumarin is derived from another antifungal metabolite in Aspergillus viridinutans. All of these secondary metabolites are the first natural antifungal agents to be described from the genus Cercophora.
References
Lasiosphaeriaceae
Fungus species | Cercophora areolata | [
"Biology"
] | 1,672 | [
"Fungi",
"Fungus species"
] |
44,320,407 | https://en.wikipedia.org/wiki/Mars%20Oxygen%20ISRU%20Experiment | The Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) was a technology demonstration on the NASA Mars 2020 rover Perseverance investigating the production of oxygen on Mars. On April 20, 2021, MOXIE produced oxygen from carbon dioxide in the Martian atmosphere by using solid oxide electrolysis. This was the first experimental extraction of a natural resource from another planet for human use. The technology may be scaled up for use in a human mission to the planet to provide breathable oxygen, oxidizer, and propellant; water may also be produced by combining the produced oxygen with hydrogen.
The experiment was a collaboration between the Massachusetts Institute of Technology, the Haystack Observatory, the NASA/Caltech Jet Propulsion Laboratory, with OxEon Energy.
Objective
MOXIE's objective was to produce oxygen of at least 98% purity at a rate of and to do this at least ten times, so the device can be tested in a range of times of the day, including at night, and in most environmental conditions, including during a dust storm.
Development
MOXIE builds upon an earlier experiment, the Mars In-situ propellant production Precursor (MIP), which was designed and built to fly on the Mars Surveyor 2001 Lander mission. MIP was intended to demonstrate In-Situ Propellant Production (ISPP) on a laboratory scale using electrolysis of carbon dioxide to produce oxygen. The MIP flight demonstration was postponed when the Mars Surveyor 2001 lander mission was cancelled after the Mars Polar Lander mission failed.
The Principal Investigator (PI) of MOXIE was Michael Hecht from the Haystack Observatory at Massachusetts Institute of Technology (MIT). The deputy PI was former NASA astronaut Jeffrey Hoffman from the Department of Aeronautics and Astronautics at MIT. The project manager was Jeff Mellstrom from the NASA/Caltech Jet Propulsion Laboratory (JPL). Along with MIT and JPL, major contributors are OxEon Energy (previously Ceramatec, Inc.) and Air Squared. Other contributors include Imperial College London, Space Exploration Instruments LLC, Destiny Space Systems LLC, the Niels Bohr Institute at the University of Copenhagen, Arizona State University, and the Technical University of Denmark.
Principle
MOXIE acquires, compresses, and heats Martian atmospheric gases using a HEPA filter, scroll compressor, and heaters alongside insulation, then splits the carbon dioxide () molecules into oxygen (O) and carbon monoxide (CO) using solid oxide electrolysis, where the O atoms combine to form gaseous oxygen ().
The conversion process requires a temperature of approximately . A solid oxide electrolysis cell works on the principle that, at elevated temperatures, certain ceramic oxides, such as yttria-stabilized zirconia (YSZ) and doped ceria, become oxide ion (O2–) conductors. A thin nonporous disk of YSZ (solid electrolyte) is sandwiched between two porous electrodes. diffuses through the porous electrode (cathode) and reaches the vicinity of the electrode-electrolyte boundary. Through a combination of thermal dissociation and electrocatalysis, an oxygen atom is liberated from the molecule and picks up two electrons from the cathode to become an oxide ion (O2–). Via oxygen ion vacancies in the crystal lattice of the electrolyte, the oxygen ion is transported to the electrolyte–anode interface due to the applied DC potential. At this interface, the oxygen ion transfers its charge to the anode, combines with another oxygen atom to form oxygen (), and diffuses out of the anode.
The net reaction was thus + . Inert gases such as nitrogen gas () and argon (Ar) are not separated from the feed, but returned to the atmosphere with the carbon monoxide (CO) and unused .
Mars experiment
Oxygen production was first achieved on April 20, 2021, in Jezero Crater, producing of oxygen, equivalent to what an astronaut on Mars would need to breathe for roughly 10 minutes. MOXIE was designed to safely generate up to of oxygen, with theoretical production limited to of oxygen due to the limited capacity of the 4 ampere flight power supply. The oxygen produced was analyzed, and then released back into the atmosphere.
MOXIE was used to isolate oxygen a further nine more times over the course of approximately two Earth years, or one Martian year, in three stages; the first stage will further investigate the oxygen production, the second to test the instrument in a variety of times of day, seasons, and atmospheric conditions, and the third to produce oxygen at different temperatures, and alter the mode of operation to investigate differences in production.
On April 21, 2021, Jim Reuter, the Associate Administrator for STMD explained that the experiment was functioning with results having many uses, stating: "This is a critical first step at converting carbon dioxide to oxygen on Mars. MOXIE has more work to do, but the results from this technology demonstration are full of promise as we move toward our goal of one day seeing humans on Mars. Oxygen isn’t just the stuff we breathe. Rocket propellant depends on oxygen, and future explorers will depend on producing propellant on Mars to make the trip home."
MOXIE had generated a total of of oxygen – about what a small dog breathes in 10 hours. At its most efficient, MOXIE was able to produce of oxygen – twice as much as NASA’s original goals for the instrument – at 98% purity or better. On its 16th and final run, on August 7, 2023, the instrument made of oxygen. MOXIE successfully completed all of its technical requirements and was operated at a variety of conditions throughout a full Mars year, allowing the instrument’s developers to learn a great deal about the technology.
Implications
NASA states that if MOXIE worked efficiently, they could land an approximately 200-times larger, MOXIE-based instrument on the planet, along with a power plant capable of generating . Over the course of approximately one Earth year, this system would produce oxygen at a rate of at least in support of a human mission sometime in the 2030s. The stored oxygen could be used for life support, but the primary need is for an oxidizer for a Mars ascent vehicle. It was projected for example, in a mission of four astronauts on Martian surface for a year, only about 1 metric ton of oxygen would be used for life support for the entire year, compared to about 25 metric tons of oxygen for propulsion off the surface of Mars for the return mission. The CO, a byproduct of the reaction, may be collected and used as a low-grade fuel or reacted with water to form methane () for use as a primary fuel. As an alternative use, an oxygen generation system could fill a small oxygen tank as fuel-oxidiser to support a sample return mission. The oxygen could also be combined with hydrogen to form water.
Technical specifications
Data from NASA (MARS 2020 Mission Perseverance Rover), Ceramatec and OxEon Energy, NASA Jet Propulsion Laboratory.
Main job: To produce oxygen from the Martian carbon dioxide atmosphere.
Location: Inside the rover (front, right side)
Mass: 17.1 kilograms
Weight: on Earth, on Mars
Power: 300 watts
Volume:
Oxygen production rate: Up to per hour
Operation time: Approximately one hour of oxygen () production per experiment, which will be scheduled intermittently over the duration of the mission.
MOXIE: Operational Design Drive (SOXE):
Gas flow: Internally manifolded for purity and dP
Feed: Dry in a range of 30–80 g/hr
Product: 99.6% pure , internal manifolding
Structural: Robust to survive launch, EDL shock and vibe, compression load requirements
Power: Highly constrained
Mass: 1 kg max
Volume: Rigidly constrained
Operation: 20+ 120 minute cycles
Heating ramps: 90 minutes (c. 515 °C/hour) from ambient(potentially −40 °C) to 800 °C.
Heat application: Heaters on endplates only
MOXIE: Materials Design Drivers:
Interconnects (IC): Powder metallurgy (CFY, Plansee)
Seals: Glass seals
Current busbars: Brazed rod / welded wire
Feed manifolds: Inlet tube/internal manifold purity
Anode electrode: Perovskite
Cathode electrode: Modified proprietary Cermet
Electrolyte: Scandia-stabilized zirconia (ScSZ)
MOXIE: Cell design:
Number of cells: 10 (arranged in two stacks of 5 cells each)
Oxygen production: 10 grams per hour (>1g/hr. per cell)
Each cell consists of:
Electrolyte (yttria-stabilized zirconia (YSZ))
Cathode
Anode
Connecting cells:
High chromium alloy (matched CTE to ceramic electrolyte)
Approximately
Contains manifolding for gas streams
MOXIE: Gas delivery system (scroll compressor):
Scroll pump compression rate: Up to approximately 1 bar
Scroll pump RPM: Low-speed (2000–4000 RPM)
Performance: Inlet gas: 83 g/hr, P = 7 Torr, T = 20 °C, Pin = 120 W, Mass: c. 2 kg
MOXIE: Targets:
Operational Cycles: The primary mission requirements call for the capability to operate a total of 20 cycles:
10 cycles preflight
10+ cycles on Mars
Qualification and verification testing: It involves 60 full operational cycles for proof of extensibility, which is three times the number of cycles planned for the primary mission.
Oxygen purity: 99.6%+ at end of life
Temperature capability: Capable to operate at −65 °C proof temperature
Compression, shock, and vibe requirements:
Withstand 8 kN compressive force
Withstand (PF) + 3 dB levels for flight shock and vibe requirements
References
External links
Colonization of Mars
Electrochemical cells
Mars 2020 instruments
Oxygen
Space science experiments
Technology demonstrations | Mars Oxygen ISRU Experiment | [
"Chemistry"
] | 2,012 | [
"Electrochemistry",
"Electrochemical cells"
] |
44,321,440 | https://en.wikipedia.org/wiki/Supersonic%20flow%20over%20a%20flat%20plate | Supersonic flow over a flat plate is a classical fluid dynamics problem. There is no exact solution to it.
Physics
When a fluid flow at the speed of sound over a thin sharp flat plate over the leading edge at low incident angle at low Reynolds Number. Then a laminar boundary layer will be developed at the leading edge of the plate. And as there are viscous boundary layer, the plate will have a fictitious boundary layer so that a curved induced shock wave will be generated at the leading edge of the plate.
The shock layer is the region between the plate surface and the boundary layer. This shock layer be further subdivided into layer of viscid and inviscid flow, according to the values of Mach number, Reynolds Number and Surface Temperature. However, if the entire layer is viscous, it is called as merged shock layer.
Solution to the Problem
This Fluid dynamics problem can be solved by different Numerical Methods. However, to solve it with Numerical Methods several assumptions have to be considered. And as a result shock layer properties and shock location is determined. Results vary with one or more than one of viscosity of the fluid, Mach number and angle of incidence changes. Generally for large angles of incidences, the variation of Reynold's Number has significant effects on the change of the flow variables, whereas the viscous effects are dominant on the upper surface of the plate as well as behind the trailing edge of the plate.
Different experimenters get different result as per the assumptions they have made to solve the problem.
The primary method which is generally used to this problem:
Explicit Finite Difference Approach
This method involves using time-dependent Navier-Stokes equation which is advantageous because of its inherent ability to evolve to the correct steady state solution.
The continuity, momentum and energy equations and some other situational equations are needed to solve the problem. MacCormack's time marching technique is applied and then using Taylor series expansion the flow field variables are advanced at each grid point. Then, initial boundary conditions are applied and solving equations will converge to approximated results.
These equations can be solved by using different algorithms to get better and efficient results with minimum errors.
References
On boundary-layer flow past two-dimensional obstacles By F. T. SMITH, Department of Mathematics, Imperial College, London SW7 2BZ P. W. M. BRIGHTON,? P. S. JACKSONS AND J. c . R. HUNT http://www.cpom.org/people/jcrh/jfm-113
A numerical study of the viscous supersonic flow past a flat plate at large angles of incidence By D. Drikakis and F. Durst Lehrstuhlfiir Stromungsmechanik, Universitat Erlangen-Niirnberg, Cauerstrasse. 4, D-91058 Erlangen, Germany https://www.deepdive.com/search?author=Durst%2C+F.&numPerPage=25
Receptivity of a supersonic boundary layer over a flat plate. Part 1. Wave structures and interactions By YANBAO MA AND XIAOLIN ZHONG Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA 90095 USA http://www.journals.cambridge.org/article_S0022112003004786
Computational Fluid Dynamics The Basics with Applications By John D. Anderson, Jr.
Aerodynamics
Fluid dynamics | Supersonic flow over a flat plate | [
"Chemistry",
"Engineering"
] | 708 | [
"Chemical engineering",
"Aerodynamics",
"Aerospace engineering",
"Piping",
"Fluid dynamics"
] |
44,322,533 | https://en.wikipedia.org/wiki/Metal-coded%20affinity%20tag | Metal-coded affinity tag is a method used for quantitative proteomics by mass spectrometry that uses a metal chelate complex 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) coupled to different lanthanide ions. The metal complexes attach to the cysteine residues of proteins in a sample.
Proteomic analysis
For bottom-up proteomics, the proteins can be separated by two-dimensional gel electrophoresis and analyzed by matrix-assisted laser desorption/ionization (MALDI) or electrospray ionization mass spectrometry for relative quantification or by inductively coupled plasma mass spectrometry for absolute quantification. For top-down proteomics, the undigested labeled proteins are analyzed.
See also
Mass cytometry
References
Mass spectrometry
Proteomics | Metal-coded affinity tag | [
"Physics",
"Chemistry"
] | 197 | [
"Spectrum (physical sciences)",
"Instrumental analysis",
"Mass",
"Mass spectrometry",
"Analytical chemistry stubs",
"Matter"
] |
44,322,919 | https://en.wikipedia.org/wiki/HL%20Tauri | HL Tauri (abbreviated HL Tau) is a young T Tauri star in the constellation Taurus, approximately from Earth in the Taurus Molecular Cloud. The luminosity and effective temperature of imply that its age is less than 100,000 years. At apparent magnitude 15.1, it is too faint to be seen with the unaided eye. It is surrounded by a protoplanetary disk marked by dark bands visible in submillimeter radiation that may indicate a number of planets in the process of formation. It is accompanied by the Herbig–Haro object , a jet of gas emitted along the rotational axis of the disk that is colliding with nearby interstellar dust and gas.
Protoplanetary disk
Indications of a protoplanetary disk were first presented in 1975 with infrared spectral observations in wavelengths between 2 and 4 microns, which were made possible by the recent invention of the indium antimonide photovoltaic detector. Of 29 very young stars examined, only showed a strong absorption feature centered on the expected 3.07 micron absorption of ice particles, which authors attributed to the ν1, ν3, and 2ν2 vibrational frequencies of the O–H bond. A 1982 survey identified as one of the most highly polarized stars known, along with DG Tauri and V536 Aquilae.
A gas disk was discovered by interferometric observation of carbon monoxide (CO) emissions in 1986. Based on observation data in 1985 and 1986 from the Millimeter Wave Interferometer of the Owens Valley Radio Observatory, the circumstellar disk was estimated to have a mass between and , with a best fit of , and a radius of about 200 AU. The temperature of the gas and grains of the disk are probably of the order of a few tens of kelvins. The gas was found to be bound to and in Keplerian rotation around a star with a mass of about . Bipolar outflow of molecules such as carbon monoxide (CO) and diatomic hydrogen (H2) have been observed. The element iron has also been noted in the outflow in its Fe(II) oxidation state, also called Fe2+ or ferrous iron.
An image of the protoplanetary disk made at submillimeter wavelengths by the Atacama Large Millimeter/submillimeter Array (ALMA) was made public in 2014, showing a series of concentric bright rings separated by gaps. The disk appeared much more evolved than would have been expected from the age of the system, which suggests that the planetary formation process may be faster than previously thought. ALMA's Catherine Vlahakis said, "When we first saw this image we were astounded at the spectacular level of detail. HL Tauri is no more than a million years old, yet already its disc appears to be full of forming planets. This one image alone will revolutionize theories of planet formation."
Stephens et al. (2014) suggest that the faster accretion rate might be due to the complex magnetic field of the protoplanetary disk.
In 2024, water was found within the protoplanetary disk using the Atacama Large Millimeter Array (ALMA), containing 3.7 Earth oceans worth of water vapour.
Gallery
References
External links
K-type stars
Tauri, HL
T Tauri stars
Taurus (constellation) | HL Tauri | [
"Astronomy"
] | 688 | [
"Taurus (constellation)",
"Constellations"
] |
44,323,655 | https://en.wikipedia.org/wiki/Climate%20as%20complex%20networks | The field of complex networks has emerged as an important area of science to generate novel insights into nature of complex systems The application of network theory to climate science is a young and emerging field. To identify and analyze patterns in global climate, scientists model climate data as complex networks.
Unlike most real-world networks where nodes and edges are well defined, in climate networks, nodes are identified as the sites in a spatial grid of the underlying global climate data set, which can be represented at various resolutions. Two nodes are connected by an edge depending on the degree of statistical similarity (that may be related to dependence) between the corresponding pairs of time-series taken from climate records.
The climate network approach enables novel insights into the dynamics of the climate system over different spatial and temporal scales.
Construction of climate networks
Depending upon the choice of nodes and/or edges, climate networks may take many different forms, shapes, sizes and complexities.
Tsonis et al. introduced the field of complex networks to climate. In their model, the nodes for the network were constituted by a single variable (500 hPa) from NCEP/NCAR Reanalysis datasets. In order to estimate the edges between nodes, correlation coefficient at zero time lag between all possible pairs of nodes were estimated. A pair of nodes was considered to be connected, if their correlation coefficient is above a threshold of 0.5.
Steinhaeuser and team introduced the novel technique of multivariate networks in climate by constructing networks from several climate variables separately and capture their interaction in multivariate predictive model. It was demonstrated in their studies that in context of climate, extracting predictors based on cluster attributes yield informative precursors to improve predictive skills.
Kawale et al. presented a graph based approach to find dipoles in pressure data. Given the importance of teleconnection, this methodology has potential to provide significant insights.
Imme et al. introduced a new type of network construction in climate based on temporal probabilistic graphical model, which provides an alternative viewpoint by focusing on information flow within network over time.
Agarwal et al. proposed advanced linear and nonlinear methods to construct and investigate climate networks at different timescales. Climate networks constructed using SST datasets at different timescale averred that multi-scale analysis of climatic processes holds the promise of better understanding the system dynamics that may be missed when processes are analyzed at one timescale only
Applications of climate networks
Climate networks enable insights into the dynamics of climate system over many spatial scales. The local degree centrality and related measures have been used to identify super-nodes and to associate them to known dynamical interrelations in the atmosphere, called teleconnection patterns. It was observed that climate networks possess “small world” properties owing to the long-range spatial connections.
Steinhaeuser et al. applied complex networks to explore the multivariate and multi-scale dependence in climate data. Findings of the group suggested a close similarity of observed dependence patterns in multiple variables over multiple time and spatial scales.
Tsonis and Roeber investigated the coupling architecture of the climate network. It was found that the overall network emerges from intertwined subnetworks. One subnetwork is operating at higher altitudes and other is operating in the tropics, while the equatorial subnetwork acts as an agent linking the 2 hemispheres . Though, both networks possess Small World Property, the 2 subnetworks are significantly different from each other in terms of network properties like degree distribution.
Donges et al. applied climate networks for physics and nonlinear dynamical interpretations in climate. The team used measure of node centrality, betweenness centrality (BC) to demonstrate the wave-like structures in the BC fields of climate networks constructed from monthly averaged reanalysis and atmosphere-ocean coupled general circulation model (AOGCM) surface air temperature (SAT) data.
Teleconnection path
Teleconnections are spatial patterns in the atmosphere that link weather and climate anomalies over large distances across the globe. Teleconnections have the characteristics that they are persistent, lasting for 1 to 2 weeks, and often much longer, and they are recurrent, as similar patterns tend to occur repeatedly. The presence of teleconnections is associated with changes in temperature, wind, precipitation, atmospheric variables of greatest societal interest.
Computational issues and challenges
There are numerous computational challenges that arise at various stages of the network construction and analysis process in field of climate networks:
Calculating the pair-wise correlations between all grid points is a non-trivial task.
Computational demands of network construction, which depends upon the resolution of spatial grid.
Generation of predictive models from the data poses additional challenges.
Inclusion of lag and lead effects over space and time is a non-trivial task.
See also
Community structure
Network theory
Network science
Teleconnection
Climatology
References
Network theory
Climatology | Climate as complex networks | [
"Mathematics"
] | 990 | [
"Network theory",
"Mathematical relations",
"Graph theory"
] |
44,323,974 | https://en.wikipedia.org/wiki/Geoethics | Geoethics is the branch of ethics which relates to the interaction of human activity with our physical world in general, and with the practice of the Earth sciences in particular. It may also have relevance to planetary sciences. It is described as an emerging scientific and philosophical discipline, consisted of research and reflection on the values that serve as the bases of behaviors and practices wherever human activities interact with the Earth system. Moreover, geoethics promotes the ethical and social roles of geoscientists in conducting scientific and technological research and practice.
For these reasons, geoethics pursues recognition of humankind's duties and responsibility towards the Earth system. A more specialized use emerged as the term came to deal with the ethical, social, and cultural implications of the behavior and professional activities of geoscientists. Some scholars also cited that it provides a point of intersection for geosciences, sociology, economics and philosophy.
The International Association for Promoting Geoethics, included in the international geoethics infrastructure together with the IUGS Commission on Geoethics and the CIPSH Chair on Geoethics, is the leading organization that is carrying out studies to develop the geoethical thought and to promote geoethics outcomes worldwide.
References
Environmental ethics | Geoethics | [
"Environmental_science"
] | 252 | [
"Environmental ethics"
] |
44,325,436 | https://en.wikipedia.org/wiki/Petroleomics | Petroleomics is the identification of the totality of the constituents of naturally occurring petroleum and crude oil using high resolution mass spectrometry. In addition to mass determination, petroleomic analysis sorts the chemical compounds into heteroatom class (nitrogen, oxygen and sulfur), type (degree of unsaturation, and carbon number). The name is a combination of petroleum and -omics (collective chemical characterization and quantification).
History
Mass spectrometry characterization of petroleum has been performed since the first commercial mass spectrometers were introduced in the 1940s. Early mass spectrometry was limited to relatively low molecular weight nonpolar species accessed mainly by electron ionization with mass analysis with sector mass spectrometers. By the end of the 20th century, separations combined with mass spectrometric techniques such as gas chromatography-mass spectrometry and liquid chromatography mass spectrometry have characterizated petroleum distillates such as gasoline, diesel, and gas oil.
The first petroleum analysis with electrospray ionization was demonstrated in 2000 by Zhan and Fenn, who studied the polar species in petroleum distillates with low-resolution MS. Electrospray ionization was coupled with high-resolution FT-ICR by Marshall and coworkers. To date, many studies on petroleomic analysis of crude oils have been published. Most work has been done by the group of Marshall at the National High Magnetic Field Laboratory (NHMFL) and Florida State University.
Ionization methods
Ionization of nonpolar petroleum components can be achieved by field desorption ionization and atmospheric pressure photoionization (APPI). field desorption FT-ICR MS has enabled the identification of a large number of nonpolar components in crude oils that are not accessible by electrospray, such as benzo- and dibenzothiophenes, furans, cycloalkanes, and polycyclic aromatic hydrocarbons (PAHs). A drawback of field desorption is that it is slow, mainly due to the need of ramping the current to the emitter in order to volatilize and ionize molecules. APPI can ionize both polar and nonpolar species, and an APPI spectrum can be generated in just a few seconds. However, APPI ionizes a broad range of compound classes and produces both protonated and molecular ion peaks, resulting in a complex mass spectrum.
Kendrick analysis
High mass resolution data analysis is usually undertaken by converting the mass spectra to the Kendrick mass scale, in which the mass of a methylene unit is set to exactly 14 (CH2 = 14.0000 instead of 14.01565 daltons). This rescaling of the data aids in the identification of homologous series according to alkylation, class (number of heteroatoms), and type (double bond equivalent, DBE, also called rings plus double bonds or degree of unsaturation). The scaled data is then used to obtain the Kendrick mass defect (KMD), which is given by
where the nominal Kendrick is the Kendrick mass rounded to the nearest integer. Double bond equivalent (DBE) is calculated according to
where C = number of carbons, H = number of hydrogens, X= number of halogens and N = number of nitrogens. O
Compounds with the same DBE have the same mass defect. Therefore, Kendrick normalization yields a set of series with identical mass defect that appear as horizontal rows in a plot of DBE versus Kendrick mass. The data can also be plotted as a 3D heat-map to indicate the relative intensity of the mass spectral peaks. From the Kendrick plot, the species with peaks in the mass spectrum can be sorted into compound classes by the number of nitrogen, oxygen and sulfur heteroatoms.
The data can also be represented with a Van Krevelen diagram.
See also
Orbitrap
References
External links
Mass spectrometry
Petroleum | Petroleomics | [
"Physics",
"Chemistry"
] | 830 | [
"Spectrum (physical sciences)",
"Instrumental analysis",
"Mass",
"Petroleum",
"Mass spectrometry",
"Chemical mixtures",
"Matter"
] |
44,326,004 | https://en.wikipedia.org/wiki/Thermoplastic%20road%20marking%20paint | Thermoplastic road marking paint, also called hot melt marking paint, is a kind of powder paint. When applied as road surface markings, a hot melt kettle is used to heat it to to melt the powder, after which it is sprayed on the road surface. After cooling, the paint forms a thick polymer layer, which is wear-resistant, bright, and reflective. In recent years, practical applications tests have proved that the marking lines lack surface roughness and can easily cause wheel slip, resulting in a traffic accident in snow and rainy weather. Therefore, some countries once restricted the use of this paint or demand the use of anti-skid particles. In order to increase the antiskid performance of the line, thermoplastic paint has added reflective glass beads and other coarse fillers.
Thermoplastic can be used very effectively for large anti-skid areas on roads and pedestrian walkways by adding glass beads. It can be produced in any colour and is suitable for car parks, factory walkways, and many other areas. It hardens quickly and can be driven over after just a few minutes.
Components
Thermoplastic marking paint consists of synthetic (polymeric or non-polymeric) resin, glass beads, pigments, fillers (fine like calcium carbonate and coarse like sand), packing materials, additives, etc.
Synthetic resin has thermoplasticity, make the hot melt coating fast-dry and strongly adhesive to the road surface. Non-polymeric resins, based on colophony, are also widely used.
Additives in the paint can increase the plasticity of the coating, and make it resistant to subsidence, pollution and color fading.
Pigments: the common colours of road lines are yellow and white. White pigment is titanium dioxide. Occasionally zinc oxide can be used, but it is less effective due to low refractive index. For yellow thermoplastics, organic pigments (like Pigment Yellow 65, 74 or 83) are mostly used; lead-containing pigments are obsolete and banned in essentially all developed countries. Thermoplastic road markings can also be formulated in other colours.
Packing materials, as filling added into the paint, ensure mechanical strength, wear resistance, and color of paint coating. The particle size will affect liquidity and precipitation, as well as the surface processing.
Glass microspheres are added in order to improve the identification of lines at night, to improve the brightness and durability of the marking. Glass beads, usually 0.1-1.4 mm in diameter, are colourless and transparent; they reflect light from vehicle's headlights back toward the driver and foremost protect the road marking from abrasion.
Matched machines
A road marking machine is a machine specially used to mark different traffic lines on road surface, and some can remark on old lines directly. It can screed, extrude, or spray processed road paint onto the road surface to form durable coating lines. A hot melt kettle is used for continuously heating, melting, and stirring thermoplastic marking paints, preparing molten paints for the thermoplastic machine, especially for long-distance road-line-marking work. The molten paint quality can affect the line quality greatly.
Microplastic pollution
Thermoplastic paints, when used as road markings, are a source of microplastic pollution. Abrasive wear of road marking paint resins has been claimed to be responsible for 7% of all microplastic pollution, with estimates ranging from 0.7% to 19%.
See also
Pedestrian crossing
Road surface marking
Zebra crossing
References
Paints
Road surface markings | Thermoplastic road marking paint | [
"Chemistry"
] | 741 | [
"Paints",
"Coatings"
] |
44,327,815 | https://en.wikipedia.org/wiki/Nokia%206150 | The Nokia 6150 was a mobile phone released in 1998. It was an enhanced version of the Nokia 6110 - 6130: it could support both 900 MHz and 1800-1900 MHz GSM bands. The extra hardware required for dual-band capability (something uncommon for the era as transceivers were single-band initially) made the top side thicker than the 6110. The phone was used in the Mercedes-Benz S-Class (W220) (1998-2006 model), where it was held in a cradle and connected to the car's integrated car phone and media system called COMAND.
References
Mobile phones introduced in 1998
6150
Mobile phones with infrared transmitter | Nokia 6150 | [
"Technology"
] | 140 | [
"Mobile technology stubs",
"Mobile phone stubs"
] |
44,328,955 | https://en.wikipedia.org/wiki/Churn%20turbulent%20flow | Churn turbulent flow is a two-phase gas/liquid flow regime characterized by a highly-agitated flow where gas bubbles are sufficient in numbers to both interact with each other and, while interacting, coalesce to form larger distorted bubbles with unique shapes and behaviors in the system. This flow regime is created when there is a large gas fraction in a system with a high gas and low liquid velocity. It is an important flow regime to understand and model because of its predictive value in nuclear reactor vessel boiling flow.
Occurrence
A flow in which the number of bubbles is low is called ideally-separated bubble flow. The bubbles don’t interact with each other. As the number of bubbles increase they start colliding each other. A situation then arises where they tend to coalesce to form cap bubbles, and the new flow pattern formed is called churn turbulent flow. The bubbles occurring in such a flow can be classified in small, large, and distorted bubbles. The small bubbles are generally spherical or elliptical and are encountered in a major concentration in the wake of large and distorted bubbles and close to the walls. Large, ellipsoidal or cap bubbles can be found in the core region of the flow as well as the distorted bubbles with a highly deformed interface.
Churn turbulent flow is commonly encountered in industrial applications. A typical example is boiling flow in nuclear reactors.
Numerical simulation of bubble column flows in churn turbulent regime
Numerical simulations of cylindrical bubble columns operating in the churn-turbulent regime have been carried out using an Euler–Euler approach incorporated with the RNG k–ε model for liquid turbulence. Several approaches have been carried out, including single-sized bubble modeling, double-sized bubble modeling, and the multiple sizes group modeling (MUSIG).
Breakup mass conserved formulations and coalescence rates mass conserved formulation was used in the computation of bubble size distributions. For single size modelling the Schiller–Naumann drag force was used, and for the modelling of MUSIG the Ishii–Zuber drag force was used. An empirical drag formulation was used for the double size bubble model. The simulation results of time-averaged axial velocity and gas holdup obtained with the three models were compared with reported experimental data in the resulting literature. After the comparison of all the three results it gets very clear that only MUSIG models with some lift force can replicate the measured radial distribution of gas holdup in the fully developed flow regime. The inhomogeneous MUSIG model gives a little better result than other models in the prediction of axial liquid velocity. For all the simulations the RNG k–ε model was used, and the results showed that this version of k–ε model did yield comparatively high rate of turbulence dissipation and high bubble breakup and, hence, a rational bubble size distribution formed. Here the ad hoc manipulation of the breakup rates was ignored. Mutual effects of drag force, mean bubble sizes, and turbulence characteristics profound from the simulation results. A decrease in the relative velocity between two phases is encounters due to an increase in the drag force, and this could result in decrease in k and ε. Low breakup rates results a large Sauter diameter which was directly connected to the dissipation rates of turbulence. Drag force is directly influenced by the change of Sauter diameter.
References
Montoya, G.; Liao, Y.; Lucas, D.; Krepper, E. "Analysis and Applications of a Two-Fluid Multi-Field Hydrodynamic Model for Churn-Turbulent Flows", 21st International Conference on Nuclear Engineering – ICONE 21. China (2013)
Montoya, G.; Baglietto, E.; Lucas, D.; Krepper, E. "A Generalized Multi-Field Two-Fluid Approach for Treatment of Multi-Scale Interfacial Structures in High Void-Fraction Regimes", MIT Energy Night 2013. Cambridge, Massachusetts, USA (2013)
•Montoya, G.; Lucas, D.; Krepper, E.; Hänsch, S.; Baglietto, E.
Analysis and Applications of a Generalized Multi-Field Two-Fluid Approach for Treatment of Multi-Scale Interfacial Structures in High Void-Fraction Regimes
2014 International Congress on Advances in Nuclear Power Plants – ICAPP 2014. USA (2014)
•Montoya, G.; Baglietto, E.; Lucas, D.; Krepper, E.; Hoehne, T.
Comparative Analysis of High Void Fraction Regimes using an Averaging Euler-Euler Multi-Fluid Approach and a Generalized Two-Phase Flow (GENTOP) Concept
22nd International Conference on Nuclear Engineering – ICONE 22. Czech Republic (2014)
Montoya, G.; Baglietto, E.; Lucas, D.; Krepper, E.
Development and Analysis of a CMFD Generalized Multi-Field Model for Treatment of Different Interfacial Scales in Churn-Turbulent and Transitional Flows
CFD4NRS-5 – Application of CFD/CMFD Codes to Nuclear Reactor Safety Design and their Experimental Validation. Switzerland (2014)
https://www.hzdr.de/db/!Publications?pSelTitle=18077&pSelMenu=-1&pNid=3016
Shuiqing Zhan, Mao Li, Jiemin Zhou, Jianhong YangYiwen Zhou Applied Thermal Engineering 2014, 73, 803–816 [CrossRef]
T. T. DeviB. Kumar Thermophysics and Aeromechanics 2014, 21, 365–382 [CrossRef]
R.M.A. MasoodA. Delgado Chemical Engineering Science 2014, 108, 154–168 [CrossRef]
×M. Pourtousi, J.N. SahuP. Ganesan Chemical Engineering and Processing: Process Intensification 2014, 75, 38–47 [CrossRef]
Flow regimes
Turbulence models | Churn turbulent flow | [
"Chemistry"
] | 1,222 | [
"Flow regimes",
"Fluid dynamics"
] |
44,328,965 | https://en.wikipedia.org/wiki/Indulata%20Sukla | Indulata L. Sukla (7 March 1944 – 30 June 2022) was an Indian academic, who was professor of mathematics for more than three decades at Sambalpur University, Sambalpur, Odisha.
She did her schooling from Maharani Prem Kumari Girls’ School and B.Sc. with Mathematics Honours from M.P.C. College, Baripada. She completed her M.Sc. in Mathematics from Ravenshaw College, Cuttack in 1966, and had a brief stint as a lecturer in M.P.C. College, before moving to the University of Jabalpur with a CSIR Fellowship to pursue Ph.D. under the supervision of Tribikram Pati. While pursuing her researches, she joined Sambalpur University in November 1970 as a lecturer in the School of Mathematical Sciences, and continued there till her retirement in March 2004.
She is the author of the textbook Number Theory and Its Applications to Cryptography (Cuttack: Kalyani Publishers, 2000).
In her research, she worked with English mathematician Brian Kuttner on Fourier Series.
She was a Life Member of the American Mathematical Society (AMS) and the Indian Mathematical Society (IMS).
Awards and honours
The Orissa Mathematical Society (OMS) gave her the Lifetime Achievement Award for her work in Number Theory, Cryptography and Analysis. She received the award from Professor Ramachandran Balasubramanian, Director of the Institute of Mathematical Sciences, Chennai at the 42nd Annual Conference of OMS held at Vyasanagar Autonomous College, Jajpur Road, Orissa on 7 February 2015.
Selected publications
.
.
References
1944 births
2022 deaths
20th-century Indian mathematicians
Scientists from Odisha
People from Baripada
Fellows of the American Mathematical Society
Number theorists
Women scientists from Odisha
20th-century Indian women scientists
20th-century Indian women mathematicians
Sambalpur University alumni | Indulata Sukla | [
"Mathematics"
] | 385 | [
"Number theorists",
"Number theory"
] |
44,329,422 | https://en.wikipedia.org/wiki/Gallipot | A gallipot is a small jar, traditionally of glazed earthenware, used by apothecaries for holding ointment or medicine. In the 21st century, gallipots are available in plastic as well.
The term gallipot, recorded from the 15th century, may derive from the idea of pots originally imported in galleys, and has also been used for small pots used for other purposes – such as preparing an individual portion of custard or melting wax while making fishing flies.
The 16th-century Gallipot Inn in Hartfield, Sussex, England, is said to take its name "from the small glazed earthenware pots made to contain medicines and ointments that were once produced on-site".
Gallipots in a variety of shapes are held in several museums.
References
Surgical instruments
Containers | Gallipot | [
"Chemistry"
] | 169 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
44,329,487 | https://en.wikipedia.org/wiki/HYSPLIT | The Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) is a computer model that is used to compute air parcel trajectories to determine how far and in what direction a parcel of air, and subsequently air pollutants, will travel. HYSPLIT is also capable of calculating air pollutant dispersion, chemical transformation, and deposition. The HYSPLIT model was developed by the National Oceanic and Atmospheric Administration (NOAA) Air Resources Laboratory and the Australian Bureau of Meteorology Research Centere in 1998. The model derives its name from the usage of both Lagrangian and Eulerian approaches.
Model development
Early interest in computing air parcel trajectories stemmed from the nuclear arms race of the Cold War. In 1949, the United States government used wind data from radiosonde balloon measurements to determine the likely sources of air parcel trajectories to find a Soviet atomic test site. The initial version of HYSPLIT (HYSPLIT1) was developed in 1982 and obtained meteorological data solely from rawinsonde measurements, and its dispersion calculations assumed uniform daytime mixing and no mixing at night. The second version of HYSPLIT (HYSPLIT2) improved upon HYSPLIT1 by varying the mixing strength. The third version of HYSPLIT (HYSPLIT3) utilized numerical weather prediction models to compute meteorology rather than rawinsonde data alone, improving spatial and temporal resolution of the model. HYSPLIT4, created in 1998, serves as the basis for current model versions.
Applications
The HYSPLIT model is widely used for both research applications and emergency response events to forecast and establish source-receptor relationships from a variety of air pollutants and hazardous materials. Examples of use include:
Back trajectory analysis to establish source-receptor relationships
Tracking and forecasting radioactive material
Real-time wildland fire smoke predictions
Wind blown dust
Stationary sources of anthropogenic emissions
The HYSPLIT model can be run interactively on the Real-Time Environmental Applications and Display System (READY) web site or installed on PC, Mac, or Linux applications, which use a graphical user interface, or automated through scripts ('PySPLIT' package in Python, 'openair' and 'splitr' packages in R). HYSPLIT is rather unusual in that it may be run in client-server mode (HYSPLIT-WEB) from the NOAA website, allowing members of the public to select gridded historical or forecast datasets, to configure model runs, and retrieve model results with a web browser. Annual trainings on the installation, configuration, and use of the modeling system and its applications are offered by HYSPLIT developers.
Wildland fire smoke forecasting
The HYSPLIT model is extensively used by United States Land Management Agencies to forecast potential human health impacts from wildland fire smoke. Smoke from wildland fires can directly impact both the public and wildfire personnel health. The U.S. Department of Agriculture Forest Service AirFire Research Team uses HYSPLIT as a component of its BlueSky modeling framework to calculate the likely trajectories of smoke parcels given off by a fire. When combined with various other independent models of fire information, fuel loading, fire consumption, fire emissions, and meteorology within the BlueSky framework, the user can calculate the downwind concentrations of several pollutants emitted by a fire, such as Carbon Dioxide or Particulate Matter. This information is useful for land management and air regulatory agencies to understand the impacts from both planned and unplanned wildland fires and the smoke-related consequences of a spectrum of wildfire management tactics and mitigation strategies. In emergency response situations, incident management teams can deploy technical specialist Air Resource Advisors to assist with predicting and communicating smoke impacts to a wide variety of stakeholders, including incident teams, air quality regulators, and the public. Air Resource Advisors are specially trained to interpret BlueSky forecasts to provide timely smoke impact and forecast information to address public health risks and concerns.
Back trajectory analysis
One popular use of HYSPLIT is to establish whether high levels of air pollution at one location are caused by transport of air contaminants from another location. HYSPLIT's back trajectories, combined with satellite images (for example, from NASA's MODIS satellites), can provide insight into whether high air pollution levels are caused by local air pollution sources or whether an air pollution problem was blown in on the wind. Analyzing back trajectories over extended periods of time (month-year) can begin to show the geographic origin most associated with elevated concentrations. Several methods for identifying the contribution of high concentrations exist, including frequency based approaches, potential source contribution function, concentration weighted trajectory, and trajectory clustering.
For example, HYSPLIT back trajectories show that most air pollution in Door County, Wisconsin originates from outside the county. This map shows how air travels to the pollution monitor in Newport State Park. Because the monitor at Newport State park is near the shore, only the red lines (which show the lower air currents) meaningfully depict the path of ozone to the monitor. Unfortunately, as shown on the map, these lower air currents carry polluted air from major urban areas. But further inland, the air from higher up mixes more, so all color lines are significant when tracing the path of air pollution further inland. Fortunately, these higher air currents (shown in green and blue) blow in from cleaner, mostly rural areas.
Limitations
Although the HYSPLIT model has been improved since its inception in the 1980s, there are several considerations for users. Key among them are the model's inability to account for secondary chemical reactions and reliance on the input meteorological data's resolution, which can have coarse temporal and spatial resolution. Users should evaluate results carefully in areas with complex terrain. Despite its use in a wide range of emergency response events, HYSPLIT is not a U.S. Environmental Protection Agency (U.S. EPA) preferred or recommended model for regulatory purposes. AERMOD, a steady-state gaussian plume dispersion model, is the US EPA's preferred model for estimating point source impacts for primary emitted pollutants. Photochemical grid models, like the Community Multi-scale Air Quality Model (CMAQ), can simulate the complex chemical and physical processes in the atmosphere (including secondary formation of air pollutants) at a large scale.
See also
Air pollution dispersion terminology
Atmospheric dispersion modeling
List of atmospheric dispersion models
Useful conversions and formulas for air dispersion modeling
References
External links
AirFire Research Team BlueSky Modeling Framework
Air Resource Advisors
Air pollution
Atmospheric dispersion modeling
Wildfire suppression equipment
Firefighting | HYSPLIT | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 1,395 | [
"Atmospheric dispersion modeling",
"Environmental modelling",
"Environmental engineering"
] |
44,329,504 | https://en.wikipedia.org/wiki/Jos%C3%A9%20Zagal%20Moya | 'Jose H. Zagal Moya (born in Talca Chile, December 19, 1949) is a Chilean scientist educated at the University of Chile with postgraduate training in the United States of America with a Ph.D. degree from Case Western Reserve University, Cleveland Ohio and postdoctoral training at Brookhaven National Laboratory , Upton, New York. At present he is a Distinguished Professor, Department of Chemistry and Materials, Faculty of Chemistry and Biology, Universidad de Santiago de Chile (USACH) where he directs the Laboratory of Electrocatalysis since 1982. He got his Ph.D. in chemistry Case Western Reserve University, US (1978) and was postdoctoral fellow at Brookhaven National Laboratory, Upton, New York, in 1982. His main research efforts are focused on the fundamentals of electron transfer reactions that are relevant for energy conversion and sensors. He has contributed in the area of electrocatalysis, electrodes modified with metal macrocyclics, electrochemistry of biological molecules, the catalysis of the reduction of molecular oxygen and many other reactions of relevance, conductive polymers, electrochemical sensors and in pioneering work in the establishment of non-linear correlations between thermodynamic properties of molecular catalysts and their electrochemical reactivity. These contributions are essential in the development of non-precious metal catalysts for energy conversion devices and electrochemical sensors. [1][2][3]
He also has contributed in the field of corrosion, conductive polymers and his well-known volcano correlations for the electrocatalytic properties of surface-confined molecular catalysts
Prizes and distinctions
He was awarded by the President of Chile, Eduardo Frei Ruiz-Tagle the Presidential Chair in Science in 1996 by a Committee chaired by a Nobel Prize in Chemistry Rudolph Marcus and including Physics Nobel Laureate David Gross. He received the Silver Medal “University Merit” in 1998 and the Gold Medal in 2002 and the Manuel Bulnes Medal in 2013. He was distinguished by Conicyt with “Fondecyt Diploma” for being awarded more than 10 consecutive research grants without rejects in 2012. He still remains unbeaten in Fondecyt. He has been awarded two Milenium Projects as Alternative Responsible Scientist and has participated in many other associative research projects in Chile and abroad. He was appointed by the President of Chile Sebastian Piñera Echeñique and the Minister of Education, Member of the Superior Council of Research of Conicyt for the period 2010–2013. In 2014 he received the Dr. Alberto Zanlungo Prize. He has received several distinctions from international scientific societies. He was appointed Fellow by the Royal Society of Chemistry (RSC) of the UK in 2018. He became a Member of the RSC in 2017. He received the Fellow Medal from the International Society of Electrochemistry based in Europe and the Fellow Medal from the US-based Electrochemical Society (ECS) both in 2014. This year he was incorporated as an Active Member to the Academy of Sciences of Latin America (ACAL) and became an Emeritus Member of The Electrochemical Society of the United States of America. He created the Chilean Secretary of ISE in 2003 and was his first chilean representative. He also created the Chile Section of ECS in 2011 and is presently its Chairman. He was a co-founder of the Chilean Society of Carbonaceous Materials and is presently its President. He is also the President of the Iberoamerican Chemical Society.
In 2024 he was awarded Chile's highest honor for scientific merit, the "Premio Nacional de Ciencias Naturales" or "National Prize in the Natural Sciences" .
Publications
He has published over 222 papers (200 indexed publications) coedited four books, 9 book chapters and 3 patents. H impact factor= 41 (Web of Science), H= 42 Scopus and H= 48 (Google Scholar) with more 7460 citations in Google. He has created three patents with the Chilean Navy on electrode materials for energy conversion. He has presented more than 300 papers in national and international meetings, including some plenary and invited lectures and keynotes worldwide. He has been a guest editor for the Journal of Applied Electrochemistry, The International Journal of Electrochemistry and recently in Current Opinion in Electrochemistry
Training of professionals and scientists
He was involved in the creation of the Masters and Ph.D. Programs in Chemistry from his university and it was the very first doctoral program in Usach. He has supervised more 60 thesis: 36 undergraduate and professional students: 20 doctorates, 5 masters and 9 postdocs, some coming from Europe (Russian Federation, France, Germany, Spain and Italy).
Books
1) N4 Macrocyclic Metal Complexes. J.H. ZAGAL, F. Bedioui, J.P. Dodelet (Eds), Springer New York ( 2006).
Electroquímica: voltametrías sobre electrodo sólido. Fethi Bedioui, Silvia Gutiérrez Granados, Alejandro Alatorre Ordaz y 2) J.H. ZAGAL, Sello Editorial Usach, (2009).
3https://www.springer.com/la/book/9783319311708) “Electrochemistry of MN4 macrocyclic metal complexes” Volume 1 Energy: “Electrochemistry of MN4 Macrocyclic complexes” J.H. Zagal, F. Bedioui (Eds) Springer Switzerland (2016) (segunda edición) 316 páginas.
4) https://www.springer.com/gb/book/9783319313306 “Electrochemistry of MN4 macrocyclic metal complexes” Volume 2 Biomimesis, Electroanalysis, and Electrosynthesis of MN4 complexes” J.H. Zagal, F. Bedioui, (Eds) Springer Switzerland (2016) (segunda edición) 436 páginas
Editorial boards
He has been involved in many editorial boards of scientific journals. He was member of the editorial board of the Journal of Applied Electrochemistry (1988-2010), Journal of the Chilean Chemical Society (1984-2007) and Electrocatalysis (2010-2015) and is presently member of the Editorial Board of several international publications: Journal of Solid State Electrochemistry (Springer), International Journal of Electrochemistry (Hindawi), Electrochemistry Communications (Elsevier), Journal of the Serbian Chemical Society, Electrochemical Energy Technology (De Goutyer) and Chimica Nova and Frontiers in Chemistry. He has been a Guest Editor for the Journal of Applied Electrochemistry, Current Opinion in Electrochemistry and for the International Journal of Electrochemistry.
Hobbies
Professor Zagal is also a man of many talents: he sings and plays several instruments, including the guitar and the scottish bagpipes. He also writes poetry, paints and draws cartoons. He played Caiphas in the Opera Rock Jesus Christ Superstar in the early 70's. He has been a volunteer firemen with the 14th British and Commonwealth Fire & Rescue Company in Santiago since 1972 and is also the official piper of his company. Some of his caricatures have been published in the magazine “Interface” of the Electrochemical Society and in the Journal of the Serbian Chemical Society. He is a devoted train enthusiast. He has built large replicas or working steam locomotive and full size freight wagons. He also collects full size railway items including 12 wagons and 2 locomotives, one steam and an electric locomotive. With other enthusiasts he started in the 80's the "Chilean Association for the Preservation of the Railways". With two other enthusiasts he owns the "Puangue Station" which is one of the few preserved railway stations in rural areas.
References
1949 births
Living people
Chilean chemists
Electrochemistry
Academic staff of the University of Santiago, Chile | José Zagal Moya | [
"Chemistry"
] | 1,605 | [
"Electrochemistry"
] |
44,330,423 | https://en.wikipedia.org/wiki/Richard%20Zach | Richard Zach is a Canadian logician, philosopher of mathematics, and historian of logic and analytic philosophy. He is currently Professor of Philosophy at the University of Calgary.
Research
Zach's research interests include the development of formal logic and historical figures (Hilbert, Gödel, and Carnap) associated with this development. In the philosophy of mathematics Zach has worked on Hilbert's program and the philosophical relevance of proof theory. In mathematical logic, he has made contributions to proof theory (epsilon calculus, proof complexity) and to modal and many-valued logic, especially Gödel logic.
Career
Zach received his undergraduate education at the Vienna University of Technology and his Ph.D. at the Group in Logic and the Methodology of Science at the University of California, Berkeley. His dissertation, Hilbert's Program: Historical, Philosophical, and Metamathematical Perspectives, was jointly supervised by Paolo Mancosu and Jack Silver.
He has taught at the University of Calgary since 2001, and holds the rank of Professor. He has held visiting appointments at the University of California, Irvine and McGill University. Zach is a founding editor of the Review of Symbolic Logic and the Journal for the Study of the History of Analytic Philosophy, and is also associate editor of Studia Logica, and a subject editor for the Stanford Encyclopedia of Philosophy (History of Modern Logic). He serves on the editorial boards of the Bernays edition and the Carnap edition. He was elected to the Council of the Association for Symbolic Logic in 2008 (ASL) and he has served on the ASL Committee on Logic Education and the executive committee of the Kurt Gödel Society.
References
External links
Official Website
LogBlog: A Logic Blog
Departmental information page
Society for the Study of the History of Analytical Philosophy
Open Logic Project
Year of birth missing (living people)
Living people
20th-century Canadian philosophers
21st-century Canadian philosophers
Academic staff of the University of Calgary
Mathematical logicians
Philosophers of mathematics
Austrian logicians | Richard Zach | [
"Mathematics"
] | 395 | [
"Philosophers of mathematics",
"Mathematical logic",
"Mathematical logicians"
] |
44,331,153 | https://en.wikipedia.org/wiki/Amazon%20Echo | Amazon Echo, often shortened to Echo, is a brand of smart speakers developed by Amazon. Echo devices connect to the voice-controlled intelligent personal assistant service Alexa, which will respond when a user says "Alexa". Users may change this wake word to "Amazon", "Echo", "Computer", and other options. The features of the device include voice interaction, music playback, making to-do lists, setting alarms, streaming podcasts, and playing audiobooks, in addition to providing weather, traffic and other real-time information. It can also control several smart devices, acting as a home automation hub.
Amazon started developing Echo devices inside its Lab126 offices in Silicon Valley and in Cambridge, Massachusetts as early as 2010. The device represented one of its first attempts to expand its device portfolio beyond the Kindle e-reader.
Amazon initially limited the first-generation Echo to Amazon Prime members or just by invitation, but it became widely available in the United States in mid 2015, and subsequently in other countries. Additionally, the Alexa voice service is available to be added to other devices, and Amazon encourages other companies' devices and services to connect to it.
History
Work on the Amazon Echo began in 2011, known as "Project D". It was named this because the Kindle was Project A and the Fire Phone was Project B. The Amazon Echo was an offshoot of Project C. Project C is unknown, even though the work on it has stopped. The Amazon Echo was originally supposed to be called the Amazon Flash. The wake word, the word that makes the device responsive, for the Echo used to be "Amazon". Both of these attributes were disliked by Lab126, the division of Amazon that conducts research and development and creates computer hardware. Lab126 believed that "Amazon" is too much of a commonly used word, and the device would react when it was not intended to. Jeff Bezos, the CEO of Amazon, ended up being influenced by Lab126 to change the name of the device to the Amazon Echo and the wake word to "Alexa". The Amazon Echo was originally pitched as only a smart speaker, it was not originally intended to be a smart home hub, as it is now, until after it was launched. As Alexa, the artificial intelligence (A.I.) that powers the Amazon Echo, improved, the device became more of a controlling center for smart home appliances. Dave Isbitski, the chief developer evangelist for the Echo and Alexa, received calls from smart home manufacturers to discuss connecting their devices, after the release of the Amazon Echo. But smart home devices had a problem: people were not buying smart home devices because they often required an extra app in order to be used, which was not much better than just using the device manually.
The Amazon Echo (1st Generation) was initially released in 2014 alongside the voice of the product, Alexa. Alexa is a voice associated with the Amazon Echo that will respond to questions and requests through artificial intelligence. Amazon has claimed that the voice of Alexa was inspired by electronic communications systems featured in the television series Star Trek: The Original Series and Star Trek: The Next Generation. The Echo was announced on Nov 6, 2014 and was initially available by invitation only. It became available to all customers on July 14, 2015.
The Echo featured prominently in Amazon's first Super Bowl broadcast television advertisement in 2016.
In March 2016 Amazon released a less expensive version of the Amazon Echo, called the Amazon Echo Dot. This device is an ice hockey puck sized version of the original Amazon Echo released in 2014, and it has the same capabilities. This product was designed to be used in smaller rooms such as bedrooms due to its limited speaker capabilities (size) or to be paired with an external speaker. In November 2016 the second generation of the Echo Dot was released for a lower price with improved voice recognition and new colors.
The second generation of the Amazon Echo was released in October 2017. This update offered better voice recognition and a fabric covering exterior. Subsequently, other variants of the Amazon Echo have been released.
In May 2017 Amazon released the now-discontinued Amazon Tap, a portable, slightly smaller version of the Amazon Echo. Although the two products are similar the Tap is battery powered, portable, and requires the touch of a button in order to enable voice commands.
In April 2017 the Amazon Echo Look was released to invitees only, as an Amazon Echo with a built in camera. It was designed as a speaker, that is also handy with artificial intelligence that has smart algorithms to help users pick out outfits. It was released to the general public in August 2018. The Look was phased out in 2020.
In June 2018 the Amazon Echo Show was released to the public as a device with a 7-inch screen used for streaming media, making video calls and the use of Alexa. The second generation of the device was made available in November 2018 and features a 10-inch screen with improved speakers.
Features
Overview of operation
In the default mode, the device continuously listens to all speech, monitoring for the wake word to be spoken, which is primarily set up as "Alexa" (derived from Alexa Internet, the Amazon-owned Internet indexing company). Echo's microphones can be manually disabled by pressing a mute button to turn off the audio processing circuit.
Echo devices require a wireless Internet connection in order to work. Echo's voice recognition capability is based on Amazon Web Services and the voice platform Amazon acquired from Yap, Evi, and IVONA (a Polish-based specialist in voice technologies used in the Kindle Fire). The device requires one time setup by pairing it with Amazon's Alexa app, which gives the user more control over features.
The smart speakers perform well with a "good" (low-latency) Internet connection, which minimizes processing time due to minimal communication round trips, streaming responses and geo-distributed service endpoints. While the application is free, an Amazon account is required, and setup is not possible without one.
Available services
Echo devices offer weather from AccuWeather and news from a variety of sources, including local radio stations, BBC, NPR, and ESPN from TuneIn and iHeartRadio. Echo can play music from the owner's Amazon Music accounts and has built-in support for other streaming music services like Apple Music, Spotify, Deezer, Pandora and Sirius XM among others, and has support for IFTTT and Nest thermostats. Echo can also play music from non-compatible music streaming services such as Google Play Music from a phone or tablet via Bluetooth. Echo maintains voice-controlled alarms, timers, shopping and to-do lists and can access Wikipedia articles. Echo will respond to questions about items in one's Google Calendar. It also integrates with Yonomi, Philips Hue, Belkin Wemo, SmartThings, Insteon, and Wink. Additionally, integration with the Echo is in the works for Countertop by Orange Chef, Sonos, Scout Alarm, Garageio, Toymail, MARA, and Mojio. Questions like "Who is Barack Obama?" are answered by reading the first few lines of the corresponding Wikipedia article.
Echo devices also have access to "skills" built with the Alexa Skills Kit. These are third-party-developed voice applications which add functionality to any Alexa-enabled device. Examples of skills include the ability to play music, answer general questions, set an alarm, order a pizza or a ridesharing car (e.g., Uber, Lyft), and so on. The Alexa Skills Kit is a collection of self-service application programming interfaces (API), tools, documentation and code samples. Developers can also use the "Smart Home Skill API", a new addition to the Alexa Skills Kit, to extend Alexa's compatibility with cloud-controlled lighting and thermostat devices. All of the code runs in the cloud and nothing is on any user device. A developer can follow tutorials to learn how to build voice-response capability for their new and existing applications.
In November 2018, Amazon added Skype calling ability to all of their Echo products. Echo devices that have a display have access to video calling.
In May 2019, Amazon released Alexa Guard. If "Away mode" is enabled and an Echo device detects the sound of smoke alarms, carbon monoxide alarms, or glass breaking, it will send alerts to the Alexa app on smartphones. If the user has professional monitoring, it can send alerts directly to the security provider. It can also switch smart lights on and off to make it look like someone is home. A paid feature called Guard Plus enables other features such as playing the sound of a dog barking when an intruder is detected.
Voice Services
The Alexa Voice Service (AVS) allows developers to voice-enable connected products with a microphone and speaker. The AVS enables volume control, audio playback, and speech recognition. The devices have natural lifelike voices resulting from speech-unit technology. High speech accuracy is achieved through sophisticated natural language processing algorithms built into the Echo's text-to-speech engine.
Software updates
As with all Alexa devices, the functionality of Echo smart speakers periodically evolves as Amazon releases new software for it. Most new releases fix bugs in addition to including enhanced functionality. New releases are pushed to the devices on a gradual basis so it may take several days to a week or more for a particular device to be updated. Because much of Echo's intelligence lies in the cloud, significant functional enhancements can be made to Echo without updating the software version it is running. For example, in April 2015, the Echo added the ability to give live sports scores without updating the software version running on the device.
Smart Home
The Amazon Echo is able to connect to many different smart home devices. Thermostats, humidifiers, lightbulbs, plugs, dog and cat feeder, door locks, cameras, thermostats, security systems, speakers, WiFi, televisions, vacuums, microwaves, printers, and other smart home devices can now all be controlled through Alexa. Alexa can be used to activate and deactivate all of these smart home appliances, as well as change their settings depending on the device. For example, Alexa can be used to change the temperature in a house through a thermostat, turn off the lights with smart lights, put out dog or cat food via a smart pet feeder, and activate the security systems via a smart security system. The user is able to organize these smart home devices by putting them into groups. For example, a user can make a "Music Group" on the Amazon Echo. The Amazon Echo will be able to play music and other media in multiple rooms in a house through other Echos and speakers that are in the "Music Group". Along with multiple groups, an Amazon Echo can hold multiple profiles. Switching between the profiles can allow users to play their music, access their calendars, and use their accounts for shopping, instead of just using one person's.
In December 2021, an outage of Amazon's cloud service caused smart home devices to stop working.
Hands-free
Amazon Echos are able to make calls and send messages. Users can make calls to another Amazon Echo or speaker that is in the house by calling the device name. Users can also make calls and send messages to other people that have an Amazon Echo. This is done by connecting the user's contacts to the Amazon Echo. The user's Amazon Echo will call their contact's Amazon Echo. They will be able to have a conversation using the Amazon Echos. Messages will go to the contact's phone, in the Alexa App. The message can also be played on the Echo.
Variants
Echo
The first-generation Amazon Echo consists of a 9.25 inch (23.5 cm) tall cylinder speaker with a seven-piece microphone array.
The Echo hardware complement includes a Texas Instruments DM3725 ARM Cortex-A8 processor, 256MB of LPDDR1 RAM and 4GB of storage space. , the first-generation Echo maintained an 83% score on GearCaliber, a review aggregator.
Although the Echo is intended to be voice-controlled at the unit, a microphone-enabled remote control similar to the one bundled with the Amazon Fire TV is available for purchase. The remote was also bundled with early units. An action button on top of the unit is provided for user setup in a new location, and the mute button allows the microphones to be turned off. The top half-inch of the unit rotates to increase or decrease the speaker volume. The Echo must be plugged in to operate since it has no internal battery.
Echo provides dual-band Wi-Fi 802.11a/b/g/n and Bluetooth Advanced Audio Distribution Profile (A2DP) support for audio streaming and Audio/Video Remote Control Profile (AVRCP) for voice control of connected mobile devices.
The mainline Linux kernel is able to boot the Amazon Echo since version 5.6.
In September 2020, the 4th gen Echo was announced replacing the Echo and Echo Plus devices in a new spherical form-factor. The Echo brings the Echo Plus' Zigbee smart home hub with support for Amazon Sidewalk.
Limited editions
As part of a holiday promotion, Seattle Seahawks player Marshawn Lynch drove the Treasure Truck around Seattle in December 2016 selling a limited-edition beast-mode Echo with a custom skin. The beast-mode version was a first-generation Echo that responded to a user's commands with Marshawn Lynch's voice, instead of the Alexa voice.
In November 2017, a Product Red version of the second-generation Echo was announced as a limited edition item.
Another special version of Echo is the Alexa Super Skills Collectible edition, which was given to select Amazon Alexa developers who published five skills between July 22 and October 30, 2017. This special variant comes with a white mask, a blue cape, and a blue belt.
Availability
Amazon initially limited the first-generation Echo to Amazon Prime members or just by invitation, but it became widely available in the United States in mid 2015. In 2016, the Echo became available in the United Kingdom and Germany.
, the Echo was available in more than 80 countries: Albania, Austria, Anguilla, Argentina, Australia, Austria, Barbados, Belarus, Belgium, Bermuda Bolivia, Bosnia and Herzegovina, Bulgaria, Cambodia, Canada, Chile, Colombia, Costa Rica, Croatia, Cyprus, the Czech Republic, Denmark Ecuador, El Salvador, Estonia, Finland, Ghana, Gibraltar Germany, Greece, Grenada, Hong Kong, Indonesia, Jamaica, Kenya, Hungary, Iceland, India, Ireland, Italy, Japan, Latvia, Liechtenstein, Lithuania, Luxembourg, Macao, Malaysia, Malta, Mexico, Namibia, the Netherlands, New Zealand, North Macedonia, Norway, Panama, Peru, Philippines, Panama, Peru, Poland, Portugal, Puerto Rico, Romania, Saint Kitts and Nevis, Serbia, Singapore, Slovakia, Slovenia, South Korea, Sri Lanka, Suriname, Sweden, Switzerland, Taiwan, Tanzania, Thailand, Trinidad and Tobago, Turkey, the United Kingdom, the United States, Uruguay, Vanuatu, Venezuela and Zambia.
In 2018, Amazon and Microsoft jointly announced a solution to integrate their digital assistants so that Cortana, Microsoft's voice assistant, could be called from an Amazon Echo device and Alexa could be called from Windows devices, including PCs. In January 2019, Microsoft CEO Satya Nadella announced that Cortana would no longer be a platform competitor to Alexa or Google Assistant, but rather a voice skill to access Microsoft 365 via other voice assistants. As of April 2019, Alexa was the only Cortana-integrated voice assistant, which gave it exclusive access to Microsoft's suite of business applications.
Echo Dot
1st Gen
In March 2016, Amazon unveiled the original Amazon Echo Dot, which is a hockey puck-sized version of the Echo designed to be connected to external speakers due to the smaller size of the onboard speakers, or to be used in rooms such as the bedroom as an alternative to the full-sized Echo. Despite its smaller form factor, the Amazon Echo Dot retains all the core functionalities of the original Amazon Echo, ensuring a seamless voice-controlled experience for users.
Additionally, users have the option to enhance the portability of the Echo Dot with third-party external batteries, providing extended usage on the go.
2nd Gen
The second generation of the Amazon Echo Dot became available on October 20, 2016. It is priced lower, has improved voice recognition, and is available in black, grey and white. The Echo Spatial Perception (ESP) technology allows several Echo and Dot units to work together so that only one device answers the request. , the Echo Dot maintained a 78% score on GearCaliber, based on 23 reviews.
On August 18, 2017, an Amazon promotion allowed Amazon Prime customers to receive a 100% price reduction on the Echo Dot (from $49.99 to $0.00). Amazon never commented on the promotion or gave any indication of how many Dots were given away.
3rd Gen
The third generation Echo Dot, introduced in September 2018, featured a new design with fabric covers, departing from the previous plastic or metal cylinder design. These fabric-covered Echo Dots also incorporated upgraded speaker drivers while retaining their core functionalities, including 3.5mm audio output.
In January 2019, Amazon's SVP of devices and services, Dave Limp, revealed that over 100 million Alexa-enabled devices had been sold. The company's earnings reports and press releases also reveal that the Echo Dot has been among the top-selling products on Amazon.com for 2017 and 2018.
4th Gen
In September 2020, the fourth generation Echo Dot was revealed with a new spherical design and 30% smaller compared to the 3rd gen Echo.
5th Gen
In September 2022, the fifth generation Echo Dot introduced several enhancements, including a new temperature sensor, an improved audio experience with clearer vocals and deeper bass, and cutting-edge ultrasonic motion detection technology. Notably, it also features eero Built-in as a Wi-Fi extender, expanding its capabilities for smart homes and offering users a broader range of options.
Amazon Tap
The Amazon Tap is a smaller portable version of the Echo. The Tap can do the many things the Echo can do; however, as it is battery-powered, it is also portable. Initially, the user had to press an activation button on the front of the Tap to speak commands. However, a February 2017 software update allows the option of activating the Tap with an activation word, just like the Echo and the Dot. Some of the limitations of the Tap include not being able to stream music as part of a group and not being able to send announcements to the device. Additionally the Tap does not support "Drop In" feature and as a result cannot be used for two-way voice communication. Amazon has discontinued the Tap. This has encouraged 3rd party accessory manufacturers to make available battery add-on units for other Echo products.
Echo Look
In April 2017, the Amazon Echo Look was introduced as a camera with Alexa built-in, for US$20 more than the first-generation Echo. The device can provide artificial intelligence outfit recommendations, take photos, and record videos; in addition to the features available on the Echo. It offers Amazon Alexa's key feature plus a camera to take full-length photos and 360-degree videos with built-in AI for fashion advice. As a consumer product, it helps catalog users' outfits and rates their looks based on "machine learning algorithms with advice from fashion specialists.
The device was initially only available for purchase by invitation-only in the U.S. However, it became generally available on June 6, 2018. Three years later, Echo Look owners received an email from Amazon stating that the device would soon stop working, because Amazon was discontinuing production and sales of the device. Echo Look owners had a device that they could not use.
Echo Show
In May 2017, Amazon introduced the Echo Show, which features a tactile 7-inch liquid-crystal display screen that can be used for playing media, making video calls (5 MP front camera), and other features. The Echo Show was offered for purchase at a price of $229.99 on June 28, 2017, and was initially only available in the U.S.
A second generation of the Echo Show was unveiled at an Alexa-themed product event by Amazon on September 20, 2018, for release the following month. The new device has a 10-inch touchscreen, improved speakers, and mesh casing. Amazon has released three additional sizes of the Echo Show making them available in 5-, 8-, and 15-inch displays. These devices broke the traditional naming mechanism of naming strictly on generation. They are known as the Echo show 5, Echo Show 8, and Echo Show 15.
Echo Spot
On September 27, 2017, Amazon launched the Echo Spot, a hemispherical device that has the same functions as an Echo Show. The device has a 2.5-inch circular screen, and looks like an alarm clock. The device sold for $129.99. In 2019, the Echo Spot has been discontinued in all regions. On July 9, 2024, Amazon brought back the Echo Spot, but with a different design. The device now resembles the look of the Echo Pop, with a 2.83" inch touch screen with a half-circle tinted cover glass and a speaker. Unlike the 2017 version, videocalling and smart home cameras are not available on the device. The device sold for $79.99.
Echo Plus
On September 27, 2017, Amazon announced the Echo Plus, which released on October 31, 2017. It shares design similarities with the first-generation Echo, but also doubles as a smart home hub, connecting to most common wireless protocols to control connected smart devices within a home. It incorporates seven second-generation far field microphones and noise cancellation, while also supporting Dolby Sound.
In September 2018, a second-generation Echo Plus was released. The new version has a fabric covering and includes an embedded temperature sensor. The Echo Plus has since been discontinued in 2020.
Echo Flex
On November 14, 2019, Amazon released the Echo Flex for $24.99. It is a small device with a speaker that can be plugged directly into a wall outlet. It has a full-sized USB Type-A port into the bottom to charge other devices or into which additional accessories, such as a motion sensor, can be plugged.
Echo Studio
In November 2019, Amazon introduced Echo Studio, a Dolby Atmos-compatible surround sound Alexa speaker. Compared to other Alexa speakers, it was the biggest and the loudest.
Speakerless devices
At an Alexa-themed product launch event in September 2018, Amazon announced an Echo device designed for cars. The device connects with the user's smartphone over Bluetooth and offers driving direction, in addition to other Alexa functionality. Echo Auto became available as an invite-only product to US customers near the end of 2018.
The Echo Input is an Alexa input device with no on-board speakers. It must be connected to external speakers for audio output. The Echo Link is a higher-end version of the Echo Input, with additional output ports and a volume knob. The Echo Link Amp has the same controls of the Link, but with an amplifier.
Accessories
Along with the second-generation Echo, Amazon announced two new accessories. The Echo Buttons can be used while playing games on Echo devices, such as Jeopardy!. The Echo Connect is a small adapter that plugs into any Echo and a home phone line, allowing the Echo to make voice calls through a home phone number.
In September 2018, Amazon announced the Echo Sub, a subwoofer that connects to other Echo speakers, and the Echo Wall Clock, which can display how much time is remaining on timers set with an Echo device.
Wearable
Amazon announced the Echo Loop in September 2019, a smart ring with a button that activates Alexa. The Echo Loop uses Bluetooth to connect to a smartphone for Internet access. The Echo Frames smartglasses, which support prescription lenses, were also announced on the same day. In 2020, it was announced that Echo Loop would be discontinued. On September 20, 2023, Amazon unveiled the third generation of Echo Frames and a collaboration with Carrera Eyewear on two frame designs.
Privacy concerns
There are concerns about the access Echo has to private conversations in the home, or other non-verbal indications that can identify who is present in the home and who is not—based on audible cues such as footstep cadence or radio and television programming. Amazon responds to these concerns by stating that Echo only streams recordings from the user's home when the "wake word" activates the device, though the device is technically capable of streaming voice recordings at all times, and in fact will always be listening to detect if a user has uttered the word.
Echo uses past voice recordings the user has sent to the cloud service to improve response to future questions the user may pose. To address privacy concerns, the user can delete voice recordings that are currently associated with the user's account, but doing so may degrade the user's experience using voice search. To delete these recordings, the user can visit the "Manage My Device" page on Amazon.com or contact Amazon customer service. In May 2018, it was reported that an Echo device had sent a recorded conversation to an acquaintance of a user who did not intend for this to happen. Amazon apologized and conjectured that one part of the conversation had been misinterpreted as a command to distribute it.
Echo uses an address set in the Alexa companion app when it needs a location. Amazon and third-party apps and websites use location information to provide location-based services and store this information to provide voice services, the Maps app, Find Your Device, and to monitor the performance and accuracy of location services. For example, Echo voice services use the user's location to respond to the user's requests for nearby restaurants or stores. Similarly, Echo uses the user's location to process the user's mapping-related requests and improve the Maps experience. All information collected is subject to the Amazon.com Privacy Notice.
Amazon retains digital recordings of users' audio spoken after the "wake up word", and while the audio recordings are subject to demands by law enforcement, government agents, and other entities via subpoena, Amazon publishes some information about the warrants it receives, the subpoenas it receives, and some of the warrant-less demands it receives, allowing customers some indication as to the percentage of illegal demands for customer information it receives.
As Amazon employed ex-US-security-chief Gen Keith B. Alexander in autumn 2020, Edward Snowden commented laconically: "It turns out 'Hey Alexa' is short for 'Hey Keith Alexander."
Echo as criminal evidence
During the course of the investigation into the November 22, 2015, death of Victor Collins in the home of James Andrew Bates in Bentonville, Arkansas, police sought the data stored on the Amazon Echo on the premises as evidence, but were refused by Amazon. The conflict was resolved when Bates consented to the release of his personal information that was held by the company.
Concerns relating to in-car smart systems
In February 2017, Luke Millanta successfully demonstrated how an Echo could be connected to, and used to control, a Tesla Model S. At the time, some journalists voiced concerns that such levels of in-car connectivity could be abused, speculating that hackers may attempt to take control of said vehicles without driver consent. Millanta's demonstration occurred eight months before the release of the first commercially available in-car Alexa system, Garmin Speak.
Limitations
Purchasing merchandise in the categories of apparel, shoes, jewelry, and watches is not available. In addition, Amazon Prime Pantry, Prime Now, or Add-On items are not supported by Alexa's ordering function, while the shopping list function allows no more than one item to be added at a time.
Echo has provided inconsistent responses when asked common questions to which users would expect better answers. Echo sometimes confuses certain homophones.
See also
Google Nest
HomePod
INVOKE
References
External links
Unacceptable, where is my privacy? Exploring Accidental Triggers of Smart Speakers
Amazon (company) hardware
Products introduced in 2014
Smart speakers
Smart home hubs | Amazon Echo | [
"Technology"
] | 5,798 | [
"Home automation",
"Smart home hubs"
] |
44,331,238 | https://en.wikipedia.org/wiki/Overwatch%20%28video%20game%29 | Overwatch (retroactively referred to as Overwatch 1) was a 2016 multiplayer first-person shooter video game by Blizzard Entertainment. The game was first released for PlayStation 4, Windows, and Xbox One in May 2016 and Nintendo Switch in October 2019, with cross-platform play supported across all platforms. Described as a "hero shooter", Overwatch assigned players into two teams of six, with each player selecting from a large roster of characters, known as "heroes", with unique abilities. Teams worked to complete map-specific objectives within a limited period of time. Blizzard added new characters, maps, and game modes post-release, all free of charge, with the only additional cost to players being optional loot boxes to purchase cosmetic items.
Overwatch is Blizzard's fourth major franchise and came about following the 2014 cancellation of a massively multiplayer online role-playing game, Titan. A portion of the Titan team were inspired by the success of team-based first-person shooters like Team Fortress 2 and the popularity of multiplayer online battle arena games, creating a hero-based shooter which emphasized teamwork. Some elements of Overwatch borrow concepts from the canceled Titan project. Overwatch was unveiled at the 2014 BlizzCon event and was in a closed beta from late 2015 through early 2016. An open beta before release drew in nearly 10 million players.
Overwatch received universal acclaim from critics, who praised the game for its accessibility, the diverse appeal of its hero characters, its cartoonish art style, and enjoyable gameplay. Blizzard reported over in revenue during the first year of its release and had more than 50 million players after three years. During its lifetime, Overwatch was considered to be among the greatest video games of all time, receiving numerous game of the year awards and other accolades. The game was a popular esport, with Blizzard funding and producing the global Overwatch League. On October 3, 2022, the Overwatch servers were shut down in preparation for the beta release of its sequel, Overwatch 2, the next day.
Gameplay
Overwatch was an online team-based game generally played as a first-person shooter. The game featured several different game modes, principally designed around squad-based combat with two opposing teams of six players each. Players selected one of over two dozen pre-made hero characters from one of three class types: Damage heroes that deal most of the damage to attack or defend control points, Tank heroes that can absorb a large amount of damage, and Support heroes that provide healing or other buffs for their teammates. Each hero had a unique skill kit, defining their intrinsic attributes like health points and running speed, their primary attacks, several active and passive skills, and an ultimate ability that can only be used after it has been charged through dealing damage to enemies and healing allies. Players could change their hero during the course of a match, as a goal of Overwatch design was to encourage dynamic team compositions that adapt to the situation. The game's genre has been described by some journalists as a "hero shooter", due to its design around specific heroes and classes.
The game featured game modes for casual play, competitive ranked play, and for supporting esports competitions including Blizzard's Overwatch League. These modes were generally centered around sequentially securing control of points on the map, or escorting a payload between points on the map, with one team attacking while the other defends. Other modes set aside for casual matches include solo and team deathmatch, capture-the-flag, and unique modes run during various seasonal events. More recent updates had enabled users to craft their own game modes with a limited set of scripting tools. Regardless of winning or losing a match, players gained experience towards a player level, and on gaining a new level, received loot boxes that contain cosmetic items that they can use to customize the appearance of the hero characters but otherwise does not affect gameplay. Loot boxes could also be purchased through microtransactions.
Plot
The backstory to Overwatch is described through animated shorts and other information distributed by Blizzard in promoting the game.
Overwatch is set sixty years into the future of a fictionalized Earth, thirty years after the resolution of what is known as the "Omnic Crisis." Before the Omnic Crisis, humanity had been in a golden age of prosperity and technology development. Humans developed robots with artificial intelligence called "Omnics", which were put to use to achieve economic equality, and began to be treated as people in their own right. The Omnic Crisis began when the worldwide automated "omnium" facilities that produced them started producing a series of lethal, hostile robots that attacked humankind. After individual nations' efforts failed to ward off the Omnics, the United Nations quickly formed Overwatch, an international task force designed to combat this threat and restore order.
Two veteran soldiers from the Soldier Enhancement Program were put in charge of Overwatch: Gabriel Reyes and Jack Morrison. Though Overwatch successfully quelled the robotic uprising and brought many talented individuals to the forefront, a rift developed between Reyes and Morrison due to Reyes being the official leader of the group despite everyone viewing the more popular Morrison as their true leader. Eventually, Morrison was made the leader of Overwatch while Reyes was given charge of Blackwatch, Overwatch's covert operations division, fighting terrorist organizations like Talon, a group that appears to be trying to start a second Omnic Crisis, and Null Sector, a group of Omnics that revolted against the society that persecuted Omnics following the first Crisis. Overwatch continued to maintain peace across the world for several decades in what came to be called the "Overwatch Generation" as the team gained more members, but the rift between Morrison and Reyes intensified. One night, Blackwatch was dispatched to arrest a notorious mobster with ties to Talon. After infiltrating the compound, Reyes chose to execute the mobster rather than let him buy his way out of prison. This action caused Blackwatch and their less heroic actions to be exposed to the public. Several allegations of wrongdoing and failures were leveled at Overwatch, leading to a public outcry against the organization and in-fighting between its members, prompting the UN to investigate the situation. During this, an explosion destroyed Overwatch's headquarters in Switzerland, purportedly killing Morrison and Reyes among others. The UN passed the Petras Act, which dismantled Overwatch and forbade any Overwatch-type activity.
Overwatch is set six years after the Petras Act; without Overwatch, corporations have started to take over, fighting and terrorism have broken out in parts of the globe, and there are signs of a second Omnic Crisis occurring in Russia. The intelligent gorilla Winston, a former member of Overwatch, decides to begin reforming Overwatch to protect the peace once again despite the Petras Act, with the team members recruiting old friends and gaining new allies in their fight. It is revealed that Reyes and Morrison were not killed in the explosion resulting from their battle: Morrison became a masked vigilante known as "Soldier: 76", who is trying to uncover the reasons why Overwatch was shut down. Reyes joined Talon, leading to him being experimented on by Moira who then became "Reaper", a terrorist with a Death-like appearance.
Development
Overwatch was developed by Blizzard Team 4 and published by Blizzard Entertainment. The game came about in the aftermath of Blizzard's decision to cancel the massively multiplayer online role-playing game Titan in 2013, a project that had been in development for about seven years. While most others assigned to the project were transferred to other departments within Blizzard, a small team of about 40 people, led by director Jeff Kaplan, were tasked to come up with a new concept for a game in a few months. After some brainstorming, they came onto the idea of a hero team-based shooter, building upon the success of games like Team Fortress 2 and multiplayer online battle arenas. They started with assets developed for Titan to demonstrate the proof-of-concept and were greenlit to build out the full game, the first new intellectual property that Blizzard had developed since StarCraft.
The intra-company experience of Titan cancellation served to help drive the narrative and setting. They created an optimistic vision of the near-future, some decades following the Omnic Crisis and the formation and collapse of the peacekeeping Overwatch group. This allowed them to create a diverse cast of characters, including non-human ones, and colorful settings from around the globe. The Overwatch team continues to support the game through free updates, the introduction of new characters, maps, game modes, cosmetic items, seasonal events, and external media to support the game's narrative, as well as continuously tuning how the individual heroes play by monitoring meta-game statistics and user feedback. New characters and maps were added regularly to the game since launch, expanding the original hero roster from 21 in May 2016 to 32 by April 2020. Since April 2020 however, no heroes have been released, as the development team is focused on creating Overwatch 2.
Overwatch development had been led by Kaplan through April 2021, after which he departed Blizzard. Kaplan's duties were taken over by Aaron Keller following his departure.
Release and marketing
Announcement and beta
Overwatch was formally announced at the BlizzCon event on November 7, 2014; the game was playable during the event to all attendees, with fourteen characters available to select from. During this event, Blizzard released a cinematic trailer and an extended gameplay video for the game. A month after the BlizzCon event, in December 2014, Blizzard published character introduction videos to its YouTube channel and followed up on this May 2015 by posting weekly videos of game footage and character highlights.
A closed beta period for Overwatch across all three platforms began on October 27, 2015. The closed beta was put on "extended break" in December and brought back in February 2016. Following the March 2016 release announcement, Blizzard announced an open beta period from May 5 to 9 for any registered user of the Battle.net client. The open beta proved popular with Blizzard reporting over 9.7 million players participating, and as a way of showing thanks, extended the open beta period by one extra day.
Release
In the week before release, Blizzard arranged to have three giant-sized boxes (approximately tall) of various Overwatch heroes, as if being sold as packaged action figures, put on display across the globe at Hollywood, Paris, and Busan, South Korea. The displays were created by Alliance Studios, led by Steve Wang, who has collaborated with Blizzard before on past projects, and Eddie Yang. After planning the design of the sculptures in January 2016, teams across the world, including Droga5, Scicon, Stratasys and Egads, raced to print, finish and assemble the works in time for the game's release. Propelled by Overwatch, Blizzard had over 50% of the American advertisement share among gaming industry brands from May 16 to June 15, 2016.
Overwatch was released for PlayStation 4, Windows, and Xbox One on May 24, 2016. Blizzard allowed retailers to sell physical copies of the game a day before to help players prepare for the servers' launch.
Two special editions of Overwatch were released alongside the base game. The Origins Edition, available both as a downloadable and retail product, includes the base game and five additional character skins, as well as other bonus items for other Blizzard games via Battle.net. The Collectors Edition, only available as retail, includes the Origins Edition content as well as a statue of Soldier: 76, one of the playable characters, along with the game's soundtrack on CD and a source book.
Post-release
In honor of its first anniversary in 2017, Blizzard released a digital Game of the Year edition of Overwatch. It includes all content from the Origins Edition, in addition to ten free loot boxes. Blizzard had expressed interest in supporting cross-platform play between console systems in the future, though initially had no plans for Windows-supported cross-play due to the precision advantage of keyboard-mouse controls over controller-based ones. However, in June 2021, Blizzard brought cross-platform play to Overwatch across all supported platforms, with a beta test launched at the start of the month before full release by the end of June. To deal with the control differences, the game's competitive mode would still remain segregated between console players and computer players, but all other game modes would allow for cross-play on any combination of platforms, after users register their account via Battle.net.
The game was announced for Nintendo Switch during the September 2019 Nintendo Direct, the Switch had the Overwatch: Legendary Edition and was released in North America and Europe on October 15, 2019, and in Japan on November 29, 2019. The Switch version, developed by Iron Galaxy, includes support for the console's gyroscopic controls for some actions, such as controlling Junkrat's Rip-tire, and maneuvering Wrecking Ball in his spherical form. The version is equivalent to the existing version of the game on other platforms, including all heroes, maps, and game modes, although Switch players will not be able to participate in the game's current Competition season as to give players a chance to adjust to the console's controls before introducing ranked play. The version has a game case for retailers in North America and Europe but does not include a physical Game Card, featuring a download code instead.
The Xbox One version of the game received an optimization patch in March 2021, adding new performance settings when played using backwards compatibility on Xbox Series X/S, allowing the game to run at up to 120 frames per second on supported monitors.
Reception
Before its release, Overwatch experienced a period of pre-launch attention not typically expected; Game Revolution noted that reputation has quickly permeated through cyberspace, attracting attention from people who may not traditionally put down $40 to $60 each time a new first-person shooter releases." The game's open beta, which attracted 9.7 million players, was very heavily covered by the media.
Overwatch received "universal acclaim" upon release, according to review aggregator Metacritic. IGN's Vince Ingenito praised the game's characters and maps, writing "Overwatch takes just about every possible opportunity to make its cast and locales seem like people and places rather than puppets and scenery." Ingenito added that the game has a "strong online experience that gets you into games quickly and reliably." The Verge Andrew Webster praised Overwatch and previous titles Titanfall and Splatoon as "friendly online shooters" that have room for both new and casual players who may not desire to master the game but can still compete fairly with others, and for expert players that can utilize the various heroes to adapt to the dynamic tactics of the game. Webster went on to cite the atmosphere of Overwatch as a reason for the game's approachability, writing, "The first thing that makes Overwatch world appealing and approachable is, well, its world. This isn't the dour brown-and-grey shooter you might be used to. Instead, it's bright and colorful, with a cast of characters that's eclectic and diverse." Caty McCarthy of Kill Screen echoed similar thoughts, writing "When playing Overwatch, the player is absorbed by its radiating positivity. It's a world filled with lively color and energetic, playful competition, much like Nintendo's creative kid-friendly ink-shooter Splatoon." Mike Minotti of VentureBeat commending the team-based gameplay, the game's diverse character roster, and colorful settings, as well as the unlockable cosmetics earned through level progression and the smooth server connection. Referencing its similarities to Team Fortress 2, Minotti confirmed that "[Overwatch has] distinct classes, the team- and objective-based combat, and a bright, cartoon-like art style," and that "Overwatch certainly takes plenty of inspiration from Valve online shooter series," but opines that "[Overwatch is] just better." Daniel Tack of The News & Observer positively received the game, expressing that "no matter what happens – win or lose – you're going to have fun," adding that "the game's strength lies in its simplicity and polish." Tack went on to praise the game's characters, writing "Unforgettable characters are the lifeblood and driving force of Overwatch." The Denver Post Hugh Johnson lauded the game for its emphasis on characters, rather than focusing on traditional first-person shooter tropes, such as weapon load-outs and incremental level upgrades. Johnson went on to insist that the characters are balanced writing, "The big question with class-based shooters like these is whether or not the characters are balanced," expressing that "some characters are naturally better, but no character is so overpowered that their mere presence spells doom for their opponents." In June 2016, Vulture Joshua Rivera listed Overwatch as one of the "best video games of 2016 (so far)," writing, "It's hard to separate Overwatch the game from Overwatch the phenomenon—and why bother, both are fascinating."
The online magazine Inverse, while expressing an overall positive reception for the game, pointed out the balance of McCree (know known as Cassidy), teams composed of only one character, issues with matchmaking, and the Play of the Game as problems that should be fixed by the game's development team. Gabe Gurwin of Digital Trends, directed criticism at Blizzard, for their decision to exclude the story from the game, which left players "with a great game, a great story, and no way to reconcile the two."
Shortly after the game's competitive play mode was released, Kotaku Nathan Grayson stated that "Overwatch competitive mode [is not] all that bad, for how new and unpolished it is," but opined that "high-stakes competition and toxicity tend to go hand-in-hand, and Overwatch competitive mode already has an ugly toxic stain." Grayson concluded his piece with "Overwatch is, most of the time, a feel-good team game. Introducing high-stakes competition with a muddled message about the importance of individual skill drags the game into confused, oftentimes negative territory. If Blizzard wants this thing to work, they're gonna have to figure out a competitive framework that's true to Overwatch spirit, rather than just the spirit of competition." Kaplan acknowledged that with the introduction of competitive mode that the whole of the Overwatch community has become more toxic, and they are continually adapting elements behind the scenes to help deal with aggressive players more responsibly, while trying to promote more enjoyable matches.
Sales
A week from its launch, Blizzard reported over seven million Overwatch players with a total accumulated playtime of 119 million hours; Blizzard reported more than 10 million players by mid-June and has reported continued increases in the player base, with 60 million players as of April 2021 whilst possibly counting temporary free accounts. The NPD Group, a video game industry tracking firm, reported that Overwatch was the third best-selling retail video game (nb. discounting digital sales through Battle.net) in the US in May 2016 on the month of its release, and was the top-selling game in June 2016; the NPD Group later reported it was the 7th highest selling game by revenue (excluding Battle.net sales) in the United States for all of 2016. With digital sales, Overwatch was the fastest-selling game during its release month. SuperData Research estimated that Overwatch brought in more than $269 million in revenues from digital sales worldwide in May, and over $565 million in sales on personal computers along by the end of 2016, making it the highest-grossing paid game for personal computers that year.
In Activision-Blizzard's quarterly earnings report for Q1 2017, the company reported that Overwatch revenues had exceeded one billion dollars, the eighth such property owned by the company to do so. In June 2016, Gametrics, a South Korean internet cafe survey website, reported that Overwatch overtook League of Legends as the most popular game played across 4,000 of South Korea's PC bangs at the time. In 2018, Overwatch raised over $12.7 million for the Breast Cancer Research Foundation, which they generated from selling a special pink-colored Mercy skin where all proceeds went towards it. By July 2019, total in-game spending in Overwatch exceeded one billion dollars as estimated by SuperData, the sixth Activision-Blizzard product line to reach this metric.
Controversies
While the developers were aiming to avoid sexualization of the characters, there was some criticism of the female characters of the game during its development. In February 2015, Anita Sarkeesian commented on the lack of diversity in the female heroes' body types from the game's first twelve revealed characters, while Nathan Grayson of Kotaku remarked that "Overwatch women are mostly super slim and clad in cat suits." In March 2015, the development team revealed a new character, Zarya, who is a female Russian bodybuilder with a muscular body, and pledged commitment to diversity.
Following promotional images featuring the female character Tracer in March 2016, a thread on Blizzard's official forums drew attention to one of Tracer's victory poses, which was criticized by a user as out of character and oversexualized. Kaplan apologized for the pose, stating "The last thing we want to do is make someone feel uncomfortable, under-appreciated or misrepresented," and confirmed that Blizzard planned to replace the pose. Kaplan's response drew mixed reactions from the gaming community, with many claiming Blizzard had forgone its creative control over the game and censored its content to placate one offended user, while others praised Blizzard's willingness to listen to the community and adhere to standards for portraying a character according to their personality. Kaplan later stated that the team was already unsure of the pose and was thinking of changing it. The following week, a replacement pose was released, although it was noted to be similar to the original pose. The replacement pose was alleged to be influenced by Billy DeVorss cheesecake pin-up art. The pose was replaced during the game's beta period.
Following the game's release, some of the alternative outfits for characters had come under criticism for using cultural stereotypes, such as a Native American headdress option for the character of Pharah, who seemed to be primarily of Egyptian origin. Kaplan noted that they had considered if these outfits were appropriate, and believed they were respecting the cultures of the characters they had created and would make necessary changes if they felt there were valid concerns. Kaplan commented that many players have responded positively to these outfits and feel they fit in appropriately with the idealized version of Earth. Later game developments showed that Pharah was set out as a half-Egyptian/half-Native American character, making such outfits appropriate in hindsight.
In July 2016, the President of the Universal Society of Hinduism (Rajan Zed) urged Blizzard to remove two of Symmetra's hero cosmetic items from the game since they could be seen as inappropriate and not accurate towards the beliefs and practices of Hinduism. In Hinduism, devotees put their destinies in the hands of their gods and goddesses; this is a stark contrast to how he believes they are portrayed within the game. Zed has in the past commented on other video game depictions of Hindu-inspired gods, such as in the multiplayer online battle arena (MOBA) game Smite.
In Overwatch Asia servers, there were problems with numerous players using cheats tied to the growing number of younger players using PC bangs in South Korea that allowed them to play Overwatch on an inexpensive hourly rate rather than purchasing the game. As these players do not need permanent accounts, they can use disposable Battle.net accounts and employ game hacks without repercussions, and if that account is banned, they can quickly make another and continue playing. Blizzard continues to block these accounts at a rate of thousands per day, but have not been able to find a more permanent solution. Subsequently, Blizzard announced that players from South Korea would be required to log into a Battle.net account to play the game from February 2017 onward, which requires a difficult-to-spoof resident registration number among other unique information, which Blizzard believes would help to alleviate the problem.
As to maintain a fair competitive field on consoles, Blizzard has spoken out against the use of input converters that would allow console players to use keyboard/mouse controllers, believing this gives an advantage to players that can afford the converter. Some players have criticized the ability to use these converters, as players with them often populate the top of the competitive ranking ladders. Though Blizzard has appealed to Sony and Microsoft to either prevent such converters, or to detect when such converters are used as to be able to segregate players into servers based on this, disabled players have spoken out against such action, as many need to use such converters to play the game on consoles lacking the ability to use a normal controller.
After a year from its release, journalists observed that the player community was becoming more toxic, disrupting the enjoyment of playing the game. It was believed this came from the nature of the game that requires teamwork, and when teammates see players unwilling to switch to different heroes to balance the team or otherwise play for individual gains, this would cause the teammates to become angry and lash out at the player, become griefers and throw the match, or other harmful behavior that would spread over time, particularly in the game's competitive mode. Players are able to report malicious users with in-game tools, and Blizzard can ban players for egregious actions, but they do not attempt to segregate out bad actors from the larger pool (a method used by other developers in multiplayer games), instead keeping an inclusive community for all non-banned players, which is believed to contribute to the growing toxicity. Kaplan said in a September 2017 update that Blizzard was very well aware of the problem, and have worked to improve their in-game player behavior reporting tools to help combat the toxicity, but because they have had to put greater effort into this, they are distracted from developing new features and content for the game. Kaplan urged the community to consider how they can improve individually and as a whole to help combat the situations.
In November 2017, the Belgian Gaming Commission announced that it was investigating Overwatch alongside Star Wars Battlefront II to determine whether loot boxes constituted unlicensed gambling. Many Asian and European countries view loot boxes as a form of gambling and have since decided to make them illegal for companies to sell directly to their consumers in their games. Blizzard has chosen to work with these regions to follow their gambling laws while staying true to their microtransaction focused business model. Within China, Blizzard has allowed their players to purchase in-game currency and receive loot boxes as a "gift." In addition to this loot box change, China has required Blizzard to publicly disclose the exact odds of winning each tier of item within said loot box. While initially loot boxes were not seen as gambling within the United States; the US Federal Trade Commission decided in 2018 to investigate the legality of the projected soon to be 50 billion dollar industry of microtransactions.
Awards
Overwatch won numerous awards in 2016, including being named Game of the Year at The Game Awards, D.I.C.E. Awards, and Game Developers Choice Awards, as well as several awards and nominations highlighting its game direction and as a leading multiplayer game. Several publications, including IGN, GameSpot, Game Revolution, EGMNow, GamesTM, The Escapist, Game Informer and Eurogamer, named Overwatch the best game of 2016, receiving 102 "game of the year" awards across critics and reader polls.
Giant Bomb gave it the awards for "Best Debut" and "Best Multiplayer", and put it in third place for "Game of the Year". Polygon and Slant Magazine also put the game in third place for "Game of the Year", while PC Gamer gave it the award for "Best Multiplayer". Besides "Game of the Year", The Escapist gave it the awards for "Best Shooter and Multiplayer". Game Informer gave it the awards for "Best Competitive Multiplayer" and "Best Shooter". At IGN's Best of 2016 Awards, the game won the awards for "Best Shooter", "Best eSports Game", "Best Multiplayer", and "PC Game of the Year". In IGN's Best of 2017 Awards, the game won the People's Choice Award for "Best Spectator Game", while Game Informer gave it the award for "Best Shooter as Service" in their 2017 Shooter of the Year Awards.
In the years since its release, Overwatch has continued to be nominated and awarded for its strength as an esports game, as well as the ongoing content added to the title.
Legacy
Overwatch fan base has been noted to be generally kind and supportive; Daniel Starkey of Wired wrote, "where many fresh games struggle with an endless stream of player complaints and developer-prodding, Overwatch community is vivacious and jubilant." A gamer with cerebral palsy publicly praised the game's customizable controls, which let him make his first snipe in a video game. One of Blizzard's artists, Roman Kenney, drew concept art based on one player's daughter's original Overwatch character design. Blizzard altered one of the game's maps to include a tribute to an avid Chinese fan of the game who died from injuries while trying to stop a motorcycle theft on the day before the game's public release.
Blizzard has encouraged fans of Overwatch to make artistic content based on the game. To support this, Blizzard released the hero reference kit before release, providing official colors and costume and weapon designs for all 21 heroes present at the game's launch. Fans have used these, the game's animated media, and other assets to create a large amount of content, including art, cosplay, and anime opening-style music videos. Some Overwatch concepts have created internet memes such as "Gremlin D.Va", which focuses on the character D.Va, portrayed through Western gamer stereotypes. In some cases, Blizzard has reciprocated these fan creations back into the game, such as an emote for D.Va, based on the Gremlin meme. At the 2017 D.I.C.E. Summit in February 2017, Kaplan said that much of Overwatch narrative is now being borne out of the game's fans, adding "We love it, that it belongs to them...We're just the custodians of the universe." Kaplan recognizes that he himself is seen as an Overwatch character within the fan community, and following similar steps that Hearthstone lead designer Ben Brode has done, has continued to engage with the fan community.
Pornographic fan art of the game is popular, with Pornhub searches of Overwatch characters partaking in sexual activities spiking by 817% shortly after the release of the open beta. A large amount of such pornographic fan works are created with Valve's Source Filmmaker tool and make use of the game's assets, which were ripped from the game during its closed beta and consequently spread over the internet. Blizzard made efforts to remove the works. Kaplan stated that while the studio does not want to infringe on anyone's freedom of expression, Blizzard is mindful that many players are not adults and would hope the community would try to keep such imagery away from them.
Franchise
Related media and merchandise
Blizzard opted to tell the story of Overwatch across various mediums, rather than include a story mode; Chu stated, "One of the things that's really great is we're able to leverage the strengths of these different mediums to tell different parts of the story," citing Soldier: 76's appearances in fake news reports, an animated video narrated from his perspective, as well as the Hero short.
In March 2016, Blizzard announced that they would be releasing comics and animated shorts based on Overwatch in 2016. The related media included plans for a since-cancelled graphic novel called Overwatch: First Strike, which would have focused on the story of several in-game characters, including Soldier: 76, Torbjörn, Reaper, and Reinhardt.
Blizzard began releasing the series of animated shorts in March 2016; the shorts maintained the style of the game's cinematic trailer, which centered on a battle in which Tracer and Winston fought Reaper and Widowmaker in the Overwatch Museum. A collection of these cinematic sequences played in movie theaters across the United States as part of the game's launch event. The first episode of the animated short series, Recall, was released on March 23. It centers on Winston and Reaper, and features flashbacks to Winston's childhood.
Blizzard published three digital comic series during Overwatch 2016–2022 run: Overwatch, Tracer - London Calling, and New Blood. These comics were also printed on hard cover through Dark Horse Comics. Further Overwatch literature including an art book, cook book, short stories, and novelizations were also published.
Overwatch characters and elements have been brought over to the crossover MOBA game Heroes of the Storm.
Various toy and figurine manufacturers produced merchandise lines featuring Overwatch characters. These manufacturers included Funko, Good Smile Company, Nerf and its parent company Hasbro, as well as The Lego Group.
Esports
Overwatch was not developed with any dedication towards esports, focusing on "building a great competitive game" first and foremost, according to Morhaime, though they recognized that the game had potential as an esports game through internal testing. Kaplan stated that while esports was not a design goal, they included and planned for features for the game to support the competitive community. This included the introduction of the game's competitive mode some months after the game's launch after seeing how players took towards Overwatch; Blizzard saw the ladder-approach they used as a means for skilled players to reach high ranks as to be noticed by esport team organizers. Dan Szymborski writing for ESPN stated that Overwatch was poised as the next big esport for having a sufficiently different look and playstyle from established esports games like Counter-Strike: Global Offensive and Call of Duty, enough variety in maps and characters, and strong support from Blizzard to maintain the game for a long time. Bryant Francis writing for Gamasutra noted the speed and short match times of Overwatch make the game highly favorable for viewership, further supporting the game as an esports title.
Just before the game's release, PC Gamer writer Stefan Dorresteijn contacted professional esports players and hosts for their opinions. Longtime esports host Paul Chaloner stated that "[Overwatch] needs a much better spectator system," going on to elaborate, "Right now, it's incredibly difficult for commentators and viewers to see the skills of the players: who used their ultimates and how did they interact? Who is on cooldown and who has changed hero?" Fellow esports player Seb Barton and Michael Rosen criticized the game's map designs and game modes; Barton remarked that "the game modes are a little hit and miss," adding that "King of the hill [Control] is super exciting and fast-paced but then you have the payload [Escort] maps, which are just a snoozefest for everyone involved." Rosen expressed a need for tweaking to the maps used for the control game mode, as they are "just too prone to the snowball effect. The moment the attacking team captures the first control point they don't just have the momentum but also the last advantage for the second and final capture point."
The first organized, prize-winning competitions for Overwatch started in mid-2016, a few months after launch. In November 2016, Blizzard hosted their own Overwatch World Cup, allowing users to vote for teams to represent their nation or region, with finals taking place during their BlizzCon event. Overwatch grew increasingly in South Korea since it was released. It topped gaming cafes in Korea in terms of player count, surpassing that of League of Legends.
At the 2016 BlizzCon, Blizzard announced their plans for their Overwatch League, using an organization of permanent teams in league placements similar to more traditional North American professional sports leagues, rather than the use of promotion and relegation used in a series like League of Legends Championship Series. The OWL would being preseason play in December 2017, with its first season taking place in 2018.
Sequel
Overwatch 2, a standalone sequel, was announced at BlizzCon on November 1, 2019, and was released on October 4, 2022, as a free-to-play game for Nintendo Switch, PlayStation 4, PlayStation 5, Windows, Xbox One, and Xbox Series X and S.
Originally, it was planned for Overwatch and Overwatch 2 to have a "shared multiplayer environment" between it and the original Overwatch, so that the players in either game could compete together in the existing player versus player (PvP) modes, retaining all unlocked cosmetics and other features, but with the transition to free-to-play, Overwatchs servers were shut down on October 3, 2022, in favor of the sequel, and all players were transitioned to Overwatch 2.
A significant departure was moving to a five-versus-five PvP mode, with a restriction of only allowing one tank in play on a team as to help improve the perceived speed of gameplay. To this end, many heroes had their skill kit reworked, or in some cases, were reclassified into a new hero class.
Another change in the transition to free to play was the elimination of loot boxes in favor of a season pass. As part of the transition, Blizzard ended purchases of loot boxes on August 30, 2022 (though players were still able to earn these as drops in-game), and any unopened loot boxes in a player's inventory on Overwatch 2 release were automatically opened and contents credited to the player.
Notes
References
External links
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Xbox One X enhanced games | Overwatch (video game) | [
"Physics"
] | 8,143 | [
"Asymmetrical multiplayer video games",
"Symmetry",
"Asymmetry"
] |
44,331,442 | https://en.wikipedia.org/wiki/Architectural%20style | An architectural style is a classification of buildings (and nonbuilding structures) based on a set of characteristics and features, including overall appearance, arrangement of the components, method of construction, building materials used, form, size, structural design, and regional character.
Architectural styles are frequently associated with a historical epoch (Renaissance style), geographical location (Italian Villa style), or an earlier architectural style (Neo-Gothic style), and are influenced by the corresponding broader artistic style and the "general human condition". Heinrich Wölfflin even declared an analogy between a building and a costume: an "architectural style reflects the attitude and the movement of people in the period concerned.
The 21st century construction uses a multitude of styles that are sometimes lumped together as a "contemporary architecture" based on the common trait of extreme reliance on computer-aided architectural design (cf. Parametricism).
Folk architecture (also "vernacular architecture") is not a style, but an application of local customs to small-scale construction without clear identity of the builder.
Styles in the history of architecture
The concept of architectural style is studied in the architectural history as one of the approaches ("style and period") that are used to organize the history of architecture (Leach lists five other approaches as "biography, geography and culture, type, technique, theme and analogy"). Style provides an additional relationship between otherwise disparate buildings, thus serving as a "protection against chaos".
The concept of style was foreign to architects until the 18th century. Prior to the era of Enlightenment, the architectural form was mostly considered timeless, either as a divine revelation or an absolute truth derived from the laws of nature, and a great architect was the one who understood this "language". The new interpretation of history declared each historical period to be a stage of growth for the humanity (cf. Johann Gottfried Herder's Volksgeist that much later developed into Zeitgeist). This approach allowed to classify architecture of each age as an equally valid approach, "style" (the use of the word in this sense became established by the mid-18th century).
Style has been subject of an extensive debate since at least the 19th century. Many architects argue that the notion of "style" cannot adequately describe the contemporary architecture, is obsolete and ridden with historicism. In their opinion, by concentrating on the appearance of the building, style classification misses the hidden from view ideas that architects had put into the form. Studying history of architecture without reliance on styles usually relies on a "canon" of important architects and buildings. The lesser objects in this approach do not deserve attention: "A bicycle shed is a building; Lincoln Cathedral is a piece of architecture" (Nikolaus Pevsner, 1943). Nonetheless, the traditional and popular approach to the architectural history is through chronology of styles, with changes reflecting the evolution of materials, economics, fashions, and beliefs.
Works of architecture are unlikely to be preserved for their aesthetic value alone; with practical re-purposing, the original intent of the original architect, sometimes his very identity, can be forgotten, and the building style becomes "an indispensable historical tool".
Evolution of style
Styles emerge from the history of a society. At any time several styles may be fashionable, and when a style changes it usually does so gradually, as architects learn and adapt to new ideas. The new style is sometimes only a rebellion against an existing style, such as postmodern architecture (meaning "after modernism"), which in 21st century has found its own language and split into a number of styles which have acquired other names.
Architectural styles often spread to other places, so that the style at its source continues to develop in new ways while other countries follow with their own twist. For instance, Renaissance ideas emerged in Italy around 1425 and spread to all of Europe over the next 200 years, with the French, German, English, and Spanish Renaissances showing recognisably the same style, but with unique characteristics. An architectural style may also spread through colonialism, either by foreign colonies learning from their home country, or by settlers moving to a new land. One example is the Spanish missions in California, brought by Spanish priests in the late 18th century and built in a unique style.
After an architectural style has gone out of fashion, revivals and re-interpretations may occur. For instance, classicism has been revived many times and found new life as neoclassicism. Each time it is revived, it is different. The Spanish mission style was revived 100 years later as the Mission Revival, and that soon evolved into the Spanish Colonial Revival.
History of the concept of architectural style
Early writing on the subjects of architectural history, since the works of Vitruvius in the 1st century B.C., treated architecture as a patrimony that was passed on to the next generation of architects by their forefathers. Giorgio Vasari in the 16th century shifted the narrative to biographies of the great artists in his "Lives of the Most Excellent Painters, Sculptors, and Architects".
Constructing schemes of the period styles of historic art and architecture was a major concern of 19th century scholars in the new and initially mostly German-speaking field of art history. Important writers on the broad theory of style including Carl Friedrich von Rumohr, Gottfried Semper, and Alois Riegl in his Stilfragen of 1893, with Heinrich Wölfflin and Paul Frankl continued the debate into the 20th century. Paul Jacobsthal and Josef Strzygowski are among the art historians who followed Riegl in proposing grand schemes tracing the transmission of elements of styles across great ranges in time and space. This type of art history is also known as formalism, or the study of forms or shapes in art. Wölfflin declared the goal of formalism as , "art history without names", where an architect's work has a place in history that is independent of its author. The subject of study no longer was the ideas that Borromini borrowed from Maderno who in turn learned from Michelangelo, instead the questions now were about the continuity and changes observed when the architecture transitioned from Renaissance to Baroque.
Semper, Wölfflin, and Frankl, and later Ackerman, had backgrounds in the history of architecture, and like many other terms for period styles, "Romanesque" and "Gothic" were initially coined to describe architectural styles, where major changes between styles can be clearer and more easy to define, not least because style in architecture is easier to replicate by following a set of rules than style in figurative art such as painting. Terms originated to describe architectural periods were often subsequently applied to other areas of the visual arts, and then more widely still to music, literature and the general culture. In architecture stylistic change often follows, and is made possible by, the discovery of new techniques or materials, from the Gothic rib vault to modern metal and reinforced concrete construction. A major area of debate in both art history and archaeology has been the extent to which stylistic change in other fields like painting or pottery is also a response to new technical possibilities, or has its own impetus to develop (the kunstwollen of Riegl), or changes in response to social and economic factors affecting patronage and the conditions of the artist, as current thinking tends to emphasize, using less rigid versions of Marxist art history.
Although style was well-established as a central component of art historical analysis, seeing it as the over-riding factor in art history had fallen out of fashion by World War II, as other ways of looking at art were developing, and a reaction against the emphasis on style developing; for Svetlana Alpers, "the normal invocation of style in art history is a depressing affair indeed". According to James Elkins "In the later 20th century criticisms of style were aimed at further reducing the Hegelian elements of the concept while retaining it in a form that could be more easily controlled".
Practical issues
In the middle of the 19th century, multiple aesthetic and social factors forced architects to design the new buildings using a selection of styles patterned after the historical ones (working "in every style or none"), and style definition became a practical matter. The choice of an appropriate style was subject of elaborate discussions; for example, the Cambridge Camden Society had argued that the churches in the new British colonies should be built in the Norman style, so that the local architects and builders can go through the paces repeating the architectural history of England.
See also
Historicism (architecture)
History of architecture
List of architectural styles
Revivalism (architecture)
Notes
References
"Alpers in Lang": Alpers, Svetlana, "Style is What You Make It", in The Concept of Style, ed. Berel Lang, (Ithaca: Cornell University Press, 1987), 137–162, google books.
Elkins, James, "Style" in Grove Art Online, Oxford Art Online, Oxford University Press, accessed March 6, 2013, subscriber link
Elsner, Jas, "Style" in Critical Terms for Art History, Nelson, Robert S. and Shiff, Richard, 2nd Edn. 2010, University of Chicago Press, , 9780226571690, google books
Gombrich, E. "Style" (1968), orig. International Encyclopedia of the Social Sciences, ed. D. L. Sills, xv (New York, 1968), reprinted in Preziosi, D. (ed.) The Art of Art History: A Critical Anthology (see below), whose page numbers are used.
"Kubler in Lang": Kubler, George, Towards a Reductive Theory of Style, in Lang
Lang, Berel (ed.), The Concept of Style, 1987, Ithaca: Cornell University Press, , 9780801494390, google books; includes essays by Alpers and Kubler
Preziosi, D. (ed.) The Art of Art History: A Critical Anthology, Oxford: Oxford University Press, 1998,
Architectural design
Architectural history | Architectural style | [
"Engineering"
] | 2,044 | [
"Design",
"Architectural history",
"Architectural design",
"Architecture"
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44,331,535 | https://en.wikipedia.org/wiki/Fluidized%20bed%20concentrator | A fluidized bed concentrator (FBC) is an industrial process for the treatment of exhaust air. The system uses a bed of activated carbon beads to adsorb volatile organic compounds (VOCs) from the exhaust gas. Differently from the fixed-bed or carbon rotor concentrators, the FBC system forces the VOC-laden air through several perforated steel trays, increasing the velocity of the air and allowing the sub-millimeter carbon beads to fluidize, or behave as if suspended in a liquid. This increases the surface area of the carbon-gas interaction, making it more effective at capturing VOCs.
Components
The fluidized bed concentrator consists of five primary components:
Adsorption tower
Desorption tower
Thermal oxidizer
Carbon transport system
Process fans: inlet adsorber, inlet desorber, outlet oxidizer to stack
How it works
Industrial processes requiring ventilation, including paint booths, printing, and chemical production, exhaust the ventilated air to the fluidized bed concentrator at room temperature. The air first passes into the adsorption tower, where it moves through six perforated trays of clean carbon beads. The 0.7 mm bead activated carbon (BAC) fluidizes in the trays and captures the VOCs as they intermix.
The saturated carbon beads are passed from the adsorber tower to the desorber tower, where the beads are heated to 350 °F and the VOCs are released. Typically the adsorber tower is many times larger than the desorber tower, leading to an air volume reduction and an increase in VOC concentration. The ratio of adsorber size to desorber size is called the concentration ratio, and ranges from 10:1 to 100:1.
The concentrated VOC gas stream is sent from the desorb tower to a thermal oxidizer, where the organic compounds are heated to 1400 °F and oxidized, or broken down into carbon dioxide (CO2), water (H2O), and by-products. In some cases, small amounts of carbon monoxide (CO), nitrogen oxide (NOX), and other gases are produced.
Emissions and energy usage
The primary advantage of the FBC over traditional rotor concentrators lies in its ability to achieve any concentration ratio up to the lower explosive limit (LEL). This allows Honda Alabama's paint shop to switch from oxidizing 100,000 CFM of VOCs in a regenerative thermal oxidizer (RTO), to oxidizing only 1,500 CFM of VOCs in a small thermal oxidizer, at a much higher concentration. Reducing the volume of air to be oxidized from 100,000 CFM to 1,500 CFM (66:1 concentration ratio), allows for a much lower energy usage and consequently, fewer CO2 and NOX emissions.
Industries served
Paint finishing
Automotive
Aerospace
Heavy machinery
Transportation
Printing
Chemical production
Semiconductor
Food processing
See also
Volatile organic compound
National Emissions Standards for Hazardous Air Pollutants
Air pollution in the United States
Activated carbon
Air pollution
References
External links
Clean Air Act plus further links to relevant rules, reports, and programs.
Organic NESHAP
Air pollution control systems
Pollution control technologies
Air pollution in the United States
Hazardous air pollutants
United States Environmental Protection Agency
Chemical safety
Volatile organic compound abatement
Industrial processes
Fluidization | Fluidized bed concentrator | [
"Chemistry",
"Engineering"
] | 696 | [
"Fluidization",
"Chemical accident",
"Pollution control technologies",
"nan",
"Environmental engineering",
"Chemical safety"
] |
70,114,313 | https://en.wikipedia.org/wiki/Xiaomi%20Mi%2011%20Ultra | Xiaomi Mi 11 Ultra is an Android high-end smartphone developed by Xiaomi, released in April 2021. It serves as the successor to the Xiaomi Mi 10 Ultra. Unlike its China-only predecessor, the Mi 11 Ultra is available for retail in the global market.
The Mi 11 Ultra is heavily marketed around its camera capabilities. At the time of release, the Mi 11 Ultra featured the largest main camera sensor of any conventional smartphone, at 1/1.12 inch. Paired with the main camera are two auxiliary cameras, a 13mm equivalent ultra-wide angle camera and a 120mm equivalent periscope telephoto camera capable of 5x optical zoom. The Mi 11 Ultra features a 1.1-inch secondary display at the back of the phone, next to its camera module.
The Mi 11 Ultra employs a 6.81-inch WQHD+ curved OLED display with a 120 Hz refresh rate, capable of a touch sampling rate of 480 Hz and a peak brightness of 1700 nits. The Mi 11 Ultra is powered by a Snapdragon 888 chipset, the flagship Android processor at the time of release. The Mi 11 Ultra utilises a 5000 mAh battery, capable of 67W wired, 67W wireless, and 10W reverse charging. Upon release, the Mi 11 Ultra had a starting price of £1,199 in the UK, on par with the competition.
See also
List of longest smartphone telephoto lenses
References
External links
Android (operating system) devices
Phablets
Mobile phones with multiple rear cameras
Mobile phones with 8K video recording
Xiaomi smartphones
Mobile phones with infrared transmitter
Mobile phones introduced in 2021 | Xiaomi Mi 11 Ultra | [
"Technology"
] | 338 | [
"Crossover devices",
"Mobile technology stubs",
"Phablets",
"Mobile phone stubs"
] |
70,114,339 | https://en.wikipedia.org/wiki/HD%20158259 | HD 158259 is a main sequence star located away in the constellation Draco. It hosts a system of at least five planets, discovered by the SOPHIE échelle spectrograph using the radial velocity method.
Characteristics
HD 158259 is a G0 star with a rotation period of days. More detailed analysis of the spectral assigns a class of G5V, but with the metal lines of an F9 star.
Planets
Five planets have been confirmed orbiting HD 158259, along with one unconfirmed planet. These planets were discovered by N.C. Hara et.al. by the radial velocity method, published in Astronomy & Astrophysics in April 2020. The innermost planet, HD 158259 b, was also observed to transit the star by TESS. The planets orbit in a nearly 3:2 orbital resonance, with the period ratios 1.5758, 1.5146, 1.5296, 1.5130, and 1.4480, respectively, starting from the innermost pairing. A dynamical analysis has shown that the system is stable. One of the planets, HD 158259 b, is a super-Earth; the rest, including the unconfirmed HD 158259 g, are mini-Neptunes.
See also
List of exoplanets discovered in 2020 - HD 158259 b, c, d, e, and f
References
Draco (constellation)
G-type main-sequence stars
158259
085268
Planetary systems with five confirmed planets | HD 158259 | [
"Astronomy"
] | 311 | [
"Constellations",
"Draco (constellation)"
] |
70,116,823 | https://en.wikipedia.org/wiki/Mordovka | Mordovka (, , mordovki) were minted or cast silver and copper plates made in the Middle and Lower Volga region during the 16th to 18th centuries. The obverse side usually featured coarse, stylized images of a horseman, horse, bird, and other figures. The reverse side had inscriptions made from sets of letters, often imitating Russian kopecks. According to the Kazan Chronicle, mordovki, referred to as pieces of silver (серебреники) in chronicle, were used as both adornment sewn on clothes and as coins.
A distinctive version of the mordovki had a triangular design. They sometimes depict a woman in a tall headdress. Numerous hoards containing large numbers of mordovki have been discovered in the Volga Region and Central Asia.
Etymology
The term mordovka ( lit.'Mordvin woman') is in use since 19th century among Russian numismatists for all similar coins or tokens found in Volga region.
History
Russian ethnographer had been collecting this kind coins for more than 30 years and divided his corpus in two classes he called Type A and type B. Type B coins or tokens were made of different alloys and used mostly in Moksha women traditional costumes as decoration. Zaikovsky notes that even he himself knows one of the places where this kind of craft was produced (Traka village). He points at the fact that Tatar, Kyrgyz or Russian women never use them as decoration. Moreover, a legend exists they were money in old times. Interesting that he notes the coins are called mordvki or mortki when mordka was a term for Old Russian coin equal to of a ruble which as he comments "never existed". He never received a positive reaction from Russian numismatists as they all believed these coins are just decoration tokens or "Post-Peter kopecks imitations". They hadn't share Zaikovsky's enthusiasm regarding his findings since they just did not believe the mere idea that Mordvins considered illiterate village folk could ever have their own money. He lists hidden treasure cites with buckets of mordovkas found and attract numismatists community's attention to the problem of the existing early monetary systems in Volga region and coins authenticity.
Type A coins
Type A are minted of silver and look like authentic coins. They have readable inscriptions. Saratov State University scholar Iosif Cherapkin, expert in Moksha language, had examined type A coins and confirmed their authenticity. Inscription resembled Cyrillic without soft signs and was readable in Old (Middle) Moksha and says 'It circulates as 1/2 of gold'.
Cherapkin's Inscription
Cherapkin's inscription on the coins as had been attested is written in Old or precisely Middle Moksha in Greek uncial script with digamma 'ͷ' or an unknown variant of Cyrillic without soft signs. Three of the four word forms are older that those attested in Nicolaes Witsen's Dutch-Moksha dictionary issued in 1692 The word is attested in Old Khanty language пелки (pelki) 'half' in a given name which is nowadays considered archaic and the word consequently is obsolete. The contemporary Khanty term is "пелəк (pelək)" half. Another inscription on a mordovka was in Old Erzya in the same script with the similar meaning.
Triangle Moksha coins
Zavariukhin describes as well 22x23 mm size triangle form silver coins with obverse featured a woman's bust. Those coins first were described by Vladimir Aunovsky in 1869, he reports they are used in traditional Moksha woman's headdress decoration and they say that was their queen depiction, meaning princess Narchat.
Bracteates
Evgeny Arsiukhin describes his collection from Chuvashia and divides his corpus into complex 1 and complex 2. Complex 1 is a 2001 hidden treasure assemblage found in Chuvashia includes mordovkas and Ruthenian coins. Complex 2 is a collection of coins from old Chuvashian used before as a decoration. Complex 1 with Ф-tamga include a bracteate with "Cyrillic inscription in 18th century manner". Spassky previously pointed out at huge amount of false coins in Muscovy mint but this type bracteate seems to be formed much earlier, between 1547 and 1565.
See also
Narchat
Mukhsha
Mukhsha Ulus
References
Bibliography
Mashkov V.V. Monety vostochno-slavianskogo prigranichya. Yekaterinburg, SV-96, 1998, pp. 234–235
Nesterov I. V. Mordovki - padcheritsy russkoy monetnoy sistemy. Faizkhanovskiye chtenia. Materials of 5th annual scientific and practical conference. Moscow, Nizhny Novgorod, 2009
Zverev S.V. Printsipy formirovania tipov podrazhatelnykh monet Kazanskogo khanstva. Ob izobrazheniyakh na mordovkakh. Sovetsky kollektsioner. Moscow, 1991. No 28
Denominations (currency)
Coins of Russia
Silver coins
Obsolete units of measurement
Medieval currencies | Mordovka | [
"Mathematics"
] | 1,120 | [
"Obsolete units of measurement",
"Quantity",
"Units of measurement"
] |
70,117,801 | https://en.wikipedia.org/wiki/Zwackhiomyces%20parmotrematis | Zwackhiomyces parmotrematis is a species of lichenicolous fungus in the family Xanthopyreniaceae. Found in Suriname, it was formally described as a new species in 2018 by Dutch lichenologist Pieter van den Boom. The type was collected west of Groningen (Saramacca District) in an abandoned Citrus orchard. Here it was found growing on the thallus of Parmotrema praesorediosum. The fungus does not cause visible damage to its host, such as discolouration or the formation of galls; rather, it produces tiny (50–100 μm diameter) black, spherical perithecia that are immersed in the host thallus. The specific epithet parmotrematis refers to the genus of its host lichen.
References
Xanthopyreniaceae
Fungi described in 2018
Fungi of South America
Lichenicolous fungi
Fungus species | Zwackhiomyces parmotrematis | [
"Biology"
] | 188 | [
"Fungi",
"Fungus species"
] |
70,120,049 | https://en.wikipedia.org/wiki/CASS%20microscopy | CASS is an acronym of Collective Accumulation of Single Scattering. This technique collects faint single scattering signal among the intense multiple scattering background in biological sample, thereby enabling conventional diffraction-limited imaging of a target embedded in a turbid sample.
Principle
CASS microscopy makes use of time-gated detection and spatial input-output wave correlation. Theoretical description is given below.
Input-Output Relationship for a given Object Function
Let be a planar object function that we wish to reconstruct. Then, it is related to its Fourier transform by
where represents a 2-dimensional wavevector.
Now, let's take a look at the relation between input and output wave in reflection geometry.
where we assumed the incoming wave is plane wave.
Then, the angular spectrum of the output field with given input field is
where has been used.
Coherent Addition
Now, consider a reflection matrix in wavevector space without aberration.
where explains the attenuation of single-scattered wave, and explains the attenuation of the time-gated multiple-scattered waves.
With , total summation of output field over all possible input wavevector becomes:
from which we observe that single-scattered field adds up coherently with the increasing number of incoming wavevectors, whereas the multiple-scattered field adds up incoherently.
Accordingly, the output intensity behaves as follows with the number of incoming wavevector N
Comparison to Confocal Microscopy
CASS microscopy has a lot in common with confocal microscopy which enables optical sectioning by eliminating scattered light from other planes by using a confocal pinhole. The main difference between these two microscopy modality comes from whether the basis of illumination is in position space or in momentum space. So, let us try to understand the principle of confocal microscopy in terms of momentum basis, here.
In confocal microscopy, the effect of the pinhole can be understood by the condition that for all possible input wavevector 's, where it is assumed that illumination is focused at .
The resulting field from confocal microscopy (CM) then becomes
where N refers to the number of possible input wavevector 's.
The formula above gives for the case of .
Application
Rat brain imaging through skull
CASS microscopy has been used to image rat brain without removing skull. It has been further developed such that light energy can be delivered on the target beneath the skull by using reflection eigenchannel, and about 10-fold increase in light energy delivery has been reported.
References
Microscopy | CASS microscopy | [
"Chemistry"
] | 508 | [
"Microscopy"
] |
70,121,241 | https://en.wikipedia.org/wiki/Alterococcus%20agarolyticus | Alterococcus agarolyticus is a Gram-negative, facultatively anaerobic, halophilic and thermophilic bacterium from the genus of Alterococcus.
References
Verrucomicrobiota
Bacteria described in 1999 | Alterococcus agarolyticus | [
"Biology"
] | 53 | [
"Bacteria stubs",
"Bacteria"
] |
70,121,302 | https://en.wikipedia.org/wiki/Prosthecobacter%20algae | Prosthecobacter algae is a Gram-negative, facultatively anaerobic and fusiform-shaped bacterium from the genus Prosthecobacter which has been isolated from activated sludge.
References
Verrucomicrobiota
Bacteria described in 2014 | Prosthecobacter algae | [
"Biology"
] | 59 | [
"Bacteria stubs",
"Bacteria"
] |
70,121,475 | https://en.wikipedia.org/wiki/Lentimonas | Lentimonas is a bacterial genus from the family of Puniceicoccaceae with one known species (Lentimonas marisflavi).
See also
List of bacterial orders
List of bacteria genera
References
Bacteria genera
Monotypic bacteria genera
Taxa described in 2010
Verrucomicrobiota | Lentimonas | [
"Biology"
] | 59 | [
"Bacteria stubs",
"Bacteria"
] |
70,123,605 | https://en.wikipedia.org/wiki/Normal%20distributions%20transform | The normal distributions transform (NDT) is a point cloud registration algorithm introduced by Peter Biber and Wolfgang Straßer in 2003, while working at University of Tübingen.
The algorithm registers two point clouds by first associating a piecewise normal distribution to the first point cloud, that gives the probability of sampling a point belonging to the cloud at a given spatial coordinate, and then finding a transform that maps the second point cloud to the first by maximising the likelihood of the second point cloud on such distribution as a function of the transform parameters.
Originally introduced for 2D point cloud map matching in simultaneous localization and mapping (SLAM) and relative position tracking, the algorithm was extended to 3D point clouds and has wide applications in computer vision and robotics. NDT is very fast and accurate, making it suitable for application to large scale data, but it is also sensitive to initialisation, requiring a sufficiently accurate initial guess, and for this reason it is typically used in a coarse-to-fine alignment strategy.
Formulation
The NDT function associated to a point cloud is constructed by partitioning the space in regular cells. For each cell, it is possible to define the mean and covariance of the points of the cloud that fall within the cell. The probability density of sampling a point at a given spatial location within the cell is then given by the normal distribution
.
Two point clouds can be mapped by a Euclidean transformation with rotation matrix and translation vector
that maps from the second cloud to the first, parametrised by the rotation angles and translation components.
The algorithm registers the two point clouds by optimising the parameters of the transformation that maps the second cloud to the first, with respect to a loss function based on the NDT of the first point cloud, solving the following problem
where the loss function represents the negated likelihood, obtained by applying the transformation to all points in the second cloud and summing the value of the NDT at each transformed point . The loss is piecewise continuous and differentiable, and can be optimised with gradient-based methods (in the original formulation, the authors use Newton's method).
In order to reduce the effect of cell discretisation, a technique consists of partitioning the space into multiple overlapping grids, shifted by half cell size along the spatial directions, and computing the likelihood at a given location as the sum of the NDTs induced by each grid.
References
Sources
External links
Computer vision
Pattern matching | Normal distributions transform | [
"Engineering"
] | 496 | [
"Artificial intelligence engineering",
"Packaging machinery",
"Computer vision"
] |
70,123,962 | https://en.wikipedia.org/wiki/Reef%20burials | Reef burials are a type of "green" or "natural" burial considered by some to be an eco-friendly alternative to traditional burial. Cremation ash is mixed with concrete to form objects that are placed on the seafloor to encourage wildlife in areas where sea life has been diminished.
Background
Reef burials are a new burial practice gaining a degree of popularity. Rather than being buried in the earth, a person's remains are cremated and the resulting ash is mixed with pH-balanced concrete to create structures which are placed on the seabed to help restore marine habitats similar to a coral reef. The concrete is mixed using fibreglass rather than metal, so that it does not rust and has the same pH balance as the sea. In areas where the seafloor or coral reefs have been destroyed the structures help to renew the sea-life by establishing new habitats for fish and crustaceans. The structures are expected to last for 500 years and are variously perforated domes called "reef balls", pyramids, or similar memorial-style shapes chosen to be appropriate to the location. Reef balls weigh between and their perforations ensure that storm pressure doesn't move them out of place on the sea floor.
Reef burials are popular amongst divers and others who love the sea. Some people feel that such burials offer the deceased a second life as part of a living reef. Loved ones are given the GPS coordinates of the resting place so that they dive to visit the site of the remains. A memorial plaque is installed with the person's name, date of birth and death. Thousands of reef balls are put into oceans each year. Large reef memorials can accommodate multiple sets of remains, so that families can be included and placed together.
Locations
In the United States there are more than thirty permitted locations for reef memorials, including off the coasts of Florida at Mexico Beach, Egg Harbor, near Atlantic City, New Jersey and Texas. In the UK, where the Crown Estate owns the UK seabed, a square-kilometre site off the coast of Weymouth and Portland has been designated for this use in the 'Wreck to Reef' area, with a particular focus on creating structures to shelter young lobsters until their shells grow.
Artificial reef balls were first used at Jurien reef in Western Australia in 2015. In Bali, Resting Reef operates two memorial sites in areas severely affected by unsustainable fishing and coral mining. These reefs aim to restore marine ecosystems and create job opportunities for local residents.
In 2019, the first reef burials were placed in the water using a crane in the Venice lagoon in Italy.
Despite growing popularity, the process still involves both cremation and concrete, both of which carry an environmental cost. Cremation, depending on the age of the crematorium, releases around of and the concrete sector is responsible for 8 percent of global production.
Sea rewilding
Depending on the locations different varieties of coral can grow on the surface of the concrete and algae, diatoms, eels, fish and invertebrates will come to live on the structure. Each memorial contributes to a unique ecosystem and provides a permanent and environment for all marine life.
In the most established memorial reefs such as Neptune Memorial Reef, Florida, a marine study survey, estimated that the population numbers of wild sea life went from close to zero to thousands in the space of two years. The survey found spotted eagle rays, damsel fish and puffer fish. Since then the numbers have continued to grow: a survey in 2018 showed the reef supports more than 65 different fish, shrimp and lobster and 75 other species including sponges, and corals.
The structures created by Resting Reef in Bali play a key role in restoring diversity to degraded reefs. By offering a hard substrate for coral growth, they also provide refuge for small and juvenile reef fish, enhancing the overall health of the marine ecosystem. In Resting Reef’s first round of ecological monitoring in October 2024, after just 4 months since deployment their memorial reefs were found to be already providing habitats to 41 species of reef fish.
The Solace Reef in Weymouth Bay. England is seeded with baby lobsters.
See also
Reef Ball Foundation
Neptune Memorial Reef
Burial at sea
Sea rewilding
References
Burials at sea
Ceremonies
Coral reefs
Ecological restoration
Environmental conservation
Funerals
Reefs | Reef burials | [
"Chemistry",
"Engineering",
"Biology"
] | 864 | [
"Biogeomorphology",
"Ecological restoration",
"Coral reefs",
"Environmental engineering"
] |
47,413,207 | https://en.wikipedia.org/wiki/Visible%20Multi%20Object%20Spectrograph | The Visible Multi-Object Spectrograph (VIMOS) is a wide field imager and a multi-object spectrograph installed at the European Southern Observatory's Very Large Telescope (VLT), in Chile. The instrument used for deep astronomical surveys delivers visible images and spectra of up to 1,000 galaxies at a time. VIMOS images four rectangular areas of the sky, 7 by 8 arcminutes each, with gaps of 2 arcminutes between them. Its principal investigator was Olivier Le Fèvre.
The Franco-Italian instrument operates in the visible part of the spectrum from 360 to 1000 nanometers (nm). In the conceptual design phase, the multi-object spectrograph then called VIRMOS included an additional instrument, NIMOS, operating in the near-infrared spectrum of 1100–1800 nm.
Operating in the three different observation modes, direct imaging, multi-slit spectroscopy, and integral field spectroscopy, the main objective of the instrument is to study the early universe through massive redshift surveys, such as the VIMOS-VLT Deep Survey.
VIMOS saw its first light on 26 February 2002, and has since been mounted on the Nasmyth B focus of VLT's Melipal unit telescope (UT3).
It was retired in 2018 to make space for the return of CRIRES+.
Gallery
See also
List of instruments at the Very Large Telescope
References
Astronomical instruments
Telescope instruments
Spectrographs
2002 introductions
2002 establishments in Chile | Visible Multi Object Spectrograph | [
"Physics",
"Chemistry",
"Astronomy"
] | 303 | [
"Telescope instruments",
"Spectrum (physical sciences)",
"Spectrographs",
"Astronomical instruments",
"Spectroscopy"
] |
47,413,780 | https://en.wikipedia.org/wiki/Anna%20Akhmanova | Anna Sergeevna Akhmanova (born 11 May 1967) is a Russian-born professor of Cell Biology at Utrecht University in the Netherlands. She is best known for her research regarding microtubules and the proteins, called TIPs, that stabilize one specific end of the tubules. Among the awards she has won, she was one of the recipients of the 2018 Spinoza Prize, the highest honor for Dutch scientists.
Biography
Anna Akhmanova was born on 11 May 1967 in Moscow, Russia, to a family of scientists. Her grandmother was an English and linguistics professor, her father a physics professor, and her mother and now her brother hold PhDs in physics as well. She cites an interest in nature from an early age and that "a career in science was a very natural choice" for herself. She attended Moscow State University, where she studied biology in the country's then-standard five-year program to receive her masters. During this program she studied basic biology, along with cell biology and biochemistry. Her fifth-year research thesis was completed in Alexander Mankin's laboratory where she researched halophilic archaebacteria; she credits Mankin as the person from whom she learned most of her molecular biology knowledge. She received her master's degree in 1989.
After graduating from Moscow State, Akhmanova left Russia to continue her studies in the Netherlands. She had originally looked for doctorate programs in Russia, but however, "the salaries were very low, there was absolutely no funding to do research, and the country as a whole was experiencing problems." During this time, the Soviet policy of perestroika was negatively affecting the university and research programs there, which led to Akhmanova's decision to go to the Netherlands with her young daughter to obtain her PhD. There, she worked at Radboud University Nijmegen (RU) in a lab under Wolfgang Hennig; her research then focused on obtaining mutants of histone genes. She received her PhD in 1997 from RU.
She completed two postdoctoral projects, the first of which was at RU, where she worked with anaerobic organisms for the Department of Microbiology. Her second postdoc was done at the Erasmus University of Rotterdam. She worked in Niels Galjart's lab in the Department of Cell Biology which Frank Grosveld headed; her research focused on gene regulation and transcription. She worked with one transcription factor using two-hybrid screening and was asked by Casper Hoogenraad for help with screening CLIP-115, a microtubule-binding protein that Hoogenraad was working with. Akhmanova and Hoogenraad then created clones for the proteins CLASP and Bicaudal-D, which Akhmanova describes as the proteins that defined her career.
In 2011, Akhmanova and Hoogenraad continued to collaborate on research and moved their laboratories to Utrecht University, where they began running the Division of Cell Biology. , she is still a cell biology professor at Utrecht University, where she continues to do research on intracellular transportation, especially involving microtubule proteins.
Research
Akhmanova and her team study the cell cytoskeleton and its effect on human diseases, cell polarization, and vertebrate development. Their main focus is on the microtubules that form part of the cytoskeleton and are essential for many processes, especially cell division. Their research is important for battling disease processes such as cancer, neurodegeneration, and the spread of pathogens throughout the cell.
In terms of methods, the team uses high resolution images of the cells they are studying. They utilize specific assays to measure protein dynamics, reconstitute cytoskeleton processes in vitro, and identify the interactions of different proteins.
The team studies specific proteins that interact on the plus and minus ends of the microtubules, specifically the plus end tracking proteins (+TIPs), which associate with the plus end of the microtubule to regulate its dynamics, and how the +TIPs interact with other structures in the cell. More recently, they have started researching "the biochemical properties and functional roles of the proteins" which organize minus end tracking proteins (-TIPs).4 There is far less information about –TIPs, and they are still not fully understood; however, recent research on CAMSAP, a type of –TIP, has shown that it plays an important role for organizing and stabilizing microtubules during interphase. Akhmanova's group now focus on finding how CAMSAP contributes to the organization and stabilization of non-centrosomal microtubules during cell division.
Another of their projects concerns the mechanisms involved in microtubule-based vesicle transport. They identified several structures that link the microtubule motors, kinesin and dynein, to vesicles, and they developed procedures to show the function of the linkers when gathering motor proteins to associate with membrane organelles. Inside the cell, kinesin and dynein protein motors are required for long-range transport along microtubules. Akhmanova's team focuses mainly on dynein, the motor that moves toward the minus end of the microtubule, and how it is linked to the various organelles and vesicles it transfers. They also study how dynein coordinates with kinesin, the motor that moves toward the plus end of the microtubule, when they are attached to the same organelle or vesicle, and they study the different signaling pathways that affect these motors. As of 2016, they were examining the protein Bicaudal D and its role in dynein-dependent transport, as it has been found to be important for dynein-dependent transport of mRNA in flies and of exocytotic vesicles in mammals. Bicaudal D was also found to be important for the positioning of the centrosomes and nucleus during mitosis, as the positioning is facilitated by dynein and kinesin.
Akhmanova and her team use constitutive exocytosis as a model system for their study of kinesin and dynein. Exocytotic carriers move from the Golgi to the plasma membrane along microtubules. The team has found that the same cortical complexes are used to attach the microtubule to the plasma membrane as are used to attach them to vesicles. From here, the team plans to study how the cortical complexes are made and regulated, how they affect the attachments and dynamics of microtubules, and what the mechanism is that allows them to fuse vesicles. Also, they would like to find more information on the NF-κB signaling pathway as it was found to have proteins, called ELKS, which are found in the cortical complex. They plan to research how the pathway's components interact and how it affects microtubule stabilization and vesicle fusion.
Honours and awards
Akhmanova has received several awards, including the NWO Spinoza Prize in 2018, the ALW Vernieuwingsimpuls VIDI award in 2001, and the VICI award in 2007. In 2013, she and her colleague Marileen Dogterom received a European Research Council Synergy grant of 7.1 million euro. The grant was given for research on cell division and cell movement.
Akhmanova is a member of the European Molecular Biology Organization (2010) and the Royal Netherlands Academy of Arts and Sciences (2015), and she is the chair of the board for the Netherlands Society for Microscopy. She is also on the editorial board for various publications such as eLife, Journal of Cell Science, BMC Cell Biology, The Journal of Biological Chemistry, Traffic, and BioArchitecture.
Listed are some of her awards:
2001 – VIDI award, ALW Vernieuwingsimpuls
2007 – VICI award, ALW Vernieuwingsimpuls
2014 – Synergy grant, European Research Council
2018 – Spinoza Prize, Netherlands Organisation for Scientific Research
References
External links
Profile at Utrecht University
Profile on NARCIS
1967 births
Living people
21st-century Russian biologists
Cell biologists
Dutch molecular biologists
Members of the European Molecular Biology Organization
Members of the Royal Netherlands Academy of Arts and Sciences
Molecular biologists
Moscow State University alumni
Scientists from Moscow
Radboud University Nijmegen alumni
Soviet emigrants to the Netherlands
Spinoza Prize winners
Academic staff of Utrecht University
Women molecular biologists | Anna Akhmanova | [
"Chemistry"
] | 1,736 | [
"Molecular biologists",
"Biochemists",
"Molecular biology"
] |
47,414,167 | https://en.wikipedia.org/wiki/Desi%20daru | Desi daru (), also known as country liquor or Indian-made Indian liquor (IMIL), is a local category of liquor produced on the Indian subcontinent, as opposed to Indian-made foreign liquor. Due to cheap prices, country liquor is the most popular alcoholic beverage among the impoverished people. It is fermented and distilled from molasses, a by-product of sugarcane. Desi liquor is a broad term and it can include both legally and illegally made local alcohol. The term desi daru usually refers to legal alcohol while other types of country liquor (arrack and palm toddy) may be categorised as moonshine alcohol.
Etymology
The term desi, from Hindi language term desh (country or region), which is generally an endonym for the compatriot or local is often applied to food or drink that is considered traditional or native. Dārū (Hindi दारू and Urdu دارو) is a Persian-derived term used for any alcoholic beverage in India. Śarāb (Hindi शराब and Urdu شراب) is another Persian-derived equivalent and is used in some areas with less frequency.
Industry
An article in the medical journal The Lancet estimated that nearly two-thirds of the alcohol consumed in India is country liquor. Globus spirits mentioned that India's country liquor market is about 242 million cases (over 30% of the beverage industry in India) with a growth rate of about 7% per annum. No data regarding Pakistan is available as drinking alcohol is officially prohibited for Muslims in Pakistan, although locally made liquor is sold on the black market.
Government regulation provide for a separate licensing for production, distribution and retailing of country liquor (IMIL) as opposed to Indian-made foreign liquor.
Social issues
Country liquor, being the cheapest alcohol in India, is the mainstay alcoholic beverage for the rural population and urban poor. In rural areas, illicit country liquor has been blamed for domestic violence and poverty in the family. There have been several protests against country liquor shops/bars in villages.
Adulteration
As country liquor is cheaper than other spirits, there have been reports of mixing country liquor with Scotch/English whisky in many bars in India.
If care is not taken in the distillation process and the proper equipment is not used, harmful impurities such as fusel alcohols, lead from plumbing solder, and methanol can be concentrated to toxic levels. Several deaths have been reported in India and Pakistan due to consumption of non-factory made toxic liquor.
In popular culture
There are several references of desi daru in Bollywood films, songs.
2012 film Cocktail has song named Daru Desi sung by Benny Dayal and Shalmali Kholgade.
2011 film F.A.L.T.U has party song named Char Baj Gaye (Party Abhi Baaki Hai) has reference of desi daru.
Scenes in 2011 film Rockstar shows lead actor Ranbir Kapoor and lead actress Nargis Fakhri drinking desi daru.
2014 film Main Aur Mr. Riight has song named Desi Daru sung by Jasbir Jassi.
See also
Alcoholic Indian beverages
Beer in India
Indian-made foreign liquor
Indian whisky
Lion beer, Asia's first beer brand
Solan No. 1, India's first malt whisky
Old Monk, iconic Indian rum
Sura
Other India alcohol related
Alcohol laws of India
Alcohol prohibition in India
Dry Days in India
References
External links
Photo of Desi daru by ''Firstpost
Indian alcoholic drinks
Indian distilled drinks
Desi cuisine
Desi culture
Traditional Indian alcoholic beverages
Adulteration | Desi daru | [
"Chemistry"
] | 751 | [
"Adulteration",
"Drug safety"
] |
47,415,993 | https://en.wikipedia.org/wiki/Water%20gel%20explosive | A water-gel explosive is a fuel-sensitized explosive mixture consisting of an aqueous ammonium nitrate solution that acts as the oxidizer. Water gels that are cap-insensitive are referred to under United States safety regulations as blasting agents. Water gel explosives have a jelly-like consistency and come in sausage-like packing stapled shut on both sides.
Water-gel explosives have almost completely displaced dynamite, becoming the most-used civil blasting agents.
Composition
Water gels usually have many different ingredients. They contain a gelatinizing agent, also known as a thickener, that modifies their consistency, ranging from easily pourable gels to hard solids. Polyvinyl alcohol, guar gum, dextran gums, and urea-formaldehyde resins are the typical gelling agents. Guar, specifically, is a gelling agent used for the aqueous portion of the water gel explosives. The primary component of water gels is methylamine nitrate. Methylamine nitrate is the salt formed by the neutralization of methylamine with nitric acid. Water gel explosives are also made of ammonium nitrate, calcium nitrate, aluminum, ethylene glycol and TNT. The proportions of these components vary depending on the desired explosiveness of the water gel.
Preparation
Water gel explosives are produced by combining nitroparaffins, usually nitromethane, with an aqueous salt solution and a gelling agent. These nitroparaffins typically make up most of the water gel explosive. Different types of gelling agents are used to create the water gel explosive. One agent is insoluble in water, but able to gel with nitromethane. The gel used for nitromethane is cyanoethylether, a derivative of galactomannan gum. Other agents are water-soluble and are used for the aqueous salt solution. As mentioned above, water-soluble gums and gel modifiers (like guar) can be used for the gelling of aqueous solutions. When the salt solution and nitroparaffin are gelled, the entire mixture is combined and mixed together until the desired consistency is achieved. One characteristic that allows the explosive to work so well is the insoluble nature of the nitroparaffin. The effectiveness of the water gels is dependent on the dissemination of salts in the salt solution. The particles need to be very small and fine so that they can be dispersed well throughout the solution. Some salts that are commonly used include: ammonium nitrate, sodium nitrate, sodium perchlorate and potassium chlorate. The sensitivity of the explosive must be increased in order to improve the initiation of the detonation of the explosive. There are different techniques for increasing the sensitivity. Aluminum or other powdered metals can help increase the sensitivity of the water gel, but increasing the sensitivity also means that the explosives are more combustible. Powdered metals have not proven to be completely effective in increasing the sensitivity of the explosive because they do not uniformly mix through the solution. They also lose sensitivity as storage time increases. Liquid non-self-explosive sensitizers like nitrobenzene and liquid nitrotoluene have not worked well either because they are difficult to hold in suspension. Liquid aliphatic mononitrates have been found to work very effectively as sensitizers when they are well mixed in the water gel.
Advantages and uses
Water gel explosives tend to be less toxic and are less hazardous than dynamite to manufacture, transport, and store. Water gels are also less expensive than conventional explosives. Because they are relatively safe and easy to use, they are often used in the mining industry. There are many different types of water gel explosives for use in different situations. One type, a small diameter slurry explosive, can be used specifically for blasting in coal undercut, midcut, and depillaring areas. They are preferable to nitroglycerin-based explosives like dynamite because they produce less noxious fumes. Detagel, which is very high in strength, is a specific example of a small diameter water gel explosive that is used for mining activities.
Water gel explosives are frequently used as cartridge explosives because they are much easier to load into large casings. With water gel explosives, the slurry material can simply be poured into the casing. Traditional explosives are cast into the casing. This process is laborious and the charge may begin to shrink, creating multiple voids. A final advantage of slurry is that it can be stored in non-explosive component form and sensitized into field-manufactured explosive as it is needed. The explosive may be sensitized by the addition of gas, metal powder, or another explosive such as TNT, RDX, HMX, or PETN. The water in water gel explosives is converted into a reactant by the addition of large amounts of aluminum.
References
Explosives | Water gel explosive | [
"Chemistry"
] | 1,016 | [
"Explosives",
"Explosions"
] |
47,419,016 | https://en.wikipedia.org/wiki/International%20Journal%20of%20Multiphase%20Flow | The International Journal of Multiphase Flow is a monthly peer-reviewed scientific journal covering fluid mechanics. The editors-in-chief are Alfredo Soldati (TU Wien) and S. Balachander (U Florida). The founding editor was Gad Hetsroni (Technion – Israel Institute of Technology). Previous editor (2007-2017) was Andrea Prosperetti (U Houston).
According to the Journal Citation Reports, the journal has a 2020 impact factor of 3.186.
References
External links
Fluid dynamics journals
Academic journals established in 1973
Elsevier academic journals
Monthly journals
English-language journals | International Journal of Multiphase Flow | [
"Chemistry"
] | 124 | [
"Fluid dynamics journals",
"Fluid dynamics stubs",
"Fluid dynamics"
] |
47,420,735 | https://en.wikipedia.org/wiki/VVVVID | VVVVID (pronounced vid) is an Italian video on demand service and a virtual community, with an offering that includes international movies, anime, series, music videos, and short thematic videos. VVVVID's service is free of charge and available exclusively in Italy on the Web and via dedicated apps for iPad and for Android smartphones and tablets. Registration is required.
In December 2014, for the first time in Italy, VVVVID has streamed the Italian dubbed version of the Japanese animated series Tokyo Ghoul, without any previous airing on traditional TV, followed in July 2015 with Tokyo Ghoul √A, in January 2016 by One-Punch Man and Prison School, and in October 2016 by Tokyo Ghouls 2 OVA and All Out!!, in December 2016 by Parasyte and Death Parade, in June 2017 by The Dragon Dentist, in July 2017 by Drifters and the last 6 episodes of Hellsing Ultimate, in October 2017 by Fate/stay night: Unlimited Blade Works and the second season of Attack on Titan. In May 2018, Kill La Kill premiered on the platform, followed by My Hero Academia in August 2018. January 2020 saw the Italian-dubbed premiere of Demon Slayer: Kimetsu no Yaiba. In winter of the same year, they stream Magia Record.
As of 23 July 2024, the platform is not listed on search engines anymore and is allegedly in maintenance.Fears have been expressed by users and past collaborators that this could be a prelude to a definitive closure.
See also
Digital television
References
External links
Official website
Recommender systems
Italian entertainment websites
Video on demand services | VVVVID | [
"Technology"
] | 331 | [
"Information systems",
"Recommender systems"
] |
47,421,364 | https://en.wikipedia.org/wiki/Ecomodernism | Ecomodernism is an environmental philosophy which argues that technological development can protect nature and improve human wellbeing through eco-economic decoupling, i.e., by separating economic growth from environmental impacts.
Description
Ecomodernism embraces substituting natural ecological services with energy, technology, and synthetic solutions as long as they help reduce impact on environment.
Among other things, ecomodernists embrace high-tech farming techniques to produce more food using less land and water, thus freeing up areas for conservation (precision agriculture, vertical farming, regenerative agriculture and genetically modified foods) and cellular agriculture (cultured meat) and alternative proteins, fish from aquaculture farms, desalination and water purification technologies, advanced waste recycling and circular economy, sustainable forestry and ecological restoration of natural habitats and biodiversity which includes a wide scope of projects including erosion control, reforestation, removal of non-native species and weeds, revegetation of degraded lands, daylighting streams, the reintroduction of native species (preferably native species that have local adaptation), and habitat and range improvement for targeted species, water conservation, Building Information Modeling in green building, green building and green infrastructure, smart grids, resource efficiency, urbanization, smart city, urban density and verticalization, adoption of electric vehicles and hydrogen vehicles, reusable drone light shows, projection mapping and 3D holograms to provide safer and ‘greener’ alternatives to traditional fireworks, automation, carbon capture and storage and direct air capture, green nanotechnology (nanofilters for water purification, nanomaterials for air pollution control, nanocatalysts for more efficient chemical processes, nanostructured materials for improved solar cells, nanomaterials for enhancing battery performance, nanoparticles for soil and groundwater remediation and nanosensors for detecting pollutants), energy storage technologies, alternative materials such as bioplastics and bio-based materials and high-tech materials such as graphene and carbon fibers, clean energy transition i.e. replacing low power-density energy sources (e.g. firewood in low-income countries, which leads to deforestation) with high power-density sources as long as their net impact on environment is lower (nuclear power plants, and advanced renewable energy sources), artificial intelligence for resource optimization (predictive maintenance in industrial settings to reduce waste, optimized routing for transportation to reduce fuel consumption, AI-driven climate modeling for better environmental predictions and supply chain optimization to reduce transportation emissions), climate engineering, synthetic fuels and biofuels, 3D printing, 3D food printing, digitalization, miniaturization, servitization of products and dematerialization. Key among the goals of an ecomodern environmental ethic is the use of technology to intensify human activity and make more room for wild nature.
Debates that form the foundation of ecomodernism were born from disappointment in traditional organizations who denied energy sources such as nuclear power, thus leading to an increase of reliance of fossil gas and increase of emissions instead of reduction (e.g. Energiewende). Coming from evidence-based, scientific and pragmatic positions, ecomodernism engages in the debate on how to best protect natural environments, how to accelerate decarbonization to mitigate climate change, and how to accelerate the economic and social development of the world's poor. In these debates, ecomodernism distinguishes itself from other schools of thought, including ecological economics, degrowth, population reduction, laissez-faire economics, the "soft energy" path, and central planning. Ecomodernism draws on American pragmatism, political ecology, evolutionary economics, and modernism. Diversity of ideas and dissent are claimed values in order to avoid the intolerance born of extremism and dogmatism.
Ecomodernist organisations have been established in many countries, including Germany, Finland, and Sweden. While the word 'ecomodernism' has only been used to describe modernist environmentalism since 2013, the term has a longer history in academic design writing and Ecomodernist ideas were developed within a number of earlier texts, including Martin Lewis's Green Delusions, Stewart Brand's Whole Earth Discipline and Emma Marris's Rambunctious Garden. In their 2015 manifesto, 18 self-professed ecomodernists—including scholars from the Breakthrough Institute, Harvard University, Jadavpur University, and the Long Now Foundation—sought to clarify the movement's vision: "we affirm one long-standing environmental ideal, that humanity must shrink its impacts on the environment to make more room for nature, while we reject another, that human societies must harmonize with nature to avoid economic and ecological collapse."
An Ecomodernist Manifesto
In April 2015, a group of 18 self-described ecomodernists collectively published An Ecomodernist Manifesto.
Reception and criticism
Some environmental journalists have praised An Ecomodernist Manifesto. At The New York Times, Eduardo Porter wrote approvingly of ecomodernism's alternative approach to sustainable development. In an article titled "Manifesto Calls for an End to 'People Are Bad' Environmentalism", Slate's Eric Holthaus wrote "It's inclusive, it's exciting, and it gives environmentalists something to fight for for a change." The science journal Nature editorialized the manifesto.
Ecomodernism has been criticized for inadequately recognizing what Holly Jean Buck, Assistant Professor of Environment and Sustainability, says is the exploitative, violent and unequal dimensions of technological modernisation. Sociologist Eileen Crist, Associate Professor Emerita, observed that ecomodernism is founded on a western philosophy of humanism with no regard to "nonhuman freedoms". Of the Manifesto Crist says Human Geographer Rosemary-Claire Collard and co-authors assert that ecomodernism is incompatible with neoliberal capitalism, despite the philosophy's claims to the contrary. By contrast, in his book "Ecomodernism: Technology, Politics and the Climate Crisis" Jonathan Symons argues that ecomodernism belongs in the social democratic tradition, promoting a third way between laissez-faire and anti-capitalism, and calling for transformative state investments in technological transformation and human development. Likewise, in "A sympathetic diagnosis of the Ecomodernist Manifesto", Paul Robbins and Sarah A. Moore describe the similarities and points of departure between ecomodernism and political ecology.
Another major strand of criticism towards ecomodernism comes from proponents of degrowth or the steady-state economy. Eighteen ecological economists published a long rejoinder titled "A Degrowth Response to an Ecomodernist Manifesto", writing "the ecomodernists provide neither a very inspiring blueprint for future development strategies nor much in the way of solutions to our environmental and energy woes."
At the Breakthrough Institute's annual Dialogue in June 2015, several environmental scholars offered a critique of ecomodernism. Bruno Latour argued that the modernity celebrated in An Ecomodernist Manifesto is a myth. Jenny Price argued that the manifesto offered a simplistic view of "humanity" and "nature", which she said are "made invisible" by talking about them in such broad terms.
The Ecomodernist philosophy invites a very techno-optimistic outlook towards the environment and in the “Techno-Optimist Manifesto” a 2023 self-published essay by venture capitalist Marc Andreessen states that many significant problems of humanity have been solved with the development of technology, particularly technology without any constraints, and that we should do everything possible to accelerate technology development and advancement. The philosophy from Ecomodernist Manifesto stresses on the viewpoint that climate change and other global ecological challenges are not the most important immediate concerns for the majority of the world’s people. So the richer and more urbanised nations become, the less their people care about their environmental impact, notes George Monbiot in the article "Meet the ecomodernists: ignorant of history and paradoxically old-fashioned". So, ‘Limits, ecomodernism and degrowth’ that the concern is more dependent on a modernist ‘fix’ mentality that searches for salvation in technology, Giorgos Kallis says.
In this very techno-optimist nature, the ecomodernist are decoupling humans from nature and the dependence upon it. But there is a risk here of what Rob Wallace calls ‘red washing capital’: justifying real-existing technologies and the relations that produce them, with the excuse that in some undefined future, a hypothetical socialism could put them to good use.
While ecomodernists see human technology as capable of transcending ecological and energetic limits, Clive Hamilton in his “Growth Fetish” mentions this ideology as the essential for the reproduction of the capitalist system, one that perpetuates and reproduces the unequal relations of exchange and enables the international capitalist class to capture embodied labor and energy in pursuit of accumulation and growth. This is also not very far away from Chris Smaje’s argument published on the Dark Mountain website, “modernisation” of the kind they celebrate may have liberated many people from bondage, oppression and hard labour, but it has also subjected many to the same forces. Cindy Isenhour in her article “Ecomodernism and contrasting definitions of technological progress in the Anthropocene” mentions that perhaps the contemporary moment calls for a reconceptualization of progress, one that recognizes the capacity of technology to mystify unequal relations of exchange and the shifting of environmental burdens in a highly unequal global society.
See also
Bright green environmentalism
Earthship
Ecological civilization
Ecological modernization
Environmental technology
Reflexive modernization
Solarpunk
Technogaianism
Utopian architecture
Nuclear power proposed as renewable energy
References
External links
Bright green environmentalism
Environmentalism
Environmental social science concepts
Environmental philosophy | Ecomodernism | [
"Environmental_science"
] | 2,027 | [
"Environmental social science concepts",
"Environmental philosophy",
"Environmental social science"
] |
47,422,135 | https://en.wikipedia.org/wiki/Ernst%20K.%20Zinner | Ernst Kunibert Zinner (30 January 1937 – 30 July 2015) was an Austrian astrophysicist, known for his pioneering work in the analysis of stardust in the laboratory. He long had a position in the United States at the Laboratory for Space Physics (later part of the McDonnell Center for the Space Sciences) at Washington University in St. Louis, Missouri, where he had earned his doctorate. He came to the United States in the 1960s for graduate work. In addition, Zinner regularly taught at European universities, and other American institutions.
Personal life
Zinner was born on 30 January 1937 at Steyr, Austria, a small town about 100 miles west of Vienna. Although his father, Kunibert Zinner, was a renowned sculptor, Ernst was more interested as a boy in nature and science. Zinner's four younger siblings, and other relatives, live in Austria.
While on sabbatical later in his career, he met Brigitte Wopenka, a faculty member of the Institute of Analytical Chemistry in Vienna. She returned with him to the United States and they married in 1980. They had a son, Max Giacobini Zinner. The son now lives in New York City.
Education and career
Zinner obtained an undergraduate degree in physics from the Vienna University of Technology and started working. In the mid-1960s, he moved to St. Louis, Missouri to attend Washington University for graduate work. He earned his Ph.D. there in 1972 in high energy physics.
That year he was invited by Robert M. Walker to work at the Laboratory for Space Physics (later part of the McDonnell Center for the Space Sciences) at Washington University.
He also held positions at:
Max Planck Institute for Nuclear Physics (1980)
Vienna University of Technology (1980–82)
University of Pavia (1989)
University of Bern (1994)
Australian National University (1995)
Max Planck Institute for Chemistry (2001, 03, 04)
National Museum of Natural History (France) (2006)
Carnegie Institution for Science (2010)
University of Perugia (2011)
University of Granada (2013)
Zinner continued to work at the McDonnell Center for the Space Sciences for the rest of his career, in 1989 being named as a Research Professor of Physics and Earth and Planetary Sciences. He retired early in 2015.
Zinner was a member of the American Association for the Advancement of Science, the American Geophysical Union, and Sigma Xi. He was also a fellow of the American Physical Society, the Meteoritical Society, the Geochemical Society, and the European Association of Geochemistry.
Zinner had mantle cell lymphoma for the last 19 years of his life. He died on 30 July 2015 at the age of 78.
Research
Zinner's PhD research was in high energy physics. He subsequently studied the effects that the environment within the Solar System would have on the Moon and the parent bodies of meteors, using nuclear particle tracks, micrometeoid craters, and elements in the solar wind. His later research was focused on the information contained in presolar grains carried by early meteorites. These grains were formed in atmospheres and explosions of stars outside of the Solar System. They can provide information about the history of stellar nucleosynthesis and the formation of the Solar System.
Since 1974, Zinner's research has involved Ion microprobe analysis. He has worked with the Cameca IMS 3f instrument since 1982, and the Cameca NanoSIMS instrument since 2000. He led the Long Duration Exposure Facility. Zinner was instrumental in identifying, for the first time, material in meteorites that pre-dated the formation of the Solar System 4.6 billion years ago. Zinner and his colleagues found minute amounts of stardust - diamond and silicon carbide - that originated outside the solar system. Identification of these grains involved a measurement technique called secondary ion mass spectrometry (SIMS). Zinner and Ghislaine Crozaz expanded the use of SIMS to examine rare earth elements and applied this new technique to measure rare earth elements in thin sections of rocks and minerals.
Awards and honours
1987 Antarctic Service Medal, National Science Foundation
1997 J. Lawrence Smith Medal, National Academy of Sciences
1997 Leonard Medal of the Meteoritical Society
2010 Merle A. Tuve Fellow of the Carnegie Institution of Washington
2011 Fellow of the American Association for the Advancement of Science
Legacy
After his death, his family established an "Ernst Zinner Scholarship Fund" to support advanced cello students in the Community Music School at Webster University. Zinner had started learning cello at age 55, along with his son, then age 4.
References
1937 births
2015 deaths
Austrian physicists
Astrophysicists
Washington University in St. Louis physicists
Scientists from Missouri
Deaths from cancer in Missouri
Deaths from lymphoma in the United States
Washington University in St. Louis alumni
TU Wien alumni
Fellows of the American Physical Society | Ernst K. Zinner | [
"Physics"
] | 1,010 | [
"Astrophysicists",
"Astrophysics"
] |
47,422,895 | https://en.wikipedia.org/wiki/LogSumExp | The LogSumExp (LSE) (also called RealSoftMax or multivariable softplus) function is a smooth maximum – a smooth approximation to the maximum function, mainly used by machine learning algorithms. It is defined as the logarithm of the sum of the exponentials of the arguments:
Properties
The LogSumExp function domain is , the real coordinate space, and its codomain is , the real line.
It is an approximation to the maximum with the following bounds
The first inequality is strict unless . The second inequality is strict unless all arguments are equal.
(Proof: Let . Then . Applying the logarithm to the inequality gives the result.)
In addition, we can scale the function to make the bounds tighter. Consider the function . Then
(Proof: Replace each with for some in the inequalities above, to give
and, since
finally, dividing by gives the result.)
Also, if we multiply by a negative number instead, we of course find a comparison to the function:
The LogSumExp function is convex, and is strictly increasing everywhere in its domain. It is not strictly convex, since it is affine (linear plus a constant) on the diagonal and parallel lines:
Other than this direction, it is strictly convex (the Hessian has rank ), so for example restricting to a hyperplane that is transverse to the diagonal results in a strictly convex function. See , below.
Writing the partial derivatives are:
which means the gradient of LogSumExp is the softmax function.
The convex conjugate of LogSumExp is the negative entropy.
log-sum-exp trick for log-domain calculations
The LSE function is often encountered when the usual arithmetic computations are performed on a logarithmic scale, as in log probability.
Similar to multiplication operations in linear-scale becoming simple additions in log-scale, an addition operation in
linear-scale becomes the LSE in log-scale:
A common purpose of using log-domain computations is to increase accuracy and avoid underflow and overflow problems
when very small or very large numbers are represented directly (i.e. in a linear domain) using limited-precision
floating point numbers.
Unfortunately, the use of LSE directly in this case can again cause overflow/underflow problems. Therefore, the
following equivalent must be used instead (especially when the accuracy of the above 'max' approximation is not sufficient).
where
Many math libraries such as IT++ provide a default routine of LSE and use this formula internally.
A strictly convex log-sum-exp type function
LSE is convex but not strictly convex.
We can define a strictly convex log-sum-exp type function by adding an extra argument set to zero:
This function is a proper Bregman generator (strictly convex and differentiable).
It is encountered in machine learning, for example, as the cumulant of the multinomial/binomial family.
In tropical analysis, this is the sum in the log semiring.
See also
Logarithmic mean
Log semiring
Smooth maximum
Softmax function
References
Logarithms | LogSumExp | [
"Mathematics"
] | 646 | [
"E (mathematical constant)",
"Logarithms"
] |
49,177,869 | https://en.wikipedia.org/wiki/Reichardt%27s%20dye | Reichardt's dye (Betaine 30) is an organic dye belonging to the class of azomerocyanine betaines. This dye is notable for its solvatochromic properties, meaning it changes color depending on the solvent in which it is dissolved. It has one of the largest solvatochromic effects ever observed, with color varying across the entire visible spectrum. As a result, it gives striking visual results for chemical demonstrations.
This chemical is named for , who developed it when working as a doctoral student in the lab of . It is thus also sometimes called Dimroth–Reichardt dye. The names also sometimes refer to some close chemical analogs, in particular, the one having para substituted tert-butyl groups on the phenyl rings.
Synthesis
A newer synthesis is:
2,6-Diphenylphenol is nitrated with diluted nitric acid to 4-nitro-2,6-diphenylphenol and subsequently reduced with sodium dithionite to the amine. This is reacted in presence of sodium acetate in ethanol with 2,4,6-triphenylpyryliumhydrogensulfate to the hydrogen sulfate of the dye and the betaine is formed by adding sodium hydroxide.
References
Fluorescent dyes
Pyridinium compounds
Phenolates | Reichardt's dye | [
"Chemistry"
] | 278 | [
"Phenolates",
"Salts"
] |
49,178,109 | https://en.wikipedia.org/wiki/Poll%20%28Unix%29 | is a POSIX system call to wait for one or more file descriptors to become ready for use.
On *BSD and macOS, it has been largely superseded by kqueue in high performance applications. On Linux, it has been superseded by and .
See also
kqueue
epoll
inotify
select
References
External links
C POSIX library
Events (computing)
System calls
Unix | Poll (Unix) | [
"Technology"
] | 83 | [
"Information systems",
"Events (computing)"
] |
49,178,304 | https://en.wikipedia.org/wiki/Sarcodon%20quercinofibulatus | Sarcodon quercinofibulatus is a species of tooth fungus in the family Bankeraceae. Found in Spain, where it grows under Quercus petraea, it was described as new to science in 2011. The thick, fleshy caps of its fruit bodies are up to in diameter. The cap cuticle breaks up in age into concentric brown scales, revealing the cream-coloured brown flesh underneath. Spines on the underside of the cap are 5–8 mm long. They are initially cream, but become gray to grayish-brown in maturity. Application of a solution of potassium hydroxide turns the flesh grayish-green. The spores of S. quercinofibulatus are spherical, or nearly so, and typically measure 6.5–7.4 by 5.4–6.4 μm.
References
External links
Fungi described in 2011
Fungi of Europe
quercinofibulatus
Fungus species | Sarcodon quercinofibulatus | [
"Biology"
] | 188 | [
"Fungi",
"Fungus species"
] |
49,178,452 | https://en.wikipedia.org/wiki/Sarcodon%20rutilus | Sarcodon rutilus is a species of tooth fungus in the family Bankeraceae. Found in Papua New Guinea, it was described as new to science in 1974 by Dutch mycologist Rudolph Arnold Maas Geesteranus. The specific epithet rutilus refers to the red cap.
References
External links
Fungi described in 1974
Fungi of New Guinea
rutilus
Fungus species | Sarcodon rutilus | [
"Biology"
] | 76 | [
"Fungi",
"Fungus species"
] |
49,178,694 | https://en.wikipedia.org/wiki/Sarcodon%20wrightii | Sarcodon wrightii is a species of tooth fungus in the family Bankeraceae. It was first described in 1860 by Miles Berkeley and Moses Ashley Curtis as Hydnum wrightii. They were sent a specimen collected from Japan as part of the North Pacific Exploring and Surveying Expedition (1853–56). Rudolph Arnold Maas Geesteranus transferred it to the genus Sarcodon in 1967. The fungus produces roughly spherical spores that are tuberculate (covered in warts) and measure 5.5–6.5 by 4.5–5.5 μm.
References
External links
Fungi described in 1860
Fungi of Japan
wrightii
Taxa named by Miles Joseph Berkeley
Fungus species | Sarcodon wrightii | [
"Biology"
] | 138 | [
"Fungi",
"Fungus species"
] |
49,179,448 | https://en.wikipedia.org/wiki/Hydnellum%20joeides | Hydnellum joeides (the epithet is sometimes spelled ionides or jonides) is a species of tooth fungus in the family Bankeraceae.
Taxonomy
It was first described by Italian botanist Giovanni Passerini in 1872 as Hydnum joeides. Frédéric Bataille transferred it to the genus Sarcodon in 1924.
Description
The fungus makes fruit bodies with flattened to concave caps measuring in diameter. They initially have a velvety surface texture that later breaks up into reddish-brown scales. The crowded spines on the cap underside are up to 3 mm long, and are decurrent on the stipe. Initially pale pink, they become brownish in age. Spores are tuberculate (covered in warts), and measure 6.3–7.2 by 4–4.7 μm.
It is reportedly inedible.
Habitat and distribution
The fungus is found in western and central Europe, where it is an ectomycorrhizal symbiont of European beech (Fagus sylvatica), English oak (Quercus robur), and probably sessile oak (Quercus petraea). It is on the red lists of several countries: Flandres, France and Norway (critically endangered); The Netherlands, Germany, Lower Saxony and Switzerland (endangered); and Sweden (vulnerable). Because of the continued decline in sightings in Europe, it has been proposed for inclusion on the IUCN Red List of Threatened Species.
The species has also been reported from the United States, and New Zealand, although mycologist Eef Arnolds regards these records as doubtful because of discrepancies in the reported sizes of the spores.
References
External links
Fungi described in 1872
Fungi of Europe
joeides
Inedible fungi
Fungus species | Hydnellum joeides | [
"Biology"
] | 360 | [
"Fungi",
"Fungus species"
] |
49,182,345 | https://en.wikipedia.org/wiki/Marc%20Lackenby | Marc Lackenby is a professor of mathematics at the University of Oxford whose research concerns knot theory, low-dimensional topology, and group theory.
Lackenby studied mathematics at the University of Cambridge beginning in 1990, and earned his Ph.D. in 1997, with a dissertation on Dehn Surgery and Unknotting Operations supervised by W. B. R. Lickorish. After positions as Miller Research Fellow at the University of California, Berkeley and as Research Fellow at Cambridge, he joined Oxford as a Lecturer and Fellow of St Catherine's in 1999. He was promoted to Professor at Oxford in 2006.
Lackenby's research contributions include
a proof of a strengthened version of the 2 theorem on sufficient conditions for Dehn surgery to produce a hyperbolic manifold,
a bound on the hyperbolic volume of a knot complement of an alternating knot,
and a proof that every diagram of the unknot can be transformed into a diagram without crossings by only a polynomial number of Reidemeister moves. In February 2021 he announced a new unknot recognition algorithm that runs in quasi-polynomial time.
Lackenby won the Whitehead Prize of the London Mathematical Society in 2003.
In 2006, he won the Philip Leverhulme Prize in mathematics and statistics.
He was an invited speaker at the International Congress of Mathematicians in 2010.
Selected publications
References
External links
Home page
Year of birth missing (living people)
Living people
English mathematicians
Alumni of the University of Cambridge
Fellows of St Catherine's College, Oxford
Topologists
Whitehead Prize winners | Marc Lackenby | [
"Mathematics"
] | 308 | [
"Topologists",
"Topology"
] |
49,182,501 | https://en.wikipedia.org/wiki/Music%20technology | Music technology is the study or the use of any device, mechanism, machine or tool by a musician or composer to make or perform music; to compose, notate, playback or record songs or pieces; or to analyze or edit music.
History
The earliest known applications of technology to music was prehistoric peoples' use of a tool to hand-drill holes in bones to make simple flutes.
Ancient Egyptians developed stringed instruments, such as harps, lyres and lutes, which required making thin strings and some type of peg system for adjusting the pitch of the strings. Ancient Egyptians also used wind instruments such as double clarinets and percussion instruments such as cymbals.
In ancient Greece, instruments included the double-reed aulos and the lyre.
Numerous instruments are referred to in the Bible, including the cornu, pipe, lyre, harp, and bagpipe. During Biblical times, the cornu, flute, horn, pipe organ, pipe, and trumpet were also used.
During the Middle Ages, music notation was used to create a written record of the notes of plainchant melodies.
During the Renaissance music era (c. 1400–1600), the printing press was invented, allowing for sheet music to be mass-produced (previously having been hand-copied). This helped to spread musical styles more quickly and across a larger area.
During the Baroque era (c. 1600–1750), technologies for keyboard instruments developed, which led to improvements in the designs of pipe organs and the harpsichord, and the development of a new keyboard instrument in approximately 1700, the piano.
In the Classical era, Beethoven added new instruments to the orchestra such as the piccolo, contrabassoon, trombones, and untuned percussion in his Ninth Symphony.
During the Romantic music era (c. 1810–1900), one of the key ways that new compositions became known to the public was by the sales of sheet music, which amateur music lovers would perform at home on their piano or other instruments. In the 19th century, new instruments such as saxophones, euphoniums, Wagner tubas, and cornets were added to the orchestra.
Around the turn of the 20th century, with the invention and popularization of the gramophone record (commercialized in 1892), and radio broadcasting (starting on a commercial basis ca. 1919–1920), there was a vast increase in music listening, and it was easier to distribute music to a wider public.
The development of sound recording had a major influence on the development of popular music genres because it enabled recordings of songs and bands to be widely distributed. The invention of sound recording also gave rise to a new subgenre of classical music: the Musique concrete style of electronic composition.
The invention of multitrack recording enabled pop bands to overdub many layers of instrument tracks and vocals, creating new sounds that would not be possible in a live performance.
In the early 20th century, electric technologies such as electromagnetic pickups, amplifiers and loudspeakers were used to develop new electric instruments such as the electric piano (1929), electric guitar (1931), electro-mechanical organ (1934) and electric bass (1935). The 20th-century orchestra gained new instruments and new sounds. Some orchestra pieces used the electric guitar, electric bass or the Theremin.
The invention of the miniature transistor in 1947 enabled the creation of a new generation of synthesizers, which were used first in pop music in the 1960s. Unlike prior keyboard instrument technologies, synthesizer keyboards do not have strings, pipes, or metal tines. A synthesizer keyboard creates musical sounds using electronic circuitry, or, later, computer chips and software. Synthesizers became popular in the mass market in the early 1980s.
With the development of powerful microchips, a number of new electronic or digital music technologies were introduced in the 1980s and subsequent decades, including drum machines and music sequencers. Electronic and digital music technologies are any device, such as a computer, an electronic effects unit or software, that is used by a musician or composer to help make or perform music. The term usually refers to the use of electronic devices, computer hardware and computer software that is used in the performance, playback, composition, sound recording and reproduction, mixing, analysis and editing of music.
Mechanical technologies
Prehistoric eras
Findings from paleolithic archaeology sites suggest that prehistoric people used carving and piercing tools to create instruments. Archeologists have found Paleolithic flutes carved from bones in which lateral holes have been pierced. The disputed Divje Babe flute, a perforated cave bear femur, is at least 40,000 years old. Instruments such as the seven-holed flute and various types of stringed instruments, such as the Ravanahatha, have been recovered from the Indus Valley civilization archaeological sites. India has one of the oldest musical traditions in the world—references to Indian classical music (marga) are found in the Vedas, ancient scriptures of the Hindu tradition. The earliest and largest collection of prehistoric musical instruments was found in China and dates back to between 7000 and 6600 BC.
Ancient Egypt
In prehistoric Egypt, music and chanting were commonly used in magic and rituals, and small shells were used as whistles. Evidence of Egyptian musical instruments dates to the Predynastic period, when funerary chants played an important role in Egyptian religion and were accompanied by clappers and possibly the flute. The most reliable evidence of instrument technologies dates from the Old Kingdom, when technologies for constructing harps, flutes and double clarinets were developed. Percussion instruments, lyres and lutes were used by the Middle Kingdom. Metal cymbals were used by ancient Egyptians. In the early 21st century, interest in the music of the pharaonic period began to grow, inspired by the research of such foreign-born musicologists as Hans Hickmann. By the early 21st century, Egyptian musicians and musicologists led by the musicology professor Khairy El-Malt at Helwan University in Cairo had begun to reconstruct musical instruments of ancient Egypt, a project that is ongoing.
Indus Valley
The Indus Valley civilization has sculptures that show old musical instruments, like the seven-holed flute. Various types of stringed instruments and drums have been recovered from Harappa and Mohenjo Daro by excavations carried out by Sir Mortimer Wheeler.
References in the Bible
According to the Scriptures, Jubal was the father of harpists and organists (Gen. 4:20–21). The harp was among the chief instruments and the favorite of David, and it is referred to more than fifty times in the Bible. It was used at both joyful and mournful ceremonies, and its use was "raised to its highest perfection under David" (1 Sam. 16:23). Lockyer adds that "It was the sweet music of the harp that often dispossessed Saul of his melancholy (1 Sam. 16:14–23; 18:10–11). When the Jews were captive in Babylon they hung their harps up and refused to use them while in exile, earlier being part of the instruments used in the Temple (1 Kgs. 10:12). Another stringed instrument of the harp class, and one also used by the ancient Greeks, was the lyre. A similar instrument was the lute, which had a large pear-shaped body, long neck, and fretted fingerboard with head screws for tuning. Coins displaying musical instruments, the Bar Kochba Revolt coinage, were issued by the Jews during the Second Jewish Revolt against the Roman Empire of 132–135 AD. In addition to those, there was the psaltery, another stringed instrument that is referred to almost thirty times in Scripture. According to Josephus, it had twelve strings and was played with a quill, not with the hand. Another writer suggested that it was like a guitar, but with a flat triangular form and strung from side to side.
Among the wind instruments used in the biblical period were the cornet, flute, horn, organ, pipe, and trumpet. There were also silver trumpets and the double oboe. Werner concludes that from the measurements taken of the trumpets on the Arch of Titus in Rome and from coins, that "the trumpets were very high pitched with thin body and shrill sound." He adds that in War of the Sons of Light Against the Sons of Darkness, a manual for military organization and strategy discovered among the Dead Sea Scrolls, these trumpets "appear clearly capable of regulating their pitch pretty accurately, as they are supposed to blow rather complicated signals in unison." Whitcomb writes that the pair of silver trumpets were fashioned according to Mosaic law and were probably among the trophies that the Emperor Titus brought to Rome when he conquered Jerusalem. She adds that on the Arch raised to the victorious Titus, "there is a sculptured relief of these trumpets, showing their ancient form. (see photo)
The flute was commonly used for festal and mourning occasions, according to Whitcomb. "Even the poorest Hebrew was obliged to employ two flute players to perform at his wife's funeral." The shofar (the horn of a ram) is still used for special liturgical purposes such as the Jewish New Year services in orthodox communities. As such, it is not considered a musical instrument but an instrument of theological symbolism that has been intentionally kept to its primitive character. In ancient times it was used for warning of danger, to announce the new moon or beginning of Sabbath, or to announce the death of a notable. "In its strictly ritual usage it carried the cries of the multitude to God," writes Werner.
Among the percussion instruments were bells, cymbals, sistrum, tabret, hand drums, and tambourines. The tabret, or timbrel, was a small hand drum used for festive occasions and was considered a woman's instrument. In modern times it was often used by the Salvation Army. According to the Bible, when the children of Israel came out of Egypt and crossed the Red Sea, "Miriam took a timbrel in her hands; and all the women went out after her with timbrels and with dance."
Ancient Greece
In ancient Greece, instruments in all music can be divided into three categories, based on how sound is produced: string, wind, and percussion. The following were among the instruments used in the music of ancient Greece:
the lyre: a strummed and occasionally plucked string instrument, essentially a hand-held zither built on a tortoise-shell frame, generally with seven or more strings tuned to the notes of one of the modes. The lyre was used to accompany others or even oneself for recitation and song.
the kithara, also a strummed string instrument, more complicated than the lyre. It had a box-type frame with strings stretched from the cross-bar at the top to the sounding box at the bottom; it was held upright and played with a plectrum. The strings were tunable by adjusting wooden wedges along the cross-bar.
the aulos, usually double, consisting of two double-reed (like an oboe) pipes, not joined but generally played with a mouth-band to hold both pipes steadily between the player's lips. Modern reconstructions indicate that they produced a low, clarinet-like sound. There is some confusion about the exact nature of the instrument; alternate descriptions indicate single reeds instead of double reeds.
the Pan pipes, also known as panflute and syrinx (Greek συριγξ), (so-called for the nymph who was changed into a reed in order to hide from Pan) is an ancient musical instrument based on the principle of the stopped pipe, consisting of a series of such pipes of gradually increasing length, tuned (by cutting) to a desired scale. Sound is produced by blowing across the top of the open pipe (like blowing across a bottle top).
the hydraulis, a keyboard instrument, the forerunner of the modern organ. As the name indicates, the instrument used water to supply a constant flow of pressure to the pipes. Two detailed descriptions have survived: that of Vitruvius and Heron of Alexandria. These descriptions deal primarily with the keyboard mechanism and with the device by which the instrument was supplied with air. A well-preserved model in pottery was found at Carthage in 1885. Essentially, the air to the pipes that produce the sound comes from a wind chest connected by a pipe to a dome; air is pumped in to compress water, and the water rises in the dome, compressing the air, and causing a steady supply of air to the pipes.
In the Aeneid, Virgil makes numerous references to the trumpet. The lyre, kithara, aulos, hydraulis (water organ) and trumpet all found their way into the music of ancient Rome.
Roman Empire
The Romans may have borrowed the Greek method of enchiriadic notation to record their music if they used any notation at all. Four letters (in English notation 'A', 'G', 'F' and 'C') indicated a series of four succeeding tones. Rhythm signs, written above the letters, indicated the duration of each note. Roman art depicts various woodwinds, "brass", percussion and stringed instruments. Roman-style instruments are found in parts of the Empire where they did not originate and indicate that music was among the aspects of Roman culture that spread throughout the provinces.
Roman instruments include:
The Roman tuba was a long, straight bronze trumpet with a detachable, conical mouthpiece. Extant examples are about 1.3 metres long, and have a cylindrical bore from the mouthpiece to the point where the bell flares abruptly, similar to the modern straight trumpet seen in presentations of 'period music'. Since there were no valves, the tuba was capable only of a single overtone series. In the military, it was used for "bugle calls". The tuba is also depicted in art such as mosaics accompanying games (ludi) and spectacle events.
The cornu (Latin "horn") was a long tubular metal wind instrument that curved around the musician's body, shaped rather like an uppercase G. It had a conical bore (again like a French horn) and a conical mouthpiece. It may be hard to distinguish from the buccina. The cornu was used for military signals and on parade. The cornicen was a military signal officer who translated orders into calls. Like the tuba, the cornu also appears as accompaniment for public events and spectacle entertainments.
The tibia (Greek aulos – αὐλός), usually double, had two double-reed (as in a modern oboe) pipes, not joined but generally played with a mouth-band capistrum to hold both pipes steadily between the player's lips.
The askaules — a bagpipe.
Versions of the modern flute and panpipes.
The lyre, borrowed from the Greeks, was not a harp, but instead had a sounding body of wood or a tortoise shell covered with skin, and arms of animal horn or wood, with strings stretched from a cross bar to the sounding body.
The cithara was the premier musical instrument of ancient Rome and was played both in popular and elevated forms of music. Larger and heavier than a lyre, the cithara was a loud, sweet and piercing instrument with precision tuning ability.
The lute (pandura or monochord) was known by several names among the Greeks and Romans. In construction, the lute differs from the lyre in having fewer strings stretched over a solid neck or fret-board, on which the strings can be stopped to produce graduated notes. Each lute string is thereby capable of producing a greater range of notes than a lyre string. Although long-necked lutes are depicted in art from Mesopotamia as early as 2340–2198 BC, and also occur in Egyptian iconography, the lute in the Greco-Roman world was far less common than the lyre and cithara. The lute of the medieval West is thought to owe more to the Arab oud, from which its name derives (al ʿūd).
The hydraulic pipe organ (hydraulis), which worked by water pressure, was "one of the most significant technical and musical achievements of antiquity". Essentially, the air to the pipes that produce the sound comes from a mechanism of a wind-chest connected by a pipe to a dome; air is pumped in to compress water, and the water rises in the dome, compressing the air and causing a steady supply to reach the pipes (also see Pipe organ#History). The hydraulis accompanied gladiator contests and events in the arena, as well as stage performances.
Variations of a hinged wooden or metal device, called a scabellum used to beat time. Also, there were various rattles, bells and tambourines.
Drum and percussion instruments like timpani and castanets, the Egyptian sistrum, and brazen pans, served various musical and other purposes in ancient Rome, including backgrounds for rhythmic dance, celebratory rites like those of the Bacchantes and military uses.
The sistrum was a rattle consisting of rings strung across the cross-bars of a metal frame, which was often used for ritual purposes.
Cymbala (Lat. plural of cymbalum, from the Greek kymbalon) were small cymbals: metal discs with concave centres and turned rims, used in pairs which were clashed together.
Islamic world
A number of musical instruments later used in medieval European music were influenced by Arabic musical instruments, including the rebec (an ancestor of the violin) from the rebab and the naker from naqareh. Many European instruments have roots in earlier Eastern instruments that were adopted from the Islamic world. The Arabic rabāb, also known as the spiked fiddle, is the earliest known bowed string instrument and the ancestor of all European bowed instruments, including the rebec, the Byzantine lyra, and the violin.
The plucked and bowed versions of the rebab existed alongside each other. The bowed instruments became the rebec or rabel and the plucked instruments became the gittern. Curt Sachs linked this instrument with the mandola, the kopuz and the gambus, and named the bowed version rabâb.
The Arabic oud in Islamic music was the direct ancestor of the European lute. The oud is also cited as a precursor to the modern guitar. The guitar has roots in the four-string oud, brought to Iberia by the Moors in the 8th century. A direct ancestor of the modern guitar is the (Moorish guitar), which was in use in Spain by 1200. By the 14th century, it was simply referred to as a guitar.
The origin of automatic musical instruments dates back to the 9th century when the Persian Banū Mūsā brothers invented a hydropowered organ using exchangeable cylinders with pins, and also an automatic flute playing machine using steam power. These were the earliest automated mechanical musical instruments. The Banu Musa brothers' automatic flute player was the first programmable musical device, the first music sequencer, and the first example of repetitive music technology, powered by hydraulics.
In 1206, the Arab engineer Al-Jazari invented a programmable humanoid automata band. According to Charles B. Fowler, the automata were a "robot band" which performed "more than fifty facial and body actions during each musical selection." It was also the first programmable drum machine. Among the four automaton musicians, two were drummers. It was a drum machine where pegs (cams) bumped into little levers that operated the percussion. The drummers could be made to play different rhythms and different drum patterns if the pegs were moved around.
Middle Ages
During the medieval music era (476 to 1400) the plainchant tunes used for religious songs were primarily monophonic (a single line, unaccompanied melody). In the early centuries of the medieval era, these chants were taught and spread by oral tradition ("by ear"). The earliest Medieval music did not have any kind of notational system for writing down melodies. As Rome tried to standardize the various chants across vast distances of its empire, a form of music notation was needed to write down the melodies. Various signs written above the chant texts, called neumes were introduced. By the ninth century, it was firmly established as the primary method of musical notation. The next development in musical notation was heighted neumes, in which neumes were carefully placed at different heights in relation to each other. This allowed the neumes to give a rough indication of the size of a given interval as well as the direction.
This quickly led to one or two lines, each representing a particular note, being placed on the music with all of the neumes relating back to them. The line or lines acted as a reference point to help the singer gauge which notes were higher or lower. At first, these lines had no particular meaning and instead had a letter placed at the beginning indicating which note was represented. However, the lines indicating middle C and the F a fifth below slowly became most common. The completion of the four-line staff is usually credited to Guido d' Arezzo (c. 1000–1050), one of the most important musical theorists of the Middle Ages. The neumatic notational system, even in its fully developed state, did not clearly define any kind of rhythm for the singing of notes or playing of melodies. The development of music notation made it faster and easier to teach melodies to new people, and facilitated the spread of music over long geographic distances.
Instruments used to perform medieval music include earlier, less mechanically sophisticated versions of a number of instruments that continue to be used in the 2010s. Medieval instruments include the flute, which was made of wood and could be made as a side-blown or end-blown instrument (it lacked the complex metal keys and airtight pads of 2010s-era metal flutes); the wooden recorder and the related instrument called the gemshorn; and the pan flute (a group of air columns attached together). Medieval music used many plucked string instruments like the lute, mandore, gittern and psaltery. The dulcimers, similar in structure to the psaltery and zither, were originally plucked, but became struck by hammers in the 14th century after the arrival of new technology that made metal strings possible.
Bowed strings were used as well. The bowed lyra of the Byzantine Empire was the first recorded European bowed string instrument. The Persian geographer Ibn Khurradadhbih of the 9th century (d. 911) cited the Byzantine lyra as a bowed instrument equivalent to the Arab rabāb and typical instrument of the Byzantines along with the urghun (organ), shilyani (probably a type of harp or lyre) and the salandj (probably a bagpipe). The hurdy-gurdy was a mechanical violin using a rosined wooden wheel attached to a crank to "bow" its strings. Instruments without sound boxes like the jaw harp were also popular in the time. Early versions of the organ, fiddle (or vielle), and trombone (called the sackbut) existed in the medieval era.
Renaissance
The Renaissance music era (c. 1400 to 1600) saw the development of many new technologies that affected the performance and distribution of songs and musical pieces. Around 1450, the printing press was invented, which made printed sheet music much less expensive and easier to mass-produce (prior to the invention of the printing press, all notated music was laboriously hand-copied). The increased availability of printed sheet music helped to spread musical styles more quickly and across a larger geographic area.
Many instruments originated during the Renaissance; others were variations of, or improvements upon, instruments that had existed previously in the medieval era. Brass instruments in the Renaissance were traditionally played by professionals. Some of the more common brass instruments that were played included:
Slide trumpet: Similar to the trombone of today except that instead of a section of the body sliding, only a small part of the body near the mouthpiece and the mouthpiece itself is stationary.
Cornett: Made of wood and was played like the recorder, but blown like a trumpet.
Trumpet: Early trumpets from the Renaissance era had no valves, and were limited to the tones present in the overtone series. They were also made in different sizes.
Sackbut: A different name for the trombone, which replaced the slide trumpet by the middle of the 15th century
Stringed instruments included:
Viol: This instrument, developed in the 15th century, commonly has six strings. It was usually played with a bow.
Lyre: Its construction is similar to a small harp, although instead of being plucked, it is strummed with a plectrum. Its strings varied in quantity from four, seven, and ten, depending on the era. It was played with the right hand, while the left hand silenced the notes that were not desired. Newer lyres were modified to be played with a bow.
Hurdy-gurdy: (Also known as the wheel fiddle), in which the strings are sounded by a wheel which the strings pass over. Its functionality can be compared to that of a mechanical violin, in that its bow (wheel) is turned by a crank. Its distinctive sound is mainly because of its "drone strings" which provide a constant pitch similar in their sound to that of bagpipes.
Gittern and mandore: these instruments were used throughout Europe. Forerunners of modern instruments including the mandolin and acoustic guitar.
Percussion instruments included:
Tambourine: The tambourine is a frame drum equipped with jingles that produce a sound when the drum is struck.
Jew's harp: An instrument that produces sound using shapes of the mouth and attempting to pronounce different vowels with one's mouth.
Woodwind instruments included:
Shawm: A typical shawm is keyless and is about a foot long with seven finger holes and a thumb hole. The pipes were also most commonly made of wood and many of them had carvings and decorations on them. It was the most popular double reed instrument of the Renaissance period; it was commonly used in the streets with drums and trumpets because of its brilliant, piercing, and often deafening sound. To play the shawm a person puts the entire reed in their mouth, puffs out their cheeks, and blows into the pipe whilst breathing through their nose.
Reed pipe: Made from a single short length of cane with a mouthpiece, four or five finger holes, and reed fashioned from it. The reed is made by cutting out a small tongue but leaving the base attached. It is the predecessor of the saxophone and the clarinet.
Hornpipe: Same as reed pipe but with a bell at the end.
Bagpipe/Bladderpipe: It used a bag made out of sheep or goat skin that would provide air pressure for a pipe. When the player takes a breath, the player only needs to squeeze the bag tucked underneath their arm to continue the tone. The mouth pipe has a simple round piece of leather hinged on to the bag end of the pipe and acts like a non-return valve. The reed is located inside the long metal mouthpiece, known as a bocal.
Panpipe: Designed to have sixteen wooden tubes with a stopper at one end and open on the other. Each tube is a different size (thereby producing a different tone), giving it a range of an octave and a half. The player can then place their lips against the desired tube and blow across it.
Transverse flute: The transverse flute is similar to the modern flute with a mouth hole near the stoppered end and finger holes along the body. The player blows in the side and holds the flute to the right side.
Recorder: It uses a whistle mouthpiece, which is a beak-shaped mouthpiece, as its main source of sound production. It is usually made with seven finger holes and a thumb hole.
Baroque
During the Baroque era of music (ca. 1600–1750), technologies for keyboard instruments developed, which led to improvements in the designs of pipe organs and harpsichords, and to the development of the first pianos. During the Baroque period, organ builders developed new types of pipes and reeds that created new tonal colors. Organ builders fashioned new stops that imitated various instruments, such as the viola da gamba. The Baroque period is often thought of as organ building's "golden age," as virtually every important refinement to the instrument was brought to a peak. Builders such as Arp Schnitger, Jasper Johannsen, Zacharias Hildebrandt and Gottfried Silbermann constructed instruments that displayed both exquisite craftsmanship and beautiful sound. These organs featured well-balanced mechanical key actions, giving the organist precise control over the pipe speech. Schnitger's organs featured particularly distinctive reed timbres and large Pedal and Rückpositiv divisions.
Harpsichord builders in the Southern Netherlands built instruments with two keyboards that could be used for transposition. These Flemish instruments served as the model for Baroque-era harpsichord construction in other nations. In France, the double keyboards were adapted to control different choirs of strings, making a more musically flexible instrument (e.g., the upper manual could be set to a quiet lute stop, while the lower manual could be set to a stop with multiple string choirs, for a louder sound). Instruments from the peak of the French tradition, by makers such as the Blanchet family and Pascal Taskin, are among the most widely admired of all harpsichords and are frequently used as models for the construction of modern instruments. In England, the Kirkman and Shudi firms produced sophisticated harpsichords of great power and sonority. German builders extended the sound repertoire of the instrument by adding sixteen-foot choirs, adding to the lower register and two-foot choirs, which added to the upper register.
The piano was invented during the Baroque era by the expert harpsichord maker Bartolomeo Cristofori (1655–1731) of Padua, Italy, who was employed by Ferdinando de' Medici, Grand Prince of Tuscany. Cristofori invented the piano at some point before 1700. While the clavichord allowed expressive control of volume, with harder or louder key presses creating louder sound (and vice versa) and fairly sustained notes, it was too quiet for large performances. The harpsichord produced a sufficiently loud sound, but offered little expressive control over each note. Pressing a harpsichord key harder or softer had no effect on the instrument's loudness. The piano offered the best of both, combining loudness with dynamic control. Cristofori's great success was solving, with no prior example, the fundamental mechanical problem of piano design: the hammer must strike the string, but not remain in contact with it (as a tangent remains in contact with a clavichord string) because this would damp the sound. Moreover, the hammer must return to its rest position without bouncing violently, and it must be possible to repeat the same note rapidly. Cristofori's piano action was a model for the many approaches to piano actions that followed. Cristofori's early instruments were much louder and had more sustain than the clavichord. Even though the piano was invented in 1700, the harpsichord and pipe organ continued to be widely used in orchestra and chamber music concerts until the end of the 1700s. It took time for the new piano to gain in popularity. By 1800, though, the piano generally was used in place of the harpsichord (although pipe organ continued to be used in church music such as Masses).
Classicism
From about 1790 onward, the Mozart-era piano underwent tremendous changes that led to the modern form of the instrument. This revolution was in response to a preference by composers and pianists for a more powerful, sustained piano sound, and made possible by the ongoing Industrial Revolution with resources such as high-quality steel piano wire for strings, and precision casting for the production of iron frames. Over time, the tonal range of the piano was also increased from the five octaves of Mozart's day to the 7-plus range found on modern pianos.
Early technological progress owed much to the firm of Broadwood. John Broadwood joined with another Scot, Robert Stodart, and a Dutchman, Americus Backers, to design a piano in the harpsichord case—the origin of the "grand". They achieved this in about 1777. They quickly gained a reputation for the splendour and powerful tone of their instruments, with Broadwood constructing ones that were progressively larger, louder, and more robustly constructed.
They sent pianos to both Joseph Haydn and Ludwig van Beethoven, and were the first firm to build pianos with a range of more than five octaves: five octaves and a fifth (interval) during the 1790s, six octaves by 1810 (Beethoven used the extra notes in his later works), and seven octaves by 1820. The Viennese makers similarly followed these trends; however the two schools used different piano actions: Broadwoods were more robust, Viennese instruments were more sensitive.
Beethoven's instrumentation for orchestra added piccolo, contrabassoon, and trombones to the triumphal finale of his Symphony No. 5. A piccolo and a pair of trombones help deliver storm and sunshine in the Sixth. Beethoven's use of piccolo, contrabassoon, trombones, and untuned percussion in his Ninth Symphony expanded the sound of the orchestra.
Romanticism
During the Romantic music era (c. 1810 to 1900), one of the key ways that new compositions became known to the public was by the sales of sheet music, which amateur music lovers would perform at home on their piano or in chamber music groups, such as string quartets. Saxophones began to appear in some 19th-century orchestra scores. While appearing only as featured solo instruments in some works, for example Maurice Ravel's orchestration of Modest Mussorgsky's Pictures at an Exhibition and Sergei Rachmaninoff's Symphonic Dances, the saxophone is included in other works, such as Ravel's Boléro, Sergei Prokofiev's Romeo and Juliet Suites 1 and 2. The euphonium is featured in a few late Romantic and 20th-century works, usually playing parts marked "tenor tuba", including Gustav Holst's The Planets, and Richard Strauss's Ein Heldenleben. The Wagner tuba, a modified member of the horn family, appears in Richard Wagner's cycle Der Ring des Nibelungen and several other works by Strauss, Béla Bartók, and others; it has a prominent role in Anton Bruckner's Symphony No. 7 in E Major. Cornets appear in Pyotr Ilyich Tchaikovsky's ballet Swan Lake, Claude Debussy's La Mer, and several orchestral works by Hector Berlioz.
The piano continued to undergo technological developments in the Romantic era, up until the 1860s. By the 1820s, the center of piano building innovation had shifted to Paris, where the Pleyel firm manufactured pianos used by Frédéric Chopin and the Érard firm manufactured those used by Franz Liszt. In 1821, Sébastien Érard invented the double escapement action, which incorporated a repetition lever (also called the balancier) that permitted repeating a note even if the key had not yet risen to its maximum vertical position. This facilitated rapid playing of repeated notes, a musical device exploited by Liszt. When the invention became public, as revised by Henri Herz, the double escapement action gradually became standard in grand pianos and is still incorporated into all grand pianos currently produced. Other improvements of the mechanism included the use of felt hammer coverings instead of layered leather or cotton. Felt, which was first introduced by Jean-Henri Pape in 1826, was a more consistent material, permitting wider dynamic ranges as hammer weights and string tension increased. The sostenuto pedal, invented in 1844 by Jean-Louis Boisselot and copied by the Steinway firm in 1874, allowed a wider range of effects.
One innovation that helped create the sound of the modern piano was the use of a strong iron frame. Also called the "plate", the iron frame sits atop the soundboard, and serves as the primary bulwark against the force of string tension that can exceed 20 tons in a modern grand. The single piece cast iron frame was patented in 1825 in Boston by Alpheus Babcock, combining the metal hitch pin plate (1821, claimed by Broadwood on behalf of Samuel Hervé) and resisting bars (Thom and Allen, 1820, but also claimed by Broadwood and Érard). The increased structural integrity of the iron frame allowed the use of thicker, tenser, and more numerous strings. In 1834, the Webster & Horsfal firm of Birmingham brought out a form of piano wire made from cast steel; according to Dolge it was "so superior to the iron wire that the English firm soon had a monopoly."
Other important advances included changes to the way the piano is strung, such as the use of a "choir" of three strings rather than two for all but the lowest notes, and the implementation of an over-strung scale, in which the strings are placed in two separate planes, each with its own bridge height. The mechanical action structure of the upright piano was invented in London, England in 1826 by Robert Wornum, and upright models became the most popular model, also amplifying the sound.
20th- and 21st-century music
With 20th-century music, there was a vast increase in music listening, as the radio gained popularity and phonographs were used to replay and distribute music. The invention of sound recording and the ability to edit music gave rise to new subgenre of classical music, including the acousmatic and Musique concrète schools of electronic composition. Sound recording was also a major influence on the development of popular music genres, because it enabled recordings of songs and bands to be widely distributed. The introduction of the multitrack recording system had a major influence on rock music, because it could do much more than record a band's performance. Using a multitrack system, a band and their music producer could overdub many layers of instrument tracks and vocals, creating new sounds that would not be possible in a live performance.
The 20th-century orchestra was far more flexible than its predecessors. In Beethoven's and Felix Mendelssohn's time, the orchestra was composed of a fairly standard core of instruments which was very rarely modified. As time progressed, and as the Romantic period saw changes in accepted modification with composers such as Berlioz and Mahler, the 20th century saw that instrumentation could practically be hand-picked by the composer. Saxophones were used in some 20th-century orchestra scores such as Vaughan Williams' Symphonies No. 6 and 9 and William Walton's Belshazzar's Feast, and many other works as a member of the orchestral ensemble. In the 2000s, the modern orchestra became standardized with the modern instrumentation that includes a string section, woodwinds, brass instruments, percussion, piano, celeste, and even, for some 20th century or 21st-century works, electric instruments such as electric guitar, electric bass and/or electronic instruments such as the Theremin or synthesizer.
Electric and electro-mechanical
Electric music technology refers to musical instruments and recording devices that use electrical circuits, which are often combined with mechanical technologies. Examples of electric musical instruments include the electro-mechanical electric piano (invented in 1929), the electric guitar (invented in 1931), the electro-mechanical Hammond organ (developed in 1934) and the electric bass (invented in 1935). None of these electric instruments produce a sound that is audible by the performer or audience in a performance setting unless they are connected to instrument amplifiers and loudspeaker cabinets, which made them sound loud enough for performers and the audience to hear. Amplifiers and loudspeakers are separate from the instrument in the case of the electric guitar (which uses a guitar amplifier), electric bass (which uses a bass amplifier) and some electric organs (which use a Leslie speaker or similar cabinet) and electric pianos. Some electric organs and electric pianos include the amplifier and speaker cabinet within the main housing for the instrument.
Electric piano
An electric piano is an electric musical instrument which produces sounds when a performer presses the keys of the piano-style musical keyboard. Pressing keys causes mechanical hammers to strike metal strings or tines, leading to vibrations which are converted into electrical signals by magnetic pickups, which are then connected to an instrument amplifier and loudspeaker to make a sound loud enough for the performer and audience to hear. Unlike a synthesizer, the electric piano is not an electronic instrument. Instead, it is an electromechanical instrument. Some early electric pianos used lengths of wire to produce the tone, like a traditional piano. Smaller electric pianos used short slivers of steel, metal tines or short wires to produce the tone. The earliest electric pianos were invented in the late 1920s.
Electric guitar
An electric guitar is a guitar that uses a pickup to convert the vibration of its strings into electrical impulses. The most common guitar pickup uses the principle of direct electromagnetic induction. The signal generated by an electric guitar is too weak to drive a loudspeaker, so it is amplified before being sent to a loudspeaker. The output of an electric guitar is an electric signal, and the signal can easily be altered by electronic circuits to add "color" to the sound. Often the signal is modified using electronic effects such as reverb and distortion. Invented in 1931, the electric guitar became a necessity as jazz guitarists sought to amplify their sound in the big band format.
Hammond organ
The Hammond organ is an electric organ, invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Various models have been produced, most of which use sliding drawbars to create a variety of sounds. Until 1975, Hammond organs generated sound by creating an electric current from rotating a metal tonewheel near an electromagnetic pickup. Around two million Hammond organs have been manufactured, and it has been described as one of the most successful organs. The organ is commonly used with, and associated with, the Leslie speaker. The organ was originally marketed and sold by the Hammond Organ Company to churches as a lower-cost alternative to the wind-driven pipe organ, or instead of a piano. It quickly became popular with professional jazz bandleaders, who found that the room-filling sound of a Hammond organ could form small bands such as organ trios which were less costly than paying an entire big band.
Electric bass
The electric bass (or bass guitar) was invented in the 1930s, but it did not become commercially successful or widely used until the 1950s. It is a stringed instrument played primarily with the fingers or thumb, by plucking, slapping, popping, strumming, tapping, thumping, or picking with a plectrum, often known as a pick. The bass guitar is similar in appearance and construction to an electric guitar, but with a longer neck and scale length, and four to six strings or courses. The electric bass usually uses metal strings and an electromagnetic pickup which senses the vibrations in the strings. Like the electric guitar, the bass guitar is plugged into an amplifier and speaker for live performances.
Electronic or digital
Electronic or digital music technology is any device, such as a computer, an electronic effects unit or software, that is used by a musician or composer to help make or perform music. The term usually refers to the use of electronic devices, computer hardware and computer software that is used in the performance, composition, sound recording and reproduction, mixing, analysis and editing of music. Electronic or digital music technology is connected to both artistic and technological creativity. Musicians and music technology experts are constantly striving to devise new forms of expression through music, and they are physically creating new devices and software to enable them to do so. Although in the 2010s, the term is most commonly used in reference to modern electronic devices and computer software such as digital audio workstations and Pro Tools digital sound recording software, electronic and digital musical technologies have precursors in the electric music technologies of the early 20th century, such as the electromechanical Hammond organ, which was invented in 1929. In the 2010s, the ontological range of music technology has greatly increased, and it may now be electronic, digital, software-based or indeed even purely conceptual.
A synthesizer is an electronic musical instrument that generates electric signals that are converted to sound through instrument amplifiers and loudspeakers or headphones. Synthesizers may either imitate existing sounds (instruments, vocal, natural sounds, etc.), or generate new electronic timbres or sounds that did not exist before. They are often played with an electronic musical keyboard, but they can be controlled via a variety of other input devices, including music sequencers, instrument controllers, fingerboards, guitar synthesizers, wind controllers, and electronic drums. Synthesizers without built-in controllers are often called sound modules, and are controlled using a controller device.
References
Sources
Further reading
External links
Sound recording
Audio electronics
Music history
Musical instruments | Music technology | [
"Engineering"
] | 9,298 | [
"Audio electronics",
"Audio engineering"
] |
49,182,508 | https://en.wikipedia.org/wiki/Extended%20female%20sexuality | Extended female sexuality is where the female of a species mates despite being infertile. In most species, the female only engages in copulation when she is fertile. However, extended sexuality has been documented in Old World primates, pair bonded birds and some insects (such as carrion beetles). Extended sexuality is most prominent in human females who exhibit no change in copulation rate across the ovarian cycle.
Although this behaviour incurs costs to females, such as energy and time, many researchers have proposed reasons for its existence. These hypotheses include the male assistance hypothesis, which proposes that females gain non-genetic benefits (such as food and shelter) in exchange for sexual access. A sub-hypothesis of this is Hrdy's, proposing extended female sexuality as an adaptive process aiming to creating paternity confusion in males. Alternative hypotheses, classified as 'male-driven', claim that extended female sexuality occurs due to male adaptations, resulting from an inability to detect fertility status in females or to dampen immune responses against sperm. Finally, Spuhler's hypothesis suggests that the behaviour may have arisen as an incidental effect of larger adrenal glands in humans.
Occurrence
In non-humans
Although not found in all organisms, researchers have identified sexual intercourse patterns in certain animals that reflect extended female sexuality, such as in some old world primates, birds and insects. Extensive research has focused on analysing the musk shrew's rate of sexual behaviour. The only period that is associated with a drop in female receptivity to copulation is during mid to late pregnancy; yet, even at this time, occasional mating is reported. Therefore, researchers have concluded that this animal has similar sexual receptivity across infertile and fertile phases. Within primates, research has consistently found evidence of extended female sexuality in the rhesus monkey and chimpanzees. Both of these primates mate at all stages of the ovarian cycle, with only slight increases in sexual receptivity during fertile stages, and decreases during menstruation.
In humans
Human females are considered to exhibit the greatest degree of extended female sexuality, with receptivity to sexual intercourse remaining constant across fertile and infertile phases of the reproductive cycle, including during pregnancy, lactation, and in adolescence. In a study of 20,000 women from 13 countries, frequency of copulation was reportedly the same across all stages of the ovarian cycle. The only notable drop in sexual behaviour occurred during menstruation. Therefore, women largely showed the same level of sexual behaviour in the non-fertile phases of their ovarian cycles as in the fertile phases.
Researchers have investigated the effect of hormonal contraceptive use in women on the frequency of sexual intercourse. Many of these contraceptives mimic a pregnancy state in females by altering hormone levels. Therefore, women who use these contraceptives do not experience the fertile phases of their cycles. In a systematic review, it appeared that the frequency of sexual intercourse was unaffected by contraceptive use in the majority of women. Although artificially created, this adds to the literature documenting the existence of copulation in humans during non-fertile periods.
Impact of concealed ovulation
In order to encourage mating in non-conceptive periods and to encourage males to maintain their proximity, males must possess imperfect knowledge of the female's fertility status. This is achieved through concealed ovulation in most animals that exhibit extended female sexuality. A review of studies revealed that, in humans, females only exhibit subtle changes during estrus, making it difficult for males to assess fertility with precision. In the !Kung tribe, for instance, females lack any overt signals of fertility and are continuously receptive to sexual intercourse, encouraging males to remain and provide resources.
Explanations
Male assistance hypothesis
Mating outside the fertile window of their ovarian cycle may incur considerable costs for females, such as in time and energy usage. To counteract these costs, the male assistance hypothesis argues that females exhibit extended sexuality to obtain resources from males. These resources vary between species, but can include food, social alliance, and protection of the female and her offspring. For example, in the Trobriand tribe, men give women gifts in exchange for sexual access. From this hypothesis, three predictions can be made.
Male provision of non-genetic resources
Firstly, in species that demonstrate extended female sexuality, there should be evidence that the males provide non-genetic resources to females. This prediction is supported in a variety of animals, with reviews revealing that male assistance (such as food or protection), is provided to certain mammals and communally breeding birds in exchange for mating outside the conceptive period. For example, female blackbirds that solicit mating outside the fertile period have increased mate guarding from their pair-bonded partner. This increases protection against other sexually coercive males and ensures the provision of other material benefits. In a review investigating primates that exhibit extended female sexuality, it was noted that females engaging in extended sexuality benefited from increased offspring protection and paternal care from males.
Enhanced reproductive success
Secondly, in order to outweigh the aforementioned costs, mating during infertile phases should increase females' reproductive success by increasing the number of offspring produced. Current research has only investigated this factor indirectly, and it has predominantly been investigated in insects. For example, when male insects deliver material benefits in exchange for sexual access, the reproductive success of the females increases with the number of matings. It is important to note that the mating behaviour assessed was not limited to extended female sexuality. Hence, it only provides indirect support for the second prediction.
Shifting mate preferences and behaviour across the ovarian cycle
The final prediction of the male-assistance hypothesis has been extensively investigated. It predicts that females will exhibit differing mate preferences during fertile and non-fertile periods. Specifically, when fertile, the females will be sensitive to indicators of high genetic quality to increase the genetic quality of her offspring. Conversely, outside of the fertile period, females will show a preference for males who can provide resources for her and her offspring. In most species, males of higher genetic quality offer fewer non-genetic resources (such as shelter and food) than those of lower quality, so females are likely to choose different males at each stage.
Evidence for this prediction has been found in many different species. In hens, those near peak fertility show a preference for socially dominant roosters with large combs. Larger combs have been reliably associated with health and offspring survival so reliably indicate the genetic quality of the rooster. In the non-fertile phases, hens mate more indiscriminately with less regard for the larger comb size. A similar pattern emerges in humans. A review of relevant studies on female preferences across the ovarian cycle reveals that women show a greater preference for masculine traits in fertile phases, especially for short term mating intention. This finding occurs across a variety of traits, such as masculine voices, body and facial features, scent, and behavioural displays. The level of masculinity acts as an indicator of genetic quality through its association with high testosterone. Similarly, women show a preference for higher levels of symmetry, which is thought to indicate underlying developmental stability. However, during infertile phases, women prefer males with lower masculinity and symmetry, as they tend to be more willing to offer material benefits.
In addition to impacting mating preferences, females have been found to exhibit differing mating behaviour at different cycle stages. An analysis of 121 studies with female birds showed that most mate outside their pair bond at a higher rate when fertile, especially when the primary partner possesses indicators of low quality genes. During infertile phases, birds showed reductions in this behaviour, suggesting that the function of extended female sexuality is not to increase the genetic quality of offspring. In humans, females show increased motivation for mating with other males at mid-cycle without an accompanying increase in copulation with their long-term partner, especially if the partner was less physically attractive.
Hrdy's hypothesis
Hrdy's hypothesis is an extension of the male assistance hypothesis, in that both hypotheses argue that women have evolved this adaptation to gain some tangible benefit from males. According to Hrdy's hypothesis, extended female sexuality is an adaptive process with an aim of creating paternity confusion in their male counterparts. Paternity confusion refers to the male being unsure as to whether offspring are genetically his own. If the female mates with different males (at all points of her ovarian cycle) whilst concealing fertility, then the males will inevitably have paternity confusion.
Paternity confusion is proposed to be an adaptive function for preventing infanticide. Thus, if the female can successfully create paternity confusion, males will be less likely to kill her offspring, as the lack of paternity certainty means that they run the risk of killing their own genetic offspring. Additionally, the males, in turn, are likely to protect the same female's offspring from infanticide that may be committed by other adults within the species. Once again, this is because they are uncertain about paternity, and aim to protect infants that are genetically their own.
Paternity confusion in primates
Researchers have analysed the behaviour of chimpanzees, with particular reference to copulation calling. Copulation calling is a type of vocalisation used to attract mates. The calls are vocalised either before, during, or after sexual intercourse. Copulation calling, in line with Hrdy's hypothesis, may then be one way to ensure that the female can mate with as many different males as possible, causing paternity confusion. Indeed, the authors found that the probability of copulatory calling in female chimpanzees was not modulated by the ovarian phase of the female caller, thereby aiding paternity confusion. This paternity confusion ultimately ensures that the woman has access to the resources of a number of different males. These resources can be utilised by her, as well as by her offspring.
Criticism of Hrdy's hypothesis emerges from evidence which suggests that male primates can discriminate between their own offspring and the offspring of others. In one study, researchers analysed the DNA of 75 juvenile baboons to conclude who fathered them. They found that males selectively cared for their own offspring, particularly when their offspring became involved in aggressive confrontations which posed the possibility of injuries or a threat to their social standing. Evidently, if males can discriminate between their own offspring and the offspring of others, then there is no purpose in the female attempting to create paternity confusion during the pregnancy stage. This would be counter-intuitive, as, once the offspring is born, the males will know whether the offspring is, or is not, their own. Future research will need to be conducted in this vein to investigate whether males in other species show the ability to discriminate between their own offspring and the offspring of others before coming to any decisive conclusions.
Concealed estrus as a function of paternity confusion in primates
Research is fairly consistent in the finding that species with concealed estrus mate at all stages of their ovarian cycle. For instance, mating activity in assamese macaques (Macaca assamensis) has been investigated. The researchers analysed the levels of progesterone in the monkeys, in order to establish the ovarian stage of the female, as progesterone peaks following the fertile window. They found that the females concealed estrus and were sexually receptive during the entire mating season. Concealed estrus and sexual receptivity (at all times of the ovarian cycle) aids paternity confusion. This is because the males are unsure of who mated with the female during her fertile period, and so do not know the identity of the father.
Hrdy's hypothesis has been criticised, however, on the basis that some female primates show both extended female sexuality and sexual swellings. In terms of Hrdy's hypothesis, these two concepts are incompatible. Sexual swellings appear only during the most fertile phase of the female's ovarian cycle, with the purpose of advertising fertility. In sharp contrast, according to Hrdy, extended sexuality is adapted to conceal fertility and ensure mating across all stages of the ovarian cycle, to aid paternity confusion.
Male-driven hypotheses
One of the alternative explanations is that extended female sexuality is 'male-driven'. This hypothesis is theoretically based on male uncertainty regarding the fertility status of females. Although some physiological changes occur during the fertile period that may act as reliable indicators (e.g. the concentration of oestrogen can change female scent), most species have not evolved signals advertising fertility (e.g. sexual swellings). Therefore, males will be unable to detect fertility with any precision. As a result, extended female sexuality is proposed as a male sexually selected trait. Males will pursue sexual access throughout the entirety of the ovarian cycle to increase their chances of impregnating the female. According to this hypothesis, females lack any benefit from this activity due to their inability to conceive, yet will be coerced by males to engage in sexual intercourse.
The training hypothesis
Another hypothesis claiming that extended female sexuality has evolved to benefit males' interests is the 'training hypothesis'. It has been shown that women's immune systems attack foreign antigens found in sperm. This may reduce the likelihood of conception and so reduce the reproductive success for the males. However, prior exposure to sperm antigens can dampen the immune response to increase the chances of successful conception and implantation. Therefore, males may have evolved to train and 'condition' women's immune systems by copulating with females during infertile periods, in order to reduce the likelihood of her immune system reacting against the sperm's antigens from lack of exposure. Indeed, research has identified findings consistent with this hypothesis. Couples who had used condoms before trying to conceive were more likely to suffer complications, such as pre-eclampsia, during pregnancy as a result of the woman's immune system having no prior exposure to the antigens in the sperm. In non-humans, an increased frequency of copulation in crickets has been shown to reduce the female's immune response to sperm.
This hypothesis has received much criticism . For example, as all mammals experience the same immune system responses to sperm antigens, this hypothesis predicts that all mammals should exhibit extended female sexuality. However, only few species of mammals exhibit sexual behaviour outside the conceptive period. On the other hand, eclampsia is virtually unique to humans and thus the Training Hypothesis may only be relevant to extended female sexuality in humans.
Spuhler's hypothesis
Spuhler's hypothesis is a stand-alone hypothesis of extended female sexuality. Spuhler suggests that extended female sexuality has evolved as a by-product of an adaptation in females that increases the levels of adrenal hormones. He proposed that secretion of higher levels of adrenal hormones were initially selected in women in order to increase endurance for walking or running. This hypothesis suggests that the larger adrenal glands may have contributed to the development of extended female sexuality as they are also the main source of 'libido hormones', which increase the female's sexual drive. Thus, extended sexuality is little to do with sexual behavior, or evolutionary advantage, but rather it is just a by-product of hormones. However, this hypothesis cannot account for extended female sexuality in invertebrates, which lack adrenal systems. Additionally Spuhler highlighted the existence of larger thyroid and adrenal glands in humans compared to other primates. However, no empirical evidence has established the link between hormones and endurance walking as an adaptation and extended female sexuality as a natural incidental effect. As there are costs to extended sexuality, it can be argued that selection would serve the dissociation of extended sexuality from the mechanism that affects endurance walking.
See also
Alternative mating strategy
Animal sexual behaviour
Human female sexuality
Human mating strategies
Strategic pluralism
Human sexual activity
Human sexuality
Major histocompatibility complex and sexual selection
Mating system
Ovulatory shift hypothesis
Reproduction
References
Further reading
Buss, D. M. (2015). The Handbook of Evolutionary Psychology, Foundation (Chapter 13). New York: John Wiley & Sons.
Campbell, L. (2009, June 17). Comparison of the sexuality of humans, common chimpanzees and bonobos.
Shackelford, T. K., & Hansen, R. D. (2015). The Evolution of Sexuality (Chapter 8). New York: Springer.
Simpson, J. A., & Campbell, L. (2013). The Oxford Handbook of Close Relationships (Chapter 17). Oxford: University Press.
Thornhill, R., & Gangestad, S. W. (2008). The Evolutionary Biology of Human Female Sexuality (Chapter 3). Oxford: University Press.
Animal sexuality
Evolutionary biology
Human sexuality | Extended female sexuality | [
"Biology"
] | 3,480 | [
"Evolutionary biology",
"Human sexuality",
"Behavior",
"Animals",
"Sexuality",
"Animal sexuality",
"Ethology",
"Human behavior"
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49,183,008 | https://en.wikipedia.org/wiki/Lead%20abatement | Lead abatement includes lead-based paint abatement activities, such as inspections, risk assessments, as well as removal. Lead abatement must be performed by educated, certified professionals with proper safety protocols to limit lead exposure. The goal is to permanently eliminate lead-based paint hazards, such as serious permanent and irreversible health damage due to lead poisoning in children. This is especially important in home environments and in any facility with frequent visitation by children, particularly those built before 1978.
Techniques
Residential
There are various lead abatement techniques to remove residential lead-based paint and lead in household dusts. Encapsulation and enclosure makes the hazard of lead-based paint inaccessible, while chemical stripping, removal of abrasives, scraping with the hand, and component replacement are effective in permanently removing lead-based paints from households. Encapsulation refers to the technique that coats all lead-contaminated surfaces with a special liquid coating, which provides a long-lasting and effective barrier and prevents lead dust particles from being released. Enclosure refers to covering all lead-contaminated surfaces and objects with a solid, dust-tight barrier, which is effective in not exposing children to harmful lead paint but is not a permanent solution. Removal is the act of scraping, stripping, vacuuming, and blasting lead-based paint from contaminated surfaces. Replacement is the simple removal and substitution of only objects contaminated with lead, such as lead-painted doors and windows. However, residential lead abatement practices are relatively expensive, and some practices are ineffective and could even worsen the current situation.
Soils
Lead contaminated soil is one of the leading sources of lead poisoning for children in the United States. Soils with lead are especially prominent in urban landscapes and near old homes and child-occupied facilities that were built before 1978 (also known as target housing). Lead can get into soils via deposits from leaded gasoline (which was banned in the United States in 1996 by the Clean Air Act), degradation of leaded paint on nearby paint surfaces, exterior lead-based paint chippings and dust, and industrial sites. It is important that lead contaminated soils be properly disposed as soon as possible. For risk assessment, it is recommended by the US EPA that more than two dust and soil samples are taken. Remediation technologies and methods for lead contaminated soils include excavation and off-site disposal to permanently remove the contaminated soils from the site, containment technologies (such as asphalt capping) to reduce human health exposure and hazards, and traditional techniques (such as washing and stabilizing soil). In addition, it is important that there is a comprehensive nationwide understanding by the people of the hazards and proper removal of lead contaminated soils. Specific, official guidelines for removal or covering of lead-contaminated soil can be found in the US EPA guidance issues in 1994, also known as the Section 403 Guidance.
Lead abatement vs. RRP
Lead abatement and RRP (Renovation, Repair, and Painting) activities are similar in that they are both performed in target housing and child-occupied facilities. In the United States, they are both protected under OSHA 29 CFR 1926.62 and required to post signage in lead-related work areas.
However, even though the activities performed look similar, lead abatement and RRP activities are also very different. Lead abatement is a specialized activity that is performed to permanently eliminate lead-based paint hazards and is usually done based on orders from state or local governments after a serious lead-related incident. Meanwhile, RRP activities are only performed at the discretion and desire of the home or facility owner to temporarily minimize lead-related hazards for aesthetic or lead-unrelated purposes. Lead abatement techniques include encapsulation, enclosure, removal, and/or replacement, while RRP activities include modification or repair of painted doors, surface restoration, window repair, surface preparation that usually produces paint dust, removal of painted building components, cutting holes in painted surfaces to install insulation, and installation of interim controls that disturb existing painted surfaces. Thus, RRP activities are more high risk than lead abatement techniques because they can further disturb the existing lead paint and institute more problems.
Rules and regulations in the United States
Lead abatement, also known as lead-based paint activities, are regulated by the United States Environmental Protection Agency (EPA). Laws and policies involving lead abatement activities are enforced and kept in check by the EPA, local government, and state government. All lead-based paint activities intended by state governments and facility owners must receive proper authorization from the EPA before being carried out. Because working with lead poses health risks and even permanent damage to health, it is important that lead abatement workers, supervisors, inspectors, and other individuals dealing with lead-based paint strictly comply to the following regulations. Individuals performing lead abatement activities in the home environment or child-occupied facilities must be properly trained, take classes, and get certified; training programs providing instruction in such activities must be accredited and approved by the EPA; and these activities must be carried out in accordance to reliable, effective, and safe work practice standards, as defined by OSHA. Improper lead abatement or removal by the incorrect method or by an unlicensed individual can result in severe consequences. If lead abatement is improperly managed or carried out, chips and dust can pose additional health hazards. Furthermore, the current situation can worsen as well. To prevent this, Congress passed the 1992 Residential Lead Based Paint Hazard Reduction Act of 1992, which ensures that contractors are well qualified and properly trained.
Lead-based paints
The production and consumption of lead-based paints is a worldwide issue. Many Asian countries, especially China, depend on the import, export, production, and consumption of paints. However, the paints produced in China and other Asian countries are problematic. Paints used for toys, paint to make finger paint, interior and exterior wall paint, and woodenware paints are all the types of paints produced in Asian countries, particularly China. Many paints contain much more lead content than regulatory standards allow. It is important to note that the regulatory standards can be misleading as well. For example, in China, the safe lead content criteria is based on soluble lead levels, not total lead levels; this can lead to paints being labeled as safe even when they contain harmful concentrations of lead. It was also found in a study that colored paints have more lead concentrations than pure white paints, most likely due to lead being added for additional color enhancement. As such, even with regulatory standards for lead content in paints, there are still paints with lead being produced around the world. It has been observed that paints produced in third world, developing countries contain higher lead content than those produced in first world, developed countries. The production and consumption of lead-based paints is actually growing in developing countries. In these developing countries, many of which do not have the proper resources, personnel, technology, and tools to remove lead from their paints. Thus, many lead-related illnesses and defects, especially in children, are arising in these countries. In order to prevent the detrimental effects of the production and consumption of lead-based paints, the United Nations Environment Program (UNEP) has initiated the Global Alliance to Eliminate Lead Paint to prevent exposure to lead through advocating the phase-out of paints containing lead. Through these kinds of programs, it is important that all countries worldwide understand what lead-based paints are, what the effects and risks of lead-based paints are, what alternatives to lead-based paints there are, and what the proper removal methods and strategies are. Verification of all paint content labels, correct adjustment of regulatory standards and criteria for safe lead content in paints, and awareness and education are crucial in abating lead-based paint and its harmful effects around the world.
See also
Environmental toxicology
History of the tetraethyllead controversy
Lead and crime hypothesis
Organolead chemistry
Pollution control
Lead abatement in the United States
References
External links
Abatement
Pollution control technologies | Lead abatement | [
"Chemistry",
"Engineering"
] | 1,624 | [
"Pollution control technologies",
"Environmental engineering"
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49,183,172 | https://en.wikipedia.org/wiki/Branched%20chain%20amino%20acid%E2%80%93cation%20symporter | The branched chain amino acid:cation symporter (LIVCS) family (TC# 2.A.26) is a member of the APC superfamily. Characterized members of this family transport all three of the branched chain aliphatic amino acids (leucine (L), isoleucine (I) and valine (V)). These proteins are found in Gram-negative and Gram-positive bacteria and function by a Na+ or H+ symport mechanism. They possess about 440 amino acyl residues and display 12 putative transmembrane helical spanners. As of early 2016, no crystal structures for members of the LIVCS family are available on RCSB.
Transport reaction
The generalized transport reaction is:
[L, I or V] (out) + [Na+ or H+] (out) → [L, I or V] (in) + [Na+ or H+] (in).
Proteins
As of early 2016, there are 10 known proteins in the LIVCS family. These can be found in the Transporter Classification Database.
References
Further reading
Braun, Peter R.; Al-Younes, Hesham; Gussmann, Joscha; Klein, Jeannette; Schneider, Erwin; Meyer, Thomas F. (2008-03-01). "Competitive inhibition of amino acid uptake suppresses chlamydial growth: involvement of the chlamydial amino acid transporter BrnQ". Journal of Bacteriology 190 (5): 1822–1830. . . . .
Böhmer, Christine; Rauhut, Oliver W. M.; Wörheide, Gert (2015-07-07). "Correlation between Hox code and vertebral morphology in archosaurs". Proceedings of the Royal Society B: Biological Sciences 282 (1810). . . . .
Trip, Hein; Mulder, Niels L.; Lolkema, Juke S. (2013-01-01). "Cloning, expression, and functional characterization of secondary amino acid transporters of Lactococcus lactis". Journal of Bacteriology 195 (2): 340–350. . . . .
Reizer, J; Reizer, A; Saier, MH Jr. (June 29, 1994). "A functional superfamily of sodium/solute symporters.". 1197(2): (2): 133–66. .
Protein families
Transmembrane transporters
Protein pages needing a picture | Branched chain amino acid–cation symporter | [
"Biology"
] | 531 | [
"Protein families",
"Protein classification"
] |
49,183,304 | https://en.wikipedia.org/wiki/HD%2047366 | HD 47366 is the Henry Draper Catalogue designation for a star in the southern constellation of Canis Major. It has an apparent visual magnitude of 6.12, which puts it near the lower limit of stars visible to the naked eye. According to the Bortle scale, it can be viewed from dark rural skies. Parallax measurements performed by the Gaia spacecraft provide a distance estimate of .
This is a K-type giant star with a stellar classification of K1III: − the colon suffix indicates some uncertainty in the luminosity classification of III. Spectroscopic analysis of the star was used to derive an estimated mass of about 1.81 times the mass of the Sun. It has an estimated age of 1.6 billion years; old enough at that mass to have evolved off the main sequence. As a giant star, the atmosphere has expanded to 7.3 times the Sun's radius, and it is emitting 26 times the solar luminosity at an effective temperature of 4,772 K. The projected rotational velocity of the star is 4.3 km/s, indicating it is rotating with a period of under 86 days.
In 2016, a team of astronomers reported the detection of a pair of giant planetary companions. Radial velocity measurements indicated gravitational perturbations of the star being caused by orbiting objects. The best fit to the preliminary data suggests two periodicities: one almost exactly a year long like the Earth's periodicity, and a second of around two years. Both objects are predicted to have masses greater than that of the planet Jupiter: their minimum masses are 1.8 and 1.9 Jupiter masses, respectively. Until the inclination of their orbits is known, their actual masses cannot be pinned down more accurately.
Modelling of the orbits of the two planets showed that they are dynamically unstable on the life span of their host star unless they are in a 2:1 mean motion resonance or are on mutually retrograde orbits. In 2019, J. P. Marshall and associates proposed an orbital fit with lower eccentricities that is more stable. The new fit is closer to the 2:1 mean motion resonance. As the host star continues to evolve to a larger radius, it is expected that both planets will undergo orbital decay due to tidal forces and be engulfed.
References
External links
K-type giants
Planetary systems with two confirmed planets
Canis Major
2437
BD-12 1566
047366
031674 | HD 47366 | [
"Astronomy"
] | 498 | [
"Canis Major",
"Constellations"
] |
49,183,357 | https://en.wikipedia.org/wiki/Cation-chloride%20cotransporter | The cation-chloride cotransporter (CCC) family (TC# 2.A.30) is part of the APC superfamily of secondary carriers. Members of the CCC family are found in animals, plants, fungi and bacteria. Most characterized CCC family proteins are from higher eukaryotes, but one has been partially characterized from Nicotiana tabacum (a plant), and homologous ORFs have been sequenced from Caenorhabditis elegans (worm), Saccharomyces cerevisiae (yeast) and Synechococcus sp. (blue green bacterium). The latter proteins are of unknown function. These proteins show sequence similarity to members of the APC family (TC #2.A.3). CCC family proteins are usually large (between 1000 and 1200 amino acyl residues), and possess 12 putative transmembrane spanners (TMSs) flanked by large N-terminal and C-terminal hydrophilic domains.
Function
CCC family proteins can catalyze NaCl/KCl symport, NaCl symport, or KCl symport depending on the system. The NaCl/KCl symporters are specifically inhibited by bumetanide while the NaCl symporters are specifically inhibited by thiazide. One member of the CCC family, the thiazide-sensitive NaCl cotransporter (NCC) of man is involved in 5% of the filtered load of NaCl in the kidney. Mutations in NCC cause the recessive Gitelman syndrome. NCC is a dimer in the membrane. It is regulated by RasGRP1.
Transport reaction
The generalized transport reaction for CCC family symporters is:
{Na+ + K+ + 2Cl−} (out) ⇌ {Na+ + K+ + 2Cl−} (in).
That for the NaCl and KCl symporters is:
{Na+ or K+ + Cl−} (out) ⇌ {Na+ or K+ + Cl−} (in).
Structure
NCC proteins are dimers in the membrane and contain 12 TMSs.
Two splice variants of NKCC2 are identical except for a 23 aa membrane domain. They have different affinities for Na+, K+ and Cl−. This segment (residues 216-233 in NKCC2) were examined for ion selectivity. Residue 216 affects K+ binding while residue 220 only affects Na+ binding. These two sites are presumed to be adjacent to each other.
Each of the major types of CCC family members in mammals exist as paralogous isoforms. These may differ in substrates transported. For example, of the four currently recognized KCl transporters, KCC1 and KCC4 both recognize KCl with similar affinities, but KCC1 exhibits anion selectivity: Cl− > SCN− = Br− > PO > I−, while KCl4 exhibits anion selectivity: Cl− > Br− > PO = I− > SCN−. Both are activated by cell swelling under hypotonic conditions. These proteins may cotransport water (H2O).
CCCs share a conserved structural scaffold that consists of a transmembrane transport domain followed by a cytoplasmic regulatory domain. Warmuth et al. (2009) determined the x-ray structure of the C-terminal domain of a CCC from the archaeon Mehanosarcina acetivorans (). It shows a novel fold of a regulatory domain, distantly related to universal stress proteins. The protein forms dimers in solution, consistent with the proposed dimeric organization of eukaryotic CCC transporters.
See also
APC Superfamily
SLC12A9
SLC12A8
Chloride potassium symporter 5
Transporter Classification Database
References
Protein families
Solute carrier family | Cation-chloride cotransporter | [
"Biology"
] | 824 | [
"Protein families",
"Protein classification"
] |
49,183,929 | https://en.wikipedia.org/wiki/Missing%20stair | The missing stair is a metaphor for a person within a social group or organization who many people know is untrustworthy or otherwise has to be "managed," but around whom the group chooses to work by discreetly warning newcomers of their behavior, rather than address the person and their behavior openly. The "missing stair" in the metaphor refers to a dangerous structural fault, such as a missing step in a staircase; a fault that people may become used to and quietly accepting of, that is not openly signposted or fixed, and that newcomers to a group or organization are warned about discreetly.
Origins
The phrase was coined by blogger Cliff Jerrison in a 2012 post on The Pervocracy, a blog about BDSM and kink. Describing a man in his social circle known to be a rapist, Pervocracy wrote:
People had gotten so used to working around this guy, to accommodating his "special requirements," that they didn't feel like there was an urgent problem in their community. They did eventually expel him, but it was after months of it being widely shared knowledge that he was a rapist. [...] I think there were some people in the community who were intentionally protecting him, but there were more who were de facto protecting him by treating him like a missing stair. Like something you're so used to working around, you never stop to ask "what if we actually fixed this?" Eventually you take it for granted that working around this guy is just a fact of life, and if he hurts someone, that's the fault of whoever didn't apply the workarounds correctly.
Jerrison intended the term to apply beyond sexually predatory behavior, including, for example, underperforming colleagues who let others pick up their slack. While "missing stair" has most often been used in the context of sexual misconduct, it may describe a variety of uncomfortable social or professional circumstances.
Meaning
The analogy of the missing stair makes it clear that the problem is the predator (the missing stair) and that the solution is stopping the predatory behavior (fixing the stair).
An article about industry sexual harassment on comics news site ComicsAlliance posed the question: "Which one of these statements makes more sense to say: 'These people need to find more ways to stop people from harming them.' OR: 'These people should stop causing harm.' If you ever find yourself saying the former instead of the latter, take a moment and ask yourself why."
In a 2014 post on the anti-rape blog Yes Means Yes, lawyer Thomas MacAulay Millar wrote that the missing stair analogy was consistent with his understanding of rapists' motivations and behaviors, based on research carried out by clinical psychologists David Lisak and Paul M. Miller, and by Stephanie K. McWhorter, a researcher with the U.S. Naval Health Research Center. Millar wrote that while a small number of rapists are "one-timers" who may be making a mistake or are confused about consent, the majority are repeat offenders, averaging six rapes each. "We need to spot the rapists," Millar wrote, "and we need to shut down the social structures that give them a license to operate. They don't accidentally end up in a room with a woman too drunk or high to consent or resist; they plan on getting there and that's where they end up."
Usage
The analogy has been picked up and used in communities related to paganism, comics, punk, geek culture, and in Tavi Gevinson's Rookie, a magazine for teenage girls. It has been used by advice columnists, including Captain Awkward and Sam W. at Scarleteen.
Geek culture site The Mary Sue referenced the concept in 2013, in a story celebrating science fiction writer John Scalzi's announcement that he would no longer attend science fiction conventions that did not have clear and prominent sexual harassment policies. In 2014, Feministe quoted science fiction editor Michi Trota describing James Frenkel, who was permanently banned from attending Wiscon after harassment complaints, as "someone who has been an industry missing stair for decades."
In 2014, Yes Means Yes compared disgraced former broadcaster and pop musician Jian Ghomeshi to a missing stair, and urged the BDSM community to distance themselves from him.
In 2015, the missing stair concept was invoked by The Guardian in its coverage of American astronomer Geoffrey Marcy's resignation from his professorship at UC Berkeley, following its finding that he had repeatedly violated the university's sexual harassment policy between 2001 and 2010. In 2015, after pornographic film actress Stoya accused her colleague and former boyfriend James Deen of rape, prompting similar allegations by a dozen other women, feminist site We Hunted the Mammoth wrote that James Deen seemed to be "a perfect example" of a missing stair.
The concept has also been discussed in reference to religion in the workplace, such as a coworker who repeatedly skirts the line of evangelizing to their colleagues, and who everyone in the workplace simply works around. In a post on the employment issues blog Ask A Manager, a reader wrote in to ask about how to handle a colleague who repeatedly asked personal questions about their faith or lack thereof, but who received no disciplinary action or reproachment. Rather, the reader described the colleague in question as the "company's personal Michael Scott and everyone kind of worked around him as a missing stair."
On NPR, in a review of the 2015 Jo Walton science fiction/fantasy novel The Just City, reviewer Amal El-Mohtar argued that Walton deliberately included missing stairs in her book, in an effort to reflect current discourse around the topic.
In 2017, adult performer Jessica Drake gave an interview to Rolling Stone, and commented regarding the allegations surrounding colleague and fellow performer Ron Jeremy: "I have viewed [Ron Jeremy] as the missing stair in the adult community."
See also
Bus factor
Open secret
Walter Breen
Harvey Weinstein
References
Concepts in social philosophy
Deviance (sociology)
Sexual abuse
Social agreement
Social phenomena | Missing stair | [
"Biology"
] | 1,245 | [
"Deviance (sociology)",
"Behavior",
"Human behavior"
] |
49,185,980 | https://en.wikipedia.org/wiki/Emission%20channeling | Emission channeling is an experimental technique for identifying the position of short-lived radioactive atoms in the lattice of a single crystal.
When the radioactive atoms decay, they emit fast charged particles (e.g., α-particles and β-particles). Because of their charge, the emitted particles interact in characteristic ways with the electrons and nuclei of the crystal atoms, giving rise to channeling and blocking directions for the particle escaping the crystal. The intensity (or yield) of the emitted particles is therefore dependent on the position of the detector relative to crystal planes and axes. This fact is used to infer the location of the radioactive species in the lattice by varying the emission angles and subsequent comparison to simulation results. For the simulations, the manybeam formalism can be employed, and resolutions below 1 Å are achievable.
Among others, the technique has been used to determine the sites of manganese impurities implanted in semiconducting gallium arsenide: 70% occupy substitutional gallium sites and 28% are located at tetrahedral interstitial sites with arsenic as nearest neighbors.
See also
Channelling (physics)
References
External links
Radioactivity
Experimental physics | Emission channeling | [
"Physics",
"Chemistry"
] | 241 | [
"Experimental physics",
"Radioactivity",
"Nuclear physics"
] |
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