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73,378,834 | https://en.wikipedia.org/wiki/Leith%20AGCM | Leith AGCM is a climate model that was developed by Cecil Leith beginning in 1958 and probably is the oldest atmospheric general circulation model. Leith published videos of its model output, inspiring other scientists to do the same. Today it has been superseded by climate models developed from different base codes and is little known.
History and development
Efforts to calculate the behaviour of the weather system commenced in the 1920s with a seminal paper by Lewis Fry Richardson. By the 1950s and 1960s several groups were involved in making climate models, with major efforts taking place at several US universities that eventually gave rise to the well-known GFDL, UCLA, and NCAR models. Today climate models are an important enterprise with significant impact on public policy, where hundreds of scientists and institutions participate worldwide.
The researcher Cecil E. “Chuck” Leith (1923–2016) is well-known for his research on fluid mechanics. After an initial career on the Manhattan Project, which resulted in the invention of nuclear bombs, he joined the Lawrence Radiation Laboratory after 1946 and in 1968 the National Center for Atmospheric Research. Beginning in 1958, he began to work on a climate model that was later named the "Leith atmospheric model" or "Livermore atmospheric model". Its existence was barely reported at that time, with only several contemporary journal articles mentioning it. According to interviews with Leith, he was inspired to work on climate modelling by the noted scientist Edward Teller and by the idea to put his knowledge on nuclear explosions to use in a field that wouldn't be hindered by nuclear test bans. The model was written in assembly language, which may have given it a headstart compared to other climate model projects that were undergoing in Livermore at the time and which relied on compiler language. There appear to have been four versions, based on reports of improvement work on the code, and Leith publicized numerous videos (at the time called "movies") of the output of his model. Today, the readable presentation of the often enormous quantities of data output by climate models is a major problem in climate modelling; and Leith's example inspired other scientists to make videos as well. Leith apparently relied on a private company, Pacific Title, which worked in the entertainment industry at Hollywood, and one video displaying the output of hid model.
The model
This model, which was apparently created single-handedly by Leith, included initially five, later six, elevation levels in the atmosphere and a realistic land-sea distribution, with the entire model covering the latitudes between the equator and 60° north on a 5° grid. Later its scope was broadened to the polar regions. It included parametrized drag, eddy diffusion, radiative processes but no topography. It could simulate the day-night temperature cycle but did not yield realistic precipitation distribution even after improvement work. Later versions were used to simulate the climate of Mars and the behaviour of the Arctic during the ice ages.
Significance
Leith twice claimed that his model was the first to include a simulated hydrological cycle. There are other earlier models discussed in the literature, but only little evidence that they were actually operative; it is not clear when hydrological cycles began to be included in climate models but it appears that it was after the Leith model. The model was however only once used in an academic publication, specifically in a 1968 publication about atmospheric tides, as Leith's interest shifted to two dimensional turbulence, and ultimately his model proved much less influential than other climate modelling efforts.
References
Sources
External links
History of science
Climate modeling | Leith AGCM | [
"Technology"
] | 705 | [
"History of science",
"History of science and technology"
] |
56,288,945 | https://en.wikipedia.org/wiki/Ilijas%20Farah | Ilijas Farah (born 18 February 1966) is a Canadian-Serbian mathematician and a professor of mathematics at York University in Toronto and at the Mathematical Institute of Serbian Academy of Sciences and Arts, Belgrade, Serbia. His research focuses on applications of logic to operator algebras.
Career
Farah was born in Sremska Mitrovica, Serbia. He received his BSc and MSc in 1988 and 1992 respectively from Belgrade University and his PhD in 1997 from the University of Toronto.
He is a Research Chair in Logic and Operator Algebras at York University, Toronto. Before moving to York University he was an NSERC Postdoctoral Fellow, York University (1997–99), a Hill Assistant Professor at Rutgers University (1999–2000), and a professor at CUNY–Graduate center and College of Staten Island (2000–02).
Farah was an invited speaker at the International Congress of Mathematicians, Seoul 2014, section on Logic and Foundations, where he presented his work on applications of logic to operator algebras.
Awards, distinctions, and recognitions
Sacks prize for the best doctorate in Mathematical Logic, 1997
Governor General's gold medal for one of the two best doctorates at the University of Toronto, 1998
The Canadian Association for Graduate Studies/University Microfilms International Distinguished Dissertation Award, for the best dissertation in engineering, medicine and the natural sciences in Canada, 1998.
Dean's award for outstanding research, York University, 2006.
Faculty Excellence in Research Award (Established Research Award), Faculty of Science, York University, 2017
Sources
External links
Ilijas Farah: Krajnja proširenja modela, MSc thesis, Belgrade university 1992.
Living people
Canadian mathematicians
Mathematical logicians
Set theorists
1966 births
Yugoslav emigrants to Canada
Canadian people of Serbian descent | Ilijas Farah | [
"Mathematics"
] | 358 | [
"Mathematical logic",
"Mathematical logicians"
] |
56,289,620 | https://en.wikipedia.org/wiki/Geum%20%C3%97%20catlingii | Geum × catlingii, or Catling's avens, is a plant in the rose family, Rosaceae. It is known from eastern Canada, where it arises from natural hybridization between the native G. canadense Jacq. and the introduced G. urbanum L. It is named after Paul M. Catling, the botanist who first observed the hybrid.
Description
Geum ×catlingii is a hybrid taxon, and as such exhibits variable morphology. However, several characters in combination help distinguish it from other Geum species:
Hybrid vigor - hybrids tend to be larger than parents
Petals are creamy-yellow - intermediate between dark yellow (G. urbanum) and white (G. canadense).
Intermediate stem bract size
Highly sterile ovaries
It has been noted to bloom throughout the summer, after other species have shed their petals.
References
catlingii
Hybrid plants
Flora of Northern America
Plants described in 1986 | Geum × catlingii | [
"Biology"
] | 193 | [
"Hybrid plants",
"Plants",
"Hybrid organisms"
] |
56,290,385 | https://en.wikipedia.org/wiki/HD%20163840 | HD 163840 is a binary star system in the northern constellation of Hercules. It has a combined apparent visual magnitude of 6.45, which falls just below the brightness level that is visible to the naked eye for people with normal eyesight. An annual parallax shift of 35.40 mas provides a distance estimate of about 92 light years. The system is moving closer to the Sun with a radial velocity of −33 km/s. In about 769,000 years, it will make perihelion at a separation of around .
R. K. Young of the Dominion Astrophysical Observatory was the first to recognize the variable radial velocity of this system. In 1974, Harold A. McAlister and Philip A. Ianna identified it as a nearby G-type dwarf based on its spectroscopic properties. McAlister et al. (1974) found it to be a spectroscopic binary and the components were first resolved in 1976. A series of observations since that time allowed the system's orbital elements to be published by McAlister et al. (1995), along with estimates of the stellar masses of the two components. These parameters have been further refined using improved instruments up through 2016.
The pair of stars orbit each other with a period of and an eccentricity of 0.417. The plane of their orbit is inclined by an angle of 73° to the line of sight from the Earth, with a semimajor axis having an angular value of 80.64 mas. The close, eccentric orbit of the pair does not permit a stable planetary orbit in the habitable zone of either component.
The primary, component A, is a magnitude 6.30 G-type main-sequence star with a stellar classification of G2 V. It has 1.13 times the mass of the Sun and is radiating double the Sun's luminosity from its photosphere at an effective temperature of 5,860 K. Component B, the magnitude 7.90 secondary, is a smaller K-type main-sequence star with a class of K2 V. It has 0.74 times the Sun's mass and shines with 0.65 times the Sun's luminosity at an effective temperature of 4,780 K. The system as a whole may be around 7.4 billion years old with a slightly higher metallicity than the Sun. The system displays solar-like variability.
References
G-type main-sequence stars
K-type main-sequence stars
Binary stars
Hercules (constellation)
Durchmusterung objects
Gliese and GJ objects
163840
087895
6697 | HD 163840 | [
"Astronomy"
] | 536 | [
"Hercules (constellation)",
"Constellations"
] |
56,291,176 | https://en.wikipedia.org/wiki/Geobacter%20anodireducens | Geobacter anodireducens is a Gram-negative, aerotolerant, exoelectrogenic, anaerobic, non-spore-forming and non-motile bacterium from the genus of Geobacter Like others in its genus, it is commonly found in soil and uses iron as its electron acceptor. Due to its ability to generate current, it is an organism of note for Microbial fuel cell research. G. anodireducens was first isolated in 2014, and characterized in 2019, both by Dan Sun.
Characteristics
G. anodireducens is curved bacillus, most easily distinguished from its cousins Geobacter metallireducens and Geobacter sulfurreducens by its osmotolerance: it is able to withstand nearly twice the salt concentration in solution.
Genome
The genome of G. anodireducens is 3,555,507 base pairs long. The bacteria also contains a plasmid at 110,507 base pairs long. Both are circular. A total of 3,564 genes have been located on the plasmid and genome combined.
References
Bacteria described in 2014
Thermodesulfobacteriota | Geobacter anodireducens | [
"Biology"
] | 250 | [
"Bacteria stubs",
"Bacteria"
] |
56,291,446 | https://en.wikipedia.org/wiki/Geobacter%20argillaceus | Geobacter argillaceus is a non-spore-forming and motile bacterium from the genus Geobacter which has been isolated from kaolin clay.
References
Bacteria described in 2007
Thermodesulfobacteriota | Geobacter argillaceus | [
"Biology"
] | 49 | [
"Bacteria stubs",
"Bacteria"
] |
56,292,355 | https://en.wikipedia.org/wiki/Geobacter%20chapellei | Geobacter chapellei is a Gram-negative, strictly anaerobic, mesophilic and non-motile bacterium from the genus of Geobacter which has been isolated fromaq uifer sediments from the Atlantic Coastal Plain in the United States.
See also
List of bacterial orders
List of bacteria genera
References
Bacteria described in 2001
Thermodesulfobacteriota | Geobacter chapellei | [
"Biology"
] | 77 | [
"Bacteria stubs",
"Bacteria"
] |
56,292,493 | https://en.wikipedia.org/wiki/Geobacter%20daltonii | Geobacter daltonii is a Gram-negative, Fe(III)- and Uranium(IV)-reducing and non-spore-forming bacterium from the genus of Geobacter. It was isolated from sediments from the Oak Ridge Field Research Center in Oak Ridge, Tennessee in the United States. The specific epithet "daltonii" was refers to Dava Dalton, who performed the initial isolation of the strain, but died shortly thereafter.
Characteristics
Geobacter species are known for their ability to facilitate extracellular electron transfer. A feature of G. daltonii specifically is the pili structures that are electrically conductive allowing for connections to other cells, free minerals in their environment, and other electrodes. This may have implications for the utilization of G. daltonii as a tool in environmental remediation of U(VI). In 2022 a proposal was made to reclassify organisms in the Deltaproteobacteria class, including G. daltonii.
See also
List of bacterial orders
List of bacteria genera
References
Bacteria described in 2010
Thermodesulfobacteriota | Geobacter daltonii | [
"Biology"
] | 221 | [
"Bacteria stubs",
"Bacteria"
] |
56,292,836 | https://en.wikipedia.org/wiki/Geobacter%20toluenoxydans | Geobacter toluenoxydans is a bacterium from the genus of Geobacter which has been isolated from sludge from an aquifer in Stuttgart in Germany.
See also
List of bacterial orders
List of bacteria genera
References
Bacteria described in 2010
Thermodesulfobacteriota | Geobacter toluenoxydans | [
"Biology"
] | 61 | [
"Bacteria stubs",
"Bacteria"
] |
56,292,903 | https://en.wikipedia.org/wiki/Geobacter%20thiogenes | Geobacter thiogenes is a bacterium from the genus Geobacter.
References
Bacteria described in 2001
Thermodesulfobacteriota | Geobacter thiogenes | [
"Biology"
] | 32 | [
"Bacteria stubs",
"Bacteria"
] |
56,293,182 | https://en.wikipedia.org/wiki/Self-decoration%20camouflage | Self-decoration camouflage is a method of camouflage in which animals or soldiers select materials, sometimes living, from the environment and attach these to themselves for concealment.
The method was described in 1889 by William Bateson, who observed Stenorhynchus decorator crabs. It was classified as "adventitious protection" by Edward Bagnall Poulton in 1890, and as "adventitious concealing coloration" or "adventitious resemblance" by Hugh Bamford Cott in 1940, who compared it to the way Australian aborigines stalked waterfowl, covering their faces with water lily leaves.
Among animals, self-decoration is found in decorator crabs, some insects such as caddis flies and the masked hunter bug, and occasionally also in octopuses. In military camouflage, it is seen in the use of ghillie suits by snipers and the helmet nets of soldiers more generally, when these are camouflaged by inserting grass and other local plant materials, and in a more general way by the use of decorated camouflage netting over vehicles, gun emplacements and observation posts.
History
In 1889, William Bateson observed in detail the way that decorator crabs fix materials on their backs. He noted that "[t]he whole proceeding is most human and purposeful", and that if a Stenorhynchus crab is cleaned, it will "immediately begin to clothe itself again with the same care and precision as before".
In his book The Colours of Animals (1890), Edward Bagnall Poulton classified protective animal coloration into types such as warning colours and protective mimicry. He included self decoration under the heading "Adventitious Protection", quoting Bateson's account of decorator crabs.
In his textbook Adaptive Coloration in Animals (1940), Hugh Bamford Cott describes self-decoration under the heading "adventitious concealing coloration", also naming it "adventitious resemblance". He describes it as a device "perhaps unrivalled" for effective concealment, and points out that it is brought about and depends on "highly specialized behaviour". Further, it grades into other means of protection including "the borrowing of protection from aposematic partners" and the use of "fortified hiding-places" and burrows. Cott compares the way Australian aborigines once used water lily leaves over their faces to swim towards waterfowl until they were close enough to catch them by the legs.
In animals
A variety of animals, both predators and prey, make use of self-decoration to conceal themselves.
Antipredator adaptations
Decorator crabs of many species camouflage themselves with pieces of seaweed, shells, small stones, and living organisms such as hydrozoa, sponges, and sea anemones to evade predators. They pick up these pieces and stick them to their shells as semi-permanent camouflage, keeping them until they next moult. Their shells are covered with curved hairs to hold the decorations. The relationship with some of these animals, such as sea anemones is mutualistic; in the case of aposematic animals like stinging sea anemones, the crabs are making use of the warning coloration of these partners to ward off predators.
Self-decoration is seen in some insects such as caddis fly larvae, the nymphs of the masked hunter bug, and occasionally also in octopuses.
Aggressive mimicry
Chrysopidae lacewing larvae decorate themselves with a mixture of materials including moulted cuticle and their own droppings, which appears to serve both to camouflage the larvae and to repel predators. Larvae of species that eat aphids decorate themselves with the waxy material produced by the aphids; larvae decorated like this are ignored by ants which farm the aphids, whereas the ants eject undecorated larvae, making this a wolf in sheep's clothing strategy of aggressive mimicry. Some owlfly larvae, which are ambush predators, similarly self-decorate, hiding until prey comes within range.
The strategy has been used by traditional human hunters, such as when Australian aborigines dressed in emu skins and adopted emu-like postures to hunt these birds.
In military usage
Snipers, working alone, rely heavily on effective camouflage. This is often provided by a ghillie suit, a whole-body covering fitted with many loops into which the wearer can insert grass or other plant materials to match the local environment, or are made with cloth simulating tufts of leaves. Such good camouflage comes at the price of the weight of the ghillie suit and the attached materials; the suit is hot and uncomfortable to wear in hot weather, and it restricts mobility.
The ghillie suit was developed by Scottish gamekeepers for hunting deer, and adapted initially by a Scottish Highland regiment, the Lovat Scouts, for military use. In 1916, the Lovat Scouts became the British Army's first sniper unit. Snipers of many armies have since then adopted the ghillie suit for the effective concealment that it affords.
Cott used the example of the larva of the blotched emerald moth, which fixes a screen of fragments of leaves to its specially hooked bristles, to argue that military camouflage had used the same method, pointing out that the "device is ... essentially the same as one widely practised during the Great War for the concealment, not of caterpillars, but of caterpillar-tractors, [gun] battery positions, observation posts and so forth."
References
Camouflage mechanisms
Antipredator adaptations | Self-decoration camouflage | [
"Biology"
] | 1,135 | [
"Antipredator adaptations",
"Biological defense mechanisms"
] |
56,294,750 | https://en.wikipedia.org/wiki/Synthetic%20measure | A synthetic measure (or synthetic indicator) is a value that is the result of combining other metrics, which are measurements of various features.
Examples
Quality of service
There is a method to measure quality of service in hotels. In related study authors aggregate tourist opinions, measured on a scale from 1 to 10. Synthetic measure (indicator) of service quality in each hotel is calculated with the help of the aggregation operator.
Project performance
Other study proposed to use classical parameters EV, PV and AC to carry out the synthetic measure of project performance.
Rankings of countries
Different normalized stimulants and destimulants were used in research to create synthetic measure that selects countries with the best and the worst levels of implementation of Europe 2020 targets.
References
External links
Scientific works about synthetic measure on Google Scholar
Computational statistics | Synthetic measure | [
"Mathematics"
] | 162 | [
"Computational statistics",
"Computational mathematics"
] |
56,295,168 | https://en.wikipedia.org/wiki/Urethrovaginal%20fistula | A urethrovaginal fistula is an abnormal passageway that may occur the urethra and the vagina. It is a sub-set of vaginal fistulas. It results in urinary incontinence as urine continually leaves the vagina. It can occur as an obstetrical complication, catheter insertion injury or a surgical injury.
It is also called a urethral fistula and may be referred to as UVF. They are quite rare. In the developed world, they are typically due to injuries due to medical activity.
References
Noninflammatory disorders of female genital tract
Fistulas
Vaginal diseases
Human female reproductive system
Anatomy
Gynaecology | Urethrovaginal fistula | [
"Biology"
] | 147 | [
"Anatomy"
] |
56,296,165 | https://en.wikipedia.org/wiki/2018%20Hawaii%20false%20missile%20alert | On the morning of January 13, 2018, an alert was accidentally issued via the Emergency Alert System and Wireless Emergency Alert System over television, radio, and cellular networks in the U.S. state of Hawaii, instructing citizens to seek shelter due to an incoming ballistic missile. The message was sent at 8:08 a.m. local time and the state had not authorized civil defense outdoor warning sirens to sound.
38 minutes and 13 seconds later, state officials blamed a miscommunication during a drill at the Hawaii Emergency Management Agency for the first message. Then-Governor David Ige apologized for the erroneous alert. The Federal Communications Commission and the Hawaii House of Representatives launched investigations into the incident, leading to the resignation of the state's emergency management administrator.
Background
Escalating tensions between North Korea and the United States, including threats by both countries that they could use nuclear weapons against one another, prompted a heightened state of readiness in Hawaii. North Korea had conducted several intercontinental ballistic missile tests over the past year, most recently in November 2017, enhancing its strike capabilities. It is possible that North Korea may have the capability to deliver nuclear missiles to Hawaii. Hawaii is located roughly from North Korea, and a missile launched from North Korea would leave approximately 12 to 15 minutes of warning time.
Hawaii officials had been working for some time to refresh the state's emergency plans in case of a nuclear attack from North Korea. An October 2017 email from the University of Hawaii to students with the subject line "In the event of a nuclear attack", containing instructions from the Hawaii Emergency Management Agency on how to react in case of a nuclear attack, caused controversy; a university spokesman ultimately apologized for "any needless concern it may have caused". Testing of the civil defense warning sirens and attack drills were also conducted in the state on the first business day of the month beginning in December 2017. On December 1, 2017, a nuclear threat siren was tested in Hawaii for the first time in more than 30 years, the first of what state officials said would be monthly drills. At 11:45 a.m. on January 2, 2018, the state conducted its monthly test of the civil defense outdoor warning siren system including the sounding of a one-minute Attention Alert Signal (Steady Tone) followed by a one-minute Attack Warning Signal (Wailing Tone). There was no exercise or drill accompanying the test. Prior to January 13, 2018, 26 drills had been conducted. Vern Miyagi, the administrator of the Hawaii Emergency Management Agency, explained that state leaders "couldn't ignore these constant threats and missile tests from North Korea" and felt the need to prepare residents for the possibility of an attack. Officials also outlined what would happen if an emergency alert were sent: a push alert to smartphones and a message interrupting television and radio broadcasts.
Earlier in January 2018, U.S. Federal Communications Commission chairman Ajit Pai said the commission planned to vote to overhaul the wireless emergency alert system. The proposed reforms include providing more detailed information in alerts and confining emergency notifications to a more specific geographic area. Pai said he hoped the reforms, which would take effect if approved by the FCC, would lead to greater use of the alert system in local emergency situations and prompt people to take alerts they receive more seriously.
Incident
The alert
The alert was sent at 8:08 a.m. Hawaii–Aleutian Standard Time. People in Hawaii reported seeing the alert on their smartphones. Many screenshots of the push alert were shared on social media platforms, such as Twitter. The alert read, in all capital letters:
BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL.
Local television broadcasts, including a college basketball game between Florida and Ole Miss being shown on CBS affiliate KGMB and a Premier League match between Tottenham Hotspur and Everton on NBC affiliate KHNL, were also interrupted by a similar alert message, broadcast as a Civil Danger Warning. The alert message on television broadcasts took the form of both an audio message and a scrolling banner. It stated in part:
The U.S. Pacific Command has detected a missile threat to Hawaii. A missile may impact on land or sea within minutes. THIS IS NOT A DRILL. If you are indoors, stay indoors. If you are outdoors, seek immediate shelter in a building. Remain indoors well away from windows. If you are driving, pull safely to the side of the road and seek shelter in a building or lay on the floor. We will announce when the threat has ended. THIS IS NOT A DRILL. Take immediate action measures.
An alert message also interrupted radio broadcasts in the state. In Lihue, a resident reported hearing a message on the radio advising of "an incoming missile warning for the islands of Kauai and Hawaii".
Culpability for the false alert was attributed to an employee at the Hawaii Emergency Management Agency, who officials said was a 10-year agency veteran who had previously exhibited behavior that had troubled coworkers, according to The Washington Post. Vern Miyagi, then-administrator of HI-EMA, said the alert had been inadvertently triggered by the employee as he was working at the Diamond Head Crater headquarters during a shift change. During the shift change, a supervisor ran an unscheduled drill in which he contacted emergency management workers in the guise of an officer from U.S. Pacific Command, according to state officials. The supervisor deviated from the script, officials said, erroneously stating at one point, "This is not a drill", although he reportedly did state before and after the message, "Exercise, exercise, exercise", agency code to indicate a test rather than an actual emergency.
Officials said that upon hearing the supervisor's statement, the employee, who had "confused real-life events and drills" at least twice before believed there was an actual emergency, and he later attested to this in a written statement. In an interview with NBC News, the employee shared that he was "100 percent sure that it was the right decision and that it was real". The man went on to state that he is not to blame for the incident, that overall it was a system failure, and that he did exactly what he was trained to do. He clicked the button to send out an actual notification on Hawaii's emergency alert interface during what was intended to be a test of the state's ballistic missile preparations computer program and then clicked through a second screen, which had been intended as a safeguard, to confirm. An agency spokesman told The Washington Post that the employee was prompted to choose between the options "test missile alert" and "missile alert" and had selected the latter, initiating the alert sent out across the state. The employee later claimed to the Associated Press that he had not heard the "exercise" part of the phone call because a co-worker had placed it on speakerphone partway into the message, and as a result, he had been "100 percent sure" the attack was real. State officials said five other workers were present at the agency at the time and all of them recognized the phone call as an impromptu drill. Since this incident, the employee responsible has received numerous death threats and has expressed his apologies on multiple occasions.
State response
By 8:10 a.m. HST, three minutes after the first alert, Hawaii National Guard Adjutant General Arthur "Joe" Logan had contacted U.S. Pacific Command and confirmed there had been no missile launch. At that time, the Honolulu Police Department was notified that the alert had been a false alarm. Officials used the State Warning Point system at 8:13 a.m. to cancel the alert, preventing it from being sent out to any phones that had not already received it, such as those that were switched off or did not have reception. The employee who originally sent out the erroneous notification did not respond when directed to cancel the alert, according to state officials. He later said he felt like he had been dealt a "body blow" upon realizing the supposed attack had been a drill, the Associated Press reported. Another unidentified worker grabbed the employee's computer mouse and canceled the alert when the first employee failed to respond.
Official messages refuting the emergency alert were not sent out until 8:20 a.m., according to the timeline released by officials after the incident. Hawaii Emergency Management Agency accounts on Facebook and Twitter posted messages at that time urging people to disregard the erroneous alert. Minutes later, Governor David Ige retweeted the HI-EMA message on Twitter and posted a similar message on Facebook to notify followers that the alert had been canceled. Ige later said the delay was caused in part by the fact he did not know his Twitter login information. An email from the state was also sent at about 8:25 a.m. advising that the initial alert was not correct, the Honolulu Star-Advertiser reported.
Electronic highway signs were also used to spread the word that the alert had been issued "in error" and that there was no threat to Hawaii.
Second alert
At 8:45 a.m. HST, 38 minutes after the initial alert was sent to smartphones in Hawaii, a second emergency alert was sent, which stated:
There is no missile threat or danger to the State of Hawaii. Repeat. False Alarm.
The second alert was sent "well after everyone from Hawaii's congressional delegation to the U.S. Pacific Command had assured the world on Twitter that it was a false alarm", Pacific Business News remarked.
Governor David Ige explained at a news conference that afternoon that officials "had to initiate a manual process" and obtain authorization from the Federal Emergency Management Agency in order to send the second alert because there was no automated way to countermand the first alert. Those procedures accounted for the delay more than 30 minutes after officials had confirmed internally that the alert was inaccurate, according to officials.
Effects
During the 38 minutes between the first and second alerts, Hawaii's siren warning system—which had been tested as part of a missile preparedness exercise the previous month for the first time since the Cold War—was not formally activated. Had a missile actually been launched, the Hawaii push alert should have been followed up with another set of alarms with sirens, which did not happen, as observed by some residents. Nevertheless, officials stated that some sirens did appear to go off in some communities, with some residents reporting sirens activated on Oahu a few minutes after the push notification. Little to no activity was reported at military bases in the state. Some commercial flights were reportedly delayed for a short time, although the Hawaii Department of Transportation said there were no widespread impacts at the state's airports and harbors.
Disruptions were reported across the state. Honolulu Civil Beat reported that motorists parked inside the Interstate H-3 tunnel on the island of Oahu for shelter. Hawaii News Now reported that alarms sounded at Aloha Gymfest, an international gymnastics meet in Kailua, sending hundreds of people running for cover. Students at the University of Hawaii at Manoa reportedly headed for marked fallout shelters on campus but, finding them locked, ended up taking shelter in nearby classrooms instead. Officials at the Sony Open PGA Tour golf tournament on Oahu ordered an evacuation of the media center, while staff members sought cover in the kitchen and players' locker room. Tourists at Kualoa Ranch in Kaneohe were taken by staff up to Battery Cooper Bunker, a concrete bunker built in the mountains during WW2 as part of former Kualoa Airfield, and told to shelter there. Congresswoman Colleen Hanabusa later said her husband had been driving on a Honolulu-area freeway and saw cars speeding at up to after the alert was sent out. Many Hawaii residents and visitors sought shelter or rushed through emergency preparations where they were. Some discounted the alarm when they realized that they heard no sirens, and that they personally saw no immediate coverage on television or local radio. Others were in areas where sirens did go off; in addition, some television stations did broadcast the alert.
The incident also created a strain on Hawaii's telephone system. Civil Defense offices in Hawaii were inundated with calls from frightened citizens asking for advice or more information, the New Zealand Herald reported. Many calls to 911 would not go through. Many wireless data services were likewise initially jammed, leaving many unable to access the Internet to confirm whether the alarm was real. Some residents called friends or family members to say goodbye. Others remained where they were, as with Mark Gardner, who, believing that escape was impossible, recorded a final message to his family in anticipation of the missile striking its target.
U.S. Defense Secretary James Mattis reported that the false alert did not appear to have prompted any sort of reaction from the North Korean government.
One man suffered a heart attack minutes after saying what he thought were his last goodbyes to his children following the initial alert, though he survived the heart attack.
The event was examined in an academic article by Richard Ling and Brett Oppegaard. The analysis interviewed 418 people and showed how information (and false information) can propagate quickly in society.
Responses
Fear and panic quickly spread through the locals and tourists of Hawaii. Many Twitter posts and screenshots of text messages shared on social media in the immediate wake of the first alert conveyed confusion, alarm, and fear among those who received the warning. With very little warning and instructions, many people were unsure of what to do. This later became a major criticism of the Hawaii Emergency Management Agency and is a key issue they are working on to improve, which will ensure that people can receive more accurate information in the case of a real emergency.
Federal officials
Members of Hawaii's congressional delegation also took to Twitter to dispel the false alarm. Congresswoman Tulsi Gabbard tweeted at 8:19 a.m. HST, about 12 minutes after the initial alert was sent, stating in all capitals that the message was a "false alarm" and that she had confirmed with officials that there was no incoming ballistic missile toward Hawaii. The next day, she told CNN that the incident highlighted the need for President Donald Trump to negotiate with North Korean leader Kim Jong-un to resolve nuclear tensions between the United States and North Korea, and she called for those responsible for the erroneous alert in Hawaii "to be held accountable". Congresswoman Colleen Hanabusa, a 2018 candidate for governor, tweeted that the "panic and fear created by this false alarm was very dangerous". In further comments, Hanabusa panned the delay between the two emergency alerts, suggesting it should not have taken 38 minutes for the second message to be sent. Senator Mazie Hirono tweeted that officials "need to get to the bottom of what happened and make sure it never happens again". In his own tweets immediately after the incident, Senator Brian Schatz repeated that the first alert had been a false alarm. He described the erroneous alert message as "totally inexcusable", adding: "The whole state was terrified. There needs to be tough and quick accountability and a fixed process."
Commander David Benham, a spokesman for U.S. Pacific Command, confirmed to media that there was no imminent missile threat to Hawaii. A spokesman for North American Aerospace Defense Command (NORAD) stated that "NORAD did not see anything that indicated any sort of threat to Hawaii" and said NORAD and U.S. Northern Command were still verifying what had happened. President Trump had also been under fire by critics for his "lack of response" some said. A White House official said the alert had been part of "a state exercise" and President Trump was briefed on the situation. Trump ordered National Security Advisor H.R. McMaster to take charge of the administration's response to the incident. About the incident, Trump said, "They made a mistake."
U.S. Homeland Security Secretary Kirstjen Nielsen said the incident was "unfortunate" and officials were working to prevent a similar false alert from being issued in the future. Speaking on Fox News the next day, she said people "can trust government systems" and should pay attention to any alerts they receive from authorities in the future, in spite of the January 13 incident in Hawaii.
Ajit Pai, chairman of the U.S. Federal Communications Commission, announced the commission would launch a full investigation into the false alert. He blamed Hawaii's government for not having "reasonable safeguards or process controls in place to prevent the transmission of a false alert", later stating that other agencies should "learn from these mistakes".
Congresswoman Tulsi Gabbard stated in an interview after the second emergency alert was sent that the incident was "a taste of the stark reality of what we face here of a potential nuclear strike on Hawaii", referring to the possibility of a North Korean attack. She and former Secretary of Defense William J. Perry both said the false alert highlighted the possibility of an "accidental nuclear war", in which a technical or human error leads to the use of nuclear weapons due to a misunderstanding or misinterpretation.
State officials
Honolulu Mayor Kirk Caldwell also tweeted that the message had been a false alarm, saying the message had been sent in error before the second alert was sent out by the Hawaii Emergency Management Agency.
HI-EMA administrator Vern Miyagi took responsibility for the incident, ultimately resigning over it. Miyagi described the initial warning as a "mistake", saying it "should have been caught" before the alert was sent out. HI-EMA officials, including Miyagi, said there was no evidence that the agency's systems had been hacked to send the false emergency message.
Miyagi apologized for the false alert, as did Governor David Ige, who called the incident "unfortunate and regrettable". They said officials would review the state's procedures to prevent it from happening again. Ige said:
I know first-hand how today's false alarm affected all of us here in Hawaii, and I am sorry for the pain and confusion it caused. I, too, am extremely upset about this and am doing everything I can do to immediately improve our emergency management systems, procedures and staffing.
Hawaii Senate Majority Leader J. Kalani English said he was "outraged" by the error, which caused unnecessary "panic and pandemonium" throughout the state. Hawaii House of Representatives Speaker Scott K. Saiki announced the House would investigate the incident:
This system we have been told to rely upon failed and failed miserably today. I am deeply troubled by this misstep that could have had dire consequences. Measures must be taken to avoid further incidents that caused wholesale alarm and chaos today. Clearly, government agencies are not prepared and lack the capacity to deal with emergency situations. Apparently, the wrong button was pushed and it took over 30 minutes for a correction to be announced. Parents and children panicked during those 30 minutes. The Hawaii House of Representatives will immediately investigate what happened and there be consequences. This cannot happen again.
The deputy adjutant of the Hawaii National Guard said that notwithstanding the erroneous alert, people should continue to follow instructions and take shelter if another alert is sent in the future.
Aftermath
Investigations
State officials held a news conference in the afternoon of January 13 to address the incident. State officials placed former Hawaii Army National Guard commander Bruce E. Oliveira in charge of internally investigating the events that resulted in the false alert being sent out. In his report, published January 30, Oliveira faulted "insufficient management controls, poor computer software design, and human factors" for the incident.
Officials did not name the employee responsible for the error. Hawaii Emergency Management Agency head Vern Miyagi initially declined to say whether the employee, who he said felt "terrible" about the false alert, would face discipline. An agency spokesman said January 14 the employee had been "temporarily reassigned" to a position that did not allow him access to the emergency warning system, pending the result of the internal investigation. The employee was ultimately fired on January 26, following findings in Oliveira's investigation regarding his work history, with NBC News reporting that the employee had "a history of confusing drill and real-world events". A second employee, who was also not identified and whose role in the incident was not disclosed, was suspended without pay. Toby Clairmont, HI-EMA's executive officer, announced January 20 he planned to retire by the end of the year.
The Federal Communications Commission also announced that it would conduct a full investigation into the incident. On January 25, an FCC official announced that the former employee responsible for sending the false report was refusing to cooperate with the FCC probe of the incident. The FCC report, released January 30, faulted the state for failing to quickly notify the public and not having safeguards in place sufficient to prevent the error. FCC Chairman Ajit Pai stated:
Every state and local government that originates alerts needs to learn from these mistakes. Each should make sure they have adequate safeguards in place.… The public needs to be able to trust that when the government issues an alert it is indeed a credible alert.
Miyagi resigned as HI-EMA administrator the same day the state and federal reports were released. Clairmont announced his resignation a day later.
Other official actions
Then-administrator Vern Miyagi said the Hawaii Emergency Management Agency suspended tests while assessing what had happened following the incident. He also announced the agency immediately changed its procedures to require two people, instead of just one, to send out both test alerts and actual alerts. HI-EMA employees will be "counseled and drilled so this never happens again", Miyagi said January 14.
Governor David Ige announced January 15 that he was appointing Brigadier General Kenneth Hara, Hawaii's deputy adjutant general, to oversee a review of the state's emergency management systems and procedures and implement reforms. The agency also moved quickly to implement a cancellation command that officials said can be triggered within seconds of an erroneous alert being sent out, which it reportedly lacked before the January 13 incident. The Hawaii emergency alert interface screen was updated with a BMD False Alarm selection the same day, addressing a system deficiency that made it difficult for the state to countermand an alert sent in error.
HI-EMA reported that some of its employees received death threats after the false alert incident. In a rare public address, Ige called the threats "completely unacceptable" and said he was "ultimately responsible" for the error.
Although Governor Ige's office issued on February 27, 2018, a Siren and Emergency Alert System Test for March 1, 2018, the state of Hawaii did not test the nuclear warning siren in March and dropped its monthly test of the nuclear warning siren beginning on March 1, 2018.
In July 2018, the FCC issued a report and order which makes changes to EAS regulations to "improve the integrity, efficacy, and reliability" of the system and "minimize the potential for false alerts". The changes require EAS participants to configure their hardware to "reject Common Alerting Protocol-based alerts that contain an invalid digital signature and legacy (over-the-air)-based alerts whose expiration time falls outside of specific time limits", and report any false alarms to the FCC. The commission also implemented procedures for authorizing voluntary participation in "live code" tests—public exercises that simulate an actual emergency in order to "promote greater proficiency" in the system by EAS operators and participants. These changes were the result of recommendations from the FCC's report on the Hawaii incident.
Outside Hawaii
North Korea's Rodong Sinmun, the Workers' Party of Korea newspaper, described the false alarm as a "tragicomedy".
An official with the Division of Homeland Security & Emergency Management in the U.S. state of Alaska, also within the theoretical range of North Korean nuclear missiles, said his department encourages Alaskans to shelter in place rather than trying to get elsewhere if there is an attack, as many people in Hawaii did after the false alert was issued.
U.S. Senator Brian Schatz, one of Hawaii's two members of the United States Senate, introduced federal legislation that would prohibit state and local agencies from notifying the public of a missile launch, placing the responsibility on federal authorities to make that determination. In July 2018, Schatz also introduced the Reliable Emergency Alert Distribution Improvement (READI) Act, which proposed that a reporting system be established for false alarms, that FEMA establish best practices on use of emergency alerts and preventing dissemination of false alarms, and that State Emergency Communications Committees (SECCs) be required to update their procedures on a periodic basis. The act also proposed user-visible changes to EAS behavior, including requiring that users be prevented from opting out of wireless alerts originating from FEMA, mandating repetition of EAS broadcasts for active FEMA or presidential alerts, and compelling the FCC to investigate the feasibility of delivering emergency alerts via over-the-top streaming media services. The bill passed in the Senate but failed in the House of Representatives.
Similar incidents
On January 16, only a few days after Hawaii's false alarm, Japan had a similar alarm sent out. An NHK news staffer sent an erroneous alert about a North Korean missile fired at Japan to 300,000 followers of its "NHK News and Disaster Prevention" service. Previously, NHK and other Japanese media sent alerts for each North Korean missile test, but this alert stated "It appears that North Korea has launched a missile". Overall, the public reaction was not as extreme as what was witnessed in Hawaii as the NHK within 5 minutes of the alert posted on their website stating that it was a false alarm.
On September 18, 2019, emergency sirens were accidentally set off on the island of Oahu during police training, causing confusion and fear among residents. Again, HI-EMA was required to issue a retraction on Twitter.
On January 12, 2020, nearly two years to the date of the Hawaii false alarm, the emergency operations center for the Canadian province of Ontario mistakenly issued an emergency alert on its Alert Ready system for all television stations and television providers, radio stations, and wireless networks in the province, containing an advisory relating to an alleged incident being addressed at the Pickering Nuclear Generating Station. The alert was confirmed to be a false alarm. In a nearly-identical manner to the Hawaii incident, the false alarm was the result of an operator error by a provincial emergency operations officer during a routine internal test at the beginning of a shift; the officer accidentally forgot to log out of the live Alert Ready system (done to check if the system is operational) before running the test (meant to be sent on a second, internal system), while there was also a breakdown in communications with supervisors over the issuance of a second alert to retract it.
In popular culture
The events of the Hawaii false missile incident served as the basis for writer Dan Scott's radio play Emergency Alert: Ballistic Missile Inbound which was broadcast on BBC Radio 4 on 20th March 2024. The play took key events from the incident and transported them from Hawaii to an English village in 2024.
Jim Carrey revealed he was present on the island during the alert, and felt that he and his family were going to die, on the Tonight Show with Jimmy Fallon in 2020.
See also
List of nuclear close calls
Notes
References
2018 controversies in the United States
2018 in American politics
False missile alert
Disaster preparedness in the United States
2018
January 2018 events in Oceania
January 2018 events in the United States
Nuclear safety and security
Nuclear warfare
United States civil defense
United States nuclear command and control
User errors | 2018 Hawaii false missile alert | [
"Chemistry"
] | 5,668 | [
"Radioactivity",
"Nuclear warfare"
] |
56,296,196 | https://en.wikipedia.org/wiki/Copper%28I%29%20tert-butoxide | Copper(I) tert-butoxide is an alkoxide of copper(I). It is a white sublimable solid. It is a reagent in the synthesis of other copper compounds.
The compound was originally obtained by salt metathesis from lithium tert-butoxide and copper(I) chloride. An octameric form was obtained by alcoholysis of mesitylcopper:
8 CuC6H2Me3 + 8 HOBu-t → 8 HC6H2Me3 + [CuOBu-t]8
References
Copper(I) compounds
Tert-butyl compounds
Alkoxides | Copper(I) tert-butoxide | [
"Chemistry"
] | 131 | [
"Bases (chemistry)",
"Alkoxides",
"Functional groups"
] |
56,296,491 | https://en.wikipedia.org/wiki/Silkhenge | Silkhenge structures are a means of spider reproduction used by one or more currently-unknown species of spider. It typically consists of a central "spire" constructed of spider silk, containing one to two eggs, surrounded by a sort of fence of silk in a circle.
Discovery
In August 2013, Georgia Tech student Troy Alexander was visiting Tambopata National Reserve in Peru. He found, under a tarpaulin, a tiny bit of silk in a circular pattern approximately one inch in diameter. Upon further investigation of the area, Alexander found three additional similar structures. He posted a picture on Reddit asking for help identifying it. No information was forthcoming, as this turned out to be a completely unknown phenomenon. His discovery acquired the name "silkhenge" because of its similarity to Stonehenge.
At the end of that year, an eight-day expedition led by Phil Torres found dozens more examples of this phenomenon, generally on the trunks of bamboo and cecropia trees. Spiderlings hatching from the structures were documented, but like many baby arthropods they lacked the features typically used to identify adults, and none lived to adulthood. DNA tests were also inconclusive, so the species creating these structures remained unidentified. A video was posted on YouTube of spiderlings hatching.
One hypothesized purpose of the fence is that it serves to trap mites and other small arthropods known to share the same habitat. This could, in turn, secure a food source that would be easily accessible to the spiderlings upon hatching. It has also been proposed that it protects the eggs and spiderlings from possible predators such as ants.
References
Spiders
Silk
Invertebrates of Peru
Shelters built or used by animals
Eggs
2013 in biology | Silkhenge | [
"Biology"
] | 354 | [
"Ethology stubs",
"Ethology",
"Behavior",
"Shelters built or used by animals"
] |
56,296,730 | https://en.wikipedia.org/wiki/A%2BBE | Architecture and the Built Environment (A+BE) is an open access series that publishes PhD theses of students of the Delft University of Technology's Graduate School of Architecture and the Built Environment, covering subjects such as: architecture, architectural engineering, green building, heritage, history, urbanism, real estate, housing, geomatics, geodesign, and management. The series was started in 2011 as part of the university's policy on open access and start of the Graduate School of Architecture and the Built Environment. The series is abstracted and indexed in Scopus.
References
External links
Architecture journals
Publications established in 2011
English-language journals
Quarterly journals
Creative Commons-licensed journals | A+BE | [
"Engineering"
] | 139 | [
"Architecture stubs",
"Architecture"
] |
56,297,178 | https://en.wikipedia.org/wiki/Bacterioplankton%20counting%20methods | Bacterioplankton counting is the estimation of the abundance of bacterioplankton in a specific body of water, which is useful information to marine microbiologists. Various counting methodologies have been developed over the years to determine the number present in the water being observed. Methods used for counting bacterioplankton include epifluorescence microscopy, flow cytometry, measures of productivity through frequency of dividing cells (FDC), thymidine incorporation, and leucine incorporation.
Factors such as salinity, temperature, latitude, various nutrient levels, water movement and the presence of other organisms can affect bacterioplankton enumeration. Changes in these factors affect the bacterioplankton count, causing it to vary by body of water, location, distance from shore and season.
Bacterioplankton count is usually expressed in cells per ml (cells ml−1).
Uses
In understanding marine microbiology and the aquatic ecosystem, bacterioplankton counts can be useful. Observation of bacterioplankton number can provide more information in the following:
Processes involved in various nutrient cycling in the aquatic systems
For aquatic productivity
For determining environmental changes, especially extremes
Variation in bacterioplankton count not derived by seasonal adjustments can provide correlation with environmental stresses such as having a significant shift in nutrient levels within a body of water
Nutrient composition in aquatic ecosystem
Abundance and conditions of other aquatic organisms (i.e. shrimp)
Epifluorescence microscopy
Epifluorescence microscopy is an advanced optical microscope technique that relies on the use of fluorescent dyes that bind to specific biological markers, which then emit a distinctive emission spectra that is identified through the lens. Fluorescent dyes include DAPI, Acridine Orange, SYBR Green 1, and YO-PRO-1, all of which are capable of staining both DNA and RNA structures in biological samples such as bacteria and viruses. However, DNA staining is primarily used for bacterial cell identification. With modern epifluorescence microscopy, the industry standard for estimating and counting bacterial cell quantities is by the use of a DAPI stain. This technique can be performed for samples from a wide range of environments and locations, such as seawater, various sources of freshwater, as well as soils and sediments.
Enumeration technique
In a standard experiment, prepared bacterial samples are placed onto counting slides and then viewed under an epifluorescence microscope. Magnification is set to a level where the 0.1 X 0.1 mm square units on the counting slide are clearly visible. To quantify the bacteria, cells are counted in 5-30 random square unit field-of-views and an average bacteria count per field is tabulated. This value is then extrapolated to estimate the total bacterial cell-count per mL by determining the total number of fields-of-view on the slide deposition area and multiplying this by the average bacterial count per counting unit.
Reliability
To enumerate bacterial cell quantities, only small portions of bacteria in a sample are physically counted for logistical reasons, upon which total abundances are estimated by extrapolation. Mean values are then used for comparison among samples. However the accuracy of this technique, where tabulation of only a small subset is used to estimate total abundance quantities, has been brought into question. Primarily, it has been shown that the distribution of bacterial cells on counting slides can be uneven and inconsistent. In addition, to get a legitimate estimate of bacterial counts by using this technique, it has been suggested that more than 350 individual cells, from 20 fields of view must be measured. This can be not only time-consuming, but difficult to achieve in certain samples.
Flow Cytometry
Flow cytometric analysis (or, flow cytometry) is a common procedure in many clinical applications. However, despite its discovery more than three decades ago, its adoption by aquatic microbial ecology in enumeration of bacterioplankton, has been relatively slow. Its use is yet to surpass epifluorescence microscopy. Despite both abundance estimation techniques being relatively accurate, flow cytometry is less prone to human error, more precise, pertains a higher resolution and is capable of examining tens of thousands of cells in a matter of minutes. Flow cytometry is also able to provide information regarding size, activity and morphology of cells besides abundance of cells.
Flow cytometry can be used to distinguish and quantify both photosynthetic and non-photosynthetic bacterioplankton. Quantification of photosynthetic prokaryotes such as cyanobacteria and picoeukaryotic algae is made possible by the ability of photosynthetic pigments to fluoresce. For instance, the different formation of photosynthetic pigments in the two major photosynthetic prokaryotes, Prochlorococcus and Synechococcus, enable their very distinction. Prochlorococcus contains divynyl-chlorophylls a and b which display solely red fluorescence under excitation by blue or UV light, while Synechococcus emits both orange and red fluorescence; orange from phycobilins and red from chlorophyll. Besides fluorescence, Prochlorococcus and Synechococus are of significantly different sizes and hence deliver different scatter signals upon flow cytometric analysis. This further helps in their differentiation. Quantification of prochlorococcus is considered a major breakthrough as it has almost only been possible through flow cytometry. This is due to the inability of epifluorescence microscopy to detect the low chlorophyll autofluorescence present in Prochlorococcus.
Besides photosynthetic bacterioplankton, non-photosynthetic bacterioplankton can also be enumerated by flow cytometry. This is done via DNA or food vacuole staining. Flow cytometry has especially been successful at differentiating Prochloroccocus from heterotrophic bacteria, whose counts were initially confounded due to their similar size.
Use of epifluorescence microscopy over flow cytometry in many microbial ecology labs can be blamed on a number of economic and practical factors. First, the use of commercial flow cytometers requires the expertise of a rigorously trained technician. Second, flow cytometers are fairly expensive in comparison to epi-fluorescence microscopy apparatus. Third, many flow cytometers are designed to examine blood cells; oceanic bacteria are relatively small and hence approach limit of resolution in many commercial flow cytometers.
Enumeration Process
Flow cytometric quantification of bacterioplankton involves four steps: fixation, staining, data processing and data interpretation.
Fixation
Fixation is done to not only preserve sample, but also to increase permeability of cells to stains. However, most common fixation agents have the capacity to alter cells by changing certain aspects such as size, how light is scattered, autofluorescence and nucleic acids. This is problematic as flow cytometric distinction of cells relies on these qualities. Some fixatives also lead to complete loss of cells. Presently, some of the agents used in the fixation process include two variations of formaldehyde (formalin and paraformaldehyde), 70% ethanol, glutaraldehyde and TCA. It is presumed that the best fixation agent for protein and nucleic acids is paraformaldehyde due to its ability to swiftly enter cells.
Staining
In flow cytometry, staining enables distinction of bacterioplankton from non-bacterial particles. It involves the incubation of sample in the wide array of fluorochromes such as UV-excited dyes (DAPI and Hoechst 33342) and blue-light-excited nucleic acid dyes (TO-PRO-1,TOTO-1, SYBR Green I). For a long time, flow cytometers utilized UV-excited dyes to examine bacterioplankton which could be used in either low-cost flow cytometers with limited sensitivity, or expensive flow cytometers with the high sensitivity needed to distinguish heterotrophic bacteria from autotrophs. The introduction of blue-excited dyes such as SYBR Green I, enabled high quality flow cytometric analysis of bacterioplankton on low-cost, high-sensitivity flow cytometers.
Incubation times for optimum staining varies from compound to compound. UV-excited dyes can require an hour or more while blue-light-excited dyes require a mere 15 minutes.
Staining can be accompanied by buffers such as Triton X-100 which make cells more permeable to stains. They are especially used in cell-impermeant dyes like TO-PRO-1. Buffers are also used to dilute dyes sensitive to ionic strength such as Picogreen, YO-PRO-1 and YOYO-1. The use of buffers however, can be harmful to cells as buffers like Triton-X-100 can not only extinguish chlorophyll fluorescence, but also create unwanted background fluorescence. This can increase the difficulty of distinguishing between heterotrophic bacteria and autotrophic prokaryotes.
Counting
In a flow cytometric analysis, over 200 cells pass in front of a laser beam or mercury lamp every second, a cell at a time. Photomultipliers gather the amount of light each particle scatters and the fluorescence emitted upon excitation. This information is then internalized and interpreted by the system as an event. However, despite the ability of flow cytometers to count cells with very little effort, most have no way of determining actual concentration of cells. This can be determined through a variety of methods including, use of reference beads whose quantity is pre-determined (helps determine the ratio of bacteria to beads), weight measurements before and after experiment and daily calibration of flow.
A big advantage of flow cytometers is their ability to identify different populations of bacterioplankton. This discrimination is done via analysis of four factors; light scatter, green fluorescence, blue fluorescence and red fluorescence. Light scatter analysis is inadequate alone and is often examined alongside fluorescence for a number of reasons; first, sea water contains many particles that scatter light like bacteria. Second, the sizes of many oceanic bacteria approach limit of resolution. The amount of light scattered by cells is determined by not only size of cells, but also internal structure, refractive index, shape and orientation of particle. Scattered light is classified into either forward scatter (FSC) or side scatter (SSC). The former has been associated with cell volume and mass while the latter has been associated with index of refraction, content and granularity of cells
When cell concentrations are higher than 2.5 × 106 cells per ml, the likelihood of more than once cell passing in close proximity and being recorded as a single event is magnified. This is known as coincidence and can be easily avoided by diluting sample before hand
Measures of productivity
Frequency of dividing cells
Frequency of dividing cells (FDC) is a method used to predict the average growth rate of an aquatic heterotrophic bacterial community. The method uses cell division, specifically septum formation, as a proxy for growth rate. Cells are considered divided, when cavities between individual cells (invagination) are observed under epifluorescence microscopy. FDC is based on the assumption that there relationship between the proportion of cells currently dividing and the growth rate in a bacterial community.
Thymidine incorporation
Thymidine incorporation is one of the most extensively used methods to estimate bacterial growth. Thymidine is a precursor for DNA, and DNA synthesis can be measured by tritiated thymidine incorporation into nucleic acids. Thymidine incorporation measures growth based on rates of DNA synthesis, using the assumption that only growing cells can incorporate the radioactive thymidine to synthesize DNA.
Weaknesses of this procedure include labeling of other molecules besides DNA when tritiated thymidine is added to a sample. In cases of carbon limitation, thymidine may also be used as a carbon source instead of as a DNA precursor. Results of thymidine incorporation experiments may be misleading when the proportion of thymidine incorporated into DNA compared to other molecules is not known.
Leucine incorporation
Leucine incorporation is used as a measure of protein synthesis in aquatic bacteria communities. Radio-labeled leucine is added to samples, and its accumulation into proteins, the hot trichloroacetic acid (CA)-insoluble parts of the cell is determined. The samples are then collected on membrane filter. Leucine protein is taken up by more than 50% of aquatic bacterial populations, and leucine incorporation can be used to estimate nitrogen utilization in the bacterial community.
Marine seasonal succession dynamics
As bacterial populations have unique metabolisms and resource preferences, the use of high-resolution time-series analysis of bacterial compositions allows for the identification of patterns in seasonal bacterial succession. Differences in bacterial community compositions give rise to particular permutations of interspecies bacterial interactions with photosynthetic plankton, protist grazers, and phages thereby impacting seasonality dynamics. Statistical methods used to verify patterns in population dynamics and composition are demonstrated to be replicable over some years, and environmental factors served as predictors of these temporal patterns.
Seasonal succession in temperate regions
As seasonal successions of phytoplankton populations follow a consistent recurring pattern, bacterial dynamics and phytoplankton succession can be correlated. In general, seasonal changes in bacterial composition follow changes in temperature and chlorophyll a, while nutrient availability limits bacterioplankton growth rates. During water column mixing in late autumn/winter, nutrients brought to the surface kicks start a distinct diatom spring bloom followed by dinoflagellates. After the spring bloom, bacterial production and growth become elevated due to the release of Dissolved organic matter (DOM) from phytoplankton decay. In this early succession stage, members of the class Flavobacteria (Bacteroidetes) are typically the dominant components of the bacterial community. Genome analysis and meta-transcriptomics have uncovered the presence of bacteria containing multiple hydrolytic enzymes facilitating the degradation and assimilation of DOM. During spring blooms, some members of the Roseobacter clade (Alphaproteobacteria) and some Gammaproteobacteria are usually associated with DOM degradation. As temperatures increase and the nutrients from the spring bloom gets depleted, smaller phytoplankton and cyanobacteria grow in the now oligotrophic waters.
As waters become stratified in summer, Roseobacter, SAR86 (Gammaproteobacteria), and SAR11 (Alphaproteobacteria) clades of bacteria increase in abundance. The frequently observed autumn diatom and dinoflagellate blooms are correlated with supplementary nutrient inputs and high-frequency sampling in the Baltic Sea found that in autumn, Actinomycetota generally increase followed by different autumn-specific Flavobacteria, SAR11, and Planctomycetota.
In the Mediterranean Sea, deep winter mixing allows members of the SAR11 clade to achieve increased diversity as the oligotrophic populations that once dominated during the summer stratification die off slowly. Among archaea in the Mediterranean Sea, Nitrososphaerota (formerly Thaumarchaeota) Marine Group I (MGI) and Euryarchaeota Marine Group II (MGII.B) populations became dominant in winter. While in the Baltic Sea, winter mixing brings Campylobacterota and archaea populations to the surface from their deep habitat.
References
Biological oceanography
Laboratory techniques | Bacterioplankton counting methods | [
"Chemistry"
] | 3,341 | [
"nan"
] |
56,299,797 | https://en.wikipedia.org/wiki/List%20of%20organisms%20named%20after%20the%20Harry%20Potter%20series | Newly created taxonomic names in biological nomenclature often reflect the discoverer's interests or honour those the discoverer holds in esteem. This is a list of real organisms with scientific names chosen to reference the fictional Harry Potter series by J.K. Rowling.
Named after wizards
Named after magical creatures
Named after spells, objects, and locations
See also
List of unusual biological names
List of organisms named after works of fiction
List of organisms named after famous people
References
Harry Potter
organisms
Taxonomic lists | List of organisms named after the Harry Potter series | [
"Biology"
] | 96 | [
"Lists of biota",
"Taxonomy (biology)",
"Taxonomic lists"
] |
56,300,627 | https://en.wikipedia.org/wiki/Boletus%20aurantiosplendens | Boletus aurantiosplendens is a species of fungus native to eastern North America. Timothy J Baroni described the species in 1998, from material collected near Franklin in Macon County, North Carolina. The species name is from the Latin words aurantium "orange", and splendens "bright".
The cap is in diameter, and is convex to flattened in shape. Its colour ranges from mandarin orange to yellowish brown, with young mushroom caps having a more tan centre and orange at the cap margin. The cap surface has a velvety or suede feel. The flesh is bright or light yellow and darkens slightly on bruising. Underneath the cap, the mushroom has bright yellow pores. They are adnexed at the junction of the stalk. The pores themselves are in diameter and round or slightly angular. The spore print is olive or dark brown. The stalk is high and wide.
Its edibility is unknown.
The mushrooms appear from July to September, in humus in mixed woodlands under North American beech (Fagus grandifolia), oak (Quercus), hickory (Carya), red maple (Acer rubrum), American tulip tree (Liriodendron tulipifera) and shortleaf pine (Pinus echinata). It is only known from seven sites across 600 km, in central and western North Carolina, western South Carolina, northern Georgia and eastern Tennessee.
As it is such a striking mushroom, it is hard to overlook and is hence thought not to have many overlooked colonies. It has therefore been proposed that this species be rated as near threatened on the IUCN Red List.
References
aurantiosplendens
Fungi described in 1998
Fungi of North America
Fungus species | Boletus aurantiosplendens | [
"Biology"
] | 355 | [
"Fungi",
"Fungus species"
] |
56,300,713 | https://en.wikipedia.org/wiki/Caldanaerovirga | Caldanaerovirga is a xylanolytic, anaerobic and alkalithermophilic genus of bacteria from the family of Thermosediminibacterales with one known species (Caldanaerovirga acetigignens).
See also
List of Bacteria genera
List of bacterial orders
References
Further reading
Thermoanaerobacterales
Monotypic bacteria genera
Bacteria genera
Thermophiles
Anaerobes | Caldanaerovirga | [
"Biology"
] | 92 | [
"Bacteria",
"Anaerobes"
] |
56,300,771 | https://en.wikipedia.org/wiki/Caloribacterium | Caldanaerobius is a moderately thermophilic and anaerobic genus of bacteria from the family of Thermoanaerobacteraceae with one known species (Caloribacterium cisternae).
See also
List of Bacteria genera
List of bacterial orders
References
Thermoanaerobacterales
Monotypic bacteria genera
Bacteria genera
Thermophiles
Anaerobes | Caloribacterium | [
"Biology"
] | 81 | [
"Bacteria",
"Anaerobes"
] |
56,301,686 | https://en.wikipedia.org/wiki/HP%20Spectre | HP Spectre is a line of premium portable computers from HP Inc. (formerly Hewlett-Packard). Beginning as a high-end version of the HP Envy line in 2012, it became HP's flagship line of laptop products for consumers as of 2015.
The line is slowly being phased out since 2024 following a corporate brand streamlining that year, with all new consumer portable computers to be rebranded as OmniBook (a revival of an old Hewlett-Packard brand of the same name that was defunct after the 2002 merger with Compaq).
Models
Envy Spectre / Spectre XT
The Spectre first appeared as a model under the Envy series: Envy 14 Spectre. This ultrabook (i.e. Intel's designation of thin high-end laptops) received a large amount of attention when revealed at CES 2012, and it won CNET's Best of CES award in its category. Retailing for US$1399, it weighs four pounds and includes a radiance display, a gorilla glass screen and palm rest, a buttonless multi-touch touchpad, an NFC chip and solid-state drive.
Envy Spectre XT is a 13-inch ultrabook that retailed for US$999 in 2012. A variant called Envy Spectre XT Pro was also released which is the same but includes a Tpm module and ships with Windows 7 Professional. It retailed for $100 extra.
The Spectre XT TouchSmart (see also: HP TouchSmart) has the same design as the Envy Spectre XT, but with a larger footprint and the addition of a touch operated display. Announced in September 2012, it shipped with Windows 8.
Spectre One
In September 2012, HP announced Spectre One, an all in one desktop computer shipping with Windows 8. It has a 23.6 inch display, measures 11.5 mm thick, and covered by edge to edge glass.
Spectre 13 / x2
The HP Spectre 13 ultrabook (model no. series 13-3000) introduced in 2013 has a fourth generation Intel Core (Haswell) processor, Intel HD 4400 graphics, and a full HD IPS display with optional 2560 x 1440 Sharp IGZO display upgrade.
The Spectre 13 x2 (model no. series 13-H) is a 13.3-inch detachable hybrid ultrabook that doubles as a standalone tablet or a laptop. This is the first fanless detachable hybrid ultrabook powered by Intel's Haswell (fourth generation Core) processor. It was available for pre-order in October 2013 with prices of $1099.
Spectre x360
The Spectre x360 models are 2-in-1 convertibles; its name refers to its 360 degree hinge. HP also make similar x360 branded convertibles in the Envy and Pavilion lines.
The first Spectre x360 (also called Spectre Pro x360) ran on Broadwell 5th generation Intel Core. Released in March 2015, retailing for US$899. It has a distinctive HEWLETT PACKARD wordmark embossed on the front and the lid. In October 2015, an updated x360 (also called Spectre Pro x360 G2) came out with the 6th generation Skylake processor. At CES 2016 the 15-inch model with Skylake was announced.
In October 2016, a third generation Spectre x360 13 was released with Intel's Kaby Lake (7th generation Core). With a refreshed design and featuring the new Spectre-specific HP logo, it is smaller, thinner, and adds a Thunderbolt 3 port. Spectre x360 15 with Kaby Lake was announced a few months later. The next revision came later in 2017 with 8th generation Core, and a 4K resolution touch display. Again, this was followed by a 15 inch variant introduced at CES 2018 featuring Gorilla Glass and support for the HP Tilt Pen. Updated models were released in October 2018 (13-inch) and January 2019 (15-inch) using 8th generation Refresh processors of Intel Core.
The 2019 version of Spectre x360 13 with 10th generation Intel Core has a smaller footprint compared to the previous, removing most bezels. The Spectre x360 15 debuted at CES 2020. In September 2020, a new generation Spectre x360 13 came using 11th generation Tiger Lake Core processors; a new Spectre x360 14 was also introduced, with a 3:2 ratio display measuring. A year later, Spectre x360 16, with a 16-inch screen, was introduced.
The line was updated to 12th generation Intel Core in May 2022. The previous generation's Spectre x360 13 (which had a 13.3" 16:9 display) and Spectre x360 14 (which had a 13.5" 3:2 display) were essentially replaced by a single Spectre x360 13.5 model (which HP also market as simply 'Spectre x360 2-in-1 Laptop'). 2024 saw the introduction of the next generation x360 models and the first with the Intel's Core Ultra branding.
Comparison table
Spectre x2
HP Spectre x2 (model no. 12-A) is a 12-inch convertible released in 2015 and features a fanless Intel Core M processor.
The second generation x2 (model no. 12-C) was announced in 2017. It moved away from the lower power Core M to the higher Core i series, offered up to i7. It has a 12.3-inch 3000x2000 IPS display.
Spectre 13
In 2016, HP unveiled the Spectre (model no. 13-V), which HP would later market as Spectre 13. With a thickness of 10.4 mm, HP called it the thinnest laptop ever. It also introduced with it the new alternative HP logo featuring thin lines which has since been adopted in some other products. A second generation (model no. 13-AF) came in 2017 with a reduced size and slimmer bezels.
Spectre Folio
HP announced the Spectre Folio (model no. 13-AK) in October 2018 made of metal and leather. It retailed starting from $1299, with the Core i7 and LTE edition selling for $1499.
Spectre Fold
In September 2023, the Spectre Fold foldable computer was introduced which HP call a "3-in-1" desktop, laptop and tablet.
References
Hewlett-Packard computers
Spectre
Consumer electronics brands
2-in-1 PCs
Ultrabooks
Computer-related introductions in 2012 | HP Spectre | [
"Technology"
] | 1,380 | [
"Crossover devices",
"2-in-1 PCs"
] |
56,302,227 | https://en.wikipedia.org/wiki/Abstract%20economy | In theoretical economics, an abstract economy (also called a generalized N-person game) is a model that generalizes both the standard model of an exchange economy in microeconomics, and the standard model of a game in game theory. An equilibrium in an abstract economy generalizes both a Walrasian equilibrium in microeconomics, and a Nash equilibrium in game-theory.
The concept was introduced by Gérard Debreu in 1952. He named it generalized N-person game, and proved the existence of equilibrium in this game. Later, Debreu and Kenneth Arrow (who renamed the concept to abstract economy) used this existence result to prove the existence of a Walrasian equilibrium (aka competitive equilibrium) in the Arrow–Debreu model. Later, Shafer and Sonnenschein extended both theorems to irrational agents - agents with non-transitive and non-complete preferences.
Abstract economy with utility functions
The general case
Definition
In the model of Debreu, an abstract economy contains a finite number N of agents. For each agent , there is:
A choice-set (a subset of some Euclidean space ). This represents the global set of choices that the agent can make.
We define the cartesian product of all choice sets as: .
An action-correspondence . This represents the set of possible actions the agent can take, given the choices of the other agents.
A utility function: , representing the utility that the agent receives from each combination of choices.
The goal of each agent is to choose an action that maximizes his utility.
Equilibrium
An equilibrium in an abstract economy is a vector of choices, , such that, for each agent , the action maximizes the function subject to the constraint :Equivalently, for each agent , there is no action such that: The following conditions are sufficient for the existence of equilibrium:
Each choice-set is compact, non-empty and convex.
Each action-correspondence is continuous, and its values are non-empty and convex.
Each utility function is continuous in and quasi-concave in .
The continuity conditions on the utility functions can be weakened as follows:
Each utility function is quasi-concave in , upper semi-continuous in , and graph continuous.
Another weakening, which does not use graph-continuity, is:
Each utility function is quasi-concave in , upper semi-continuous in , and the function [which is defined since is upper semi-continuous] is lower semi-continuous.
The proofs use the Kakutani fixed point theorem.
Exchange economy as a special case
Definition
An exchange economy is a system with N-1 consumers and homogeneous divisible goods. For each consumer i, there is:
A consumption-set (a subset of ). This represents the set of bundles that the agent can consume.
We define the cartesian product of all consumption sets as: .
An initial endowment vector
A utility function . This represents the preferences of the agent. Note that the utility of a consumer depends only on his own consumption, rather than on the entire allocation.
Define the set of possible price-vectors as: .
Equilibrium
A Walrasian equilibrium (aka competitive equilibrium) in an exchange economy is a vector of consumption-bundles and a price-vector, , such that:
The total consumption is at most the total endowment: .
The total expense of each agent is at most his budget: .
For each agent , the consumption maximizes the function subject to the constraint . I.e, if , then .
Reduction to abstract economy
Arrow and Debreu presented the following reduction from exchange economy to abstract economy.
Given an (N-1)-agent exchange economy, we define an N-agent abstract economy by adding a special agent called the market maker or market player. The "consumption" of this special player is denoted by p. The components of the abstract economy are defined as follows:
Each of the first N-1 agents has choice set , utility function , and action set defined by his budget: .
The market player has a choice set (the set of possible price-vectors), utility function , and action set defined by .
Intuitively, the market player chooses the price in a way that balances supply and demand: for commodities with more supply than demand, the right-hand term in is negative so the market player chooses a low price; for commodities with more demand than supply, the term is positive so the market player chooses a high price.
The following conditions in the exchange economy are sufficient to guarantee that the abstract economy satisfies the conditions for equilibrium:
Each consumption-set is compact and convex, and contains the endowment in its interior.
Each utility function is continuous and quasi-concave.
Moreover, the following additional condition is sufficient to guarantee that the equilibrium in the abstract economy corresponds to a competitive equilibrium in the exchange economy:
For every agent i, is not a local (unconstrained) maximum of . For example, it is sufficient to assume that all agents are not satiated.
The definition guarantees that the total expense of each agent is at most his budget. The definition guarantees that the consumption of each agent maximizes his utility given the budget. And the definition guarantees that the total consumption equals the total endowment.
Therefore, if the exchange economy satisfies the above three conditions, a competitive equilibrium exists.
In the proof we assumed that depends only on , but this assumption is not really needed: the proof remains valid even if the utility depends on the consumptions of other agents (externalities), or on the prices.
Abstract economy with preference correspondences
The general case
Definition
In the generalized model of Shafer and Sonnenschein, For each agent there is:
A choice-set - as above;
A constraint correspondence - as above;
A preference correspondence . This represents, for each combination of choices of the other agents, what choices the agent strictly prefers to his current choice.
The model of Debreu is a special case of this model, in which the preference correspondences are defined based on utility functions: . However, the generalized model does not require that the preference-correspondence can be represented by a utility function. In particular, it does not have to correspond to a transitive relation.
Equilibrium
An equilibrium in a generalized abstract economy is a vector of choices, , such that, for each agent , and . The equilibrium concept of Debreu is a special case of this equilibrium.
The following conditions are sufficient for the existence of equilibrium in the generalized abstract economy:
(a) Each choice-set is compact, non-empty and convex.
(b') Each action-correspondence is continuous.
(b'') The values are non-empty and convex for every x.
(c') Each preference-correspondence has an open graph in (this is a form of continuity condition).
(c'') For each , the convex hull of does not contain (this is a form of non-reflexivity condition: an agent does not strictly prefer a choice to itself).
Exchange economy as a special case
Definition
Mas-Colell generalized the definition of exchange economy in the following way. For every consumer i, there is:
A consumption-set - as above;
An initial endowment vector - as above;
A preference relation that can be equivalently represented by a preference-correspondence , that depends only on the consumed bundle: . Note the preference relation is not required to be complete or transitive.
Equilibrium
A competitive equilibrium in such exchange economy is defined by a price-vector p and an allocation y such that:
The sum of all prices is 1;
The sum of all allocations is at most the sum of endowments ;
For every i: ;
For every bundle z: if then (i.e., if the agent strictly prefers z to his share, then the agent cannot afford z).
Reduction to abstract economy
The "market maker" reduction shown above, from the exchange economy of Arrow-Debreu to the abstract economy of Debreu, can be done from the generalized exchange economy of Mas-Collel to the generalized abstract economy of Shafer-Sonnenschein. This reduction implies that the following conditions are sufficient for existence of competitive equilibrium in the generalized exchange economy:
Each is relatively-open (equivalently, each has an open graph);
For every bundle x, the set is convex and does not contain x (= irreflexivity). Mas-Collel added the condition that the set is non-empty (= non-saturation).
For every i: for some bundle x (this means that the initial endowment is in the interior of the choice-sets).
A negative example
The following example shows that, when the open graph property does not hold, equilibrium may fail to exist.
There is an economy with two goods, say apples and bananas. There are two agents with identical endowments (1,1). They have identical preferences, based on lexicographic ordering: for every vector of apples and bananas, the set , i.e., each agent wants as many apples as possible, and subject to that, as many bananas as possible. Note that represents a complete and transitive relation, but it does not have an open graph.
This economy does not have an equilibrium. Suppose by contradiction that an equilibrium exists. Then the allocation of each agent must be lexicographically at least (1,1). But this means that the allocations of both agents must be exactly (1,1). Now there are two cases: if the price of bananas is 0, then both agents can afford the bundle (1,2) which is strictly better than their allocation. If the price of bananas is some p > 0 (where the price of apples is normalized to 1), then both agents can afford the bundle (1+p, 0), which is strictly better than their allocation. In both cases it cannot be an equilibrium price.
Welfare theorems in abstract economies
Fon and Otani study extensions of welfare theorems to the generalized exchange economy of Mas-Collel. They make the following assumptions:
Each consumption-set is non-empty, convex, closed, and bounded below.
The preference correspondence is non-empty: (this is a non-saturation condition).
A competitive equilibrium is a price-vector and an allocation such that:
Feasibility: the sum of all allocations equals the sum of endowments (there is no free disposal);
Budget: for every i, ;
Preference: For every i, , where is the budget-set of i. In other words, for every bundle : if then (if the agent strictly prefers z to his share, then the agent cannot afford z).
A compensated equilibrium has the same feasibility and budget conditions, but instead of the preference condition, it satisfies:
Compensated Preference: For every i and for every bundle : if then .
A Pareto-optimal allocation is, as usual, an allocation without a Pareto-improvement. A Pareto-improvement of an allocation is defined as another allocation that is strictly better for a subset of the agents, and remains the same allocation for all other agents. That is:
for all .
Note that this definition is weaker than the usual definition of Pareto-optimality (the usual definition does not require that the bundles of other agents remain the same - only that their utility remains the same).
Fon and Otani prove the following theorems.
Every competitive equilibrium is Pareto-optimal.
Under certain conditions on the preferences, for every Pareto-optimal allocation, there exists a price-vector with which it is a compensated equilibrium.
See also
A further generalization of these equilibrium concepts for a general model without ordered preferences can be found in Barabolla (1985).
References
Market (economics)
Game theory equilibrium concepts
General equilibrium theory
Economy by field | Abstract economy | [
"Mathematics"
] | 2,402 | [
"Game theory",
"Game theory equilibrium concepts"
] |
56,302,435 | https://en.wikipedia.org/wiki/Phyllanthus%20distichus%20%28disambiguation%29 | The botanical name Phyllanthus distichus may refer to:
Phyllanthus distichus Hook. & Arn., a species of flowering plant found in the Hawaiian Islands
Phyllanthus distichus (L.) Müll.Arg., nom. illeg., a synonym of Phyllanthus acidus, native to Brazil | Phyllanthus distichus (disambiguation) | [
"Biology"
] | 78 | [
"Set index articles on plants",
"Set index articles on organisms",
"Plants"
] |
56,302,591 | https://en.wikipedia.org/wiki/Nodal%20decomposition | In category theory, an abstract mathematical discipline, a nodal decomposition of a morphism is a representation of as a product , where is a strong epimorphism, a bimorphism, and a strong monomorphism.
Uniqueness and notations
If it exists, the nodal decomposition is unique up to an isomorphism in the following sense: for any two nodal decompositions and there exist isomorphisms and such that
This property justifies some special notations for the elements of the nodal decomposition:
– here and are called the nodal coimage of , and the nodal image of , and the nodal reduced part of .
In these notations the nodal decomposition takes the form
Connection with the basic decomposition in pre-abelian categories
In a pre-abelian category each morphism has a standard decomposition
,
called the basic decomposition (here , , and are respectively the image, the coimage and the reduced part of the morphism ).
If a morphism in a pre-abelian category has a nodal decomposition, then there exist morphisms and which (being not necessarily isomorphisms) connect the nodal decomposition with the basic decomposition by the following identities:
Categories with nodal decomposition
A category is called a category with nodal decomposition if each morphism has a nodal decomposition in . This property plays an important role in constructing envelopes and refinements in .
In an abelian category the basic decomposition
is always nodal. As a corollary, all abelian categories have nodal decomposition.
If a pre-abelian category is linearly complete, well-powered in strong monomorphisms and co-well-powered in strong epimorphisms, then has nodal decomposition.
More generally, suppose a category is linearly complete, well-powered in strong monomorphisms, co-well-powered in strong epimorphisms, and in addition strong epimorphisms discern monomorphisms in , and, dually, strong monomorphisms discern epimorphisms in , then has nodal decomposition.
The category Ste of stereotype spaces (being non-abelian) has nodal decomposition, as well as the (non-additive) category SteAlg of stereotype algebras .
Notes
References
Category theory | Nodal decomposition | [
"Mathematics"
] | 473 | [
"Functions and mappings",
"Mathematical structures",
"Mathematical objects",
"Fields of abstract algebra",
"Category theory",
"Mathematical relations"
] |
71,952,501 | https://en.wikipedia.org/wiki/19%20to%20Zero | 19 to Zero is a Canadian not-for-profit behavioural sciences initiative based in Calgary, Alberta. Hosted at the University of Calgary, the public–private partnership is made up of around 500 members including public health specialists, academics, behavioural psychologists, marketers and multimedia creators. Its purpose is to increase confidence in vaccines for COVID-19 and other diseases by tackling vaccine hesitancy. The group publishes materials on its website and through partner organizations, including videos, billboards, presentations, brochures and in-person events.
History
Founding
19 to Zero was launched in August 2020 at the University of Calgary in order to influence the behaviour of the public surrounding public health measures and COVID-19 vaccines. The group's primary goal is to increase vaccine uptake in order to meet immunization targets, working to coordinate messaging among health care workers across Canada.
19 to Zero and the University of Toronto conducted a survey in the fall of 2020 to gauge routine vaccination rates following the declaration of the COVID-19 pandemic.
In September 2020, Alberta Innovates announced a $392,080 grant to fund 19 to Zero with a project titled "Changing COVID-19 Behaviors through a data-driven targeted marketing campaign."
19 to Zero collaborated in the development of the University of Calgary School of Public Policy's Vaccine Hesitancy Guide, and participated in the Faster Together program to "promote Covid-19 vaccine acceptance."
Community activation
On March 12, 2021, 19 to Zero hosted a webinar on vaccine hesitancy and COVID-19 conspiracy theories led by members of the Ontario COVID-19 Science Advisory Table, Queen's University, University of Waterloo and Alberta Children's Hospital. A fundraiser led by the University of Calgary raised $86,825 towards supporting 19 to Zero's efforts against COVID-19 misinformation, falling short of its $100,000 goal. Beginning in April 2021, the Calgary chapter of the World Economic Forum's Global Shapers Community initiative supported 19 to Zero by hosting town hall sessions on COVID-19 vaccines.
Some of 19 to Zero's community engagement activities included handing out postcards with QR codes linking to available vaccination appointments.
In August 2021, Shoppers Drug Mart announced it was providing funding to 19 to Zero in order to increase delivery of COVID-19 vaccines to target hesitant populations. 19 to Zero also partnered with Suncor Energy, who contributed $150,000 to coordinate a local vaccination campaign. In October 2021, the group launched a new behaviour change campaign called "It's Never Too Late" following an "unprecedented surge" of admissions to intensive care units in Alberta. The campaign video was produced with Emergence Creative to increase "stalled" vaccination rates, and was accompanied by billboard advertisements.
Following Health Canada's approval of COVID-19 vaccines for children aged 6 months to 11 years old, 19 to Zero participated in an advertising campaign called "Max the Vax" alongside the Canadian Medical Association, York Region and the Ontario Association of Children's Aid Societies. In 2022, 19 to Zero received a total of $480,000 in grant funding from the Public Health Agency of Canada's Immunization Partnership Fund to enhance the role of schools in promoting vaccine acceptance among students, their families, and teachers.
Post-pandemic
On September 25, 2024, the Government of Alberta announced a $1.5 new million partnership with 19 to Zero and the Alberta Cancer Foundation to deploy mobile lung cancer screening units to remote Alberta communities.
Funding
As a not-for-profit organization, 19 to Zero's activities are funded by government grants, corporate sponsorship and in-kind donations. Financial supporters include Alberta Children's Hospital, Alberta Health Services, Alberta Innovates, AstraZeneca, BD, Canadian Institutes of Health Research, City University of New York, GlaxoSmithKline, Heart and Stroke Foundation of Canada, Hill+Knowlton Strategies, Kantar Group, Merck, Moderna, Novavax, Pfizer, Public Health Agency of Canada, Sanofi, Shaw, McMaster University, Ontario College of Pharmacists, University of Calgary, University of Toronto, Western Economic Diversification and Women's College Hospital.
Federal project grants
Organization
Leadership
19 to Zero was co-founded by Jia Hu and Theresa Tang. Jia Hu was a Medical Officer of Health with Alberta Health Services. Hu is the medical director in the Canadian division of Cleveland Clinic, having previously worked at McKinsey & Company consulting in the healthcare and pharmaceutical sectors. He sits on the board of directors for Partners In Health Canada, and has worked during the COVID-19 pandemic to ramp up testing, risk communications and contact tracing. He also developed a contact tracing app funded by Alberta Innovates, and published research on behaviour change strategies towards increasing uptake of COVID-19 vaccines among children and other target populations.
Partners
19 to Zero is partnered with government, academic and corporate organizations. The group leads the Canadian arm of the "COVID-19 New Vaccine Information, Communication, and Engagement" (CONVINCE) Initiative, a global collaboration between the CUNY Graduate School of Public Health & Health Policy, the London School of Hygiene and Tropical Medicine's Vaccine Confidence Project, and Wilton Park, an executive agency of the Foreign, Commonwealth and Development Office in the United Kingdom. 19 to Zero is a participating member of the Faster, Together vaccine promotion initiative.
19 to Zero partnered with IV.AI to analyze online social media conversations in order to generate models to combat misinformation and collect information about vaccine hesitancy narratives. The organization also provided support for the first mobile vaccination clinic in Alberta led by Alberta Health and the Business Council of Alberta. The Alberta Federation of Regulated Health Professionals lists 19 to Zero as one of its COVID-19 resource providers. Additional partners include:
References
External links
Official website
Health communication
Canadian health activists
Vaccine hesitancy
Misinformation
Public relations
COVID-19 misinformation
Behavioural sciences
COVID-19 pandemic | 19 to Zero | [
"Biology"
] | 1,252 | [
"Behavioural sciences",
"Behavior"
] |
71,952,883 | https://en.wikipedia.org/wiki/List%20of%20Art%20Deco%20architecture%20in%20Oklahoma | This is a list of buildings that are examples of the Art Deco architectural style in Oklahoma, United States.
Ardmore
Ardmore Municipal Auditorium, Ardmore, 1943
Hardy Murphy Coliseum, Ardmore, 1943
Tivoli Theatre, Ardmore, 1915 and 1935
YWCA, Ardmore, 1938
Clinton
Clinton Armory, Clinton, 1937
Fire Station, Clinton, 1930s
McLain Rogers Park, Clinton, 1934
Enid
102 Independence, Enid, 1938
113 North. Grand, Enid, 1940
115 North Grand, Enid, 1940
323 Broadway, Enid, 1938
Arcadia Theatre, 226 West Randolph Avenue, Enid, 1931
Broadway Tower, Enid, 1931
Cherokee Theatre (now retail), Enid, 1928
Enid Armory, Enid, 1936
Eugene S. Briggs Auditorium, Enid, 1957
Garfield County Courthouse, Enid, 1896 and 1930
Taft Elementary School, Enid, 1937
Triangle Business Center (former Bass Building), Enid, 1930
Woolworth's, Enid, 1910 and 1921
McAlester
110–114 East Choctaw (former Woolworth's), McAlester
International Temple, Supreme Assembly, Order of the Rainbow for Girls, McAlester, 1951
McAlester Armory, McAlester, 1936
McAlester Scottish Rite Temple, McAlester, 1907 and 1930
OKLA Theater, McAlester, 1931 and 1948
Muskogee
304 East Callahan, Muskogee, 1925
540 West Court (former Chrysler–DeSoto Dealership), Muskogee, 1948
Fire Station No. 3, Muskogee, 1940s
Fire Station No. 4, Muskogee, 1940s
Roxy Theatre, Muskogee, 1948
Norman
301–302 South Porter, Norman, 1930
747 Asp (former cleaner's), Norman, 1930
Boomer Theater, Norman, 1947
Cleveland County Courthouse, Norman, 1940
Corner Thomas Garage (now A-1 Automotive), Norman, 1940s
Hiland Dairy, Norman, 1940s
Logan Apartments, Norman
University Theatre, Norman, 1930
Varsity Theatre (now retail), Norman
Oklahoma City
100 Park Avenue Building, Oklahoma City, 1923
Agnew Theater, Oklahoma City, 1947
Borden's Dairy Building, Oklahoma City, 1947
Cain's Coffee Building, Oklahoma City, 1919
Century Building, Oklahoma City
Cheever's Flowers (now Cheever's Cafe), Oklahoma City, 1935
City Place Tower, Oklahoma City, 1931
Civic Center Music Hall, Oklahoma City, 1937
Doctors Building, Oklahoma City, 1948
Edmond Armory, Edmond, 1937
First National Center, Oklahoma City, 1931
Jewel Theater, Oklahoma City, 1931
Lawyers Title Building, Oklahoma City, 1930
Lyric at the Plaza Theater, Oklahoma City, 1935
May Theatre, Oklahoma City, 1946
Norton–Johnson Buick Company, Oklahoma City, 1930
Nuway Laundry & Cleaners, Oklahoma City, 1940s
Oklahoma County Courthouse, Oklahoma City, 1937
Oklahoma Opry, Oklahoma City, 1946
Raylyn Taylor Salon, Oklahoma City
Santa Fe Depot, Oklahoma City, 1934
Sewage Treatment Plant, Oklahoma City
Taft Middle School, Oklahoma City, 1931
United States Post Office, Courthouse, and Federal Office Building, Oklahoma City, 1912
Will Rogers Theater Events Center, Oklahoma City, 1946
Shawnee
Auditorium, Shawnee
Hornbeck Theatre, Shawnee, 1947
Pottawatomie County Courthouse, Shawnee, 1934
Tulsa
11th Street Bridge, Tulsa, 1916
Adah Robinson Residence, Tulsa, 1929
Art Deco Lofts and Apartments, Tulsa, 1929
Boston Avenue Methodist Church,Tulsa, 1929
Boulder on the Park, Tulsa, 1923
Brady Theater, Tulsa, 1910
Central High School, Tulsa, 1925
Christ the King Church, Tulsa, 1928
Cities Service Station #8, Tulsa, 1940
City Veterinary Hospital, Tulsa, 1942
Continental Supply Company Building, Tulsa, 1921
Day Building (now Nelson's Buffeteria), Tulsa, 1926
Eleventh Street Arkansas River Bridge, Tulsa, 1929
Expo Square Pavilion, Tulsa, 1932
Fawcett Building, Tulsa, 1926
Fire Station No. 13, Tulsa, 1931
Fleeger Residence, Tulsa, 1937
Guaranty Laundry, Tulsa, 1928
Hawks Ice Cream, Tulsa, 1948
Jesse D. Davis Residence, Tulsa, 1936
John Duncan Forsyth Residence, Tulsa, 1937
KVOO-TV Broadcast Facility, Tulsa, 1954
Marquette School, Tulsa, 1932
Mayo Motor Inn, Tulsa, 1950
McGay Residence, Tulsa, 1936
Merchant's Exhibit Building, Tulsa State Fairgrounds, Tulsa, 1930
Metropolitan Tulsa Transit Authority Transfer Center, Tulsa, 1999
Midwest Equitable Meter, Tulsa, 1929
Midwest Marble and Tile Building, Tulsa, 1945
Milady's Cleaners, Tulsa, 1930
National Guard Armory, Tulsa, 1942
National Supply Company (now U-Haul), Tulsa, 1930
Oak Lawn Cemetery Entrance Gates, Tulsa, 1930
Oklahoma Department of Transportation, Tulsa, 1940
Oklahoma Natural Gas Company Building, Tulsa, 1925
Page Warehouse, Tulsa, 1927
Petroleum Building, Tulsa, 1921
Philcade Building, Tulsa, 1931
Philtower Building, Tulsa, 1928
Phoenix Cleaners, Tulsa, 1937
Pythian Building, Tulsa, 1931
Riverside Studios, Tulsa, 1929
Service Pipeline Building (former ARCO Building), Tulsa, 1949
Sherman Residence, Tulsa, 1930s
Southwestern Bell Main Dial Building, Tulsa, 1924
Tulsa Club Building, Tulsa, 1927
Tulsa Fire Alarm Building, Tulsa, 1934
Tulsa Monument Company, Tulsa, 1936
Tulsa SPCA, Tulsa, 1931
Tulsa State Fairgrounds Pavilion, Tulsa, 1932
Tulsa Union Depot, Tulsa, 1931
Ungerman Residence, Tulsa, 1941
Warehouse Market, Tulsa, 1930
Webster High School, Tulsa, 1938
Westhope, Tulsa, 1929
Whentoff Residence, Tulsa, 1935
Will Rogers High School, Tulsa, 1939
Other cities
Adair County Courthouse, Stilwell, 1930
Allred Theatre, Pryor Creek, 1914 and 1942
Anadarko Armory, Anadarko, 1937
Armory, Cherokee
Atoka Armory, Atoka, 1936
Attucks School, Vinita, 1917
Avant's Cities Service Station, El Reno, 1933
Beard Motor Company, Bristol, 1947 and 1953
Bristow Firestone Service Station, Bristow, 1929
Campus Theatre, Stillwater, 1939
Canute Service Station, Canute, 1939
Central Fire Station, Ada
City Hall, Vinita
Claremore Auto Dealership, Claremore, 1930
Clayton High School Auditorium, Clayton, 1936
Bartlesville High School, Bartlesville, 1939
Grady County Courthouse, Chickasha, 1935
Gymnasium, Hennessey, 1941
Gymnasium, Pernell, 1941
Haskell County Courthouse, Stigler, 1931
Healdtown Armory, Healdtown, 1936
Holdenville Armory, Holdenville, 1936
Hominy Armory, Hominy, 1937
Hugo Armory, Hugo, 1936
Jefferson County Courthouse, Waurika, 1931
Kerr-Mac Service Station, Pauls Valley
Leachman Theatre (now a furniture showroom), Stillwater, 1948
Long Theatre, Keyes, 1947
Masonic Temple, Anadarko
Memorial Park Swimming Pool, Blackwell, 1940s
Minco Armory, Minco, 1936
Municipal Building, Fairview
Okmulgee Armory, Okmulgee, 1937
Page Memorial Library, Sand Springs, 1930
Pawnee County Courthouse, Pawnee, 1932
Pensacola Dam, between Disney and Langley, 1940
Poncan Theatre, Ponca City, 1927
Rialto Theatre, Alva, 1949
Roff Armory, Roff, 1937
Sallisaw High School, Sallisaw, 1939
Sayre Champlin Service Station, Sayre, 1934
Softener & Filter Unit, El Reno, 1930s or 1940s
Southwestern Bell Telephone Building, Stroud, 1929
Sulphur Armory, Sulphur, 1937
Tahlequah Armory, Tahlequah, 1937
Telephone Building, Waynoka
United States Post Office Coalgate, Coalgate, 1940
United States Post Office Hollis, Hollis, 1939
United States Post Office Nowata, Nowata, 1938
Wagoner Armory, Wagoner, 1938
Warren Theatre, Broken Arrow
Washita County Jail, Cordell
Washita Theatre, Chickasha, 1941
Weatherford Armory, Weatherford, 1937
Westland Theatre, Elk City, 1950
See also
List of Art Deco architecture
List of Art Deco architecture in the United States
References
"Architectural Surveys." Oklahoma Historical Society. Retrieved 2022-09-06.
"Art Deco & Streamline Moderne Buildings." Roadside Architecture.com. Retrieved 2019-01-03.
"Art Deco Buildings in Tulsa". Tulsa Preservation Commission. 2015-05-06. Retrieved 2019-01-03.
Cinema Treasures. Retrieved 2022-09-06
"Court House Lover". Flickr. Retrieved 2022-09-06
"New Deal Map". The Living New Deal. Retrieved 2020-12-25.
"SAH Archipedia". Society of Architectural Historians. Retrieved 2021-11-21.
External links
Art Deco
Lists of buildings and structures in Oklahoma | List of Art Deco architecture in Oklahoma | [
"Engineering"
] | 1,781 | [
"Architecture lists",
"Architecture"
] |
71,953,734 | https://en.wikipedia.org/wiki/Mating%20ball | Mating balls are a brief gregarious structure resulting from a mating behaviour wherein a large number of individuals cluster together while mating. It has been observed in various kinds of animals including toads, bees and wasps, and snakes such as garter snakes and anacondas. Often the ball consists of a single female and many males; a particularly asymmetrical case is that of the red-sided garter snakes which form each spring some of the most populous mating balls observed, in which as many as a hundred males try to reproduce with a single female.
Herptiles
As poikilotherms, reptiles and amphibians are susceptible to sluggishness from cold weather. This causes a sexual competition among the first individuals to emerge from brumation to successfully mate before competitors are fully active. Body contact between members of the ball conserves the group's heat to enable the activity of mating to continue. Mating ball behaviour has been observed in Thamnophis species, Cubophis vudii, Natrix natrix, Bufo bufo, Bufo boreas, and other species. In the context of amphibians, mating balls are sometimes known as 'multiple amplexus'.
Insects
Kevin M. O'Neill has observed mating balls in Bembecinus quinquespinosus. Habropoda miserabilis also mate in balls. The phenomenon has been observed infrequently in stoneflies, although it is thought that it may be more common than might be inferred from observations thus far. Japanese beetles also make large mating balls, of which the occurrence in human spaces contributes to their being commonly regarded as a pest species. Once the female emerges from the ground, she releases a pheromone which attracts other beetles to form the mating ball. These balls are unusual among insects in that there may be multiple females in each one.
See also
Nuptial flight
Group sex
Mate choice
References
mating systems | Mating ball | [
"Biology"
] | 400 | [
"Behavior",
"Mating systems",
"Mating"
] |
71,954,772 | https://en.wikipedia.org/wiki/Jan%20Vondr%C3%A1k | Jan Vondrák is a Czech applied mathematician and theoretical computer scientist. He has been a professor of mathematics at Stanford University since 2015. He was a research staff member in the theory group at the IBM Almaden Research Center from 2009 to 2015.
Vondrák completed a bachelor's degree in physics (1995) and an M.S. (1999) and Ph.D. (2007) in computer science at Charles University under advisor Martin Loebl. He met mathematician Maryam Mirzakhani in 2004 in Boston. Vondrák completed a Ph.D. in applied mathematics in 2005 at Massachusetts Institute of Technology under advisor Michel Goemans. He was a postdoctoral researcher in the theory group at Microsoft Research from 2005 to 2006. From 2006 to 2009, Vondrák was a postdoctoral teaching fellow at Princeton University. He married Mirzakhani in 2008 on a mountain in New Hampshire. They moved to California in 2009. Their daughter Anahita was born 2011. Mirzakhani died of breast cancer in 2017.
References
Living people
Year of birth missing (living people)
Place of birth missing (living people)
21st-century Czech mathematicians
Czech computer scientists
Applied mathematicians
Theoretical computer scientists
Charles University alumni
Massachusetts Institute of Technology alumni
Stanford University faculty
Czech emigrants to the United States | Jan Vondrák | [
"Mathematics"
] | 257 | [
"Applied mathematics",
"Applied mathematicians"
] |
71,956,349 | https://en.wikipedia.org/wiki/Aleksandr%20Popov%20%28chemist%29 | Alexander Nikiforovich Popov ( 1840 – 18 August 1881) was a Russian organic chemist. He taught chemistry at the University of Kazan and at the University of Warsaw. He discovered what is now called Popov's Rule (or Popoff's Rule) which states that in the oxidation of an unsymmetrical ketone, the cleavage of the C−CO bond so that the smaller alkyl group is retained.
Popov was born in Vitebsk where his father was a military officer. He studied at Kazan University and attended the chemistry lectures of A.M. Butlerov. Graduating in 1865 he worked as a chemical lab assistant and in 1868 received a master's degree and became a professor at the University of Warsaw. In 1871 he went to work in Bonn with August Kekulé and E.K. Theodor Zinkce. It was during this period that he established the so-called Popov's Rule on the oxidation of benzene homologues being directed to the carbon atom bonded directly to the ring. He received a doctorate in 1872 for work on ketone oxidation. He identified an ordering of stability of radicals based on his examination of oxidation of asymmetric ketones which has been called Popov's rule. He served in the Russo-Turkish War (1877-1878). He introduced the use of potassium dichromate (K2CrO7) and sulphuric acid as oxidation reagent in organic analysis.
References
1840 births
1881 deaths
Chemists from the Russian Empire
Russian organic chemists
Kazan Federal University alumni | Aleksandr Popov (chemist) | [
"Chemistry"
] | 324 | [
"Organic chemists",
"Russian organic chemists"
] |
71,957,559 | https://en.wikipedia.org/wiki/Favre%20averaging | Favre averaging is the density-weighted averaging method, used in variable density or compressible turbulent flows, in place of the Reynolds averaging. The method was introduced formally by the French physicist Alexandre Favre in 1965, although Osborne Reynolds had also already introduced the density-weighted averaging in 1895. The averaging results in a simplistic form for the nonlinear convective terms of the Navier-Stokes equations, at the expense of making the diffusion terms complicated.
Favre averaged variables
Favre averaging is carried out for all dynamical variables except the pressure. For the velocity components, , the Favre averaging is defined as:
where the overbar indicates the typical Reynolds averaging, the tilde denotes the Favre averaging and is the density field. The Favre decomposition of the velocity components is then written as:
where is the fluctuating part in the Favre averaging, which satisfies the condition , that is to say, . The normal Reynolds decomposition is given by , where is the fluctuating part in the Reynolds averaging, which satisfies the condition .
The Favre-averaged variables are more difficult to measure experimentally than the Reynolds-averaged ones, however, the two variables can be related in an exact manner if correlations between density and the fluctuating quantity is known; this is so because, we can write:
The advantage of Favre-averaged variables are clearly seen by taking the normal averaging of the term that appears in the convective term of the Navier-Stokes equations written in its conserved form. This is given by
As we can see, there are five terms in the averaging when expressed in terms of Reynolds-averaged variables, whereas we only have two terms when it is expressed in terms of Favre-averaged variables.
References
Fluid dynamics
Turbulence
Combustion | Favre averaging | [
"Chemistry",
"Engineering"
] | 363 | [
"Turbulence",
"Chemical engineering",
"Combustion",
"Piping",
"Fluid dynamics"
] |
71,958,845 | https://en.wikipedia.org/wiki/List%20of%20Art%20Deco%20architecture%20in%20Pennsylvania | This is a list of buildings that are examples of the Art Deco architectural style in Pennsylvania, United States.
Erie
Boston Store, Erie, 1929
Erie Armory, Erie, 1929
Erie Federal Courthouse, Erie, 1937
Renaissance Centre, Erie, 1925
Union Station, Erie, 1927
United States Post Office, Erie, 1945
Warner Theatre, Erie, 1931
Philadelphia
30th Street Station, Philadelphia, 1934
1616 Walnut Street Building, Philadelphia, 1929
1822 Spring Garden, Philadelphia, 1930s or 1940s
Academy at Palumbo, Queen Village, Philadelphia, 1930
Academy for the Middle Years Northwest Middle School, Philadelphia, 1896 and 1929
Beneficial Savings Bank, Philadelphia, 1946
Bodine High School for International Affairs, Northern Liberties, Philadelphia, 1924
Boyd Theatre, Philadelphia, 1928
Central High School, Logan, Philadelphia, 1937
Clara Barton School, Feltonville, Philadelphia, 1925
Crown Can Company Building, Juniata, Philadelphia
Delaplaine McDaniel School, Point Breeze, Philadelphia, 1935–1937
Drake Hotel, Philadelphia, 1928
Edward W. Bok Technical High School, Philadelphia, 1938
Edwin Forrest School, Mayfair, Philadelphia, 1929
Edwin M. Stanton School, Southwest Center City, Philadelphia, 1926
Ethan Allen School, Mayfair, Philadelphia, 1930
Francis Hopkinson School, Juniata, Philadelphia, 1927
G.W. Childs Elementary School, Point Breeze, Philadelphia, 1908 and 1927
Gen. John F. Reynolds School, Philadelphia, 1926
George Meade School, North Central, Philadelphia, 1936
George W. Nebinger Elementary School, Bella Vista, Philadelphia, 1925
Hajoca Corporation Headquarters and Showroom, University City, Philadelphia, 1921 and 1930
James J. Sullivan School, Frankford, Philadelphia, 1930
Jim's Steaks, Philadelphia
John Bartram High School, Southwest Philadelphia, Philadelphia, 1939
Joseph H. Brown Elementary School, Holmesburg, Philadelphia, 1937
Joseph W. Catharine School, Mount Moriah, Philadelphia, 1938
Lewis Tower, Center City, Philadelphia, 1929
Lydia Darrah School, Francisville, Philadelphia, 1927
Market Street National Bank (now Marriott Residence Inn), Philadelphia, 1929
Mary Channing Wister School, Poplar, Philadelphia, 1926
Murrell Dobbins Career and Technical Education High School, North Philadelphia, Philadelphia, 1937
National Bank of North Philadelphia, Nicetown–Tioga, Philadelphia, 1928
Naval Hospital Philadelphia, Philadelphia, 1935
Nix Federal Building, Philadelphia, 1941
One South Broad, Center City, Philadelphia, 1932
Our Lady of Loreto Church, Philadelphia, 1938
Paul Lawrence Dunbar School, Templetown, Philadelphia, 1932
Pennsylvania Railroad Freight Building, University City, Philadelphia, 1929
Penypack Theatre, Holmesburg, Philadelphia, 1929
Philadelphia Museum of Art Perelman Building Philadelphia, 1926
Philadelphia Quartermaster Depot, Philadelphia, 1799 and 1926
Philadelphia School of Occupational Therapy, Philadelphia, 1929
Robert Fulton School, Morton, Philadelphia, 1937
Roberts Vaux Junior High School, North Central, Philadelphia, 1938
Sedgwick Theater, Mount Airy, Philadelphia, 1928
Special Troops Armory, Ogontz, Philadelphia, 1938
Spring Garden School, Poplar, Philadelphia, 1931
Suburban Station, Penn Station, Philadelphia, 1934
Sun Oil Building, Center City, Philadelphia, 1928
Terminal Commerce Building, Callowhill, Philadelphia, 1931
Thomas K. Finletter School, Olney, Philadelphia, 1930
Tindley Temple United Methodist Church, Southwest Center City, Philadelphia, 1923
United States Court House and Post Office, Philadelphia, 1930s
United States Custom House, Philadelphia, 1934
United States Post Office–Main Branch, Philadelphia, 1931–1935
Uptown Theater, Philadelphia, 1927
Vare-Washington School, Dickinson Narrows, Philadelphia, 1937
WCAU TV Building, 1622 Chestnut Street, Philadelphia, 1928
William M. Meredith School, Queens Village, Philadelphia, 1931
YMCA Philadelphia, Philadelphia, 1926
Pittsburgh
Bell Telephone Building, Downtown Pittsburgh, Pittsburgh, 1923
Brighton Theater (now NALC Branch), Pittsburgh, 1928
Cathedral of Learning, Pittsburgh, 1937
Conroy Education Center, Pittsburgh, 1895
EQT Plaza, Downtown Pittsburgh, Pittsburgh, 1984
Fulton Elementary School, Highland Park, Pittsburgh, 1894 and 1929
Grant Building, Downtown Pittsburgh, Pittsburgh, 1929
Gulf Tower, Downtown Pittsburgh, Pittsburgh, 1932
Highland Towers Apartments, Shadyside, Pittsburgh, 1913
Knoxville Junior High School, Knoxville, Pittsburgh, 1927
Koppers Building, Pittsburgh, 1929
Larimer School, Larimer, Pittsburgh, 1896 and 1931
Lemington Elementary School, Pittsburgh, 1937
Letsche Elementary School, Pittsburgh, 1905
Lincoln Elementary School, Larimer, Pittsburgh, 1931
Madison Elementary School, Upper Hill, Pittsburgh, 1902 and 1929
Medical Arts Building, University of Pittsburgh Medical Center, Pittsburgh, 1931
Mifflin Elementary School, Pittsburgh, 1932
New Granada Theater, Hill District, Pittsburgh, 1928
Oliver High School, Pittsburgh, 1925
Omni William Penn Hotel, Downtown Pittsburgh, Pittsburgh, 1916 and 1929
Prospect Junior High and Elementary School, Mount Washington, Pittsburgh, 1931
Salk Hall, University of Pittsburgh, Pittsburgh, 1941
Schiller Elementary School, East Allegheny, Pittsburgh, 1939
Thaddeus Stevens Elementary School, Elliott, Pittsburgh, 1939
Washington Education Center, Pittsburgh, 1936
Western Psychiatric Institute and Clinic, Pittsburgh, 1938–1940
Whitehill-Gleason Motors, East Liberty, Pittsburgh, 1920
Reading
Astor Theater, Reading, 1928
Berks County Courthouse, Reading, 1932
Hotel Abraham Lincoln, Reading, 1930
York
Mt. Rose School, York
Valencia Ballroom, York, 1930s
York Hospital, York
York Telephone and Telegraph Building, York
Other cities
1419 Darby Road, Havertown, 1945
Allegheny County Airport, West Mifflin, 1931
Allen Theatre, Annville
Altoona Armory, Logan Township, 1938
Alvina Krause Theatre (former Columbia Theatre), Bloomsburg, 1940
Anthony Wayne Theatre, Wayne, 1928
Arcadia Theatre, Wellsboro, 1921
Berwick Theatre, Berwick, 1926
Bethlehem Armory, Bethlehem, 1930
Bradfords Main Street Movie House, Bradford, 1935
Butler Armory, Butler, 1922, 1930
Campus Theatre, Lewisburg Historic District, Lewisburg, 1941
Carlisle Theatre, Carlisle, 1939
Civic Theatre of Allentown, Allentown, 1928
Clearfield Armory, Lawrence Township, 1938
Coraopolis Armory, Coraopolis, 1938
County Cinema, Doylestown Historic District, Doylestown, 1938
Dime Savings and Trust Company, Allentown, 1925
Easton National Bank, Easton Historic District, Eaton Township, 1929
F M. Kirby Center, Wilkes-Barre, 1938
Farmers National Bank, Bloomsburg, 1941
First National Bank of Leechburg, Leechburg, late 1920s
Gettysburg Armory, Gettysburg, 1938
Hamburg Armory, Hamburg, 1939
Hiway Theatre, Jenkintown, 1925
Huntingdon Armory, Huntingdon, 1930 and 1937
Jacob Mayer Building, Easton Historic District, Easton, 1930s
John Henry Neff Elementary School, Lancaster, 1930s
J.P. McCaskey High School, Lancaster, 1938
Kane Armory, Kane, 1922
Latrobe Armory, Latrobe, 1928
Leader Building, Jacobus
Lewisburg Armory, East Buffalo Township, 1938
Ligonier Armory, Ligonier, 1938
Montgomery Ward Building, Lewiston, 1929
Moose Lodge, Williamsport, 1940
Mount St. Peter Church, New Kensington, 1942
The Movies (former Sauconia Theatre), Hellertown, 1940 and 1968
N. N. Moss Building, Greenville, 1920
New Castle Armory, Shenango Township, 1938
Paxton Municipal Building, Harrisburg, 1930s
Pennsylvania Farm Show Complex & Expo Center, Harrisburg, 1931
Roxy Theatre (former Dreamland Theatre), Lock Haven, 1924 and 1931
Royer Pharmacy, Ephrata, 1938
Scottdale Armory, Scottdale, 1929
Strawbridge & Clothier, Jenkinton, 1931 and 1954
Union National Bank of Mahanoy City, Mahanoy City, 1922
Warner Theater, West Chester, 1930
Waynesboro Armory, Waynesboro, 1938
Wellsboro Armory, Wellsboro, 1932
William J. Nealon Federal Building and United States Courthouse, Scranton, 1931
Williamsport Armory, Williamsport, 1927
See also
List of Art Deco architecture
List of Art Deco architecture in the United States
References
"Art Deco & Streamline Moderne Buildings." Roadside Architecture.com. Retrieved 2019-01-03.
Cinema Treasures. Retrieved 2022-09-06
"Court House Lover". Flickr. Retrieved 2022-09-06
Fanning, Colin. "Art Deco" Encyclopedia of Greater Philadelphia. Retrieved 2019-01-03.
"New Deal Map". The Living New Deal. Retrieved 2020-12-25.
"SAH Archipedia". Society of Architectural Historians. Retrieved 2021-11-21.
External links
Art Deco
Lists of buildings and structures in Pennsylvania | List of Art Deco architecture in Pennsylvania | [
"Engineering"
] | 1,727 | [
"Architecture lists",
"Architecture"
] |
71,959,012 | https://en.wikipedia.org/wiki/List%20of%20Art%20Deco%20architecture%20in%20Virginia | This is a list of buildings that are examples of the Art Deco architectural style in Virginia, United States.
Alexandria
Arlandria Floors Building, Garage, Del Ray, Alexandria, 1941
Bowman's Drugstore, Del Ray, Alexandria, 1941
Chesapeake & Potomac Telephone Co. of Virginia Building, Del Ray, Alexandria, 1940 and 1947
Del Ray Building, Del Ray, Alexandria, 1938
George Washington Middle School, Del Ray, Alexandria, 1936
Glendale Garden Apartments, Del Ray, Alexandria, 1937
Leslie Avenue/Monroe Avenue Warehouses ( now Swing Coffee), Del Ray, Alexandria, 1952
Palm Theatre and Guild Theatre, Del Ray, Alexandria, 1923, 1955
Poladian Building, Del Ray, Alexandria, 1939, 1947
Torpedo Factory Art Center, Old Town, Alexandria, 1918 and 1930s
Walgreens Building, Del Ray, Alexandria, 1941
Arlington County
Arlington Cinema 'N' Drafthouse, Arlington Country, 1939
Calvert Manor, Arlington Country, 1948
Cherrydale Auto Parts (former Progressive Cleaners), Arlington Country, 1939
Glebe Center, Arlington Country, 1940
Lee Garden Apartments, Arlington Country
Wakefield Manor, Arlington Country, 1943
Washington-Liberty High School addition, Arlington Country, 1938
Blacksburg
Blacksburg Motor Company, Inc., Blacksburg, 1923 and 1933
Lyric Theatre, Blacksburg, 1930
National Bank of Blacksburg, Blacksburg, 1941
Lynchburg
Allied Arts Building, Lynchburg, 1931
Armstrong Elementary School, Lynchburg, 1954
Lynchburg News & Daily Advance Building, Lynchburg, 1931
Pyramid Motors, Lynchburg, 1937
Norfolk
Ocean View Elementary School, Norfolk, 1939
Walter E. Hoffman United States Courthouse, Norfolk, 1932
York Center, Norfolk, 1924
Portsmouth
Commodore Theatre, Portsmouth, 1945
Governor Dinwiddie Hotel and Suites, Portsmouth, 1945
National Guard Armory, Portsmouth, 1936
Richmond
3500 Center (Seaboard Airline Railroad Co), Scott's Addition, 1956
718 East Franklin Street, Richmond, 1951
A&P Building (Scott's Addition Animal Hospital), 1938
Altamont Apartments, Scott's Addition, 1929
Auto Repair Garage, Scott's Addition, 1941
Bank of Virginia (Comedy Club), Grace Street, 1949
Bausch & Lombe, Richmond, 1940
Blanchard's Coffee, Scott's Addition, 1930s
Cary Street Park and Shop Center, Richmond, 1938
Central National Bank Richmond, 1929
C. P. Dean (Mosaic Catering), Scott's Addition, 1930
Chesapeake & Potomac Telephone Company (Verizon Building), 1929
Commercial Building, Scott's Addition, 1932
Commercial Buildings, Grace Street, 1932
Curles Neck Dairy Sales & Distribution, Scott's Addition, 1939 (Bernie Sanders mural)
Dooley wing lobby, Richmond Public Library, 1930
East End Theatre, Church Hill North, 1936-1938
Franklin Federal Savings and Loan Company (Capitol Thrift), 1940
Hand Craft Services, Scott's Addition, 1946
Havens & Martins Inc. Radio/WMBG (WTVRCBS6), Scott's Addition, 1938
The Hippodrome, Richmond, 1946
Investment Realty Company (Perly's), Grace Street, 1930
Lewis F. Powell Jr. United States Courthouse Annex (former Parcel Post Building), Richmond, 1929
Maggie Walker High School, Richmond,1936
Miller and Rhoads (Hilton), Richmond, 1930 update
Model Office Park, Richmond, 1939
Model Tobacco Building, Richmond, 1940
Moving and Storage Transport Station (Ardent), Scott's Addition, 1940s
Nolde Brothers Bakery, Richmond, 1926
O. P. Brisner store, 208 East Grace Street, Richmond, 1930
P. C. Abbott Store (Silk Trading), Richmond, 1930
R. McGuire Steinruck Used Car Showroom, Scott's Addition, 1951
Richmond Storage and Service Garage, 1928
Robinson Theatre, Richmond, 1937
Syndlor and Hundley Building, Grace Street, 1931
Thomas Jefferson High School, Richmond, 1929
Verizon Building Annex, Richmond, 1949
Virginia State Library (Patrick Henry Building), 1938
W. J. Anderson, Richmond, 1929
W. T. Grant (Subway), Richmond, 1939
West Hospital, Richmond, 1940
Roanoke
425 Campbell Avenue, Roanoke, 1934
1306 Grandin Road, Roanoke, 1926
Appalachian Electric Power Building, Roanoke, 1947
Claytor Memorial Clinic, Roanoke, 1947
Community Inn, Roanoke, 1929
The Cornerstone, Roanoke, 1923
General Office Building-North, Roanoke, 1931
Grand Piano, N.W. Pugh & Company Department Store, Roanoke, 1930
Mick-or-Mack Grocery, Roanoke, 1953
Norfolk & Southern Railroad Office, Roanoke
Ponce De Leon Hotel, Roanoke, 1931
Professional Arts Building, Roanoke, 1929
Roanoke Apartments, Roanoke, 1950
Roanoke Passenger Station, Roanoke, 1949
Roanoke Higher Education Center, Roanoke, 1931
Television Center, Roanoke, 1955
Walker Condos, Roanoke, 1937
Other cities
29 Diner, Fairfax, 1947
Ashland Theatre Ashland, 1948
Beacon Theatre, Hopewell, 1928
Carl's Ice Cream, Fredericksburg, 1947
Central High School, Painter, 1932
Charlottesville Coca-Cola Bottling Works, Charlottesville, 1939
Donk's Theatre, Hudgins, 1947
Emporia Armory, Emporia, 1936
Executive Plaza, Bristol, 1925
Frost Diner, Warrenton, 1946
Hampton City Hall, Hampton, 1939
Henrico Theatre, Highland Springs, 1938
Hotel Warwick, Newport News, 1928
Island Roxy, Chincoteague, 1945
Lincoln Theatre, Marion, 1929
New Hope High School, New Hope, 1925
Palace Theatre, Cape Charles, 1941
Pitts Theatre, Culpepper, 1937
Randolph Hotel, Hopewell, 1927
Royal Clipper Inn & Suites, Virginia Beach, 1980
Shenandoah Motel, Front Royal, 1950
StellarOne Bank Building, Rocky Mount, 1928
Visulite Theatre, Staunton, 1937
Walker–Grant School, Fredericksburg, 1938
Whittaker Memorial Hospital, Newport News, 1943
Winchester Coca-Cola Bottling Works, Winchester, 1941
See also
List of Art Deco architecture
List of Art Deco architecture in the United States
References
"Art Deco & Streamline Moderne Buildings." Roadside Architecture.com. Retrieved 2019-01-03.
Cinema Treasures. Retrieved 2022-09-06
"Court House Lover". Flickr. Retrieved 2022-09-06
"New Deal Map". The Living New Deal. Retrieved 2020-12-25.
"SAH Archipedia". Society of Architectural Historians. Retrieved 2021-11-21.
External links
Art Deco
Lists of buildings and structures in Virginia | List of Art Deco architecture in Virginia | [
"Engineering"
] | 1,307 | [
"Architecture lists",
"Architecture"
] |
71,961,383 | https://en.wikipedia.org/wiki/HD%20101782 | HD 101782, also known as HR 4507, is a yellowish-orange hued star located in the southern circumpolar constellation of Chamaeleon. It has an apparent magnitude of 6.33, placing it near the limit for naked eye visibility. Based on parallax measurements from Gaia DR3, the object is estimated to be 356 light years away from the Solar System. It appears to be receding with a heliocentric radial velocity of . De Mederios found the radial velocity to be variable, suggesting that it may be a spectroscopic binary. Eggen (1989) lists it as a member of the young disk population.
HD 101782 has a stellar classification of K0 III, indicating that it is an evolved red giant. It is currently on the horizontal branch (HB), fusing helium at its core. The star is located on the cool end of the red clump, a region on the HR diagram with metal-rich HB stars. It has double the mass of the Sun but has expanded to 10.1 times its girth. It radiates 55 times the luminosity of the Sun from its photosphere at an effective temperature of . It has an iron abundance 110% that of the Sun's, placing it at solar metallicity. Like most giants it spins slowly, having a projected rotational velocity lower than .
TYC 9507-3649-1 is a 10th magnitude optical companion located away along a position angle of 139°. This companion was first noticed by Sir John Herschel in 1837.
References
K-type giants
Horizontal-branch stars
Double stars
101782
Chamaeleon
056996
4507
CD-82 00224
Chamaeleontis, 33 | HD 101782 | [
"Astronomy"
] | 366 | [
"Chamaeleon",
"Constellations"
] |
71,964,454 | https://en.wikipedia.org/wiki/Gravitational%20scattering | Gravitational scattering refers to the process by which two or more celestial objects interact through their gravitational fields, causing their trajectories to alter. This phenomenon is fundamental in astrophysics and the study of dynamic systems. When objects like stars, planets, or black holes pass close enough to influence each other’s motions, their paths can shift dramatically. These interactions typically result in either bound systems, like binary star systems, or unbound systems, where the objects continue moving apart after the interaction. An example of a body ejected from a planetary system by this process would be Kuiper belt bodies pushed from the Solar System by Jupiter.
Observing gravitational scattering
Gravitational scattering events are usually studied using simulations and mathematical models of the gravitational field interactions between bodies. One significant feature of gravitational scattering is the effect of energy exchange. For instance, a high-velocity object may transfer some of its kinetic energy to a slower-moving object, resulting in a slingshot effect. This principle is utilized in space exploration for gravitational assists, where spacecraft gain momentum by passing close to a planet.
Observing gravitational scattering has provided insight into many astrophysical phenomena. In dense regions like star clusters or galactic cores, gravitational scattering plays a role in star formation and the distribution of stellar populations. For instance, hypervelocity stars, which are ejected from their galaxies, are often a result of gravitational scattering involving massive objects like black holes. In more extreme cases, close interactions between compact objects, such as black holes, can lead to the emission of gravitational waves, detectable by instruments like the Laser Interferometer Gravitational-Wave Observatory (LIGO).
Gravitational scattering is analyzed through both Newtonian mechanics and general relativity, with the latter being necessary for systems involving high mass or velocity.
Gravitational scattering impacts
Gravitational scattering can cause orbits to change or even cause celestial bodies to depart their native planetary systems. A possible mechanism that may move planets over large orbital radii is gravitational scattering by larger planets or, in a protoplanetary disk, gravitational scattering by over-densities in the fluid of the disk. In the case of the Solar System, Uranus and Neptune may have been gravitationally scattered onto larger orbits by close encounters with Jupiter and/or Saturn. Systems of exoplanets can undergo similar dynamical instabilities following the dissipation of the gas disk that alter their orbits and in some cases result in planets being ejected or colliding with the star.
Planets scattered gravitationally can end on highly eccentric orbits with perihelia close to the star, enabling their orbits to be altered by the gravitational tides they raise on the star. The eccentricities and inclinations of these planets are also excited during these encounters, providing one possible explanation for the observed eccentricity distribution of the closely orbiting exoplanets. The resulting systems are often near the limits of stability. As in the Nice model, systems of exoplanets with an outer disk of planetesimals can also undergo dynamical instabilities following resonance crossings during planetesimal-driven migration. The eccentricities and inclinations of the planets on distant orbits can be damped by dynamical friction with the planetesimals with the final values depending on the relative masses of the disk and the planets that had gravitational encounters.
See also
Planetary migration
References
Astrophysics
Effects of gravity | Gravitational scattering | [
"Physics",
"Astronomy",
"Mathematics",
"Engineering"
] | 669 | [
"Astrodynamics",
"Classical mechanics",
"Astrophysics",
"Astronomical dynamical systems",
"Aerospace engineering",
"Dynamical systems",
"Celestial mechanics",
"Astronomical objects",
"Astronomical sub-disciplines",
"Stellar dynamics"
] |
71,964,566 | https://en.wikipedia.org/wiki/Offshore%20freshened%20groundwater | Offshore freshened groundwater (OFG) is water that contains a Total Dissolved Solid (TDS) concentration lower than sea water, and which is hosted in porous sediments and rocks located in the sub-seafloor. OFG systems have been documented all over around the world and have an estimated global volume of around 1 × 106 km3. Their study is important because they may represent an unconventional source of potable water for human populations living near the coast, especially in areas where groundwater resources are scarce or facing stress
Elements and processes
OFG usually presents salinity values < 33 Practical Salinity Units (PSU). They are located at water depth < 100 m and within 55 km of the coast in both siliciclastic and carbonatic aquifers along active and passive margins. OFG systems are usually composed by multiple OFG bodies which are altogether < 2 km thick (Fig.1)
The principal emplacement mechanisms for OFG systems are (from the most common to the least common):
Meteoric recharge by rainfall which can be either a paleo-meteoric event during sea level low stands or an active-meteoric recharge via permeable connections between offshore and onshore aquifers (Fig. 2).
Diagenesis due to post‐sedimentary alteration processes leading the release of freshwater and accumulation in deeply buried marine sediments in high Pressure and Temperature conditions .
Sub‐glacial and pro‐glacial injection such as sub-glacial melting, sub-glacial drainage systems, reversal of groundwater flow direction with respect to modern flow patterns.
Decomposition of gas hydrates as a result of changing in temperatures or pressures which lead to the release of low salinity pore water.
The geological settings have a major control on OFG development: the majority are hosted in coarser siliciclastic materials, with porosity values around 30% to 60%, constraint by a permeability contrast (predominantly sand to clay). Topographic gradients have a major impact on OFG emplacement as topography-driven flow is one of the most important mechanisms controlling discharge of freshwater offshore.
Investigation
Different methods can be used to characterize and assess OFG occurrences:
Drilling, coring and wireline logging methods lead to characterized both sediments (e.g. granulometry and hydraulic properties) and pore water via geochemical analysis (e.g. salinity and chloride concentrations). Resistivity, porosity, density, sonic velocities, gamma ray content, temperature, and flow meter measurements can be then determined via in-situ measurements.
Reflection seismic methods provide indirect constraints on heterogeneities controlling OFG distribution. Electromagnetic (EM) surveying, usually collected using controlled source electromagnetic (CSEM) systems, is used to discriminate between saturated regions with saline water (less resistive) from those containing fresh groundwater (more resistive) (Fig. 3).
Numerical modelling approaches can lead to quantifying OFG emplacement in continental shelf environments over geologic time scales
Applications and potential of OFG
OFG systems are receiving increasing attention as they may be used as an unconventional source of potable water in coastal areas, where groundwater resources are being rapidly depleted or contaminated. 60% of the global population lives in areas of water stress defined as the ratio of total water withdrawals to available renewable surface and groundwater supplies (Fig.1). Climate change, rapid population growth, and urbanization have a negative impact on water stress especially in coastal communities. Therefore, OFG has been proposed as an alternative source of freshwater to mitigate water scarcity and groundwater depletion in areas of water stress
References
Marine geology
Hydrology
Water | Offshore freshened groundwater | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 749 | [
"Water",
"Hydrology",
"Environmental engineering"
] |
71,965,326 | https://en.wikipedia.org/wiki/Oper%20%28mathematics%29 | In mathematics, an oper is a principal connection, or in more elementary terms a type of differential operator. They were first defined and used by Vladimir Drinfeld and Vladimir Sokolov to study how the KdV equation and related integrable PDEs correspond to algebraic structures known as Kac–Moody algebras. Their modern formulation is due to Drinfeld and Alexander Beilinson.
History
Opers were first defined, although not named, in a 1981 Russian paper by Drinfeld and Sokolov on Equations of Korteweg–de Vries type, and simple Lie algebras. They were later generalized by Drinfeld and Beilinson in 1993, later published as an e-print in 2005.
Formulation
Abstract
Let be a connected reductive group over the complex plane , with a distinguished Borel subgroup . Set , so that is the Cartan group.
Denote by and the corresponding Lie algebras. There is an open -orbit consisting of vectors stabilized by the radical such that all of their negative simple-root components are non-zero.
Let be a smooth curve.
A G-oper on is a triple where is a principal -bundle, is a connection on and is a -reduction of , such that the one-form takes values in .
Example
Fix the Riemann sphere. Working at the level of the algebras, fix , which can be identified with the space of traceless complex matrices. Since has only one (complex) dimension, a one-form has only one component, and so an -valued one form is locally described by a matrix of functions
where are allowed to be meromorphic functions.
Denote by the space of valued meromorphic functions together with an action by , meromorphic functions valued in the associated Lie group . The action is by a formal gauge transformation:
Then opers are defined in terms of a subspace of these connections. Denote by
the space of connections with . Denote by the subgroup of meromorphic functions valued in of the form
with meromorphic.
Then for it holds that . It therefore defines an action. The orbits of this action concretely characterize opers. However, generally this description only holds locally and not necessarily globally.
Gaudin model
Opers on have been used by Boris Feigin, Edward Frenkel and Nicolai Reshetikhin to characterize the spectrum of the Gaudin model.
Specifically, for a -Gaudin model, and defining as the Langlands dual algebra, there is a bijection between the spectrum of the Gaudin algebra generated by operators defined in the Gaudin model and an algebraic variety of opers.
References
Differential operators
Connection (mathematics) | Oper (mathematics) | [
"Mathematics"
] | 542 | [
"Mathematical analysis",
"Differential operators"
] |
71,965,870 | https://en.wikipedia.org/wiki/1D-LSD | 1D-LSD (1-(1,2-dimethylcyclobutane-1-carbonyl)-lysergic acid diethylamide, SYN-L-229) is a psychotropic substance and a research chemical that has potential psychedelic effects. It is believed to be a prodrug for LSD and has replaced 1V-LSD in Germany after 1V-LSD became covered by the German NpSG law in 2022. It is also available as tartrate and liquid.
Legality
Germany
Since the 14 June 2024 1D-LSD (and 1T-LSD) are covered by the German NpSG law.
Austria
According to the current legal situation, 1D-LSD is neither explicitly mentioned in the Narcotic Drugs Ordinance nor in the Psychotropic Substances Ordinance (SV/PV), thus it is neither to be classified as a narcotic drug in the sense of the SV nor as a psychotropic substance in the sense of the PV.
See also
1S-LSD
1DD-LSD
1V-LSD
1cP-LSD
1T-LSD
References
Designer drugs
Psychedelic drugs
Lysergamides
Prodrugs
Cyclobutanes | 1D-LSD | [
"Chemistry"
] | 261 | [
"Chemicals in medicine",
"Prodrugs"
] |
71,966,092 | https://en.wikipedia.org/wiki/Dinitroglycoluril | Dinitroglycoluril (DNGU) is a high explosive chemical compound with the formula C4H4N6O6. Dinitroglycoluril is of growing interest due to its stability, ability to mix with oxygen positive explosives to form composites, and it is a precursor to tetranitroglycoluril.
Preparation and decomposition
Dinitroglycoluril can be created by nitrating glycoluril with concentrated nitric acid.
The activation energy required to begin decomposition of dinitroglycoluril is 165 kJ/mol. When dinitroglycoluril is heated to 243 °C in an inert atmosphere, the two nitrate groups break off and the two central carbon atoms form a double bond.
Sensitivity
The impact sensitivity of dinitroglycoluril was determined using the Bruceton-staircase procedure, which found a h50 of 88 cm. Friction sensitivity was determined by a Julius-Peters apparatus, which found a sensitivity of 25 kg.
References
Explosive chemicals
Nitrogen heterocycles | Dinitroglycoluril | [
"Chemistry"
] | 220 | [
"Explosive chemicals"
] |
71,966,735 | https://en.wikipedia.org/wiki/VAMAS | VAMAS stands for Versailles Project on Advanced Materials and Standards. It is a collaborative project that was initiated at the 1982 G7 Economic Summit in Versailles to develop and promote standards for the characterisation of advanced materials, including surfaces, interfaces, thin films, and nanostructures. Using interlaboratory studies, the VAMAS project has developed a number of standard test methods and reference materials for a wide range of materials. These standards have been widely adopted by industry and academic researchers, and have contributed to the development of new materials and technologies.
History
G7 summits proposals
The Versailles project on advanced materials and standards (VAMAS) was first proposed, among 18 other projects, at the 1982 G7 Economic Summit held at the Palace of Versailles.
However the proposal materialised during the 1983 G7 summit in the US where there was a focus on issues related to science and technology. During that meeting, the attendees acknowledged the importance of collaborating in the field of science and technology. The proposals for cooperation came from the French President François Mitterrand, which were presented in a lengthy speech highlighting the necessity of creating a new international division of labour for technology.
The proposal was met with scepticism from the US, but George A. Keyworth, director of the White House's Office of Science and Technology Policy (OSTP), was enthusiastic about the idea of international cooperation in science and technology. He argued that the massive cost of experimental facilities in areas such as high-energy physics and fusion research made international collaboration desirable. Both Europe and the United States were spending approximately half a billion dollars a year on controlled fusion, with Japan spending another quarter of a million dollars. Keyworth believed that this highly redundant research could be avoided with greater collaboration.
"The single most important outcome [of the initiative] is that science and technology have been discussed at two successive summits by the heads of state," says Robin Nicholson, chief scientific adviser to British Prime Minister Margaret Thatcher. "That has never happened before, and it must be significant for science and technology that it is happening now."
The French, under the guidance of President Mitterrand's personal adviser, Jacques Attali, who chaired the Versailles working group, provided a more pragmatic approach to the working groups to bridge the political gap between Mitterrand's interventionist position, broadly supported by Japan and Italy, and the United States' free-trade position, adopted by West Germany and the United Kingdom. The working group included a reference to the need to restrict the transfer of militarily technology to Soviet bloc.
During the summits, the Working Group on Science and Technology proposed 18 specific cooperation projects, with one or more of the seven nations and the European Economic Community taking organising responsibility for each project. The projects included high-energy physics, solar system exploration, remote sensing from space, advanced robotics, biological sciences, photosynthesis, the impact of new technologies on mature industries, high-speed ground transportation, public acceptance of new technologies, and aquiculture.
The United States declined to participate in projects in which it claimed government actions could impinge on the interests of the private sector, including the biotechnology project, which was led by France and generated the most controversy. Initially, France and Japan argued strongly for the internationalisation of biotechnology research. The UK requested to co-lead the biotechnology subject with France, but France's interest in the subject was criticised as "idiosyncratic" by the UK Chief Scientist.
The UK also nominated a Working Group to report on the theme of collaborative projects relating to "Technology, Growth and Employment," which developed the "Materials research and development" project that was jointly led by the UK and the US. This last project became the "Versailles Project on Advanced Materials and Standards", or VAMAS.
Inception
The VAMAS project was proposed by Robin Nicholson. Nicholson presented the proposal at IUVSTA meeting in Brighton, UK, in 1982, where it was well-received and subsequently led to the establishment of the VAMAS project. Nicholson and his colleagues recognised the need for international standards for the characterisation of surfaces and interfaces using X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES), and proposed the idea for a collaborative project to develop and promote such standards. The proposal was a result of a collaboration between the National Physical Laboratory and the UK Department of Trade and Industry, and it received significant support from the international scientific community.
Then, the proposal was put forward by Nicholson (Government Chief Scientist) to Prime Minister Thatcher to consider on 8 October 1982. In his letter, Nicholson outlined UK capabilities in excelling in Materials science research and development but "failed to reap the commercial rewards" VAMAS was meant to address the "entire materials cycle [which] is a fundamental component of economic production and technological innovation" (said President Regan), including the lack of agreed standards, test procedures, etc., which prevents the European Community from being taken as a single market for a new product involving the use of new materials.
On 15 October 1982, Thatcher agreed to the proposed approach, and during the early stages of the project, the Margaret Thatcher government provided significant financial and political support. Thatcher herself was reported to have taken a keen interest in its progress.
The United States expressed its intention to play an active role. The United Kingdom and the United States became the leading countries. Out of the original 18 projects, VAMAS is the only project that continues to this date.
Formation
The first VAMAS meeting was held at the National Physical Laboratory (NPL) in Teddington, London, in 1983. There, Ernest Hondros was selected as the Chair for the Steering Committee.
VAMAS founding countries are (1982-1983): Canada, France, Germany, Italy, Japan, UK, USA, and European Economic Community. Brazil, Mexico, Chinese Taipei, South Africa, Australia, South Korea, and India joined later between 2007 and 2008, and China joined in 2013. VAMAS is supported by leadership in National measurement institutes (NMI) including NPL, National Institute for Materials Science (NIMS), National Bureau of Standards (today's National Institute of Standards and Technology, NIST), The British measurement and testing association (BMTA), International Bureau of Weights and Measures (BIPM), and Federal Institute for Materials Research and Testing (BAM).
VAMAS signed a memorandum with International Organization for Standardization (ISO) in 1993, International Electrotechnical Commission (IEC) in 1995, International Bureau of Weights and Measures (BIPM) and Asia Pacific Metrology Programme (APMP) in 2020.
First VAMAS technical groups included "Wear Test Methods" led by (Germany), "Surface Chemical Analysis" led by Cedric J Powell (US), "Polymer Blends" led by Lechoslaw Utracki (Canada), and "Ceramics" led by Phillipe Boch (France).
The first round-robin test was held for Wear test methods and the results were reported in 1987.
Objectives
Using new materials is crucial in advancing technology in fields such as electronics, energy, aerospace, and biotechnology. However, these materials have different qualities compared to traditional materials, which poses a challenge in standardisation and testing methods. In order to promote their use and distribution, it is important to consider the international division of labour and future product distribution. Developing international standards for new materials effectively removes technical barriers to trade and promotes global information circulation and data sharing. Unlike conventional materials, new materials must be standardised before the production of the object is standardised, or the use of the method has been socially accumulated. Thus, standardisation for new materials is considered pre-emptive rather than follow-up.
VAMAS initiative emerges from these needs as a collaborative endeavour involving national metrology institutes, universities, research institutions, and industry, with the primary goal of promoting international cooperation and accelerating technological advancement by facilitating the exchange of information and standardising measurement methods related to advanced materials. VAMAS support pre-standards research by providing the technical basis for measurements, testing, specifications, and standards. Using interlaboratory studies, this will lead to new improved test procedures, reference materials and data, or algorithms and software with the researchers being drawn from VAMAS and non-VAMAS countries. Results of these activities are submitted to ISO, Regional or National Standards bodies.
The project has generated a wealth of technical reports that offer detailed guidance on various aspects of materials characterisation, including sample preparation, measurement conditions, data analysis, and reporting. These reports are publicly accessible and widely utilised as a reference by researchers, instrument manufacturers, and testing laboratories. In addition to its efforts to establish materials characterisation standards, the VAMAS project has also contributed to the development of international standards for other areas of materials science, such as mechanical testing, thermal analysis, powder diffraction, X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and secondary ion mass spectrometry (SIMS). Its endeavours have led to the emergence of new materials and technologies and fostered international collaboration in research and development.
More than 85 national, regional or international standards, 50 VAMAS reports, 5 ISO technology trends assessments (TTA), and 600 publications were resulted from VAMAS work.
Structure
Steering Committee
VAMAS has a Steering Committee and a Technical Working Groups, with the latter responsible for conducting research cooperation activities in each technical field and managing research projects. The majority of joint research themes adopted by the Steering Committee focus on standardising testing and evaluation techniques. The Steering Committee, which includes representatives from Member States and the European Commission, has approves the launch of several sector working parties to promote the use of advanced materials in high-technology products and encourage international trade. This can be achieved through either national experts agreeing on compatible standards or through multilateral research to establish scientific and metrological bases for standardisation.
The Steering Committee has a Chair and secretariat both from the same host institute, and they are elected every 5 years. The secretariat publishes announcements of the Technical Working Group's activities. The Steering Committee meets annually.
Technical work areas
VAMAS technical work areas (TWA) are list for active and completed.
International Interlaboratory Comparison
International Interlaboratory Comparison is a method of ensuring the accuracy and reliability of testing results by comparing the measurements made by different laboratories worldwide. In this method, a sample is sent to multiple laboratories in round-robin tests, and each laboratory measures the same sample using their respective methods and equipment. The results are then compared to identify any differences or discrepancies, and to evaluate the consistency and reliability of the methods used by each laboratory. This process helps to ensure that the testing and measurement methods used by laboratories are accurate, and that the results obtained can be trusted and used confidently.
References
Standards (metrology)
Research institutes
Materials science institutes | VAMAS | [
"Materials_science"
] | 2,214 | [
"Materials science organizations",
"Materials science institutes"
] |
51,994,997 | https://en.wikipedia.org/wiki/Yamaha%20YMZ280B | The Yamaha YMZ280B, also known as PCMD8, is a sound chip produced by Yamaha Corporation. It is an eight-channel PCM/ADPCM sample-based synthesizer designed for use with video game machines, packaged in a 64-pin QFP.
Features
Up to 8 simultaneous sounds (voices)
Waveform data lengths of 4 (ADPCM), 8, 16 bits (PCM)
Stereo output (with a 4-bit/16-level pan for each voice)
Up to 16 MB of external memory for wave data
External ROM or SRAM memory.
The YMZ280B can either use an internal crystal oscillator running at 16.9344 MHz or be connected to a master clock line. The chip can be connected to up to 16 MB of external memory to provide the voice data for sound reproduction. The sound data can be encoded as 4-bit ADPCM, 8-bit PCM, or 16-bit PCM, played back in a wide range of frequencies (up to 256 steps), and then mixed together and output as a two's complement MSB-first digital data stream meant to be connected to a complementing DAC chip like the YAC513. The YMZ280B can also be connected to a YSS225 effects processor (EP), allowing two of the 8 channels to be processed further.
Products
Per its design, the YMZ280B found significant use in arcade machines from the late 1990s. The first generation of video games from Cave were among the first to employ the chip. Later games from Data East and Kaneko also employed the chip.
References
Yamaha sound chips | Yamaha YMZ280B | [
"Technology"
] | 348 | [
"Computing stubs",
"Computer hardware stubs"
] |
51,995,554 | https://en.wikipedia.org/wiki/Active%20updating | In computer programming, suppose we have a data item A whose value depends on data item B, i.e., the value of A must be changed after the value of B changes and before the value of A becomes necessary. Active updating is updating A immediately after B changes, while passive updating or lazy updating (lazy evaluation) is updating A immediately before its value is fetched. And example of this distinction is, e.g., in the implementation of GUI applications: the list of submenu items may depend on the state of the application; this list may be updated either as soon as the state of the application changes ("active") or only when the menu is invoked ("passive").
Another example is update a visual display as soon as the underlying data change as opposed to clicking the "redraw" button. In this situation active update may create a problem to deal with: an abrupt change of some part of the display may coincide in time with the saccadic movement of the eye, and the change may go unnoticed by a human observer.
See also direct updating vs. deferred updating in transaction processing.
References
Programming idioms | Active updating | [
"Engineering"
] | 245 | [
"Software engineering",
"Software engineering stubs"
] |
51,996,919 | https://en.wikipedia.org/wiki/Pedals%20%28bear%29 | Pedals (died October 2016, New Jersey, United States) was an American black bear (Ursus americanus) that walked upright on its hind legs because of injuries on its front paws. After videos of the bear were posted on the internet, more than 300,000 people signed a petition to move the bear to a wildlife sanctuary. However, Pedals appears to have been one of hundreds of bears killed by bullets or arrows in October 2016 in New Jersey's first sanctioned bow-and-arrow hunt in four decades.
Fame
Pedals was first spotted walking upright in 2014 in Oak Ridge, New Jersey, spurring debate and discussions. Videos of Pedals' bipedal walking were posted to the internet and he was described as an "internet sensation". Officials initially warned that the videos might be a hoax.
Over 300,000 people concerned with Pedals' welfare signed a petition written by Lisa Rose Rublack to relocate the bear to the Orphaned Wildlife Center in Otisville, New York. Supporters donated $22,000 to a fund created by Sabrina Pugsley to move the bear to the sanctuary to prevent it from struggling to survive in the wild. New York officials opposed the transfer of Pedals to the sanctuary.
Pedals was being monitored by the New Jersey Department of Environmental Protection's Division of Fish and Wildlife, which asked residents to report sightings by calling a hotline and announced in 2016 that the bear had not been seen since the previous Christmas.
Death
Pedals' internet fame led Angi Metler, director of the Bear Education and Resource Group, to believe he would be targeted by bear hunters. In October 2016, reports of Pedals being killed by a hunter received widespread attention. On October 17, 2016, the New Jersey Department of Environmental Protection announced they believed Pedals had been killed during the officially sanctioned hunt. The October 10–15 hunt was New Jersey's first sanctioned bow and arrow hunt since the 1960s. During the hunt, which also permitted muzzle-loading rifles, a total of 562 bears were killed.
In response to the killing, State Senator Raymond Lesniak introduced a bill dubbed "Pedals' Law" that would ban black bear hunting in New Jersey for five years.
In December 2016, a hunter filed a defamation lawsuit in Morris County Superior Court alleging he was falsely accused on social media of being Pedals' killer, suffered death threats, and had his personal information published.
See also
List of individual bears
Bear hunting
Rare 'big tusker' elephant killed by Leon Kachelhoffer
References
External links
Video of Pedals using the bear's bipedal gait.
2014 in New Jersey
2016 animal deaths
2016 controversies in the United States
Ethology
Individual animals in the United States
Individual bears
Individual wild animals | Pedals (bear) | [
"Biology"
] | 560 | [
"Behavioural sciences",
"Ethology",
"Behavior"
] |
51,997,255 | https://en.wikipedia.org/wiki/Bangladesh%20Computer%20Council | The Bangladesh Computer Council (BCC) is a statutory government organization operating under the Information and Communication Technology Division of the Ministry of Posts, Telecommunications, and Information Technology of the government of Bangladesh. Its headquarters are situated in Agargaon, Dhaka, Bangladesh. It was initially known as the National Computer Committee (NCC) in 1983 and transformed into the Bangladesh Computer Council through Act No. 9 of the National Parliament in 1990.
Since its inception, the BCC has been an important advocate for the country's technological development, specifically in information and communications technology (ICT). In collaboration with government organizations in Bangladesh, this organization is responsible for developing national ICT plans, strategies, and policies, empowering Digital Bangladesh, implementing e-government, and collaborating with various government organizations and private sector partners. They also set ICT standards and specifications, develop ICT infrastructure, provide advice on IT technology utilization and security measures, identify issues related to national cyber security and cybercrimes, and investigate, remediate, prevent, and suppress these issues.
The BCC has undertaken numerous projects to improve the country's ICT infrastructure, such as BanglaGovNet, Info-Sarker Phases II and III, Connected Bangladesh, and others, many of which have already been completed. It has also significantly contributed to human resource development by providing training to thousands of individuals, including the disabled, transgender and third-gender communities, and women entrepreneurs.
The BCC has been organizing various competitions and events to promote information technology education in the country, including the National Children and Youth Programming Contest, the International Blockchain Olympiad, and the International Collegiate Programming Contest. These events provide opportunities for people of all ages and backgrounds to showcase their skills and passion for this field, advance the country's startup ecosystem, and increase computer programming's popularity among the younger generation. In 2022, the BCC organized the 45th Annual International Collegiate Programming Contest World Final in Dhaka, Bangladesh.
The organization has received several awards and recognitions for its achievements in promoting ICT in Bangladesh, such as the WITSA award, WSIS Winner Prize, ASOCIO Digital Government Award, Open Group President Award, Public Administration Award 2017, etc.
History
The government of Bangladesh established the National Computer Committee (NCC) in 1983. Nevertheless, the National Computer Board (NCB) took over the role of the NCC in 1988. In 1989, the "Bangladesh Computer Council Ordinance" was put into effect. The following year, the National Parliament enacted Act No. 9, "Bangladesh Computer Council Act, 1990", which transformed the National Computer Board into a statutory body under the name "Bangladesh Computer Council". BCC continued to function under the President's Secretariat until 1991. In 1991, this organization was placed under the Ministry of Science and Technology, which later became the Ministry of Science and Information and Communication Technology.
Over the years, the BCC has evolved and expanded its scope of activities to meet the growing demands of the ICT sector. In 2011, the BCC was placed under the newly created Information and Communication Technology Division of the Ministry of Posts, Telecommunications and Information Technology of the government of Bangladesh (GoB).
Objectives
The Bangladesh Computer Council operates with the following objectives to advance ICT in Bangladesh:
Setting and implementing national information technology policies, strategies, and plans for effective application and expansion of ICT in the country
Empower Digital Bangladesh.
Implement e-government.
Collaborate with the different government agencies and private sector partners to execute National ICT Plans.
Foster research and development in ICT.
Develop skilled human resources for IT-based industries.
Responsibilities
The key responsibilities of the Bangladesh Computer Council include:
Encouraging the use of ICT for social and economic development
Developing the practical infrastructure for the use of computers in various sectors of the national economy and improving the quality of education, training, and professional standards related to computers
Helping Bangladeshi citizens become competitive in the field of information technology
Developing human resources and skills in computer technology and exporting these resources to the global market
Formulating and implementing national ICT strategies and policies
Cooperating with the government and other organizations in the use of ICT and providing them with advice
Promoting the use of ICT in government and other organizations
Providing advice on security measures for the use of ICT
Building training centers, libraries, and laboratories for computer science, providing the necessary equipment, and maintaining them
Collecting, analyzing, and disseminating information on ICT
Publishing reports, projects, and periodicals on computer science and ICT
Organizing discussions and workshops on computer science, ICT, and other related topics and conducting training on these topics
Providing grants for research, education, and training in ICT
Communicating and cooperating with all relevant government, private, domestic, and foreign organizations in the interest of achieving national goals in the field of ICT
Negotiating and signing contracts with domestic and foreign organizations with the prior approval of the government as necessary for the performance of the BCC's functions
Carrying out any special duties assigned by the government related to computer science
Defining the standards and specifications of computer science and ICT
Taking any necessary steps to perform the above-mentioned functions
These responsibilities encompass a wide range of initiatives and projects aimed at contributing to the development of the ICT sector in Bangladesh.
Organizational structure
The BCC has a robust organizational structure that allows it to handle its wide range of responsibilities and initiatives efficiently. The Executive Director is the highest-ranking official and is responsible for overseeing all operations of this organization. Under the Executive Director, there are three primary Divisions, each headed by a Member, and each of these divisions further consists of several subdivisions, each overseen by a Director. The Technical Division handles technical matters such as data center operations, Certifying Authority activities, Object Identifier (OID) operations, and government-level ICT support services. The Policy, Strategy, and Development Division is responsible for formulating and overseeing information technology policies, strategies, and development efforts. The Capacity Development and Human Resources Division is in charge of capacity building and human resource functions for the ICT sector.
Regional offices
BCC has established seven regional offices in different parts of the country, which collaborate with local governments and non-governmental organizations to develop and implement national information and technology policies, strategies, and plans. These offices also assist in the implementation of e-government initiatives at the local level. Furthermore, They provide ICT training, develop ICT curricula, and support human development by hosting workshops, seminars, and online practice and e-learning activities in their respective regions with the collaboration of the local ICT industry. Regional offices of this organization:
Rajshahi office
Chattogram office
Khulna office
Sylhet office
Barishal office
Faridpur office and
Rangpur office.
BCC's Council Committee
The BCC's Council Committee is a group of 12 individuals from various government departments. The council is in charge of supervising and directing the council's operations. According to the information available, the members of the Council Committee are as follows:
Chairperson: The State Minister of the Ministry of Information and Communication Technology
Vice-Chairperson: Secretary of the Ministry of Information and Communication Technology
Member Secretary: Executive Director of Bangladesh Computer Council
Members: There are 7 members in the BCC's Council Committee.
Activities and services
CA operation and security
BCC's CA Operations and Security serves as the sole official Certifying Authority of the government of Bangladesh. Its duties entail overseeing CA operations, enforcing regulations, and managing Electronic Signatures and a secure repository of electronic signature certificates. This guarantees a reliable infrastructure for secure electronic transactions and communications in Bangladesh while providing secure digital certificates, web-based SSL certificates, PKI tools, and e-signatures to government organizations.
Network Operations Center
The National Network Operation Center (NOC) was formed in 2014 to operate and maintain the e-government Network. It focuses on network security, planning, research and development, operation, upgrade, and maintenance of nationwide government networks. NOC provides internet, intranet, extranet, and government video conference networks for the President, Prime Minister, Ministries, Bangladesh Secretariat, and field administration. NOC provides consultation with other government organizations in preparing network standards and specifications. Currently, it is providing network operation and maintenance services in 18,834 government offices up to the upazila level. It also monitors the network connectivity of 2600 unions under the national priority project named ‘Info Sarker-3’.
Data center
BCC operates a Tier III-certified National Data Center in Bangladesh that offers a comprehensive range of services to government organizations. This data center provides secure and reliable cloud services and the storage and management of digital data for various government agencies and organizations in the country.
The National Data Center offers a range of Cloud computing services, including Elastic Cloud Server (ECS), Image Management Services (IMS), Elastic Volume Service (EVS) for Cloud Storage, Volume Backup Service (VBS), and Cloud Server Backup Service (CSBS) for Cloud Backup. In addition, it provides Virtual Private Cloud (VPC), Elastic IP (EIP), Elastic Load Balancer (ELB), and Virtual Firewall (VFW) for Cloud Network Services. Other services offered are virtual Private Servers, Load Balancing, Email Service, Web Hosting, Backup, and Colocation Services. A dedicated security team is in place to monitor and handle any security incidents that may arise.
Testing, Quality Control and Certification
This wing facilitates the testing (functional, performance, and security) of all software, applications, and mobile apps developed and procured by the government entity for e-government service delivery. It also conducts hardware testing, ensures quality assurance, and coordinates software certification.
Research and development
BCC is conducting research and development work on emerging technologies in the field of information technology. It formulates appropriate standards for implementing e-governance and software and hardware for capacity development, and it works on interoperability. It establishes and manages appropriate centers or systems to develop the innovative power of potential ICT graduates. It works on the development of IT personnel according to domestic and international markets and the commercialization of ICT.
Policy, strategy, and planning
BCC assists the government of Bangladesh in policy formulation, implementation, and monitoring. This organization coordinates with government institutions, conducts studies and surveys, and develops management information systems to address national needs.
ICT-related consultancy services
BCC provides ICT-related consultancy services to government and public organizations. These services include requirements analysis for hardware and software, technical specification preparation, requirement analysis for automation, tender document preparation, and tender evaluation for government organizations with e-government empowerment initiatives. Additionally, they provide on-demand websites and software development. Furthermore, BCC offers ICT professional recruitment assistance.
Condemnation service
BCC provides a crucial condemnation service for computers and related equipment, ensuring proper identification and removal of outdated, obsolete, or non-functional hardware for all government offices in Bangladesh. This service encourages responsible electronic waste disposal and the adoption of advanced technologies.
Object identifiers
BCC is the country Registration Authority (RA) for Object identifiers (OIDs). They received approval from the International Telecommunication Union (ITU) on July 30, 2012, to function as the country's RA. As the RA, this organization is responsible for allocating and managing OIDs within the country's OID allocation structure, which starts with country OID 2.16.50. The BCC oversees OID registration, ensures compliance, approves OIDs for the global repository, collaborates with ITU-T, defines valid objects, and assists OID users. As the country's RA, this organization facilitates a secure PKI and other IT initiatives.
BGD e-GOV CIRT
The Bangladesh e-government Computer Incident Response Team, also known as the National Computer Emergency Response Team of Bangladesh, is responsible for preventing and responding to cyber security threats within the country. They work closely with international partners to ensure the safety of Bangladesh's cyberspace. Their duties include receiving reviews, responding to computer security incidents, conducting research and development, and providing guidance on security threats and vulnerabilities. Additionally, they assist government organizations, financial organizations, law enforcement agencies, academia, and civil society in improving overall cyber security. They also provide the necessary support to the 'Digital Security Agency'.
BGD e-GOV CIRT offers a range of essential services, including incident handling, digital forensics, cyber security training, threat intelligence, IT audits, cyber sensors, risk assessment, and awareness building. These services help organizations identify and respond to security incidents, evaluate potential security gaps, and build awareness about the importance of cyber security.
Bangladesh National Digital Architecture
The government of Bangladesh has developed a National Enterprise architecture framework called the Bangladesh National Digital Architecture Framework based on leading standards, practices, and frameworks like Open Group's TOGAF 9. This framework has been customized to meet the specific requirements and strategic objectives of the country.
It consists of various key components that aim to establish the Bangladesh National Enterprise Architecture Framework. Such a component is the eGovernment Interoperability Framework, which ensures seamless integration and communication across different government departments and agencies. The Mobile Service Delivery Platform defines the architecture and standards for efficient mobile service delivery. The National e-Service Bus acts as a middleware application or platform, facilitating the integration of e-services.
Training and development
BCC offers various training courses and programs, as well as job fairs, workshops, seminars, and programming competitions nationwide. They also provide specialized training and events for disadvantaged communities, including the disabled and third-gender communities. Women entrepreneurs can also access various training opportunities.
Bangladesh Korea Institute of Information and Communication Technology (BKIICT)
To satisfy the rising demand in both the national and international job markets, BCC maintains an ICT training institute called BKIICT that provides a variety of ICT-related programs, including standard certification courses, diplomas, and post-graduate diplomas. The institute also provides customized courses for government officials to improve their ICT skills and efficiency. Besides, BKIICT conducts aptitude tests for ICT candidates applying for jobs in various government departments and organizations on behalf of those institutions. They also conduct computer proficiency tests and provide lab rental services according to government requirements.
Information-Technology Engineers Examination in Bangladesh
BCC's Bangladesh ICT-Engineers Examination Center, known as BD ITech, is responsible for the annual administration of the Information Technology Engineers Examination (ITEE) in Bangladesh. The ITEE is an internationally recognized information technology examination developed by Japan's Information Technology Promotion Agency (IPA). This exam applies to both IT and non-IT professionals and graduates, and their knowledge and skills in this field can get international recognition. Since 2013, BD-iTech has been entrusted by the Japanese government to conduct, implement, and certify ITEE exams in Bangladesh.
Projects
BCC is conducting various national-level projects to improve the country's ICT infrastructure. Some such projects are:
Contributions
Human resource development
The BCC has made significant contributions to ICT human resource development. The BCC and its various projects have trained over 2,36,000 individuals, including 187,200 males and 46,800 females, in various ICT skills until April 3, 2023. Notably, from 2010 to 2022, BKIICT and 7 regional centers trained 36,000 individuals in diploma/PGD and short-term courses, preparing them for global employment opportunities. BCC has also empowered teachers and students, with 7,890 teachers trained as master trainers and 112,189 students receiving Basic ICT training.
The council has provided training in emerging technologies like artificial intelligence (AI), the internet of things (IoT), blockchain, robotics, big data, medical scribe, and cyber security to government employees, educational institution teachers, entrepreneurs, and IT professionals. BCC has partnered with esteemed organizations such as Coursera, Facebook, and the National University of Singapore to enrich the training landscape in the country. Moreover, this organization has set up an assessment and certification platform to foster skilled manpower development and further fuel the growth of the IT industry in Bangladesh.
Infrastructure development
The Bangladesh Computer Council has been actively involved in the development of ICT infrastructure in Bangladesh to realize the Digital Bangladesh vision. Their projects have been instrumental in the implementation of Digital Bangladesh. One of their most significant contributions is the expansion of the ICT Tower (formally known as the BCC Tower) to accommodate various important institutions related to ICT. The building has been transformed into a "Center of Excellence" for all ICT-related government work.
The organization established Union Information and Service Centers (UISCs) through solar power in various unions without electricity, which were later renamed Union Digital Centers (UDCs). They have also established Digital Centers like UISC at various offices in different upazilas across the country. This organization has set up computer labs and smart classrooms in different educational institutions. They have also established cybercenters at various universities and colleges.
Moreover, BCC has set up the National Data Center (Tier III), providing uninterrupted services to various government offices. The Disaster Recovery Center located in Jessore has been established, along with the 7th largest National Data Center (Tier-IV) Center in the world at Bangabandhu Hi-Tech City, Kaliakair, Gazpur.
BCC has established a nationwide government network connectivity backbone under different projects, providing high-speed internet connections through optical fiber cable and the latest technology in video conferencing in several government offices across the country. Apart from this, the organization has set up Agricultural Information and Communication Centers and Telemedicine Centers. They have also established WiFi networks in the Bangladesh Secretariat and ICT Tower and virtual private network (VPN) connectivity in the Bangladesh Police. At present, the process of providing connectivity to the unions in remote areas is underway under the Connected Bangladesh project. BCC has connected India, Nepal, Bhutan, and Bangladesh by optical fiber cable to increase data exchange capacity. This organization has set up a 50-meter-high self-supported tower under the project entitled ‘Digital Island Moheskhali’ to introduce high-speed internet service. They have also set up an IP camera-based surveillance system to make Sylhet a "Safe City" under the "Digital Sylhet City" project.
BCC has an idea fab lab, a specialized network lab, a software and hardware quality testing lab, a digital forensic lab, a cyber range, and a cyber defense training center. These labs are facilitated with world-class, advanced devices and technology. In addition, this organization has deployed cyber-sensor technology on various critical information infrastructures.
Standards development
As information technology continues to advance, it is crucial to establish standards that can enhance the accessibility of the Bengali language in the field of information technology, ensuring its ease of use for everyone. The responsibility of promulgating these standards lies with the Bangladesh Standards and Testing Institution (BSTI), while the task of technical drafting and declaration is carried out by the BCC. The organization has already developed several standards and simultaneously modernized the existing ones. Bangladesh Standards are:
Bangladesh Standard Specification for Bangla Coded Character Set for Information Interchange (Third Revision) (BDS 1520:2018): It defines the character encoding scheme for the Bangla script, facilitating information exchange and compatibility across various computer systems and applications in Bangladesh. This specification ensures seamless communication and data sharing, promotes the development of localized software and content in the Bengali language, and ultimately enhances accessibility and inclusivity for the Bengali-speaking population in the digital realm.
Bangladesh Standard Specification for Computer Bangla Keyboard (First Revision) (BDS 1738:2018): This standard outlines the standardized requirements for keyboards specifically designed to input the Bengali script into computer systems. Introduced in 2018, this standard ensures uniformity and compatibility among computer Bengali keyboards, facilitating efficient and accurate typing of Bengali characters. BDS 1738 defines the layout, key arrangement, and functional characteristics of the keyboard, ensuring it meets the needs and preferences of Bangla language users in Bangladesh.
Bangladesh Standard Codes for Information Interchange (BDS 1934:2018): To ensure compatibility and consistency in data exchange across various computer systems and applications within the country, there is a need for a national standard for ASCII-based Bengali character and symbol coding. The Bangladesh Computer Council has addressed this need by drafting the Bangladesh Standard Code for Information Interchange (BSCII). This code was created by reviewing popular Bengali language software based on ASCII in Bangladesh, and it includes a total of 210 Bengali letters, symbols, and compound letters. Its purpose is to define the character encoding system used for the interchange of information.
Due to lack of coherence and synergy between vendors and technologists, these standards were largely never widely accepted nor recognized by international bodies. Later, versions of standards such as BSCII in essence rubber stamped Unicode encoding scheme.
An official order to mandatorily install a keyboard layout package kit in 2018 spawned furor over multiple fronts.
Notable events
National Children and Youth Programming Contest 2018
The BCC organized the 'National Children and Youth Programming Contest 2018' to nurture the interest of children and adolescents in information technology education. Students from different schools across the nation participated in this competition, which concluded with an award ceremony at the BCC auditorium on .
National Collegiate Programming Competition (NCPC) 2020
On February 22, 2020, the National Collegiate Programming Competition (NCPC) organized by the BCC was held at the Military Institute of Science and Technology (MIST) in Dhaka, Bangladesh. Teams from different public and private universities took part in the event.
National ICT Competition 2020 for Persons with Disabilities
The BCC held the National ICT Competition for Youth with Disabilities on November 21, 2020, with different contestants from various regions. The competition was held at regional offices, including the head office in Dhaka.
iDEATHON
The BCC and South Korea organized the 'iDEATHON' contest to promote startup entrepreneurs in Bangladesh in 2020. The top 5 startups were awarded prestigious titles, and 10 entrepreneurs from the winning startups received a 6-month training program in South Korea, enhancing their expertise and capabilities. The competition aimed to advance the country's startup ecosystem.
Bangabandhu Innovation Grant 2021
The iDEA project under the BCC organized the 'Bangabandhu Innovation Grant-2021' to encourage young entrepreneurs and startups in honor of the Golden Jubilee of Independence and Mujib Year. Startups and innovators from different countries, including Bangladesh, participated in the event. The winning startup is awarded a grant of USD 100,000.
Sheikh Russel Day 2021
On the auspicious occasion of 'Sheikh Russell Day 2021,' the Prime Minister Sheikh Hasina inaugurated a distribution program for 600 laptops to 600 disabled persons trained in ICT by the "Empowerment of Persons with Disabilities (PWD) including NDD through ICT" project under the BCC.
Bangladesh Robot Olympiad 2021
The fourth Bangladesh Robot Olympiad 2021 was organized in collaboration with the Information and Communication Technology Division, Dhaka University’s Department of Robotics and Mechanical Engineering, the Bangladesh Open Source Network, and the Bangladesh Computer Council.
International Blockchain Olympiad 2021
The International Blockchain Olympiad (IBCOL) 2021, organized by the ICT Division of Bangladesh, Bangladesh Computer Council, Blockchain Olympiad Bangladesh, and Technohaven Company Limited, took place in Dhaka, Bangladesh, on October 8–10, 2021, coinciding with Bangladesh's Golden Jubilee of Independence.
Global IT Challenge 2021 for Youth with Disabilities
Despite the challenges posed by the COVID-19 pandemic, Bangladesh actively participated in the Global IT Challenge 2021 for Youth with Disabilities. The event, held online from South Korea, witnessed outstanding performances from four contestants representing Bangladesh, who were recognized with four prizes, including the esteemed Best Award (1st place).
Artificial Intelligence for Bangla’ Competition 2021
The Artificial Intelligence for Bangla’ Competition 2021 aimed to encourage university students, researchers, and developers to explore the Bengali language and technology. The competition sparked enthusiasm and increased interest in working with Bengali language-related AI and information technology.
National High School Programming Competition 2021
The National High School Programming Competition (NHSPC), organized by the BCC in 2021, encourages 6th–12th grade students in high schools, colleges, and madrasas to explore computer programming. The aim is to increase computer programming's popularity among young students.
National Girls Programming Competition (NGPC) 2021
The 5th National Girls Programming Competition 2021 is jointly organized by the ICT Division, the Bangladesh Computer Council, and the Department of Computer Science and Engineering at Daffodil International University. Female students from various universities across the country participated in this competition.
45th Annual International Collegiate Programming Contest World Finals
The 45th Annual International Collegiate Programming Contest World Finals took place in Dhaka, Bangladesh, from November 6 to November 11, 2022. The event was organized in partnership with the ICT Division of Bangladesh, the ICPC Foundation, the Bangladesh Computer Council, and the University of Asia Pacific.
National High School Programming Contest 2022
To motivate the students more in ICT and programming and to help them test their programming skills at a national level, the ICT Division of Bangladesh and Bangladesh Computer Council are jointly organizing the National High School Programming Contest 2022 with the slogan ‘জানুক সবাই দেখাও তুমি’.
Awards
WITSA award
The Innovation Design and Entrepreneurship Academy (iDEA) Project of the BCC was runner-up in the Public-Private Partnership (PPP) category of the 2020 WITSA Global ICT Excellence Awards.
WSIS Winner Prize 2020
In 2020, the e-recruitment platform of BCC received this award under the e-Employment category at the 9th annual WSIS Winner Prizes for Recruitment Process Management as a Shared Service for Government Agencies of Bangladesh.
WSIS Winner Prizes 2019
In 2019, BCC won the WSIS Winner Prizes for the Establishment of Bangladesh National Digital Architecture (BNDA) and e-government Interoperability Framework (e-GIF).
WSIS Champion Prize 2019
In 2019, BCC received the WSIS Champion Prize for the Development of National ICT Infra-Network for Bangladesh Government (Info-Sarker) Project.
ASOCIO 2018 Digital Government Award
The Info-Sarker Phase 3 project of the BCC has been recognized with the esteemed ICT sector award ASOCIO 2018 Digital Government Award by the Asian-Oceanian Computing Industry Organization (ASOCIO).
E-Asia 2017 Award
During the Asia Pacific Council for Trade Facilitation and Electronic Business Summit 2017, the BCC's Info-Sarker Phase 3 initiative also won the E-Asia 2017 Award.
DCD APAC Award 2019
The 4-Tier National Data Center (4TDC) Project of the BCC was awarded the DCD APAC Award 2019 in the Data Center Construction Category.
Open Group President Awards 2018
The Bangladesh Computer Council received the 'Open Group President Awards 2018' in the category of innovation for their work in developing the Bangladesh National Enterprise Architecture (BNEA) and e-government Interoperability Framework (e-GIF). This achievement was recognized for its contribution to making government information and services interoperable, ultimately supporting the goal of establishing a "Digital Bangladesh" by the year 2021.
Open Group President Awards 2019
The Bangladesh Computer Council has been awarded "The Open Group President's Award" in the category of "Architecture Enabled Government Transformation" for the e-recruitment system in 2019.
Public Administration Award 2017
The Hon'ble Prime Minister presented the Public Administration Award 2017 to the Bangladesh Computer Council in recognition of their significant contribution to public service.
References
Posts, Telecommunications and Information Technology|Information and Communication Technology Division
Government agencies of Bangladesh
Organisations based in Dhaka
Information technology in Bangladesh
Information technology
Standards organisations in Bangladesh
Bengali-language computing | Bangladesh Computer Council | [
"Technology"
] | 5,609 | [
"Information and communications technology",
"Information technology"
] |
51,997,781 | https://en.wikipedia.org/wiki/NGC%20274 | NGC 274 is a lenticular galaxy in the constellation Cetus. It is a pair of galaxies, the other being NGC 275, which it is currently interacting with. It was discovered on September 10, 1785 by William Herschel. It is roughly 120 million light-years away.
References
External links
Type II supernova 2018cdc in NGC 274
140
0274
17850910
Cetus
Lenticular galaxies
Interacting galaxies
002980
Discoveries by William Herschel | NGC 274 | [
"Astronomy"
] | 94 | [
"Cetus",
"Constellations"
] |
51,997,795 | https://en.wikipedia.org/wiki/NGC%20275 | NGC 275 is a barred spiral galaxy located approximately 63 million light-years from the Solar System in the constellation Cetus. It is one of a pair of galaxies, the other being NGC 274. It was discovered on October 9, 1828, by John Herschel.
The galaxy was described as "very faint, small, round, southeastern of 2" by John Dreyer in the New General Catalogue, with the other of the two galaxies being NGC 274.
See also
Spiral galaxy
List of NGC objects (1–1000)
References
External links
SEDS
0275
18281009
Cetus
Barred spiral galaxies
Interacting galaxies
Discoveries by John Herschel
002984 | NGC 275 | [
"Astronomy"
] | 132 | [
"Cetus",
"Constellations"
] |
51,997,860 | https://en.wikipedia.org/wiki/NGC%20276 | NGC 276 is a barred spiral galaxy located approximately 626 million light-years from the Solar System in the constellation Cetus. It was discovered in 1886 by Frank Muller and was later also observed by DeLisle Stewart.
John Dreyer, creator of the New General Catalogue describes the object as "extremely faint, pretty small, extended 265°, 11 magnitude star 3 arcmin to north". The galaxy's right ascension was later corrected in the Index Catalogue using the observation data by Stewart.
See also
List of NGC objects (1–1000)
Pisces (constellation)
References
External links
SEDS
0276
03054
Barred spiral galaxies
?
Cetus
Discoveries by Frank Muller (astronomer) | NGC 276 | [
"Astronomy"
] | 142 | [
"Cetus",
"Constellations"
] |
51,998,268 | https://en.wikipedia.org/wiki/NGC%20277 | NGC 277 is a lenticular galaxy located in the constellation Cetus. It was discovered on October 8, 1864, by the German astronomer Heinrich Louis d'Arrest. The galaxy is situated near the celestial equator, making it observable from both the Northern and Southern Hemispheres at various times of the year. With an apparent B magnitude of 13, NGC 277 requires a telescope with an aperture of at least 10 inches (250 mm) for proper observation.
As a lenticular galaxy, NGC 277 exhibits characteristics between those of elliptical and spiral galaxies, featuring a prominent central bulge and a disk-like structure but lacking significant spiral arm features. Its precise distance from Earth is not well-documented in readily available sources, which is common for many galaxies cataloged in the 19th century. The galaxy's position and brightness make it a subject of interest for amateur astronomers equipped with sufficiently powerful telescopes.
For those interested in observing NGC 277, it is recommended to consult star charts and plan observations during times when Cetus is prominently positioned in the night sky, typically during the months of October through December. Due to its faintness, observing from a location with minimal light pollution will enhance visibility.
References
External links
0277
18641008
Cetus
Lenticular galaxies
Discoveries by Heinrich Louis d'Arrest
002995 | NGC 277 | [
"Astronomy"
] | 262 | [
"Cetus",
"Constellations"
] |
51,998,538 | https://en.wikipedia.org/wiki/Hygrocybe%20umbilicata | Hygrocybe umbilicata is a species of the fungal family Hygrophoraceae. This species is the first of its genus reported for Bangladesh. It was found in Singra Forest, Birganj, Dinajpur district of Bangladesh.
References
Fungi of Bangladesh
umbilicata
Fungi described in 2016
Fungus species | Hygrocybe umbilicata | [
"Biology"
] | 71 | [
"Fungi",
"Fungus species"
] |
51,999,333 | https://en.wikipedia.org/wiki/NGC%20279 | NGC 279 is a lenticular galaxy in the constellation Cetus. It was discovered on October 1, 1785 by William Herschel.
References
External links
0279
00532
+00-03-019a
03055
17851001
Cetus
Lenticular galaxies
Discoveries by William Herschel
Markarian galaxies | NGC 279 | [
"Astronomy"
] | 64 | [
"Cetus",
"Constellations"
] |
51,999,371 | https://en.wikipedia.org/wiki/NGC%20280 | NGC 280 is a spiral galaxy in the constellation Andromeda. It was discovered on December 5, 1785 by William Herschel.
References
External links
0280
Andromeda (constellation)
17851205
Spiral galaxies
Discoveries by William Herschel
003076 | NGC 280 | [
"Astronomy"
] | 54 | [
"Andromeda (constellation)",
"Constellations"
] |
52,000,501 | https://en.wikipedia.org/wiki/Inexact%20differential%20equation | An inexact differential equation is a differential equation of the form (see also: inexact differential)
The solution to such equations came with the invention of the integrating factor by Leonhard Euler in 1739.
Solution method
In order to solve the equation, we need to transform it into an exact differential equation. In order to do that, we need to find an integrating factor to multiply the equation by. We'll start with the equation itself. , so we get . We will require to satisfy . We get
After simplifying we get
Since this is a partial differential equation, it is mostly extremely hard to solve, however in some cases we will get either or , in which case we only need to find with a first-order linear differential equation or a separable differential equation, and as such either
or
References
Further reading
External links
A solution for an inexact differential equation from Stack Exchange
a guide for non-partial inexact differential equations at SOS math
Equations
Ordinary differential equations
Differential calculus
Discrete mathematics
Mathematical structures | Inexact differential equation | [
"Mathematics"
] | 209 | [
"Discrete mathematics",
"Mathematical structures",
"Calculus",
"Mathematical objects",
"Equations",
"Differential calculus"
] |
52,001,960 | https://en.wikipedia.org/wiki/Contact%20guidance | Contact guidance refers to a phenomenon for which the orientation of cells and stress fibers is influenced by geometrical patterns such as nano/microgrooves on substrates, or collagen fibers in gels and soft tissues. This phenomenon was discovered in 1912, and the terminology was introduced in 1945, but it is with the development of tissue engineering that researchers drew increasing attention on this topic, seeing the potential of contact guidance in influencing the morphology and organization of cells. Nevertheless, the biological processes underlying contact guidance are still unclear.
Contact guidance on two-dimensional substrates
When cells are seeded onto flat substrates, they are normally in a random orientation. However, substrates with topographical patterns influence the orientation of cells cultured on these surfaces by their geometrical cues. For example, if a substrate has nano/microgrooves running parallel to each other, cells orient along the direction of these nano/microgrooves. Based on this, cells seem to be able to sense the structural characteristics of their surrounding and consequently respond by adopting the orientation of topographical stimuli. A similar effect can be obtained when cells are cultured on flat surfaces with lines of proteins printed on top (to which cells can adhere), interspersed by repellent lines; in that case, cells also align along the patterns.
It has also been observed that the phenomenon of contact guidance on microgrooved surfaces is influenced by the groove width. For instance, osteoblast-like cells align along the nanogrooves only for grooves wider than 75 nm. A similar behavior has been observed with other cell types, such as fibroblasts, which align along these topographical patterns when the grooves are wider than 150 nm. On the other hand, grooves that are too wide can decrease the effects of contact guidance
Contact guidance in three-dimensional structures
Cells can orient in response to contact guidance when located inside three-dimensional structures, such as collagen gels, scaffolds, and soft tissues. In those conditions, the geometrical cues provided by collagen or scaffold fibers are able to influence the orientation of cells. For example, it has been observed that endothelial colony forming cells align along the direction of the fibers present in electrospun scaffolds. Similarly, the collagen fibers present in collagen gels and soft tissues can influence cell alignment, providing the most important stimulus in terms of cell orientation
Potential of contact guidance for tissue engineering
Recent research has highlighted the importance of cellular alignment for the mechanical properties and functionality of the prostheses developed using the principles of tissue engineering. Currently, scientists are investigating the mechanisms and potential of contact guidance to control cellular alignment, which would ultimately lead to the control of their cellular forces and certain aspects of collagen remodeling.
Biological mechanisms determining contact guidance
Many researchers have formulated hypotheses on the biological mechanisms determining contact guidance. In general, cellular contraction, stress fibers and focal adhesions seem to play an important role. Recently, a computational model has been developed that is able to simulate the re-alignment of cells and stress fibers on top of grooved surfaces. Briefly, it has been supposed that cells, once seeded, form focal adhesions on top of the ridges and not above the grooves.
Once formed, the focal adhesions produce a signal that starts to diffuse into the cell inducing stress fiber assembly. At this point, there are two different possibilities, depending on the groove size. On the one hand, when the groove size is small, the intracellular signal produced by focal adhesions on the ridges can homogenously reach all locations in the cell. In that case, the stress fiber assembly is isotropic, and these fibers can pull on their surroundings in an isotropic fashion, and consequently the resulting cell shape is isotropic (without a preferred alignment).
On the other hand, when the groove size is relatively large, the intracellular signal cannot reach the locations of the cell situated on top of the grooves, as diffusion is limited. As a result, stress fibers form only close to the ridges, and these acto-myosin bundles pull on their surroundings anisotropically. Due to the anisotropic cellular contraction, stress fibers and cells align along the direction of the microgrooves. Further experiments are necessary to validate this theory.
References
Cell biology
Cells
Fibers | Contact guidance | [
"Biology"
] | 893 | [
"Cell biology"
] |
52,002,298 | https://en.wikipedia.org/wiki/National%20Centre%20for%20Biotechnology%20Education | The National Centre for Biotechnology Education (NCBE) is a national resource centre at the University of Reading to teach pre-university biotechnology in schools in the UK. It was founded in 1990.
History
It began as the National Centre for School Biotechnology (NCSB) in 1985 in the Department of Microbiology. It became the NCBE in 1990. For many years it was the only centre in Europe that was devoted to the teaching of biotechnology in schools. The Dolan DNA Learning Center had been set up in the USA.
It was set up as an education project by the Society for General Microbiology, now the Microbiology Society. Money from the Laboratory of the Government Chemist set up the National Centre for School Biotechnology (NCSB). Money also came from the Gatsby Charitable Foundation. For the first five years, the UK government's DTI was involved, but from 1990 onwards wanted the organization to become self-supporting as it had to cut back on budgets. By 1992 the government provided no money for the centre.
Structure
The site was set up in former buildings of the University of Reading's Department of Microbiology. In 2001, the NCBE moved to new purpose-built premises in the University’s School of Food Biosciences, however the creation of a new School of Pharmacy at the University forced the NCBE to move to new premises elsewhere on the campus in 2005.
Function
It reaches out to schools to give up-to-date information on biotechnology. Biotechnology is a rapidly evolving subject, and schools cannot keep up-to-date with all that they would be required to know. It produces educational resources. It runs the Microbiology in Schools Advisory Committee (MISAC).
See also
Centre for Industry Education Collaboration at York
National Centre for Excellence in the Teaching of Mathematics, University of York
Science and Plants for Schools, another well-known science resource for UK schools
References
External links
NCBE
DNA to Darwin
Education resources from the University of Leicester
European Initiative for Biotechnology Education
1985 establishments in the United Kingdom
Biology education in the United Kingdom
Biotechnology in the United Kingdom
Biotechnology organizations
Educational institutions established in 1985
Genetics education
Science education in the United Kingdom
Scientific organizations established in 1985
University of Reading | National Centre for Biotechnology Education | [
"Engineering",
"Biology"
] | 442 | [
"Biotechnology organizations",
"Biotechnology in the United Kingdom",
"Biotechnology by country"
] |
52,002,555 | https://en.wikipedia.org/wiki/Infraorbital%20vein | The infraorbital vein is a vein that drains structures of the floor of the orbit. It arises on the face and passes backwards through the orbit alongside infraorbital artery and nerve, exiting the orbit through the inferior orbital fissure to drain into the pterygoid venous plexus.
Anatomy
Origin
The infraorbital vein arises on the face by the union of several tributaries.
Course and relations
Accompanied by the infraorbital artery and the infraorbital nerve, it passes posteriorly through the infraorbital foramen, infraorbital canal, and infraorbital groove. It exits the orbit through the inferior orbital fissure to drain into the pterygoid venous plexus.
Distribution
The infraorbital vein drains structures of the floor of the orbit; receives tributaries from structures that lie close to the floor of the orbit.
Anastomoses
The infraorbital vein communicates with the inferior ophthalmic vein. It may sometimes additionally also communicate with the facial vein on the face.
References
Anatomy | Infraorbital vein | [
"Biology"
] | 229 | [
"Anatomy"
] |
52,002,639 | https://en.wikipedia.org/wiki/NGC%206426 | NGC 6426 is a globular cluster of stars located in the equatorial constellation of Ophiuchus. It was discovered by the German-English astronomer William Herschel on 3 June 1786. This cluster is at a distance of 67,000 light years from the Sun. It has an apparent visual magnitude of 10.9 and an angular diameter of , making it difficult to observe with a small telescope.
This cluster is orbiting in the outer galactic halo at a distance of from the Galactic Core. It is one of the oldest and most metal-poor clusters in the Milky Way system. NGC 6426 has an angular half-light radius of and a tidal radius of , with a Shapley–Sawyer Concentration Class of IX. It is an estimated billion years old. Chemical abundances of four members at the tip of the red giant branch suggests there may have been at least two generations of stars, with the older stars enriching a younger generation with elements including Mg, Si, and Zn. There is also some indication of hypernova enrichment of the pre-cluster medium by lighter alpha process elements.
Based on the spectra of a dozen identified RR Lyrae variables, this is classified as an Oosterhoff type II cluster. In 2012, a carbon star was discovered near the center of the cluster.
References
External links
Ophiuchus
6426
Globular clusters | NGC 6426 | [
"Astronomy"
] | 279 | [
"Ophiuchus",
"Constellations"
] |
52,002,890 | https://en.wikipedia.org/wiki/Marie-Antoinette%20Tonnelat | Marie-Antoinette Tonnelat (née Baudot) (March 5, 1912 – December 3, 1980) was a French theoretical physicist. Her physics research focused on relativistic quantum mechanics under the influence of gravity. Along with the help of Albert Einstein and Erwin Schrödinger, she attempted to propose one of the first unified field theories. She is also known for her work on the history of special and general relativity.
Life
Early years and education
Marie-Antoinette Baudot was born on March 5, 1912, in Charolles, a commune in the Southern Burgundy region of France. She began her education at Lycée de Chalon-sur-Saône and finished her higher education at Lycée Louis-le-Grand. Initially, she pursued engineering, but she eventually obtained two degrees in the sciences and in philosophy at the University of Sorbonne in Paris.
In 1935, Tonnelat pursued a doctorate in theoretical physics under Louis de Broglie at the Institut Henri Poincaré. In 1941, she finished her doctoral thesis titled On the Theory of the Photon in a Riemannian space. The same year she got married with Jacques Tonnelat, and in 1945 went on to become a researcher at the French National Center for Scientific Research (CNRS).
Research with de Broglie
Her research focused on the field of relativistic spin-particles under the influence of a gravitational field. With de Broglie's neutrino theory of light, Tonnelat arrived at particles with maximal spin 2 from massive spin 1 particles, or photons. Spin 2 corresponded to the graviton. With her knowledge of the Klein-Gordon equation, Maxwell's equations, and the linearized version of the equation for Einstein spaces, she examined the theory for a particle with spin 2 and called it "a unitary formalism". She published a paper in the early 1940s in which she established the standard commutation relations for the quantized spin-2 field. De Broglie supported her research in unified field theory, but he himself stayed away from it and chose not to be directly involved with her studies.
Although her papers were eventually published at the French Academy of Sciences, her work was subject to delays due to an interruption caused by German occupation of France in the early 1940s.
Professional career
Tonnelat spent much of her career as an educator. After the war, Tonnelat spent some time at the Dublin Institute for Advanced Studies with scientist Erwin Schrödinger in order to focus on furthering the research she had done under de Broglie earlier in her life. Once again, she began to examine the concept of unitary formalism that comes from emerging spin-2 particles. Her time with Schrödinger inspired her interest in the relativity theory and sparked her correspondence with Albert Einstein as well. Her goal was to create one unified theory using the concepts and ideas discovered by Einstein and Schrödinger.
In 1953, just prior to Einstein's death, Marie-Antoinette Tonnelat was invited to Princeton University to speak about the topic at the International Congress for the History of Science in Jerusalem. She gave many lectures throughout her career about her work related to the theory of relativity.
In 1956, she became a chair professor of physical theories at the Faculty of Science at the University of Paris. In parallel, she taught at the Institute of History of Science and Technology (directed by Gaston Bachelard) for twenty years.
In 1965, she published a second book on unified field theories that focused on the development of research in the field. There was only one chapter in the work that referred to her own research relating to Einstein and Schrödinger, but the book contained a few references to the doctoral theses that she had advised. Tonnelat's work was mainly concerned with establishing a connection between classic and quantum field theory. She debuts an alternative theory of gravitation (linear gravity), which she had studied in 1960.
In the 1960s, Tonnelat participated as nominator for the Nobel Prize in Physics, she proposed Louis Néel in 1960 and Alfred Kastler in 1965.
In 1980, Marie-Antoinette Tonnelat's deteriorating health made it difficult for her to continue giving her lectures. She died shortly after her last lecture.
She left an unpublished work about the history of theories of light and color.
Honors and awards
Tonnelat became a Peccot Lecturer and Laureate of the Collège de France in 1943. Her talk titled "Unitary theories of light and gravitation" (). From the French Academy of Sciences she received the Pierson–Perrin Prize (1946) and the Henri Poincaré Award (1971).
For her book History of the Principle of Relativity () Tonnelat received the of the Académie Française in 1972 awarded for outstanding publications.
Tonnelat was elected member of the International Academy of the History of Science in 1973.
References
1912 births
1980 deaths
French physicists
French theoretical physicists
Quantum physicists
French women scientists
French women physicists
20th-century French scientists
20th-century French women | Marie-Antoinette Tonnelat | [
"Physics"
] | 1,032 | [
"Quantum physicists",
"Quantum mechanics"
] |
52,005,227 | https://en.wikipedia.org/wiki/C24H30O6 | {{DISPLAYTITLE:C24H30O6}}
The molecular formula C24H30O6 may refer to:
Eplerenone, a steroidal antimineralocorticoid of the spirolactone group
Estriol triacetate, an estrogen medication and an estrogen ester | C24H30O6 | [
"Chemistry"
] | 70 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
52,005,845 | https://en.wikipedia.org/wiki/Petrolingual%20ligament | The petrolingual ligament lies at the posteroinferior aspect of the lateral wall of the cavernous sinus and marks the point at which the internal carotid artery enters the cavernous sinus.
Anatomically, the petrolingual ligament demarcates two of the segments of the internal carotid artery:
The petrolingual ligament marks the end of the petrous section of the internal carotid artery.
The cavernous section of the internal carotid artery begins at the superior aspect of the petrolingual ligament.
For surgeons and radiologists, it is important to be oriented to the location of this ligament in cases of possible dissection of the internal carotid artery, as it helps determine whether the dissection has occurred inside or outside the cavernous sinus.
References
Anatomy | Petrolingual ligament | [
"Biology"
] | 167 | [
"Anatomy"
] |
52,007,407 | https://en.wikipedia.org/wiki/Infected%20cell%20protein%2034.5 | Infected cell protein 34.5 (ICP-34.5, ICP34.5) is a protein expressed by the γ34.5 gene in viruses such as herpes simplex virus; it blocks a cellular stress response to viral infection. It shares the C-terminal regulatory domain () with protein phosphatase 1 subunit 15A/B.
When a cell is infected with a virus, protein kinase R is activated by the virus' double-stranded DNA,. Protein kinase R then phosphorylates a protein called eukaryotic initiation factor-2A (eIF-2A), which inactivates eIF-2A. EIF-2A is required for translation so by shutting down eIF-2A, the cell prevents the virus from hijacking its own protein-making machinery. Viruses in turn evolved ICP34.5 to defeat the defense; it activates protein phosphatase-1A which dephosphorylates eIF-2A, allowing translation to occur again. A herpesvirus lacking the γ34.5 gene will not be able to replicate in normal cells because it cannot make proteins.
The ICP34.5 deletion is useful for the construction of oncolytic herpes viruses, as cancer cells do not restrict replication as strongly.
See also
Viral nonstructural protein
References
Viral nonstructural proteins | Infected cell protein 34.5 | [
"Biology"
] | 287 | [
"Virus stubs",
"Viruses"
] |
52,007,903 | https://en.wikipedia.org/wiki/NGC%20282 | NGC 282 is an elliptical galaxy in the constellation Pisces. It was discovered on October 13, 1879 by Édouard Stephan.
References
External links
0282
18791013
Pisces (constellation)
Elliptical galaxies
Discoveries by Édouard Stephan
+05-03-015
003090 | NGC 282 | [
"Astronomy"
] | 58 | [
"Pisces (constellation)",
"Constellations"
] |
52,007,918 | https://en.wikipedia.org/wiki/NGC%20283 | NGC 283 is a spiral galaxy in the constellation Cetus. It was discovered on October 2, 1886, by Francis Leavenworth.
References
External links
0283
18861002
Cetus
Spiral galaxies
Discoveries by Francis Leavenworth
-02-03-031
3124 | NGC 283 | [
"Astronomy"
] | 57 | [
"Cetus",
"Constellations"
] |
52,007,927 | https://en.wikipedia.org/wiki/NGC%20284 | NGC 284 is an elliptical galaxy in the constellation Cetus. It was discovered on October 2, 1886, by Francis Leavenworth.
References
External links
0284
18861002
Cetus
Discoveries by Francis Leavenworth
Elliptical galaxies
-02-03-032
3131
2MASS objects | NGC 284 | [
"Astronomy"
] | 61 | [
"Cetus",
"Constellations"
] |
52,007,945 | https://en.wikipedia.org/wiki/NGC%20285 | NGC 285 is a lenticular galaxy in the constellation Cetus. It was discovered on October 2, 1886, by Francis Leavenworth.
References
External links
0285
18861002
Cetus
Lenticular galaxies
Discoveries by Francis Leavenworth
003141 | NGC 285 | [
"Astronomy"
] | 52 | [
"Cetus",
"Constellations"
] |
52,007,956 | https://en.wikipedia.org/wiki/NGC%20286 | NGC 286 is a lenticular galaxy in the constellation Cetus. It was discovered on October 2, 1886 by Francis Leavenworth.
References
External links
0286
18861002
Cetus
Lenticular galaxies
Discoveries by Francis Leavenworth
003142 | NGC 286 | [
"Astronomy"
] | 51 | [
"Cetus",
"Constellations"
] |
52,007,985 | https://en.wikipedia.org/wiki/NGC%20287 | NGC 287 is a lenticular galaxy in the constellation Pisces. It was discovered on November 22, 1827, by John Herschel.
References
External links
0287
18271122
Pisces (constellation)
Lenticular galaxies
Discoveries by John Herschel
003145 | NGC 287 | [
"Astronomy"
] | 56 | [
"Pisces (constellation)",
"Constellations"
] |
52,008,040 | https://en.wikipedia.org/wiki/Ecosphere%20%28planetary%29 | An ecosphere is a planetary contained ecological system. In this global ecosystem, the various forms of energy and matter that constitute a given planet interact on a continual basis. The forces of the four Fundamental interactions cause the various forms of matter to settle into identifiable layers. These layers are referred to as component spheres with the type and extent of each component sphere varying significantly from one particular ecosphere to another. Component spheres that represent a significant portion of an ecosphere are referred to as a primary component spheres. For instance, Earth's ecosphere consists of five primary component spheres which are the Geosphere, Hydrosphere, Biosphere, Atmosphere, and Magnetosphere.
Types of component spheres
Geosphere
The layer of an ecosphere that exists at a Terrestrial planet's Center of mass and which extends radially outward until ending in a solid and spherical layer known as the Crust (geology).
This includes rocks and minerals that are present on the Earth as well as parts of soil and skeletal remains of animals that have become fossilized over the years. This is all about process how rocks metamorphosize. They go through solids to weathered to washing away and back to being buried and resurrected. The primary agent driving these processes is the movement of Earth’s tectonic plates, which creates mountains, volcanoes, and ocean basins. The inner core of the Earth contains liquid iron, which is an important factor in the geosphere as well as the magnetosphere.
Hydrosphere
The total mass of water, regardless of phase (e.g. liquid, solid, gas), that exists within an ecosphere. It's possible for the hydrosphere to be highly distributed throughout other component spheres such as the geosphere and atmosphere.
There are about 1.4 billion km of water on Earth. That includes liquid water in the ocean, lakes, and rivers. It includes frozen water in snow, ice, and glaciers, and water that’s underground in soils and rocks. It also includes water that is in the atmosphere as clouds and vapor. Water is always on the move changing from a solid to vapor to ice and back to water. Water stays on the Earth for various amounts of time. It can be minutes, days or years and it doesn't have any set schedule. A drop of water can be in the ocean for years, or evaporate after a few days. Water is constantly changing and moving forms. Climate change can alter the life of a drop of water. With global warming, water evaporates faster and the cycle keeps moving at faster rates. The key here is the water cycle and how this works on a daily basis.
Biosphere
All living organisms that exist within a given ecosphere. J.B. Lamarck defined the term biosphere. When modern biologists mention the biosphere they usually mean the best part of the Earth's crust, which is the lithosphere and hydrosphere, and of the lower parts of the Earth's lower parts, which is the troposphere. All these together and the living organisms make up the biosphere. Other authorities go further and define the biosphere as " the space of our planet that is taken up by living beings" or as " that part of the Earth's crust, of its hydrosphere and atmosphere, that builds the environment for life".
Atmosphere
The layer of an ecosphere that exists as a gas. The atmosphere is the most distant component sphere of matter from the planet's Center of mass, beyond which is Outer space.
The whole mass of air surrounding the Earth, the density of the atmosphere decreases outward, which pushes the oxygen inward allowing humans to breathe without consequence.
The general circulation of the atmosphere is defined as the zonally and temporally averaged wind and temperature fields.
Magnetosphere
The magnetic field of an ecosphere along with the charged particles that are being controlled by that magnetic field.
The Earth is one large magnet that is continuously subjected to plasma flow. The plasma flow is the solar wind that is propelled from the Sun. The interaction between solar wind and geomagnetic field eventually combine to result in the formation of an electrical current layer, which is called the magnetopause. This electric current layer confines the Earth's magnetic field. The region in which the magnetopause is enclosed in is known as the magnetosphere.
See also
Outline of Earth sciences
References
Biosphere
Ecosystems | Ecosphere (planetary) | [
"Biology"
] | 886 | [
"Symbiosis",
"Ecosystems"
] |
63,263,651 | https://en.wikipedia.org/wiki/List%20of%20summer%20toboggans | This is a list of summer toboggan installations worldwide, including both alpine slide
and mountain coaster types.
Andorra
Australia
Austria
Belgium
Canada
China
France
Germany
Hungary
Iran
Italy
Jamaica
Japan
Kazakhstan
New Zealand
Russia
Serbia
Spain
Sweden
Switzerland
Ukraine
United Kingdom
United States
Vietnam
References
Summer toboggans
Summer toboggans | List of summer toboggans | [
"Physics",
"Technology"
] | 63 | [
"Physical systems",
"Machines",
"Amusement rides"
] |
63,264,386 | https://en.wikipedia.org/wiki/Microwave%20Journal | Microwave Journal (abbreviated as MWJ), , is an American magazine. It was established in 1958 as an industry technical journal covering RF and microwave applications for practicing engineers and scientists. It is indexed and abstracted in the Science Citation Index The print magazine reaches 50,000 qualified readers monthly (print and digital distribution). The journal articles are reviewed for impact, relevance and accuracy by their editorial review board making them the only industry journal that is peer reviewed in this market. It had an impact factor of 0.35 in 2018 according to the Web of Science Journal list. It also publishes in Chinese bi-monthly reaching 10,000 readers in China. In 2017, a sister journal covering high speed digital applications was launched called Signal Integrity Journal. Both magazines are free to qualified subscribers and are advertiser supported.
References
External links
microwavejournal.com/
Online magazines published in the United States
Electrical and electronic engineering magazines
Magazines established in 1958
Engineering magazines | Microwave Journal | [
"Engineering"
] | 192 | [
"Electrical engineering",
"Electronic engineering",
"Electrical and electronic engineering magazines"
] |
63,264,755 | https://en.wikipedia.org/wiki/Lithium%20disilicate | Lithium disilicate (Li2Si2O5) is a chemical compound that is a glass ceramic. It is widely used as a dental ceramic due to its strength, machinability and translucency.
Use
Lithium disilicate has found applications in dentistry as a dental ceramic material for dental restorations such as crowns, bridges, and veneers in the form of Li2Si2O5. Lithium disilicate has an unusual microstructure that consists of many randomly oriented small and interlocking plate-like needle-like crystals. This structure causes cracks to be deflected, blunted, and/or to branch, which prevents cracks from growing. Lithium disilicate has a biaxial flexible strength in the range of 360 MPa to 400 MPa; in comparison, for metal ceramics this is around 80 to 100 MPa, for veneered zirconia it is approximately 100 MPa, and for leucite glass ceramic it is approximately 150 to 160 MPa. It has high hardness (5.92 +/- 0.18 GPa) and fracture toughness (3.3 +/- 0.14 MPa m1/2). In addition, it can be made to have an appearance that very closely resembles that of natural human teeth.
Lithium disilicate is also used as a non-conductive seal, enamel or feed-through insulator in nickel superalloys or stainless steel, as it has a high thermal expansion.
References
Inorganic silicon compounds
Lithium compounds | Lithium disilicate | [
"Chemistry"
] | 314 | [
"Inorganic silicon compounds",
"Inorganic compounds"
] |
63,264,796 | https://en.wikipedia.org/wiki/Hemolithin | Hemolithin (sometimes confused with the similar space polymer Hemoglycin) is a proposed protein containing iron and lithium, of extraterrestrial origin, according to an unpublished preprint. The result has not been published in any peer-reviewed scientific journal. The protein was purportedly found inside two CV3 meteorites, Allende and Acfer-086, by a team of scientists led by Harvard University biochemist Julie McGeoch. The report of the discovery was met with some skepticism and suggestions that the researchers had extrapolated too far from incomplete data.
Sources
The detected hemolithin protein was reported to have been found inside two CV3 meteorites Allende and Acfer 086. Acfer-086, where the complete molecule was detected rather than fragments (Allende), was discovered in Agemour, Algeria in 1990.
Structure
According to the researchers' mass spectrometry, hemolithin is largely composed of glycine and hydroxyglycine amino acids. The researchers noted that the protein was related to "very high extraterrestrial" ratios of Deuterium/Hydrogen (D/H); such high D/H ratios are not found anywhere on Earth, but are "consistent with long-period comets" and suggest, as reported, "that the protein was formed in the proto-solar disc or perhaps even earlier, in interstellar molecular clouds that existed long before the Sun’s birth".
A natural development of hemolithin may have started with glycine forming first, and then later linking with other glycine molecules into polymer chains, and later still, combining with iron and oxygen atoms. The iron and oxygen atoms reside at the end of the newly found molecule. The researchers speculate that the iron oxide grouping formed at the end of the molecule may be able to absorb photons, thereby enabling the molecule to split water (H2O) into hydrogen and oxygen and, as a result, produce a source of energy that might be useful to the development of life.
Exobiologist and chemist Jeffrey Bada expressed concerns about the possible protein discovery commenting, "The main problem is the occurrence of hydroxyglycine, which, to my knowledge, has never before been reported in meteorites or in prebiotic experiments. Nor is it found in any proteins. ... Thus, this amino acid is a strange one to find in a meteorite, and I am highly suspicious of the results." Likewise, Lee Cronin of the University of Glasgow stated, "The structure makes no sense."
History
Hemolithin is the name given to a protein molecule isolated from two CV3 meteorites, Allende and Acfer-086. Its deuterium to hydrogen ratio is 26 times terrestrial which is consistent with it having formed in an interstellar molecular cloud, or later in the protoplanetary disk at the start of the Solar System 4.567 billion years ago. The elements hydrogen, lithium, carbon, oxygen, nitrogen and iron that it is composed of, were all available for the first time 13 billion years ago after the first generation of massive stars ended in nucleosynthetic events.
The research leading to the discovery of Hemolithin started in 2007 when another protein, one of the first to form on Earth, was observed to entrap water. That property being useful to chemistry before biochemistry on earth developed, theoretical enthalpy calculations on the condensation of amino acids were performed in gas phase space asking: "whether amino acids could polymerize to protein in space?" - they could, and their water of condensation aided their polymerization. This led to several manuscripts of isotope and mass information on Hemolithin.
A comment from the Harvard research leader on Hemolithin/Hemoglycin JEMMc – Hemolithin is now termed hemoglycin. Hemoglycin, a space polymer of glycine and iron has been extensively characterized [1-11] and it does contain lithium in some samples [5]. The research and now needs to be considered in the context of 4 areas of astronomy and planetary science:
1st in astronomy, the period between Pop III and Pop II stars, when the constituent elements of hemoglycin first formed even as early as 500My into cosmic time [1].
2nd in molecular clouds and protoplanetary disks where the polymer is likely to form and function in accretion [6,9,10]. Thus, the polymer could be a major player in solar system formation throughout the Universe.
3rd after in-fall to planets like Earth, where on Earth it could have kick-started the “The Great Oxygenation Event” (GOE) [9].
4th on exo-planets that evolve biochemistry like Earth, it could be asked whether the formation of DNA involves hemoglycin as a template. Guanine and cytosine nucleotide bases could form and bind to the 5nm glycine rods of in-fall hemoglycin to start the coding of glycine [12].
Hemoglycin is not a biological molecule, being outside of biochemistry, that is, abiotic. It may have first formed 500 million years into cosmic time as a structure that could absorb photons from 0.2-15µm [7,8,9,10], be available throughout the Universe, and provide energy to drive adjacent space chemistry. On its in-fall to exo-planets like Earth it could absorb solar ultraviolet and donate energy to early chemical systems. Hemoglycin could therefore be thought of as an abiotic absorber of light, a supplier of energy and an accretor of matter.
Synthetic hemoglycin synthesis will be attempted in 2025 to aid acquisition of a refined x-ray diffraction set for its structure. Hemoglycin crystals from meteorites, and stromatolites, to date are fiber-like or multiple [6,8,9]. A comparison of the MALDI mass spectrometry fragmentation patterns [5,11] of synthetic and extracted hemoglycin will be informative.
1. McGeoch J. E. M. and McGeoch M. W. (2014) Polymer Amide as an Early Topology. PLoS ONE 9(7): e103036. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0103036
2. McGeoch J. E. M. and McGeoch M. W. (2015) Polymer amide in the Allende and Murchison meteorites. Meteoritics & Planetary Science 50, Nr12 1971-1983. https://onlinelibrary.wiley.com/doi/10.1111/maps.12558
3. McGeoch J. E. M. and McGeoch M. W. (2017) A 4641Da polymer of amino acids in Acfer-086 and Allende meteorites. https://arxiv.org/pdf/1707.09080.pdf
4. McGeoch M. W., Šamoril T., Zapotok D. and McGeoch J. E. M. (2018) Polymer amide as a carrier of 15N in Allende and Acfer 086 meteorites. https://arxiv.org/abs/1811.06578.
5. McGeoch M. W., Dikler S. and McGeoch J. E. M. (2021) Meteoritic Proteins with Glycine, Iron and Lithium https://arxiv.org/abs/2102.10700. [physics.chem-ph]
6. McGeoch J. E. M. and McGeoch M.W. (2021) Structural Organization of Space Polymers. Physics of Fluids 33, 6, June 29th. https://aip.scitation.org/doi/10.1063/5.0054860.
7. McGeoch J. E. M. and McGeoch M. W. (2022) Chiral 480nm absorption in the hemoglycin space polymer: a possible link to replication. Sci. Rept. 12 16198 DOI: 10.1038/s41598-022-21043-4 License CC BY 4.0
8. McGeoch M. W., Owen R., Jaho S. and McGeoch J. E. M. (2023) Hemoglycin visible fluorescence induced by X-rays. J. Chem. Phys. 158, 114901 (2023); https://doi.org/10.1063/5.0143945
9. McGeoch J. E. M., Frommelt A. J., Owen R., Cinque G., McClelland A., Lageson D. and McGeoch M. W. (2024) Fossil and present-day stromatolite ooids contain a meteoritic polymer of glycine and iron. Int. J. Astrobiology 23, e20, 1-21 https://doi.org/10.1017/S1473550424000168 & arXiv:2309.17195 [physics.geo-ph].
10. McGeoch J. E. M. and McGeoch M. W. (2024) Polymer amide as a source of the cosmic 6.2 micron emission and absorption arXiv:2309.14914 [astro-ph.GA]. Mon. Not. Roy. Astron. Soc. 530, 1163-1170. DOI: https://doi.org/10.1093/mnras/stae756.
11. McGeoch J. E. M and McGeoch M. W. (2024) Sea foam contains hemoglycin from cosmic dust. RSC Advances, 2024, 14, 36919 – 36929. https://doi.org/10.1039/d4ra06881e
12. Lei L. and Burton Z. F. (2021) Evolution of the genetic code, Transcription, 12:1, 28-53, DOI: 10.1080/21541264.2021.1927652
See also
Earliest known life forms
Evolutionary history of life
Extraterrestrial: The First Sign of Intelligent Life Beyond Earth
List of interstellar and circumstellar molecules
Panspermia
References
Astrobiology
Biological hypotheses
Iron compounds
Lithium compounds
Organolithium compounds
Origin of life
Panspermia
Prebiotic chemistry
Proteins | Hemolithin | [
"Chemistry",
"Astronomy",
"Biology"
] | 2,255 | [
"Biomolecules by chemical classification",
"Organolithium compounds",
"Origin of life",
"Panspermia",
"Speculative evolution",
"Prebiotic chemistry",
"Astrobiology",
"Reagents for organic chemistry",
"Biological hypotheses",
"Proteins",
"Astronomical sub-disciplines",
"Molecular biology"
] |
63,265,544 | https://en.wikipedia.org/wiki/Reid%27s%20paradox%20of%20rapid%20plant%20migration | Reid's Paradox of Rapid Plant Migration or Reid's Paradox, describes the observation from the paleoecological record that plant ranges shifted northward, after the last glacial maximum, at a faster rate than the seed dispersal rates commonly occur. Rare long-distance seed dispersal events have been hypothesized to explain these fast migration rates, but the dispersal vector(s) are still unknown. The plant species' geographic range expansion rates are compared to the actualistic rates of seed dispersal using mathematical models, and are graphically visualized using dispersal kernels. These observations made in the paleontological record, which inspired Reid's Paradox, are from fossilized remains of plant parts, including needles, leaves, pollen, and seeds, that can be used to identify past shifts in plant species' ranges.
Reid's Paradox is named after Clement Reid, a paleobotanist, who made the principle observations from the paleobotanical record in Europe in 1899. His comparison of oak tree seed dispersal rates, and the observed range of oak trees from the fossil record, did not concur. Reid hypothesized that diffusion was not a possible explanation for the observed paradox, and supplemented his hypothesis by noting that birds were the likely cause of long range seed dispersal. Reid's Paradox has been subsequently documented across Europe and North America.
Dispersal kernels
Dispersal kernels are statistical models that represent the probability of seed dispersal from the source tree. Realistic biological data is required to complete the models. These data are used to accurately fill in variables such as seed number, seed size, and reproductive age. Depending on the plant species, the variables in the equation will change. In the years since Reid hypothesized the methods for seed dispersal, the models have gained more complex elements which attempt to resolve Reid's Paradox.
The dispersal of seeds from a parent tree are initially occurs as a normal distribution, as predicted by a standard diffusion equation. However, biological phenomenon complicate the diffusion equation by adding biotic vectors of dispersal such as blue jays and eastern grey squirrels, species which possess caching behaviors, and abiotic agents of dispersal such as high velocity wind storms. These additional vectors of seed dispersal make the dispersal kernels have a "fat-tail", or a large kurtosis. This means that the probability of a long-range dispersal event is higher than that of the standard diffusion dispersal kernel. In order to resolve Reid's Paradox, the vector(s) of seed-dispersal, which give the dispersal kernel a fat-tail, must be identified.
Possible explanations for Reid's Paradox
Animal dispersal
Long distance seed-dispersal events due to animal-seed interactions (such as caching or endozoochorous dispersal) would fatten the tail of the dispersal kernels. To fully explain Reid's Paradox, these rare animal induced seed-dispersal events must have been more important during migration events than recognized or recorded currently.
Cryptic refugia
Small populations of plants may have grown closer to the ice sheets in microhabitats that possessed the habitat characteristics needed for growth and reproduction. This would minimize the actual post-glacial dispersal distance. Such hypothetical populations would not be abundant enough to leave fossil evidence, so have escaped detection. In North America, there is some genetic evidence of cryptic northern refugia for sugar maple and American beech.
References
Forest ecology
Conservation biology
Environmental modelling
Paleontology | Reid's paradox of rapid plant migration | [
"Biology",
"Environmental_science"
] | 693 | [
"Conservation biology",
"Environmental modelling"
] |
63,270,016 | https://en.wikipedia.org/wiki/Direction-preserving%20function | In discrete mathematics, a direction-preserving function (or mapping) is a function on a discrete space, such as the integer grid, that (informally) does not change too drastically between two adjacent points. It can be considered a discrete analogue of a continuous function.
The concept was first defined by Iimura. Some variants of it were later defined by Yang, Chen and Deng, Herings, van-der-Laan, Talman and Yang, and others.
Basic concepts
We focus on functions , where the domain X is a finite subset of the Euclidean space . ch(X) denotes the convex hull of X.
There are many variants of direction-preservation properties, depending on how exactly one defines the "drastic change" and the "adjacent points". Regarding the "drastic change" there are two main variants:
Direction preservation (DP) means that, if x and y are adjacent, then for all : . In words: every component of the function f must not switch signs between adjacent points.
Gross direction preservation (GDP) means that, if x and y are adjacent, then . In words: the direction of the function f (as a vector) does not change by more than 90 degrees between adjacent points. Note that DP implies GDP but not vice versa.
Regarding the "adjacent points" there are several variants:
Hypercubic means that x and y are adjacent iff they are contained in some axes-parallel hypercube of side-length 1.
Simplicial means that x and y are adjacent iff they are vertices of the same simplex, in some triangulation of the domain. Usually, simplicial adjacency is much stronger than hypercubic adjacency; accordingly, hypercubic DP is much stronger than simplicial DP.
Specific definitions are presented below. All examples below are for dimensions and for X = { (2,6), (2,7), (3, 6), (3, 7) }.
Properties and examples
Hypercubic direction-preservation
A cell is a subset of that can be expressed by for some . For example, the square is a cell.
Two points in are called cell connected if there is a cell that contains both of them.
Hypercubic direction-preservation properties require that the function does not change too drastically in cell-connected points (points in the same hypercubic cell).
f is called hypercubic direction preserving (HDP) if, for any pair of cell-connected points x,y in X, for all : . The term locally direction-preserving (LDP) is often used instead. The function fa on the right is DP.
Some authors use a variant requiring that, for any pair of cell-connected points x,y in X, for all : . A function f(x) is HDP by the second variant, iff the function g(x):=f(x)-x is HDP by the first variant.
f is called hypercubic gross direction preserving (HGDP), or locally gross direction preserving (LGDP), if for any pair of cell-connected points x,y in X, . Every HDP function is HGDP, but the converse is not true. The function fb is HGDP, since the scalar product of every two vectors in the table is non-negative. But it is not HDP, since the second component switches sign between (2,6) and (3,6): .
Some authors use a variant requiring that, for any pair of cell-connected points x,y in X, . A function f(x) is HGDP by the second variant, iff the function g(x):=f(x)-x is HGDP by the first variant.
Simplicial direction-preservation
A simplex is called integral if all its vertices have integer coordinates, and they all lie in the same cell (so the difference between coordinates of different vertices is at most 1).
A triangulation of some subset of is called integral if all its simplices are integral.
Given a triangulation, two points are called simplicially connected if there is a simplex of the triangulation that contains both of them.
Note that, in an integral triangulation, every simplicially-connected points are also cell-connected, but the converse is not true. For example, consider the cell . Consider the integral triangulation that partitions it into two triangles: {(2,6),(2,7),(3,7)} and {(2,6),(3,6),(3,7)}. The points (2,7) and (3,6) are cell-connected but not simplicially-connected.
Simplicial direction-preservation properties assume some fixed integral triangulation of the input domain. They require that the function does not change too drastically in simplicially-connected points (points in the same simplex of the triangulation). This is, in general, a much weaker requirement than hypercubic direction-preservation.
f is called simplicial direction preserving (SDP) if, for some integral triangulation of X, for any pair of simplicially-connected points x,y in X, for all : .
f is called simplicially gross direction preserving (SGDP) or simplicially-local gross direction preserving (SLGDP) if there exists an integral triangulation of ch(X) such that, for any pair of simplicially-connected points x,y in X, .
Every HGDP function is SGDP, but HGDP is much stronger: it is equivalent to SGDP w.r.t. all possible integral triangulations of ch(X), whereas SGDP relates to a single triangulation. As an example, the function fc on the right is SGDP by the triangulation that partitions the cell into the two triangles {(2,6),(2,7),(3,7)} and {(2,6),(3,6),(3,7)}, since in each triangle, the scalar product of every two vectors is non-negative. But it is not HGDP, since .
References
Theory of continuous functions
Types of functions
Discrete mathematics | Direction-preserving function | [
"Mathematics"
] | 1,340 | [
"Functions and mappings",
"Discrete mathematics",
"Theory of continuous functions",
"Mathematical objects",
"Topology",
"Mathematical relations",
"Types of functions"
] |
63,270,274 | https://en.wikipedia.org/wiki/Eric%20Urban | Eric Jean-Paul Urban is a professor of mathematics at Columbia University working in number theory and automorphic forms, particularly Iwasawa theory.
Career
Urban received his PhD in mathematics from Paris-Sud University in 1994 under the supervision of Jacques Tilouine. He is a professor of mathematics at Columbia University.
Research
Together with Christopher Skinner, Urban proved many cases of Iwasawa–Greenberg main conjectures for a large class of modular forms. As a consequence, for a modular elliptic curve over the rational numbers, they prove that the vanishing of the Hasse–Weil L-function L(E, s) of E at s = 1 implies that the p-adic Selmer group of E is infinite. Combined with theorems of Gross-Zagier and Kolyvagin, this gave a conditional proof (on the Tate–Shafarevich conjecture) of the conjecture that E has infinitely many rational points if and only if L(E, 1) = 0, a (weak) form of the Birch–Swinnerton-Dyer conjecture. These results were used (in joint work with Manjul Bhargava and Wei Zhang) to prove that a positive proportion of elliptic curves satisfy the Birch–Swinnerton-Dyer conjecture.
Awards
Urban was awarded a Guggenheim Fellowship in 2007.
Selected publications
References
External links
20th-century French mathematicians
21st-century French mathematicians
Number theorists
Living people
Date of birth missing (living people)
Place of birth missing (living people)
Columbia University faculty
University of Paris alumni
Year of birth missing (living people) | Eric Urban | [
"Mathematics"
] | 316 | [
"Number theorists",
"Number theory"
] |
63,270,336 | https://en.wikipedia.org/wiki/Jacques%20Tilouine | Jacques Tilouine is a professor of mathematics at Université Sorbonne Paris Nord working in number theory and automorphic forms, particularly Iwasawa theory.
Career
Tilouine received his PhD in mathematics from Paris-Sud University in 1989 under the supervision of John H. Coates. He is a professor of mathematics at Université Sorbonne Paris Nord.
Research
Tilouine has worked on the anticyclotomic main conjecture of Iwasawa theory, special values of L-functions, and Serre-type conjectures for symplectic groups.
Selected publications
References
External links
20th-century French mathematicians
21st-century French mathematicians
Number theorists
Living people
Date of birth missing (living people)
Place of birth missing (living people)
University of Paris alumni
Academic staff of the University of Paris
Year of birth missing (living people) | Jacques Tilouine | [
"Mathematics"
] | 164 | [
"Number theorists",
"Number theory"
] |
63,270,728 | https://en.wikipedia.org/wiki/Canagliflozin/metformin | Canagliflozin/metformin, sold under the brand name Vokanamet among others, is a fixed-dose combination anti-diabetic medication used for the treatment of type 2 diabetes. It is used in combination with diet and exercise. It is taken by mouth.
The most common side effects include hypoglycemia (low blood glucose levels) when used in combination with insulin or a sulphonylurea and vulvovaginal candidiasis (thrush, a fungal infection of the female genital area caused by Candida).
Canagliflozin/metformin was approved for medical use in the European Union in April 2014, and for use in the United States in August 2014.
Medical uses
Canagliflozin/metformin is indicated in adults aged 18 years of age and older with type 2 diabetes as an adjunct to diet and exercise to improve glycemic control.
Adverse effects
To lessen the risk of developing ketoacidosis (a serious condition in which the body produces high levels of blood acids called ketones) after surgery, the FDA approved changes to the prescribing information for SGLT2 inhibitor diabetes medicines to recommend they be stopped temporarily before scheduled surgery. Canagliflozin, dapagliflozin, and empagliflozin should each be stopped at least three days before, and ertugliflozin should be stopped at least four days before scheduled surgery.
Symptoms of ketoacidosis include nausea, vomiting, abdominal pain, tiredness, and trouble breathing.
References
Further reading
Biguanides
Combination diabetes drugs
Fluoroarenes
Glucosides
Guanidines
SGLT2 inhibitors
Thiophenes | Canagliflozin/metformin | [
"Chemistry"
] | 360 | [
"Guanidines",
"Functional groups"
] |
63,274,769 | https://en.wikipedia.org/wiki/2003%20United%20States%20smallpox%20vaccination%20campaign | The 2003 United States smallpox vaccination campaign was a vaccination program announced by the White House on 13 December 2002 as preparedness for bioterrorism using smallpox virus. The campaign aimed to provide the smallpox vaccine to those who would respond to an attack, establishing Smallpox Response Teams and using DryVax (containing the NYCBOH strain) to mandatorily vaccinate half a million American military personnel, followed by half a million health care worker volunteers by January 2004. The first vaccine was administered to then-President George W. Bush.
The campaign ended early in June 2003, with only 38,257 civilian health care workers vaccinated, after several hospitals refused to participate due to the risk of the live virus infecting vulnerable patients and skepticism about the risks of an attack, and after over 50 heart complications were reported by the CDC. That August, the US Institute of Medicine (IOM) criticized the programme for its costs and not considering other bioterrorism control measures such as surveillance. The adverse cardiac events, including two deaths, were however unlikely to have been caused by the vaccine. A 2005 IOM report noted that some of the problems of the campaign stemmed from administration officials overruling scientific advice on the numbers who should be vaccinated and a lack of communication by the CDC of the public health need, though it found that the campaign had increased general preparedness for sudden occurrences of infectious diseases like that year's monkeypox outbreak and the 2002–2004 SARS outbreak.
References
Smallpox vaccines
Vaccination in the United States
2003 in the United States
Disaster preparedness in the United States
Bioterrorism | 2003 United States smallpox vaccination campaign | [
"Biology"
] | 334 | [
"Bioterrorism",
"Biological warfare"
] |
63,276,409 | https://en.wikipedia.org/wiki/Gram%E2%80%93Euler%20theorem | In geometry, the Gram–Euler theorem, Gram-Sommerville, Brianchon-Gram or Gram relation (named after Jørgen Pedersen Gram, Leonhard Euler, Duncan Sommerville and Charles Julien Brianchon) is a generalization of the internal angle sum formula of polygons to higher-dimensional polytopes. The equation constrains the sums of the interior angles of a polytope in a manner analogous to the Euler relation on the number of d-dimensional faces.
Statement
Let be an -dimensional convex polytope. For each k-face , with its dimension (0 for vertices, 1 for edges, 2 for faces, etc., up to n for P itself), its interior (higher-dimensional) solid angle is defined by choosing a small enough -sphere centered at some point in the interior of and finding the surface area contained inside . Then the Gram–Euler theorem states: In non-Euclidean geometry of constant curvature (i.e. spherical, , and hyperbolic, , geometry) the relation gains a volume term, but only if the dimension n is even:Here, is the normalized (hyper)volume of the polytope (i.e, the fraction of the n-dimensional spherical or hyperbolic space); the angles also have to be expressed as fractions (of the (n-1)-sphere).
When the polytope is simplicial additional angle restrictions known as Perles relations hold, analogous to the Dehn-Sommerville equations for the number of faces.
Examples
For a two-dimensional polygon, the statement expands into:where the first term is the sum of the internal vertex angles, the second sum is over the edges, each of which has internal angle , and the final term corresponds to the entire polygon, which has a full internal angle . For a polygon with faces, the theorem tells us that , or equivalently, . For a polygon on a sphere, the relation gives the spherical surface area or solid angle as the spherical excess: .
For a three-dimensional polyhedron the theorem reads:where is the solid angle at a vertex, the dihedral angle at an edge (the solid angle of the corresponding lune is twice as big), the third sum counts the faces (each with an interior hemisphere angle of ) and the last term is the interior solid angle (full sphere or ).
History
The n-dimensional relation was first proven by Sommerville, Heckman and Grünbaum for the spherical, hyperbolic and Euclidean case, respectively.
See also
Euler characteristic
Dehn-Sommerville equations
Angular defect
Gauss-Bonnet theorem
References
Polytopes
Real algebraic geometry
Geometry | Gram–Euler theorem | [
"Mathematics"
] | 556 | [
"Mathematical theorems",
"Mathematical problems",
"Geometry",
"Theorems in geometry"
] |
63,277,433 | https://en.wikipedia.org/wiki/Erin%20Hotchkiss | Erin Hotchkiss is an ecologist who studies climate change's specific impact on freshwater ecosystems (rivers, lakes, wetlands). She researches the relationships between organisms and water quality in freshwater ecosystems, how processes on land influence water, and the sources and fate of carbon and nutrients in aquatic ecosystems. Hotchkiss is currently an Assistant Professor in the Department of Biological Studies at Virginia Polytechnic Institute and State University.
Early life and education
Hotchkiss was born in Washington D.C. but later moved to northern California and then Oak Ridge, Tennessee. Hotchkiss grew up playing outside with her favorite memories from childhood including the exploration of tide pools and the beach at low tide, curious to see what creatures were living there. Hotchkiss entered freshwater ecology connected to and inspired by water.
Hotchkiss earned her Bachelors in Science for Environmental Studies in 2003 from Emory University. In 2007, Hotchkiss went on to receive her masters in Zoology and Physiology from the University of Wyoming. Here, Hotchkiss wrote her thesis: Impacts of exotic snails on stream carbon cycling. Staying at the University of Wyoming in 2013, Hotchkiss earned her Ph.D. in ecology and her dissertation focused on carbon cycling in streams.
Career
As a Postdoctoral Research Fellow from 2013 to 2015, Hotchkiss worked at Umeå University in Sweden, researching ecosystem metabolism and carbon emissions from river networks. From 2015 to 2016 Hotchkiss worked as a postdoctoral research fellow at the Université du Québec à Montréal, Canada. Here, Hotchkiss focused on the biogeochemistry of northern aquatic ecosystems. In 2016, Hotchkiss started at Virginia Polytechnic Institute and State University as an Assistant Professor of Biological Sciences.
Research
Hotchkiss works to uncover the impacts of environmental change on freshwater ecosystems. She uses empirical data and models to measure carbon cycling in aquatic ecosystems. Much of her field work focuses on stream metabolism and the fate of terrestrial materials in freshwater. Hotchkiss combines her knowledge in her three fields of study: chemistry, biology, and hydrology to quantify environmental changes in freshwater.
Erin Hotchkiss has published many valuable scientific articles that have received awards and have been cited by others in her field. One of Hotchkiss' most notable articles from 2015 is entitled, Sources of and processes controlling CO2 emissions change with the size of streams and rivers. Her work uncovers the effect of CO2 emissions in different size streams and rivers and gives key evidence for carbon cycling in rivers. Hotchkiss examines the relationships between stream geometry, chemistry, and ecosystem metabolism. The process of stream metabolism includes such metrics as ecosystem respiration (ER), gross primary production (GPP), and their difference, net ecosystem production (NEP). This work found that CO2 emissions in small streams are mainly derived from terrestrial sources, while internal processing (i.e. stream metabolism) is a more important source of CO2 release within larger rivers. These findings are significant as they provide evidence of the importance of inland waterways and aquatic ecosystem metabolism within the global carbon cycle.
Some other of Hotchkiss' notable work includes:
Hotchkiss, E.R.*, S. Sadro, & P.C. Hanson. 2018. Toward a more integrative perspective on carbon metabolism across lentic and lotic inland waters. Limnology & Oceanography
Hotchkiss, E.R.* & R.O. Hall. 2015. Whole-stream 13C tracer addition reveals distinct fates of newly fixed carbon.
Hotchkiss, E.R.* & R.O. Hall. 2014. High rates of daytime respiration in three streams: Use of δ18O2 and O2 to model diel ecosystem metabolism.
Awards and honors
Erin Hotchkiss was recognized as a notable early career scientist with two awards:
Hynes Award for New Investigators from the Society for Freshwater Science (2016)
Raymond L. Lindeman Award from the Association for the Sciences of Limnology and Oceanography (2016)
References
External links
American ecologists
American women ecologists
American environmental scientists
21st-century American scientists
21st-century American women scientists
Virginia Tech faculty
University of Wyoming alumni
Emory University alumni
Living people
Year of birth missing (living people)
American women academics | Erin Hotchkiss | [
"Environmental_science"
] | 882 | [
"American environmental scientists",
"Environmental scientists"
] |
63,277,695 | https://en.wikipedia.org/wiki/Pearls%20in%20Graph%20Theory | Pearls in Graph Theory: A Comprehensive Introduction is an undergraduate-level textbook on graph theory by Nora Hartsfield and Gerhard Ringel. It was published in 1990 by Academic Press with a revised edition in 1994 and a paperback reprint of the revised edition by Dover Books in 2003. The Basic Library List Committee of the Mathematical Association of America has suggested its inclusion in undergraduate mathematics libraries.
Topics
The "pearls" of the title include theorems, proofs, problems, and examples in graph theory. The book has ten chapters; after an introductory chapter on basic definitions, the remaining chapters material on graph coloring; Hamiltonian cycles and Euler tours; extremal graph theory; subgraph counting problems including connections to permutations, derangements, and Cayley's formula; graph labelings; planar graphs, the four color theorem, and the circle packing theorem; near-planar graphs; and graph embedding on topological surfaces.
The book also includes several unsolved problems such as the Oberwolfach problem on covering complete graphs by cycles, the characterization of magic graphs, and Ringel's Earth–Moon problem on coloring biplanar graphs.
Despite its subtitle "A comprehensive introduction", the book is short and its selection of topics reflects author Ringel's personal interests.. Important topics in graph theory that are not coveredinclude the symmetries of graphs, cliques, connections between graphs and linear algebra including adjacency matrices, algebraic graph theory and spectral graph theory, connectivity of a graph (or even biconnected components), Hall's marriage theorem, line graphs, interval graphs, and the theory of tournaments. There is also only one chapter of coverage on algorithms and real-world applications of graph theory. Also, the book omits "difficult or long proofs".
Audience and reception
The book is written as a lower-level undergraduate textbook and recommends that students using it have previously taken a course in discrete mathematics. Nevertheless, it can be read and understood by students with only a high school background in mathematics. Reviewer L. W. Beineke writes that the variety of levels of the exercises is one of the strengths of the book, and reviewer John S. Maybee writes that they are "extensive" and provide interesting connections to additional topics; however, reviewer J. Sedláček criticizes them as "routine".
Although several reviewers complained about the book's spotty or missing coverage of important topics, reviewer Joan Hutchinson praised its choice of topics as "refreshingly different" and noted that, among many previous texts on graph theory, none had as much depth of coverage of topological graph theory. Other reviewer complaints include a misattributed example, a bad definition of the components of a graph that failed to apply to graphs with one component, and a proof of the five-color theorem that only applies to special planar maps instead of all planar graphs.
Despite these complaints, Beineke writes that, as an undergraduate text, "this book has much to offer". Maybee writes that the book was "a joy to read", provided better depth of coverage on some topics than previous graph theory texts, and would be helpful reading for "many graph theorists". Hutchinson praises it as providing "a splendid, enticingly elementary yet comprehensive introduction to topological graph theory".
References
External links
Pearls in Graph Theory (1st ed.) at the Internet Archive
Graph theory
Mathematics textbooks
1990 non-fiction books
1994 non-fiction books
2003 non-fiction books | Pearls in Graph Theory | [
"Mathematics"
] | 721 | [
"Discrete mathematics",
"Mathematical relations",
"Graph theory",
"Combinatorics"
] |
63,278,211 | https://en.wikipedia.org/wiki/Animal%20products%20in%20pharmaceuticals | Animal products in pharmaceuticals play a role as both active and inactive ingredients, the latter including binders, carriers, stabilizers, fillers, and colorants. Animals and their products may also be used in pharmaceutical production without being included in the product itself.
The religious, cultural, and ethical concerns of patients and the disclosure of animal ingredients in pharmaceuticals are a growing area of concern for some people. These would include people who abide by veganism ("vegans"), the practice of abstaining from the use of animal products. Vegan medicines are medications and dietary supplements that do not have any ingredients of animal origin. The vegan status can be determined either through self-proclamation of the company or certification from a third-party organization, such as The Vegan Society or PETA.
Desire for ingredient information
There is public interest in knowing whether medications and supplements contain animal-sourced ingredients. In a study of 100 people, 84% reported not knowing that several medications contained ingredients derived from animal sources. Nearly 63% of the people wanted their physicians, and 35% of the people wanted other healthcare providers (pharmacists, nurses), to notify them when using such medications. Alternatives exist for many animal-derived ingredients, and healthcare providers are increasingly incorporating awareness around animal-free drugs in their medical practice.
A 2013 study in the BMC Medical Ethics contacted branches of six of the world's largest religions. Of the six religions contacted, respondents from three did not accept or approve of the use of animal products in pharmaceuticals. The authors concluded that: Similarly, a 2014 BMJ analysis on the topic discussed the lack of information about ingredients available to doctors. According to the article, "Most medications prescribed in primary care contain animal derived products" and "Disclosure of animal content and excipients would help patients make an informed personal choice"
Active ingredients in drugs and dietary supplements
Biomedicine
Insulin from cattle and pigs has been used since the 1920s, and was the predominant form of insulin used for decades. The first synthetic human insulin was created using bacteria in 1978. In the United States, the manufacture of beef insulin was discontinued in 1998, and the manufacture of pork insulin was discontinued in 2006.
Premarin, a hormone replacement therapy, is a conjugated estrogen. It was first available in the form of a preparation manufactured from the urine of pregnant mares - hence "Premarin" from "PREgnant MARe's urINe". It is now also made as a fully synthetic product.
Dietary supplements
Glucosamine, used in dietary supplements marketed for osteoarthritis, is extracted from chitin from shellfish. Non-animal sourced glucosamine is also available.
Cartilage as a dietary supplement is by definition animal-sourced. Shark cartilage is marketed explicitly or implicitly as a treatment or preventive for various illnesses, including cancer. There is no consensus that shark cartilage is useful in treating or preventing cancer or other diseases.
Traditional Chinese Medicine
Traditional Chinese Medicine (TCM) utilizes approximately 1,000 plant species and 36 animal species. Animal ingredients in TCM include animal parts such as tiger bones, rhino horns, deer antlers, and snake bile. The use of animal parts in TCM have been definitively linked to the extinction of wildlife. One example of this link is the pangolin trade, which has led the pangolin to be called the world's "most trafficked mammal." In 2020, pangolin scales were removed from the Chinese list of ingredients approved for use in Traditional Chinese Medicine.
Homeopathic medicine
Homeopathic medicine is made of plants, minerals, or animal parts. Oscillococcinum, a remedy purported to reduce cold and flu like symptoms, is made of duck heart and liver. There is also use of insects in homeopathic medicine, such as Blatta orientalis, a type of cockroach which has been studied by homeopaths for anti-asthmatic effects.
Inactive ingredients
Gelatin is derived from animal skin, bone, and tissue most often from pigs or beef. There is no practical way of determining if the gelatin used in pharmaceuticals is derived from beef or pork. It is used primarily for gel capsules and as stabilizers for vaccines. Non-animal derived alternatives to gelatin include pectin as a gelling agent or cellulose for creating capsules.
Lactose is derived from cow's milk and is a frequently used filler or binder in tablets and capsules.
Magnesium stearate is the most commonly used emulsifier, binder, thickener, or lubricant. It can be derived from animal- or plant-sourced stearic acid, although it is most commonly sourced from cottonseed oil or palm oil.
Sodium tallowate is a common soap ingredient derived from tallow—the fat of animals such as cattle and sheep. A popular alternative to this ingredient is sodium palmate, which is derived from palm oil. Soap is a pharmaceutical according to the United States Food and Drug Administration.
Shellac is a resin excreted by female insects of the species Kerria lacca. It is used as a glazing agent on pills.
Carmine, derived from crushed cochineal beetles, is a red or purple substance commonly used in pharmaceutical products. Evidence shows that it can be allergenic. Carmine is an allergen according to the US Food and Drug Administration (FDA). The FDA requires this ingredient to be declared in food and cosmetics, but not pharmaceuticals.
Animal use during product development or production
A separate issue is the use of testing on animals as a means of initial testing during drug development, or actual production. Guiding principles for more ethical use of animals in testing are the Three Rs first described by Russell and Burch in 1959. These principles are now followed in many testing establishments worldwide.
Replacement refers to the preferred use of non-animal methods over animal methods whenever it is possible to achieve the same scientific aim.
Reduction refers to methods that enable researchers to obtain comparable levels of information from fewer animals, or to obtain more information from the same number of animals.
Refinement refers to methods that alleviate or minimize potential pain, suffering, or distress, and enhance animal welfare for the animals used.
Cow blood is used in vaccine manufacture. Microorganisms for vaccine manufacture are grown under controlled conditions in liquid solutions ("media") which provide the nutrients necessary for growth. These can include cow plasma. Chicken eggs are used in the production process of some vaccines. For influenza vaccination there are non-egg alternatives.
See also
Biopharmaceutical
Animal rights by country or territory
Animal rights in Jainism, Hinduism, and Buddhism
Alpha-gal allergy
Further reading
Medicines Derived From Animal Products - Rotherham NHS foundation trust
Information on Animal-Derived Ingredients in Medicines Difficult to Obtain in The Pharmaceutical Journal
References
Animal testing | Animal products in pharmaceuticals | [
"Chemistry"
] | 1,402 | [
"Animal testing"
] |
62,363,990 | https://en.wikipedia.org/wiki/The%20American%20City%20%28magazine%29 | The American City was an American municipal affairs and urban planning magazine published by Buttenheim Publication Corporation from 1909 through 1942. It was based in New York City. The publication was primarily concerned with the design, care, and maintenance of civic infrastructure such as roads, parks, public buildings and public safety design. It was intended to be read by municipal officials and civic workers. There were two separate editions of The American City, a city and a "town and country" edition. These merged in 1920.
It was edited by Arthur Hastings Grant until 1911 and then by Harold S. Buttenheim through 1942. The Buttenheim Brothers, Harold and Edgar, also founded the American City Bureau, which raised funds for local Community Chests, YMCA and YWCAs, and similar agencies.
References
External links
The American City (v. 2-29) at Hathi Trust
Magazines established in 1909
Magazines published in New York City
Monthly magazines published in the United States
Science and technology magazines published in the United States
Urban planning | The American City (magazine) | [
"Engineering"
] | 203 | [
"Urban planning",
"Architecture"
] |
62,364,230 | https://en.wikipedia.org/wiki/The%20Investigator%20%28TV%20pilot%29 | The Investigator is a 1973 British television pilot devised, produced and directed by Gerry Anderson, creator of Thunderbirds and other Supermarionation TV series of the 1960s. It centres on two American youths, John and Julie, who have been recruited by an extragalactic being called "the Investigator" to aid his self-appointed task of ridding Earth of evil and corruption. Miniaturised and given special knowledge and abilities, they take on Stavros Karanti, an unscrupulous businessman plotting to steal a priceless painting from a Maltese cathedral. Shane Rimmer and Sylvia Anderson voice John and Julie, who are represented by marionette puppets, while Charles Thake and Peter Borg appear as Karanti and his minion Christoph.
The pilot marked Gerry Anderson's first use of puppets since The Secret Service (1969). Written by his wife Sylvia from a story by Rimmer, it was filmed on location in Malta between the production of The Protectors and a planned second series of UFO (which would later be made as Space: 1999). Filming was complicated by numerous technical and logistical difficulties and the crew were unable to finish the shoot. The pilot was assembled from the incomplete footage but Anderson, disappointed with the result, abandoned his idea of pitching it to NBC as the basis for a new Supermarionation series. Unaired to date, the pilot has received a negative response from commentators. It was released on DVD in 2012 and 2015.
Plot
The Investigator, an omniscient being from another galaxy, has come to Earth to rid it of evil and corruption. To assist him, he has recruited two young Americans, John and Julie, whom he has miniaturised and given special powers. In a cave on Malta, the Investigator (represented by a flashing green light) gives John and Julie their first assignment: they are to foil crooked entrepreneur Stavros Karanti's plan to steal a priceless Raphael painting from St John's Cathedral in Mdina. To aid their mission, he provides them with an eight-wheel miniature car equipped with powerful surveillance devices. Thanks to his new abilities, John instantly knows how to drive the car.
John and Julie go to Angel's Leap and spy on Karanti as he boards his yacht, the Borgia, and meets his associate Christoph. When the men come ashore and drive to Mdina, John and Julie follow. While touring St John's, to which he has donated a fake painting, Karanti learns of the cathedral's security arrangements. Karanti and Christoph return to the Borgia pursued by John and Julie, who board the yacht via a miniature speedboat provided by the Investigator. The youths accidentally knock over an object, alerting the criminals to their presence, but avoid being discovered thanks to their small size.
Returning to St John's at night with John and Julie again on their tail, Karanti and Christoph knock out the cathedral's security guard and seize the Raphael painting. John tries to stop the criminals by mounting a chandelier and swinging it at them. Karanti fires a gun at John, missing him but causing him to fall to the floor, injured. Karanti and Christoph get away. Leaving Christoph at the harbour, Karanti drives to a nearby airfield, planning to leave Malta in his Cessna 150 plane. John and Julie beat him to the airfield and stow away aboard the Cessna before Karanti takes off. Speaking through a miniature megaphone, John pretends to be Karanti's conscience urging him to surrender. At the same time, Julie uses a remote control to make the plane repeatedly roll and dive, terrifying Karanti. On John's instructions, Karanti radios air traffic control to confess his crimes and lands at the airfield, where he is arrested by police.
With the painting safely returned to the cathedral, John and Julie report back to the Investigator, who congratulates them on a job well done.
Cast
Charles Thake as Karanti
Peter Borg as Christoph
Sylvia Anderson as Voice of Julie
Shane Rimmer as Voice of John
Peter Dyneley as Voice of The Investigator
Production
The Investigator was Gerry Anderson's first puppet production since The Secret Service (1969), the last Supermarionation series to be made by his former company Century 21 Productions. Having gone on to make the live-action series UFO and The Protectors, neither of which were made specifically for children, Anderson wanted to create something new for the younger audience and devised The Investigator as the template for a new Supermarionation programme, intending to pitch it to American network NBC in the hope that it would commission a series. The pilot was planned by Anderson, his wife Sylvia and their long-time business partner Reg Hill. Written by Sylvia from a story by Shane Rimmer, it was funded by private venture capital and produced by off-the-shelf company Starkits between The Protectors and a planned second series of UFO (which was later made as Space: 1999).
The project saw the return of several crew members from the Supermarionation years, such as co-editor David Lane, as well as the reunion of voice actors Sylvia, Rimmer and Peter Dyneley, all of whom had voiced characters in Thunderbirds. Charles Thake had previously appeared in an episode of The Protectors. The John and Julie puppets were tall and made in the naturally-proportioned style that Century 21 had introduced for Captain Scarlet and the Mysterons (1967). Unlike the puppets of 1960s Supermarionation, which had been controlled from overhead bridges, they were operated from the ground with the puppeteers standing on boxes. Julie was modelled on Raquel Welch. Modified versions of the puppets later appeared in Alien Attack, a 1977 TV advertisement produced by Gerry Anderson. The model car and speedboat were designed by Hill and operated by radio control.
The Investigator was shot entirely on location in Malta, which had served as a location for The Protectors and was chosen for its architecture and scenery. Specific locations included the Main Gate and St Paul's Cathedral in Mdina as well as Malta International Airport. Filming was beset by technical and logistical problems. Low light meant that the crew often had to shoot in close-up, which made it hard to capture the scale and detail of the locations. The model car was affected by radio signals from RAF Nimrods, causing it to crash into objects or speed off in the wrong direction. Poor weather also disrupted the proceedings. At one point, heavy rain forced the crew to film outdoor scenes under a plastic cover that started to leak, soaking the set. On another occasion, a storm hit while Gerry Anderson was on Malta and the rest of the unit were on Gozo, leaving the director and his crew cut off from each other and causing the production to lose a day. Another day was lost when the sailing yacht doubling as the Borgia fouled its anchor.
Anderson did not have facilities in Malta to view rushes from the production. Footage was instead flown back to the UK, where it was processed by Hill. Eventually the production's schedule ran out and the crew were forced to return to the UK before they had finished filming. This meant that the aerial footage for the scenes aboard Karanti's plane had to be shot over the English countryside. The pilot was then put together using the material available.
The theme music was composed by Vic Elmes, Sylvia Anderson's then son-in-law. Elmes was originally to have scored the entire pilot, but Gerry Anderson was unimpressed with his efforts and replaced him with John Cameron, the composer for The Protectors. The incidental music was recycled from Cameron's work on that series.
Reception
The Andersons and Hill were disappointed with the finished pilot and abandoned the idea of pitching it, feeling that its quality was too low to satisfy NBC or any other broadcaster. Gerry Anderson's opinions on The Investigator ranged from a "pretty dull, uninspired piece of filmmaking" to a "disaster". He regretted serving as both director and producer as he felt that his need to limit costs as producer compromised his vision as director. In his 1996 biography, he called the project an "absolute non-starter" and reflected that "everything, but everything went wrong on The Investigator."
Simon Archer and Marcus Hearn compare The Investigator to The Secret Service, which combined puppets and live actors in a similar way. They describe it as an "extrapolation" of the earlier series. Ian Fryer suggests that The Investigator "pushed the notion further" by being filmed entirely on location. He argues that the pilot displays "decent professional standards" and that the "sketchiness" of the premise can be justified by the fact that unlike the first episodes of the Supermarionation productions, where all story elements had been approved prior to filming, The Investigator was made as a "true pilot" whose elements were still subject to approval. He praises the model work, believing the car and speedboat to be well designed despite the low budget, but regards John and Julie as poorly-developed characters, pointing out that they receive a shorter introduction than the car. Suggesting that an Investigator series could have been a "junior version" of Mission: Impossible, noting that 1973 was the "tail end of the post-Bond craze", Fryer acknowledges the pilot's failure, concluding that "the return of Supermarionation died, unheralded, on the rain-swept streets of Malta."
TV Zone magazine comments that the lack of puppet movement "does little to enliven the characters" and calls The Investigator a "poor attempt to recreate the heyday of Century 21". SFX describes it as a "weirdly forlorn thing" and "existentially peculiar even by Anderson's standards." According to Anderson's son Jamie, The Investigator "lacked the science fiction context that made [his] previous shows so successful."
Other media
Toy versions of the car and speedboat were produced by Dinky. However, the toys' launch was cancelled when it became clear that no series would be made. After being redesigned and repackaged to omit all references to The Investigator, the car and speedboat eventually went on sale in 1975 and 1977 respectively.
For many years The Investigator was unavailable on any home video format, although fan-made copies existed and it was screened at Anderson conventions. In 2012, Fanderson released a DVD of The Investigator exclusively for its members. The print used to make the DVD had been restored by BBC Resources, which also recreated its missing closing titles. The Investigator was later included in 2015's "The Lost Worlds of Gerry Anderson" DVD by Network.
References
Works cited
External links
1973 in British television
British English-language television shows
British science fiction television films
British television shows featuring puppetry
Works set in cathedrals
Fiction about size change
Marionette films
Television episodes about alien visitations
Television episodes about theft
Television episodes set in Malta
Unaired television pilots
Works by Gerry Anderson | The Investigator (TV pilot) | [
"Physics",
"Mathematics"
] | 2,228 | [
"Fiction about size change",
"Quantity",
"Physical quantities",
"Size"
] |
62,364,657 | https://en.wikipedia.org/wiki/Hoffman%27s%20packing%20puzzle | Hoffman's packing puzzle is an assembly puzzle named after Dean G. Hoffman, who described it in 1978. The puzzle consists of 27 identical rectangular cuboids, each of whose edges have three different lengths. Its goal is to assemble them all to fit within a cube whose edge length is the sum of the three lengths.
writes that the first person to solve the puzzle was David A. Klarner, and that typical solution times can range from 20 minutes to multiple hours.
Construction
The puzzle itself consists only of 27 identical rectangular cuboid-shaped blocks, although physical realizations of the puzzle also typically supply a cubical box to fit the blocks into. If the three lengths of the block edges are , , and , then the cube should have edge length .
Although the puzzle can be constructed with any three different edge lengths, it is most difficult when the three edge lengths of the blocks are close enough together that , as this prevents alternative solutions in which four blocks of the minimum width are packed next to each other. Additionally, having the three lengths form an arithmetic progression can make it more confusing, because in this case placing three blocks of the middle width next to each other produces a row of the correct total width but one that cannot lead to a valid solution to the whole puzzle.
Mathematical analysis
Each valid solution to the puzzle arranges the blocks in an approximate grid of blocks, with the sides of the blocks all parallel to the sides of the outer cube, and with one block of each width along each axis-parallel line of three blocks. Counting reflections and rotations as being the same solution as each other, the puzzle has 21 combinatorially distinct solutions.
The total volume of the pieces, , is less than the volume of the cube that they pack into. If one takes the cube root of both volumes, and divides by three, then the number obtained in this way from the total volume of the pieces is the geometric mean of , , and , while the number obtained in the same way from the volume of the cube is their arithmetic mean. The fact that the pieces have less total volume than the cube follows from the inequality of arithmetic and geometric means.
Table of solutions
The 21 distinct solutions are tabulated here as described by the references cited above .
All boxes below are entered in the format (east-west length) x (north-south length) x (up-down length), denoting the size of each box with the dimensions A, B, and C, where A < B < C. (In the above example, A = 4, B = 5, and C = 6).
All 3x3 matrices describe a set of 9 boxes, with east-west neighbors along each row and north-south neighbors down each column, with the three stacked layers being listed in sequence for each solution.
Higher dimensions
A two-dimensional analogue of the puzzle asks to pack four identical rectangles of side lengths and into a square of side length ; as the figure shows, this is always possible. In dimensions the puzzle asks to pack identical blocks into a hypercube. By a result of Raphael M. Robinson this is again solvable whenever for two numbers and such that the - and -dimensional cases are themselves solvable. For instance, according to this result, it is solvable for dimensions 4, 6, 8, 9, and other 3-smooth numbers. In all dimensions, the inequality of arithmetic and geometric means shows that the volume of the pieces is less than the volume of the hypercube into which they should be packed. However, it is unknown whether the puzzle can be solved in five dimensions, or in higher prime number dimensions.
References
Mechanical puzzle cubes
Packing problems | Hoffman's packing puzzle | [
"Mathematics"
] | 747 | [
"Mathematical problems",
"Packing problems"
] |
62,367,602 | https://en.wikipedia.org/wiki/Total%20sounding | Total sounding (TS) is a sounding method performed as part of geotechnical investigation. The sounding combines conventional rotary-pressure sounding with bedrock drilling, including rotation, ramming and flushing modes. The result indicates sediment stratification, occasionally soil type and may verify depth to bedrock.
History
The rotary-pressure sounding method was developed by the Norwegian Geotechnical Institute (NGI) and the Public Roads Administration (NPRA) in 1967.
References
External links
In situ geotechnical investigations | Total sounding | [
"Engineering"
] | 100 | [
"Civil engineering",
"Civil engineering stubs"
] |
62,367,635 | https://en.wikipedia.org/wiki/Rotary-pressure%20sounding | Rotary-pressure sounding is a method of testing soil conditions that might be performed as part of a geotechnical investigation. A series of rods, with a specially designed tip, is forced into the ground under downward pressure. The rotation and speed of insertion are maintained at a constant rate, and the amount of force required to maintain that rate is measured. The results can be interpreted to provide information about sediment stratification, and sometimes also the type of soil and the depth to bedrock.
The rotary-pressure sounding method was developed by the Norwegian Geotechnical Institute (NGI) and the Norwegian Public Roads Administration (NPRA) in 1967.
References
In situ geotechnical investigations | Rotary-pressure sounding | [
"Engineering"
] | 138 | [
"Civil engineering",
"Civil engineering stubs"
] |
62,367,764 | https://en.wikipedia.org/wiki/H2BK5ac | H2BK5ac is an epigenetic modification to the DNA packaging protein Histone H2B. It is a mark that indicates the acetylation at the 5th lysine residue of the histone H2B protein. H2BK5ac is involved in maintaining stem cells and colon cancer.
Lysine acetylation and deacetylation
Proteins are typically acetylated on lysine residues and this reaction relies on acetyl-coenzyme A as the acetyl group donor.
In histone acetylation and deacetylation, histone proteins are acetylated and deacetylated on lysine residues in the N-terminal tail as part of gene regulation. Typically, these reactions are catalyzed by enzymes with histone acetyltransferase (HAT) or histone deacetylase (HDAC) activity, although HATs and HDACs can modify the acetylation status of non-histone proteins as well.
The regulation of transcription factors, effector proteins, molecular chaperones, and cytoskeletal proteins by acetylation and deacetylation is a significant post-translational regulatory mechanism These regulatory mechanisms are analogous to phosphorylation and dephosphorylation by the action of kinases and phosphatases. Not only can the acetylation state of a protein modify its activity but there has been recent suggestion that this post-translational modification may also crosstalk with phosphorylation, methylation, ubiquitination, sumoylation, and others for dynamic control of cellular signaling.
In the field of epigenetics, histone acetylation (and deacetylation) have been shown to be important mechanisms in the regulation of gene transcription. Histones, however, are not the only proteins regulated by posttranslational acetylation.
Nomenclature
H2BK5ac indicates acetylation of lysine 5 on histone H2B protein subunit:
Histone modifications
The genomic DNA of eukaryotic cells is wrapped around special protein molecules known as histones. The complexes formed by the looping of the DNA are known as chromatin. The basic structural unit of chromatin is the nucleosome: this consists of the core octamer of histones (H2A, H2B, H3 and H4) as well as a linker histone and about 180 base pairs of DNA. These core histones are rich in lysine and arginine residues. The carboxyl (C) terminal end of these histones contribute to histone-histone interactions, as well as histone-DNA interactions. The amino (N) terminal charged tails are the site of the post-translational modifications, such as the one seen in H3K36me3.
Epigenetic implications
The post-translational modification of histone tails by either histone modifying complexes or chromatin remodeling complexes are interpreted by the cell and lead to complex, combinatorial transcriptional output. It is thought that a histone code dictates the expression of genes by a complex interaction between the histones in a particular region. The current understanding and interpretation of histones comes from two large scale projects: ENCODE and the Epigenomic roadmap. The purpose of the epigenomic study was to investigate epigenetic changes across the entire genome. This led to chromatin states which define genomic regions by grouping the interactions of different proteins and/or histone modifications together.
Chromatin states were investigated in Drosophila cells by looking at the binding location of proteins in the genome. Use of ChIP-sequencing revealed regions in the genome characterised by different banding. Different developmental stages were profiled in Drosophila as well, an emphasis was placed on histone modification relevance. A look in to the data obtained led to the definition of chromatin states based on histone modifications.
The human genome was annotated with chromatin states. These annotated states can be used as new ways to annotate a genome independently of the underlying genome sequence. This independence from the DNA sequence enforces the epigenetic nature of histone modifications. Chromatin states are also useful in identifying regulatory elements that have no defined sequence, such as enhancers. This additional level of annotation allows for a deeper understanding of cell specific gene regulation.
Trophoblast stem cell epithelial mediation
MAP3K4 controls the activity of CBP histone acetyltransferase which acetylates histones H2A and H2B to maintain the trophoblast stem cell epithelial phenotype.
Trophoblast are cells forming the outer layer of a blastocyst, which provide nutrients to the embryo and develop into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg. or, after gastrulation,
Methods
The histone mark acetylation can be detected in a variety of ways:
1. Chromatin Immunoprecipitation Sequencing (ChIP-sequencing) measures the amount of DNA enrichment once bound to a targeted protein and immunoprecipitated. It results in good optimization and is used in vivo to reveal DNA-protein binding occurring in cells. ChIP-Seq can be used to identify and quantify various DNA fragments for different histone modifications along a genomic region.
2. Micrococcal Nuclease sequencing (MNase-seq) is used to investigate regions that are bound by well positioned nucleosomes. Use of the micrococcal nuclease enzyme is employed to identify nucleosome positioning. Well positioned nucleosomes are seen to have enrichment of sequences.
3. Assay for transposase accessible chromatin sequencing (ATAC-seq) is used to look in to regions that are nucleosome free (open chromatin). It uses hyperactive Tn5 transposon to highlight nucleosome localisation.
See also
Histone code
Histone acetylation
References
Epigenetics
Post-translational modification | H2BK5ac | [
"Chemistry"
] | 1,298 | [
"Post-translational modification",
"Gene expression",
"Biochemical reactions"
] |
62,368,274 | https://en.wikipedia.org/wiki/Martje%20Thalmann | Martje Thalmann, born Saljé, is a German Türmerin (loosely "Tower keeper"). She was appointed to the post at St Lambert's Church, Münster in January 2014, becoming the first woman since 1383 to have held the position. (Earlier relevant records do not survive.) "Türmer" and "Türmerin" are not officially designated job titles in Germany and it has indeed been known for tour guides to adopt the title for themselves. However, Martje Saljé is believed to be one of at least three genuine Türmer or Türmerinen in Germany who are also women. The nature of the duties has changed in recent decades: Martje Saljé's appointment to the St Lambert's post was nevertheless intended to preserve an authentic tradition. (Guided tours are not possible here.)
Traditionally the job involved regular ascents to the top of a high tower in order to look out and warn fellow citizens (by means of a warning horn, bell, flags and/or, after dark, flashing lights) of approaching armies in time of war, and of outbreaks of house fires at any time. At times of intensified fire risk - for instance on windy days in periods of sustained hot dry weather, or in the event of possible firebomb attacks - it became necessary for a permanent watch to be kept from the top of the tower. In many middle European towns, medieval street patterns with their narrow streets endured well into or beyond the twentieth century, and where there is no readily accessible supply of building stone, the principal building material incorporated into most surviving residential and municipal buildings is timber. Many homes were heated with peat which could often nurture simmering internal hotspots for hours after the fire was believed to have finished burning, and then burst into flames after the householders had gone to bed. This translated into intensified levels of fire risk in many towns and cities. Münster's present Türmerin told an interviewer in 2015 that from her "office" at the top of the tall church tower she is still sometimes able to spot house fires and report them to the fire department, although "it does not happen so often" (es "kommt aber nicht allzu oft vor").
Biography
Personal
Martje Saljé was born in Bremen. She spent a large part of her childhood living in Norway. While she was growing up the family also lived for a time in Canada. Gunther Salje, her father worked as professor of film and theatre. She tells interviewers that even as a small child she had an appetite for performing, mastering a range of instruments including piano, guitar, Double bass, flute, renaissance lute, accordion and 'cello. While she was growing up, membership of the local church community provided ample opportunity for helping to shape the music in the church, performing in bands and, beyond the musical scene, for engaging in youth work more broadly. After leaving school she studied History and Music at the University of Oldenburg. She retains a powerful addiction to music, consciously fixing her own settings and improvisations on the "rules" identified and codified by Bach: "Music used to be how I supported myself: today it is my hobby". She has performed on international tours in France, Belgium, Italy, Britain and Poland: she has worked with rock groups, dance troupes and jazz ensembles.
After leaving university she worked in museums and archive departments and in teaching. She also continued to support herself as an itinerant musician. Her application to take over the post of Türmerin (loosely "Tower keeper") was one of forty-six. Her fellow applicants included six other women. This is despite the fact that the post is a public-sector part-time position without the statutory notice period applicable to full-time positions, and involves extensive night-time and weekend working. Saljé therefore combines the post with a second, more conventional part-time position as a worker with the local Sparda-Bank: "something completely different, involving computers" ("Etwas ganz anderes, was mit Computern").
Notwithstanding her robustly ebullient manner, Martje Saljé is deeply religious. Religion drives much of her commitment to her work as "Türmerin". Despite being a Protestant, she has no issues with the fact that she undertakes her responsibilities in the tower of a Catholic church, and she makes no secret of feeling "a bit closer to Heaven" ("...dem Himmel ein Stück näher...") in her little office high above the city streets. There is also more than a hint of vocation in her reaction when asked how long she intends to continue with her work as Türmerin: "My predecessor carried on till his seventieth year. I might carry on for even longer if my joints hold out".
Professional "Türmerin" duties
Saljé's daily duties begin each day (except on Tuesdays, which are silent) at 20.30, with a walk up the 300 steps to her little office 75 meters up in the church tower. The climb takes her past the base of the flag pole that emerges at the top of the tower, past the three suspended cages that were used to display the tortured corpses of anabaptist rebels after the suppression 1535 rebellion, and past the so-called "council and fire bells" ("Rats- und Brandglocke") which normally, these days, are sounded only for mayoral elections. The office is nevertheless positioned 25 meters below the tip of the spire that tops off the church tower. It is a narrow room, about the size of a typical student room. It contains a desk and a desk-chair along with a separate chair and a bookcase. On one of the walls are photographs of other towers, some of which Martje Saljé has visited. There is also a photograph of Tinkabell and of Cocomau Miez de la Katz. These are the two cats with whom she shares her home '"...although really I'm a dog person").
Her first task each evening, still a little breathless from climbing up the tower, is to telephone the fire station to confirm that she is stationed for her shift in the tower. Every half hour between 21.00 and midnight she sounds the "tower horn" three times, facing in succession south, west and north. She does not sound the horn towards the east, because in that direction there used to be a large cemetery and, by tradition, it is not part of her responsibility to disturb the souls of the dead. An alternative explanation involves a rich and powerful man who used to live to the east of the tower and did not wish to be disturbed. In former times the horn was sounded regularly through the night between 22.00 and 06.00. The present instrument is made of copper and dates from 1950: it is based on a sixteenth century design. The tone resembles the blast from a ships horn, sounding a low C.
Those regular steady horn blasts traditionally reassure the citizens of Münster that they are facing neither an imminent fire in the city nor the approach of enemies from beyond the (imaginary) city walls. The number of the blasts represents the time. At 21.00 there are nine blasts, with a brief pause after each batch of three. At 22.00 there are ten blasts, with a brief pause after the first two batches of three, followed by a third batch of four blasts. ("One has to breathe whilst blowing the horn! 2 Tootings are easy, 3 ooookay, 4 dang! any longer and the Tuermerin might feel somewhat giddy".) The same pattern is followed till Midnight (twelve blasts in four batches of three) after which, in modern times, the citizens can spend the rest of the night undisturbed by Martje Saljé's "tower horn". Interviewed in May 2015, after just fifteen months in the job, Martje Saljé was able to report that she had already spotted several fire outbreaks while on watch. Under these circumstances her first duty is to telephone the fire station to alert them to as many details as she can determine from her vantage point. After that she takes up her "tower horn". Instead of the steady long blasts she uses to communicate the time, she communicates the emergency with an urgent succession of staccato notes.
There is nevertheless very much more to Martje Saljé's approach to her job as "Türmerin" than enjoying the view out of her office window and blowing her horn at half hourly intervals during the latter part of the evening. She sees herself as a principal point of contact between the city of Münster and people all over the world: "Through my own blog [from my office in the tower] to the outside world I publicise the city's traditions ... I enter into real-time dialogue with other people and win for Münster and for St Lambert's the interest of a completely new target group". But she stresses that her employment is not with the church, but with the city. She also operates a Facebook page from the tower. In terms of gaining the attention of target groups, she is not unaware of the extra attention she gains by being both the first woman and the first inveterate blogger in more than six centuries to have served as Türmerin.
She also sees herself as an advocate and representative for the tower, taking part in media interviews and presentations, and performing in charity events on behalf of the church or the city. She has opinions on many topics and is happy to share most of them. Discussions recently arose as to whether it was entirely seemly that the church tower should be used to exhibit to passers-by the three cages that were used to display the tortured corpses of anabaptist rebels in the sixteenth century. The history graduate had views to express: "They are part of the city's history, and it would be disingenuous to remove them. You cannot explain everything through the prism of twenty-first century norms. They must stay there to generate discussions and support opinions. Münster can handle that!". She also turns her hand to researching aspects of city history and joining in with website maintenance and development. Even for Saljé, however, there are topics on which she keeps her own counsel. In 2015 she rejected an interviewer's attempt to extract from her an opinion on the current (in 2019) chancellor: "As Türmerin of the city of Münster, thanks to the neutrality requirement I am not permitted to talk about politics. But I pay very close attention to what goes on in the world, in Europe and in Germany".
Notes
References
People from Bremen (city)
People from Münster
Emergency population warning systems
Fire prevention
1980 births
Living people | Martje Thalmann | [
"Technology"
] | 2,217 | [
"Warning systems",
"Emergency population warning systems"
] |
62,369,482 | https://en.wikipedia.org/wiki/Jean%20Lannes%20%28mathematician%29 | Jean E. Lannes (born 21 September 1947 in Pauligne) is a French mathematician, specializing in algebraic topology and homotopy theory.
Lannes completed his secondary studies at the Lycée Louis-le-Grand in Paris and graduated in 1966 from the École Normale Supérieure. He received his doctorate in 1975 from the University of Paris-Saclay (Paris 12). Afterwards he was a professor there and at the Paris Diderot University (Paris 7). In 2009 he became a professor at the École polytechnique and Directeur des recherches at the Centre de mathématiques Laurent-Schwartz (CMLS); he is now professor emeritus. He was a visiting scholar at several academic institutions, including the Institute for Advanced Study (1979/80) and the Massachusetts Institute of Technology (MIT).
Lannes is known for his research on the homotopy theory of classifying spaces of groups. He proved in the mid-1980s the generalized Sullivan conjecture (which was also proven independently by Gunnar Carlsson and Haynes Miller). The mod p cohomology of the classifying spaces of certain finite groups (elementary Abelian p-groups, for which the generalized Sullivan conjecture was formulated) played an important role in the proof. The connection between the cohomology theory of these finite groups and the classifying spaces of groups is illuminated by the work of Lannes. He introduced the -functor on the category of unstable algebra over the Steenrod algebra. Lannes thus led an important development of algebraic topology in the 1980s. He has collaborated extensively with Lionel Schwartz, Hans-Werner Henn, and Saîd Zarati.
Lannes has also done research on the knot invariants of Vassiliev.
He was an invited speaker at the International Congress of Mathematicians (ICM) in Zurich in 1994. His doctoral candidates include Fabien Morel. In 2007 there was a conference in Djerba in honor of Lannes's 60th birthday.
Selected publications
with Lionel Schwartz: Online
Cohomology of groups and function spaces, Preprint 1986 (not published)
Sur la cohomologie modulo des -groupes abeliennes elementaire, Proc. Durham Symposium 1985, Cambridge University Press 1987
with Saîd Zarati: Sur les U-injectifs, Annales Scient. ENS, vol. 19, 1986, pp. 303–333, Online
with H. W. Henn and L. Schwartz: Localizations of unstable A-modules and equivariant mod p cohomology. Mathematische Annalen, 301(1), 1995 23-68.
with Jean Barge: Suites de Sturm, indice de Maslov et périodicité de Bott, Birkhäuser 2008
with Gaëtan Chenevier : Automorphic Forms and Even Unimodular Lattices, Springer 2019
References
External links
1947 births
Living people
20th-century French mathematicians
21st-century French mathematicians
Lycée Louis-le-Grand alumni
École Normale Supérieure alumni
Academic staff of Paris-Saclay University
Academic staff of École Polytechnique
Topologists | Jean Lannes (mathematician) | [
"Mathematics"
] | 644 | [
"Topologists",
"Topology"
] |
62,369,753 | https://en.wikipedia.org/wiki/Howgills%2C%20Letchworth%20Garden%20City | Howgills in Letchworth Garden City, Hertfordshire, England, is a Grade II listed building on the Register of Historic England in use as a Meeting House for the Society of Friends (Quakers).
Howgills was built on South View in 1907 to a free-style Arts and Crafts design by Robert Bennett (1878–1956) and Benjamin Wilson Bidwell (1877–1944), typical with this firm of architects, although it is thought the design is mostly by Bidwell, a Quaker himself. Associates of Parker & Unwin who were closely connected with the Garden City Movement, Bennett and Bidwell opened an office in Letchworth in 1907 and over the next thirty years went on to design many distinctive buildings in the town. The construction was undertaken by local builders Palmer & Ray. The Meeting House with its large, galleried wood-panelled central meeting room is based on Briggflatts in Cumbria and was named after the Howgill Fells that surround that hall. The building is of two storeys with an irregular façade of three bays with a projecting entrance in the centre bay with a gable roof. The brick chimneys stacks are tall with moulded caps, while the stack on the front façade has weathered offsets. The walls have a roughcast surface while the casement windows with leaded lights sit within stone surrounds. The entrance arch is recessed and has boarded double-doors. The carved timber inscriptions over the entrance hall and meeting room fireplaces are apparently early work by Eric Gill. The decorative copper plaque in the porch is in the Art Nouveau style and reads: "THIS BUILDING ERECTED 1907 IS THE GIFT OF JULIET RECKITT TO THE SOCIETY OF FRIENDS".
One of Letchworth Garden City’s most distinguished and unique early buildings, Howgills was commissioned by Juliet E. Reckitt, the philanthropic niece of the Hull industrialist Sir James Reckitt; she had moved to Letchworth in its early days and allowed the local Society of Friends (Quakers) to meet in the large Meeting Room in the building. In 1913 she donated Howgills to the Quakers while maintaining a flat for herself within the building. In 1934 she also helped with finance when the Society of Friends decided to purchase the freehold.
The horror writer W. F. Harvey was a member of the congregation. His funeral service was held at Howgills before his burial in the churchyard of St Mary the Virgin in Old Letchworth.
Howgills has been a Grade II listed building on the Register of Historic England since 1979.
References
External links
Letchworth Quaker Meeting - Quakers in Britain database
Letchworth Quaker Meeting - Hertford and Hitchin Area Meeting of the Religious Society of Friends (Quakers)
Friends Meeting House, Howgills, South View, Letchworth Garden City - Hertfordshire Churches in Photographs
Grade II listed buildings in Hertfordshire
Letchworth
Buildings and structures in Letchworth
Architectural history
Architecture in England
1907 establishments in England
Quaker meeting houses in England
Grade II listed churches in Hertfordshire
Churches completed in 1907
20th-century Quaker meeting houses | Howgills, Letchworth Garden City | [
"Engineering"
] | 618 | [
"Architectural history",
"Architecture"
] |
62,371,082 | https://en.wikipedia.org/wiki/Tom%20Thumb%20Tempest | "Tom Thumb Tempest" is the 22nd episode of Stingray, a British Supermarionation television series created by Gerry and Sylvia Anderson and produced by their company AP Films (APF) for ITC Entertainment. Written by Alan Fennell and directed by Alan Pattillo, it was first broadcast on 28 February 1965 on the Anglia, ATV London, Grampian and Southern franchises of the ITV network. It subsequently aired on ATV Midlands on 3 March 1965.
The series follows the missions of the World Aquanaut Security Patrol (WASP), an organisation responsible for policing the Earth's oceans in the 2060s. Headquartered at the self-contained city of Marineville on the West Coast of North America, the WASP operates a fleet of vessels led by Stingray: a combat submarine crewed by Captain Troy Tempest, Lieutenant "Phones" and Marina, a mute young woman from under the sea. Stingrays adventures bring it into contact with undersea civilisations – some friendly, others hostile – as well as mysterious natural phenomena. The WASP's most powerful enemy is King Titan, ruler of the ocean floor city of Titanica.
In "Tom Thumb Tempest", Troy has a nightmare in which Stingray and its crew are miniaturised. The use of life-sized sets to convey the shrinking of the puppet characters has drawn a mixed response from commentators. Fennell later authored a picture book based on the episode titled Stingray: Terror of the Giants (1993, Boxtree Ltd).
Plot
The Stingray crew are relaxing in the Marineville standby lounge when Commander Shore tells them to prepare to launch, warning them of a dangerous mission. Captain Troy Tempest is eager to leave immediately but Shore says to await further instructions. Troy's attention turns to the fish in the lounge aquarium. He then falls asleep in his chair.
Troy wakes to hear Shore on the intercom, ordering the crew to launch. He departs in Stingray with Lieutenant "Phones" and Marina. Shore radios in, ordering Troy to pilot Stingray through an undersea tunnel. Troy asks for details of the mission and is left feeling belittled when Shore gruffly denies his request.
Stingray exits the tunnel and collides with a sheet of glass. The crew are astonished to find that they have been miniaturised and ended up inside an aquarium within a giant dining room. Leaving Stingray on their personal hovercraft, they investigate the dining table, which has been laid out for various undersea villains. At the head of the table – set for Titan – is a schematic of Marineville's defence systems. The crew realise that they have stumbled across a gathering of the undersea races to plot the destruction of Marineville.
The crew take cover when an Aquaphibian dressed as a butler enters the room to check the table. They then use a nearby telephone to call Marineville. Shore answers and Troy attempts to explain the situation, but Shore thinks that it is a prank call and hangs up. The crew are again forced to hide when the Aquaphibian returns with Titan's agent X-2-Zero, who notices the mess the crew have made and reprimands the Aquaphibian for what he assumes to be poor table-setting. The Aquaphibian tidies up and leaves.
The crew destroy the schematic by soaking it in alcohol and setting it alight. The fire quickly engulfs the room, forcing them back to Stingray. As the aquarium boils, Troy realises that Stingray is trapped. He orders Phones to launch a torpedo to shatter the glass, hoping that the escaping water will put out the fire.
As Phones fires the torpedo, Troy wakes to find himself back in the Marineville lounge. Shore tells the crew to stand down and Troy, realising that he has had a nightmare, apologises to Shore for his earlier impatience.
Regular voice cast
Ray Barrett as Commander Shore
Robert Easton as Lieutenant "Phones" and Surface Agent X-2-Zero
Don Mason as Captain Troy Tempest
Production
The title of the episode was based on the folklore character Tom Thumb. In the script, the Aquaphibian butler was called "Jeevesea" – a pun on the fictional valet Jeeves.
"Tom Thumb Tempest" was significant for combining Stingrays -scale Supermarionation puppets with a life-sized dining room set. (Accordingly, at one point Troy says that the contents of the room appear to be "three times" larger than normal.) It was not the first episode of an APF series to deal with miniaturised characters: the idea had previously been explored in Supercars "Calling Charlie Queen" and Fireball XL5s "The Triads". However, while those episodes had used back projection for their miniaturisation effects, "Tom Thumb Tempest" placed "shrunken" characters on a physical set. Stephen La Rivière cites "Tom Thumb Tempest" as another example of the "Land of Giants-type" episode that APF had attempted in its previous two series.
Reception
Gerry Anderson biographers Simon Archer and Marcus Hearn consider "Tom Thumb Tempest" to be one of Stingrays most entertaining episodes. By contrast, TV Zone names it the worst of the series, calling the ending "reasonably clever" but the overall episode a "wasted opportunity". The magazine argues that the episode is spoiled through its use of "two hoary old clichés – the 'incredible shrinking cast' idea ... and the 'it was all a dream' cop-out ending" – the first of which merely emphasises the "unreality" of the plot while the second renders the episode "entirely inconsequential". It also criticises the dream sequence itself for being insufficiently surreal and "[degenerating] into sub-Tom and Jerry shenanigans" towards the end.
Jim Sangster and Paul Condon, authors of Collins Telly Guide, describe the episode as "decidedly less aimed at realism" than those of later Supermarionation series. They also refer to dream sequences in general as "one of Anderson's most annoying recurring plot devices".
La Rivière suggests that the "tantalising glimpse of reality" in this episode conflicted with APF's ongoing efforts to make its puppet characters seem more human. Ian Fryer regards the episode as a precursor of the final Supermarionation series, The Secret Service, which featured both puppets and live actors.
References
Works cited
External links
1965 British television episodes
Fiction about size change
Science fiction television episodes
Stingray (1964 TV series)
Television episodes about nightmares
Television episodes set on fictional islands | Tom Thumb Tempest | [
"Physics",
"Mathematics"
] | 1,357 | [
"Fiction about size change",
"Quantity",
"Physical quantities",
"Size"
] |
62,371,798 | https://en.wikipedia.org/wiki/Sanford%20Consortium | The Sanford Consortium is a non-profit biomedical research institute in La Jolla, California. It was formed from a collaboration between the Burnham Biomedical Research Institute, Salk Institute for Biological Studies, Scripps Research, La Jolla Institute for Immunology, and the University of California, San Diego. The institute was previously known as the Sanford Consortium for Regenerative Medicine (SCRM).
The 'consortium' research building is 136,700 square-feet. It is located on a 7.5-acre property nearby to and leased from UC San Diego. The development and construction of the building and facilities from 2007 through 2011 cost $106,572,300 in construction and $21,028,500 in equipment acquisition costs.
References
Medical research institutes in California
Cancer organizations based in the United States
Stem cell research
La Jolla, San Diego
Medical and health organizations based in California
Independent research institutes | Sanford Consortium | [
"Chemistry",
"Biology"
] | 184 | [
"Translational medicine",
"Tissue engineering",
"Stem cell research"
] |
62,371,957 | https://en.wikipedia.org/wiki/Estradiol%20distearate | Estradiol distearate (EDS), also known as estradiol dioctadecanoate, is an estrogen and an estrogen ester, which was never marketed. It is a long-acting prodrug of estradiol in the body.
See also
Estradiol dienantate
List of estrogen esters § Estradiol esters
References
Abandoned drugs
Estradiol esters
Stearate esters | Estradiol distearate | [
"Chemistry"
] | 92 | [
"Drug safety",
"Abandoned drugs"
] |
62,373,559 | https://en.wikipedia.org/wiki/Adolescent%20sleep | Adolescent sleep is typically poor in duration and quality. Sleep duration and quality reduce to suboptimal levels, and sleep duration variability and latency increases during adolescence. Sleep recommendations suggest that adolescents should obtain 8–10 hours of sleep per night. Additionally, there is a shift in the body's circadian rhythm such that sleep and wake timings become later during adolescence. Technology, social factors, and physical development are thought to contribute to poor sleep during this time. Poor sleep duration and quality in adolescents has been linked with altered brain functioning and development, poor mental and physical health, as well as higher rates of disease and mortality. The concerns surrounding poor sleep during adolescence has garnered significant public attention, especially concerning policies related to school start times. Many evidences suggest that sleep contributes positively to attention, behavior, and academic achievement for adolescents.
Developmental changes
Adolescent sleep worsens with age. Specifically, longitudinal research demonstrates that sleep duration shortens during the transition from high school to college. Additionally, sleep efficiency (the amount of time spent asleep when in bed) decreased during this transition. Day-to-day variability in sleep duration increased during this transition, suggesting that adolescent sleep duration becomes less stable with time. A variety of social, physical, biological, and psychological factors change during adolescence which contributes to declines in sleep. In particular, puberty has been explored as a contributor to changes in adolescent sleep. Luteinizing hormone (LH) is secreted during sleep at the onset of pubertal maturation, pointing to an important relationship between sleep and pubertal development.
Sleep recommendations
The National Sleep Foundation recommends that teenagers (14–17 years) obtain 8 to 10 hours of sleep. Their recommendation further stipulates that less than 7 hours and more than 11 hours of sleep may be harmful. Additionally, it is recommended that young adults (18–25 years) obtain 7 to 9 hours of sleep and avoid sleep less than 6 hours and more than 11 hours.
Adolescent sleep researchers have conducted studies to provide stronger empirical evidence for sleep recommendations. Fuligni and colleagues (2019) examined a sample of American adolescents and found that younger adolescents, especially those with elevated levels of internalizing symptoms, need more sleep in order to experience optimum levels of positive mood the next day. Additionally, another study examining Mexican-American youth found that roughly 7.5 hours of sleep was predictive of high GPA but 8.75 hours of sleep was predictive of lower internalizing symptoms. This finding suggests that optimal sleep duration differs depending on the outcome.
More research is needed to understand individual differences in sleep duration during adolescence.
Sleep duration
Sleep duration has been declining since the early 90s according to research. Evidence also suggests that teen females, ethnic minorities, and those of low socioeconomic status experience the lowest durations. Puberty is thought to contribute to poor sleep during adolescence as teens undergo physical and social maturation. For adolescents, this inclination is demonstrated by their tendency to stay up later and sleep longer, particularly on holidays or weekends. A burgeoning area of adolescent sleep research is focused on understanding the contribution of technology-use to poor teen sleep. Importantly, research shows that declines in adolescent sleep duration are characteristic of adolescents around the world. The consequences of poor extend far beyond mere fatigue, leading to various physical, cognitive, and mental health issues.
Brain
Poor sleep duration has been found to be related to altered brain development during adolescence. Telzer and colleagues (2015) found that teens with greater day-to-day variability in their sleep duration had lower white matter integrity one year later. This result remained when controlling for sleep duration, which suggests that sleep variability may be more consequential for teen brain development than simply duration. Another study found that sleep duration was strongly associated with gray matter volume of the bilateral hippocampus among a sample of healthy children and adolescents.
Risk-taking
Poor sleep duration and increased risk-taking has been a well-established association in the adolescent sleep literature. A recent meta-analysis reported that poor sleep duration results in a 1.43 times greater odds of engaging in risky behaviors. The direction of the relationship between risk-taking and sleep duration is still unknown, thus causal claims cannot be made.
Emotion
A plethora of research shows that low sleep duration is linked with poor mood. Furthermore, youth who report low sleep duration also demonstrate difficulties with emotion regulation. This is of particular concern because adolescents experience fluctuations in mood as a result of pubertal maturation, however, poor sleep duration worsens mood and regulation abilities rendering these adolescents vulnerable.
Sleep quality
Empirical evidence suggests that sleep quality is poor during adolescence. Poor sleep quality during adolescence has been linked with a variety of negative behaviors and outcomes. For instance, poor sleep quality has been shown to be positive associated with anxiety and depressive symptoms among teens. A study published in 2016 found that sleep quality significantly mediated the relationship between age and depressive symptoms, suggesting that the rise in depressive symptoms during adolescence is partly explained by poor sleep quality. A long line of research has also demonstrated that poor sleep quality is associated with increased risk-taking behaviors among teens. Neuroscience research (fMRI) has found that poor sleep quality is associated with greater risk-taking on a behavioral task. This risky behavior was further associated with decreased activity in cognitive control regions of the brain and increased activity in reward regions of the brain. Moreover, poor sleep quality has been found to be linked with dampened intra-network connectivity of regions in the Default Mode Network, a brain network that undergoes development during adolescence.
Technology
There has been an increased interest in understanding the relationship between sleep and technology use among adolescents. In the era of social media, there is a growing concern for blue-light emitted by technology may be interfering with adolescents' ability to obtain restful and sufficient sleep. Use of technologies (i.e. television, cell phone, computer/laptop) is associated with prolonged sleep duration (the amount of time it takes to fall asleep) and shorter sleep duration among teenagers. Television use was associated with the poorest sleep duration. Adolescent technology-use has also been linked with excessive daytime sleepiness and caffeine consumption, suggesting that technology-use may interfere with sleep and may lead to increased caffeine consumption. Longitudinal data demonstrates that time spent using technology is predictive of short sleep duration, however short sleep duration was also predictive of time spent using technology. More longitudinal research with larger sample sizes is needed to clarify the mechanisms underlying the association between technology-use and sleep during adolescence.
Chronotype
Adolescence is characterized by an evening chronotype preference with adolescents engaging in late bed and wake times. An evening chronotype is unique to the period of adolescence compared to childhood and adulthood which are characterized by a morning chronotype. Eveningness during adolescence is linked with increased substance use, worse overall mood, poor diet, increased depressive symptoms, increased anxiety symptoms, and poor emotion regulation. Beyond conveying bed and wake times, chronotype is also indicative of optimal times of functioning. For instance, researchers tested adolescents on their executive functioning performance at two times: once at a time that is optimal for chronotype (i.e. evening for evening chronotypes vs. morning for morning chronotypes) and once at a time that is suboptimal for chronotype (i.e. morning for evening chronotypes vs. evening for morning chronotypes). They found that morning adolescents tested in the morning performed better than in the evening, and evening chronotype adolescents tested in the evening performed better than in the morning.
Sleep measures
Pittsburg Sleep Quality Index
The Pittsburgh Sleep Quality Index (PSQI) is a well-validated and widely used self-report questionnaire that measures sleep quality. Nineteen items are combined to create seven component scores of sleep, and those component scores are then used to create an overall “global score” of sleep quality. The seven components consist of subjective sleep quality, sleep disturbances, sleep duration, sleep latency, habitual sleep efficiency, use of sleep medications, and daytime dysfunction. The PSQI has a high internal reliability (Cronbach's alpha = 0.83). The PSQI has been used in many studies assessing adolescent sleep quality.
Actigraphy
Actigraph watches are commonly used to gather objective measures of sleep. The watch is worn on the non-dominant wrist and measures sleep using body movement. Data gathered from the watch includes sleep duration, number of awakenings, total minutes of nighttime awakenings, and latency.
Morningness Eveningness Questionnaire (MEQ)
The first valid and reliable measure of chronotype was created by Horne and Östberg (1976): Morningness-Eveningness Questionnaire (MEQ) contains 19 items tapping sleep and wake time preferences. Sample items include “Assuming adequate environmental conditions, how easy do you find getting up in the mornings?” and “Considering your own ‘feeling best’ rhythm, at what time would you get up if you were entirely free to plan your day?”. The questionnaire consists of both Likert and timescale items, and items are scored to obtain a composite score. Since its creation, the MEQ has been validated in some adolescent and young adult samples. Early assessments of this questionnaire's psychometric properties revealed that the scale has good internal consistency (a = .82).
References
Sleep physiology | Adolescent sleep | [
"Biology"
] | 1,906 | [
"Behavior",
"Sleep physiology",
"Sleep"
] |
62,374,018 | https://en.wikipedia.org/wiki/3-Methyl-PCPy | 3-Methyl-PCPy (3-Me-PCPy) is an arylcyclohexylamine derivative with an unusual spectrum of pharmacological effects, acting as both a potent NMDA antagonist and also a triple reuptake inhibitor which inhibits reuptake of all three monoamine neurotransmitters serotonin, dopamine and noradrenaline. It also acts as a high affinity sigma receptor ligand, selective for the σ2 subtype. It produces both stimulant and dissociative effects in animal behavioural studies.
Legal Status
3-Methyl-PCPy is covered by drug analogue laws in various jurisdictions (UK, Germany, Japan, Australia etc.) as a generic arylcyclohexylamine derivative, and a structural isomer of phencyclidine.
See also
3-Methyl-PCP
BTCP
Deoxymethoxetamine
Ephenidine
MDPCP
References
Arylcyclohexylamines
NMDA receptor antagonists
Serotonin–norepinephrine–dopamine reuptake inhibitors
Dissociative drugs | 3-Methyl-PCPy | [
"Chemistry"
] | 236 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
62,374,983 | https://en.wikipedia.org/wiki/NGC%203749 | NGC 3749 is a spiral galaxy located in the constellation of Centaurus at an approximate distance of 130.52 million light-years. NGC 3749 was discovered in 1835 by John Herschel.
References
External links
NGC 3749 on SIMBAD
Spiral galaxies
Centaurus
3749
Astronomical objects discovered in 1835
035861 | NGC 3749 | [
"Astronomy"
] | 65 | [
"Centaurus",
"Constellations"
] |
62,375,030 | https://en.wikipedia.org/wiki/Non-catalytic%20tyrosine-phosphorylated%20receptor | Non-catalytic tyrosine-phosphorylated receptors (NTRs), also called immunoreceptors or Src-family kinase-dependent receptors, are a group of cell surface receptors expressed by leukocytes that are important for cell migration and the recognition of abnormal cells or structures and the initiation of an immune response. These transmembrane receptors are not grouped into the NTR family based on sequence homology, but because they share a conserved signalling pathway utilizing the same signalling motifs. A signaling cascade is initiated when the receptors bind their respective ligand resulting in cell activation. For that tyrosine residues in the cytoplasmic tail of the receptors have to be phosphorylated, hence the receptors are referred to as tyrosine-phosphorylated receptors. They are called non-catalytic receptors, as the receptors have no intrinsic tyrosine kinase activity and cannot phosphorylate their own tyrosine residues. Phosphorylation is mediated by additionally recruited kinases. A prominent member of this receptor family is the T-cell receptor.
Features and Classification
Members of the Non-catalytic tyrosine-phosphorylated receptor family share a couple of common features.
The most prominent feature is the presence of conserved signalling motifs containing tyrosine residue, such as Immunoreceptor tyrosine-based activation motifs (ITAMs), in the cytoplasmic tail of the receptors. The receptor signaling pathway is initiated by ligand binding to the extracellular domains of the receptor. Upon binding, the tyrosine residues in the signaling motifs are phosphorylated by membrane-associated tyrosine kinases. The receptors themselves have no intrinsic tyrosine kinase activity. The phosphorylated NTRs, in turn, initiate a specific intracellular signaling cascades. The signaling cascade is down-regulated by dephosphorylation by protein tyrosine phosphatases. Additional characteristics of the receptor family are a rather small (< 20 nm) extracellular domain and the binding to ligands that are anchored to solid surfaces or membranes of other cells. NTRs are exclusively expressed in leukocytes.
Based on those features, about 100 distinct NTRs have been identified. The table below lists different classes of NTRs. Members of a class have a high sequence homology and typically share the same gene locus.
Structure
NTRs are transmembrane glycoproteins with typically small ectodomains of 6 to 10 nm. NTRs have either an N-terminal or C terminal ectodomains. Ectodomains have a high sequence diversity between members. Many NTRs have an unstructured intracellular domain which contains tyrosine residues that can be phosphorylated by tyrosine kinases. Some receptors in this family, however, lack a cytoplasmic tail and therefore associate with adaptor proteins containing the same tyrosine residues.
Adaptor proteins associate to their respective NTR through their transmembrane helixes carrying oppositely charged residues.
The cytoplasmic domains do not contain any intrinsic tyrosine kinase activity.
Conserved tyrosine-containing motifs
Tyrosine residues of NTRs mostly appear in conserved amino acid motifs with defined sequence signatures that define whether the receptor plays an activator or inhibiting role in the cell. These motifs allow binding of proteins containing a SH2 domain. Motifs are intrinsic or in the associated adaptor subunits.
Immunoreceptor tyrosine-based activation motifs (ITAMs) are short amino acid sequences that contain two tyrosine residues (Y) arranged as Yxx(L/I)x6-8Yxx(L/I), where L and I indicate Leucine or Isoleucine residue respectively (according to amino acid abbreviations), x denotes any amino acids, a subscribe 6-8 indicates a sequence of 6 to 8 amino acids in length. ITAMs recruits activating kinases to the NTR. Inhibitory signals are transduced by Immunoreceptor tyrosine-based inhibitory motifs (ITIMs) of the signature (S/I/V/L)xYxx(I/V/L), bind to cytoplasmic tyrosine phosphatases. Immunoreceptor Tyrosine-based Switch Motifs (ITSMs) with the signature TxYxx(I/V) may induce both activator and inhibitory signals. These motifs are confined to SLAM family receptors.
Finally, Immunoglobulin Tail Tyrosine Motifs (ITTMs) with a YxNM signature have been found to have a costimulatory effect.
Signalling Pathway
Biophysics of receptor-ligand binding
The signalling pathway of an NTR is induced upon binding to its respective ligand.
NTRs, as they are defined, have a short ectodomain (5 - 10 nm) and bind to surface-anchored ligands. For binding to take place, the membrane of the leukocyte has to come into close proximity to the surface with the ligand. The receptor-ligand complex, once bound, spans a dimension of about 10-16 nm. Ectodomains of other surface molecules can be much larger (up to 50 nm), therefore the membrane has to bend towards the ligand, which introduces tension within the membrane. Additionally, large pulling forces can act on the complex, changing dissociation rates of the complex.
Receptor triggering
NTR triggering, the initial step of the NTR signalling pathway, involves phosphorylation of the tyrosine residues in the cytoplasmic domain of the receptor or the associated adaptor protein. Once phosphorylated, these residues recruit further signalling proteins.
Phosphorylation of the tyrosine residues is performed by membrane-anchored Src family kinases (SFK) (e.g. Lck, Fyn, Lyn, Blk), while receptor protein tyrosine phosphatases (RPTP) (e.g. CD45, CD148) mediate the dephosphorylation of the same residues. SFK and RPTP are constitutively active. In an untriggered state, the activity of phosphatases dominates, keeping NTRs in an unphosphorylated state, and thus preventing signal initiation. It has been shown that inhibition of tyrosine phosphatases induces phosphorylation in NTRs and signalling even without ligand binding. It is therefore assumed that a perturbation of SFK and RPTP balance due to ligand binding, leading to stronger kinase activity and hence accumulation of phosphorylated tyrosine residues, is needed for initiation of downstream signalling.
Different mechanisms of how the balance is disturbed upon ligand binding have been suggested.
The induced proximity or aggregation model suggests that upon receptor-ligand binding multiple receptors aggregate. SFKs have multiple phosphorylation sites that regulate their catalytic activity. If the kinase is associated with an NTR, aggregation brings two or more SFK into close proximity, which allows them to phosphorylate each other. Hence due to receptor aggregation, SFKs are activated leading to higher kinase activity and increased NTR phosphorylation. Evidence for this model is given by mathematical models and an experiment where artificially cross-linking NTRs led to signal induction. However, there is not sufficient evidence that receptor aggregation happens in vivo.
According to the Conformational change model, binding of a ligand induces a conformational change in the receptor such that the cytosolic domain becomes accessible for kinases. Thus phosphorylation is only possible when the receptor is bound to a ligand. However, structural studies have failed to show conformational changes.
The Kinetic segregation model proposes that RPTPs are physically excluded from NTR-ligand-binding regions. Ectodomains of RPTPs are much larger compared to NTRs and SFKs. The interaction between ligand and receptor brings the membranes into close contact, and the gap between membranes is too narrow for membrane proteins with large ectodomains to diffuse into the region. This increase the ratio of SFKs over RPTPs in the region surrounding the receptor-ligand complex. Any non-bound NTR would diffuse out of these regions too quickly to induce a downstream signal. Evidence for this model is given by the observation that in T cells, phosphatases CD45 and CD148 segregate from the T-cell receptor upon ligand binding. It was also shown that truncation of phosphatase ectodomains as well as the elongation of ligand ectodomains reduces the segregation and inhibits NTR triggering. Similar findings have been reported for Receptors, CD28 family receptors, Dectin-1.
Downstream signaling pathway
Phosphorylated tyrosine residues in cytoplasmic tails of NTRs serve as docking sites for SH2 domains of cytosolic signalling proteins. Once bound to the NTR they are activated by phosphorylation and can propagate the signal. Whether a receptor acts as an inhibitor or activator depends on the conserved tyrosine-containing motifs present in its cytoplasmic domain.
Activatory motifs (ITAMs) bind kinases, such as Syk family kinases (e.g. ZAP70 for T-cell receptor) that phosphorylate a range of substrates, thereby inducing a signalling cascade leading to the activation of the leukocyte. Inhibitory motifs (ITIM) on the other hand recruit the cytoplasmic tyrosine phosphates SHP1, SHP2 and the phosphatidylinositol phosphatase SHIP-1. The phosphatases can attenuate the signal by dephosphorylating a broad range of signalling molecules.
Signal integration from multiple NTRs
At any given time, multiple NTR types can be engaged with their receptive ligands, inducing activatory, costimulatory as well as inhibitory signals. The functional response of the leukocytes depends on the integration of the signals.
References
Receptors
Immune system
Immune receptors
Transmembrane proteins
Leukocytes
Cell signaling | Non-catalytic tyrosine-phosphorylated receptor | [
"Chemistry",
"Biology"
] | 2,132 | [
"Organ systems",
"Receptors",
"Immune system",
"Signal transduction"
] |
62,375,099 | https://en.wikipedia.org/wiki/Tangut%20numerals | Tangut numerals are words and characters used to denote numbers in the Tangut language during the Western Xia regime (1038–1227) and during the subsequent Yuan dynasty (1271–1368).
Tangut numerals are written in the same format as Chinese numerals. There is an ordinary set of digits that is used for writing numbers within Tangut text (for example, chapter numbers and dates) in manuscripts and printed books, as well as for engraving on monumental inscriptions on stone. There are also two additional sets of number characters used for special purposes. Page numbers in printed books dating from the Western Xia period and the Yuan dynasty are often written using Chinese numerals.
The latest surviving example of Tangut numerals occur on the Tangut dharani pillars which were erected in Baoding on the 10th month of the 15th year of the Hongzhi era of the Ming dynasty, which corresponds to 1502.
Cardinal numbers
The characters used to write ordinary cardinal numbers are listed below. There are two different words for "ten": *gha is the normal word, but *sha is sometimes used, especially for the number of days in dates, e.g. (gha lhi sha ny) "10th day of the 10th month".
Multiple-digit numbers are constructed using a similar method to that for Chinese and Japanese numerals.
Ordinal numbers
Ordinal numbers are formed by adding the suffix *tsew to the cardinal number, for example (so tsew) "third" and (ny gha tsew) "twentieth". The word (phu tsew) may be used for "first", although (lew tsew) is also found.
Fractions
The character *khwy is used for one half. For more complex fractions, the formula "n [parts] out of d parts" is used, where n is the numerator and d is the denominator, and the denominator is specified first. This corresponds to the structure for fractions in Chinese, for example Tangut (so pha kha lew) "one third" corresponds to Chinese 三分之一 (sān fēn zhī yī) "one third".
Special numbers
In addition to the normal set of cardinal numbers, there is an additional set of characters used for the numbers 2 through 7 in some circumstances. These numbers are only used in a few certain words, as well as in special month names that are used in a Tangut ode entitled Poem on Pleasure of Every Month. Ksenia Kepping considers this and other odes in the same collection (dated 1185) to be written in a special ritual language, using vocabulary which is not normally used in the common Tangut language.
There is also a special set of filiation characters for the numbers 2 through 8 which are used exclusively to indicate the relative seniority of sons, where the number is followed by the word *ew "son". The numbers from 2 to 7 are phonetically identical (2, 4, 6, 7) or phonetically very close (3, 5) to the corresponding ritual numbers used in the Poem on Pleasure of Every Month, but the character for 8 is phonetically identical to the normal character for 8.
Unlike the ordinary Tangut numbers, which are closely cognate to the numbers used in other Tibeto-Burman languages such as Tibetan and Nuosu, the ritual and filiation numbers do not appear to be related to numbers in any other language. Moreover, the characters for 4 and 7 are homophones in both the ritual and filiation series, which is implausible for a spoken language.
The ritual numbers are used in the following words, which are all related to Buddhism or astrology:
(zhu lo) "two fish" (i.e. pisces)
(rer u) "three storehouses" (i.e. the tripiṭaka)
(ngwyr ka) "four stringed-instrument" (i.e. the pipa)
(chyr nir ngyr) "Five Platforms Mountain" (i.e. the Western Xia equivalent of the sacred Mount Wutai, which was located in the Helan Mountains)
(ngwyr ngewr) "seven sounds" (i.e. seven claps of thunder or bursts of music)
Dates
Tangut numbers are used to denote the year, month and day in date expressions.
A number followed by the character *kew "year" indicates the year of the specified era, for example (tshwu wu gha chhiw kew) means the 16th year of the Qianyou era (i.e. 1185).
Lunar months are designated as a number followed by *lhi "moon, month", except that there are special words for the first and last month. An intercalary month is indicated by putting the character *lhu in front of the month name, for example (lhu rer lhi) "intercalary 12th month). There are also special month names used in the ritual language of the Poem on Pleasure of Every Month.
A number followed by the character *ny "day" indicates the day of the month, for example (sha lhi sha gy ny) "19th day of the 7th month".
See also
Tangut people
Tangut script
Tangut language
Footnotes
References
Numerals
Tangut script | Tangut numerals | [
"Mathematics"
] | 1,119 | [
"Numeral systems",
"Numerals"
] |
62,375,361 | https://en.wikipedia.org/wiki/Frontiers%20of%20Biogeography | Frontiers of Biogeography is a peer-reviewed open access scientific journal publishing biogeographical science, with the academic standards expected of a journal operated by and for an academic society. It published on behalf of the International Biogeographical Society, using the eScholarship Publishing platform. The current editor-in-chief is Robert J. Whittaker.
Abstracting and indexing
The journal is abstracted and indexed in:
References
External links
Open access journals
Ecology journals
Geography journals
Biogeography
Academic journals established in 2009
English-language journals | Frontiers of Biogeography | [
"Biology",
"Environmental_science"
] | 113 | [
"Environmental science journals",
"Biogeography",
"Ecology journals",
"Environmental science journal stubs"
] |
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