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70,730,526 | https://en.wikipedia.org/wiki/5%2C6-Dibromo-N-methyltryptamine | 5,6-Dibromo-N-methyltryptamine (5,6-Dibromo-NMT) is a substituted tryptamine alkaloid that occurs naturally in marine sponges.
See also
5,6-Dibromotryptamine
6-Bromotryptamine
5-Bromo-DMT
References
Tryptamine alkaloids
Bromoarenes | 5,6-Dibromo-N-methyltryptamine | [
"Chemistry"
] | 82 | [
"Tryptamine alkaloids",
"Alkaloids by chemical classification"
] |
70,730,584 | https://en.wikipedia.org/wiki/Amanita%20yema | Amanita yema is a species of fungus in the genus Amanita, family Amanitaceae. The fungi can be identified by its pileus color of a red center that gradually fades into a yellow-hued edge. Growing only in forest outskirts in Mexico, the fungus is a critical member of the plant biome as it is a mycorrhizal fungi.
Taxonomy
Amanita yema was identified as a species of fungus in 2001 by Guzmán & Ram.-Guill. It was soon categorized under the taxa: Amanita caesarea complex
Description
Standing tall with a pileus that fades from a red center to a yellow margin, this fungus stands out. With a base that ranges from a white/yellow color to an orange colored stem. Its gills, or lamelle, is also described to have a white or yellow tint. Stemming out of the soil, the fungus is often found around forest edges in Mexico. The fungus is said to have a mild odor and taste, but is pleasantly enjoyed.
Habitat and distribution
This mushroom is found in most temperate forests in Mexico and is locally used by its natives. It strives with being locally in demand, be that in the rural areas' markets or in major cities. There is a demand for this fungus in Italy, but no trade has been made with Mexico. As part of the Amanita caesarea complex, it is deemed to have a high cultural significance in Ixtlan.
Edibility
This mushroom is deemed to be wild edible fungus, and are said to have a pleasant taste. It is almost always consumed with other mushrooms and meat. Although with its simplicity and rather small size, many eat the mushroom by its self. With a simple light washing with water it is ready to be cooked. It is however, a species of fungi that is avoided, as it is similar in appearance to the toxic fungal specie Amanita muscaria. Its local abundance is low, which increases its worth both locally and globally.
Medicinal uses
Among the Amanita caesarea complex, A. yema is in high demand for its medicinal uses. It is frequently prepared as an anti-inflammatory agent. There are other treatments the mushroom can be used for. Acting as a gastrointestinal treatment, the mushroom is boiled and its cooking water is consumed at room temperature, for renal problems.
References
yema
Fungus species
Fungi of Mexico
Taxa named by Gastón Guzmán | Amanita yema | [
"Biology"
] | 492 | [
"Fungi",
"Fungus species"
] |
70,730,802 | https://en.wikipedia.org/wiki/Nickel%28II%29%20perchlorate | Nickel(II) perchlorate is a collection of inorganic compounds with the chemical formula of . Its colors of these solids vary with the degree of hydration. For example, the hydrate forms cyan crystals, the pentahydrate forms green crystals, but the hexahydrate (Ni(ClO4)2·6H2O) forms blue crystals. Nickel(II) perchlorate hexahydrate is highly soluble in water and soluble in some polar organic solvents.
Preparation
Aqueous solutions of nickel(II) perchlorate can be obtained by treating nickel(II) hydroxide, nickel(II) chloride or nickel(II) carbonate with perchloric acid.
Ni(OH)2 + 2HClO4 + 4H2O → Ni(ClO4)2·6H2O
Two hydrates have been characterized by X-ray crystallography: the hexahydrate and the octahydrate. Several other hydrates are mentioned including the pentahydrate, which is claimed to crystallize at room temperature, the nonahydrate, which is claimed to crystallize at −21.3 °C, a tetrahydrate, and a monohydrate.
The yellow anhydrous product is obtained by treating nickel(II) chloride with chlorine trioxide. As deduced by X-ray crystallography, Ni resides in a distorted octahedral environment and the perchlorate ligands bridge between the Ni(II) centers.
Applications
Nickel(II) perchlorates has few practical uses.
Other compounds
Ni(ClO4)2 also forms some compounds with NH3, such as Ni(ClO4)2·6NH3 which is a light purple crystal.
Ni(ClO4)2 also forms some compounds with N2H4, including Ni(ClO4)2·2N2H4 as a light positive solid or Ni(ClO4)2·5N2H4 which are purple crystals.
Ni(ClO4)2 forms compounds with CO(NH2)2, like Ni(ClO4)2·6CO(NH2)2 which is a yellow-green solid.
Ni(ClO4)2 forms compounds with CON3H5, for example Ni(ClO4)2·3CON3H5 which is a blue solid.
Ni(ClO4)2 forms compounds with CON4H6, such as Ni(ClO4)2·3CON4H6 which is an explosive blue crystal with a bulk density of 0.95 g/cm³.
Ni(ClO4)2 can also form compounds with CS(NH2)2, such as Ni(ClO4)2·6CS(NH2)2 which is a pale green solid.
Ni(ClO4)2 also forms some compounds with CSN3H5, such as Ni(ClO4)2·2CSN3H5·3H2O which is a blue paramagnetic crystal or Ni(ClO4)2·3CSN3H5·2H2O which is a dark positive crystal.
Ni(ClO4)2 also forms some compounds with pyridine.
Further reading
See also
Nickel
Perchloric acid
References
Oxidizing agents
Nickel compounds
Perchlorates | Nickel(II) perchlorate | [
"Chemistry"
] | 707 | [
"Perchlorates",
"Redox",
"Oxidizing agents",
"Salts"
] |
70,730,840 | https://en.wikipedia.org/wiki/Salbostatin | Salbostatin is an antibiotic and trehalase inhibitor with the molecular formula C13H23O8. Salbostatin is produced by the bacterium Streptomyces albus.
See also
Pseudouridimycin
References
Further reading
Salbostatin
Polyols
Secondary amines
Amino sugars | Salbostatin | [
"Chemistry",
"Biology"
] | 65 | [
"Amino sugars",
"Carbohydrates",
"Biotechnology products",
"Organic compounds",
"Antibiotics",
"Biocides",
"Organic compound stubs",
"Organic chemistry stubs"
] |
70,730,914 | https://en.wikipedia.org/wiki/Psammophyte | A psammophyte is a plant that grows in sandy and often unstable soils. Psammophytes are commonly found growing on beaches, deserts, and sand dunes. Because they thrive in these challenging or inhospitable habitats, psammophytes are considered extremophiles, and are further classified as a type of psammophile.
Etymology
The word "psammophyte" consists of two Greek roots, psamm-, meaning "sand", and -phyte, meaning "plant". The term "psammophyte" first entered English in the early twentieth century via German botanical terminology.
Description
Psammophytes are found in many different plant families, so may not share specific morphological or phytochemical traits. They also come in a variety of plant life-forms, including annual ephemerals, perennials, subshrubs, hemicryptophytes, and many others. What the many diverse psammophytes have in common is a resilience to harsh or rapidly fluctuating environmental factors, such as shifting soils, strong winds, intense sunlight exposure, or saltwater exposure, depending on the habitat. Psammophytes often have specialized traits, such as unusually tenacious or resilient roots that enable them to anchor and thrive despite various environmental stressors. Those growing in arid regions have evolved highly efficient physiological mechanisms that enable them to survive despite limited water availability.
Distribution and habitat
Psammophytes grow in regions all over the world and can be found on sandy, unstable soils of beaches, deserts, and sand dunes. In China's autonomous Inner Mongolia region, psammophytic woodlands are found in steppe habitats.
Ecology
Psammophytes often play an important ecological role by contributing some degree of soil stabilization in their sandy habitats. They can also play an important role in soil nutrient dynamics. Depending on the factors at play at a given site, psammophyte communities exhibit varying degrees of species diversity. For example, in the dunes of the Sahara Desert, psammophyte communities exhibit limited diversity and are predominantly made up of plants from the grass and mustard families.
Like many other types of plants, psammophytes can have symbiotic relationships with microorganisms called endophytes that live inside of their tissues, which can impart enhanced growth or other benefits.
Conservation
A major threat to psammophytes in many regions is dune destabilization, which is exacerbated by human development projects and factors associated with climate change, such as drought and temperature increases. Encroachment of non-psammophytic plants and invasive species poses another threat to psammophyte species in some areas. Ecological restoration efforts in psammophyte habitats often aim to utilize the natural soil stabilizing and nutrient enhancement abilities of psammophytes as part of restoration strategies. Another important strategy is restoring and protecting the requisite soil microbiome some psammophytes require to thrive.
China's Minqin Garden of Desert Plants is one organization that is actively working on efforts to conserve both wild and horticultural psammophyte species.
Examples
Some examples of psammophyte species include:
Agriophyllum squarrosum (sand rice)
Haloxylon ammodendron (saxaul)
Linaria arenaria (sand toadflax)
Omphalodes kuzinskyanae (Kuzinsky navelwort)
Stipagrostis pungens (madjiugu)
Corynephorus canescens (grey hair-grass or gray clubawn grass)
Plantago arenaria (branched plantain, sand plantain, or black psyllium)
See also
Psammophile
Extremophile
Goravan Sands Sanctuary
References
External links
Minqin Garden of Desert Plants
Plant morphology
Biology terminology
Plant life-forms
Plants by habit
Desert flora | Psammophyte | [
"Biology"
] | 817 | [
"Plants",
"Desert flora",
"Plant morphology",
"nan",
"Flora",
"Plant life-forms"
] |
70,730,937 | https://en.wikipedia.org/wiki/Barbara%20E.%20Jones | Barbara E. Jones (Dec 19, 1944 - July 22, 2022) was an American-Canadian neuroscientist whose research concerns the chemical and neurological basis for the circadian alternation between sleep and wakefulness. Jones has been described as "a central contributor to our understanding of the brain basis of REM sleep". She was a professor emerita in the McGill University Department of Neurology and Neurosurgery, associated with the Montreal Neurological Institute and Hospital.
Education and career
Jones was a student at the University of Delaware, earning a bachelor's degree in psychology in 1966, a master's degree in physiological psychology in 1969, and a Ph.D. in physiological psychology in 1971.
She joined the McGill University faculty as a professor in the Department of Neurology and Neurosurgery at the Montreal Neurological Institute and Hospital in 1977. During her career, Jones studied how the brain generates waking and sleep states using immunohistochemical and neuroanatomical techniques combined with neurophysiological recording, and optogenetics. Amongst many important findings, Jones identified the modulatory action of cholinergic neurons on cortical activation, the influence of inhibitory GABA neurons on sleep states and the activity of hypocretins/orexins neurons as key regulators of waking and narcolepsy with cataplexy in humans and animals.
Recognition
Jones was elected as a Fellow of the Royal Society of Canada in 2010.
The Montreal Neurological Institute and Hospital held a symposium on sleep in 2021, in honour of Jones's career and retirement.
References
External links
Living people
Canadian neuroscientists
Canadian women neuroscientists
Sleep researchers
University of Delaware alumni
Academic staff of McGill University
Fellows of the Royal Society of Canada
1944 births | Barbara E. Jones | [
"Biology"
] | 369 | [
"Sleep researchers",
"Behavior",
"Sleep"
] |
70,731,025 | https://en.wikipedia.org/wiki/5%2C6-Dibromo-DMT | 5,6-Dibromo-DMT (5,6-Dibromo-N,N-dimethyltryptamine, 5,6-Br-DMT) is a substituted tryptamine alkaloid found in some marine sponges. It is briefly mentioned in Alexander Shulgin's book TiHKAL (Tryptamines I Have Known and Loved) under the DMT entry and is stated to be found, along with other tryptamines, in Smenospongia aurea and other sponges.
See also
5,6-Dibromo-N-methyltryptamine
6-Bromotryptamine
5-Bromo-DMT
References
Tryptamine alkaloids
Bromoarenes
Dimethylamino compounds | 5,6-Dibromo-DMT | [
"Chemistry"
] | 162 | [
"Tryptamine alkaloids",
"Alkaloids by chemical classification"
] |
70,732,988 | https://en.wikipedia.org/wiki/Maryam%20Omar | Maryam Osama Khalil Omar (born 8 March 1993) is a Kuwaiti-Palestinian engineer and cricketer who plays for the Kuwait women's national cricket team as a right-handed batting all-rounder. She has also captained the national team. Born and raised in Kuwait, Omar is a Palestinian, and has been described as a "global grand tour all on her own"; she was educated in a Pakistani school in Kuwait, and also in Melbourne, Australia, where she now lives.
Early life and education
Kuwait
Omar was born in Kuwait to mother Salwa and father Osama. She has three sisters, Amal, Zuhoor and Budoor. From an early age, she participated in a variety of sports, including basketball, gymnastics, judo, martial arts and swimming. She does not really remember whether her first baby steps were on land or in water: "My father's love for swimming had a big impact on me and I even competed at club levels in swimming tournaments." She has also said that her mother "did a great job in making me tough", and that it was for her mother that she attained a black belt in karate.
In 2010, aged 17, Omar was introduced to cricket at her Pakistani school in Kuwait. The national cricket board was targeting a number of schools to try to recruit girls to play the game. "My sports teacher came and told me that Kuwait Cricket was looking for girls to play in the Under-19 Asia Cup, and I said, 'What is cricket?'", she told Abu Dhabi-based newspaper The National in 2022. With encouragement from her mother, who suggested that she might ultimately make the national team, "I rocked up and was the only Arab in the side. I thought it might be hard for me to learn the game, but the coaches were so supportive." Before long, she was loving cricket, and had become so dedicated to learning it that she stopped following other sports.
When Omar started out as a cricketer, she found that her first name, which is very common in the Arab world, created a difficulty. So many other cricketers had the same first name that every time someone called out to her, "seven heads would turn around and I would get really confused." Omar therefore decided to adopt a unique nickname. She chose "MOKO", which is made up of the first letters of her full name. Her first preference shirt number is 25, which she believes is her lucky number.
Omar was also confronted with two other difficulties. First, cricket is seldom discussed in the Arab world, even though it is popular in Kuwait, where about 1.5 million of the total population of four million is made up of expats from Test-playing nations, including almost one million Indians. When Omar started playing cricket, her parents had never even heard of it. Although Omar, as a pupil of a Pakistani school, already had a vague awareness of the game, she neither understood the rules very much, nor knew how big it was. However, her coaches, Tariq Rasool and Tahir Khan, taught her all the cricket skills she needed, and even advised her to learn about the game by watching it on television.
Omar also trained for at least three hours daily, and attended umpiring and coaching courses organised by Cricket Kuwait. She watched videos of matches at Sharjah Cricket Stadium, and AB de Villiers of South Africa became her hero. Her parents, after observing her hard work, were supportive, even though they still do not really understand or relate to the game.
Secondly, and as Omar herself has put it, "Playing competitive sport is not a traditional role for women in the Middle East." Omar says that it is not easy for girls from the region to pursue a career in or passion for sport, and that none of her three sisters even play any sports. Instead, her sisters conform to social expectations by enjoying cooking, fashion, shopping and socialising with friends at home, and think that sports are for boys. "My sisters call me the tomboy", she told The National. In that context, Omar's father initially had difficulty in accepting her sporting aspirations, especially as they had the potential to take her away from her family. Although he eventually came around, he warned her that she would have to give up the game if it adversely affected her studies, and imposed a strict curfew of 9:00 pm, as in Arab culture it is not acceptable for girls to be out late. According to Omar, "It is good to have a strict dad because I have learnt to manage my time and push my limits."
After leaving school in 2010, Omar studied at the Australian College of Kuwait (ACK) for a Bachelor of Engineering Technology in civil and structural engineering. She completed that degree with "straight As" and "a perfect GPA" in 2014, and then worked for two years as a structural engineer in Kuwait. At that time, she first saw women playing franchise team cricket, when she happened, while visiting a cricket equipment shop in Kuwait, to see a broadcast of a match in Australia's domestic T20 competition, the WBBL. The experience led her to dream about playing for a WBBL team.
Australia
Omar's coaches in Kuwait, all of them Pakistanis or Indians, had already made her aware that Australia was arguably cricket's No 1 destination. Largely in pursuit of her WBBL dream, she submitted what has been described as "an impressive application" for a master's academic scholarship from the ACK to study at partner university CQUniversity in Australia, and was awarded the inaugural scholarship. Initially, she was to have been sent to Rockhampton in Queensland, but she specifically asked to study in Melbourne, because "it's the home of cricket".
Omar arrived in Melbourne, and began her master's in civil engineering, in 2016. The university contacted local cricket clubs, and she began playing for Essendon Maribyrnong in the 2016/17 season. While studying in Melbourne, she had more time to spend on cricket training. She also worked with Cricket Victoria as cricket development coordinator to drive female participation, and as a bridge engineer (intern) at pitt&sherry, an engineering consultancy. Since completing her master's in 2018, she has continued to live in Melbourne.
Domestic career
Kuwait
On 19 October 2013, Omar captained Kuwait Blue, one of three teams involved in a full-day women's domestic tournament held at Sulaibiya turf ground in Kuwait. After leading her team to victory in the round robin matches against Kuwait Red and Kuwait Green, and to a nine wicket loss to Kuwait Red in the final, Omar shared the best batswomen of the tournament award with Amna Sharif.
Australia
Omar spent her first two cricket seasons in Melbourne, 2016/17 and 2017/18, at Essendon Maribyrnong Park Ladies Cricket Club, the oldest women's cricket club in the world. In both seasons, she played for both the Firsts and Reserves teams; in the former team, her teammates included then and future Australian players Molly Strano and Georgia Wareham, respectively, and State and WBBL player Makinley Blows. She also played for Port Melbourne in men's cricket competitions.
During Omar's first Australian season, "I was completely out of my comfort zone, new to the country, culture and did not know my way around public transport." In particular, the environment in which cricket was played was very different, and the standards of the players were very high. Omar's best performance in the Essendon Maribyrnong Firsts team was a top score for the team of 24 in a T20 match against Box Hill; she was also a member of the Premiership-winning Firsts One Day team. The statistics for her second season were markedly better, especially in the Firsts One Day competition.
Ahead of the 2018/19 season, Omar was recruited by Dandenong, which wanted an experienced player to augment its young squad. The move also gave Omar more opportunities to play in the Firsts competitions. To attend weekday after-work training but avoid peak hour road traffic, she would drive to Dandenong early in the morning, and catch a train to and from work in the Melbourne CBD. At the end of her first season at Dandenong, she was part of a team including Sophie Molineux, Nicole Faltum and Kim Garth that defeated a Essendon Maribyrnong team including Strano, Wareham, Blows, and former Australian player Kristen Beams, in the Firsts T20 grand final. In her three seasons at Dandenong, she also achieved consistent highest One Day match scores, of 42, 49 and 44*, respectively.
Omar then moved to the newly rebadged Carlton team for the 2021/22 season. Carlton was similarly seeking to bolster an inexperienced squad. Omar's first season there was less successful, with a highest One Day match score of 34 towards the end of the summer. She also played some further men's matches for Port Melbourne.
International career
2010–2019: Early years
Omar was first selected for the Kuwait national team squad in 2010, the same year she took up the game. The national squad travelled to Singapore to play in a tournament, and she therefore had to skip the first two weeks of her first semester in college. Her father was not amused. She was also still very inexperienced: "I played for two years for the Kuwaiti side without understanding the rules much. I was really just an expert fielder, like, 'See ball, catch ball, she has since told The National.
In 2013, ahead of the ACC U19 Championship in Thailand, Omar was appointed as captain of the team. Although she thought at that time that her cricket knowledge was not up to the mark, she had been hoping for the captain's role when she felt she was ready. During that tournament, she scored her first international half century, in an innings in which she was unbeaten.
The following year, 2014, Omar was player of the tournament at the GCC Women's T20 Championship in Oman, in which Kuwait finished second. In 2015, she was again player of the tournament, and also led her team to its first ever tournament victory, in the Chiang Mai 3rd ladies championship in Thailand. By the middle of 2016, she considered herself to be as one of the top female cricketers in the Gulf region. In December 2016, after her move to Melbourne, she was named as best batswoman at the UAE International Women's T20 tournament in Sharjah.
2019–present: WT20I career
On 18 February 2019, Omar made her Women's Twenty20 International (WT20I) debut for, and captained, Kuwait against Malaysia, in the second match of the 2019 ICC Women's Qualifier Asia, held in Bangkok, Thailand. The match was also Kuwait's first ever WT20I. Malaysia won the match, by 63 runs. Omar's best individual performance during the tournament was on 27 February 2019, in Kuwait's match against Nepal; she top scored for that match with 29 runs in 36 balls, and also took 2/24. However, Kuwait lost the match by 30 runs, and finished the tournament in last place, after losing all of its matches.
In January 2020, Kuwait participated in, and won, the Qatar Women's T20I Triangular Series in Doha, Qatar, but Omar was not involved in that tournament. In her absence, the Kuwait squad was captained by Amna Tariq.
In November 2021, Omar returned to the team for the ICC Women's T20 World Cup Asia Qualifier in Dubai, United Arab Emirates, but Tariq retained the captaincy. Omar played in all five of Kuwait's matches in the tournament, and topped the team's batting aggregates and averages with 107 runs at 26.75, but the team again lost all of its matches, and finished in last place.
Kuwait's and Omar's next WT20Is were during the GCC Women's Gulf Cup, held in Muscat, Oman, in March 2022. In a contest between six teams, Kuwait managed to finish in fourth place, with victories against both Qatar and Saudi Arabia. During the tournament, Omar once again played in all five of Kuwait's matches and topped the team's aggregates and averages, this time with 145 runs at 36.25. Her best all-round performance was on 22 March 2022, against Qatar: she took 4/14, scored 40 runs in 44 balls, and was awarded player of the match. Kuwait won that match, by 9 wickets, but three days later lost to Bahrain by six wickets, even though Omar had racked up her highest T20I score to date, with 54 runs in 47 balls.
FairBreak career
In May 2022, Omar played in the privately-run 2022 FairBreak Invitational T20 in Dubai, United Arab Emirates. She was allocated to the Sapphires team.
Playing style
Omar is a right handed batting all-rounder. Her preferred batting position is number four in the order, and she bowls off spin. She sees herself as an aggressive player who nevertheless seeks to play according to the situation. In Kuwait, where she learned the game, women play only the T20 format. She was therefore trained to go out hard to gain advantage of the power play.
In Melbourne, women play both T20 and 50 over format matches, and Omar took some time to adjust to the latter format.
For religious reasons, Omar wears a Muslim head-covering, a hijab, both on and off the cricket field. She decided to become a hijab wearer when she was 15 years old. Prior to taking the field at cricket matches, she dons a fast-wicking sports hijab. "For sport, I like the hijab a little tighter so I can run and dive around, and do all that cool stuff", she has said.
Other activities
Since completing her master's degree, Omar has continued to work for pitt&sherry. Initially, she was a structural engineer, engaged in temporary works on the West Gate Tunnel project. Between 2019 and 2021, she was a civil/structural engineer, and since 2021 she has focused on civil engineering.
See also
List of Kuwait women Twenty20 International cricketers
References
External links
Our Student's Success Story – video of Omar describing her CQUni study experience
Profile of Maryam Omar – video by Seven Network, Australia
Living people
1993 births
21st-century Kuwaiti women
21st-century Kuwaiti people
21st-century Palestinian sportswomen
21st-century women engineers
Kuwaiti people of Palestinian descent
Kuwaiti sportswomen
Kuwaiti women engineers
Palestinian engineers
Palestinian expatriate sportspeople in Australia
Structural engineers
Kuwaiti women cricketers
Kuwait women Twenty20 International cricketers | Maryam Omar | [
"Engineering"
] | 3,038 | [
"Structural engineering",
"Structural engineers"
] |
70,734,221 | https://en.wikipedia.org/wiki/Institut%20f%C3%BCr%20Kunststoffverarbeitung | The Institut für Kunststoffverarbeitung in Industrie und Handwerk (IKV), the Institute for Plastics Processing in Industry and Trade at the Rheinisch-Westfälische Technische Hochschule Aachen, Germany, is a teaching and research institute for the study of plastics technology. It stands for practice-oriented research, innovation and technology transfer. The focus of the IKV is the integrative view of product development in the material, construction and processing sectors, in particular in plastics and rubber. The sponsor is a non-profit association that currently includes around 300 companies from the plastics industry worldwide (as of December 2018) and through which the institute maintains a close connection between industry and science. In addition, the IKV is a member of the (AiF).
The institute was founded in 1950 and, with around 350 employees, has become Europe's largest research and training institute in the field of plastics technology. The first head of the institute was , followed in 1959 by Alfred Hermann Henning. From 1965 to 1988 headed the institute, followed by until his retirement in 2011. Since 2011, the current head of the institute, and at the same time managing director of the association, is . He also holds the Chair for within the Faculty of Mechanical Engineering at RWTH Aachen University.
Tasks
The tasks of the institute are:
scientific and practice-oriented research in the field of plastics technology
the training of students to become qualified junior staff for the plastics industry
the training of practitioners in the craft industry in the field of plastics technology
Structure
The scientific departments injection molding/PUR technology, extrusion and further processing, molded part design/materials engineering and fibre-reinforced plastics are the operative units of the institute. The (KAP) (English: Center for Plastics Analysis and Testing) at the IKV supports and advises scientific departments and is available as a service for the industry to solve problems. The training and education department is responsible nationwide for technology transfer to the skilled trades sector.
Since 1960, the institute has been cooperating with the (GFA, English: commercial development agency) in the training center of the (HWK), which served and was certified as a training center for plastics technology for both the IKV and the (DVS) and the (DVGW). On the initiative of the incumbent HWK President , this was transferred in 1983 to the (BGE) in Aachen's Tempelhofer Straße.
Currently, about 130 employees including some 80 scientists are working at the IKV in research, development and training. They are supported by about 220 student assistants. In addition to the tasks mentioned above, one of the goals of the IKV is to provide the industry with solutions to practical problems. Individual projects, but also those within the framework of often lead to high-quality product ideas and developments, which, in the sense of the desired technology transfer, benefit not only larger, but foremost small and medium-sized enterprises.
References
External links
Website of the Institute for Plastics Processing
Research institutes in Germany
Research institutes established in 1950
Plastics industry
Plastics applications
Materials science
Engineering disciplines | Institut für Kunststoffverarbeitung | [
"Physics",
"Materials_science",
"Engineering"
] | 637 | [
"Applied and interdisciplinary physics",
"Materials science",
"nan"
] |
70,734,569 | https://en.wikipedia.org/wiki/36%20Camelopardalis | 36 Camelopardalis is a single star in the northern circumpolar constellation of Camelopardalis. It is visible to the naked eye as a dim point of light with an apparent visual magnitude of +5.3. Parallax measurements provide a distance estimate of approximately 710 light years away from the Sun, and it is drifting away from the Earth with a radial velocity of −1.15 km/s.
36 Camelopardalis has a stellar classification of K1 III-IIIb, which indicates that it is a K-type giant star with a mild underabundance of CH molecules in its spectrum. At present it has 1.24 times the mass of the Sun but has expanded to an enlarged diameter of . It shines at from its photosphere at an effective temperature of , giving it an orange glow. 36 Cam's metallicity is around solar level and spins slowly with a projected rotational velocity of .
References
Camelopardalis
Durchmusterung objects
Camelopardalis, 36
041927
029490
2165
K-type giants | 36 Camelopardalis | [
"Astronomy"
] | 223 | [
"Camelopardalis",
"Constellations"
] |
70,735,144 | https://en.wikipedia.org/wiki/Vanessa%20Wood | Vanessa Claire Wood (born 25 February 1983) is an American engineer who is a professor at the ETH Zurich. She holds a chair in Materials and Device Engineering and serves as Vice President of Knowledge Transfer and Corporate Relations.
Early life and education
Wood earned her bachelor's degree in physics at Yale University. She moved to Massachusetts Institute of Technology for her graduate studies, where studied electrical engineering. She remained at MIT for graduate research, where she researched quantum dots in metal oxide structures with Vladimir Bulimic. Her research developed strategies to integrate colloidal quantum dots in optoelectronic devices. She created three light-emitting diodes where air-stable metal oxides were used to surround the quantum dot active layers. This can improve the shelf-life and luminance of the light-emitting diodes. She also demonstrated the world's first inorganic quantum dot displays incorporating metal oxide charge transport layers. After earning her doctorate, she worked for a short while as a postdoctoral research with Yet-Ming Chiang. She focused on lithium-ion battery flow cells.
Research and career
In 2011, Wood joined the faculty at ETH Zurich. Her research considered lithium-ion batteries, and how electrode microstructure impacts battery efficiency. She created a new analytical method which can be used to monitor battery electrodes during the manufacturing process. She was awarded a European Research Council starting grant to develop quantitative metrologie to guide lithium-ion battery manufacturing.
Wood founded the spin-off company Battrion in 2015. Battrion looks to improve charging speed of high energy density lithium ion cells through the development of innovative fabrication strategies. She was made full Professor in 2019.
In 2021, Wood was made the Vice President for Knowledge Transfer and Corporate Relations at ETH Zurich. She was appointed Meeting Chair of the Materials Research Society 2022 Spring Meeting.
Awards and honors
2014 BASF Science Prize in Electrochemistry
2018 MRS Outstanding Early-Career Investigator Award
Selected publications
References
1983 births
Living people
Yale College alumni
Massachusetts Institute of Technology alumni
American engineers
American women scientists
Academic staff of ETH Zurich
Materials scientists and engineers | Vanessa Wood | [
"Materials_science",
"Engineering"
] | 424 | [
"Materials scientists and engineers",
"Materials science"
] |
70,735,451 | https://en.wikipedia.org/wiki/Neohygrocybe%20nitrata | Neohygrocybe nitrata is a species of agaric (gilled mushroom) in the family Hygrophoraceae. It has been given the recommended English name of nitrous waxcap, based on its smell. The species has a European distribution, occurring mainly in agriculturally unimproved grassland. Threats to its habitat have resulted in the species being assessed as globally "vulnerable" on the IUCN Red List of Threatened Species.
Taxonomy
The species was first described in 1801 by mycologist Christiaan Hendrik Persoon as Agaricus nitratus. Czech mycologist Josef Herink transferred it to the genus Neohygrocybe in 1958, but this combination was not validly published. It was later validly combined by Alexander Kovalenko in 1989.
Recent molecular research, based on cladistic analysis of DNA sequences, has confirmed that Neohygrocybe nitrata is a distinct species but does not belong in Hygrocybe sensu stricto.
Description
Basidiocarps are agaricoid, up to 60 mm (5 in) tall, the cap convex to flat, up to 70 mm (3 in) across. The cap surface is smooth, dry, sometimes breaking up into scales when old, grey-brown. The lamellae (gills) are waxy, pale grey to buff with whiter margins. The stipe (stem) is smooth, pale grey to buff, lacking a ring. The spore print is white, the spores (under a microscope) smooth, inamyloid, ellipsoid, measuring about 8 to 9 by 4.5 to 5.5 μm. Basidiocarps have a distinctly nitrous smell.
Similar species
Neohygrocybe pseudoingrata, recently described from the Czech Republic and Slovakia, has a similar nitrous smell, but basidiocarps are typically larger and paler with white stipes. The more widespread European Neohygrocybe ingrata has a context that stains reddish.
Distribution and habitat
The Nitrous Waxcap is widespread but generally rare throughout Europe. Like other waxcaps, it occurs in old, agriculturally unimproved, short-sward grassland (pastures and lawns).
Recent research suggests waxcaps are neither mycorrhizal nor saprotrophic but may be associated with mosses.
Conservation
Neohygrocybe nitrata is typical of waxcap grasslands, a declining habitat due to changing agricultural practices. As a result, the species is of global conservation concern and is listed as "vulnerable" on the IUCN Red List of Threatened Species. Neohygrocybe nitrata also appears on the official or provisional national red lists of threatened fungi in several European countries, including Croatia, Czech Republic, Denmark, Germany, and Norway.
See also
List of Hygrocybe species
List of fungi by conservation status
References
Fungi of Europe
Fungi described in 1801
Hygrophoraceae
Taxa named by Christiaan Hendrik Persoon
Fungus species | Neohygrocybe nitrata | [
"Biology"
] | 635 | [
"Fungi",
"Fungus species"
] |
70,735,498 | https://en.wikipedia.org/wiki/Computer%20Applications%20and%20Quantitative%20Methods%20in%20Archaeology | Computer Applications and Quantitative Methods in Archaeology (CAA) is a global organization bringing together archaeologists, mathematicians and computer scientists. Its aims are to encourage communication between these disciplines, to provide a survey of present work in the field, and to stimulate discussion and future progress. CAA International has been organizing the annual meetings of its members since the 1970s. It has grown into a large community of more than 1000 scholars from around the world. Its members created a dozen of National CAA chapters and special interest groups. CAA International publishes annual proceedings and the Journal of Computer Applications in Archaeology (JCAA).
History of CAA International
Computer Applications and Quantitative Methods in Archaeology (CAA) has been created in the 1970s. Initially, it was a small group of archaeologists and mathematicians interested in computer applications and working in the United Kingdom (UK). The first conference was organized in 1973 in Birmingham, England. In 1992 the first, CAA conference was held outside the UK. Gradually, the CAA has grown into a large international community.
Over the years national chapters have been established. Some having their own workshops series. One of the oldest chapters is in Germany
founded in 1981. CAA Germany has annual meetings since 2010 including joint chapter meetings with Netherlands and Flanders. Germany also hosted the international conference in 2018.
Journal of Computer Applications in Archaeology
The Journal of Computer Applications in Archaeology is the peer-reviewed and open-access academic journal published by CAA. It was established in 2017 and is published online as a continuous volume and issue throughout the year. The current managing editors are Cesar Gonzalez-Perez and Philip Verhagen.
The journal publishes special collections with thematic or regional focus. Past collections include:
Computer applications and quantitative methods in Australasian archaeology
Spatial Computation in Archaeology and History
Fighting illicit trade in antiquities with digital technology
Reflections on Archaeological Lidar
Digital Scholarship in Archaeology
A Bridge too Far - Historical, Archaeological and Criminal Network Research
National Chapters
Over the years national and regional chapters have been established. Some having their own workshops series. One of the oldest chapters is in Germany
founded in 1981. CAA Germany has annual meetings since 2010 including joint chapter meetings with Netherlands and Flanders.
Current active national and regional chapters are:
CAA Australasia (Australia, New Zealand and the Pacific)
CAA Brazil
CAA Czechia/Slovakia
CAA Denmark
CAA France
CAA Germany
CAA Greece
CAA Hungary
CAA India
CAA Netherlands-Flanders
CAA Mexico
CAA North America (USA and Canada)
CAA Norway
CAA Poland
CAA Sweden
CAA Switzerland
CAA United Kingdom
Current CAA International conference
The current 52st CAA International conference is CAA 2025 Athens 'Digital Horizons: Embracing Heritage in an Evolving World'
Previous conferences
The 51th - CAA 2024: 'Auckland Across The Horizon', Auckland, New Zealand
The 50th - CAA 2023: '50 years of synergy', Amsterdam, Netherland
The 49th - CAA 2022: ‘iNside Formation’, Oxford, United Kingdom
The 48th - CAA 2021: ‘Digital Crossroads’, Virtual Conference from Limassol, Cyprus
The 48th - CAA 2020: Oxford, UK (Postponed to 2022 due to COVID-19 pandemic)
The 47th - CAA 2019: ‘Check Object Integrity’, Kraków, Poland
The 46th - CAA 2018: ‘Human History and Digital Future’, Tübingen, Germany
The 45th - CAA 2017: ‘Digital Archaeologies, Material Worlds (Past and Present)’, Atlanta, Georgia, United States
The 44th - CAA 2016: ‘Exploring Oceans of Data’, Oslo, Norway
The 43rd - CAA 2015: ‘Keep the Revolution Going’, Siena, Italy
The 42nd - CAA 2014: '21st Century Archaeology', Paris, France
The 41st - CAA 2013: 'Across Space and Time', Perth, Australia
The 40th - CAA 2012: Southampton, United Kingdom
Next conference
The 52st - CAA 2025: Athens, Greece
References
Computer science conferences | Computer Applications and Quantitative Methods in Archaeology | [
"Technology"
] | 812 | [
"Computer science",
"Computer science conferences"
] |
70,735,874 | https://en.wikipedia.org/wiki/Palynodinium | Palynodinium is an extinct genus of organic-walled dinoflagellate cyst (or dinocyst). It is a fossil species of dinoflagellate cyst used to demarcate the K/Pg boundary, which marks the terminal Cretaceous and the extinction of the dinosaurs. Palynodinium grallator was among the microfossils which lead to the recent discovery of the K/Pg event record in marine sediments of the northeast Pacific.
Dinoflagellate cysts are estimated to be produced by 10–16% of living dinoflagellates as a dormant, zygotic stage of their life cycle, which can accumulate in marine sediments as microfossils. Organic-walled dinoflagellate cysts are noted for their resistance to degradation owing to their composition of dinosporin, a biopolymer similar to sporopolinin characteristic of many terrestrial palynomorphs. Their abundance, cosmopolitan distribution, and quality of preservation in the fossil record since the Middle Triassic make dinoflagellate cysts excellent indicators of primary productivity as well as tools for biostratigraphy and paleoenvironmental reconstructions. The scope of dinoflagellate cyst applications has resulted in ongoing collaborative efforts between industry and academia to refine their taxonomic classification and enhance their utility through database organization.
References
Dinoflagellates
Dinoflagellate biology
Endosymbiotic events
Cretaceous–Paleogene boundary
Cretaceous geology
Events that forced the climate
Extinction events
Paleogene geology
Palynology | Palynodinium | [
"Biology"
] | 321 | [
"Evolution of the biosphere",
"Symbiosis",
"Algae",
"Endosymbiotic events",
"Dinoflagellates",
"Extinction events"
] |
76,561,404 | https://en.wikipedia.org/wiki/Intertidal%20biofilm | An intertidal bioflim is a biofilm that forms on the intertidal region of bodies of water. Bacteria and various microorganisms, including algae and fungi, form communities of adhered cells called biofilms. A matrix of extracellular polymeric substances (EPS) within the biofilm forms sticky coatings on individual sediment particles and detrital surfaces. This feature protects bacteria against environmental stresses like temperature and pH fluctuations, UV exposure, changes in salinity, depletion of nutrients, antimicrobial agents, desiccation, and predation. Particularly, in the ever-changing environments of intertidal systems, biofilms can facilitate a range of microbial processes and create protective microenvironments where cells communicate with each other and regulate further biofilm formation via Quorum Sensing (QS)., While biofilm formation is advantageous to bacteria and other microorganisms involved, the attachment of microorganisms to ship hulls can increase fuel consumption and emission of greenhouse gases, as well as introduce Non-Indigenous Species (NIS), potentially resulting in harmful economic and ecological impacts on the receiving ecosystems.
Formation and development
Biofilm formation
Biofilm formation begins with the initial attachment of microorganisms to a substrate, such as rocks, shells, or sand in the intertidal zone. This process occurs during the reversible attachment phase, in which the microorganisms only lightly adhere to the substrate. In this phase, the bacteria are encompassed in small amounts of EPS; they are still capable of individual movement and may return to planktonic life., Microorganisms may attach to the surface of substrates by weak Van der Waals forces and hydrophobic effects. A study of Pseudomonas aeruginosa mutants showed that twitching motility by type IV pili contributes to the organism’s ability to aggregate on substrates. Another mechanism by which bacteria may adhere to surfaces is the binary division of attached cells. Similar to colony formation on agar plates, as cells divide, the daughter cells spread expansively, forming cell clusters. In all cases, adhesion depends on the microorganisms involved, the nature of the substrate, and the chemical and biological conditions of the environment.
The next stage is the irreversible attachment stage, in which microbes start producing EPS. This process creates a three-dimensional polymer network that acts as the biofilm matrix and encloses the bacteria. In this stage, EPS prevent bacterial cells from moving, keeping them in long-term close contact and allowing interactions such as cell-to-cell communication and horizontal gene transfer to occur. In most biofilms, the microbes constitute less than 10% of the dry mass, while the EPS matrix can comprise over 90%.
Biofilm development
Maturation
Following the irreversible phase, the next phase of the biofilm life cycle is maturation. In this stage, EPS play a critical role in protecting the biofilm from environmental fluctuations such as oxidative damage, antimicrobials, and host immune system response. Microcolonies are formed as a result of the aggregation of microbial cells and the increase of microbes with accessible nutrients. With the increase in cells, the biofilm matures and develops into a “tower” or “mushroom” like structure with a complex architecture of fluid-filled channels and pores.,,
Detachment
Detachment, also known as dispersal, is the final stage of the biofilm life cycle. In this stage, cells are released from the biofilm matrix, individually or in clusters, and either resume planktonic life or attach to another surface., Various factors can lead to cell detachment, including insufficient nutrients, competition, lack of oxygen, and environmental factors.
Features
Taxonomic diversity
Marine biofilm communities have rich and diverse taxa, with Cyanobacteria and Proteobacteria being the dominant phyla. Actinobacteria, Bacteroidetes, and Planctomycetes are also considered to be dominant phyla but their relative abundances differ between locations. Site-specific differences also arise within intertidal biofilms. For instance, intertidal biofilms in Río de la Plata contained high amounts of Betaproteobacteria from the Thauera genus, whereas intertidal biofilms along the Pearl River Estuary contained Alphaproteobacteria and Gammaproteobacteria as the most prominent taxa.
Extracellular Polymeric Substances (EPS)
Diatoms are a major component of intertidal biofilms, and they excrete EPS that support many functions, such as desiccation resistance, motility, and metabolite exchange. The EPS produced by microalgae also enhance biofilm growth and help other members of the biofilm with adhesion and migration. EPS are mostly composed of polysaccharides, but may also include proteins, nucleic acids, lipids, and low-molecular-weight, non-carbohydrate compounds.
Seasonal variation
Intertidal biofilms exhibit stratification, where different microorganisms arrange themselves in layers based on factors like seasonality. Microalgae are found on the lower shore but their distribution can change. During the winter, a greater abundance and biomass of microalgae are found on the upper shore compared to the lower shore. Seasonal variability is also observed in the relative abundance of microalgae in intertidal biofilms. Specifically, microalgae in tropical and temperate intertidal biofilms are most abundant during winter and spring, with abundance decreasing in the warmer months. Cyanobacteria are relatively less affected by seasonal variation. This may be attributed to their greater tolerance to stressors such as temperature and insolation.
Interactions within the biofilm
Interactions within biofilms are bidirectional. They can be affected by negative and positive feedback loops, as well as indirect effects. These interactions contribute to the resilience and adaptability of intertidal biofilms.
Trophic interactions
Within intertidal biofilms, trophic interactions exist between microphytobenthos and bacteria. EPS, which are produced by microphytobenthos, act as a trophic resource, but their large size makes them difficult to break down and assimilate. Bacteria secrete various enzymes like β-glucosidase to break down complex carbohydrate compounds in EPS. These carbohydrates serve as a nutrient source for heterotrophic bacteria and sulfate-reducing bacteria (SRB), as well as a carbon source for consumers such as marine invertebrates.
Quorum Sensing (QS)
Biofilm communities facilitate both intra-species communication and inter-species communication through QS, which relies on the production and release of signaling molecules known as autoinducers. When autoinducers reach a specific threshold concentration, signaling pathways are activated, resulting in physiological changes. QS, alongside other methods of cell signaling regulation, is important for intertidal biofilms, as it allows them to survive in fluctuating environments and varying conditions. This is because the expression of many genes in biofilms is shown to be density-dependent, with QS playing a crucial role in modulating feedback loops. Autoinducer signals have also resulted in biofilms having a very different architecture compared to those with no QS capabilities.
Adaptations to varying conditions
Intertidal biofilms exhibit diverse adaptation mechanisms to cope with fluctuating conditions such as light stress, metal ion and oxidative stress, and desiccation stress.
Light stress
As intertidal biofilms are found in locations with fluctuating environmental conditions, biofilm microalgae are often damaged by the accumulation of reactive oxygen species (ROS). High levels of ROS induce photoinhibition, inactivating the photosystem II protein D1 and negatively affecting primary productivity. In these conditions, estuarine diatoms improve the efficiency of the xanthophyll cycle, limiting the amount of photodamage and providing the biofilm with a photo-protective mechanism. Vertical migration also allows members of the biofilm community to adapt to light stress. Cells migrate toward the sediment surface when a tide leaves, then migrate downwards upon the arrival of an incoming tide.
Metal ion and oxidative stress
Industrial activities in intertidal regions lead to increased concentrations of heavy metals such as copper, zinc, and cadmium, resulting in metal ion stress for the biofilms. To adapt to these conditions, genes involved in metal ion transport and secondary metabolism are over-expressed by intertidal microorganisms, allowing them to transport the heavy metals against electrochemical gradients and prevent toxicity. The expression of EPS is also enhanced when exposed to increased levels of heavy metals. EPS serves as an adaptive mechanism to tolerate metal ion stress as its components have functional groups that bind toxic heavy metals and prevent heavy metal toxicity.
Desiccation stress
Desiccation leads to a significant decrease in the photosynthetic activity of microphytobenthos in biofilms. To slow down desiccation, diatoms and bacteria in the biofilm produce EPS, decreasing the rate of water loss and dehydration. EPS produced from a Microbacterium species have also been identified to have surfactant properties, playing a role in protecting against desiccation. Alternatively, another protection mechanism against desiccation involves vertical migration, the same strategy that microorganisms use to protect against light stress. Motile diatoms migrate downwards when exposed to extreme light and temperature conditions, as this allows them to be present in a moist microenvironment and mitigate the effects on photosynthetic activity.
Ecological impact and functions
The cohesive nature of EPS contributes not only to the sediment's stability, preventing its resuspension under erosion, but also enhances flocculation processes. Flocculation processes involve the accumulation of fine sediments into larger flocs, modifying biogeochemical exchanges. This stabilization is important for geomorphologic evolution and the ecosystem health of coastal areas. A study from Jiangsu coast, China concluded that flocculation processes affect the density, particle size, and settling velocity of suspended particles, which are essential for sedimentation and sediment transport. These processes are also important in biogeochemical cycles for nutrients and heavy metals due to the adsorption ability and transport function of particles in flocs.
Intertidal marine biofilms on rocky substrates significantly impact estuarine carbon and nutrient dynamics. Biofilms in the Douro River estuary were observed to engage actively in biogeochemical processes, showing considerable net primary production that greatly exceeded respiration rates. These biofilms play a key role in nutrient fluxes, consistently removing nitrate and silicate from the water column while exhibiting variable fluxes of ammonium depending on light conditions, indicating a preference for ammonium assimilation by primary producers within the biofilms. Despite their limited spatial coverage, rocky biofilms account for a significant portion of the nitrate and silicate uptake compared to adjacent sandy and muddy sediments within the estuary.
Impacts of anthropogenic activities
Biofouling on marine structures
The attachment and growth of marine organisms on submerged artificial structures, such as ship hulls and aquaculture infrastructures, can cause ecological and economic issues. This biofouling leads to increased drag resistance, fuel consumption, and greenhouse gas emissions for ships. It also restricts water exchange, raises disease risk, and causes deformation in aquaculture setups.
Introduction of Non-Indigenous Species (NIS)
Biofouling on ships, both as hull fouling and through solid ballast (sand, rocks, and soil), is a major pathway for the arrival of NIS into new regions. This introduces significant risks to receiving ecosystems, potentially resulting in significant economic and ecological impacts. Ports, which are primary receivers of maritime trade goods, are particularly at high risk for NIS introductions. Monitoring NIS presence and impacts, while implementing preventive measures to minimize their settlement, are critical for marine environmental management.
Resilience of biofilms on human activities
A research study conducted along the southeast coast of Brazil showed that human activities, such as trampling, were minimal. A trend of increased variability in biofilm biomass was observed with more intense trampling but no significant differences were found across trampling frequencies and intensities. The microorganisms' small size, which prevents complete removal by trampling, and the biofilms' capacity for rapid recovery may contribute to their high resilience to physical disturbance.
References
Bacteriology
Environmental microbiology
Membrane biology
Aquatic ecology
Biological oceanography
Marine microorganisms | Intertidal biofilm | [
"Chemistry",
"Biology",
"Environmental_science"
] | 2,624 | [
"Membrane biology",
"Environmental microbiology",
"Ecosystems",
"Molecular biology",
"Aquatic ecology",
"Marine microorganisms",
"Microorganisms"
] |
76,561,571 | https://en.wikipedia.org/wiki/Entoloma%20conferendum | Entoloma conferendum is a species of agaric (gilled mushroom) in the family Entolomataceae. In the UK it has been given the recommended English name of Star Pinkgill, based on its distinctive basidiospores. The species is widespread throughout Europe, occurring mainly in agriculturally unimproved grassland, and has also been reported from North America.
Taxonomy
The species was first described by German mycologist Max Britzelmayr in 1881 as Agaricus conferendus. Italian mycologist Pier Andrea Saccardo transferred it to the genus Nolanea in 1887 and, when Nolanea was synonymized with Entoloma, Dutch mycologist Machiel Noordeloos transferred it to the latter genus in 1980. For many years the species was known as Nolanea staurospora, now considered a later synonym.
Description
Basidiocarps are agaricoid, up to 80 mm (3 in) tall, the cap conical becoming convex with age, up to 60 mm (2.5 in) across. The cap surface is smooth, striate at margins when moist, grey-brown to ochraceous brown. The lamellae (gills) are white becoming pink from the spores. The stipe (stem) is smooth, slender, and conspicuously silvery striate, the striations often slightly twisted, lacking a ring. The spore print is pink, the spores (under a microscope) multi-angled and stellate, inamyloid, measuring about 7.5 to 13 μm across.
Distribution and habitat
The Star Pinkgill is common and widespread in Europe. Like many other European pinkgills, it typically occurs in old, agriculturally unimproved, short-sward grassland (pastures and lawns), but may sometimes occur in woodland and bogs. The species has also been reported from North America.
References
Entolomataceae
Fungi of Europe
Fungi of North America
Fungi described in 1881
Fungus species | Entoloma conferendum | [
"Biology"
] | 417 | [
"Fungi",
"Fungus species"
] |
76,562,844 | https://en.wikipedia.org/wiki/Manganese%28II%29%20perchlorate | Manganese(II) perchlorate is an inorganic chemical compound with the formula Mn(ClO4)2. It forms a white-colored anhydrous and a rose-colored hexahydrate, both of which are hygroscopic. As a perchlorate, it is a strong oxidizing agent.
Production and reactions
The hexahydrate can be produced by reacting manganese metal or manganese(II) carbonate with perchloric acid, followed by the evaporation of the solution. The hexahydrate does not dehydrate when heating but instead oxidizes to manganese dioxide at 150 °C.
To produce the anhydrous form, manganese(II) nitrate is reacted with dichlorine hexoxide at 5 °C:
Mn(NO3)2 + 4 Cl2O6 → NO2Mn(ClO4)3 + NO2ClO4 + 4 ClO2 + O2
The resulting nitryl salt is subsequently heated at 105 °C in a vacuum to produce the anhydrous perchlorate.
NO2Mn(ClO4)3 → Mn(ClO4)2 + NO2ClO4
Structure
The anhydrous form is predicted to be isostructural with cobalt(II) perchlorate, based on the IR spectrum and the Raman spectrum of the compound.
The hexahydrate consists of discreet [Mn(H2O)6]2+ octahedrons and perchlorate anions with lattice constants a = 7.85 Å, b = 13.60 Å and c = 5.30 Å. The hexahydrate undergoes phase transitions at low temperatures.
References
Manganese(II) compounds
Perchlorates | Manganese(II) perchlorate | [
"Chemistry"
] | 372 | [
"Perchlorates",
"Salts"
] |
76,563,227 | https://en.wikipedia.org/wiki/Tsong%20Yueh%20Chen | Tsong Yueh Chen () is an Australian academic at the Swinburne University of Technology who is a professor and researcher in program testing and debugging. He is ranked internationally as the most prolific author in metamorphic testing.
Chen received the BSc and MPhil from The University of Hong Kong, the MSc and DIC from Imperial College London, and the PhD from The University of Melbourne under the supervision of Jean-Louis Lassez. He has an h-index of 62.
In 2021, Chen et al. were selected as the Grand Champion of the Most Influential Paper Award by the Journal of Systems and Software for their 2010 paper.
In January 2024, Chen was selected for the ACM SIGSOFT Outstanding Research Award 2024 “for contributions to software testing through the invention and development of metamorphic testing”. This award is presented to individual(s) who have made significant and lasting research contributions to the theory or practice of software engineering. As tokens of recognition, Chen was invited to give a keynote speech at the International Conference on Software Engineering in April 2024, and was interviewed by ACM SIGSOFT Software Engineering Notes after his presentation.
In December 2024, IEEE announced the election of Tsong Yueh Chen as an IEEE Fellow in the class of 2025 “for contributions to software testing through the invention of metamorphic testing and adaptive random testing”. Only three software engineers were elected as IEEE Fellows in the same year.
Selected publications
.
References
External links
Swinburne University of Technology biography
Year of birth missing (living people)
Living people
Computer scientists
Software engineering researchers
Software testing people
Alumni of Imperial College London
Academic staff of Swinburne University of Technology | Tsong Yueh Chen | [
"Technology"
] | 342 | [
"Computer science",
"Computer scientists"
] |
76,564,180 | https://en.wikipedia.org/wiki/Sulfurospirillum | Sulfurospirillum (/ˌsʌlfɜːroʊspɪˈrɪlʌm/ SULF-ur-oh-spə-RIHL-um) is a genus of the gram-negative, aerotolerant, rod-shaped bacteria in the family Campylobactaeraceae.
Details
Many species are microaerophillic, and are thus found in soil, groundwater, the deep sea, marine surface sediments, tube worm guts, and polluted environments. Many species can grow on toxic compounds such as arsenate and selenate, and in fact flourish in contaminated sites. The Sulfurospirillum genus contains the only species on the planet that can respire organohalides. No species in the Sulfurospirillum genus have been found to be pathogenic thus far.
References
Bacteria genera
Campylobacterota
Environmental microbiology | Sulfurospirillum | [
"Environmental_science"
] | 169 | [
"Environmental microbiology"
] |
76,564,427 | https://en.wikipedia.org/wiki/Artificial%20saliva | Artificial saliva or salivary substitutes refer to a synthetically produced liquid that mimics the natural secretion of saliva. It is designed as a symptomatic relief for xerostomia, a condition characterised by dryness in the mouth and is available over-the-counter. The efficacy of artificial saliva in a systematic review of clinical trials indicates that all evaluated products reduce xerostomia symptoms, but the comparative effectiveness remains unclear due to study inconsistencies and potential biases. Side effects are uncommon, but users should take precautions against possible side effects such as allergic reactions.
Artificial saliva is mainly composed of bioactive compounds, which substitute for natural saliva's biological functions, such as facilitating antimicrobial activity, digestion and lubrication of oral tissues. Additional components such as buffering and flavouring agents are added to increase the stability of formulations and user acceptance, respectively. These formulations are available in various forms and have varied chemical-physical properties.
Current research on artificial saliva focuses on expanding its functionality by incorporating synthetic molecules similar to their biological counterparts in natural saliva. The study includes efforts to enhance native salivary proteins and synthesise novel molecules using various chemical and genetic engineering techniques.
Clinical applications
Artificial saliva is primarily used to relieve symptoms of xerostomia, known as dry mouth and hyposalivation, which is a condition that results in reduced saliva production. Various factors, including medication use, cancer therapy, and certain diseases, such as diabetes, stroke or Sjögren syndrome, can cause xerostomia. Artificial saliva supplements any pre-existing saliva in individuals with xerostomia, and its primary function is to restore moisture in the oral cavity. Artificial saliva is available over-the-counter and comes in various formulations, including gels, mouth rinses and sprays.
Artificial saliva also contributes to oral health maintenance by promoting enamel defence against acidic erosion. In individuals with a high intake of soft drinks or a high vomiting frequency and a decrease in saliva flow, artificial saliva can help improve the clearance time of acids and reduce the chance of dental erosion.
Efficacy
The assessment of artificial saliva's efficacy reveals a consensus that all evaluated products contribute to reducing xerostomia symptoms in a systematic review of clinical trials. The review indicated that herbal products are better than artificial saliva in alleviating symptoms of radiation-induced xerostomia, while oral spray presentation and saliva substitutes containing 3% citric acid provide longer-lasting relief for drug-induced xerostomia. The selection and combination of saliva substitutes should be tailored to the individual's needs, preferences and oral health status. Despite the variety of products tested, a definitive judgment on their comparative effectiveness is challenging due to the heterogeneity of the studies in terms of the products, sites and durations involved and many studies exhibit a high risk of bias.
Side effects
Side effects of artificial saliva are relatively uncommon but still exist with varying severity. Minor side effects might not necessitate medical attention. However, in certain instances, users may experience symptoms indicative of an allergic reaction, such as rash, hives, itching, and swelling in the mouth, face, lips, tongue or throat and should consult a doctor. Common side effects include:
Speech disturbance
Distortion in taste (dysgeusia)
Difficulty in swallowing (dysphagia)
Minor gastrointestinal problems
Warnings
Individuals with fructose intolerance should be aware that certain artificial saliva products contain fructose and should be avoided. Users adhering to a sodium-restricted diet must exercise caution when selecting an artificial saliva product, as some, including Caphosol, may contain considerable amounts of sodium.
Composition
Artificial saliva comprises an array of bioactive compounds designed to mimic the natural functions of human saliva to alleviate symptoms of dry mouth by aiding in speaking and swallowing, and it provides general comfort by simulating the sticky consistency of natural saliva. The composition typically includes cellulose derivatives, buffering and flavouring agents as core components, ensuring the product's efficacy and palatability.
Cellulose derivatives
Cellulose derivatives are rheological modifiers, which are compounds responsible for the viscosity and texture of artificial saliva, enabling it to adhere to oral tissues and provide a protective and lubricating film. The viscosity of cellulose derivatives is greater than that of natural human saliva. Cellulose derivatives include:
Carboxymethyl cellulose
Hydroxyethyl cellulose
Hydroxypropyl methylcellulose
Mucin
Mucin is a glycoprotein prevalent in natural saliva, and lab-made mucin can closely replicate the characteristics of natural saliva by forming a protective and lubricative film on oral surfaces. Mucin has an elevated adsorption capacity compared to carboxymethyl cellulose-based formulations, which improves lubrication. Clinical trials have indicated a preference among users for saliva substitutes containing mucin compared to those formulated with carboxymethyl cellulose.
Glycerol
Glycerol is a colourless and odourless lipid and can coat oral surfaces. It aids in humidifying and lubricating the oral cavity, easing discomfort associated with dry mouth conditions. Glycerol is a Newtonian fluid with a higher viscosity than natural human saliva.
Enzymes
Enzymes in artificial saliva mimic natural saliva's antimicrobial and digestive functions by contributing to the breakdown of food particles and inhibiting the growth of harmful bacteria, which improves oral health and assists in the digestive process. Enzymes include:
Lysozyme
Lactoferrin
Peroxidase
Minerals
Minerals contribute to dental integrity and serve a protective function in the oral environment. The minerals aid in the remineralisation process, which repairs tooth enamel that might have been demineralised due to various oral conditions or acidic environments. For example, fluoride forms fluorapatite, a compound more resistant to decay than the original hydroxyapatite of the tooth enamel. Minerals include:
Calcium
Phosphate
Fluoride
Buffering agents
Buffering agents in artificial saliva maintain the pH levels, ensuring the oral environment remains within the optimal range for enamel protection and microbial balance. A stable pH prevents tooth decay and maintains oral health. These buffering agents neutralise acidic substances in the oral cavity, safeguarding tooth enamel and soft tissues from acid-related damage. Buffering agents include:
Sodium phosphate
Potassium phosphate
Flavouring agents
Flavouring agents enhance the taste and acceptability of artificial saliva. These agents can mask any unpleasant flavours inherent in the other components and make the user's experience of using artificial saliva more pleasant. Flavouring agents encourage the user's compliance with the treatment regimen, mainly when long-term use is necessary. Flavouring agents include:
Xylitol
Sorbitol
Citric acid
Types
Artificial saliva is available in different types and varies in chemical-physical properties, including viscosity, pH, buffering capacity, superficial tension, density and spinnbarkeit. Types of artificial saliva include:
Oral liquid
Oral spray
Lozenge
Gel
Oil
Mouthwash
Toothpaste
Research
Research on artificial saliva focuses on replicating the biological components of natural saliva to substitute and enhance essential functions such as aiding digestion, performing antimicrobial action and protecting tissue layers. Approaches include enhancing or mimicking salivary proteins in natural saliva.
Enhancing salivary proteins
Salivary proteins such as histatin, statherin and mucin, which possess antimicrobial, lubrication and biomineralisation properties, are targets of enhancement in artificial saliva research as they are significant in maintaining oral health.
Genetic engineering and recombinant DNA techniques produce recombinant salivary proteins for enhanced biological functions. Identification of recombinant histatin and statherin strains is more prevalent as they are smaller and simpler in structure. Therefore, a range of histatin and statherin variants with duplication of active protein domain or removal of phosphorylated serine that enhances antimicrobial activities and enamel biomineralisation were developed and produced.
Recombinant mucins were less widely produced previously due to challenges imposed by the repetitive nature of their DNA sequences, which often results in highly truncated, suboptimal protein production. Substantial research was devoted to developing custom gene synthesis methods to overcome these challenges. The methods were guided by codon scrambling algorithms to reduce repetition in DNA sequences while conserving important information for recombinant protein synthesis.
The downstream genetic expression system of recombinant salivary proteins is also a key area of research, as it affects glycosylation patterns that contribute to their stability and lubrication properties. Efficient modification of glycosylation genes in host cells through genetic engineering techniques like CRISPR/Cas9 to produce salivary proteins with specific glycan phenotypes, which enhance the stability of artificial saliva.
Synthesising novel molecules
Synthesising novel molecules that mimic natural salivary proteins' complete or partial structure is a key aspect of artificial saliva research.
Fully synthesised molecules from a chemical engineering approach include mirror-image mucins and thio-mucins, produced from monomers incorporated with enantiomer amino acids and modified glycan linkages, respectively. These structural analogs have tunable biodegradation rates while maintaining their ability to bind with salivary proteins, thus improving artificial saliva's stability and lubrication properties.
Another class of novel molecules developed from a genetic engineering approach to mimic salivary proteins are recombinant supercharged polypeptides (SUPs). They are produced from the construction of new DNA sequences that express SUPs consisting of repetitive units encoding for glycine (G), valine (V), proline (P), and lysine (K) amino acids. This polypeptide class has increased interaction with the layering of salivary conditioning films (SCFs) coating oral tissues, which helps improve oral lubrication.
Novel molecules developed to mimic partial structures of salivary proteins include chemically modified O-glycans, using methods such as direct oxidation and metabolic glycoengineering. The modified O-glycans facilitate mucin conjugation with other molecules in the oral cavity for enhanced physical properties and bioactivity.
References
Saliva
Synthetic biology | Artificial saliva | [
"Engineering",
"Biology"
] | 2,118 | [
"Synthetic biology",
"Biological engineering",
"Saliva",
"Excretion",
"Bioinformatics",
"Molecular genetics"
] |
76,564,936 | https://en.wikipedia.org/wiki/NGC%201253 | NGC 1253 is a spiral galaxy in the constellation Eridanus. The galaxy lies about 70 million light years away from Earth, which means, given its apparent dimensions, that NGC 1253 is approximately 110,000 light years across. It was discovered by William Herschel on September 20, 1784.
NGC 1253 is categorised as having a having a bar, however its spiral arms are similar to that of Whirlpool Galaxy. The galaxy has two spiral arms, probably as a result of interaction with its satellite. The spiral arms end in what looks like a ring of hydrogen gas, while the inner area of the galaxy appears to be hydrogen poor. The velocity pattern indicates that the ring lies at the outer Lindblad resonance. The highest hydrogen density is observed at the northwest part of the ring. The largest HII regions of the galaxy lie along that ring. The supermassive black hole located in the centre of the galaxy is estimated to have a mass of 106.99 ± 0.53 (3 − 33 millions) .
NGC 1253 forms an interacting pair with NGC 1253A, a Magellanic spiral galaxy which lies 3.7 arcminutes away, which corresponds to a projected distance of 25 kiloparsecs. The two galaxies share a common hydrogen envelope. The hydrogen envelope has an extension at its eastern side to the north that could be a tidal tail. The two galaxies belong in the same galaxy cloud as Messier 77 and its group.
References
External links
Intermediate spiral galaxies
Interacting galaxies
Eridanus (constellation)
1253
062
279
-01-09-018
12041
Discoveries by William Herschel
Astronomical objects discovered in 1784 | NGC 1253 | [
"Astronomy"
] | 341 | [
"Eridanus (constellation)",
"Constellations"
] |
76,565,447 | https://en.wikipedia.org/wiki/Kisan%20Ghat | Kisan Ghat (transl. Farmer’s memorial) is a historical landmark at Raj Ghat, New Delhi, marking the cremation site of Chaudhary Charan Singh, the fifth prime minister of India, who was a prominent farmer leader known for his advocacy for the agricultural community. His birth date, 23 December, is celebrated as Kisan Diwas in India.
Description
Kisan Ghat is built in a simple design to denote the humble origins of Charan Singh. The memorial is built in a square shape using marble. The memorial is surrounded by thick shrubs on all sides that make it impressive. Ironically, according to most historians, Chaudhary Charan Singh's memorial is located close to the memorial of Congress leaders whom he opposed.
Historical significance
Charan Singh served as the prime minister of India from July 1979 to January 1980. His policies and advocacy played an important role in shaping India's agricultural landscape.
References
Monuments and memorials in Delhi
Memorials to Chaudhary Charan Singh
Cremation | Kisan Ghat | [
"Chemistry"
] | 211 | [
"Cremation",
"Incineration"
] |
76,565,600 | https://en.wikipedia.org/wiki/Microscopical%20researches%20into%20the%20accordance%20in%20the%20structure%20and%20growth%20of%20animals%20and%20plants | Microscopical researches into the accordance in the structure and growth of animals and plants is a famous treatise by Theodor Schwann published in 1839 which officially formulated the basis of the cell theory. The original title was Mikroskopische Untersuchungen über die Uebereinstimmung in der Struktur und dem Wachsthum der Thiere und Pflanzen. The book has been called "a conspicuous milestone in nineteenth century biology" by Karl Sudhoff and "epoch making" By Francis Münzer.
The book, originally published in German, was translated to English in 1847 by Henry Spencer Smith in an edition that also contained the treatise Phytogenesis, by Matthias Schleiden.
Besides the theoretical work, that Schwann called a "philosophical" section of general anatomy, Schwann provided several plates with drawings of cells and tissues and discussions of observations of other microscopists.
Cell theory
Schwann dedicated a chapter of the treatise to explicitly formulate the cell theory, stating that ("the elementary parts of all tissues are formed of cells” and that “there is one universal principle of development for the elementary parts of organisms... and this principle is in the formation of cells" (Henry Smith's translation, 1847). His book had the goal to prove via observations that the cell theory put forth for plants by Matthias Schleiden was equally valid for animals.
Schwann cell
The book is credited with the first description of what would later be called Schwann cell, a type of glial cell. The description of the cells was evident from passages such as:
and
Metabolism
The book is also credited with the introduction of the term "metabolism" for the following quote in the chapter "Theory of Cells":
References
Cell biology
Biology books
1839 in science | Microscopical researches into the accordance in the structure and growth of animals and plants | [
"Biology"
] | 373 | [
"Cell biology"
] |
76,566,332 | https://en.wikipedia.org/wiki/Lak%C3%A1skult%C3%BAra | Lakáskultúra (, ) is a monthly interior design magazine which has been in circulation since 1964. The magazine is headquartered in Budapest, Hungary.
History and profile
Lakáskultúra was established by the Hungarian Architects’ Association in Budapest in 1964. The Association was also one of the sponsors of the magazine. Its publication became regular from 1967. The magazine was part of the Ministry of Domestic Trade between 1964 and 1987. Then it was owned by Pallas until 1989 when Axel Springer Budapest KFT acquired it. The magazine appears monthly.
During the Communist era Lakáskultúra contributed to the state ideology of socialist consumer. It was one of the most read and significant publications in this period. Its popularity was partly because of its content on distinct interior furnishings, room arrangements, decorative inclinations and homes of Hungarian families. Therefore, it hardly ever featured accessories exhibited in trade shows and fairs and professionally designed interiors. The magazine has also published apartment layouts and floor plans.
References
External links
1964 establishments in Hungary
Communist magazines
Hungarian-language magazines
Design magazines
Former state media
Magazines established in 1964
Magazines published in Budapest
Architecture magazines
Axel Springer SE | Lakáskultúra | [
"Engineering"
] | 229 | [
"Design magazines",
"Design"
] |
76,566,625 | https://en.wikipedia.org/wiki/IC%201623 | IC 1623 is a galaxy merger in the constellation Cetus. The galaxy lies about 250 million light years away from Earth, which means, given its apparent dimensions, that IC 1623 is approximately 115,000 light years across. It was discovered by Lewis Swift on November 19, 1897.
Characteristics
IC 1623 consists of two galaxies in the early to mid stages of merger. The nuclei of the two galaxies lie 20 arcseconds apart. The western component (VV 114W) is bright in ultraviolet and optical light and hosts a large number of optically luminous young star clusters. The eastern component, VV 114E, is invisible at UV wavelengths and has prominent dust lanes that cover much of the diffuse light of the underlying stellar population at optical wavelengths. Beyond 1 μm, VV 114E increasingly becomes the dominant luminosity component of the merger, being the brightest source in mid infrared. The whole galaxy shines bright in infrared and it is characterised as a luminous infrared galaxy, with a total infrared luminosity (LIR) of 5 × 1011 L⊙.
The James Webb Space Telescope (JWST) observed the nucleus of the eastern galaxy in mid-infrared, revealing a northeastern and a southwestern core. The mid-infrared colors of these cores indicate that the northeastern core is associated with a starburst, while the southwestern core is linked to an active galactic nucleus (AGN). Spectral line analysis suggests the presence of a rapidly accreting intermediate-mass black hole in the southwestern nucleus, which may evolve into a supermassive black hole. Additionally, JWST identified 40 star-forming regions with a total star formation rate ranging from 0.02 to 6 solar masses per year. There is also significant diffuse emission from filaments, primarily attributed to polycyclic aromatic hydrocarbons heated by the star-forming regions and the underlying stellar population.
References
External links
Galaxy mergers
Luminous infrared galaxies
Cetus
1623
236
1053-1746
04008
Discoveries by Lewis Swift
Astronomical objects discovered in 1897
541-IG 023 | IC 1623 | [
"Astronomy"
] | 416 | [
"Cetus",
"Constellations"
] |
76,566,723 | https://en.wikipedia.org/wiki/John%20Paul%20%28medical%20scientist%29 | John Paul (25 April 192227 June 1994) was a biomedical research scientist living in Scotland, UK. He was the founding director of the Beatson Institute for Cancer Research in Glasgow, Scotland.
He wrote five books on the subject of cell biology, tissue culture and cancer, including Cell Biology: A Current Summary and Cell and Tissue Culture.
In 1961 he invented and patented an apparatus for cell and tissue culture. In 1966, he, along with Robert Edwards, derived the world’s first embryonic stem cells.
Early life and education
Paul was born on 25 April 1922 in Wishaw, Lanarkshire, Scotland. He graduated from the University of Glasgow with an MB ChB in 1944, then completed a PhD in biochemistry. He was the Ure scholar at Glasgow University in 1948–51 and the McCunn scholar at the University of Edinburgh, followed by a research fellowship (Rockefeller travelling research fellowship) at the Columbia University College of Physicians and Surgeons in New York in 1952–53.
Career
He was director of the Tissue Culture Laboratories of the Department of Biochemistry in the University of Glasgow and became a reader in 1962 and a Titular Professor in 1964. He left Glasgow University in 1966 to become Director of the Cancer Research Laboratories of the Royal Beatson Memorial Hospital in Glasgow.
He retired in 1987 and died 27 June 1994.
Awards and honours
Paul was awarded an honorary DSc by the University of Glasgow in 1989.
There is a John Paul Career Award named after him, which third year PhD students at the Scotland Institute are eligible for.
References
1922 births
1994 deaths
Scottish medical researchers
Alumni of the University of Glasgow
People from Wishaw
20th-century Scottish scientists
20th-century British biologists
Cancer researchers
20th-century Scottish medical doctors
Physician-scientists
Stem cell researchers | John Paul (medical scientist) | [
"Biology"
] | 352 | [
"Stem cell researchers",
"Stem cell research"
] |
76,567,630 | https://en.wikipedia.org/wiki/Gross%20ecosystem%20product | The Gross Ecosystem Product (GEP) is an innovative metric developed to account for the economic value of ecosystem services within broader economic evaluations, traditionally measured by Gross Domestic Product (GDP). While GDP provides a quantitative measure of all goods and services produced economically within a country, it does not consider the ecological services that underpin economic output. GEP addresses this oversight by measuring the contribution of ecosystems through direct products, regulation services such as climate control, and cultural services like tourism.
Overview and application
China introduced a national standard for GEP in 2020, integrating ecological values into its economic assessment framework. This initiative has led to its adoption at several governmental levels. By 2023, 15 local governments in China had developed guidelines to implement GEP, initiating approximately 200 related projects. In Zhejiang, the first province to implement these rules, the performance of local officials is evaluated in part by the economic values assigned to local ecosystems, such as a US$43 million value attributed to the Chengtian Radon Spring Nature Reserve.
GEP is also used in economic modeling to provide a comprehensive view of the interplay between economic and ecological health. For example, the MAGNET model, developed by the Joint Research Centre (JRC) and Wageningen Economic Research, incorporates GEP to analyze how policies can simultaneously affect economic output and ecosystem conditions. This model helps policymakers make informed decisions that strive to harmonize economic development with environmental sustainability.
The ongoing development of GEP aims to improve its precision and practicality in economic and environmental policy-making. By assigning monetary values to ecosystem services, GEP facilitates a deeper understanding of their critical role in sustainable economic development. This approach ensures that strategies for economic growth also support ecological well-being, emphasizing a balanced approach to development.
See also
Ecological economics
Sustainability metrics and indices
Sustainability measurement
Ecological footprint
Environmental accounting
Environmental Performance Index
References
Sustainability metrics and indices
Sustainable development
Environmental social science concepts | Gross ecosystem product | [
"Environmental_science"
] | 384 | [
"Environmental social science concepts",
"Environmental social science"
] |
76,567,874 | https://en.wikipedia.org/wiki/Soyuz%20MS-28 | Soyuz MS-28, Russian production No. 759 and identified by NASA as Soyuz 74S, is a planned Russian crewed Soyuz spaceflight to launch from Site 31/6 at the Baikonur Cosmodrome no earlier than 27 November 2025 to the International Space Station.
The mission is slated to be the first to launch after the termination of a NASA/Roscosmos barter agreement, where one Russian cosmonaut flies on a NASA spacecraft in exchange for one NASA astronaut flying on a Soyuz. Consequently, , this mission is currently scheduled to transport three Russian cosmonauts. However, NASA and Roscosmos are negotiating to extend their seat exchange program beyond 2025.
Crew
References
Crewed Soyuz missions
Future human spaceflights
2025 in spaceflight
2025 in Russia | Soyuz MS-28 | [
"Astronomy"
] | 163 | [
"Outer space stubs",
"Astronomy stubs",
"Outer space"
] |
76,567,957 | https://en.wikipedia.org/wiki/Soyuz%20MS-29 | Soyuz MS-29 is a planned Russian crewed Soyuz spaceflight to launch from Baikonur in March 2026 to the International Space Station.
Crew
References
Crewed Soyuz missions
Future human spaceflights
2026 in spaceflight | Soyuz MS-29 | [
"Astronomy"
] | 47 | [
"Outer space stubs",
"Outer space",
"Astronomy stubs"
] |
76,568,876 | https://en.wikipedia.org/wiki/The%20Hagedorn%20Prize | The Hagedorn Prize is an annual award within the field of medical research, specifically recognizing outstanding contributions to diabetes research and endocrinology. Named after Hans Christian Hagedorn, a renowned Danish scientist and co-founder of Nordisk Insulinlaboratorium (now part of Novo Nordisk), the prize celebrates achievements in the understanding and treatment of diabetes.
Hagedorn's work significantly advanced the quality of insulin production and diabetes care, making this award a tribute to his legacy in the field. The Hagedorn Prize is recognised as the most prestigious award in Internal medicine in Denmark.
Background
History
The Hagedorn Prize was established by the Danish Society of Internal Medicine in 1966 to recognize the contribution to medical science made by Hans Christian Hagedorn (1888–1971). The prize is awarded at the society's annual general meeting.
Initially, the Hagedorn Prize received its endowment from a distinct foundation, funded by contributions from Nordisk Insulinlaboratorium, with the Board of the Danish Society for Internal Medicine serving as its governing body. However, by 2008, the foundation's resources were deemed inadequate to sustain a meaningful award. Consequently, the remaining capital was transferred to the Novo Nordisk Foundation, which subsequently assumed the responsibility of bestowing the Hagedorn Prize, while maintaining the ongoing involvement of the Society. The recipient of the prize is determined by the society's board, relying on recommendations provided by its members.
About the Danish Society of Internal Medicine
The Danish Society of Internal Medicine, comprising nearly 4,500 members, serves as an overarching body for the nine internal medicine specialties within Denmark. Its objectives include the advancement of scientific research in internal medicine and the facilitation of ongoing education for specialist physicians in the discipline. Established in 1916, the Society operates with a board of directors composed of nine members, appointed by the boards of each respective internal medicine specialty.
Award
The Hagedorn Prize includes a monetary component, designed to support the ongoing research of the recipient. In addition, awardees are presented with a medal and a certificate recognizing their contributions to advancing diabetes research and treatment. The prize is intended not only to honor individuals for their past achievements but also to encourage further innovation and research in diabetes care.
Recipients
List of recipients of The Hagedorn Prize
References
Academic awards
Danish science and technology awards
Diabetes research
Medicine awards
Research awards | The Hagedorn Prize | [
"Technology"
] | 479 | [
"Science and technology awards",
"Medicine awards",
"Research awards"
] |
76,571,277 | https://en.wikipedia.org/wiki/Dow%20process%20%28phenol%29 | The Dow process is a method of phenol production through the hydrolysis of chlorobenzene.
Details
Benzene can be easily converted to chlorobenzene by nucleophilic aromatic substitution via a benzyne intermediate. It is treated with aqueous sodium hydroxide at 350 °C and 300 bar or molten sodium hydroxide at 350 °C to convert it to sodium phenoxide, which yields phenol upon acidification.
When 1-[14C]-1-chlorobenzene was subjected to aqueous NaOH at 395 °C, ipso substitution product 1-[14C]-phenol was formed in 54% yield, while cine substitution product 2-[14C]-phenol was formed in 43% yield, indicating that an elimination-addition (benzyne) mechanism is predominant, with perhaps a small amount of product from addition-elimination (SNAr).
References
Chemical processes | Dow process (phenol) | [
"Chemistry"
] | 196 | [
"Chemical process engineering",
"Chemical process stubs",
"Chemical processes",
"nan"
] |
76,571,690 | https://en.wikipedia.org/wiki/DotCode | DotCode is two-dimensional (2D) matrix barcode invented in 2008 by Hand Held Products company to replace outdated Code 128. At this time, it is issued by Association for Automatic Identification and Mobility (AIM) as “ISS DotCode Symbology Specification 4.0”. DotCode consists of sparse black round dots and white spaces on white background. In case of a black background the dots can be white. DotCode was developed to use with high-speed industrial printers where printing accuracy can be low. Because DotCode by the standard does not require complicated elements like continuous lines or special shapes it can be applied with laser engraving or industrial drills.
DotCode can be represented as rectangular array with minimal size of each side 5X dots. Maximal size of DotCode is not limited by the standard (as Code 128 is not limited) but practical limit is recommended as 100x99 which can encode around 730 digits, 366 alphanumeric characters or 304 bytes.
As an extension of Code 128 barcode, DotCode allows more compact encoding of 8-bit data array and Unicode support with Extended Channel Interpretation feature. Additionally, DotCode provides much more data density and Reed–Solomon error correction which allows to restore partially damaged barcode. However, the main DotCode implementation, the same as Code 128, is effective encoding of GS1 data which is used in worldwide shipping and packaging industry.
History and standards
DotCode barcode was invented in 2008 by Dr. Andrew Longacre from Hand Held Products company and standardized in 2009 by AIM as “Bar code symbology specification - DotCode”. In 2019 DotCode was reviewed as “ISS DotCode Symbology Specification 4.0”.
Set of patents is registered, which are related with DotCode encoding and decoding:
United States Patent US20090200386A1 by Hand Held Products Inc "Machine readable 2D symbology printable on demand"
United States Patent US20090200386A1 by Datalogic IP Tech SRL "System and method for extracting bitstream data in two-dimensional optical codes"
Chinese Patent CN113297872A by Fuzhou Symbol Information Technology Co ltd "Dotcode identification method and equipment"
Application
DotCode barcode can be used in the same way as Code 128 or any (2D) matrix barcode. At this time, it is used mostly to encode GS1 data in tobacco, alcoholic and non-alcoholic beverage, pharmaceutical and grocery industries. The main implementation at this time is in tobacco industry.
Main advantages of DotCode are:
Full support and replacement of Code 128 codeset;
Compact encoding of 8-bit data array;
Unicode support with Extended Channel Interpretation feature;
Effective encoding of GS1 data;
Reed–Solomon error correction
Ability to apply the barcode by high-speed industrial printers and other methods like laser engraving.
Barcode design
DotCode represents data in rectangular structure which consists from black round dots and white spaces on white background or white round dots on black background. DotCode does not have finder pattern, like other 2D barcodes and it must be detected with slow blob detection algorithms like Gabor filter or Circle Hough Transform. All data, metadata and error correction codewords are encoded in the same dots array which does not have any visual difference.
Here are some samples of DotCode:
DotCode symbol is constructed from the following elements:
Two mask bits which are represented on diagram as two green points;
Data bits (data and error correction bits) which must be read from up to down (even barcode side) and from left to right (odd barcode side);
Corner points, marked as red on diagram, which can be used as data bits or padding bits (black dots);
Quiet zone at least 3X size of the dots.
The DotCode bits array is represented as:
(Two mask bits: M2, M1)(Data bits)(Corner bits, can be data or padding bits: C1 – C6)
The data codewords in 0 – 112 range are encoded in 5-of-9 binary dot patterns which are encoded from 9 dots where 5 black dots and 4 white spaces. The rest of barcode matrix (rest from division on 9) is padded with black padding bits. The padding bits can be from 0 to 8. The logically DotCode bits array is represented as:
(2 mask bits)(Data codewords 9 bits each)(Padding bits 0 – 8 bits)
DotCode size has the following requirements:
Sum of DotCode width and height must be odd: ;
Minimal size of each side must be 5, maximal is not limited;
It is recommended to use width and height to have at least 6 padding black bits where data bits capacity rest from division on 9 more or equal 6:
Data masking
To minimize DotCode problematic symbols, the data codewords are masked to create others visual sequences. The mask pattern is applied only to data sequence and does not affect error correction codewords. DotCode standard has 4 mask pattern which are codded into 2 bits and placed as the first 2 bits of symbol bits array.
Error correction
DotCode uses Reed–Solomon error correction with prime power of 3 and finite field or . The data codewords is represented with values from 0 to 112 and mask value is counted as leading data codeword from 0 to 3. In this way the data protected array length is (1 + ND). But amount of error correction codewords is calculated only from ND:
,
where ND is data codewords and NC - error correction codewords.
The resulting codewords NW with error correction codewords is:
,
where NW is all encoding codewords: 1 mask codeword + data codewords(ND) + error correction codewords(NC).
Because Reed–Solomon error correction cannot correct amount of codewords which are more than polynomial, if NW happens to exceed 112, the data is split into error correction blocks:
,
where B is block counts.
The data can be split into block in the following way, for each block ‘’’n’’’, for n equals 1 to B:
The error correction data is written after single data block in scrambled mode:
(ND)(NC1_1)(NC2_1)(NC3_1)...(NC1_n)(NC2_m)(NC3_k)
Encoding
DotCode encoding size is not limited by standard, but practical encoding size in 100x99 version which includes 4950 dots can encode 366 raw data codewords, 730 digits, 365 alphanumeric characters, or 304 bytes. The data message in DotCode is represented with data codewords from 0 to 112 which are encoded with 5-of-9 binary dot patterns.
DotCode supports the following features:
Natively encodes digits or ASCII charset (between 0 and 127) with A, B and C code sets and extended ASCII values (128 to 255) with Upper Shift;
Effectively encodes bytes (5 bytes into 6 codewords) with Binary Latch;
Encodes GS1 data;
Encodes Unicode symbols with Extended Channel Interpretation feature;
Supports Structured append encoding (logically using multiple barcode symbols as single data stream);
Supports “Macro” encoding.
There three main rules at message encoding start:
The default starting encoding is Code Set C;
In case of two digits in Code Set C (0 – 100 value) are encoded in the position of the first codeword, the message is decoded as GS1 message;
If FNC1 (opposite effect to Code 128) or other non-digit codeword (101 - 112) is encoded in the position of the first codeword, the message is decoded as NON GS1 message.
Binary byte encoding
DotCode can encode full 8-bit charset in two ways:
With Upper Shift, which requires 2 codewords on one (128 to 255) symbol;
With Binary Latch, which requires 1 Binary Latch symbol and 6 codewords on every 5 bytes.
Upper Shift modes can encode (128 to 255) extended ASCII characters in two codewords with returning to previous mode:
Binary Latch mode can encode 8-bit charset and ECI sequences from 1 to 5 symbols. It uses the following rules:
The data is split into block of 5 symbols (byte or ECI mode identifier) or 6 codewords;
0 – 258 values are radix converted from five base 259 into six base 103 values;
0 – 255 values are byte values;
256, 257 or 258 values marks to encode ECI sequence in next 1, 2 or 3 bytes respectively;
Any DotCode codewords in the encoded sequence above 102 (from 103 to 112) interrupt or change mode.
As we see in the following table, Binary Latch encodes data more effectively, starting from 3 bytes.
ECI encoding
DotCode can encode ECI indicator int two ways:
In Binary Latch mode (reviewed upper);
With FNC2 character.
FNC2 in any position except at the end of data signals the insertion of an ECI sequence – "\nnnnnn", which represents values between 000000 and 811799. The values can be encoded in 1 or 3 codewords:
In case of next codeword < 40 directly encodes ECI value 000000 to 000039;
Otherwise, the next three codewords valued A, B, & C encode an ECI value of .
GS1 encoding
Any two digits in the position of the first codeword identify a symbol as GS1 encoded (opposite to Code 128). In case of symbol with two digits in the position of the first codeword must be decoded as ordinary data, the FNC1 (omitted in decoded message) must be inserted at the place of the first codeword. FNC1 in the other than the first position works as GS1 Application Identifier splitter and decoded as GS (ASCII value 29) character.
Codeword 100 in Code Set C encodes application GS1 AI (17) the next 3 codewords is an expiration date and inserts GS1 AI (10) before decoding other codewords:
(100)(24)(12)(30)(56)(64) -> 17241230105664
Macros mode
Some data codewords 97 – 100 in the lead data position in Code Set B can encode “Macros”. In any other position it encodes ASCII symbol:
(Latch B)(HT) -> [)>RS05GS … RSEoT
(Shift B)(HT) -> [)>RS05GS … RSEoT
Structured append
DotCode can create composite symbol, where data from multiple DotCode symbols can be logically united. This can be made with FNC2 symbol in last data position. When FNC2 is in the final data position, then the preceding two message characters, digits and uppercase letters in order 1 to 9 then A to Z (for values 10 to 35) shall as "m" and "n" designate where this message belongs in a "m out of n" sequence. As an example, a symbol whose message ends "4 B FNC2" shall be the 4th symbol out of 11 that comprise the entire message.
Special modes encoding
FNC3 in the first codeword position indicates that the message is the instructions for initialization or reprogramming of the bar code reader.
FNC3 in any other position than first indicates that encoded message must be logically separated into two distinct messages (before and after it);
Data padding
DotCode symbol codewords capacity is:
DotCode symbol data codewords capacity is:
In this way we need to pad data codewords in case with have free space. There are two rules:
Binary mode must be terminated with Latch to Code Set A (codeword 109);
In other modes codeword 106 (Latch to Code Set C / Latch to Code Set B) must be used.
See also
Automated identification and data capture (AIDC)
Barcode
Code 128
Extended Channel Interpretation
GS1
Hand Held Products
References
External links
DotCode patent
Free DotCode generator
Free DotCode reader
Automatic identification and data capture
Barcodes
Encodings | DotCode | [
"Technology"
] | 2,512 | [
"Data",
"Automatic identification and data capture"
] |
76,571,911 | https://en.wikipedia.org/wiki/Pnictogen%20bond | In chemistry, a pnictogen bond (PnB) is a non-covalent interaction, occurring where there is a net attractive force between an electrophilic region on a 'donor' pnictogen atom (Pn) in a molecule, and a nucleophilic region on an 'acceptor' atom, which may be in the same or another molecule. Closely related to halogen and chalcogen bonding, pnictogen bonds are a form of non-covalent interaction which can be considered in terms of charge-transfer and electrostatic interactions.
Physical origins
Pnictogen bonds typically demonstrate directionality, with the interaction forming either on a linear projection to the R–Pn bond (a σ-hole) or in a plane perpendicular to the three coplanar R–Pn bonds (a π-hole). In such cases, polarisation of the pnictogen atom by an electron-withdrawing substituent, results in an anisotropic electron distribution in the Pn atom affording a directional electropositive region, resulting in an attractive electrostatic interaction. As the polarisability of an atom increases upon descending the periodic table, pnictogen bond strengths typically increase upon descending pnictogen group, both as a result of increased poliarisation resulting in a greater electrostatic contribution to bonding, but also through increased dispersion interactions between the heavier PnB donor and the PnB acceptor atom.
Contributions to pnictogen bonding interactions can also arise through charge transfer interactions, in which a lone pair on the pnictogen bond acceptor are donated into a σ*-orbital on the pnictogen atom. Despite the charge transfer interaction, pnictogen bond interactions are non-covalent interactions, with X···Y bond lengths shorter than the sum of the van der Waals radii, but significantly longer than the sum of the covalent radii.
Applications
The directionality of σ-hole interactions, including PnB interactions, has resulted in their exploitation within the field of supramolecular chemistry, incorporating PnB donor systems into a range of systems exploiting the formation of weak intermolecular interactions for a range of applications.
Organocatalysis
PnB donors have been demonstrated to be capable of functioning as Lewis acidic catalysts. The first reported PnB catalysis cam in 2018 when PnB interactions were demonstrated to be potent catalysts for the Reissert reaction. Given their intermediate position in the main group of the periodic table, PnB catalysis may be appealing due to a balance between steric repulsion and polarisability factors.
Anion recognition
As for halogen and chalocogen bonding interactions, the σ-hole interactions in PnB hosts have been exploited for anion binding and recognition, with a report in 2022 exploiting a series of triaryl antinomy and bismuth receptors for binding of halide anions. The reported systems demonstrated selectivity for chloride from other halies and over the binding of oxoanions, in contrast to trends observed for hydrogen bonding systems, suggesting PnB interactions may have advantages in selective halide anion sensing over hydrogen bonding systems.
Transmembrane transport
PnB systems have also been shown to be capable of transmembrane anion transport, in which lipophilic organopnictogen compounds bind an anion through PnB interactions, enabling transport. The redox activity of main group systems enables the tuning of transport, in which 'on/off' switchable behaviour is enabled between an inactive carrier and an reduced carrier. Park and Gabbaï have demonstrated such a system, in which reduction of an adjacent sulfonium enables the transmembrane transport of anions by an antimony transporter.
References
See also
Sigma hole interactions
Non-covalent interactions
Chemical bonding
Intermolecular forces | Pnictogen bond | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 804 | [
"Molecular physics",
"Materials science",
"Intermolecular forces",
"Condensed matter physics",
"nan",
"Chemical bonding"
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76,572,141 | https://en.wikipedia.org/wiki/NGC%205996 | NGC 5996 is a barred spiral galaxy in the constellation Serpens. The galaxy lies about 125 million light years away from Earth, which means, given its apparent dimensions, that NGC 5996 is approximately 65,000 light years across. It was discovered by William Herschel on March 21, 1784.
NGC 5996 forms a pair with a smaller companion galaxy, NGC 5994, which lies at a distance of about 40,000 light years. The galaxy pair is known as Arp 72. The interaction of the two galaxies has created a long and faint tidal tail about 3.8 arcminutes long curving away from the northern edge of the disk of NGC 5996 towards the east and south. A hydrogen bridge has been observed between the two galaxies and hydrogen emission is also observed west of NGC 5994. The interaction has possibly induced star formation activity in NGC 5996 both in the nucleus and the disk, with a star formation rate of 1.43 per year. The brightest star cluster in the galaxy is estimated to be 5 million years old.
The galaxy pair is part of the NGC 5996 Group, which also includes UGC 10044 and IC 1135.
One supernova has been observed in NGC 5996, ASASSN-15db, which was discovered when it had an apparent magnitude of 16.7 and it was categorised as a type Ia supernova five days before maximum.
References
External links
Barred spiral galaxies
Interacting galaxies
Starburst galaxies
Serpens
5996
10033
72a
Markarian galaxies
+03-40-039
56023
Discoveries by William Herschel
Astronomical objects discovered in 1784
15447+1802 | NGC 5996 | [
"Astronomy"
] | 344 | [
"Constellations",
"Serpens"
] |
76,572,617 | https://en.wikipedia.org/wiki/Erwin%20N.%20Hiebert | Erwin Nick Hiebert (May 27, 1919 – November 28, 2012) was a Canadian-American physical chemist and historian of science. He taught numerous students who would go on to become leading figures in the history of science, particularly women such as Carolyn Merchant and Mary Jo Nye, during academic tenures at the University of Wisconsin–Madison and Harvard University. He contributed to the Manhattan Project as a research chemist before becoming a historian.
He published four books: on atomic energy; on the history of the principle of conservation of energy; on thermodynamics in the thought of Ernst Mach and Max Planck; and on the legacy of Hermann von Helmholtz in acoustics. He was the president of the History of Science Society for a two-year term from 1973 to 1974 and was president of the Division of the History of Science of the International Union of History and Philosophy of Science from 1982 to 1985.
Early life and education
Erwin N. Hiebert, whose father was a Mennonite minister, was born in Waldheim, Saskatchewan and grew up in an urban Russian Mennonite community in Winnipeg, Manitoba. He went to high school in Winnipeg and financed his own college education by working during summers and wheat harvests on Mennonite farms in Oklahoma, Kansas, Nebraska, and the Dakotas. He attended Tabor College in Hillsboro, Kansas for two years and then transferred to Bethel College in North Newton, Kansas, where he graduated in 1941 with a B.Sc. or B.A. degree, having studied chemistry and mathematics. In 1943 he graduated with an M.A. in chemistry and physics from the University of Kansas at Lawrence. He met Elfrieda Franz (1921–2012) while they both attended Tabor College and they married in 1943.
Soon after their marriage, the couple moved to Whiting, Indiana, where Hiebert became employed as a research chemist for a corporate laboratory of the Standard Oil Company of Indiana under the jurisdiction of the University of Chicago Metallurgical Laboratories as part of the Manhattan Project. He worked for the Standard Oil Company until 1946. From 1947 to 1948, he held the position of Assistant to the Chief of the Scientific Branch of the United States Department of War's General Staff in Washington, D.C. From 1948 to 1950 he worked as a research chemist at the Institute for the Study of Metals at the University of Chicago, where he graduated in 1949 with an M.Sc. in physical chemistry. At the University of Chicago, he was inspired by Alexander Koyré and Farrington Daniels to study the history of science.
In 1950, Hiebert began Ph.D. studies at the University of Wisconsin–Madison, in the History of Science and Physical Chemistry, which he completed in 1954. There, he was strongly influenced by the medieval sciences historian Marshall Claggett. By 1955, Erwin and Elfrieda Hiebert had three children, with the eldest born in 1948.
Career
During his years of study for his Ph.D., Hiebert was appointed to assistant professor of chemistry at San Francisco State College, a position he held 1952–1954. From 1954 to 1955 he resided in Germany to serve as a Fulbright Lecturer at the Max Planck Institute for Physics, then in Göttingen.
After returning to the US, Hiebert became an instructor in the history of science at Harvard University 1955 to 1957. In 1957, he and his family moved back to Madison, Wisconsin and remained there until 1970. There Hiebert was a faculty member in the University of Wisconsin–Madison's department of the history of science, and he chaired the department from 1960 to 1965. In 1959 he took part in a geophysical expedition to the Arctic. He published his first book, Impact of Atomic Energy, in 1961. He took academic leave for 1961–1962 and 1968–1969 to serve as a Fellow of the School of Historical Studies of Princeton Universtity's Institute for Advanced Study and he was an American Scholar in Kabul of the International Education Exchange Program in summer 1961, visiting professor at the University of Tübingen in 1964–1965, and visiting professor at Harvard University in 1965. In 1970 his wife Elfrieda Franz Hiebert, an accomplished musician, received a Ph.D. in musicology from the University of Wisconsin–Madison. Her Ph.D. thesis is entitled The piano trios of Beethoven: an historical and analytical study.
In 1970 Hiebert was appointed to a professorship at Harvard University and the Hiebert family settled in Belmont, Massachusetts. In 1972 he served as the pastor of the Mennonite Congregation of Boston, and he and his wife continued to serve on the congregation's Social Concerns Committee for decades. He held a professorship in Harvard's department of the history of science from 1970 to 1989, when he retired as professor emeritus. From 1977 to 1984 he chaired the department. During his professorship at Harvard, he took academic leaves to take visiting positions in Germany's Center for Interdisciplinary Research, Bielefeld (1973), Churchill College, Cambridge (1980, 1981, 1982, 1984–1985), the Hebrew University of Jerusalem (1981), the Chinese Academy of Sciences in Beijing (1985), and the University of Minnesota (1987).
Hiebert's doctoral students that he supervised or co-supervised include Jed Buchwald, Michael J. Crowe, Lorraine Daston, Peter Galison, Diana L. Kormos-Buchwald, Carolyn Merchant, Mary Jo Nye, Joan L. Richards, and Roger H. Stuewer. He was remembered by Mary Jo Nye as notably supportive of women scholars, unusually for his time: "The proportion of his students who are women was quite high (one of his early students was Carolyn Merchant). He gave us confidence, and he treated women like he treated the men. He always supported us in what we did, and I'm talking about the Sixties and early Seventies." Erwin and Elfrieda Hiebert welcomed students into their home and sometimes entertained their guests with impromptu musical performances; he played the clarinet and she played the piano.
For many years during his retirement, he continued to commute almost every day from Belmont to Harvard to work at Widener Library. In retirement, he was a visiting professor in Göttingen for the academic year 1991–1992 and in the Max Planck Institute of Berlin for visits in 1998, 2002, and 2007.
From 1970 to 1980 Hiebert was a member of the advisory committee of the multi-volume Dictionary of Scientific Biography, published by Charles Scribner's Sons. Hiebert, Robert Sonné Cohen, and Everett Mendelsohn were the general editors of D. Reidel's book series Studies in the History of Science.
He was elected in 1966 a fellow of the American Association for the Advancement of Science, in November 1971 a membre correspondant of the Académie Internationale d'Histoire des Sciences, for 1973–1974 the president of the History of Science Society, in 1975 a fellow of the American Academy of Arts and Sciences, for 1982–1985 president of the Division of the History of Science of the International Union of History and Philosophy of Science, and in 1989 a fellow of the American Physical Society. In 1992 a festschrift was published in his honor.
Research
The focus of Hiebert's research was the history and philosophy of chemistry and physical sciences in the 2nd half of 19th century and 1st half of the 20th century. During his lifetime he completed three books and his fourth book (which deals with acoustics) was nearly complete at the time of his death. His book 1961 book Impact of Atomic Energy examined the Manhattan Project, the atomic bombings of Hiroshima and Nagasaki, and World War II's consequences related to atomic energy from an ethical and religious perspective. He wrote numerous papers on the history of science, the relations between science and religion, and the philosophy of science as viewed by outstanding scientists of the modern era, especially among those scientists from 1850 to 1930 in Germany and Austria. His 1962 book Historical Roots of the Principle of Conservation of Energy is a notable achievement in writing the history of thermodynamics. He wrote papers about the science and philosophy of Max Planck, Ernst Mach, Walther Nernst, Ludwig Boltzmann, Hermann von Helmholtz, and Wilhelm Ostwald. Hiebert
had a strong conviction that historians of science should have a good, scientific grounding in the particular science that they study and write about.
Family
Hiebert died in Waltham, Massachusetts in November 2012, shortly after his wife of 69 years died in September 2012. They had two daughters and a son. Their daughter Margaret Hiebert Beissinger, married to Mark Beissinger, became a professor of Slavic languages and Slavic literature at Princeton University.
Selected publications
Articles
Books
References
1919 births
2012 deaths
Bethel College (Kansas) alumni
University of Kansas alumni
University of Chicago alumni
University of Wisconsin–Madison alumni
University of Wisconsin–Madison faculty
Harvard University faculty
Historians of science
Historians of physics
Physical chemists
American male non-fiction writers
Canadian male non-fiction writers
Canadian emigrants to the United States
Fellows of the American Academy of Arts and Sciences
Fellows of the American Association for the Advancement of Science
Fellows of the American Physical Society | Erwin N. Hiebert | [
"Chemistry"
] | 1,882 | [
"Physical chemists"
] |
76,572,980 | https://en.wikipedia.org/wiki/Surface%20Go%204 | The Surface Go 4 For Business is the fourth generation model of the Surface Go series of devices, targeted at businesses rather than consumers, introduced as the successor to the Surface Go 3 For Business by Microsoft at their Surface Event on September 21, 2023. The tablet runs Windows 11 Pro. The Surface Go 4 was the first business-only product in the Surface Go series
Features
Windows 11 operating system
12th Gen Intel N200 processor
10.5-inch PixelSense™ Display
Windows Hello with IR camera for facial recognition logon
Intel UHD Graphics GPU
Software
Surface Go 4 is only powered by Windows 11 Pro in Windows 11#Versions
The device also supports Windows Hello login using a biometric facial recognition.
Timeline
References
External links
Tablet computers introduced in 2023
Microsoft Surface
2-in-1 PCs | Surface Go 4 | [
"Technology"
] | 160 | [
"Crossover devices",
"2-in-1 PCs",
"Computing stubs",
"Computer hardware stubs"
] |
76,573,038 | https://en.wikipedia.org/wiki/PHL%205038 | PHL 5038AB (or just PHL 5038) is a binary system consisting out of a white dwarf and a brown dwarf on a wide orbit. The system is 240 light years (74 parsec) distant from earth.
The white dwarf PHL 5038A was discovered in 2006 in data from the Sloan Digital Sky Survey and the brown dwarf companion was discovered in 2009 from UKIDSS infrared excess and confirmed with Gemini North to be a spacially resolved binary. It was only the fourth known brown dwarf to orbit a white dwarf at the time. The others were GD 165B, WD 0137-349B and GD 1400B.
Physical parameters
The white dwarf was first classified as a DA white dwarf, which indicates a hydrogen-dominated atmosphere without any metal pollution. A later work found weak pollution due to calcium in the atmosphere of the white dwarf thanks to XSHOOTER spectra from the Very Large Telescope. The calcium is detected as the K-line in two spectra. No infrared excess due to a disk was detected. PHL 5038A has either accreted all debris or is surrounded by a thin disk. The mass and temperature was also overestimated in the past and later works found a mass of around 0.53 to 0.57 , an effective temperature of around 7500 to 7800 Kelvin and a surface gravity of around 7.9 dex. The progenitor main-sequence star had a mass of around 1.07 and it existed for around 9 billion years until it became an AGB star and around 1 billion years ago it became a white dwarf.
The brown dwarf has a spectral type of around L8-L9. Its mass was initially estimated to be 60 , but this mass was likely an underestimate and more recent estimates find a mass of around 0.070 (or 73 ) and an effective temperature of 1425 K.
The same team that discovered the metal pollution of the white dwarf also re-observed the system with Gemini North to determine the orbital parameters. The semi-major axis is astronomical units and the inclination is 132 ±11°. The eccentricity is unconstrained, but likely lower than 0.615. In the past the white dwarf was more massive, making the semi-major axis half as large at 33 AU.
Evolution
Casewell et al. suggest the following evolution of the system:
The PHL 5038 system during the main-sequence had a star with a mass similar or more massive than the sun and it had a brown dwarf at an orbit of 33 AU, similar to the orbital distance of Neptune. It also likely had rocky debris in the form of planetesimals in orbit around the star, maybe similar to the asteroid belt. At the end of its lifetime the star became an AGB star with a size smaller than 2.5 AU, leaving the rocky debris mostly intact. As the star lost around half of its mass, the orbit of the brown dwarf and the planetesimals increased. The debris would be stable within 17-32 AU (circular orbit of the brown dwarf) or 5-8 AU (e=0.6 for the brown dwarf orbit). A debris belt with an increased size might be close to the edge of this stable zone and gravitational interactions with the brown dwarf would scatter planetesimals into all kinds of directions, eroding the edge of the debris belt. Some of these planetesimals will be scattered inwards and are being disrupted by the tidal forces of the white dwarf, leading to the pollution of the white dwarf atmosphere. Alternatively the disk could have been larger than the stable zone, resulting in chaotic scattering at the beginning of the white dwarf stage, until the scattering decreased.
See also
List of exoplanets and planetary debris around white dwarfs
GD 165B is the first brown dwarf discovered around a white dwarf
References
White dwarfs
L-type brown dwarfs
Binary stars
Aquarius (constellation) | PHL 5038 | [
"Astronomy"
] | 804 | [
"Constellations",
"Aquarius (constellation)"
] |
76,577,739 | https://en.wikipedia.org/wiki/Branched%20chain%20amino%20acid%20exporter%20family | specific transmembrane protein complexes called Branched Chain Amino Acid Exporters (LIV-E) mediate the export of branched chain amino acids out of prokaryotic cells.
Branched chain amino acids (BCAAs) — isoleucine, leucine, and valine — are critical nutrients in bacterial physiology with roles in protein synthesis and signaling. Regulating the cytosolic level of BCAAs is necessary for cell growth and adaptation. LIV-E transporters are categorized as electrochemical potential-driven transporters, subcategory porters (2.A.78) in the Transporter Classification Database. LIV-E transporters are antiporters that use the proton motive force, catalyzing the transport of two hydrogen ions inside the cell, to obtain the energy to export one amino acid out of the cell.
All LIV-E complexes are formed from two separate transmembrane proteins. Though no structure of a LIV-E transporter exists, both proteins are necessary for function and it is assumed they form a heterodimeric complex within the membrane.
Phylogeny
One study in the early 2000's investigated the phylogeny of the LIV-E family. It found that LIV-E transporters are prevalent across many prokaryotic organisms, including archaea and both Gram-positive and Gram-negative bacteria. While many species only encode one LIV-E transporter, other species encode multiple paralogs. Notably, these paralogs are highly divergent, suggesting early gene duplication events and independent functions for each paralog. By contrast, in some species like Methanococcus jannaschii and Neisseria meningitidis, only one of the two components of the transporter, and consistently only the larger component, is found. It is not known if these single genes encode a functional transporter. Multiple instances of highly similar LIV-E transporters have been found in both closely related and distantly related species, suggesting inheritance of LIV-E transporters has occurred both from ancestral lineages and by horizontal gene transfer across divergent species.
Transporter function
Characterized LIV-E transporters include BrnFE in Corynebacterium glutamicum, AzlCD in Bacillus subtilis, and YgaZH in Escherichia coli.. The most comprehensive functional characterizations have been performed for BrnFE. However, the earliest functional role of a LIV-E transporter was described for AzlCD. In Bacillus subtilis, overexpression of AzlCD causes resistance to 4-azaleucine, a toxic analogue of leucine. Despite this function, AzlCD does not likely play a major role in branched-chain amino acid homeostasis in this species.
In Corynebacterium glutamicum, BrnFE exports branched chain amino acids isoleucine, leucine, and valine, as well as methionine and homoserine. The greatest induction of BrnFE expression occurs under high methionine concentrations, suggesting that methionine may actually be the native substrate rather than a branched-chain amino acid.
Transporter regulation
LIV-E transporters in Gram-negative bacteria have often been found to be regulated by, or even co-transcribed in one operon with, the important nutrient regulator Lrp (leucine responsive protein). The regulon for Lrp is not entirely conserved across species, but often regulates amino acid uptake and biosynthesis. Lrp activity is induced by interaction with leucine, such that in environments rich in leucine the cell does not expend energy acquiring or producing its own branched-chain amino acids. Co-transcription of Lrp and a LIV-E amino acid exporter creates a negative regulatory feedback loop. Lrp is first expressed and activated under high nutrient conditions, then the LIV-E transporter exports nutrients to lower intracellular concentrations and reduce activation of Lrp, turning off the system.
Applications in industrial amino acid production
The regulatory relationship between Lrp and a LIV-E transporter has been used in both Corynebacterium glutamicum and Escherichia coli, where alterations to either or both Lrp and BrnFE or AzlCD, respectively, lead to an increase in amino acid biosynthesis. As Corynebacterium glutamicum is commonly used in the industrial production of amino acids, these alterations have made important improvements in amino acid yields.
Studies into BrnFE have also been applied to create a biosensor of high nutrient concentration. As the promoter for BrnFE in Corynebacterium glutamicum is induced under high concentrations of methionine and branched-chain amino acids, and Lrp is induced under the same conditions, researchers have created a hybrid construct of Lrp driven by the promoter for BrnFE (Lrp-PbrnFE). Further engineering of a desired target genes with an Lrp-binding sequence allows for the specific activation of target gene expression under high concentrations of branched-chain amino acids. This system has been utilized to drive expression of YFP as a visual marker for cells with high intracellular methionine or branched-chain amino acid concentration, which is then used to screen for genetic mutants that produce higher concentrations of these amino acids for industrial production.
References
Protein families
Transmembrane proteins | Branched chain amino acid exporter family | [
"Biology"
] | 1,121 | [
"Protein families",
"Protein classification"
] |
76,579,486 | https://en.wikipedia.org/wiki/Local%20telephone%20area%20codes%20in%20France | Local telephone area codes in France allowed, until 2022, the identification of a traditional landline subscriber's geographic area, with the exception of non-geographic phone numbers beginning with the prefix 09 - such as VoIP numbers provided with triple play subscriptions. Since 1 January 2023, geographic location is no longer required to correspond to local area codes.
Area codes are issued by default with the prefix 0 by telephone carriers. The area codes are defined as the second "Z" digit in the dialing encoding pattern E Z AB PQ MCDU.
French territory (except for Pacific Ocean dependencies, which have their own dialing patterns) was divided into five broad areas grouping multiple regions between 18 October 1996 and 1 January 2023. These divisions are defined by ARCEP.
Area codes:
01 : Île-de-France region
02 : Northwest region: (Brittany, Centre-Val de Loire, Normandy, Pays de la Loire) and "Indian Ocean" (Réunion and Mayotte).
03 : Northeast region: Bourgogne-Franche-Comté, Grand Est, and Hauts-de-France.
04 : Southeast region: Auvergne-Rhône-Alpes, Corsica, Provence-Alpes-Côte d'Azur, andOccitania (Languedoc-Roussillon).
05 : Southwest region: Nouvelle-Aquitaine and Occitania (Midi-Pyrénées). Other departments, collectivities, and overseas territories: Guadeloupe, Martinique, and French Guiana.
: The departmental code is defined by the third and fourth "AB" digits in the dialing encoding pattern E Z AB PQ MCDU. These areas don't necessarily correspond to the departmental limits; each zone can contain multiple departments.
: Smaller, more precise area codes also exist, defined by the third to the sixth "AB PQ" digits in the dialing encoding pattern E Z AB PQ MCDU. These codes (numbering around 17000 in France) are grouped by areas known as elementary dialing area codes (such as 420 for all of France, and 412 for the mainland).
: Area codes don't consider newer regions. Thus, Occitania is split between two area codes: 04 for Languedoc-Roussillon and 05 for Midi-Pyrénées.
Other prefixes are dedicated to specific uses, for example 06 and 07 to mobile numbers. (List of area codes of mobile carriers in France).
The portability of local area code phone numbers — in terms of porting a landline number — is permitted since January 2020 within the five metropolitan areas, and since January 2024, within all of metropolitan France.
Starting 1 January 2023, certain area codes are reserved for telemarketing platforms and became the only codes authorised for this use.
List of departmental area codes by geographic location
Note :
- Area codes without an assignment date were assigned after 31 October 1996.
- Departments that did not have a code at a given point were assigned re-used codes.
List of departmental area codes by department
See also
Telephone numbers in France
Liste des préfixes des opérateurs de téléphonie par internet en France
Liste des préfixes des opérateurs de téléphonie mobile en France
Anciens indicatifs téléphoniques à Paris
Anciens indicatifs téléphoniques régionaux en France
Notes and References
External links
ARCEP
ARCEP dialing site
Telecommunications in France
Telecommunications lists
Telephone numbers | Local telephone area codes in France | [
"Mathematics"
] | 709 | [
"Mathematical objects",
"Numbers",
"Telephone numbers"
] |
76,582,517 | https://en.wikipedia.org/wiki/LogoFAIL | LogoFAIL is a security vulnerability and exploit thereof that affects computer motherboard firmware with TianoCore EDK II, including Insyde Software's InsydeH2O modules and similar code in AMI and Phoenix firmware, which are commonly found on both Intel and AMD motherboards, and which enable loading of custom boot logos. The exploit was discovered in December 2023 by researchers at Binarly.
Description
The vulnerability exists when the Driver Execution Environment (DXE) is active after a successful Power On Self Test (POST) in the UEFI firmware (also known as the BIOS). The UEFI's boot logo is replaced with the exploit payload at this point, and the exploit can then take control of the system.
Patches
Intel patched the issue in Intel Management Engine (ME) version 16.1.30.2307 in December 2023. AMD addressed the problem in AGESA version 1.2.0.b, although some motherboard manufacturers did not include the fix under AGESA 1.2.0.c.
External links
CVE-2023-40238
Binarly analysis of LogoFAIL
References
2024 in computing
Computer security exploits
X86 architecture | LogoFAIL | [
"Technology"
] | 251 | [
"Computer security stubs",
"Computing stubs",
"Computer security exploits"
] |
77,992,485 | https://en.wikipedia.org/wiki/Prey%20naivet%C3%A9 | Prey naïveté hypothesis is a theory that suggests that native prey often struggle to recognize or avoid an introduced predator because they lack a coevolutionary history with it. Prey naïveté is believed to intensify the effects of non-native predators, which can contribute significantly to the risks of extinction and endangerment of prey populations.
Overview
The prey naïveté hypothesis suggests that ineffective antipredator defenses result from a lack of evolutionary exposure to specific predators. This naiveté towards non-native predators is likely influenced by eco-evolutionary factors such as biogeographic isolation and prey adaptation. A prey species' ability to detect and evade predators can be shaped by the life history, ecology, and evolutionary context of both predator and prey. While some predator-prey systems display species-specific avoidance behaviors, many taxa require learned olfactory recognition of predators. Certain antipredator behaviors that develop in response to coevolved predators may persist over time, even in their absence, particularly when other predators are present, as suggested by the "multipredator hypothesis."
For instance, rats introduced to oceanic islands have been implicated in the extinction of many mammals, birds, and reptiles that lack evolutionary experience with generalist mammalian nest predators. However, the negative effects of rats are lessened on islands with native rats or functionally similar land crabs, as the fauna on these islands appear to be less naïve to the threats posed by introduced omnivores. Prey are generally naïve towards non-native predators in marine and freshwater environments, but not in terrestrial ones. The naïveté was most significant towards non-native predators lacking native relatives in the community. Time since introduction plays a role, with prey naïveté diminishing over generations; approximately 200 generations may be needed for prey to sufficiently develop antipredator behaviors towards these non-native threats.
Driving factors
The occurrence and intensity of prey naiveté are hypothesized to arise from several interrelated factors, categorized into four themes:
Biogeographic isolation: Prey naiveté is thought to be exacerbated by evolutionary isolation between predator and prey, particularly in freshwater environments. Island ecosystems may also experience heightened naiveté due to lack of eco-evolutionary experience with both non-native and native predators.
Adaptation over time: Prey may acquire effective antipredator responses over generations following the introduction of a predator, with naiveté diminishing as prey adapt.
Latitude and biodiversity: The latitude of predator introduction may influence prey recognition, with lower latitudes possibly exhibiting higher recognition rates due to greater predation pressure and biodiversity.
Taxonomic specificity: Recognition of introduced predators may vary by taxonomic group, suggesting that certain prey species are better equipped to recognize specific predators.
Levels of prey naiveté
Prey naiveté was initially conceptualized as a straightforward phenomenon in which native fauna become vulnerable to non-native predators due to naive behavioral responses. It is now understood to be a multifaceted issue, and is classified into four distinct levels:
In addition to behavioral inadequacies, prey species lacking evolutionary exposure to non-native predation may possess morphological or physiological traits that render them more susceptible to such threats, including insufficient defensive structures, flightlessness, conspicuous odors, or inadequate camouflage. Although prey naiveté is widely recognized in ecological studies, its variability under the influence of eco-evolutionary factors is not yet fully quantified.
Impact
Prey naïveté contributes significantly to the extinction and endangerment of prey species globally, as well as to the failure of wildlife reintroductions.
Mitigation
While excluding novel predators from conservation areas has had mixed results, the absence of any predators can worsen prey naiveté. Reintroducing native predators has been proposed as a potential solution to enhance prey behavioral responses. A study published in 2024 assessed the behavioral reactions of two prey species—the burrowing bettong (Bettongia lesueur) and spinifex hopping mouse (Notomys alexis)—to the reintroduction of a native predator, the western quoll (Dasyurus geoffroii), and its impact on their responses to feral cats (Felis catus). Results indicated that quoll-exposed bettongs engaged in less inattentive foraging compared to controls but did not differentiate between predator and non-predator cues. In contrast, quoll-exposed hopping mice adjusted their foraging behaviors in open areas and increased their wariness in response to quoll stimuli, while cat-exposed hopping mice only heightened their caution in the presence of cat stimuli. Although reintroducing native predators improved general antipredator responses among naïve prey populations, evidence for enhanced discrimination towards introduced predators was limited, although the findings suggest that exposure to native predators may better prepare naïve prey for environments where novel predators are present.
A 2019 study explored whether exposing predator-naïve prey, specifically the greater bilby (Macrotis lagotis), to controlled numbers of introduced predators (feral cats, Felis catus) can enhance their survival upon reintroduction. Over two years, bilbies were exposed to feral cats in a fenced area, and their behaviors were assessed. Results showed that predator-exposed bilbies exhibited increased wariness—spending less time moving and more time in cover—compared to naïve bilbies. Following translocation, the predator-exposed group had higher survival rates and was less likely to be predated upon than their naïve counterparts. The study suggests that training naïve prey in the presence of predators may improve their survival in reintroduction efforts.
References
Ecology
Predation
Ecological theories | Prey naiveté | [
"Biology"
] | 1,127 | [
"Ecology"
] |
77,992,820 | https://en.wikipedia.org/wiki/Random%20feature | Random features (RF) are a technique used in machine learning to approximate kernel methods, introduced by Ali Rahimi and Ben Recht in their 2007 paper "Random Features for Large-Scale Kernel Machines", and extended by. RF uses a Monte Carlo approximation to kernel functions by randomly sampled feature maps. It is used for datasets that are too large for traditional kernel methods like support vector machine, kernel ridge regression, and gaussian process.
Mathematics
Kernel method
Given a feature map , where is a Hilbert space (more specifically, a reproducing kernel Hilbert space), the kernel trick replaces inner products in feature space by a kernel functionKernel methods replaces linear operations in high-dimensional space by operations on the kernel matrix: where is the number of data points.
Random kernel method
The problem with kernel methods is that the kernel matrix has size . This becomes computationally infeasible when reaches the order of a million. The random kernel method replaces the kernel function by an inner product in low-dimensional feature space : where is a randomly sampled feature map .
This converts kernel linear regression into linear regression in feature space, kernel SVM into SVM in feature space, etc. Since we have where , these methods no longer involve matrices of size , but only random feature matrices of size .
Random Fourier feature
Radial basis function kernel
The radial basis function (RBF) kernel on two samples is defined as
where is the squared Euclidean distance and is a free parameter defining the shape of the kernel. It can be approximated by a random Fourier feature map :where are IID samples from the multidimensional normal distribution .
Since are bounded, there is a stronger convergence guarantee by Hoeffding's inequality.
Random Fourier features
By Bochner's theorem, the above construction can be generalized to arbitrary positive definite shift-invariant kernel .
Define its Fourier transformthen are sampled IID from the probability distribution with probability density . This applies for other kernels like the Laplace kernel and the Cauchy kernel.
Neural network interpretation
Given a random Fourier feature map , training the feature on a dataset by featurized linear regression is equivalent to fitting complex parameters such thatwhich is a neural network with a single hidden layer, with activation function , zero bias, and the parameters in the first layer frozen.
In the overparameterized case, when , the network linearly interpolates the dataset , and the network parameters is the least-norm solution:At the limit of , the L2 norm where is the interpolating function obtained by the kernel regression with the original kernel, and is the norm in the reproducing kernel Hilbert space for the kernel.
Other examples
Random binning features
A random binning features map partitions the input space using randomly shifted grids at randomly chosen resolutions and assigns to an input point a binary bit string that corresponds to the bins in which it falls. The grids are constructed so that the probability that two points are assigned to the same bin is proportional to . The inner product between a pair of transformed points is proportional to the number of times the two points are binned together, and is therefore an unbiased estimate of . Since this mapping is not smooth and uses the proximity between input points, Random Binning Features works well for approximating kernels that depend only on the distance between datapoints.
Orthogonal random features
Orthogonal random features uses a random orthogonal matrix instead of a random Fourier matrix.
Historical context
In NIPS 2006, deep learning had just become competitive with linear models like PCA and linear SVMs for large datasets, and people speculated about whether it could compete with kernel SVMs. However, there was no way to train kernel SVM on large datasets. The two authors developed the random feature method to train those.
It was then found that the variance bound did not match practice: the variance bound predicts that approximation to within requires , but in practice required only . Attempting to discover what caused this led to the subsequent two papers.
See also
Kernel method
Support vector machine
Fourier transform
Monte Carlo method
References
External links
Random Walks - Random Fourier features
Machine learning
Monte Carlo methods
Kernel methods for machine learning | Random feature | [
"Physics",
"Engineering"
] | 845 | [
"Monte Carlo methods",
"Artificial intelligence engineering",
"Machine learning",
"Computational physics"
] |
77,993,336 | https://en.wikipedia.org/wiki/Light%20Travel%20Time%20Effect | The light travel time effect is defined as the differences that occur in the periodic eclipses of binary stars when they are disturbed by another massive object.
The periods of the orbits in an undisturbed eclipsing binary star system stay relatively stable, since the center of mass does not change in position. A more massive object can disturb the center of mass of the binary system and thus change the periodic nature of the orbits in the binary. The disturbance caused by this larger object causes the system to be farther away or closer to the observer at times, causing the timings of the eclipses in the binary to change.
If the binary systems have planets, the more massive object can cause transit-timing variations in the orbiting planets.
References
Astronomical dynamical systems
Concepts in stellar astronomy | Light Travel Time Effect | [
"Physics",
"Astronomy",
"Mathematics"
] | 156 | [
"Concepts in astrophysics",
"Astronomy stubs",
"Astronomical dynamical systems",
"Concepts in stellar astronomy",
"Astronomical objects",
"Dynamical systems"
] |
77,995,476 | https://en.wikipedia.org/wiki/Phenatine | Phenatine, or phenatin, also known as N-nicotinoylamphetamine and sold under the brand name Fenatine, is a psychostimulant of the amphetamine family which was developed and used in the Soviet Union. It was used in the treatment of depression, narcolepsy, post-encephalitis sequelae, alcoholic psychoses, asthenia, and other conditions.
Chemistry
Phenatine is a condensation product of amphetamine (phenamine) and nicotinic acid (niacin; vitamin B3). It was first described in the scientific literature by 1955.
Pharmacology
Phenatine is described as having effects analogous to those of amphetamine. Phenatine was also said to enhance physical and mental performance. However, the drug was described as being a milder stimulant than amphetamine whilst supposedly being superior to amphetamine and other stimulants in various respects. It was claimed to be much less toxic than amphetamine, to have hypotensive rather than hypertensive effects (and hence to not be contraindicated in people with hypertension), and to have reduced rebound effects and addictive potential.
Analogues
An analogue is methylphenatine. Another analogue is pyridoxiphen (pyridoxiphene; pyridoxylamphetamine), the condensation product of amphetamine and pyridoxine (vitamin B6). Other relatives may include thiophenatine, propylphenamine, and phenylphenamine. Further analogues of phenatine and pyridoxphen include gamofen (the condensation product of amphetamine and γ-aminobutyric acid (GABA)), alafen (the condensation product of amphetamine and β-alanine), and pabofen (p-aminobenzoylamphetamine; linkage of amphetamine and p-aminobenzoic acid (PABA), an intermediate in the biosynthesis of folic acid (vitamin B9)), all of which show distinct pharmacological activity.
See also
Benzphetamine
Clobenzorex
Lisdexamfetamine
N-t-BOC-MDMA
List of Russian drugs
References
External links
Phenatine (Monograph ID: M8600) - The Merck Index Online
Abandoned drugs
Amides
Antihypertensive agents
Drugs in the Soviet Union
Nicotinates
Phenyl compounds
Pyridines
Russian drugs
Russian inventions
Stimulants
Substituted amphetamines | Phenatine | [
"Chemistry"
] | 556 | [
"Amides",
"Drug safety",
"Functional groups",
"Abandoned drugs"
] |
77,997,346 | https://en.wikipedia.org/wiki/Floor%20timber | In wooden ships, floor timber is the support below the flooring plank. As modern ships are not made of timber, the same concept is known by several names; bulkhead, transversal frame or side girder. This steel framing is usually made with lightening holes. If floor timbers lay tight between the floor and the hull, bulkhead compartments are created.
In modern ships, the inside space at the bottom produced by transversal frames are called bilges in plural, singular for the external side or bilge.
History
Roman era boats (2nd century AD) found in the Lower Rhine, current Netherlands, employed this structural style. In Roman corbita merchant ships (1st century AD), bulkheads were formed between the floor and hull due to transversal floor timbers.
English appears to lack a specific word for this sort of wooden transversal frames, however in several Romance languages, the specific word "varangue" and "varenga" for floor timber appears to be derived from old Norman around 1379.
The style was also employed in ships during the Age of Sail.
References
Sailing ship components | Floor timber | [
"Engineering"
] | 230 | [
"Naval architecture",
"Marine engineering"
] |
78,000,772 | https://en.wikipedia.org/wiki/Rob%20%22Reef%22%20Tewlow | Rob Tewlow, professionally known by his moniker Reef, is an American musician, record producer and audio engineer from New York City. He is a former music journalist at The Source and a former A&R music executive for Atlantic Records' hip-hop department. He also worked at the Sirius XM's station's hip-hop channel Shade 45 as an executive.
Tewlow was brought by editor Matteo "Matty C" Capuluongo to work as a music reviewer and photographer for hip-hop magazine The Source, where he contributed from 1991 to 1992 before leaving to work as an A&R at Atlantic Records. In 1992, he signed hip hop duo Artifacts, composed of Tame One and El Da Sensei, to Big Beat Records.
As a record producer, Tewlow helmed his hip hop production on Bad Meets Evil's "Nuttin' to Do" and "Scary Movies", 50 Cent's "What Up Gangsta" and Doja Cat's "Tonight", also producing for the likes of Hussein Fatal, The High & Mighty, Fat Joe, Trick Daddy, B Rich, Royce da 5′9″, Cage, Dilated Peoples and Yo Gotti. On July 12, 2011, Jon Connor released his digital album, which was produced entirely produced by Tewlow.
At the 64th Annual Grammy Awards held on 2022, he was nominated for a Grammy Award for Album of the Year for his production duties on Doja Cat's Planet Her (Deluxe).
Production discography
1990s
1994: Down South — "Sitting Here" from Lost In Brooklyn (co-prod.; prod. by Shawn J Period)
1996: Sadat X & Grand Puba — "The Next Spot" from High School High: The Soundtrack (add. prod.; prod. by Dante Ross, Grand Puba & Sadat X)
1997: Artifacts — "Art of Scratch (Intro)" from That's Them
1997: Mobb Deep — "The After Hours G.O.D. Pt. III" (add. prod. w/ DJ Mighty Mi; prod. by Mobb Deep)
1997: Ill-Advised — "Gimme tha Mic" from Can U Smell It
1998: Hussein Fatal — "I Know the Rules" and "Getto Star" from In the Line of Fire
1998: Bad Meets Evil — "Nuttin' to Do" and "Scary Movies"
1998: Mad Skillz — "The Conceited Bastard"
1998: Mr. Eon, Baby Blak & Pauly Yamz — "All in Together" from Eastern Conference All Stars (prod. w/ DJ Mighty Mi)
1999: The High & Mighty — "The Half" and "Weed" from Home Field Advantage
2000s
2000: Triple Seis — "Some Shit" and "Roll Till We Bankrupt"
2001: Fat Joe — "Fight Club" from Jealous Ones Still Envy (J.O.S.E.)
2002: Trick Daddy — "Rain It Pours" from Thug Holiday
2002: B Rich — "Playin' Games" from 80 Dimes (add. prod. by Mike Caren)
2002: The High & Mighty — "Nowhere to Hide At" from Air Force 1
2002: Royce da 5′9″ — "Take His Life", "Nickel Nine Is..." and "Soldier's Story" from Rock City
2003: Triple Seis — "Coast 2 Coast" and "Godfather" from Only Time'll Tell
2003: 50 Cent — "What Up Gangsta" from Get Rich or Die Tryin'
2003: Tame One — "Dreamz" from When Rappers Attack
2003: Cage — "Leak Bros." from Weatherproof
2003: Jamelia — "Superstar (Rob 'Reef' Tewlow Remix)"
2003: The High & Mighty & R.A. the Rugged Man — "Betcha Life" from The Highlite Zone (co-prod.; prod. by DJ Mighty Mi)
2003: The High & Mighty, Cage & Tame One — "Live From the Bullpen" from The Highlite Zone
2004: Royce da 5′9″ — "What I Know" from Death Is Certain
2004: Dilated Peoples — "Tryin' to Breathe" from Neighborhood Watch
2004: Royce da 5′9″ & Kid Vishis — "Brothers Keeper" from The M.I.C. Official Mixtape
2004: The UN — "It's Over" from Eastern Conference All Stars IV
2010s
2011: Jon Connor — Salvation
2016: Yo Gotti — "I Remember" from White Friday (CM9)
2020s
2021: Doja Cat — "Tonight" from Planet Her (Deluxe)
Other credits
Big Beat/Atlantic Records
1992: O.F.T.B. — Straight Up Watts (A&R coordinator)
1992: Double X Posse — Put Ya Boots On (A&R coordinator)
1994: Artifacts — Between a Rock and a Hard Place (executive producer, A&R direction)
Artifacts — "Wrong Side of da Tracks" (executive producer, A&R direction, editing)
Artifacts — "C'mon wit da Git Down" (executive producer, A&R)
Artifacts — "Dynamic Soul" (executive producer, A&R)
1994: Down South – Lost In Brooklyn (A&R direction)
Down South – "Southern Comfort" (mixing)
Down South – "Tractors, Rakes, and Hoes" (mixing)
Down South – "Sitting Here" (mixing)
1994: DFC – "Digga Bigga Ditch (Evil Radio Mix)" (mixing)
1995: Junior M.A.F.I.A. – Conspiracy (A&R coordinator)
1995: Double X Posse — Ruff, Rugged & Raw (executive producer, A&R direction)
Double X Posse — "He Asked For It"/"Make Some Noise" (executive producer)
Double X Posse — "Stop That Playin'"/"Wreckin' It"/"The Ill Real" (executive producer)
1996: Mad Skillz — From Where??? (executive producer, A&R direction)
Mad Skillz — "The Nod Factor" (executive producer)
Mad Skillz — "Move Ya Body" (executive producer)
1996: Real Live — The Turnaround: The Long Awaited Drama (A&R)
Real Live — "Real Live Shit" (A&R)
Real Live — "Real Live Shit (Remix)" (executive producer, A&R)
Real Live — "The Turnaround" (A&R)
1996: Music From And Inspired By The Motion Picture High School High (associate producer)
Sadat X & Grand Puba — "The Next Spot" (mixing)
1997: Artifacts — That's Them (executive producer, A&R)
Artifacts — "Art of Facts" (A&R)
Artifacts — "The Ultimate" (executive producer, A&R)
Loud/RCA Records
1997: Mobb Deep — "The After Hours G.O.D. Pt. III" (re-mixing)
Game Recordings
1998: Bad Meets Evil — "Nuttin' to Do"/"Scary Movies" (mixing)
Terror Squad/Big Beat/Atlantic Records
1998: Fat Joe — Don Cartagena (co-executive producer, A&R)
Fat Joe — "Bet Ya Man Can't (Triz)" (co-executive producer)
Fat Joe — "Misery Needs Company" (keyboards, additional programming)
Eastern Conference Records
1998: Mad Skillz — "The Conceited Bastard" (executive producer)
Atlantic Records
1998: Nicole Renée — "The Boy Next Door" from Nicole Renée (drum programming)
Game Recordings
1999: Royce da 5′9″ — "Take His Life" (mixing)
Rawkus Records
1998: KRS-One, Zack de La Rocha & The Last Emperor — "CIA (Division-I Remix)" (arranger)
1999: The High & Mighty — "Dick Starbuck "Porno Detective"" from Home Field Advantage (additional drum programming)
1999: The High & Mighty — "The Half" and "Weed" from Home Field Advantage (mixing)
1999: The High & Mighty — "Hands On Experience Pt. II" from Home Field Advantage (drum programming)
Terror Squad/Big Beat/Atlantic Records
1999: Terror Squad — The Album (co-executive producer, A&R)
Terror Squad — "Whatcha Gon Do" (co-executive producer)
Terror Squad — "All Around the World" (mixing)
Game Recordings
2000: Royce da 5′9″ — "Soldier's Story" (mixing)
Terror Squad/Atlantic Records
2000: Cuban Link — "Flowers for the Dead" (executive producer)
Atlantic/Warner Sunset Records
2000: Music From The Motion Picture Any Given Sunday (A&R)
Terror Squad/Atlantic Records
2001: Fat Joe — Jealous Ones Still Envy (J.O.S.E.) (co-executive producer, A&R)
Fat Joe — "We Thuggin'" (co-executive producer, A&R)
Fat Joe — "What's Luv?" (co-executive producer)
2002: Fat Joe — Loyalty (co-executive producer, A&R)
Fat Joe — "Fight Club" (executive producer)
Eastern Conference Records
2003: Cage — "Leak Bros" from Weatherproof (mixing, arrangement)
Parlophone
2003: Jamelia — "Superstar (Rob 'Reef' Tewlow Remix)" (mixing, arrangement)
VP Records
2003: Wayne Wonder, Mobb Deep, Fat Joe & Surprise — "Enemies (Remix)" (production coordinator)
Koch Records
2004: Royce da 5′9″ — "What I Know" from Death Is Certain (mixing)
Fourfivesix Entertainment/W.O.R.L.D Records
2004: The UN — UN Or U Out (A&R)
Terror Squad/Atlantic Records
2005: Fat Joe — All or Nothing (A&R)
Fat Joe — "Get It Poppin'" (A&R)
Awards and nominations
!
|-
|align=center|2022
|Planet Her (Deluxe)
|Grammy Award for Album of the Year
|
|
|-
References
External links
A&R people
Living people
American music critics
American record producers
American music journalists
Audio engineers
Mixing engineers
Atlantic Records artists
Hip-hop record producers
Record producers from New York (state)
Year of birth missing (living people) | Rob "Reef" Tewlow | [
"Engineering"
] | 2,151 | [
"Audio engineering",
"Audio engineers"
] |
78,001,026 | https://en.wikipedia.org/wiki/Universal%20multiport%20interferometer | In quantum mechanics, a universal multiport interferometer (or universal modal unitary) is an optical device capable of imposing general unitary transformations in the modal space of single photons or electromagnetic waves.
Classically, a mode of the electromagnetic (EM) field is defined as a normalized solution to Maxwell's equations in vacuum. In general, a mode of the EM field is represented by a vector field that varies both in space and in time. In optics, the allowed (optical) modes are restricted by the boundary conditions imposed by the system in which they exist (e.g., in an optical fiber or an optical cavity) and are thus solutions to the Helmholtz equation. For example, the Hermite-Gauss optical modes are typically used to describe beams produced in spherical mirror cavities.
To continue, a set of orthonormal modes forms an orthonormal basis which spans a modal space, or Hilbert space. The transformation from one modal basis to another is described by a rotation which, in quantum mechanics, is the action of a unitary operator (e.g., the transformation of Hermite-Gauss optical modes to Laguerre-Gauss optical modes). It has been shown that any discrete modal unitary operator can be realized using successive beam splitters and phase-shifters applied to an optical beam array. The Reck scheme provides an algorithmic approach to designing an experimental setup that uses such beam splitters and phase-shifters to implement any modal unitary transformation. The beam splitters and phase-shifters are arranged in a triangular interferometric mesh. Today, such setups are commonly referred to as universal multiport interferometers or universal modal unitaries.
The transformation of a given optical mode into another, more desired optical mode has direct applications to quantum information, optical networking, and photonic computing. The first experimental realization of the Reck scheme was in 2015 by Carolan et al. who used it to implement various linear optical (LO) quantum computing protocols such as heralded quantum logic gates and performing various boson sampling experiments.
Overview
In general, fully determining any -dimensional unitary requires specifying independent real parameters. For the simple case of transforming a two-beam array, a universal modal unitary can be implemented using a variable beam splitter and three phase-shifters. In 1994, Michael Reck and Anton Zeilinger generalized this well-known approach by proving that variable beam splitters and phase-shifters, when arranged in an interferometric mesh with arms, can be used to impose any (discrete) unitary mode transformation. Using their deterministic algorithm to decompose a given unitary into a triangular network of these two optical elements, it is possible to experimentally realize a discrete universal unitary, specifically for mode transformations. The resulting device is commonly referred to as a universal multiport interferometer.
In 2016, Clements et al. introduced a variation of Reck and Zeilinger's decomposition, again using beam splitters and phase shifters, but arranged in a symmetrically-crossing network as opposed to a triangular network. Importantly, this variation has a smaller optical depth - the longest path through the interferometric mesh - and thus experiences lower propagation losses.
The two aforementioned methods are strictly different from the universal unitary decomposition commonly used in quantum computing. That is, the universal gate, whereby any -qubit gate can be realized by a circuit of single qubit gates and CNOT gates. The classical analog of such universality is the idea that an arbitrary Boolean function can be realized using a combination of NOT gates and any one of the two-bit gates (e.g. AND, OR).
Mathematical framework
According to the Davenport rotation theorem, any three-dimensional rotation can be decomposed into three elemental rotations about non-orthogonal axes. The axes may be associated with a fixed coordinate system (i.e., extrinsic rotations) or with a rotating coordinate system (i.e., intrinsic rotations), but those associated with the first and third rotations must be in the plane orthogonal to those associated with the second rotation. If the axes associated with the first and third rotations are perpendicular to one another, the Davenport generalized rotations are called Tait-Bryan rotations. However, if the axes associated with the first and third rotations overlap, they are called Euler rotations.
Mathematically, the three composed rotations are represented by a non-commutative product of three matrices. They are non-commutative as the order in which the rotations are applied affects the resulting orientation of the subject.
The elemental rotations each occur within a two-dimensional subspace of the higher-dimensional Euclidean space. In numerical linear algebra, rotations of this type are commonly described by the Givens rotation matrix. They were introduced in the 1950s by Wallace Givens and are used to implement rotations within a plane spanned by two coordinate axes.
Unitary operators are generalizations of the rotation of Euclidean vectors, and thus one can think of constructing a discrete unitary operator in a similar manner to that described by the Davenport rotation theorem. If one can build a tunable device capable of implementing the Givens rotation to a set of optical modes , then perhaps a chain of such devices could be used to implement any unitary mode transformation . Therefore, the experimental realization of such a Givens rotation device and the proof of its functionality represents a possible method for designing a universal unitary.
Givens rotation
A Givens rotation is a well-known operation in linear algebra that performs a rotation in a two-dimensional subspace of a higher-dimensional space. Mathematically, it the Givens rotation has the following matrix representation:where denote the rows in which the rotation terms appear. The left multiplication of on another matrix results in only rows and of being affected. The effect of the Givens operation thus reduces to the transformation of two input amplitudes, and (where and are elements of the - and -th rows of , respectively), into the new amplitudes, and , as follows:The Givens rotation can be used to zero out a specific element of a vector (e.g., making ) or systematically triangularize a matrix, making it essential for linear algebra algorithms like matrix factorization and solving systems of equations.
This is the same matrix that defines the Jacobi rotation, but the choice of angle differs by a factor of approximately 2.
Experimental motivation
In 1986, Mirsalehi et al. proposed a lossless integrated-optical implementation of a Givens rotation device using diffraction from a thick electro-optic grating and phase modulators to perform the necessary operations for efficient and high-speed data processing.
The proposed device operates with two coherent, monochromatic input waves representing amplitudes and . The phase modulators adjust the relative phase of these inputs, while the diffraction grating computes the sine and cosine components. The outputs and are coherently combined to produce the desired rotation.
The input and output light signals are guided in waveguides. The use of z-cut lithium niobate waveguides ensures low-loss and high-speed operation.
A thick diffraction grating modulated by a voltage generates the sine and cosine multiplications naturally. The input wave amplitudes and are processed through the grating to produce transmitted, , and diffracted, , components.
Electro-optic phase shifters adjust the phases of the optical waves to ensure coherent addition and subtraction, corresponding to the operations required for the rotation matrix.
The final implementation achieves the desired outputs:Mirsalehi et al. proposed using such a Givens device as a building block in lattice filters and wavefront processors. With this in mind, it was already known that such interferometric meshes could perform useful operations, but it was not until nearly a decade later, when Reck et al. published their work that these meshes were shown to implement a universal unitary.
Reck and Zeilinger Scheme
Reck et al. showed that a triangular arrangement of beam splitters and phase-shifters could be systematically programmed, using a straightforward analytical approach, to implement any unitary transformation across a set of optical channels. The notation below is from the second-quantization formulation of quantum optics. In particular, the creation operator represents the addition of a photon to a specific plane wave mode .
Phase-shifters
A phase-shifter adds a phase to the state of a photon passing through it. In terms of creation operators, it performs the following transformation:
The same phase can be achieved by propagating through a material with linear refractive index and thickness , where:
Beam splitters
A beam splitter mixes two input modes and , producing two output modes and . The transformations are given by:The universal unitary for beam transformations is more commonly written in the following form:which is a combination of the modified Givens rotation matrix seen above and three phase-shifters, namely , , and . The transmittance of the beam splitter appears in the matrix as . These are the four free parameters which must be set to fully characterize the unitary matrix (as expected, ). The third phase-shifter, , represents a global offset which can usually be neglected in most practical applications, though it does play an important role when considering geometric phase.
In the notation of Reck et al., the beam transformation is written as,where the missing free parameters are accounted for in a new matrix which will be introduced below.
Algorithm
The objective is to determine the set of matrices such that:where and are the port numbers in the triangular mesh. The matrix is a modified Givens rotation matrix.
Step 1: Initial multiplication
Multiply from the right by a succession of matrices for . This is where the matrix is an -dimensional identity matrix with the elements and replaced by the corresponding beam transformation matrix elements. Hence, it represents a modified Givens rotation matrix.
By the properties of the Givens rotation matrix, and in can be chosen such that, upon multiplication with , the resulting matrix element at vanishes. Changing the index and performing another multiplication with specially chosen values of and , the resulting matrix element at vanishes. Repeating successive multiplications until the index is reached will result in the last row vanishing (expect the on-diagonal element which remains 1). Due to the unitarity of each transformation, the rightmost column will also vanish (again, expect the on-diagonal element which remains 1). This step reduces the effective dimension of to .Step 2: Recursive multiplication
Multiply the reduced matrix from the right by a succession of matrices for . Following the same thought-process as in step 1, this will result in the second-to-last row vanishing and by unitarity, the second-to-rightmost column vanishing (except for the on-diagonal element). The resulting reduced matrix is of the following form:Repeating this step in a recursive fashion until the matrix multiplication involves will result in a transformed diagonal matrix. Notice that the elements along the diagonal have modulus of unity.
Step 3: Recovering the unitary
The final step is to separate the unitary from the successive transformations. This is accomplished by multiplying the transformed diagonal matrix by another diagonal matrix whose elements are also modulus of unity such that the outcome is the identity matrix:In practice, represents a set of phase shifters that compensate for the phases appearing along the diagonal of the transformed matrix.
By the properties of the identity matrix, the product of the final transformed matrix and represents the inverse of ,
Experimental implementation
The experimental setup predicted by the Reck algorithm is described entirely by Each matrix in this product has an experimental counterpart. That is, each matrix represents the beam transformation and thus can be implemented by an individual beam splitter, and the diagonal matrix can be realized by an additional set of phase-shifters.
The maximum number of beam splitters needed for a general is . Since each beam splitter has two free parameters, that is free parameters in addition to the free parameters from . This corresponds to a total of free parameters that must be controlled, as expected.
According to Reck et al., the practical implementation of this scheme is a triangular array of beam splitters and phase-shifters. This is where each beam splitter has an associated phase-shifter at one of its input ports. In addition, phase-shifters are placed at each of the final output ports of the multiport interferometer to perform final phase corrections.
This interferometric mesh essentially contains individual interferometers that all require phase stability. This represents the main challenge to experimentally implementing the Reck scheme in free-space.
Applications
In 2015, Jacques Carolan, Jeremy O'Brien, Anthony Laing, and colleagues experimentally implemented, for the first time, the Reck scheme for the purpose of demonstrating various linear optical (LO) quantum computing protocols. Their device utilized the Reck scheme, but had two key differences:
Their device was implemented in integrated optics and thus did not rely on the free-space propagation of light between the interferometers in the mesh.
Instead of using variable transmittivity () beam splitters at each node of the interferometric mesh, they used Mach-Zehnder interferometers containing tunable phase shifters.
The consequence of the first difference is that their device did not require extremely precise or tedious phase stabilization techniques. The consequence of the second difference is that their device was entirely controlled by phase and not a combination of phase and variable transmittivity.
In particular, their reprogrammable device functioned as a universal six-port interferometer and thus a universal unitary in the modal space spanned by up to six optical modes. It consisted of 15 Mach-Zehnder interferometers and a total of 30 thermo-optic phase shifters. Their measurements were performed using a 12-single-photon detector system.
They used their device to realize a controlled-NOT quantum logic gate and performed full quantum process tomography finding a process fidelity of and an average gate fidelity of . In addition, they implemented 100 Haar random unitaries with an average fidelity of , and six-dimensional complex Hadamard matrices. Finally, they demonstrated the use of their device in performing Boson sampling with six-photon verification tests.
The implementation of the Reck scheme in this form has been highly influential in the field of optics and photonic computing. They have since been used to demonstrate quantum walks, generate entangled qutrit states, and implement the Fast Fourier transform algorithm. In addition, they have been made in ultraviolet-written silica-on-silicon chips.
See also
Unitary operator
Unitary transformation
Universal quantum gate
Givens rotation
Interferometry
References
Further reading
Reck, M., Zeilinger, A., Bernstein, H. J., & Bertani, P. (1994). Experimental Realization of Any Discrete Unitary Operator (Vol. 73, Issue 1).
Clements, W. R., Humphreys, P. C., Metcalf, B. J., Kolthammer, W. S., & Walsmley, I. A. (2016). Optimal design for universal multiport interferometers. Optica, 3(12), 1460. https://doi.org/10.1364/optica.3.001460
Barnett, S. M. (2014). Quantum Information. Oxford University Press.
Nielsen, M. A., & Chuang, I. L. (2010). Introduction to quantum mechanics. In Quantum Computation and Quantum Information: 10th Anniversary Edition (pp. 60–119). chapter 2, Cambridge: Cambridge University Press.
External links
How to build any discrete unitary operator in your laboratory (https://opg.optica.org/abstract.cfm?uri=eqec-1994-QTuC6)
Interferometers | Universal multiport interferometer | [
"Technology",
"Engineering"
] | 3,261 | [
"Interferometers",
"Measuring instruments"
] |
78,001,036 | https://en.wikipedia.org/wiki/Border%27s%20theorem | In auction theory and mechanism design, Border's theorem gives a necessary and sufficient condition for interim allocation rules (or reduced form auctions) to be implementable via an auction.
It was first proven by Kim Border in 1991, expanding on work from Steven Matthews, Eric Maskin and John Riley. A similar version with different hypotheses was proven by Border in 2007.
Preliminaries
Auctions
Auctions are a mechanism designed to allocate an indivisible good among bidders with private valuation for the good – that is, when the auctioneer has incomplete information on the bidders' true valuation and each bidder knows only their own valuation.
Formally, this uncertainty is represented by a family of probability spaces for each bidder , in which each represents a possible type (valuation) for bidder to have, denotes a σ-algebra on , and a prior and common knowledge probability distribution on , which assigns the probability that a bidder is of type . Finally, we define as the set of type profiles, and the set of profiles .
Bidders simultaneously report their valuation of the good, and an auction assigns a probability that they will receive it. In this setting, an auction is thus a function satisfying, for every type profile
where is the -th component of . Intuitively, this only means that the probability that some bidder will receive the good is no greater than 1.
Interim allocation rules (reduced form auctions)
From the point of view of each bidder , every auction induces some expected probability that they will win the good given their type, which we can compute as
where is conditional probability of other bidders having profile type given that bidder is of type . We refer to such probabilites as interim allocation rules, as they give the probability of winning the auction in the interim period: after each player knowing their own type, but before the knowing the type of other bidders.
The function defined by is often referred to as a reduced form auction. Working with reduced form auctions is often much more analytically tractable for revenue maximization.
Implementability
Taken on its own, an allocation rule is called implementable if there exists an auction such that
for every bidder and type .
Statement
Border proved two main versions of the theorem, with different restrictions on the auction environment.
i.i.d environment
The auction environment is i.i.d if the probability spaces are the same for every bidder , and types are independent. In this case, one only needs to consider symmetric auctions, and thus also becomes the same for every . Border's theorem in this setting thus states:
Proposition: An interim allocation rule is implementable by a symmetric auction if and only if for each measurable set of types , one has the inequality
Intuitively, the right-hand side represents the probability that the winner of the auction is of some type , and the left-hand side represents the probability that there exists some bidder with type . The fact that the inequality is necessary for implementability is intuitive; it being sufficient means that this inequality fully characterizes implementable auctions, and represents the strength of the theorem.
Finite sets of types
If all the sets are finite, the restriction to the i.i.d case can be dropped. In the more general environment developed above, Border thus proved:
Proposition: An interim allocation rule is implementable by an auction if and only if for each measurable sets of types , one has the inequality
The intuition of the i.i.d case remains: the right-hand side represents the probability that the winner of the auction is some bidder with type , and the left-hand side represents the probability that there exists some bidder with type . Once again, the strength of the result comes from it being sufficient to characterize implementable interim allocation rules.
Notes
References
Auction theory
Mechanism design | Border's theorem | [
"Mathematics"
] | 783 | [
"Game theory",
"Mechanism design",
"Auction theory"
] |
78,001,798 | https://en.wikipedia.org/wiki/N-Acetylputrescine | N-Acetylputrescine (NacPut), also known as monoacetylputrescine, is an endogenous metabolite of putrescine and a precursor and metabolic intermediate in the biosynthesis of γ-aminobutyric acid (GABA) from putrescine.
The metabolic pathway is specifically putrescine into N-acetylputrescine by putrescine acetyltransferase (PAT), N-acetylputrescine into N-acetyl-γ-aminobutyraldehyde (N-acetyl-GABAL or N-acetyl-GABA aldehyde) by monoamine oxidase B (MAO-B), N-acetyl-GABAL into N-acetyl-γ-aminobutyric acid (N-acetyl-GABA) by aldehyde dehydrogenase (ALDH), and N-acetyl-GABA into GABA by an unknown deacetylase enzyme. This pathway is a minor alternative pathway to the major and primary pathway in which GABA is synthesized from glutamate. There is also another alternative pathway in which putrescine is converted into GABA with γ-aminobutyraldehyde (GABAL or GABA aldehyde) as an intermediate instead. It has been estimated that about 2 to 3% of GABA is synthesized from putrescine in the mouse brain, whereas in the case of the rat brain, the amount was negligible.
In 2021, it was discovered that MAO-B does not mediate dopamine catabolism in the rodent striatum but instead participates in striatal GABA synthesis and that synthesized GABA in turn inhibits dopaminergic neurons in this brain area. It has been found that MAO-B, via the putrescine pathway, importantly mediates GABA synthesis in astrocytes in various brain areas, including in the hippocampus, cerebellum, striatum, cerebral cortex, and substantia nigra pars compacta (SNpc). These findings may warrant a rethinking of the actions of MAO-B inhibitors in the treatment of Parkinson's disease.
References
1,4-Butanediyl compounds
Acetyl compounds
Diamines
GABA analogues
Neurotransmitter precursors
Prodrugs | N-Acetylputrescine | [
"Chemistry",
"Biology"
] | 512 | [
"Biotechnology stubs",
"Prodrugs",
"Biochemistry stubs",
"Biochemistry",
"Chemicals in medicine"
] |
78,001,957 | https://en.wikipedia.org/wiki/N-Acetyl-%CE%B3-aminobutyric%20acid | N-Acetyl-γ-aminobutyric acid (N-acetyl-GABA), also known as N-acetyl-4-aminobutyric acid, is a metabolic intermediate in the biosynthesis of γ-aminobutyric acid (GABA) from putrescine. Other intermediates in this pathway include N-acetylputrescine and N-acetyl-γ-aminobutyraldehyde (N-acetyl-GABAL or N-acetyl-GABA aldehyde). Enzymes mediating the transformations in this pathway include putrescine acetyltransferase (PAT), monoamine oxidase B (MAO-B), aldehyde dehydrogenase (ALDH), and an unknown deacetylase enzyme. The pathway is a minor pathway in GABA synthesis compared to the main pathway in which GABA is synthesized from glutamate. However, the pathway has been found to have an important physiological role in the brain, for instance in the production of GABA in the striatum and resultant inhibition of dopaminergic neurons in this brain area.
References
Acetamides
GABA analogues
Gamma-Amino acids
Neurotransmitter precursors
Prodrugs | N-Acetyl-γ-aminobutyric acid | [
"Chemistry",
"Biology"
] | 275 | [
"Biotechnology stubs",
"Prodrugs",
"Biochemistry stubs",
"Biochemistry",
"Chemicals in medicine"
] |
78,002,065 | https://en.wikipedia.org/wiki/4-Acetamidobutanal | 4-Acetamidobutanal, also known as N-acetyl-γ-aminobutyraldehyde, N-acetyl-GABAL, or N-acetyl-GABA aldehyde, is a metabolic intermediate in the biosynthesis of γ-aminobutyric acid (GABA) from putrescine. Other intermediates in this pathway include N-acetylputrescine and N-acetyl-γ-aminobutyric acid (N-acetyl-GABA). Enzymes mediating the transformations in this pathway include putrescine acetyltransferase (PAT), monoamine oxidase B (MAO-B), aldehyde dehydrogenase (ALDH), and an unknown deacetylase enzyme. The pathway is a minor pathway in GABA synthesis compared to the main pathway in which GABA is synthesized from glutamate. However, the pathway has been found to have an important physiological role in the brain, for instance in the production of GABA in the striatum and resultant inhibition of dopaminergic neurons in this brain area.
References
Acetyl compounds
Aldehydes
Amines
GABA analogues
Neurotransmitter precursors
Prodrugs | 4-Acetamidobutanal | [
"Chemistry"
] | 273 | [
"Functional groups",
"Prodrugs",
"Chemicals in medicine",
"Amines",
"Bases (chemistry)"
] |
78,003,998 | https://en.wikipedia.org/wiki/Keka%20HR | Keka HR is a software company specializing in cloud-based HR management software and payroll automation.
It was founded by Vijay Yalamanchili, the current CEO, on July 21, 2014. The company is headquartered in Hyderabad, with subsidiaries in Singapore and the United States.
History
Keka HR was established in 2014 in Hyderabad, Telangana, India. In 2015, the company entered the Indian HR market and the same year, won the HYSEA Hottest Startups Award.
By 2019, Keka HR had surpassed $1 million in annual recurring revenue (ARR). During the COVID-19 pandemic in 2020, the company increased its sales sevenfold.
By 2021, Keka HR served 5,500 customers, recording an ARR of $6.5 million and managing payroll for 3.2 million employees. The company also raised $1.6 million through Recur Club.
In 2022, Keka HR secured India's largest Series A funding of $57 million from West Bridge Capital.
Keka JR specializes in providing business services in the field of HR technology, payroll automation, recruiting, leave, attendance and performance management.
Keka HR's headquarters is located in Madhapur, Hyderabad, Telangana, India, with offices in Singapore and Seattle, Washington.
Operations and Locations
Keka HR operates in the software industry, specializing in providing business services, particularly in the field of HR technology, payroll automation, recruiting, leave, attendance and performance management.
Keka's headquarters is located in Madhapur, Hyderabad, Telangana, India, with offices located in Singapore and Seattle, Washington.
References
Companies of India
Application software
Automation software | Keka HR | [
"Engineering"
] | 337 | [
"Automation software",
"Automation"
] |
78,004,264 | https://en.wikipedia.org/wiki/TON%20S180 | TON S180 (abbreviation of Tonantzintla S180) is a Seyfert galaxy located in the southern constellation of Cetus. It is located 827 million light years from Earth. The galaxy is classified as a quasi-stellar object (QSO) because of its high luminosity and is located 3.6 degrees northeast from NGC 253, and 2.8 degrees southeast from NGC 247.
Discovery and observation
TON S180 was first discovered in the year 1958 by Mexican astronomers who catalogued the object as entry number 180 under the Tonantzintla Blue Stellar Object Survey. In 1962 the object was then catalogued as PHL 912 by the Palomar-Haro-Luyten Survey. Subsequently, in 1980 and 1995, TON S180 was detected as an ultraviolet emitter by the Kiso Schmidt Camera Survey and the Extreme Ultraviolet Explorer.
Characteristics
TON S180 is categorized a narrow-line Seyfert galaxy. It has a prototype 'bare' active galactic nucleus with a total infrared luminosity of Lbol ~ 5 x1045 erg s−1, but no traces of absorption. The galaxy has a vertical soft X-ray spectrum measuring a photon index of Γ = 2.68 and a Hβ width measuring 900 km s−1. In addition, TON S180 has a short galactic column density along the line of sight, approximately NH = 1.52 x 1020 cm−2. It has an absolute magnitude of MB = -23.1 and an estimated central black hole mass of M ~ 2 x 107 MΘ. According to a spectral energy distribution presented for TON S180, it is shown more energy is emitted in the 10-100 eV band.
The host galaxy of TON S180 is a spiral galaxy of type SABa classification. The galaxy appears as a star-like object found obscured by its own circular halo. It contains a sharp and narrow iron line, as well as having a smooth soft excess unable to be produced by relativistic reflection based on observations of its X-ray spectrum.
TON S180 is known to be extremely variable compared to other Seyfert galaxies. Every few thousand seconds, its X-ray flux would show a factor of 2 variability, which, comparing to both the 0.5-2 and 2-10 keV bands, the former has a significantly high σ 2 root mean square. According to the Far Ultraviolet Spectroscopic Explorer, which acquired a high-resolution spectra for the galaxy, TON S180 shows ultraviolet absorption by five-times ionized oxygen but no hydrogen absorption, indicating its absorbing gas is currently in a high ionization state.
References
Seyfert galaxies
Quasars
Cetus
Astronomical objects discovered in 1958
087796
F00548-2238 | TON S180 | [
"Astronomy"
] | 576 | [
"Cetus",
"Constellations"
] |
78,004,330 | https://en.wikipedia.org/wiki/O%2CO%E2%80%B2-Diacetyldopamine | O,O′-Diacetyldopamine, or 3,4-O-diacetyldopamine, also known as 3,4-diacetoxyphenethylamine, is a synthetic derivative of dopamine in which both of the hydroxyl groups have been acetylated.
Description
The drug was an attempt at creating a more lipophilic analogue and prodrug of dopamine which could potentially be used medically for central nervous system indications like treatment of Parkinson's disease.
Dopamine itself is too hydrophilic to cross the blood–brain barrier and hence is peripherally selective. This, in part, prevents dopamine itself from being employed pharmaceutically for such uses. Whereas the experimental log P of dopamine is -0.98, the predicted log P (XLogP3) of O,O′-diacetyldopamine is 0.3. The optimal log P for brain permeation and central activity is about 2.1 (range 1.5–2.7).
O,O′-Diacetyldopamine proved to be inactive in animal behavioral tests. This suggests that dopamine O-acetylation alone is insufficient to allow for brain permeability. However, synthetic dopamine derivatives that were both O-acetylated and N-alkylated, with further increased lipophilicity, for instance N,N-dimethyl-O,O′-acetyldopamine (XLogP3 = 1.3), were robustly active in behavioral tests, including reversal of behavioral depression induced by the dopamine depleting agent tetrabenazine.
Other dopamine analogues and prodrugs have also been developed and studied.
See also
Neurotransmitter prodrug
O,O′-Dipivaloyldopamine
Docarpamine
O-Acetylbufotenine
References
Abandoned drugs
Acetate esters
Catecholamines
Dopamine
Dopamine agonists
Monoamine precursors
Peripherally selective drugs
Phenethylamines
Prodrugs | O,O′-Diacetyldopamine | [
"Chemistry"
] | 447 | [
"Chemicals in medicine",
"Drug safety",
"Prodrugs",
"Abandoned drugs"
] |
78,004,455 | https://en.wikipedia.org/wiki/NGC%203049 | NGC 3049 is a barred spiral galaxy located in the constellation Leo. Its velocity relative to the cosmic microwave background is 1793 ± 24 km/s, which corresponds to a Hubble distance of 26.4 ± 1.9 Mpc (∼86.1 million ly). NGC 3049 was discovered by French astronomer Édouard Stephan in 1882.
The luminosity class of NGC 3049 is I-II and it has a broad HI line. It also contains regions of ionized hydrogen and is a starburst galaxy. NGC 3049 is also a field galaxy, that is to say it does not belong to a cluster or group and is therefore gravitationally isolated. NGC 3049 is a galaxy whose core shines in the field of ultraviolet. It is listed in the Markarian catalog under the reference Mrk 710 (MK 710).
To date, 11 non-redshift measurements yield a distance of 23.136 ± 6.782 Mpc (∼75.5 million ly), which is within the Hubble distance. Note, however, that it is with the average value of independent measurements, when they exist, that the NASA/IPAC database calculates the diameter of a galaxy and that consequently the diameter of NGC 3049 could be approximately 19 .2 kpc (∼62,600 ly) if Hubble distance was used to calculate it.
See also
List of NGC objects (3001–4000)
External links
NGC 3049 at NASA/IPAC
NGC 3049 at SIMBAD
References
3049
Astronomical objects discovered in 1882
Barred spiral galaxies
Leo (constellation) | NGC 3049 | [
"Astronomy"
] | 323 | [
"Leo (constellation)",
"Constellations"
] |
78,005,062 | https://en.wikipedia.org/wiki/Electromagnetically%20enhanced%20Physical%20Vapor%20Deposition | Electromagnetically-enhanced Physical Vapor Deposition (EPVD) is coating technique developed by Paradigm Shift Technologies, Inc. which uses electromagnetic fields to improve traditional physical vapor deposition, particularly in high-stress applications like gun barrel coatings.
History
EPVD technology was developed by Paradigm Shift Technologies, Inc., a Canadian company founded in 1995. It was invented to replace the traditional chrome plating.
Thin-film deposition is the overarching technology from which PVD, CVD, ALD, EBPVD, and EPVD are derived, each employing different methods to achieve specific coating characteristics. PVD (Physical Vapor Deposition) involves the physical vaporization of material in a vacuum to form a thin film, while EBPVD (Electron Beam Physical Vapor Deposition) uses an electron beam to vaporize the source material more efficiently.
EPVD (Electro-magnetically enhanced Physical Vapor Deposition), on the other hand, enhances the standard PVD process by utilizing electromagnetic fields to guide the deposition. This allows coatings to be applied to non-line-of-sight internal surfaces, such as the interiors of tubular components, resulting in much thicker, more robust, and uniform coatings compared to traditional PVD methods. This advanced process not only improves the durability of the coating but also enables the use of these coatings in more complex geometries, making it highly advantageous in industries requiring extreme wear resistance
Process overview
EPVD involves vaporizing the coating material in vacuum and depositing it onto the substrate. Electromagnetic fields are applied to control the deposition rate and ensure uniform coating thickness, resulting in superior coating properties. In this process, the material is removed from a target made from the refractory alloy and deposited on the bore of the gun barrel in a low-pressure, inert environment.
The EPVD process generates thick coatings (50 to 300 microns) needed for gun barrels and can be adapted for small, medium, and large calibers. It applies engineered multilayer coatings using mostly metallic or ceramic materials, predominantly featuring tantalum, tungsten, and other refractory metals.
Applications
EPVD technology is mainly used in the defense industry for coating gun barrels, enhancing accuracy, durability, and lifespan under high-stress conditions.
Beyond defense, EPVD is applied in aerospace for turbine blades and engine components to improve temperature and wear resistance. The automotive industry uses it to enhance engine and transmission parts, while petrochemical, industrial machinery, and medical device sectors benefit from increased durability and biocompatibility in surgical instruments and implants.
References
Technology
Military technology
Coatings
Science and technology in Canada
Canadian inventions
Technology companies of Canada | Electromagnetically enhanced Physical Vapor Deposition | [
"Chemistry"
] | 541 | [
"Coatings"
] |
78,005,165 | https://en.wikipedia.org/wiki/NGC%203806 | NGC 3806 is an intermediate spiral galaxy located in the constellation Leo. Its velocity relative to the cosmic microwave background is 3829 ± 24 km/s, which corresponds to a Hubble distance of 56.5 ± 4.0 Mpc (∼184 million ly). NGC 3806 was discovered by Prussian astronomer Heinrich d'Arrest in 1862.
Opinions differ on the classification of NGC 3806. The NASA/IPAC and LEDA databases list it as an intermediate spiral and Professor Seligman and Wolfgang Steinicke call it a barred spiral. The luminosity class of NGC 3806 is II and it has a broad HI line.
NGC 3800 group
The galaxy NGC 3806 is part of the NGC 3800 group. This group of galaxies has at least 16 members. Other New General Catalogue galaxies in this group are NGC 3768, NGC 3790, NGC 3799, NGC 3800, NGC 3801, NGC 3802, NGC 3827 and NGC 3853. Other galaxies in the group are UGC 6631, UGC 6653, UGC 6666, UGC 6794, MCG 3-30-33 and MCG 3-30-38.
See also
List of NGC objects (3001–4000)
External links
NGC 3806 at NASA/IPAC
NGC 3806 at SIMBAD
NGC 3806 at LEDA
(FR) NGC 3806 at SEDS
References
3806
Leo (constellation)
Intermediate spiral galaxies
Astronomical objects discovered in 1862 | NGC 3806 | [
"Astronomy"
] | 304 | [
"Leo (constellation)",
"Constellations"
] |
78,005,330 | https://en.wikipedia.org/wiki/1SWASP%20J093010.78%2B533859.5 | 1SWASP J093010.78+533859.5 is a quintuple star system located in the constellation Ursa Major.
Description
Initially, two stars were discovered that were so close together that their atmospheres touched each other. Both stars take six hours to orbit each other. A second pair of stars was discovered about 13 billion miles away, as well as a fifth star located about 1.3 billion miles from the second pair. The five stars are connected by gravity and therefore do not form separate systems. No planets have yet been discovered in the system.
The star system is located approximately 138 light years from Earth, and was discovered using data from the "Super Wide Angle Search for Planets" (SuperWASP) project in the Canary Islands.
See also
V1400 Centauri
References
Star systems
Wide Angle Search for Planets | 1SWASP J093010.78+533859.5 | [
"Astronomy"
] | 175 | [
"Ursa Major",
"Wide Angle Search for Planets",
"Constellations",
"Astronomy organizations"
] |
75,000,820 | https://en.wikipedia.org/wiki/Centro%20de%20Estudios%20de%20Fisica%20del%20Cosmos%20de%20Aragon | The Centro de Estudios de Física del Cosmos de Aragón (CEFCA) is a Research institute in Teruel, Spain. Established in 2008 as a private foundation of public initiative. by the Government of Aragon. Besides research in astronomy, and leading several large astronomical surveys, CEFCA is the operator of the Astrophysical Observatory of Javalambre (OAJ, recognized as Unique Science and Technology Infrastructure by the national government). The primary research interests at CEFCA are in Stellar evolution, Time-domain astronomy and Galaxy evolution.
History
CEFCA was officially established in July 2008 with Mariano Moles Villamate as the founding director.
The founding of CEFCA is intertwined with that of the OAJ, see the history of OAJ for more.
Some key dates in CEFCA's history include:
2008: CEFCA is established.
2009: First meeting of CEFCA Steering committee (Patronato de la Fundación CEFCA) and launch of project (allowing hiring of staff).
2010: CEFCA moved to its current location (in Teruel's Plaza San Juan).
2014: OAJ was recognized as a national .
2016: Javier Cenarro Lagunas became the director.
Location
CEFCA is geographically located in the following installations within the Province of Teruel.
The CEFCA headquarters are located in the historical center of Teruel (at Plaza San Juan, number 1). In a building that was previously owned by the Teruel branch of the Bank of Spain.
The Astrophysical Observatory of Javalambre (OAJ), which is located on the "Buitre" peak of the Sierra de Javalambre.
CEFCA's main High performance computing facility (Unit for Processing and Archival of Data) is located in the Government of Aragon building of Teruel.
CEFCA's main outreach facility is GALACTICA, which is an astronomy museum as well as facilities for Amateur astronomy. It is located on the base of the Pico de Buitre (where OAJ is located on the summit) in the Arcos de las Salinas village.
Academics
CEFCA's academic activity can be classified in the following fields
Graduate program
CEFCA's graduate program is composed of multiple levels:
Summer internships:
CEFCA provides funding for M.Sc students from any Spanish university to stay in Teruel for July and August to conduct a short research project with CEFCA's research staff.
Google Summer of Code projects that are available internationally and are done remotely.
M.Sc final project: this is a one-year project conducted by M.Sc students in Spain. CEFCA's research staff propose research topics for the students of any Spanish university. The students conduct their research in their host university, but under the supervision of the CEFCA research staff.
PhD program: A number of PhD students from any university are regularly funded and trained by CEFCA for the full 4-year period of a PhD course in Spain and are based in Teruel. Previous universities that CEFCA has cooperated with for this purpose include University of Zaragoza and Complutense University of Madrid.
Astrophysics
CEFCA's astrophysics research can be categorized in the following fields; primarily using data from the Astrophysical Observatory of Javalambre (OAJ); but not limited to them.
Wide-field Astronomical surveys: design and conduction of wide-field, multi-filter astronomical surveys. This includes surveys like J-PAS (planned to be +8000 square degrees in 57 filters), J-PLUS (+3000 square degrees in data release 3 in 12 filters), Mini-HAWKs (on-going), J-ALFIN (on-going), MUDEHaR (on-going) and North-PHASE (on-going).
Astroinformatics: Including the data processing, archiving and analysis of the large volume the wide field imaging data that is produced by the observatory. The OAJ has a dedicated Department for Processing and Archival of Data (DPAD) for this purpose which contains staff researchers, technical astronomers and engineers.
Time-domain astronomy: imaging large portions of the sky in various times allows the study of asteroids in the solar system (which move in the sky), variable stars within the Milky Way (which change brightness), or supernova in other galaxies
Stellar and galaxy evolution: the very wide field of view, and the many filters of the surveys conducted at OAJ allow accurate measurements of thousands of stars and galaxies in each exposure.
See also
J-PAS
Astrophysical Observatory of Javalambre
Instituto de Astrofísica de Canarias
Instituto de Astrofísica de Andalucía
References
Astronomy in Spain
Astrophysics research institutes
Research institutes in Spain
Astronomy data and publications
Science and technology in Spain
Buildings and structures in Teruel
Astrophysics
Astronomy organizations
Teruel
Astronomy institutes and departments | Centro de Estudios de Fisica del Cosmos de Aragon | [
"Physics",
"Astronomy"
] | 1,001 | [
"Astronomy institutes and departments",
"Works about astronomy",
"Astronomy organizations",
"Astrophysics",
"Astrophysics research institutes",
"Astronomy data and publications",
"Astronomical sub-disciplines"
] |
75,000,890 | https://en.wikipedia.org/wiki/List%20of%20inventoried%20conifers%20in%20Canada | Canada's national forest inventory includes many native conifer species. All except the larches are evergreens. Most are in the pine family, except for yews (in the yew family) and junipers, Alaska cedars and thuja cedars (in the cypress family).
Softwood from North American conifers has a variety of commercial uses. The sturdier timber is milled for plywood, wood veneer and construction framing, including structural support beams and studs. Logs can be fashioned into posts, poles and railroad ties. Less sturdy timber is often ground and processed into pulpwood, principally for papermaking. Resins from sap yield wood tar, turpentine or other terpenes. Some resins and other tree products contain dangerous toxins (not generally listed below).
Key
Provinces and territories (see the Distribution column): AB Alberta, BC British Columbia, MB Manitoba, NB New Brunswick, NL Newfoundland and Labrador, NS Nova Scotia, NT Northwest Territories, NU Nunavut, ON Ontario, PE Prince Edward Island, QC Quebec, SK Saskatchewan, YT Yukon
Conifers
Genera
See also
List of gymnosperm families
List of inventoried conifers in the United States
List of inventoried hardwoods in the United States
Notes
Citations
References
See their terms-of-use license.
Conifers
Forests of Canada
Inventoried conifers in Canada
Taxonomic lists (species) | List of inventoried conifers in Canada | [
"Biology"
] | 295 | [
"Lists of biota",
"Lists of plants",
"Plants"
] |
75,001,138 | https://en.wikipedia.org/wiki/List%20of%20motmots | Motmots are birds in the family Momotidae in the order Coraciiformes. There are currently 14 extant species of motmots recognised by the International Ornithologists' Union.
Conventions
Conservation status codes listed follow the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Range maps are provided wherever possible; if a range map is not available, a description of the motmot's range is provided. Ranges are based on the IOC World Bird List for that species unless otherwise noted. Population estimates are of the number of mature individuals and are taken from the IUCN Red List.
This list follows the taxonomic treatment (designation and order of species) and nomenclature (scientific and common names) of version 13.2 of the IOC World Bird List. Where the taxonomy proposed by the IOC World Bird List conflicts with the taxonomy followed by the IUCN or the 2023 edition of The Clements Checklist of Birds of the World, the disagreement is noted next to the species's common name (for nomenclatural disagreements) or scientific name (for taxonomic disagreements).
Classification
The International Ornithologists' Union (IOU) recognises 14 species of motmots in six genera. This list does not include hybrid species, extinct prehistoric species, or putative species not yet accepted by the IOU.
Family Momotidae
Genus Hylomanes: one species
Genus Aspatha: one species
Genus Momotus: seven species
Genus Baryphthengus: two species
Genus Electron: two species
Genus Eumomota: one species
Motmots
Notes
References
Lists of animals
Lists of birds
Momotidae | List of motmots | [
"Biology"
] | 334 | [
"Lists of biota",
"Lists of animals",
"Animals"
] |
75,001,970 | https://en.wikipedia.org/wiki/Catherine%20G%20Galbraith | Catherine G Galbraith is an American scientist who is an associate professor of Biomedical Engineering at OHSU and Discovery Engine Investigator at Knight Cancer Institute, known for her work in cell mobility and cell migration as well as super-resolution microscopy. Together with James Galbraith, she heads the Galbraith Lab.
Education
Galbraith studied Bioengineering at the University of Pennsylvania in Philadelphia, PA, USA. After receiving her BSc in 1985, she attended a Master's program in Bioengineering, which she finished in 1987. Subsequently, Galbraith earned her Ph.D. in Bioengineering in 1995 at University of California, San Diego, CA, USA, advised by Prof Dr Shu Chien.
Career and research
For her postgraduate work between 1995 and 2000, Galbraith worked as a postdoctoral researcher with Prof Dr Michael Sheetz at Duke University in Durham, NC, USA, focusing primarily on cell mobility and migration.
Between 2000 and 2013, Galbraith worked at the National Institutes of Health, Bethesda, MD, continuing her work on cell mobility and migration. First as a Research Fellow (2000-2005) and an Independent Senior Researcher (2005-2010) at the National Institute of Dental and Craniofacial Research (NIDCR) and finally as a scientist (2010-2013) at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).
Between 2010 and 2012, Galbraith was also, for the first time, a visiting scientist at Howard Hughes Medical Institute's Janelia Research Campus.
Collaborations with scientists at Janelia, in particular Eric Betzig and Harald Hess, resulted, amongst others, in key papers that helped to establish the localization-based super-resolution microscopy technique Photoactivated localization microscopy (PALM). Betzig received the Nobel Prize for PALM in 2014.
Since 2013, Galbraith has been an Associate Professor of Biomedical Engineering at OHSU and Discovery Engine Investigator at Knight Cancer Institute.
Together with her husband, James Galbraith, Galbraith uses multidisciplinary approaches and advanced microscopy techniques to explore the mechanisms behind cellular decision-making in a variety of processes, including motility, synaptogenesis, and metastasis.
Since 2019, Galbraith has also again been a visiting scientist at Howard Hughes Medical Institute's Janelia Research Campus.
Galbraith is a well-known scientist in the field who is frequently invited to speak at conferences, seminars, and workshops.
Awards and honours
1997 - Biomedical Engineering Society -- Young Investigator of the Year
2014 - ASCB/ NIGMS Life Magnified Dulles Airport Exhibit
2014 - Cover of Nature Publishing Special Issue for Super-Resolution Nobel Prize
2021 - H1 Connects (formerly Faculty Opinions) - Faculty Member of the Year, Biological Physics
2022 W. M. Keck Foundation Award
References
Living people
Microscopists
University of Pennsylvania alumni
University of California, San Diego alumni
American women scientists
21st-century American women scientists
Year of birth missing (living people)
Oregon Health & Science University faculty | Catherine G Galbraith | [
"Chemistry"
] | 628 | [
"Microscopists",
"Microscopy"
] |
75,002,510 | https://en.wikipedia.org/wiki/Fractional%20Chern%20insulator | Fractional Chern insulators (FCIs) are lattice generalizations of the fractional quantum Hall effect that have been studied theoretically since 1993 and have been studied more intensely since early 2010.
They were first predicted to exist in topological flat bands carrying Chern numbers. They can appear in topologically non-trivial band structures even in the absence of the large magnetic fields needed for the fractional quantum Hall effect. In principle, they can also occur in partially filled bands with trivial band structures if the inter-electron interaction is unusual. They promise physical realizations at lower magnetic fields, higher temperatures, and with shorter characteristic length scales compared to their continuum counterparts.
FCIs were initially studied by adding electron-electron interactions to a fractionally filled Chern insulator, in one-body models where the Chern band is quasi-flat,
at zero magnetic field. The FCIs exhibit a fractional quantized Hall conductance.
Prior work and experiments with finite magnetic fields
In works predating the theoretical studies of FCIs, the analogue of the Laughlin state was demonstrated in Hofstadter-type models. The essential features of the topology of single-particle states in such models still stems from the presence of a magnetic field. Nevertheless, it was shown that in the presence of a lattice, fractional quantum Hall states can retain their topological character, in the form of fractional Chern numbers. Chern Insulators - single-particle states exhibiting an integer anomalous quantized Hall effect at zero field - have been theoretically proposed.
Fractionally filling such states, in the presence of repulsive interactions, can lead to the zero-field Fractional Chern Insulator. These FCIs are sometimes not connected to the Fractional Quantum Hall Effect in Landau Levels. This is the case in bands with Chern number ,
and are therefore a new type of states inherent to such lattice models. They have been explored with respect to their quasi-charge excitations, non-Abelian states and the physics of twist defects,
which may be conceptually interesting for topological quantum computing.
Experimentally, Chern insulators have been realized without a magnetic field.
FCIs have been claimed to be realized experimentally in van der Waals heterostructures, but with an external magnetic field of order and, more recently, FCIs in a band have been claimed to be observed in twisted bilayer graphene close to the magic angle, yet again requiring a magnetic field, of order 5 T in order to "smoothen" out the Berry curvature of the bands.
These states have been called FCIs due to their link to lattice physics -- either in Hofstadter bands or in the moiré structure, but still required nonzero-magnetic field for their stabilization.
Zero field fractional Chern insulators
The prerequisite of zero field fractional Chern insulator is magnetism. The best way to have magnetism is to have exchange interaction that simultaneously polarize the spin. This phenomenon in twisted MoTe2 in both integer and fractional states was first observed by a University of Washington group.
In 2023 a series of groups have reported FCIs at zero magnetic field
in twisted samples. The University of Washington group first identified fractional Chern number of , and state with trion emission sensing. This is followed by the Cornell group who performed thermodynamic measurement on and state. These samples, where the moiré bands are valley-spin locked, undergo a spin-polarization transition which gives rise to a Chern insulator state at integer filling of the moiré bands. Upon fractional filling at and , a gapped state develops with a fractional slope in the Streda formula, a hallmark of an FCI. These fractional states are identical to the predicted zero magnetic field FCIs. After the optical sensing measurement, University of Washington group first reported transport `smoking-gun` evidence of fractional quantum anomalous Hall effect that should be exhibited by a zero-field fractional Chern insulator at , and . They also identified a possible composite Fermi liquid at that mimics the half filled Landau level for 2D electron gas. The and states are also partially repeated by the Shanghai group, while the quantization is not as good.
The full matching of FCI physics in , using the single particle model proposed in, to experiments still holds intriguing and unresolved mysteries. These were only partially theoretically addressed,
where the issues of model parameters, sample magnetization, and the appearance of some FCI states (at filling and ) but the absence of others (so far at filling at ) are partially addressed.
References
Correlated electrons
Quantum phases | Fractional Chern insulator | [
"Physics",
"Chemistry",
"Materials_science"
] | 949 | [
"Quantum phases",
"Phases of matter",
"Quantum mechanics",
"Condensed matter physics",
"Correlated electrons",
"Matter"
] |
75,003,317 | https://en.wikipedia.org/wiki/Neighborhood%20effect%20averaging%20problem | The neighborhood effect averaging problem or NEAP delves into the challenges associated with understanding the influence of aggregating neighborhood-level phenomena on individuals when mobility-dependent exposures influence the phenomena. The problem confounds the neighbourhood effect, which suggests that a person's neighborhood impacts their individual characteristics, such as health. It relates to the boundary problem, in that delineated neighborhoods used for analysis may not fully account for an individual's activity space if the borders are permeable, and individual mobility crosses the boundaries. The term was first coined by Mei-Po Kwan in the peer-reviewed journal "International Journal of Environmental Research and Public Health" in 2018.
Background
Mei-Po Kwan, a prominent scholar in human geography, highlighted the importance of accounting for spatial processes and interactions within neighborhoods in a 2018 paper. She argued that the analysis's neighborhood effect averaging problem arises from disregarding spatial dependence and spatial heterogeneity, and is credited with the discovery of the NEAP. In studying human geography, understanding the relationship between individual-level attributes and the effects of the neighborhood in which individuals reside is crucial. However, a significant issue arises due to the potential mismatch between the scale at which data is collected (individual level) and the scale at which analysis is conducted (neighborhood level). Individual-level data often provide detailed information about individuals, including socioeconomic status, education level, or health conditions. On the other hand, neighborhood-level data offers a broader perspective on specific areas, encompassing factors like average income, crime rates, or access to amenities.
The neighborhood effect averaging problem emerges as researchers attempt to integrate the disparate data scales of individuals and neighborhoods. The common approach involves aggregating individual-level data to the neighborhood level by calculating summary statistics such as means or proportions for each neighborhood. However, this oversimplifies the analysis by assuming that individuals within the neighborhood all have activity spaces and space-time paths within the neighborhood's borders. Studies applying the neighborhood effect fail to capture the individual's real neighborhood by failing to consider mobility. A person's mobility may amplify or attenuate environmental factors in their neighborhood.
Addressing the NEAP
To address this problem, Kwan proposed utilizing spatial statistical techniques to consider individuals neighborhood contexts at different temporal scales throughout their life. By incorporating these methods, researchers can model and analyze the spatial relationships between individuals and their neighborhoods. Factors such as proximity, spatial autocorrelation, and the influence of neighboring areas can be considered, providing a more accurate understanding of the complex dynamics between individuals and their environment.
Implications and Significance
Spatial anlysis
By acknowledging and tackling the neighborhood effect averaging problem, researchers can better understand how individual characteristics interact with neighborhood contexts to shape various outcomes, such as health outcomes, educational attainment, or social behavior. This approach advances urban and regional studies knowledge, providing insights into the intricate interplay between individuals and their surrounding environment. Failure to account for the NEAP may lead to erroneous findings.
Policy
The NEAP suggests that simply improving neighborhood conditions may not improve an individual's experience. By increasing cross-neighborhood transit and interactions between disadvantaged and advantaged neighborhoods, it may be possible to improve individual outcomes like health.
See also
References
Bias
Geographic information systems
Problems in spatial analysis | Neighborhood effect averaging problem | [
"Technology"
] | 665 | [
"Information systems",
"Geographic information systems"
] |
75,003,549 | https://en.wikipedia.org/wiki/Ballmer%20Peak | The Ballmer Peak is a humorous concept invented by Randall Munroe in the xkcd webcomic, claiming that a programmer who is appropriately intoxicated can achieve a high level of productivity. The concept loosely tied to former Microsoft CEO, Steve Ballmer, and is likely a play on Balmer series of hydrogen spectral lines named for the scientist Johann Balmer.
A San Francisco organization, Originate, has organized a “Ballmer Peak-A-Thon”, an open bar event where people were given “5 hours to find the elusive Ballmer peak, and build the best worst business possible.”
There is no scientific basis for the Ballmer Peak, though researchers have studied adjacent topics, such as the impact of inebriation on problem solving. In addition, the Ballmer Peak has been the subject of satirical academic studies, including a 2024 paper presented at SIGBOVIK, a satirical computer science conference organized by Carnegie Mellon students, which caught broader attention in the programming community. That study, which tested blood alcohol levels of only one male subject tackling competitive computer programming questions, found no evidence of a sudden “peak” of programming ability but did generally find that speed of solving the challenges increased with some alcohol consumption before a rapid decline.
By the time of Ballmer’s 2013 announcement of his retirement from Microsoft, the concept of the “Ballmer Peak” was entrenched enough that media joked that the actual Ballmer Peak was the resulting jump in stock price.
References
Computer jargon
Computer humour | Ballmer Peak | [
"Technology"
] | 308 | [
"Natural language and computing",
"Computer jargon",
"Computing terminology"
] |
75,004,059 | https://en.wikipedia.org/wiki/Susana%20F.%20Huelga | Susana F. Huelga is a Spanish physicist, and Professor at the Institute of Theoretical Physics of Ulm University.
She is notable for her contributions to the field of quantum information theory. These include quantum metrology in the presence of Markovian and non-Markovian environments, the theory of open quantum systems, numerical methods for their description in the presence of structured environments, the characterization, quantification and detection of non-Markovianity and fundamental contributions to quantum effects in biological systems.
Education
She obtained her MSc in 1990 and her Doctorate in 1995 in physics from the Universidad de Oviedo, where she worked with Miguel Ferrero and Emilio Santos. Her thesis, Optical experiments for the study of fundamental quantum properties consisted of two parts, each proposing an optical experiment. The first part is a proposal for an experiment to test "Bell's inequality capable of closing the existing exits in the atomic cascade experiments already carried out". The second part is a proposal for the contrast of the Leggett–Garg inequality in an experiment.
Career
After finishing her doctorate she spent a postdoc at the Clarendon Laboratory of Oxford University 1996 - 1997 and held a position as Profesor Titular at Universidad de Oviedo. She joined the Faculty of the Department of Physics, Astronomy and Mathematics of the University of Hertfordshire as a Lecturer in 2000 and Reader in 2008. In October 2009 she accepted a Professorship at the Institute of Theoretical Physics of the Universität Ulm where she is still working.
Personal
She is married to physicist Martin Bodo Plenio.
References
External links
at the Institute of Theoretical Physics of Ulm University
Spanish physicists
Living people
21st-century women physicists
Quantum physicists
Year of birth missing (living people) | Susana F. Huelga | [
"Physics"
] | 351 | [
"Quantum physicists",
"Quantum mechanics"
] |
75,006,028 | https://en.wikipedia.org/wiki/%C5%8Cyamazaki%20Tile%20Kiln%20Site | The is an archaeological site with the ruins of an early Heian period kiln, located in the town of Ōyamazaki, Otokuni District, Kyoto Prefecture in the Kinai region of Japan. It was designated a National Historic Site of Japan in 2006.
Overview
roof tiles made of fired clay were introduced to Japan from Baekche during the 6th century along with Buddhism. During the 570s under the reign of Emperor Bidatsu, the king of Baekche sent six people to Japan skilled in various aspects of Buddhism, including a temple architect. Initially, tiled roofs were a sign of great wealth and prestige, and used for temple and government buildings. The material had the advantages of great strength and durability, and could also be made at locations around the country wherever clay was available.
The Ōyamazaki Tile Kiln was located in the southwestern tip of Kyoto Prefecture, at a strategic point for water and land transportation. Its existence was discovered during the construction of a residential are. The kiln was in operation during the early Heian period and fired roof tiles for the palaces and other governmental structures of Heian-kyō. At that time, many tile kilns around Heian-kyō produced large quantities of roof tiles to support the construction of the new capital of Japan, and this tile kiln was one of those government-run tile kilns. During archaeological excavations conducted in 2006, six flat kilns and numerous pits were confirmed, and subsequent excavations found six more kilns.Groups A and B consist of five kilns each, and group C consists of two kilns. Groups A and B are located in an “L” shape, and groups A and C are located in a straight line. The kilns were spaced approximately 6 meters apart. Each kiln was divided into a combustion chamber for burning firewood and a firing chamber for baking tiles, and in front of the combustion chamber was a vestibule that served as a workshop. In the front, there was a field of ash where ashes from firing and failed roof tiles were discarded. The scale of all kilns is unified and standardized to ensure a constant production volume. It took around five days to produce the roof tiles, after which the kiln needed repairs. The reason for the uniform arrangement of kilns is thought to have been to ensure seamless production by firing tiles and repairing kilns in groups.The Ōyamazaki kilns produced round and flat roof tiles with lotus and arabesque patterns for decorating the eaves, flat tiles for the ridgeline and Onigawara tiles for the ridge ends. .To the northwest of the tile kiln ruins is the temple of Yamazaki Shoten (Kannon-ji), a scenic spot with views to the east, northeast, and southwest, overlooking the ruins of Nagaoka-kyō, the Yodo River, and Otokoyama.
The remains have been backfilled for protection, but the area has been developed as a park, and reconstruction of kilns are displayed. The site is about 15 minutes walk from Yamazaki Station on the JR West Tokaido Main Line.
See also
List of Historic Sites of Japan (Kyoto)
References
External links
Ōyamazaki Town home page
Historic Sites of Japan
History of Kyoto Prefecture
Yamashiro Province
Heian period
Japanese pottery kiln sites | Ōyamazaki Tile Kiln Site | [
"Chemistry",
"Engineering"
] | 689 | [
"Kilns",
"Japanese pottery kiln sites"
] |
75,007,389 | https://en.wikipedia.org/wiki/Hayaagari%20Tile%20Kiln%20Site | The is an archaeological site with the ruins of a Nara period kiln, located in the Udo neighborhood of the city of Uji, Kyoto Prefecture in the Kinai region of Japan. It was designated a National Historic Site of Japan in 1986.
Overview
roof tiles made of fired clay were introduced to Japan from Baekche during the 6th century along with Buddhism. During the 570s under the reign of Emperor Bidatsu, the king of Baekche sent six people to Japan skilled in various aspects of Buddhism, including a temple architect. Initially, tiled roofs were a sign of great wealth and prestige, and used for temple and government buildings. The material had the advantages of great strength and durability, and could also be made at locations around the country wherever clay was available.
The Hayaagari Tile Kiln was located approximately northeast of Uji Bridge in the middle reaches of the Uji River in southern Kyoto Prefecture, on the southern slope of a hill that extends from east-to-west. The remains were found during the development of a housing complex and consist of the remains of four kilns, a workshop, and an ash field. The archaeological excavation conducted in 1982 found that Goguryeo-style eaves tiles at this site are identical to those found at the ruins of Toyuraji in Asuka, Nara, some away. Four noborigama-style climbing kilns remain, spaced approximately eight meters apart, and the excavated artifacts include roof tiles, Sue ware and Haji ware pottery, inkstones, and other earthenware products. It is believed that operations began and ended around the middle of the 7th century.
The remains have been backfilled for protection, but the area has been developed as a park. The site is about a 20-minute walk from Mimurodo Station on the Keihan Electric Railway Uji Line.
See also
List of Historic Sites of Japan (Kyoto)
References
External links
Uji city home page
Historic Sites of Japan
History of Kyoto Prefecture
Yamashiro Province
Uji, Kyoto
Nara period
Japanese pottery kiln sites
Yayoi period ruins | Hayaagari Tile Kiln Site | [
"Chemistry",
"Engineering"
] | 429 | [
"Kilns",
"Japanese pottery kiln sites"
] |
75,010,052 | https://en.wikipedia.org/wiki/4B-MAR | 4'-Bromo-4-methylaminorex (4B-MAR, 4'-Br-4-MAR) is a designer drug from the substituted aminorex family, first definitively identified in Austria in January 2022. Its pharmacological activity has not been reported, but it is believed to have stimulant effects.
See also
2C-B-aminorex
2F-MAR
4C-MAR
4,4'-DMAR
4'-Fluoro-4-methylaminorex
4-Methylaminorex
MDMAR
3-Bromomethylphenidate
4-Bromoamphetamine
4-Bromomethcathinone
RTI-51
References
Aminorexes
4-Bromophenyl compounds
Designer drugs | 4B-MAR | [
"Chemistry"
] | 163 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
75,011,465 | https://en.wikipedia.org/wiki/Tremella%20anaptychiae | Tremella anaptychiae is a species of lichenicolous (lichen-dwelling) fungus in the family Tremellaceae. It was first reported in the literature in 1996 by mycologist Paul Diederich, who did not formally describe it as a new species due to the paucity of material. Additional material was collected in later years, and it was finally described in 2017 by Juan Carlos Zamora and Diederich. The fungus is known to occur in Italy, Macedonia, Spain (including the Canary Islands), and Sweden. It is confined to the host lichen Anaptychia ciliaris, which has a largely palearctic distribution.
Description
Tremella anaptychiae produces basidiomata that are typically more or less spherical in shape, becoming slightly tuberculate as they age. These are characterized by a waxy-gelatinous texture and can exhibit a variety of colours, ranging from cream to pinkish, brownish, or even blackish, with rare instances of greenish shades. Typically measuring 0.2–2 mm in diameter, they grow on the thallus of their host, often encompassing the and, less frequently, on the margin of .
The internal context hyphae and the hyphae below the basidia are slender and thick-walled, typically ranging from 3–5.5 μm in diameter. These hyphae do not have clamps but may sometimes show small spur-like swellings. Abundant haustorial branches are present, with the mother cell being roughly spherical to broadly ellipsoid. The hymenium is well-developed, either clear or subtly brownish, and contains numerous probasidia. The basidia, when mature, are two-celled, stalked, and thick-walled, often displaying longitudinal or oblique septa. They produce basidiospores that are somewhat spherical, sometimes broadly ellipsoid, and germinate to form ballistoconidia and blastic conidia.
Additionally, Tremella anaptychiae may sometimes produce asteroconidia, which have a unique four-armed structure. These asteroconidia are about 10–15 μm in diameter, with individual arms ranging from 3.5–8 μm in length. In some basidiomata, where basidia are sparse, these conidiogenous cells can be particularly numerous.
References
anaptychiae
Fungi of Europe
Fungi of the Canary Islands
Fungi described in 2017
Lichenicolous fungi
Taxa named by Paul Diederich
Fungus species | Tremella anaptychiae | [
"Biology"
] | 522 | [
"Fungi",
"Fungus species"
] |
75,013,235 | https://en.wikipedia.org/wiki/Lysobisphosphatidic%20acid | Lysobisphosphatidic acid (LBPA) (also known as bis(monoacylglycero)phosphate (BMP)) is a phospholipid that is found in the membranes of late endosomes and lysosomes of eukaryotic cells.
Phosphatidylglycerol is a precursor and structural isomer of LBPA. LBPA's stereochemistry is atypical among glycerophospholipids and influences its function within the LE/LY (late endosome/lysosome) system.
LBPA makes up 15–20% of all LE/LY phospholipids and is not found in other subcellular membranes. LBPA is primarily found within the inner LE/LY membranes where they play a role in their structure and trafficking processes. In particular, an interaction between NPC2 and LBPA is necessary for intracellular cholesterol trafficking.
See also
Lysophosphatidic acid
Niemann-Pick Type C
References
Phospholipids
Membrane biology | Lysobisphosphatidic acid | [
"Chemistry"
] | 231 | [
"Signal transduction",
"Membrane biology",
"Phospholipids",
"Molecular biology"
] |
75,014,187 | https://en.wikipedia.org/wiki/Arabic%20geomancy | Arabic geomancy is a type of geomantic divination which involves interpreting a series of figures formed by a randomized process that involves recursion, followed by analyzing them, often augmented with astrological interpretations. Geomancy was also thought by figures such as Richard II to be a greater discipline that included philosophy, science, and alchemic elements.
History
The word "geomancy", from Late Greek *γεωμαντεία *geōmanteía translates literally to "earth divination"; it is a calque translation of the Arabic term ‛ilm al-raml, or the "science of the sand". Earlier Greek renditions of this word borrowed the Arabic word raml ("sand") directly, rendering it as rhamplion or rabolion. Other Arabic names for geomancy include khatt al-raml and darb al-raml.
The original names of the figures in Middle Eastern geomancy were traditionally given in Arabic, excluding a Persian origin. The reference in Hermetic texts to the mythical Ṭumṭum al-Hindi potentially points to an Indian origin, although Stephen Skinner thinks this unlikely. Having an Arabic origin is most likely, since the expansive trade-routes of Arabian merchants would facilitate the exchange of culture and knowledge.
European scholars and universities began to translate Arabic texts and treatises in the early Middle Ages, including those on geomancy. Isidore of Seville ( 560 – 636) lists geomancy with other methods of divination – including pyromancy, hydromancy, aeromancy, and necromancy – without describing its application or methods. It could be that Isidore of Seville was listing methods of elemental scrying more than what is commonly known as geomancy. The poem Experimentarius attributed to Bernardus Silvestris, who wrote in the middle of the 12th century, was a verse translation of a work on astrological geomancy. One of the first discourses on geomancy translated into Latin was the Ars Geomantiae of Hugh of Santalla ( early 12th century). By this point, geomancy must have been an established divination system in Arabic-speaking areas of Africa and the Middle East.
Other translators, such as Gerard of Cremona ( 1114 – 1187), also produced new translations on geomancy that incorporated astrological elements and techniques that were, up until this point, ignored. From this point on, more European scholars studied and applied geomancy, writing many treatises in the process. Henry Cornelius Agrippa (1486–1535), Christopher Cattan (La Géomancie du Seigneur Christofe de Cattan (1558)), and John Heydon (1629 – 1667) produced oft-cited and well-studied treatises on geomancy, along with other philosophers, occultists, and theologians until the 17th century, when interest in occultism and divination began to dwindle due to the rise of the Scientific Revolution and the Age of Reason.
Geomancy underwent a revival in the 19th century, when renewed interest in the occult arose due to the works of Robert Thomas Cross (1850–1923) and of Edward Bulwer-Lytton (1803–1873). Franz Hartmann published his text, The Principles of Astrological Geomancy,
(English translation: 1889) which spurred new interest in the divination system. Based on this and a few older texts, the Hermetic Order of the Golden Dawn (founded in 1887) began the task of recollecting knowledge on geomancy along with other occult subjects, with them, Aleister Crowley (1875–1947) published his works that integrated various occult systems of knowledge. However, due to the short time the members of the Golden Dawn desired to learn, practice, and teach the old occult arts, many elaborate systems of divination and ritual had to be compressed, losing much in the process. In effect, they had reduced geomancy from a complex art of interpretation and skill in recognizing patterns to looking up predefined answers based on pairs of figures.
Like other systems of divination, geomancy has mythological associations. According to one Arabic Hermetic text, Idris (or Hermes Trismegistus) witnessed the angel Jibril in a dream. Idris asked for enlightenment, and Jibril proceeded to draw a geomantic figure. Upon being asked what he was doing, Jibril instructed Idris in the geomantic arts. Keeping this secret, he sought out Ṭumṭum al-Hindi, an Indian king, who then wrote a book on geomancy. This book was passed down through clandestine circles into the hands of Khalaf al-Barbarĩ, who traveled to Medina and was converted to Islam by Muhammad. Saying he knew a divinatory art, he explained that pre-Islamic prophets knew geomancy, and that by learning geomancy, one may "know all that the prophet knew".
Another mythological story for the origin of geomancy also involves Idris.<ref>Maupoil, Bernard. "Contribution à létude de l'origine musulmane de la géomancie dans le Bas-Dahomey." Journal de la sociéte des africanistes", volume 13, pp. 17–8.</ref> After praying to God that He give Idris easily a means to earn his living, Idris rested one day, bored and without work, and began to draw figures idly in the sand. As he did so, a stranger appeared before him and questioned what he was doing. Idris replied that he was simply entertaining himself, but the stranger replied that he was doing a very serious act. Idris became incredulous and tried to deny this, but the stranger explained the significance of the meaning of the figure Idris drew. He then commanded Idris to draw another figure, and upon doing so the stranger explained the meaning and significance of that figure.
The pair continued this until Idris had discovered and understood the sixteen figures. The stranger then taught Idris how to form the figures in a regular manner and what the results meant, teaching him how to know things that could not be known with just the physical senses. After testing Idris' newfound knowledge and skill of geomancy, and revealing himself to be the angel Jibril in the process, the stranger disappeared. Idris, thankful to God and His messenger that he had learned this art, never revealed the art to anyone. Before he was risen to God, he wrote a book describing the art as Jibril had taught him, and from his successors.
Other tablets and records from antiquity identify Idris with the prophets Daniel or with Enoch. This was done in order to give geomancy a legitimate standing as a gift and skill from God, especially since one of the prophets had practiced it. However, those who argued against geomancy, such as Ibn Khaldun in his Muqaddima (1377), countered that it was a pre-Islamic system of knowledge, and that all such epistemologies were rendered obsolete with the revelation of the Qur'an.
Throughout the evolution and migration of geomancy, various tales and plays incorporated aspects of the art into their stories. In one story in One Thousand and One Nights, both the African Magician and his brother use geomancy to find Aladdin in order to do him harm. Geomancy's first mention in print came in William Langland's Piers Plowman where it is unfavorably compared to the level of expertise a person needs for astronomy ("gemensye [geomesye] is gynful of speche"). In 1386 Chaucer used the "Parson's Tale" to poke fun at geomancy in Canterbury Tales: "What say we of them that believe in divynailes as …geomancie…". Shakespeare and Ben Jonson were also known to use geomancy for comic relief. Dante Alighieri's Divine Comedy (early 14th century) makes a passing reference to geomancy. In the first two stanzas of Canto XIX in the Purgatorio,
Generating geomantic charts
Geomancy requires the geomancer to create sixteen lines of points or marks without counting, creating sixteen random numbers. Without taking note of the number of points made, the geomancer provides the seemingly random mechanism needed for most forms of divination. Once the lines are produced, the geomancer marks off the points two by two until either one or two points remain in the line; mathematically, this is the same as producing two dots if the number is even or one dot if the number is odd. Taking these leftover points in groups of four, they form the first four geomantic figures, and form the basis for the generation of the remaining figures. Once this is done, the "inspired" portion of the geomantic reading is done; what remains is algorithmic calculation.
Traditionally, geomancy requires a surface of sand and the hands or a stick, but can be done equally well with a wax tablet and stylus or a pen and paper; ritualized objects may or may not be desired for use in divination. Often, when drawing marks or figures, geomancers will proceed from right to left as a tradition from geomancy's Arabic origins, although this is by no means mandatory. Modern methods of geomancy include, in addition to the traditional ways, computerized random number generators or thrown objects; other methods including counting the eyes on potatoes. Some practitioners use specialized cards, with each card representing a single geomantic figure; in this case, only four cards are drawn after shuffling. Specialized machines have also been used to generate full geomantic charts.
The figures are entered into a specialized table, known as the shield chart, which illustrates the recursive processes reminiscent of the Cantor set that form the figures. The first four figures are called the matres, or Mothers, and form the basis for the rest of the figures in the chart; they occupy the first four houses in the upper right-hand corner such that the first Mother is to the far right, the second Mother is to her left, and so on (continuing the right-to-left tradition).
The next four figures, the filiae, or Daughters, are formed by rearranging the lines used in the Mothers: the first Daughter is formed by taking the first line from the first, second, third, and fourth Mothers in order and rearranging them to be the first Daughter's first, second, third, and fourth lines, respectively. The process is done similarly for the second Daughter using the second line from the Mothers, and so on. The Daughters are placed in the next four houses in order on the same row as the Mothers.
After the eight matres and filiae are formed, the four nepotes (or Nieces) are formed by adding those pairs of figures that rest above the houses of the respective Niece. Therefore, the first and second Mothers add to form the first Niece, the third and fourth Mothers add to form the second Niece, and so on. Here, addition involves summing the points in the respective lines of the parents: if the sum is an even number, then the resulting figure's line will have two points, and if the sum is odd then the line will have one point. Conceptually, this is the same procedure in mathematical logic as the exclusive or, where a line with two points is used instead of "false" and a line with one point instead of "true".
From the four nepotes, the two testes (or Witnesses) are formed in the same manner as the nepotes: the first and second Nieces form the Right Witness, and the third and fourth Nieces form the Left Witness. From the Witnesses, using the same addition process, the iudex, or Judge, is formed. A sixteenth figure, the Reconciler or superiudex'', is also generated by adding the Judge and the First Mother, although this has become seen as extraneous and a "backup figure" in recent times.
Interpreting charts
The shield chart most likely provided an early visual guide to generating the figures, and the interpreted answer would center on the fifteenth and sixteenth figures, the Judge and Reconciler. Skilled geomancers observe the whole chart, interpreting (among other things) meanings of the figures based on where they place in the chart, the numerical significance of the total points, and the similarities produced by added figures. Generally, the Judge represents the answer to the question, the Right Witness describes the querent's side of the query, the Left Witness represents the quesited's side, and the Reconciler represents the effect of the outcome (or Judge) upon the querent. The skilled geomancer can deduce root causes to the situation, hidden influences, the outcome and its aftermath, and general trends and events in the querent's life through interpreting the chart.
Another method of evaluating a geomantic chart involves taking the total sum of all points from 16 figures within the shield chart. In order to evaluate how quickly the queried situation would resolve, Pietro d'Abano suggested that the total sum be compared to the sum of all points in the sixteen geomantic figures, which is 96. If the sum of the chart is 96, then the resolution of the query will be "swift, and neither slow nor doubtful;" in other words, that all things that could be acted upon in the situation described by the query would resolve without delay nor ahead of schedule. If the sum is less than 96, then it will resolve quickly, and in a degree proportional to the difference between 96 and the total. Conversely, if the sum is more than 96, then it will resolve slowly.
European geomancers provided an alternate method of interpreting the figures through the house chart, which feature the twelve astrological houses. Here, they assign the figures from the shield chart to the houses in the house chart; the order used differs between different circles of occultists. While European geomancers still used the shield chart to generate the figures and provide most answers, they augmented geomancy with astrological techniques in the house chart. Based upon the query, they could provide a deeper insight into the querent's life, factors shaping the query itself, and the extent of the situations involved. They took note when several houses shared the same figure; as this figure passes from one house to the next, it generally indicates that the same situation or event affects each of those houses.
Pietro d'Abano discusses the primary modes of perfection used in geomantic interpretations with significators in his geomancy essay. In astrological geomancy, the significators are chosen based upon the identity of the querent and the identity of the quesited. Generally, except when the querent asks about a situation about a subject with no immediate connection to themselves, the querent's significator is located in the first house (see Derivative house).
The quesited's significator is identified based upon the focus of the query: this is based upon the relation of the query to the astrological houses. Some questions require more than two significators, such as in a query involving several primary factors (e.g., two parties quarrelling over an estate). Queries that have a yes-or-no, or possible-impossible, answer can easily be answered with these modes of perfection. If the chart perfects, the answer is "yes". Otherwise, in the case of denial of perfection, "no".
The nature of the figures themselves should also be considered. If a chart perfects with negative figures, for instance, the matter will resolve but the querent may not like the result. On the other hand, if the chart does not perfect but the figures are good, then the matter will not resolve even though the querent can make do successfully without it.
In addition to modes of perfection, geomancers often took note of aspects between those figures that passed to other houses, and especially ones that made aspects to the significators. Often, when a chart denied perfection, geomancers would observe how the significators aspected each other; the aspects here retain similar meanings from astrology.
Christopher Cattan advocates using the strength of the astrological houses in determining the resolution. By observing the nature of the figures (good or ill, depending on the query) and what type of house they fall in (angular, succedent, or cadent), he judges the total effect of the figures on the query. The figures that fall in cadent houses have little to no effect, those that fall in succedent houses have a transient effect, and those that fall in angular houses have the strongest and most lasting effect upon the query.
Other examples of astrological technique used in geomancy include assigning zodiacal rulerships to the geomantic figures, linking geomantic figures to parts of the body based on zodiacal rulers, and assigning planetary spirits, intelligences, and genii to the figures based on their ruling planets.
Geomancy and mathematics
The four binary elements of each figure allow for 16 different combinations, each called a tableau. As each chart is generated from the four Mothers, there are a total number of 164, or 65,536, possible charts. Due to the mathematics of the chart, only figures that have an even number of points total can become Judges; each of the eight Judges then has 8,192 charts associated with it. Traditional practitioners of geomancy use this knowledge as a type of parity check on the chart to ensure that no mistakes have been made while computing the figures.
In each chart, if all sixteen figures are observed (the four Mothers, the four Daughters, the four Nieces, the Witnesses, Judge, and Reconciler), at least two of the figures must be the same. As the Reconciler is usually termed an optional figure, 16 combinations of Mother figures can yield a chart where the Mothers, Daughters, Nieces, Witnesses, and Judge are all unique.
Populus cannot appear in these charts, since mathematically it either requires two figures to be the same in order to be formed, or produces a duplicate figure when added to another figure. In such charts, the Judge will always be one of Conjunctio, Amissio, Carcer, or Acquisitio. The sixteen combinations of Mothers, in order from the First to the Fourth Mother, are
Puer, Caput Draconis, Tristitia, Albus
Conjunctio, Puella, Fortuna Major, Tristitia
Puella, Puer, Tristitia, Albus
Puella, Cauda Draconis, Tristitia, Albus
Rubeus, Laetitia, Puella, Puer
Rubeus, Laetitia, Cauda Draconis, Puella
Rubeus, Laetitia, Cauda Draconis, Caput Draconis
Rubeus, Laetitia, Caput Draconis, Puer
Acquisitio, Puella, Albus, Fortuna Major
Laetitia, Fortuna Minor, Puer, Conjunctio
Laetitia, Fortuna Minor, Acquisitio, Cauda Draconis
Cauda Draconis, Caput Draconis, Tristitia, Albus
Caput Draconis, Amissio, Fortuna Major, Tristitia
Caput Draconis, Carcer, Albus, Fortuna Major
Fortuna Minor, Rubeus, Puer, Amissio
Fortuna Minor, Rubeus, Carcer, Cauda Draconis
References
Divination
History of astrology | Arabic geomancy | [
"Astronomy"
] | 4,128 | [
"History of astrology",
"History of astronomy"
] |
72,215,815 | https://en.wikipedia.org/wiki/Hanseniaspora%20occidentalis | Hanseniaspora occidentalis is a species of yeast in the family Saccharomycetaceae. In its anamorph form, it was called Kloeckera javanica. It has been isolated in the wild from soil samples and vineyards. Samples of a variant have been isolated from orange juice and rotten oranges. It has demonstrated potential as an organism to reduce malic acid in wine production.
Taxonomy
The yeast was originally isolated by Albert Klöcker in the anamorphic form in 1912 and classified as Pseudosaccharomyces occidentalis. Because the Pseudosaccharomyces name had already been used since 1906 for an unrelated organism, Alexander Janke proposed an alternative name, Klöckeria, for the genus in 1923, which he corrected in 1928 to Kloeckera. Jacomina Lodder in 1934 found the yeast to be identical to another species, Kloeckera jensenii, also isolated by Klöcker in 1912, and reclassified it as a synonym of Kloeckera jensenii. A similar process occurred with yeasts identified by Klöcker as Pseudosaccharomyces indicus, Pseudosaccharomyces antillarum, and Pseudosaccharomyces willi, which Janke moved to Kloeckera indica, Kloeckera antillarum, and Kloeckera willi, and Lodder identified as three strains of the same species, consolidated into Kloeckera antillarum. Further study by Miller and Phaff in 1958 found that Kloeckera jensenii, Kloeckera javanica (originally Pseudosaccharomyces javanicus), Kloeckera lafarii, and Kloeckera antillarum were so similar to each other that they should be further combined into one species, Kloeckera javanica.
In 1974, yeast researcher Maudy Th. Smith observed a teleomorphic stage of the type strain of the original Kloeckera occidentalis yeast strain. As was custom at the time, teleomorphic forms of Kloeckera yeasts were identified as separate species in the Hanseniaspora genus, so it was designated as Hanseniaspora occidentalis. DNA Testing by S.A. Meyer in 1978 conclusively synonymized the anamorphic yeasts in the Kloeckera genus with their teleomorphic counterparts in the Hanseniaspora genus, and identified Kloeckera javanica as a synonym of Hanseniaspora occidentalis.
Description
Microscopic examination of the yeast cells in YM liquid medium after 48 hours at 25°C reveals cells that are 1.8 to 6.2 μm by 3 to 11 μm in size, apiculate, ovoid or sometimes spherical, appearing singly or in pairs. Reproduction is by budding, which occurs at both poles of the cell. In broth culture, sediment is present, and after one month a thin ring is formed.
Colonies that are grown on malt agar for one month at 25°C appear white to cream-colored, glossy, and smooth. Growth is flat on the edges and slightly raised at the center. The yeast generally does not form pseudohyphae on potato agar, but some strains have been observed to form either poorly-developed or well-developed pseudohyphae. The yeast has been observed to form one or two sherical and smooth ascospores with an equatorial ledge when grown for at least one week on 5% Difco malt extract agar.
The yeast can ferment glucose and sucrose, but not galactose, maltose, lactose, raffinose or trehalose. The yeast can assimilate glucose, sucrose, cellobiose, and salicin. Assimilation of glycerol is variable. It has a positive growth rate at 30°C, but no growth at 37°C. It can not grow on agar media containing 0.1% cycloheximide and can not utilize 2-keto-d-gluconate as a sole source of carbon.
Ecology
The type species of the original Pseudosaccharomyces occidentalis strain was isolated from a soil sample in Saint Croix, and other samples have been isolated from soil in Java and Saint Thomas. It has also been collected from Drosophila species in Brazil. Samples of a variant of the species, proposed as var. citrica, have been collected from orange juice in Italy and rotten oranges in Argentina. It is also commonly found in vineyards and the fruit flies that populate vineyards.
A 2022 study found that Muscaris wine must aerobically inoculated with Hanseniaspora occidentalis for three days followed by the addition of commercial wine yeast resulted in an almost complete elimination of malic acid in the wine, and produced a three-fold increase in ethyl acetate.
References
Saccharomycetes
Yeasts
Fungi described in 1974
Fungus species | Hanseniaspora occidentalis | [
"Biology"
] | 1,040 | [
"Yeasts",
"Fungi",
"Fungus species"
] |
72,215,965 | https://en.wikipedia.org/wiki/LogAbax | LogAbax was a French computer brand. Founded in 1942, the company was one of France's pioneers in computer manufacturing. The name is composed of two abbreviations: Log from logarithm and Abax from abacus.
History
The company was created in 1942 as “La Société Française des Brevets LogAbax”. In 1947 it employs twenty people and has a factory located at Malakoff. The company obtains a contract from CNRS for the construction of a "Couffignal machine", intended to be the fist French "electronic calculation machine". Between 1948 and 1950 LogAbax studies an electronic meter, related to the electronic calculator development.
In 1968 LogAbax and Bariquand et Marre merge, forming LogAbax SA.
The LX 500, a personal computer based on the Z80 microprocessor and running the CP/M operating system, is presented in 1978.
Due to poor results in the late 1970s, LogAbax files for bankruptcy in 1981, with Olivetti becoming the majority shareholder, creating a new entity named Société Nouvelle LogAbax.
The Persona 1600, a PC compatible machine with an Intel 8086 CPU (similar to Olivetti M24) is presented in 1985. Other rebranded Olivetti PCs follow (Persona 1800 and 1300).
In 1988 Olivetti France and Société Nouvelle LogAbax merge, becoming Olivetti-LogAbax.
Machines
LX 3200 - office computer, calculator, typewriter, printer, 1969
LX 2200, 2600 - office computer, calculator, typewriter, printer, 1974/75
LX 4200, 4300, 4400, 4500, 4600 - office computer, 1970s/75
LX 5000, 5076, 5200 - multi-user 16-bit computer, 64 Kb RAM, 1976/77
LX 2000, 2010, 2500 - 1976
LX 500, 518, 528 - Z80A, 128Kb RAM, CP/M, 1978
LX 3000, 3128, 3500 - multi-user office computer, 1980
Hyper 32 - fault tolerant redundant computer, 1983
Persona 800 - Z80 @ 4 MHz, 64KB RAM, CP/M, 1985
Persona 1600 (Olivetti M24) - Nanoréseau network machine, 8086 @ 8 MHz, 1985
Persona 1800 (Olivetti M28) - 80286 @ 8 MHz, 1986
Persona 1300 (Olivetti M19) - 8088 @ 4.77 MHz, 256KB RAM, 1986
3B modèle 400 (Olivetti CPS/32 Stratos) - 68030, VOS, 1986
See also
Computing for All, a French government plan to introduce computers to the country's pupils
References
Computer companies of France
History of computing in France
Defunct computer hardware companies
Defunct computer systems companies
Computer science education in France | LogAbax | [
"Technology"
] | 588 | [
"History of computing",
"History of computing in France"
] |
72,216,155 | https://en.wikipedia.org/wiki/Leo%20Rover | Leo Rover is a small-sized, four-wheeled, open-source robotic platform manufactured and developed in Wrocław, Poland, by fictionlab sp. z o.o.
Design and performance
The Leo Rover is a small, remotely controlled, four-wheeled rover, measuring 433 mm in length, 447 mm in width, and 249 mm in height. It weighs 6.5 kg and features in-hub DC motors with a 73.2:1 planetary gearbox and 12 CPR encoder to power each wheel. The wheels are made of rubber with foam inserts. The robot is equipped with a 5000 mAh Li-ion battery of 11.1 V DC. It can achieve a maximum linear speed of approximately 0.4 m/s and an angular speed of up to 60 deg/s. The front of the robot's body houses a 5 MPx camera with a 170-degree field of view. The rover's top surface features numerous mounting holes to attach additional hardware, and it has a nominal payload capacity of 5 kg.
The robot is equipped with a 2.4 GHz WiFi access point with an external antenna. The majority of the robot's structural components are 3D-printed, resulting in a watertight design rated at the IP64 level.
Software
The Leo Rover runs on Ubuntu Linux 20.04 with ROS Noetic Ninjammys, and a Raspberry Pi 4 as its main computer.
European Rover Challenge
From 2020 to 2022, the Leo Rover was the standard robot used in the remote formula of the European Rover Challenge.
Application area
Leo Rover serves as a development platform for implementing one’s own technological solutions by connecting external electronics, editing the open-source software, or modifying the robot’s design. Although the product is available to both individuals and companies, the majority of the consumers are universities and research facilities that use the robot for their projects and research.
References
Robotics
Mars rovers | Leo Rover | [
"Engineering"
] | 396 | [
"Robotics",
"Automation"
] |
72,218,761 | https://en.wikipedia.org/wiki/Software%20composition%20analysis | Software composition analysis (SCA) is a practice in the fields of Information technology and software engineering for analyzing custom-built software applications to detect embedded open-source software and detect if they are up-to-date, contain security flaws, or have licensing requirements.
Background
It is a common software engineering practice to develop software by using different components. Using software components segments the complexity of larger elements into smaller pieces of code and increases flexibility by enabling easier reuse of components to address new requirements. The practice has widely expanded since the late 1990s with the popularization of open-source software (OSS) to help speed up the software development process and reduce time to market.
However, using open-source software introduces many risks for the software applications being developed. These risks can be organized into 5 categories:
OSS Version Control: risks of changes introduced by new versions
Security: risks of vulnerabilities in components - Common Vulnerabilities & Exposures (or CVEs)
License: risks of Intellectual property (IP) legal requirements
Development: risks of compatibility between existing codebase and open-source software
Support: risk of poor documentation and Obsolete software components
Shortly after the foundation of the Open Source Initiative in February 1998, the risks associated with OSS were raised and organizations tried to manage this using spreadsheets and documents to track all the open source components used by their developers.
For organizations using open-source components extensively, there was a need to help automate the analysis and management of open source risk. This resulted in a new category of software products called Software Composition Analysis (SCA) which helps organizations manage open source risk.
SCA strives to detect all the 3rd party components in use within a software application to help reduce risks associated with security vulnerabilities, IP licensing requirements, and obsolescence of components being used.
Principle of operation
SCA products typically work as follows:
An engine scans the software source code, and the associated artifacts used to compile a software application.
The engine identifies the OSS components and their versions and usually stores this information in a database creating a catalog of OSS in use in the scanned application.
This catalog is then compared to databases referencing known security vulnerabilities for each component, the licensing requirements for using the component, and the historical versions of the component. For security vulnerability detection, this comparison is typically made against known security vulnerabilities (CVEs) that are tracked in the National Vulnerability Database (NVD). Some products use an additional proprietary database of vulnerabilities. For IP / Legal Compliance, SCA products will extract and evaluate the type of licensing used for the OSS component. Versions of components are extracted from popular open source repositories such as GitHub, Maven, PyPi, NuGet, and many others.
The results are then made available to end users using different digital formats. The content and format depend on the SCA product and may include guidance to evaluate and interpret the risk, and recommendations especially when it concerns the legal requirements of open source components such as strong or weak copyleft licensing. The output may also contain a Software Bill of Materials (SBOM) detailing all the open source components and associated attributes used in a software application
Usage
As SCA impacts different functions in organizations, different teams may use the data depending on the organization's corporation size and structure. The IT department will often use SCA for implementing and operationalizing the technology with common stakeholders including the chief information officer (CIO), the Chief Technology Officer (CTO), and the Chief Enterprise Architects (EA). Security and license data are often used by roles such as Chief Information Security Officers (CISO) for security risks, and Chief IP / Compliance officer for Intellectual Property risk management.
Depending on the SCA product capabilities, it can be implemented directly within a developer's Integrated Development Environment (IDE) who uses and integrates OSS components, or it can be implemented as a dedicated step in the software quality control process.
SCA products, and particularly their capacity to generate an SBOM is required in some countries such as the United States to enforce the security of software delivered to one of their agencies by a vendor.
Another common use case for SCA is for Technology Due diligence. Prior to a Merger & Acquisition (M&A) transaction, Advisory firms review the risks associated with the software of the target firm.
Strengths
The automatic nature of SCA products is their primary strength. Developers don't have to manually do an extra work when using and integrating OSS components. The automation also applies to indirect references to other OSS components within code and artifacts.
Weaknesses
Conversely, some key weaknesses of current SCA products may include:
Complex and labor-intensive deployment that can take months to get fully operational
Each product uses its own proprietary database of OSS components that can vary dramatically in terms of size and coverage
Limiting vulnerability data to reporting only on vulnerabilities officially reported in the NVD (which can be months after the vulnerability was originally discovered)
Lack of automated guidance on actions to take based on SCA reports and data
Lack of guidance on the legal requirements of OSS licenses that are detected
See also
Security testing
Open-source software
Common Vulnerabilities and Exposures
Open-source license
Software intelligence
References
Information technology
Computers | Software composition analysis | [
"Technology"
] | 1,078 | [
"Software engineering",
"Computer science",
"Software",
"nan"
] |
72,218,868 | https://en.wikipedia.org/wiki/Alkoxide | In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organyl substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as intermediates in various reactions, including the Williamson ether synthesis. Transition metal alkoxides are widely used for coatings and as catalysts.
Enolates are unsaturated alkoxides derived by deprotonation of a bond adjacent to a ketone or aldehyde. The nucleophilic center for simple alkoxides is located on the oxygen, whereas the nucleophilic site on enolates is delocalized onto both carbon and oxygen sites. Ynolates are also unsaturated alkoxides derived from acetylenic alcohols.
Phenoxides are close relatives of the alkoxides, in which the alkyl group is replaced by a phenyl group. Phenol is more acidic than a typical alcohol; thus, phenoxides are correspondingly less basic and less nucleophilic than alkoxides. They are, however, often easier to handle and yield derivatives that are more crystalline than those of the alkoxides.
Structure
Alkali metal alkoxides are often oligomeric or polymeric compounds, especially when the R group is small (Me, Et). The alkoxide anion is a good bridging ligand, thus many alkoxides feature or linkages. In solution, the alkali metal derivatives exhibit strong ion-pairing, as expected for the alkali metal derivative of a strongly basic anion.
Preparation
From reducing metals
Alkoxides can be produced by several routes starting from an alcohol. Highly reducing metals react directly with alcohols to give the corresponding metal alkoxide. The alcohol serves as an acid, and hydrogen is produced as a by-product. A classic case is sodium methoxide produced by the addition of sodium metal to methanol:
Other alkali metals can be used in place of sodium, and most alcohols can be used in place of methanol. Generally, the alcohol is used in excess and left to be used as a solvent in the reaction. Thus, an alcoholic solution of the alkali alkoxide is used. Another similar reaction occurs when an alcohol is reacted with a metal hydride such as NaH. The metal hydride removes the hydrogen atom from the hydroxyl group and forms a negatively charged alkoxide ion.
Properties
Reactions with alkyl halides
The alkoxide ion and its salts react with primary alkyl halides in an SN2 reaction to form an ether via the Williamson ether synthesis.
Hydrolysis and transesterification
Aliphatic metal alkoxides decompose in water as summarized in this idealized equation:
In the transesterification process, metal alkoxides react with esters to bring about an exchange of alkyl groups between metal alkoxide and ester. With the metal alkoxide complex in focus, the result is the same as for alcoholysis, namely the replacement of alkoxide ligands, but at the same time the alkyl groups of the ester are changed, which can also be the primary goal of the reaction. Sodium methoxide in solution, for example, is commonly used for this purpose, a reaction that is used in the production of biodiesel.
Formation of oxo-alkoxides
Many metal alkoxide compounds also feature oxo-ligands. Oxo-ligands typically arise via the hydrolysis, often accidentally, and via ether elimination:
Thermal stability
Many metal alkoxides thermally decompose in the range ≈100–300 °C. Depending on process conditions, this thermolysis can afford nanosized powders of oxide or metallic phases. This approach is a basis of processes of fabrication of functional materials intended for aircraft, space, electronic fields, and chemical industry: individual oxides, their solid solutions, complex oxides, powders of metals and alloys active towards sintering. Decomposition of mixtures of mono- and heterometallic alkoxide derivatives has also been examined. This method represents a prospective approach possessing an advantage of capability of obtaining functional materials with increased phase and chemical homogeneity and controllable grain size (including the preparation of nanosized materials) at relatively low temperature (less than 500–900 °C) as compared with the conventional techniques.
Illustrative alkoxides
Sodium methoxide
Sodium methoxide, also called sodium methylate and sodium methanolate, is a white powder when pure. It is used as an initiator of an anionic addition polymerization with ethylene oxide, forming a polyether with high molecular weight. Both sodium methoxide and its counterpart prepared with potassium are frequently used as catalysts for commercial-scale production of biodiesel. In this process, vegetable oils or animal fats, which chemically are fatty acid triglycerides, are transesterified with methanol to give fatty acid methyl esters (FAMEs).
Sodium methoxide is produced on an industrial scale and is available from a number of chemical companies.
Potassium methoxide
Potassium methoxide in alcoholic solution is commonly used as a catalyst for transesterification in the production of biodiesel.
References
Further reading
Functional groups
Coordination chemistry | Alkoxide | [
"Chemistry"
] | 1,170 | [
"Coordination chemistry",
"Alkoxides",
"Functional groups",
"Bases (chemistry)"
] |
72,219,089 | https://en.wikipedia.org/wiki/Hemangada%20Thakura | Hemangada Thakura was the King of Mithila between 1571 AD to 1590 AD. He was also an Indian Astronomer in 16th century. He was famous for his astronomical treatise Grahan Mala. The book told the dates of the eclipses for 1088 years from 1620 AD to 2708 AD. The dates of lunar and solar eclipse that Hemangad Thakur had fixed on the basis of his unique calculations are proving to be true till date.
Early life
Hemangada Thakura was born in a Maithil Brahmin family in Mithila region of present Bihar state in India. He born in 1530 AD. He was the grandson of Mahamahopadhyay Mahesha Thakura and the son of Gopal Thakur. Mahesh Thakur was also the King of Mithila in Khandwala Dynasty.
History
After the abdication of his father Gopal Thakur, he was handed over the throne of Mithila in 1571 AD. But he was not interested in governance. In 1572 AD, he was arrested and taken to Delhi and imprisoned for not paying taxes on time to the Mughal Empire. It is said that in prison he started writing mathematical calculations on the surface of the floor of the jail, then the jailer asked him about the mathematical figures drawn on the floor. Hemangada Thakura replied that he was trying to understand the motion of the Moon. Then the jailer spread the news that Hemangada Thakura had been mental mad. After hearing the news, the Mughal Emperor himself went to see Hemangada Thakura and asked about the mathematical calculations and figures drawn on the floor. Then Hemangada Thakura replied that he had calculated the dates of the eclipses for the next 500 years. After hearing the reply, the emperor immediately granted copperplate and pen to him for writing the calculations and told him that if his calculations became true, then he would be released from the prison. There in prison, he composed his famous book Grahan Mala which explained the eclipses for 1088 years. He predicated the date and time of the next lunar eclipse and informed the emperor. The prediction of the next lunar eclipse came to true on the same date and time as calculated by him. On composing this book, the Mughal emperor not only released him, but also returned the tax-free kingdom of Mithila.
Discovery in Astronomy
Hemangada Thakura calculated the dates of the eclipses for 1088 years from 1620 AD to 2708 AD on the basis of his unique calculations. The eclipses dates have been proved to be true till date. He composed an astronomical treatise book known as Grahan Mala which explains the dates of the eclipses. In making Panchang, scholars and Pandits take helps of this book. The manuscript of the book was preserved in Kameshwar Singh Darbhanga Sanskrit University, which has been stolen a few years back. By the way, in 1983 itself, the university had published this book, which is present in various libraries. Indian National Science Academy started a research project through national commission ( 2014 - 2022 ) by Vanaja V on the astronomical treatise Grahan Mala. The research project is known as “A Critical Study of Hemangada Thakkura’s Grahaṇamala” .
References
Astronomers
Mithila
Indian royalty
16th century in Asia
16th-century births | Hemangada Thakura | [
"Astronomy"
] | 684 | [
"People associated with astronomy",
"Astronomers"
] |
72,220,556 | https://en.wikipedia.org/wiki/Maia%20Vergniory | Maia Garcia Vergniory is a Spanish computational physicist who is a group leader at the Max Planck Institute for Chemical Physics of Solids. Her work in topological quantum chemistry investigates the phases of topological materials. She was elected Fellow of the American Physical Society in 2022.
Early life and education
Vergniory was born in Getxo. She was a doctoral researcher at the University of the Basque Country. Her research considered many-body effects on the interactions between excited electronic states and the mobile ions on surfaces. She started working on topological materials in 2012.
Research and career
Vergniory worked as a research fellow at the Ikerbasque and the Donostia International Physics Center. She studied novel materials and computational strategies to realise new condensed matter systems.
Verginory became interested in the design of new topological materials with optimised functional properties. Topological materials are insulators in the bulk but conductive on their surfaces. The conducting channels that facilitate current flow are robust and independent of size.
Vergniory studied the Inorganic Crystal Structure Database to identify topologically nontrivial materials. She designed a computational effort to simulate real materials and determine whether or not they showed topological properties. This included complex theoretical analysis that could classify topological phases, and information from materials scientists on whether materials were suitable or not. Vergniory uses her supercomputers to perform her calculations ab initio. In an interview with Physics World, Verginory said that she had been surprised by how many materials she identified with topological properties. As an output of this work, the high-order topological insulator Bi4Br4 was synthesised and studied experimentally. She showed that if it was possible to identify the symmetry of the crystalline symmetry of a material, she could easily anticipate the behaviour of the charge. She has since started investigating organic materials. She believes that topological crystals with a chiral structure will display several exotic physical phenomena.
Awards and honours
2017 L'Oréal-UNESCO For Women in Science Award
2022 Elected a Fellow of the American Physical Society
Selected publications
References
People from Getxo
Living people
University of the Basque Country alumni
Fellows of the American Physical Society
Spanish women chemists
Year of birth missing (living people)
Computational chemists
Materials scientists and engineers
Max Planck Institutes researchers
Condensed matter physicists
Basque people
21st-century chemists
21st-century Spanish physicists
Grenoble Alpes University alumni
Academic staff of the University of the Basque Country
21st-century Spanish women scientists | Maia Vergniory | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 502 | [
"Condensed matter physicists",
"Materials science",
"Computational chemists",
"Computational chemistry",
"Theoretical chemists",
"Condensed matter physics",
"Materials scientists and engineers"
] |
72,221,383 | https://en.wikipedia.org/wiki/Lead%28II%29%20perchlorate | Lead(II) perchlorate is a chemical compound with the formula Pb(ClO4)2·xH2O, where is x is 0,1, or 3. It is an extremely hygroscopic white solid that is very soluble in water.
Preparation
Lead perchlorate trihydrate is produced by the reaction of lead(II) oxide, lead carbonate, or lead nitrate by perchloric acid:
Pb(NO3)2 + HClO4 → Pb(ClO4)2 + HNO3
The excess perchloric acid was removed by first heating the solution to 125 °C, then heating it under moist air at 160 °C to remove the perchloric acid by converting the acid to the dihydrate. The anhydrous salt, Pb(ClO4)2, is produced by heating the trihydrate to 120 °C under water-free conditions over phosphorus pentoxide. The trihydrate melts at 83 °C. The anhydrous salt decomposes into lead(II) chloride and a mixture of lead oxides at 250 °C. The monohydrate is produced by only partially dehydrating the trihydrate, and this salt undergoes hydrolysis at 103 °C.
The solution of anhydrous lead(II) perchlorate in methanol is explosive.
Applications
Lead perchlorate has a high nucleon density, making it a viable detector for hypothetical proton decay.
References
Lead(II) compounds
Perchlorates | Lead(II) perchlorate | [
"Chemistry"
] | 319 | [
"Perchlorates",
"Salts"
] |
72,221,650 | https://en.wikipedia.org/wiki/Hantao%20Ji | Hantao Ji is a professor of astrophysical sciences at Princeton University. He received the John Dawson Award in 2002 for his work on magnetic reconnection. He is also a fellow of the American Physical Society.
References
Plasma physicists
Year of birth missing (living people)
Living people | Hantao Ji | [
"Physics"
] | 58 | [
"Plasma physicists",
"Plasma physics"
] |
72,223,183 | https://en.wikipedia.org/wiki/Rockingham%20Kiln | The Rockingham, or Waterloo, Kiln in Swinton, South Yorkshire, England, is a pottery kiln dating from 1815. It formed part of the production centre for the Rockingham Pottery which, in the early 19th century, produced highly-decorative Rococo porcelain. The pottery failed in the mid-19th century, and the kiln is one of the few remaining elements of the Rockingham manufactory. It is a Grade II* listed building and forms part of the Rockingham Works Scheduled monument. The kiln is currently on the Historic England Heritage at Risk Register.
History
The original factory on the Swinton site produced simple earthenware pottery. The first recorded operator was a Joseph Flint, who in the 1740s was renting the site from the Marquess of Rockingham. A partnership with the Leeds Pottery failed and was dissolved by 1806. The subsequent owners, the Brameld family, built the Rockingham Kiln, and other structures on the site, in 1815. The date, the year of the Battle of Waterloo, led to the kiln's alternative name, the Waterloo Kiln. Despite the Brameld's investigations into the production of high-quality porcelain, the venture continued to be unsuccessful and the firm was extricated from a further bankruptcy in 1826 only by the intervention of William Fitzwilliam, 4th Earl Fitzwilliam, who had inherited the Wentworth Woodhouse estate from his uncle, the second Marquess of Rockingham.
The Earl's patronage, permitting the use of the Rockingham name and family crest, together with providing direct financial support, saw the Rockingham Pottery develop into a major producer of elaborate rococo-style porcelain, which enjoyed royal endorsement at home and considerable sales abroad. The factory produced major pieces including a full desert service for William IV which took eight years to complete. Ruth Harman, in her 2017 revised volume, Yorkshire West Riding: Sheffield and the South, of the Pevsner Buildings of England series, notes that "perfection was their undoing" and by 1842 the Rockingham firm was again bankrupt and the site was closed.
The Pottery Ponds site is administered by Rotherham Museums. As at November 2022, the kiln is on Historic England's Heritage at Risk Register. Recent interest in the Rockingham Works has seen the erection of a commemorative sculpture in Swinton in 2003, and a community heritage project at the site in 2021, directed by the artist Carlos Cortes.
Architecture and description
The Rockingham Kiln is believed to be the only surviving such pottery kiln in Yorkshire, and one of the few remaining in England. The high kiln is bottle-shaped and is constructed in English Bond red brick. Harman records that the structure is more accurately described as a "bottle-shaped brick oven [containing] a kiln". The kiln is a Grade II* listed building and forms part of the Rockingham Works Scheduled monument.
Notes
References
Sources
Grade II* listed buildings in South Yorkshire
Swinton, South Yorkshire
Buildings and structures in the Metropolitan Borough of Rotherham
British porcelain
English pottery
Ceramics manufacturers of England
Structures on the Heritage at Risk register
Kilns | Rockingham Kiln | [
"Chemistry",
"Engineering"
] | 634 | [
"Chemical equipment",
"Kilns"
] |
72,225,585 | https://en.wikipedia.org/wiki/HD%2044506 | HD 44506 is a solitary, blue hued star located in the southern constellation Columba. The object is also called HR 2288, which is its Bright Star Catalog designation. It has an average apparent magnitude of 5.52, making it faintly visible to the naked eye under ideal conditions. HD 44506 is located relatively far at a distance of 1,800 light years based on Gaia DR3 parallax measurements but is receding with a heliocentric radial velocity of .
Emission lines were first noticed in HD 44506's spectrum in 1964. They were again observed by Karl G. Heinze. It has been suspected to be variable since 1963, but a 1977 search for β Cepheids found inconclusive results; the star is variable in the visual passband but not the ultraviolet passband. As of 2017, the GCVS lists HD 44506 as a suspected variable. In 1982, HD 44506 was officially catalogued as a Be star by Mecerdes Jaschek and Daniel Egret.
This is a hot B-type main-sequence star with a stellar classification of B3 V. It has 12.2 times the mass of the Sun and is estimated to be 13 million years old. HD 44506 has a radius of and an effective temperature of . This yields a bolometric luminosity 18,951 times that of the Sun from its photosphere. Like many hot stars it spins rapidly, having a projected rotational velocity of .
References
Further reading
B-type main-sequence stars
Be stars
Suspected variables
Columba (constellation)
Columbae, 90
2288
CD-34 02806
044506
030143 | HD 44506 | [
"Astronomy"
] | 353 | [
"Columba (constellation)",
"Constellations"
] |
72,226,693 | https://en.wikipedia.org/wiki/Future-oriented%20technology%20analysis | Future-oriented technology analysis (FTA) is a collective term from futures studies for analyzing future technology and its consequences. It includes technology intelligence, technology forecasting, technology roadmapping, technology assessment, and technology foresight. Technology Futures Analysis or Technology Future Analysis (TFA) is a synonym.
Future-oriented technology analysis shares common methods with horizon scanning.
Definitions
Methods
References
Technology assessment
Technology forecasting | Future-oriented technology analysis | [
"Technology"
] | 83 | [
"Science and technology studies",
"nan",
"Technology assessment"
] |
72,226,721 | https://en.wikipedia.org/wiki/UX%20Orionis | UX Orionis is a variable star in the constellation of Orion. It is a Herbig Ae star, located about 1000 light years from the Earth. At its brightest it is a magnitude 9.5 object, so it is too faint to be seen with the naked eye. UX Orionis is the prototype of the UX Orionis class of variable stars (often called "UXors"), which are young stellar objects that exhibit large (greater than 2.8 magnitude), irregular changes in visual band brightness. UX Orionis was discovered by Henrietta Swan Leavitt.
UX Orionis is surrounded by a circumstellar disk, and the star's photometric variability appears to be caused by episodes during which the star is obscured by dusty material within the circumstellar disk.
References
Orion (constellation)
Herbig Ae/Be stars
293782
23602
J05042998-0347142
Orionis, UX | UX Orionis | [
"Astronomy"
] | 203 | [
"Constellations",
"Orion (constellation)"
] |
72,226,892 | https://en.wikipedia.org/wiki/Gabe%20Okoye | Gabe Okoye is Nigerian–American civil engineer, former chair, and a current commissioner of planning in Gwinnett County. On November 8, 2022, he became a legislator elect at the 2022 US midterm elections representing Georgia State and he took office on January 9, 2023.
Biography
Okoye is a native of Enugwu-Agidi. He relocated to United States in 1981. He began working as a security guard. He later enrolled in college where he became a civil engineer and eventually founded a company called Essex Geoscientist. Okoye is married with four children and has been living in Atlanta since 1992
Political career
Okoye is a Democrat and he became the Gwinnett party chairman in 2016. In 2018, he recorded massive wins that captured 13 seats out of the 25 seats available in the county. This historic wins made the Georgia House of Representatives with Resolution 313 of 2019 declared November 6 of 2019 as Gabe Okoye Leadership Day.
References
African-American people in Georgia (U.S. state) politics
Living people
Georgia (U.S. state) Democrats
Civil engineers
Candidates in the 2022 United States House of Representatives elections
Year of birth missing (living people)
Nigerian emigrants to the United States
American politicians of Nigerian descent
21st-century African-American politicians
African-American state legislators in Georgia (U.S. state)
Democratic Party members of the Georgia House of Representatives
21st-century members of the Georgia General Assembly | Gabe Okoye | [
"Engineering"
] | 299 | [
"Civil engineering",
"Civil engineers"
] |
72,227,730 | https://en.wikipedia.org/wiki/Vertebrate%20visual%20opsin | Vertebrate visual opsins are a subclass of ciliary opsins and mediate vision in vertebrates. They include the opsins in human rod and cone cells. They are often abbreviated to opsin, as they were the first opsins discovered and are still the most widely studied opsins.
Opsins
Opsin refers strictly to the apoprotein (without bound retinal). When an opsin binds retinal to form a holoprotein, it is referred to as Retinylidene protein. However, the distinction is often ignored, and opsin may refer loosely to both (regardless of whether retinal is bound).
Opsins are G-protein-coupled receptors (GPCRs) and must bind retinal — typically 11-cis-retinal — in order to be photosensitive, since the retinal acts as the chromophore. When the Retinylidene protein absorbs a photon, the retinal isomerizes and is released by the opsin. The process that follows the isomerization and renewal of retinal is known as the visual cycle. Free 11-cis-retinal is photosensitive and carries its own spectral sensitivity of 380nm. However, to trigger the phototransduction cascade, the process that underlies the visual signal, the retinal must be bound to an opsin when it is isomerized. The retinylidene protein has a spectral sensitivity that differs from that of free retinal and depends on the opsin sequence.
While opsins can only bind retinal, there are two forms of retinal that can act as the chromophore for vertebrate visual opsins:
Retinal 1 (11-cis-Retinal) - the common form present in most opsins
Retinal 2 (11-cis-3,4-Dehydroretinal) - a rarer form that is relatively red-shifted compared to retinal 1.
Animals living on land and marine fish form their visual pigments exclusively with retinal 1. However, many freshwater fish and amphibians can also form visual pigments with retinal 2, depending on the activation of the enzyme retinal-3,4-desaturase (GO:0061899). Many of these species can switch between these chromophores during their life cycle, to adapt to a changing habitat.
Function
Isomerization of 11-cis-retinal into all-trans-retinal by light induces a conformational change in the protein that activates the phototransduction pathway.
Subclasses
There are two classes of vertebrate visual opsin, differentiated by whether they are expressed in rod or cone photoreceptors.
Cone opsins
Opsins expressed in cone cells are called cone opsins. The cone opsins are called photopsins when unbound to retinal and iodopsins when bound to retinal. Cone opsins mediate photopic vision (daylight). Cone opsins are further subdivided according to the spectral sensitivity of their iodopsin, namely the wavelength at which the highest light absorption is observed (λmax).
Rod opsins
Opsins expressed in rod cells are called rod opsins. The rod opsins are called scotopsins when unbound to retinal and rhodopsins or porphyropsins when bound to retinal (1 and 2, respectively). Rod opsins mediate scotopic vision (dim light). Compared to cone opsins, the spectral sensitivity of rhodopsin is quite stable, not deviating far from 500 nm in any vertebrate.
Evolution
Extant vertebrates typically have four cone opsin classes (LWS, SWS1, SWS2, and Rh2) as well as one rod opsin class (rhodopsin, Rh1), all of which were inherited from early vertebrate ancestors. These five classes of vertebrate visual opsins emerged through a series of gene duplications beginning with LWS and ending with Rh1, according to the cladogram to the right; this serves as an example of neofunctionalization. Each class has since evolved into numerous variants. Evolutionary relationships, deduced using the amino acid sequence of the opsins, are frequently used to categorize cone opsins into their respective class. Mammals lost Rh2 and SWS2 classes during the nocturnal bottleneck. Primate ancestors later developed two LWS opsins (LWS and MWS), leaving humans with 4 visual opsins in 3 classes.
History
George Wald received the 1967 Nobel Prize in Physiology or Medicine for his experiments in the 1950s that showed the difference in absorbance by these photopsins (see image).
See also
Color blindness
Melanopsin
Retinylidene protein
Rhodopsin
Visual cycle
Visual phototransduction
References
G protein-coupled receptors
Vision | Vertebrate visual opsin | [
"Chemistry"
] | 1,048 | [
"G protein-coupled receptors",
"Signal transduction"
] |
72,230,055 | https://en.wikipedia.org/wiki/Neoproterozoic%20oxygenation%20event | The Neoproterozoic Oxygenation Event (NOE), also called the Second Great Oxidation Event, was a geologic time interval between around 850 and 540 million years ago during the Neoproterozoic era, which saw a very significant increase in oxygen levels in Earth's atmosphere and oceans. Taking place after the end to the Boring Billion, an euxinic period of extremely low atmospheric oxygen spanning from the Statherian period of the Paleoproterozoic era to the Tonian period of the Neoproterozoic era, the NOE was the second major increase in atmospheric and oceanic oxygen concentration on Earth, though it was not as prominent as the Great Oxidation Event (GOE) of the Neoarchean-Paleoproterozoic boundary. Unlike the GOE, it is unclear whether the NOE was a synchronous, global event or a series of asynchronous, regional oxygenation intervals with unrelated causes.
Evidence for oxygenation
Carbon isotopes
Beginning around 850 Mya to around 720 Mya, a time interval roughly corresponding to the Late Tonian, between the end of the Boring Billion and the onset of the Cryogenian “Snowball Earth”, marine deposits record a very significant positive carbon isotope excursion. These elevated δ13C values are believed to be linked to an evolutionary radiation of eukaryotic plankton and enhanced organic burial, which in turn indicate a spike in oxygen production during this interval. Further positive carbon isotope excursions occurred during the Cryogenian. Although several negative carbon isotope excursions, associated with warming events, are known from the Late Tonian all the way up to the Proterozoic-Phanerozoic boundary, the carbon isotope record nonetheless maintains a noticeable positive trend throughout the Neoproterozoic.
Nitrogen isotopes
δ15N data from 750 to 580 million year-old marine sediments hailing from four different Neoproterozoic basins show similar nitrogen isotope ratios to modern oceans, with a mode of +4% and a range from -4% to +11%. No significant change is observed across the Cryogenian-Ediacaran boundary, implying that oxygen was already ubiquitous in the global ocean as early as 750 Mya, during the Tonian period.
Sulfur isotopes
Seawater sulfate δ34S values, which saw a gradual increase over most of the Neoproterozoic punctuated by major drops during glaciations, show a significant positive excursion during the Ediacaran, with a corresponding decrease in pyritic δ34S. High fractionation rates between sulfte and sulfide indicate an increase in the availability of sulfate in the water column, which in turn is indicative of increased reaction of pyrite with oxygen. In addition, genetic evidence points to the occurrence of a radiation of non-photosynthetic sulfide-reducing bacteria during the Neoproterozoic. Through bacterial sulfur disproportionation, such bacteria further deplete marine sulfide of heavier sulfur isotopes. Because such bacteria require significant amounts of oxygen to survive, an oxygenation event during the Neoproterozoic raising oxygen concentrations to over 5-18% of modern levels is believed to have been a necessary prerequisite for the diversification of these microorganisms.
Strontium isotopes
δ13C can reliably indicate changes in net primary productivity and oxygenation if the rates of weathering into the oceans and carbon dioxide outgassing remain constant or increase, since a decrease in either of these could cause a positive δ13C excursion through continued preferential biological consumption of carbon-12 by existing communities while the supply of available carbon decreased, without indicating an increase in primary productivity and oxygen production. The ratio of strontium-87 to strontium-86 is used as a determinant of the relative contribution of continental weathering to the ocean's nutrient supply; an increase in this ratio, as observed throughout the Neoproterozoic and into the Cambrian until reaching a peak at the end of the Cambrian, suggests a rise in continental weathering and bolsters evidence from carbon isotope ratios for high oxygenation in this interval of time.
Chromium isotopes
Surface oxidation of Cr(III) to Cr(VI) causes isotopic fractionation of chromium; Cr(VI), typically present in the environment as either chromate or dichromate, has elevated values of δ53Cr, or the ratio of chromium-53 to chromium-52, whereas bacterial reduction of Cr(VI) to Cr(III) is associated with negative chromium isotope excursions. Following the riverine transport of oxidised chromium into the ocean, the reaction reducing Cr(VI) back into Cr(III) and subsequently oxidising ferrous iron into ferric iron is highly efficient at sequestering Cr(VI), as is the precipitation of Cr(III) with ferric oxyhydroxide, meaning that chemically precipitated chromium isotope ratios in sediments abundant in ferric iron accurately reflect seawater chromium isotope ratios at the time of deposition. Because efficient oxidation of Cr(III) to Cr(VI) is only possible in the presence of the catalyst manganese dioxide, which is only stable and abundant at high oxygen fugacities, a positive excursion of δ53Cr indicates an increase in atmospheric oxygen concentrations. Banded iron formations (BIFs) deposited during the Neoproterozoic consistently display highly positive δ53Cr values, from 0.9% to 4.9%, demonstrating the era's oxygenation of the atmosphere. Oxidative chromium cycling began approximately 0.8 Ga, indicating that oxygen level rise began well before the Cryogenian glaciations. Chromium isotopes also show that during the Cryogenian interglacial interval, between the Sturtian and Marinoan glaciations, oxygenation of the ocean and atmosphere was slow and subdued; this interval marked a lull in the NOE.
Molybdenum isotopes
δ98Mo values were slightly higher during the Late Ediacaran than in the Cryogenian or the Early and Middle Ediacaran. This isotopic proxy indicates the level of oxygenation of the Late Ediacaran ocean was comparable to that of Mesozoic oceanic anoxic events.
Uranium isotopes
The very low values of δ238U, commonly used as an isotopic measurement of changes in seawater oxygenation, during much of the Neoproterozoic have been interpreted to reflect progressive oxygenation punctuated by temporary, transient expansions of anoxic and euxinic waters. During the Early Ediacaran, the shift in uranium isotopes occurred in tandem with enrichment in light carbon isotopes.
Causes
Increase in nitrogen fixation
During the Boring Billion, open ocean productivity was very low compared to the Neoproterozoic and Phanerozoic as a result of the absence of planktonic nitrogen-fixing bacteria. The evolution and radiation of nitrogen-fixing bacteria and non-nitrogen-fixing picocyanobacteria capable of occupying marine planktonic niches and consequent changes to the nitrogen cycle during the Cryogenian are believed to be a culprit behind the rapid oxygenation of and removal of carbon dioxide from the atmosphere, which also helps explain the development of extremely severe glaciations that characterised this period of the Neoproterozoic.
Increase in day length
The slowdown of the Earth's rotation and corresponding increase in day length has been suggested as a possible cause of the NOE on the basis of experimental findings that cyanobacterial productivity is higher during longer periods of uninterrupted daylight compared to shorter periods more frequently interrupted by darkness.
Organic carbon burial
The Neoproterozoic saw organic carbon burial occur in large lakes with anoxic bottom waters on a massive scale. As carbon was locked away in sedimentary rock, it was unable to be oxidised, permitting a buildup of atmospheric oxygen.
Phosphorus removal
The increasing diversity of eukaryotes has been proposed as a cause of increased deep ocean oxygenation by means of phosphorus removal from the deep ocean. The evolution of large multicellular organisms led to increased amounts of organic matters sinking to the seafloor (marine snow). This, combined with the evolution of benthic filter feeders (e.g. choanoflagellates and primitive poriferans such as Otavia), is believed to have shifted oxygen demand further down in the water column, which would result in a positive feedback loop wherein phosphorus was removed from the ocean, which reduced productivity and decreased oxygen demand, which in turn led to increasing oxygenation of deep ocean water. Increasingly well oxygenated oceans enabled further eukaryotic dispersal, which likely acted as a positive feedback loop that accelerated oxygenation.
Consequences
Glaciation
The rapid increase in organic carbon sequestration as a result of the increased rates of global photosynthesis by both cyanobacteria and eukaryotic photoautotrophs (green and red algae), occurring in conjunction with an increase in silicate weathering of continental flood basalts resulting from the breakup of the supercontinent Rodinia, is believed to have been a trigger of the Sturtian and Marinoan glaciations during the Cryogenian, the middle period of the Neoproterozoic.
Biological diversity
During the Tonian, very early multicellular organisms may have evolved and diversified in oxygen "oases" in the deep oceans, which acted as cradles in these early stages of eukaryote evolution. However, the persistence of anoxia and euxinia over the late Tonian despite some increases in oxygen content meant eukaryotic diversity overall remained low. Over the course of the Ediacaran period, the oceans gradually became better oxygenated, with the time interval immediately after the Gaskiers Glaciation displaying evidence of significantly increasing marine oxygen content. The rapid diversification of multicellular life during this geologic period has been attributed by some authors to an increase in oxygen content, enabling the iconic oxygen-consuming multicellular eukaryotes of the Ediacaran biota to become ubiquitous and widespread. Initially restricted to deeper, colder waters that possessed the most dissolved oxygen, metazoan life gradually expanded into warmer zones of the ocean as global oxygen levels rose.
See also
Great Oxidation Event
Avalon explosion
Cambrian explosion
Silurian-Devonian Terrestrial Revolution
References
Neoproterozoic events
Origin of life
Oxygen
Events in the geological history of Earth
Evolution of the biosphere
Meteorological hypotheses | Neoproterozoic oxygenation event | [
"Biology"
] | 2,189 | [
"Biological hypotheses",
"Evolution of the biosphere",
"Origin of life"
] |
72,230,901 | https://en.wikipedia.org/wiki/Miyake%20event | A Miyake event is an observed sharp enhancement of the production of cosmogenic isotopes by cosmic rays. It can be marked by a spike in the concentration of radioactive carbon isotope in tree rings, as well as and in ice cores, which are all independently dated. At present, five significant events are known (7176 BCE, 5259 BCE, 664-663 BCE (historically referred to as 660 BCE), 774 CE, 993 CE) for which the spike in is quite remarkable, i.e. above 1% rise over a period of two years, and four more events (12,350BCE, 5410 BCE, 1052 CE, 1279 CE) need independent confirmation. It is not known how often Miyake events occur, but from the available data it is estimated to be every 400 to 2,400 years.
There is strong evidence that Miyake events are caused by extreme solar particle events and they are likely related to super-flares discovered on solar-like stars. Although Miyake events are based on extreme year-to-year rises of concentration, the duration of the periods over which the levels increase or stay at high levels is longer than one year. However, a universal cause and origin of all the events is not yet established in science, and some of the events may be caused by other phenomena coming from outer space (such as a gamma-ray burst).
A recently reported sharp spike in that occurred between 12,350 and 12,349BCE may represent the largest known Miyake event. This event was identified during a study conducted by an international team of researchers who measured radiocarbon levels in ancient trees recovered from the eroded banks of the Drouzet River, near Gap, France, in the Southern French Alps. According to the initial study the new event is roughly twice the size of the Δ increase for more recent 774CE and 993CE events, but the strength of the corresponding solar storm is not yet assessed. However, the newly discovered 12,350 BCE event has not yet been independently confirmed in wood from other regions, nor it is reliably supported by a clear corresponding spike in other isotopes (such as beryllium-10) that are usually used in combination for absolute radiometric dating.
A Miyake event occurring in modern conditions might have significant impacts on global technological infrastructure such as satellites, telecommunications, and power grids.
Discovery
The events are named after the Japanese physicist Fusa Miyake who, as a doctoral student, was the first one to identify these radiocarbon spikes and published the results with co-authors in 2012 in the journal Nature. The investigation at that time found a strong increase in the annual rings of Japanese cedars for the years 774/775. The event of 775 was independently discovered, using the low-resolution IntCal data.
In 2013, Miyake and co-authors published the discovery of another similar radiocarbon spike in the years 993/994. In December 2013, Miyake received her Doctor of Science degree from Nagoya University.
Time benchmark
After a Miyake event is well-studied and confirmed, it can serve as a reference time benchmark, a "year-stamp", enabling more precise dating of historical buildings, objects, and events. Six diverse historical occurrences, from archaeological sites to natural disasters, have thus been dated to a specific year, using Miyake events as benchmarks and counting tree rings. For example, wooden construction elements from the Viking archaeological site at L'Anse aux Meadows in Newfoundland were dated by identifying the spike of 993 CE in a sequence of tree-rings, which showed that the wood is from a tree felled in 1021 CE, thus definitely confirming Viking presence in the Americas at least before 1021 CE. Another study performed on the tree-rings of wooden building remains from the
Neolithic waterlogged site of Dispilio in north-western Greece, identified the Miyake event of 5259 BC, thus for a first time absolutely dating a Neolithic site in Europe from the 6th millennium BC to a single calendar year.
See also
Carrington Event
Coronal mass ejection
Dendrochronology
Geomagnetic storm
Solar storm
References
External links
Researchers succeed for first time in accurately dating a 7,000-year-old prehistoric settlement using cosmic rays – May 21, 2024 – University of Bern
Geomagnetic storms
Astrophysics
Geophysics
Stratigraphy
Dating methods | Miyake event | [
"Physics",
"Astronomy"
] | 917 | [
"Astronomical sub-disciplines",
"Applied and interdisciplinary physics",
"Astrophysics",
"Geophysics"
] |
72,231,560 | https://en.wikipedia.org/wiki/ETransportation | eTransportation is a peer-reviewed open-access scientific journal covering all modes of transportation by using electricity (vehicles, ships and airplanes). The journal was established in 2019 and is published by Elsevier. The editor-in-chief is Minggao Ouyang (Tsinghua University). It is emphasized that efforts to advocate UN's goals of sustainable development are welcomed, specifically "Affordable and clean energy".
Abstracting and indexing
The journal is abstracted and indexed in Ei Compendex, Scopus, and the Science Citation Index Expanded. According to the Journal Citation Reports, the journal has a 2021 impact factor of 1.65.
References
External links
Electrical and electronic engineering journals
Academic journals established in 2019
English-language journals
Elsevier academic journals
Creative Commons Attribution-licensed journals
Continuous journals
Transportation journals | ETransportation | [
"Engineering"
] | 171 | [
"Electrical engineering",
"Electronic engineering",
"Electrical and electronic engineering journals"
] |
72,231,814 | https://en.wikipedia.org/wiki/International%20Journal%20of%20Plasticity | The International Journal of Plasticity is a monthly peer-reviewed scientific journal that covers research that relates to micro and macro plastic deformation and fracture for isotropic and anisotropic materials.The journal is published by Elsevier and the editors-in-chief is Akhtar S. Khan (University of Maryland, Baltimore County).
Abstracting and indexing
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2022 impact factor of 9.8.
See also
Fracture mechanics
Solid mechanics
References
External links
Materials science journals
Elsevier academic journals
Monthly journals
English-language journals
Academic journals established in 1985 | International Journal of Plasticity | [
"Materials_science",
"Engineering"
] | 131 | [
"Materials science journals",
"Materials science"
] |
67,823,404 | https://en.wikipedia.org/wiki/Lombardo%20methylenation | In organic chemistry, the Lombardo methylenation is a name reaction that allows for the methylenation of carbonyl compounds with the use of Lombardo's reagent, which is a mix of zinc, dibromomethane, and titanium tetrachloride.
Applications
The Lombardo methylenation has been used in the total synthesis of tetrodotoxin and hirustene.
References
Name reactions | Lombardo methylenation | [
"Chemistry"
] | 89 | [
"Name reactions",
"Chemical reaction stubs",
"Organic redox reactions",
"Organic reactions"
] |
67,828,645 | https://en.wikipedia.org/wiki/Project%20Schoolflight | Project Schoolflight was a youth outreach program of the Experimental Aircraft Association (EAA) which was jointly co-founded in 1955 by EAA founder Paul Poberezny and Robert D. Blacker, the director of the Aviation Industrial Arts program at St. Rita of Cascia High School in Chicago, Illinois and President of EAA Chapter 15.
Poberezny had written series of three articles entitled "Build this plane (Baby Ace) for $800, Including Engine" which ran in consecutive 1955 monthly issues of Mechanix Illustrated magazines and Blacker decided to use the plans for the first Schoolflight homebuilt aircraft project. Blacker contacted Poberezny and he supplied a copy of the Baby Ace plans for the program at no charge. Poberezny thought that Blacker's program could provide him with a start to fulfilling one of his lifetime dreams - to have an "airplane building factory" for homebuilt aircraft. It was from these discussions that both men agreed to co-found Project Schoolflight together.
The Project Schoolflight program was initially overseen by both men but it grew so quickly that it became administered by the EAA's Air Museum Foundation instead. The project dissolved around 1978, and would eventually help inspire the founding of the very successful EAA Young Eagles program, established in 1992.
History
In 1952, prior to founding the EAA, Paul Poberezny purchased all of the inventory and the legal rights of the then defunct Ace Aircraft Manufacturing Company, including all rights and plans to the Baby Ace sport aircraft, all of which had been left abandoned in an airport hangar in Madison, Wisconsin.
Early in 1955, Poberezny built a Baby Ace on which he painted to advertise Mechanix Illustrated, which had agreed to publish his project story, to include blueprints, of his Baby Ace build over three consecutive monthly issues. Robert D. Blacker, the aeronautical instructor for St. Rita of Cascia High School and EAA Chapter 15 President, read Poberenzy's story in MI and thought that building a Baby Ace would be an ideal class project. Blacker contacted Poberenzy, who provided Baby Ace plans at no cost and together they founded Project Schoolflight.
In September of that year, Blacker and his students began building their first Baby Ace for Project Schoolflight, which would be named the Spirit of Cascia, after Cascia, St. Rita's hometown.
Participating in the project inspired the students to form Chapter #39, the first Junior EAA Chapter, including electing student officers. Chapter 39 students also volunteered at the EAA Fly-Ins from 1957 until 1960 where they helped run the competitive flying events.
In 1957, the Spirit of Cascia was completed. The second airplane was an EAA Biplane, completed in 1960, five years after the start of the program.
At the 1957 EAA Fly-in in Milwaukee, Wisconsin, the "Spirit of Cascia" won an EAA award for "Outstanding Achievement" which was presented by Ray Stits. At the 1958 Fly-in, Blacker was awarded the Mechanix Illustrated Trophy for "Outstanding Achievements in Home-Built Aircraft" for his work in starting Project Schoolflight. In 1961, the Spirit of Cascia was sold to an airplane enthusiast from Pine Bluff, Arkansas. As of 2018 it resides in storage at the Greater Saint Louis Air & Space Museum.
The EAA Biplane completed made its first flight at the 1961 EAA Fly-in in Rockford, Illinois and was put on permanent display in the EAA Aviation Museum, then located in Franklin, Wisconsin.
In 1957, Blacker made available his high school shop for Chicago EAA Chapter #15 to hold their monthly
meetings there to help expand awareness of the project and gain wider involvement. Blacker soon became President of EAA Chapter 15 while continuing to serve as the adult sponsor and advisor to Junior Chapter #39.
In 1959, Blacker and Poberezny both appeared on a local TV show on WMVS-TV in Milwaukee. Blacker explained how Project Schoolflight worked, while Poberezny explained EAA activities.
Project Schoolflight quickly spread across the US, with thousands of students involved. By 1961 almost 400 airplanes were being built at more than 300 schools. In addition ten American prisons used Project Schoolflight as an inmate rehabilitation program.
In 1962, due to the project's success, the EAA formalized the establishment of junior EAA chapters, with members to be under 19 years of age, with an adult advisor and sponsored by a regular EAA Chapter.
In 1974, EAA member Sam Burgess flew a four month tour covering 48 states. This outreach program, flown in an Acro Sport I biplane, was intended to encourage schools to either continue in the program or to create their own Project Schoolflight programs by building an Acro Sport, a direct descendant design of the EAA Biplane. Burgess timed his tour so that his final stop would be Oshkosh, Wisconsin, to coincide with the start of the 1974 fly-in there.
One of the EAA Museum's centerpiece attractions is the 1903 Wright Flyer replica built by EAA and the Project Schoolflight students at Blackhawk Technical Institute in Janesville, Wisconsin, in 1978.
In the summer of 1961, Bob Blacker left St. Rita's High School to work for the Federal Aviation Administration (FAA) in Washington, DC. Blacker incorporated Project Schoolflight into the U.S. Department of Transportation/FAA guidelines as an approved educational program.
Project Schoolflight started winding down soon after the delivery of the Wright Flyer replica to the EAA Museum in 1978. However, the project served as a forerunner for EAA's follow-on Young Eagles program.
Young Eagles program
In the 2001 Annual Report to EAA Members, Tom Poberezny, Paul's son and then CEO of EAA, remarked: "As we focus on Sport Pilot and Light Sport Aircraft, we will continue to address our core programs built around homebuilder aircraft education ... the important part of the future is educational outreach programs. They started in 1956 at St. Rita High School with [Project Schoolflight...by Robert Blacker] and his students. That was a showcase initiative that touched a few kids deeply, but we wanted to do more".
Because of the EAA's policies on youth education, many prominent educators visited EAA Headquarters to study the Schoolflight program. In 1992, Tom Poberezny founded the EAA's Young Eagles program, giving children their first flight in a light aircraft. The Young Eagles program would serve to transition the youths of EAA from homebuilding planes to introducing them to flying and encouraging them to become pilots.
References
External links
First Short Snorter in EAA History presented to Robert D. Blacker for his efforts on Project Schoolflight
Experimental Aircraft Association | Project Schoolflight | [
"Engineering"
] | 1,405 | [
"Experimental Aircraft Association",
"Aerospace engineering organizations"
] |
67,829,300 | https://en.wikipedia.org/wiki/Quinolidomicin | Quinolidomicin A1 is a 60-membered macrocyclic compound isolated from Micromonospora sp. JY16. Quinolidomicins are a class of macrolides that contain a benzoquinone chromophore as well as an immense lactone ring, which far surpasses that in monozanomycin. It is currently the largest identified macrolide of terrestrial origin. It was initially discovered when in a screening for anti-tumor antibiotics, where it was found to be cytotoxic against P388 murine leukemia cells (IC50 8 nM), and has later been found to have strong cytotoxic activity against HT-29, MKN28, K562, and KB.
Biosynthesis
Like many macrocyclic polyketides, quinolidomicin A1 is biosynthesized by type-I polyketide synthases. Decarboxylative condensations for a single-chain elongation are facilitated by β-ketosynthase (KS), acyl transferase (AT), and acyl carrier protein (ACP). The modification domains that contribute to structural variations are dehydratase (DH), enoylreductase (ER), and β-ketoreductase (KR). A module refers to a set of these domains. The acyclic chain is then cut by thioesterase (TE). As this is such a large macrolide, it contains many modules across 13 open reading frames (ORF) to be biosynthesized, the order shown as a sequence of these domains.
References
Macrocycles
Oxygen heterocycles
Heterocyclic compounds with 2 rings | Quinolidomicin | [
"Chemistry"
] | 372 | [
"Organic compounds",
"Macrocycles"
] |
67,829,818 | https://en.wikipedia.org/wiki/Blum%E2%80%93Ittah%20aziridine%20synthesis | The Blum–Ittah aziridine synthesis, also known as the Blum–Ittah-Shahak aziridine synthesis or simply the Blum aziridine synthesis is a name reaction of organic chemistry, for the generation of aziridines from oxiranes.
Mechanism
The oxirane is first converted into a 2-azidoalcohol with the use of an azide such as sodium azide. The azido alcohol is then reduced with the use of a trialkylphosphine such as triphenylphosphine in a manner similar to the Staudinger reaction, concomitant with loss of N2. The resulting phosphanimine (formerly called iminophosphorane) intermediate is then attacked by the alcohol, with oxygen forming a bond with the phosphorus atom. Forming a ring intermediate. After a proton transfer, a pair of electrons from the oxygen atom shifts onto the phosphorus atom, and the phosphorus-nitrogen bond breaks, with the electron pair shifting onto the nitrogen atom. The negatively charged nitrogen atom attacks the carbon atom that the oxygen atom is connected to. This gives us our desired aziridine and a trialkylphosphine oxide as a side product.
Applications
The Blum-Ittah aziridine synthesis has been used in the synthesis of α-methylserine and 6-Azabicyclo[3.2.1]octanes.
References
Name reactions
Nitrogen heterocycle forming reactions | Blum–Ittah aziridine synthesis | [
"Chemistry"
] | 305 | [
"Name reactions",
"Chemical reaction stubs",
"Ring forming reactions",
"Organic reactions"
] |
67,830,819 | https://en.wikipedia.org/wiki/Chiral%20inversion | Chiral inversion is the process of conversion of one enantiomer of a chiral molecule to its mirror-image version with no other change in the molecule.
Chiral inversion happens depending on various factors (viz. biological-, solvent-, light-, temperature- induced, etc.) and the energy barrier energy barrier associated with the stereogenic element present in the chiral molecule. 2-Arylpropionic acid nonsteroidal anti-inflammatory drugs (NSAIDs) provide one of the best pharmaceutical examples of chiral inversion. Chirality is attributed to a molecule due to the presence of a stereogenic element (viz. center, planar, helical, or axis). Many pharmaceutical drugs are chiral and have a labile (configurationally unstable) stereogenic element. Chiral compounds with stereogenic center are found to have high energy barriers for inversion and generally undergo biologically mediated chiral inversion. While compounds with helical or planar chirality have low energy barriers and chiral inversions are often caused by solvent, light, temperature. When this happens, the configuration of the chiral molecule may rapidly change reversibly or irreversibly depending on the conditions. The chiral inversion has been intensively studied in the context of the pharmacological and toxicological consequences. Other than NSAIDs, chiral drugs with different chemical structures can also show this effect.
Chiral drugs have different effects on the body depending on whether one enantiomer or both enantiomers act on different biological targets. As a result, chiral inversion can change how a pharmaceutical drug works in the body. From a pharmacological and toxicological point of view, it is very important to learn more about chiral inversion, the things that make it happen, and the tools used to figure out chiral inversion.
Types
Essentially there are two types of chiral inversion, unidirectional and bidirectional. Inversion process is dependent on species and substrate.
Unidirectional chiral inversion (enzyme mediated) was described only with 2-arylpropionate nonsteroidal anti-inflammatory drugs (NSAIDs), namely ibuprofen, ketoprofen, fenoprofen, benoxaprophen, etc. For this group, only S-enantiomer (eutomer) is active i.e. has analgesic and anti-inflammatory effect. In the body, only inactive R-enantiomer can undergo chiral inversion by hepatic enzymes into the active S-enantiomer and not vice versa. The “inactive” R-isomer (distomer) may be responsible for the gastrointestinal irritation and related side-effects associated with NSAIDs. In certain situations, carbenicillin, ethiazide, etoposide, zopiclone, pantoprazole, clopidogrel, ketorolac, albendazole-sulfoxide, lifibrol, and 5-aryl-thiazolidinedione also go through unidirectional chiral inversion. Chiral inversions were found to happen in a group of important compounds called α-amino acids. Amino acids exist in two mirror-image versions (D- and L- configurations). Several D-amino acids, like D-methionine, D-proline, D-serine, D-alanine, D-aspartate, D-leucine, and D-phenylalanine, have been shown to go through unidirectional chiral inversion in mammals.
Bidirectional chiral inversion or racemization type of inversion is shown by pharmaceutical drugs including 3-hydroxy-benzodiazapine class of drugs (oxazepam, lorazepam, temazepam), thalidomide, and tiaprofenic acid. A brief list of select pharmaceutical drugs that go through chiral inversion are presented in Table below..
Mechanism
It is well documented that (R)-enantiomers of profens in the presence of coenzyme A (CoA), adenosine triphosphate (ATP) and Mg+2 are converted to active (S)-forms. The pathways of chiral inversion is illustrated taking ibuprofen as the prototype, in the scheme below.
The pathway consists mainly of three steps:
Stereoselective activation: Stereoselective activation of (R)-profen by the formation of the thioester, in the presence of CoA, ATP and Mg+2. (S)-profen does not form the thioester.
Epimerization (Racemization): The enzyme epimerase 2-arylpropionic-CoA changes the (R)-thioester to the (S)-thioester. This process is called "racemization" or "epimerization."
Hydrolysis: With the help of hydrolase/thioesterase, thioesters are broken down into their (R)- and (S)-forms
Because the acyl-CoA thioester (profenyl-CoA) changes the structure of triglycerides and phospholipids, metabolic chiral inversion may cause toxic effects.
Factors influencing inversion
Chiral drugs with stereo-labile configuration are likely to undergo interconversion of the enantiomers that may be enzymatic (biological) or non-enzymatic. Enzyme-mediated conversion is the process of chiral inversion that happens in a living organism. Non-enzymatic inversion of drugs is important and relevant in the pharmaceutical manufacturing process. This may have impact on the shelf-life of a drug and the economic feasibility of the resolution. Inversion can also happen without enzymes when precolumn derivatization is used in enantioselective chromatographic separation techniques. Racemization can also happen in the acidic environment of the stomach and other bodily fluids.
Enzyme-mediated (biological)
Enzyme-mediated (biological) chiral inversion of organic compounds is caused by highly chiral endogenous molecules found in receptors, enzymes, and other structures. While enzyme inhibitors suppress enzyme activity, enzyme inducers boost enzyme concentration and activity. The primary determinants of inter-individual variability in drug metabolism in humans are thought to include genetic polymorphism and a variety of other variables, including age, gender, biological conditions, pregnancy, illnesses, stress, nutrition, and drugs. For instance, Reichel et al. reported that a 2-arylpropionyl-coenzyme-A epimerase was molecularly cloned and expressed as a crucial enzyme in the inversion metabolism of ibuprofen. Ibuprofen's chiral inversion by enzymes has been documented in humans.
Species differences
Tissue variations
The liver, gastrointestinal tract (GIT), lungs, kidney, and brain are among the tissues that participate in the chiral inversion of medicines. The liver has been shown to be the most crucial organ in the development of this mechanism. Although some studies contend that rat liver homogenates lack the enzymatic mechanisms necessary to invert the R-enantiomers of flurbiprofen, naproxen, suprofen, and ibuprofen, the liver may also be involved in the inversion of R-ibuprofen in rats. On the other hand, it was noted that certain medicines underwent chiral inversion without the involvement of the liver (hepatocytes). Although liver did not play a substantial role in the inversion of benoxaprofen, studies using benoxaprofen and ketoprofen show that one of the primary sites of inversion in rats is the GI tract.
Route of administration
Inter-individual variability
Non-enzymatic
Sample handling and manufacturing process
Temperature and pH
Analytical methods
Chiral inversion is a very important part of designing and making drugs. Because this process can change how chiral drugs work in the body and can cause side effects that can be serious or even fatal. Traditionally, chiral inversions have been studied with NMR spectroscopy at different temperatures and chiroptical methods like polarimetry. But strong, complementary methods based on dynamic chromatography (GC, HPLC, SFC, CEC, and MEKC) and electrophoresis have been made and used to figure out how the enantiomeric composition of stereo-labile chiral compounds changes over time. Most of the time, liquid chromatographic methods are used to do enantioselective analysis of chiral drugs. When an analyte with one stereogenic center or axis is separated well, the chromatogram will show two peaks. But if the analyte is stereo-labile, the peaks tend to merge. How much coalescence there is will depend on how fast chiral inversion and enantioresolution happen. Over time, the peaks will merge into a flat area. Dynamic chromatography shows how the elution profile changes over time. This makes it useful for figuring out how pH, temperature, and solvents affect chiral inversion, which can happen on the stationary phase, in the injector, or in the detector.
Multidimensional approaches have been used to improve separation and detection. Table below shows a list of common methods and experiments used to figure out chiral inversion. Any of these methods can then be used to determine chiral inversion. Which instrument is used to analyze a chiral compound depends on its physical and chemical properties (i.e., the solubility, vapor pressure, thermal and solvent stability, and detection).
For example, capillary electrophoresis or liquid chromatography could be used if the analyte can be ionized and has a high vapor pressure, but it is also soluble in polar solvents. On the other hand, gas chromatography is the best way to test a substance that is stable at high temperatures but has a low vapor pressure. When compared to gas or liquid chromatography, supercritical fluid chromatography is a better way to measure chiral inversion because it uses mass spectrometers and a green method.
Significance in drug development
Enantiomers of a chiral drug often interact in an enantioselective way in a chiral environment. This may be offered by different biotic substances (viz. proteins, nucleic acids, phospholipids and oligosaccharides). They are made up of chiral building blocks that are put together in space in handed conformations. These biological targets function as receptors for the drug enantiomers. So, at the binding sites of these receptors, enantiomers will be seen as different chemical species. The three point attachment model (Easson & Stedman model) can be used to see how chiral discrimination works. Figure depicts how the enantiomers of a drug interact with receptors in a way that depends on the drug's shape.
This model was made for chiral drugs with a single stereogenic center. It says that there are three binding sites in the receptor (B', C' and D') that match the drug's pharmacophoric groups (B, C, D). A three-point fit (good fit) is possible for the eutomer at BB', CC' and DD'(Fig. A). Even though the distomer is the wrong enantiomer, it can fit either a one-point interaction (bad fit), or a two-point attachment (CC' and DD') with the same receptor site as shown in (Fig. B).
Eutomer is the version that works the way you want it to, and distomer is the version that doesn't work or works in a way you don't want it to. Most of the time, the mirror-image versions have different binding affinities. In the eutomer, the ligands or moiety around a stereogenic element have more binding energy than in the distomer. When the eutomer goes through chiral inversion, it loses its ability to bind to a biological receptor. Because of these enantiospecific interactions, therapeutic and toxicological properties are enantioselective So, the stereo-stability of chiral drugs may have big effects on the process of making new drugs, especially when it comes to how pharmaceutical, pharmacokinetic, and pharmacodynamic information is read and understood. At every stage of designing, making, and testing a drug for safety, chiral inversion must be taken into account.
See also
Ibuprofen
Dexibuprofen
Ketoprofen
Thalidomide
Fenoprofen
Chiral drugs
Chiral switch
References
External links
Chirality
Enantiopure drugs
Stereochemistry | Chiral inversion | [
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"Chemistry",
"Biology"
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"Enantiopure drugs",
"Chirality",
"Space",
"nan",
"Asymmetry",
"Biological hypotheses",
"Spacetime",
"Symmetry"
] |
67,831,655 | https://en.wikipedia.org/wiki/MATHUSLA | MATHUSLA (MAssive Timing Hodoscope for Ultra-Stable neutraL pArticles) is a proposed experiment at CERN's Large Hadron Collider (LHC). It is a dedicated large-volume detector on the surface above CMS for exotic long-lived particles (LLPs) produced in LHC collisions, which can travel to the surface and decay into charged particles inside its decay volume. MATHUSLA is motivated by the fact that LLPs could easily escape detection in the existing LHC experiments (the ATLAS experiment, CMS and LHCb), but their existence could explain major outstanding questions in particle physics, like possibly the hierarchy problem, dark matter, baryogenesis or the masses of neutrinos. MATHUSLA's location on the surface, shielded from the radiation of LHC collisions that can obfuscate LLP signals, as well as its large detection volume allows it to fill this capability gap and detect LLPs with very long lifetimes up to the ~0.1 second upper limit imposed by Big Bang nucleosynthesis.
The project is supported by an international collaboration and is in the technical development phase, with operations planned to start in the mid-to-late 2020s.
References
Large Hadron Collider
E-Science
Physics beyond the Standard Model | MATHUSLA | [
"Physics"
] | 267 | [
"Unsolved problems in physics",
"Particle physics",
"Physics beyond the Standard Model"
] |
67,834,099 | https://en.wikipedia.org/wiki/May%202107%20lunar%20eclipse | A penumbral lunar eclipse will occur at the Moon’s ascending node of orbit on Saturday, May 7, 2107, with an umbral magnitude of −0.9356. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into the Earth's penumbra. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. The Moon's apparent diameter will be near the average diameter because it will occur 6.8 days after perigee (on April 30, 2107, at 10:00 UTC) and 6.9 days before apogee (on May 14, 2107, at 1:50 UTC).
This eclipse will be too small to be visually perceptible.
Visibility
The eclipse will be completely visible over much of North and South America, western Europe, west and southern Africa, and Antarctica.
Eclipse details
Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.
Eclipse season
This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight. The first and last eclipse in this sequence is separated by one synodic month.
Related eclipses
Eclipses in 2107
A penumbral lunar eclipse on April 7.
An annular solar eclipse on April 23.
A penumbral lunar eclipse on May 7.
A penumbral lunar eclipse on October 2.
A total solar eclipse on October 16.
Metonic
Preceded by: Lunar eclipse of July 19, 2103
Tzolkinex
Followed by: Lunar eclipse of June 18, 2114
Lunar Saros 152
Followed by: Lunar eclipse of May 17, 2125
Inex
Followed by: Lunar eclipse of April 16, 2136
Triad
Preceded by: Lunar eclipse of July 5, 2020
Followed by: Lunar eclipse of March 7, 2194
Lunar eclipses of 2103–2107
This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.
The penumbral lunar eclipses on January 23, 2103 and July 19, 2103 occur in the previous lunar year eclipse set, and the penumbral lunar eclipses on April 7, 2107 and October 2, 2107 occur in the next lunar year eclipse set.
Metonic series
See also
List of lunar eclipses
List of 22nd-century lunar eclipses
References
2107-05
2107-05 | May 2107 lunar eclipse | [
"Astronomy"
] | 628 | [
"Future astronomical events",
"Future lunar eclipses"
] |
67,834,111 | https://en.wikipedia.org/wiki/Ameristar%20Charters%20Flight%209363 | Ameristar Charters Flight 9363 was a charter flight from Willow Run Airport to Washington Dulles Airport on March 8, 2017, which rejected takeoff and overran the runway. The crash was caused by a jammed elevator, which was damaged by high winds the day before the crash.
All 116 passengers and crew survived the crash, with only one minor injury, but the aircraft was damaged beyond repair. The NTSB investigation found that the elevator was damaged while the aircraft was parked, and then was not noticed due to flaws in the aircraft's design and Ameristar's operating procedures.
Accident
The aircraft had been chartered to transport the Michigan Wolverines men's basketball team to the Big Ten tournament in Washington, D.C. for the following day's game against the Illinois Fighting Illini. Prior to the flight, the aircraft had been parked at Willow Run Airport since it arrived from Lincoln Airport in Lincoln, Nebraska on March 6.
Hours before the accident, the air traffic control tower at Willow Run Airport had been evacuated due to high winds. The windstorm affected much of Southeast Michigan, and resulted in power outages for over 800,000 DTE customers. A power outage at Willow Run disabled most of the weather instrumentation in the airport's automated surface observing system (ASOS), and manual weather observations were also unavailable due to the evacuation of the control tower.
As a result, the flight crew of Flight 9363 obtained weather information from alternate sources, contacting company operations personnel for a temperature setting, and calling the nearby Detroit Metropolitan Airport on one of the pilots' cell phones to get the current weather information at the latter airport. Lacking information from the ASOS, the crew used windsocks at the airport to determine the predominant wind direction and inform their choice of runway. The flight crew modified their planned takeoff to protect against the danger of wind shear, selecting a higher rotation speed than would otherwise be prescribed.
The flight was delayed slightly, due to the communication difficulties caused by the power outages at the airport. Flight 9363 taxied uneventfully to runway 23L, and received its takeoff clearance from Detroit Metropolitan via cell phone due to the lack of ATC services at Willow Run. The check airman acting as pilot in command, 41-year-old Andreas Gruseus, directed the captain, 54-year-old Mark Radloff, to begin the takeoff roll, which began at 14:51:12 EST. The takeoff roll was normal until rotation speed (VR), at indicated airspeed (KIAS). At VR, when the captain pulled back on the control column to rotate the aircraft, the aircraft failed to respond, even after the captain applied additional back force to the control column. Judging the aircraft to be incapable of flight, the captain performed a rejected takeoff, immediately applying maximum braking followed by spoilers and reverse thrust.
By the time the captain rejected the takeoff, the aircraft had accelerated to , over above the decision speed (V1), and was moving too fast to stop in the remaining runway distance. The aircraft ran off the end of the runway and across the grassy runway safety area (RSA), before striking the raised pavement of an access road along the airport perimeter. Upon striking the road pavement, the aircraft's landing gear collapsed, and the aircraft slid on its belly over the road and a ditch just beyond, causing substantial damage to the belly and underside of the nose. The aircraft came to a stop with its empennage on the road and its nose in a grassy field on the far side of the road and ditch.
An orderly, rapid evacuation followed. The aircraft had 8 emergency exits, of which 4 were used. One emergency exit was rendered unusable by a faulty evacuation slide, and another was blocked by a seatbelt stuck in the door. All 110 passengers and 6 crew members survived the crash, with one injury, a passenger who suffered a laceration to the leg.
Aircraft
The aircraft involved was a McDonnell Douglas MD-83 (DC-9-83), registration N786TW, manufacturer serial number (MSN) 53123, line number 1987. Constructed at Long Beach Airport, it was first delivered to Avianca on 14 April 1992 on lease from GECAS with Irish registration EI-CEQ. Between 2005 and 2006, it was named Ciudad de Leticia. It was painted in the Juan Valdez special livery in December 2007. It was registered in Colombia as HK-4589X on 26 March 2010. It was purchased by Ameristar on 17 December 2010, registered in the United States as N786TW. It was damaged beyond repair in the accident and written off aged 25 years.
Investigation
Aircraft design
The crash occurred after the aircraft failed to rotate upwards, and the investigation focused on the aircraft's elevator system as a cause of the failure. The elevators of the MD-80 series aircraft are controlled indirectly via a system of servo tabs, using a design similar to the MD-80's predecessor, the DC-9.
During a normal takeoff in an MD-80 aircraft, the pilot rotates the aircraft off the runway by pulling the control column back (aft), which moves the elevator control tab into a trailing-edge-down (TED) position. The elevator control tab directs airflow around the elevator, and causes lift from forward airflow to move the elevators in the opposite direction of the tab. The elevator is in turn linked to two more servo tabs, including a geared tab that provides mechanical advantage to the pilot's control inputs. During takeoff, the pilot's commands through the control column, via the system of three servo tabs, ultimately moves the elevator into a trailing-edge-up (TEU) position. This affects the pitch angle of the aircraft, and rotates it up and off the runway.
As a consequence of this design, the elevators are not able to be moved during a typical preflight inspection, when the aircraft is stationary and there is no airflow over the elevators. A more thorough inspection of the elevators involves moving them by hand, but it requires a scissor lift (or similar equipment) to reach the top of the T-tail in the air, and is not typically performed during a preflight inspection.
Another consequence of the elevator system design is that when the aircraft is parked, the elevators move freely with the wind, within limits. The MD-80 is not equipped with a gust lock, which would prevent this motion. The range of motion of the elevator is constrained by stops, which are equipped with shock absorbers for protection. This system is designed to withstand high-speed airflow from straight ahead during flight, but strong forces from other directions can overcome the shock absorbers. If the linkages in the geared tab move too far, they can become "overcentered," jamming the elevator in place. The MD-80 was designed to withstand horizontal wind gusts of up to from any direction while on the ground.
Postaccident condition of the control systems
When the aircraft was inspected on site following the accident, the right elevator was found to be jammed in a full trailing-edge-down (TED) position slightly beyond its normal limit of motion, and could not be moved by hand. The inboard control linkage of the right elevator's geared tab was damaged, being locked in an overcenter position, beyond its normal limit of travel, and with portions of the control linkage bent and displaced outboard. When the damaged linkage was disconnected by investigators, the elevator could be freely moved by hand from stop to stop. The cockpit controls could be moved throughout their full range of motion, and the control tabs were observed to move properly in response to control column inputs.
Company policies and maintenance
Ameristar's procedures were intended to protect aircraft from damage to flight controls from high winds. Per company policy, aircraft stored outside in winds of over 60 knots had to be parked facing into the wind. If aircraft had been exposed to wind gusts in excess of 65 knots from other than straight ahead while parked, a physical inspection of all flight control surfaces would have been required, including a check confirming that the control surfaces were free to move. Measurement equipment at Willow Run recorded maximum wind gusts of , below both thresholds.
A review of elevator-position data from the aircraft's flight data recorder (FDR) showed that the right elevator moved properly on the morning of March 6, during a maintenance check. By the next time the aircraft was powered up, at 12:38 on the day of the accident, the right elevator was already at the full trailing-edge-down position, and remained there in all elevator-position data recorded during the preparations for the flight to Dulles. In contrast, the left elevator moved several times throughout its full range of motion under the influence of ground winds. During the attempted takeoff, the left elevator followed the captain's commands, but the right elevator remained in the full trailing-edge-down position until partway through the attempted rotation, and then only moved slightly.
Prior elevator jam incident (Munich, 1999)
Prior to the Flight 9363 accident, the aircraft manufacturer had record of only one wind-induced elevator jam on any DC-9-series aircraft, which occurred at Munich Airport, Germany, in December 1999, and involved exposure to winds exceeding the elevator system's design limits.
In that incident, the airport had been subjected to a severe windstorm while the incident aircraft (another MD-83) was on the ground, with peak winds of up to . This exceeded the manufacturer's mandatory inspection limits for the DC-9/MD-80 flight control system, and the flight crew requested an inspection of the aircraft's flight control system. A full inspection of the aircraft's elevators, which would have involved moving the elevators by hand, was not conducted due to personnel-safety concerns in the continuing high winds. Instead, maintenance personnel had the flight crew perform a flight control check by moving the control column throughout its entire range of motion and checking for any abnormal resistance. No abnormalities were detected during this check, and the aircraft was released for flight. The aircraft was unable to rotate off the runway, and the flight crew were forced to reject the takeoff at very high speed. In this instance, the aircraft was safely brought to a stop on the runway.
The German Federal Bureau of Aircraft Accident Investigation (BFU) found that the Munich aircraft's left elevator was jammed in a full trailing-edge-down position, having been forced into that position by the high winds experienced on the ground. Boeing, as recommended by the BFU, instituted new procedures for DC-9, MD-80, and Boeing 717 operators, requiring inspections of elevator systems after aircraft were exposed to high winds on the ground. The threshold set was without the aircraft's nose pointed into the wind, and the requirements following exposure to winds below this threshold remained unchanged.
Wind field analysis and load testing of elevator system
The aircraft in the Ameristar 9363 incident was damaged in the same way as the aircraft in Munich, but it was not subject to winds nearly as strong. Investigators identified a hangar immediately upwind of the aircraft's parking position as a potential cause of wind conditions that could have affected the aircraft. The investigators performed computational fluid dynamics (CFD) modeling of the wind field downwind of the hangar and around the parked aircraft, using a detailed three-dimensional model of the hangar obtained via drone imagery.
The CFD analysis showed that the hangar had a significant impact on the local winds at the parked aircraft. A horizontal gust passing over the hangar was found to produce a 58-knot gust at the aircraft itself. The hangar also introduced significant turbulence, which produced vertical forces. These forces could slam the aircraft's elevators forcefully between their stops, potentially resulting in flight-control damage.
To determine whether this theory was possible, the NTSB performed a series of static and dynamic load tests on the accident aircraft's undamaged horizontal stabilizers and left elevator. The tests, conducted at a Boeing laboratory in Huntington Beach, California, simulated the wind conditions calculated by the CFD analysis. The static tests consisted of hanging weights from the elevator while in its trailing-edge-down position, simulating constant wind speeds. Static testing resulted in no damage to the geared tab linkage (the damaged component of the accident aircraft), even at wind speeds of up to .
The dynamic load tests simulated turbulence in the wind flow by lifting the elevator and dropping it. The investigators used the same quantity of weight as the static tests, simulating the same horizontal wind speeds with more fluctuation of vertical wind speed. A simulated 60-knot gust applied to the elevator in its full trailing-edge-up position, slamming down to its full TED position, was sufficient to overcenter the geared tab linkage. A simulated 70-knot gust was able to achieve similar effects from the elevator's neutral position.
As a final test, with the inboard geared-tab linkage of the test elevator locked in an overcenter position, a TEU force was applied to the elevator using the forklift, simulating the conditions during the takeoff roll. The overcentered links failed and bent outboard, in the same manner as the right elevator did during the takeoff roll.
Probable cause
The NTSB released their final report in February 2019, which concluded that
Pilots' actions
The report praised the actions of the flight crew for contributing to the lack of serious injuries or fatalities in the accident. In a press release on March 7th, NTSB chairman Robert Sumwalt stated "This is the kind of extreme scenario that most pilots never encounter – discovering that their plane won't fly only after they know they won't be able to stop it on the available runway. These two pilots did everything right after things started to go very wrong."
Aftermath
The morning after the crash, the Wolverines men's basketball team traveled to Washington on the Detroit Pistons team plane. The team arrived at the Verizon Center in Washington at 10:30 AM, in time for their noon game against Illinois. The Wolverines played the game in their practice uniforms, as the team's luggage was still on the crashed plane. The Wolverines won against Illinois, 7555, and went on to win the Big Ten tournament. Following their Big Ten tournament victory, the Wolverines advanced in the NCAA tournament, reaching the Sweet Sixteen round before losing to Oregon on March 24.
Legacy
In response to the crash, Boeing developed a modification to the DC-9 elevator system, which would add a second stop to the elevator system. This secondary stop would physically prevent the elevator from moving far enough past its limits to allow the geared-tab linkages to become locked in an overcenter configuration. For DC-9s with tab-driven elevators not yet equipped with the secondary elevator stop, including DC-9s, MD-80s, and 717s, the maintenance manual was revised to decrease the wind strengths which would necessitate a physical inspection of the elevator system before further flight. The NTSB recommended that Boeing finalize and fully implement these changes, and also develop a means for DC-9 flight crews to detect an elevator jam before attempting to take off.
See also
2021 Houston MD-87 crash, an MD-80 runway excursion that resulted in the total destruction of the aircraft due to flight-control damage similar to Flight 9363
Notes
References
External links
NTSB accident report (summary, PDF)
NTSB investigation docket (archive)
Accident description at the Aviation Safety Network (archive)
Aviation accidents and incidents in 2017
Aviation accidents and incidents in Michigan
Airliner accidents and incidents caused by mechanical failure
Airliner accidents and incidents involving runway overruns
Aviation accidents and incidents involving sports teams
Accidents and incidents involving the McDonnell Douglas MD-83
2017 in Michigan
Michigan | Ameristar Charters Flight 9363 | [
"Materials_science"
] | 3,241 | [
"Airliner accidents and incidents caused by mechanical failure",
"Mechanical failure"
] |
67,834,167 | https://en.wikipedia.org/wiki/Ibrexafungerp | Ibrexafungerp, sold under the brand name Brexafemme, is an antifungal medication used to treat vulvovaginal candidiasis (VVC) (vaginal yeast infection). It is taken orally (by mouth). It is also currently undergoing clinical trials for other indications via an intravenous (IV) formulation. An estimated 75% of women will have at least one episode of VVC and 40 to 45% will have two or more episodes in their lifetime.
Ibrexafungerp acts via inhibition of glucan synthase, which prevents formation of the fungal cell wall.
Ibrexafungerp was approved for medical use in the United States in June 2021. It is the first non-azole oral antifungal drug to be approved by the U.S. Food and Drug Administration (FDA) for the treatment of vaginal yeast infections. The FDA considers it to be a first-in-class medication.
Medical uses
Ibrexafungerp is indicated for the treatment of adult and postmenarchal pediatric females with vulvovaginal candidiasis (VVC).
Ibrexafungerp is currently undergoing late-stage clinical trials for an intravenous formulation for the treatment of various fungal diseases, including life-threatening fungal infections caused primarily by Candida (including C. auris) and Aspergillus species. It has demonstrated broad-spectrum antifungal activity, in vitro and in vivo, against multidrug-resistant pathogens, including azole- and echinocandin-resistant strains.
Pharmacology
Pharmacodynamics
Ibrexafungerp is a triterpenoid antifungal agent. It acts via inhibition of the enzyme glucan synthase, which is involved in the formation of 1,3-β-D-glucan—an essential component of the fungal cell wall. The compound has concentration-dependent fungicidal activity against Candida species.
Pharmacokinetics
Ibrexafungerp has a time to maximal concentrations of 4 to 6hours. It is metabolized by hydroxylation via CYP3A4 and subsequently by glucuronidation and sulfation. The medication has an elimination half-life of approximately 20hours.
Synthesis
References
Further reading
External links
Amino acids
Antifungals
Heterocyclic compounds with 5 rings
Oxygen heterocycles
4-Pyridyl compounds
Triazoles | Ibrexafungerp | [
"Chemistry"
] | 524 | [
"Amino acids",
"Biomolecules by chemical classification"
] |
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