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56,104,974 | https://en.wikipedia.org/wiki/Relacorilant | Relacorilant (developmental code name CORT-125134) is an antiglucocorticoid which is under development by Corcept Therapeutics for the treatment of Cushing's syndrome. It is also under development for the treatment of solid tumors and alcoholism. The drug is a nonsteroidal compound and acts as an antagonist of the glucocorticoid receptor. As of December 2017, it is in phase II clinical trials for Cushing's syndrome and phase I/II clinical studies for solid tumors, while the clinical phase for alcoholism is unknown.
References
External links
Relacorilant - AdisInsight
Antiglucocorticoids
Experimental drugs
4-Fluorophenyl compounds
Isoquinolines
Ketones
Pyrazoles
Pyridines
Sulfonamides
Trifluoromethyl compounds | Relacorilant | [
"Chemistry"
] | 177 | [
"Ketones",
"Functional groups"
] |
56,105,123 | https://en.wikipedia.org/wiki/IONIS-GCCRRx | {{DISPLAYTITLE:IONIS-GCCRRx}}
IONIS-GCCRRx, also known as ISIS-426115, is an antiglucocorticoid which is under development by Ionis Pharmaceuticals (formerly Isis Pharmaceuticals) for the treatment of diabetes mellitus type 2. It has also been under investigation for the treatment of Cushing's syndrome, but no development has been reported. The drug is an antisense oligonucleotide against the glucocorticoid receptor. As of December 2017, it is in phase II clinical trials for diabetes mellitus type 2.
References
Experimental diabetes drugs
Antiglucocorticoids
Antisense RNA
Drugs with undisclosed chemical structures
Experimental drugs
Therapeutic gene modulation | IONIS-GCCRRx | [
"Biology"
] | 158 | [
"Therapeutic gene modulation"
] |
56,106,124 | https://en.wikipedia.org/wiki/Cell%20isolation | Cell isolation is the process of separating individual living cells from a solid block of tissue or cell suspension. While some types of cell naturally exist in a separated form (for example blood cells), other cell types that are found in solid tissue require specific techniques to separate them into individual cells. This may be performed by using enzymes to digest the proteins that binds these cells together within the extracellular matrix. After the matrix proteins have been digested, cells remain loosely bound together but can be gently separated mechanically. Following isolation, experiments can be performed on these single isolated cells including patch clamp electrophysiology, calcium fluorescence imaging, and immunocytochemistry.
Techniques
Circulating cells
The techniques required to obtain isolated cells vary depending on the cell type required. Circulating cells such as blood cells or some tumour cells can be isolated by taking a blood sample. As blood samples contain a mixture of many different cell types, a method of separating out cells into different types must be used. The most commonly used method for this is flow cytometry, during which an automated analyser inspects a narrow stream of cells. In one version of this technique, a light is shone on the stream of cells, and the analyser detects the reflected light or fluorescence before using this information to rapidly manoeuvre the cells of interest into a collection chamber.
Solid tissues
When dealing with solid tissues, obtaining tissue for cell isolation may be more challenging. Surplus human tissue can sometimes be obtained at the time of planned surgery, for example specimens of right atrial appendage are often excised and discarded during open heart surgery such as coronary artery bypass surgery. Other tissues such as samples of pancreas or bladder may be taken as a biopsy. Alternatively, tissue from animals is frequently obtained by sacrificing the animal.
After a tissue specimen has been obtained, it must be surrounded or perfused by a solution at an appropriate temperature containing the salts and nutrients required to keep the cells alive. This may be performed by simply submerging the tissue in the solution, or may involve more complex arrangements such as Langendorff perfusion. Commonly used solutions included modifications of Tyrode's solution or Krebs and Henseleit's solution These solutions contain precise concentrations of electrolytes including sodium, potassium, calcium, magnesium, phosphate, chloride, and glucose. The concentrations of these electrolytes must be carefully balanced, paying attention to osmotic pressure. The acidity of the solution must be regulated, often using a pH buffer such as HEPES. Isolation of cells from some tissues may be improved by oxygenating the solution. In the initial stages, perfusing the tissue with a solution that does not contain calcium is useful particularly when isolating cardiac myocytes, as the absence of calcium causes separation of the intercalated disks.
Proteolytic enzymes can then be added to the solution. Enzymes that digest collagen (collagenases) are often used when isolating cells from the heart or bladder. General-purpose enzymes that digest many sorts of protein (proteases) may also be used. When isolating cells from brain tissue, other enzymes that break down DNA (DNAases) may be required.
These enzymes, in addition to digesting the extracellular matrix, can also digest other important proteins essential for the cells of interest to function. If cells are exposed to these enzymes for too long then cell death results, but if they are not exposed to the enzymes for long enough then digestion of the extracellular matrix will not be complete. After the enzymes have been removed from the tissue by perfusing it with a second solution that does not contain enzymes, cells can be mechanically separated or dissociated. A simple technique for dissociating cells involves cutting the tissue into small chunk before agitating the chunks in a solution using a pipette.
Uses
Isolated cells can be used to study how cells work, how they change in response to disease, and how they are affected by drugs. An example of an experimental technique which uses isolated cells is patch clamp electrophysiology, used to study how charged particles flow across the cell membrane. Complementary techniques include calcium fluorescence imaging using dyes that emit light in response to calcium to measure how calcium is regulated within the cell, and immunocytochemistry which uses antibodies tagged with a fluorescent marker to identify where proteins are located within a cell. Isolated cells can also be used for cell culture, in which a single cell multiplies to create a colony of cells.
Cell isolation can also be used as part of a treatment. Isolation of pancreatic islet cells, followed by their subsequent culture and transplantation, has been used to treat patients with Type 1 Diabetes.
See also
Cell sorting
References
Further reading
Isolation of Atrial Cardiomyocytes:
Isolation of Ventricular Cardiomyocytes:
Isolation of Pancreatic Islet Cells:
Isolation of Haematopoetic stem cells:
Isolation of Mesenchymal stem cells:
Isolation of Hepatic stellate cells:
Isolation of Circulating tumour cells:
Isolation of Neuroglial cells:
Isolation of Urothelial cells:
Cells
Laboratory techniques | Cell isolation | [
"Chemistry"
] | 1,064 | [
"nan"
] |
56,106,288 | https://en.wikipedia.org/wiki/National%20Prize%20for%20Medicine | The National Prize for Medicine () was created in 2001 by the , the Association of Medical Faculties, the Association of Medical Scientific Societies, and the Medical College of Chile.
It is given to recognize the work of those doctors who have excelled among their peers in the area of clinical or public health and, in addition, have had a prominent role in teaching, academic administration, or research.
The prize consists of a diploma, a commemorative medal, and an amount of money that is contributed by the medical community.
It is awarded every two years.
Winners
2002: Julio Meneghello, surgeon of the University of Chile, pediatrician
2004: , surgeon of the University of Chile, pediatric heart surgeon
2006: , surgeon of the University of Chile, internist and gastroenterologist
2008: , surgeon of the University of Chile, internist
2010: , surgeon of the University of Chile, internist and gastroenterologist
2012: Fernando Mönckeberg Barros, medical surgeon of the University of Chile
2014: , surgeon of the University of Chile, ophthalmologist
2016: Manuel García de los Ríos Álvarez, surgeon of the University of Concepción, internist and diabetologist
2018: Otto Dörr Zegers, psychiatrist of the University of Chile
Notes
See also
List of medicine awards
References
External links
Regulations of the National Prize for Medicine
2001 establishments in Chile
Awards established in 2001
Chilean awards
Medicine in Chile
Medicine awards | National Prize for Medicine | [
"Technology"
] | 286 | [
"Science and technology awards",
"Medicine awards"
] |
56,106,791 | https://en.wikipedia.org/wiki/Noise%20blanker | In the design of radio receivers, a noise blanker is a circuit intended to reduce the effect of certain kinds of radio noise on a received signal. It is often used on broadcast shortwave receivers or communications receivers and some types of two-way radio transceivers. The noise blanker is only effective on impulse-type noise such as from lightning or from automotive ignition systems, and cannot improve performance on wideband continuous background noise, or interfering signals on the same frequency. In cases where there are strong signals on frequencies near to the desired frequency, a noise blanker circuit may be ineffective and may reduce the quality of the received signal.
Implementation
Typically this is a network in the intermediate frequency section of the receiver; when a pulse of noise passes through the IF amplifiers, it is usually of greater amplitude than the desired signal. The noise blanker circuit momentarily reduces the gain of the IF stage during the impulse. More complex noise blankers may use a secondary IF stage and have adjustable threshold and timing characteristics so as to reduce the noise passed through to the audio stages of the receiver.
A noise blanker is best applied before any narrow-bandwidth filters in the signal path, so as not to introduce "ringing" and distortion in the filtered signal. Noise blankers are most useful with amplitude modulation or single sideband signals. Frequency modulation receivers generally include a signal limiter stage which tends to reject noise pulses.
See also
Noise reduction
References
Radio electronics
Receiver (radio) | Noise blanker | [
"Engineering"
] | 295 | [
"Radio electronics",
"Receiver (radio)"
] |
56,107,522 | https://en.wikipedia.org/wiki/RZ%20Piscium | RZ Piscium (or RZ Psc) is a UX Orionis type variable star away, in the constellation Pisces. Over the years, the star has been found to brighten and dim erratically, dimming by as much as a tenth of its usual luminosity. RZ Piscium has been found to emit large amounts of infrared radiation, suggesting the presence of a substantial mass of gas and dust orbiting the star, possibly from a "disrupted planet".
Disrupted planet
Because of the infrared excess and rapid light variations, astronomers conclude that:
According to astronomer Ben Zuckerman:
Observations
In 2017, RZ Piscium was studied using the XMM-Newton satellite, the Shane 3-meter telescope at Lick Observatory in California and the 10-meter Keck I telescope at W. M. Keck Observatory in Hawaii. The temperature of the star was found to be about the same as the Sun (). Further, the star was found to produce about a thousand times more x-rays than the Sun, suggesting that the star is relatively young. On the other hand, RZ Piscium was found to contain a relatively small amount of surface lithium, which suggests the star is between 30 − 50 million years old; this is somewhat "old" for a star with so much circumstellar dust. Most young stars that are as dusty as RZ Piscium may be producing planets, but given its relatively advanced age, RZ Piscium may be destroying and consuming its planets instead.
In 2020, a red dwarf companion with the mass of 0.12 Solar mass was detected with a projected separation of 23 AU from the primary star. The incandescence of the companion star thus make up about one third of excess infrared emission previously attributed to the dust.
See also
List of stars that have unusual dimming periods
References
External links
, star with unusual light fluctuations (21 December 2017).
, a presentation by Tabetha S. Boyajian
, a presentation by Issac Arthur
Pisces (constellation)
Planetary rings
2017 in science
Piscium, RZ
J01094205+2757020
K-type subgiants
Herbig Ae/Be stars | RZ Piscium | [
"Astronomy"
] | 457 | [
"Pisces (constellation)",
"Constellations"
] |
56,109,450 | https://en.wikipedia.org/wiki/Yutaka%20Tokiwa | Yutaka Tokiwa is a Senior Researcher at Okinawa Industrial Technology Center, who has published extensively on the biodegradability of plastics. He has an h-index of 61 according to Google Scholar.
References
Year of birth missing (living people)
Living people
Polymer scientists and engineers | Yutaka Tokiwa | [
"Chemistry",
"Materials_science"
] | 58 | [
"Polymer scientists and engineers",
"Physical chemists",
"Polymer chemistry"
] |
56,110,453 | https://en.wikipedia.org/wiki/Sustainalytics | Sustainalytics is a company that rates the sustainability of listed companies based on their environmental, social and corporate governance (ESG) performance. The company was born of a merger between Toronto-based Jantzi Research, which was founded in 1992 by Sustainalytics' current CEO Michael Jantzi, and its European counterpart. Following its acquisition of GES International on January 9, 2019, Sustainalytics had more than 600 employees with offices in 17 cities around the world and over 700 institutional investor clients. On April 21, 2020, Morningstar, Inc. acquired the remaining ~60% of Sustainalytics' shares to become the sole owner.
Morningstar acquisition
In 2016, Morningstar, Inc. released the first sustainability rating for mutual funds and exchange-traded funds based on Sustainalytics' company ESG research. In 2017, Morningstar, Inc. become a 40% shareholder in the company alongside senior management, Stichting Pensioenfonds Zorg en Welzijn (PGGM), ABN AMRO Group and Renewable Partners On 21 April 2020, Morningstar Inc. completed the acquisition, purchasing the remaining 60% of the shares.
Yahoo! Finance
In 2018, Yahoo! Finance started to include Sustainalytics' ESG score for over 2,000 companies. Retail investors will also be able to see if companies are involved in controversies or controversial products or practices, such as thermal coal and controversial weapons.
Green lending and green bonds
In 2017, ING Group issued the first sustainability improvement loan where the interest rate of the loan is pegged to the sustainability rating of the lender, Koninklijke Philips N.V., as measured by Sustainalytics. Sustainalytics also provides "second opinions" for corporate governmental issuers that assesses the framework of the issuer's green, social or sustainability bond. In 2017 and 2018, investors voted Sustainalyitcs as the "Most Impressive Second Opinion Provider" for this service in the GlobalCapital Sustainable and Responsible Capital Markets Awards 2017.
Emissions scandals
Sustainalytics flagged governance concerns at Volkswagen months before the 2015 Volkswagen emissions scandal. Sustainalytics had also flagged corporate governance concerns at Fiat Automobiles 18 months prior to the company being accused of breaking emissions laws in 104,000 diesel vehicles in January 2017
HBR's 100 best performing CEOs
In 2015, Harvard Business Review started to include Sustainalytics' ESG Rating as part of its assessment of the 100 best performing CEOs in the world.
Indices
In 2000, Sustainalytics launched the Jantzi Social Index, the first socially-screened stock index composed of Canadian companies, and, in 2013, Sustainalytics partnered with the United Nation's Global Compact to launch the Global Compact 100 index, a real-time stock index that tracks Global Compact signatories awarded a high ESG rating by Sustainalytics. On 10 September 2018, the World Bank issued a sustainable development note linked to Sustainalytics' Global Sustainability Signatories Index, another index that tracks United Nations Global Compact signatories with high sustainability ratings. The note will not pay a coupon, but rather return the principle in addition to the positive return of the index.
References
1992 establishments in the Netherlands
Companies based in Amsterdam
Environmentalism
Ethical banking
Ethical investment
Governance
Market data | Sustainalytics | [
"Technology"
] | 669 | [
"Market data",
"Data"
] |
56,111,973 | https://en.wikipedia.org/wiki/Stalin%20and%20the%20Scientists | Stalin and the Scientists: A History of Triumph and Tragedy 1905–1953 is a 2016 popular science non-fiction book on the history of science in the Soviet Union under Joseph Stalin by English novelist and science writer, Simon Ings. It is Ings' second non-fiction book, the first being The Eye: A Natural History (2007). He had previously published eight novels.
Stalin and the Scientists was longlisted for the 2016 Baillie Gifford Prize for Non-Fiction.
Background
Ings' inspiration for Stalin and the Scientists came from Soviet psychologist, Alexander Luria's book Mind of a Mnemonist, about the life of Russian journalist and mnemonist, Solomon Shereshevsky. Ings said in 2016 interviews that Luria is often referred to as the founder of modern neuroanatomy and "the godfather of the literary genre we call popular science". "Luria's account more or less set the template for modern popular science and ... pretty much set me on the path I'm on now." Ings had considered writing a biography about Luria, but felt that while Luria's achievements were "extraordinary", considering the climate of political repression he worked in, Ings was concerned that Western readers would consider his career too ordinary, and would miss the context in which it unfolded. Ings' passion for popular science and the need to explain the context within which Luria and other Soviet scientists worked, changed what would have been a one-year "modest biography" into a "five-year behemoth" that "burned through three editors" and, Ings added, "nearly killed me".
Ings said, as a novelist, he was "absurdly under-qualified" to tackle a book like Stalin and the Scientists, but added that only a novelist could be so "ridiculously ambitious" and "naive enough to stick his or her neck out so far". Ings felt that given the kind of science prevalent in Russia at the time, perhaps this "really has to be the job of a novelist rather than a historian". Responding to statements that this is "the first history" of Soviet science, Ings said, "Certainly no-one's been foolish enough to attempt to tell the whole story of science under Stalin in a single volume, but be assured I didn't dig this entire thing single-handed from virgin ground."
Reception
In a review in The Guardian, David Holloway described Stalin and the Scientists as a "fascinating story" that reveals "the tragedy and the triumph" of Soviet science. He called it a "lively book" and complimented Ings on his "clear and simple" scientific explanations, and the way he highlighted the personalities of those involved: the "brilliant scientists", the "charlatans", the "visionaries" and the "careerists". A reviewer of the book in Publishers Weekly complimented Ings on the sensitive way in which he exposed the lives of the scientists and their experiences, and how he "ably documents the challenges, failures, and achievements of Soviet science". The reviewer commented that while Ings "can be long-winded", he "engagingly fuses history, science, and storytelling".
British historian and author Simon Sebag Montefiore wrote in The New York Times that Ings "skillfully" portrays the lives of the scientists of this period. He called Ings "an entertaining storyteller who often captures the essence of things", and described the book as "lively and interesting" and full of "priceless nuggets and a cast of frauds, crackpots and tyrants". Montefiore added, however, that while Ings highlights the failures of Soviet science, he omits its successes, for example the Tupolev and MiG airplanes, and the T-34 tank. Montefiore was also critical of errors in the book, for example Stalin's birthday and Felix Dzerzhinsky's tenure as head of Cheka, the Soviet secret police.
Writing in Socialist Review, John Parrington was also critical of flaws and omissions. While he described the book as "ambitious in scope", and called it "fascinating" and "important", Parrington said it is not without "elementary errors", like Ings' statement that "the Bolsheviks ... and the Mensheviks ... missed the 1905 revolution". Parrington also complained that Ings does not explain what it was that "destroyed the hopes and dreams" of Russian scientists in the 1920s when Stalin came to power.
American science historian Loren Graham also criticised errors and omissions in the book. In a review in The Wall Street Journal, he said Ings is "a gifted writer", and called Stalin and the Scientists "a good single source" for readers new to Soviet science. But Graham felt that one of the book's shortcomings was that Ings only focuses on topics that interest him, like biology, physiology and psychology, while giving little attention to mathematics and theoretical physics. Graham also noted several "incorrect or exaggerated" statements in the book, for example: Alexei Gastev was a "leading architect of Russia's industrialisation programme"; Nikolai Bernstein "invented cybernetics"; and Stalin was "the last in a long line of European philosopher kings". Graham concluded that the book is the result of "an impressive amount of study" and "deserves attention", but "a very critical form of attention".
According to the review aggregator Book Marks, Stalin and the Scientists received "positive" reviews, based on 4 reviews.
References
Cited works
2016 non-fiction books
English non-fiction books
Popular science books
Books about scientists
Books about Joseph Stalin
Science and technology in the Soviet Union
Persecution of intellectuals in the Soviet Union
History of science
Faber & Faber books | Stalin and the Scientists | [
"Technology"
] | 1,197 | [
"History of science",
"History of science and technology"
] |
56,112,052 | https://en.wikipedia.org/wiki/Blink%20Home | Blink is an American home automation company which produces home security cameras. The company was founded in 2009 by Peter Besen, Don Shulsinger, Dan Grunberg, Stephen Gordon, and Doug Chin. The company was initially started as Immedia Semiconductor Inc in 2009, but pivoted into a consumer electronics company. In July 2014, the company had a Kickstarter campaign for their indoor security camera, which raised over US$1 million. Subsequently, Blink later announced an outdoor security camera, home security system, and video doorbell.
Amazon announced in December 2017 that they had acquired the company. Immedia Semiconductor, LLC continues to operate as an independent subsidiary. It is anticipated that Blink's technology will be used for the Amazon Key service.
In December 2019, Amazon rolled out patches in response to research citing vulnerabilities in the Blink XT2 security camera systems found by vulnerability detection firm Tenable.
Most Blink products are made in China, while others are made in Malaysia by IoT Manufacturing Sdn Bhd.
Products
Blink Video Doorbell
The blink video doorbell is a wirelessly connected smart device that allows video and audio to be viewed via another device. It works similarly to the Ring doorbell, including in its ability to connect to Amazon Alexa and an offering of a "plus" subscription, which allows greater cloud storage capacity and syncing of multiple devices.
Blink Dog Camera
The Blink Dog Camera is a smart device designed to provide pet owners with a method of monitoring their pets when the owners are not at home. The camera contains high-definition 1080p video and night vision capabilities.
References
Blink Home
Home automation companies
American companies established in 2009
Companies based in Essex County, Massachusetts
Amazon (company) acquisitions
Kickstarter-funded products
2017 mergers and acquisitions
Andover, Massachusetts | Blink Home | [
"Technology"
] | 358 | [
"Home automation",
"Home automation companies"
] |
56,112,213 | https://en.wikipedia.org/wiki/Central%20Idaho%20Dark%20Sky%20Reserve | The Central Idaho Dark Sky Reserve is a dark-sky preserve near the Sawtooth National Recreation Area, in the U.S. state of Idaho. It was designated on December 18, 2017, and is the first gold-tier dark sky preserve in the United States. The area was designated by International Dark-Sky Association. The area includes the city of Ketchum, Idaho which was separately designated a "Dark Sky Community" in 2017. Idaho State Highway 75 in the Sawtooth Valley between Redfish Lake and Pettit Lake roughly traverses the reserve's "core areas". Several sky quality meters are installed along State Highway 75 in this area.
Local communities and federal authorities collaborated in the designation; the governments will take measures such as shielding street lights to preserve the area's dark sky; Ketchum has had a dark sky ordinance since 1999, and Sun Valley, also in the reserve, has its own local ordinance. The U.S. Forest Service, which manages much of the land in the area, will post informational signs about the dark sky reserve, and has said it will reduce light pollution from its buildings; compliance by individuals on Forest Service land will be voluntary.
Another dark sky certification effort was under way in 2017 about away at Bruneau Dunes State Park, which hosts a public astronomical observatory.
References
External links
2017 establishments in Idaho
Dark-sky preserves in the United States
Protected areas of Idaho
Protected areas of Blaine County, Idaho
Protected areas of Custer County, Idaho
Protected areas of Elmore County, Idaho
International Dark Sky Reserves | Central Idaho Dark Sky Reserve | [
"Astronomy"
] | 315 | [
"International Dark Sky Reserves",
"Dark-sky preserves in the United States",
"Dark-sky preserves"
] |
56,113,038 | https://en.wikipedia.org/wiki/Fugue%20Machine | Fugue Machine is a music sequencer created by San Francisco composer and software developer Alexander Randon, also known by his stage name as Alexandernaut. Marketed as the "world’s first multi-playhead piano roll," Fugue Machine allows the user to sequence a melody and have up to three variations of it play all at the same time. The application was originally released on October 8, 2015 for iOS, and quickly garnered notability for its intuitive methods of making complex pieces and for being the first app to be developed from the "Cultural Incubator" program by the Gray Area Foundation for the Arts.
Summary
Fugue Machine is a "multi-playhead" sequencer where the user creates a melody sequence for four playheads to perform at different tempos, directions, and pitches. The melody is programmed by two-finger panning, which allows the user to change the position of multiple notes, and three-finger panning which alters the velocity and length of MIDI notes. The melody can last for up to eight measures.
There are seven parameters that control the performance of the playheads: "style," which determines the direction of the playhead including forward, reverse, forward-reverse, and reverse-forward, tempo, which determines how fast or slow the playhead moves in relation to the "master tempo," "start," which determines when a playhead begins moving, "invert switch," which inverts the pitches of the notes from the melody, "octave," which changes the pitch of the entire melody by whole octaves, "pitch," which changes the pitch of the melody by single notes, and "velocity," how loud the playhead performs the notes. Fugue Machine allows for the easy creation of polyrhythmic music by having the "tempo" parameters be in multiplied or divided numbers, such as a playhead being performed eight times slower than the "master tempo" when set at ÷8. The app also has a "shift slider" that moves the pitches of all the playheads up and down. Up to 128 pieces can be saved in Fugue Machine.
Development
Randon studied the works of Johann Sebastian Bach, a composer who popularized the fugue compositional technique, while in college. He became obsessed with how fugue involved using mathematical operations, something that would later become a major part of his compositions. In applying math in his works, Randon, composing in a digital audio workstation, would have to copy and paste a melody he sequenced and manually program variations of it in different pitches, speeds, and directions, which took a very long time to do. This give Randon the idea of developing a machine that could compose variations of a single theme automatically. He explained, "I was a main-track engineering student, so the idea of combining something I was good at (math) to something I wanted to be good at (music), seemed obvious." Randon spent years programming multiple drafts of Fugue Machine, but failed due to problems of coming up with a proper user interface. Randon then decided, out of desperation, to focus on the back end of the program first: "I quickly realized that the most eloquent technical design was to have one music sequence being read multiple times. Then it hit me: That's a piano roll with multiple playheads! I seriously jumped up and down, alone in my music studio, for far too long." This became the basis for making the final product of Fugue Machines, which took eight months to program.
Randon made Fugue Machine as part of a program fostered by the Gray Area Foundation for the Arts named "Cultural Incubator", where participants are committed to develop an app that combines elements of art and technology to impact society.
Fugue Machine became the first application to be produced as part of Cultural Incubator. The most complicated part of programming the application was coding the "Note On" messages it sends to external synthesizers when one note is being played simultaneously by more than one playhead. Randon had to do this since many external synthesizers vary in terms of how they handle more than one message performing the same note at the same time: some make a second voice perform the second message or replace the first one, and some even crash.
Reception and release
On October 8, 2015, Alexandernaut released Fugue Machine for iOS and a fourteen-track album entitled Songs for Fugue Machine he made using the app. The application quickly gained significant attention from both users and publication in only a few months due to its easy method of making intricate compositions. As CDM stated, "It’s really what melodic sequencers in the computer age ought to be – not primitive imitations of what you can do with melodies, but accessible automatons, treating the melody as fluidly as it appears on a displays."
Journalist Francis Preve described the program as "innovative" and "instantly addictive," praising its interactivity (in particular its shift slider), its external MIDI feature, and the variety of complex musical styles and "ethereal textures" that could be produced intuitively which ranged from "ambient to cinematic to trance-like." The application garnered an "App of the week" review from Stuff magazine, where writer Craig Grannell labeled it "a superb iPad music app, up there with the very best." His only criticisms were that the controls were a "bit fiddly" and it lacked in the number of available save slots.
Notable uses
Electronica producer Max Cooper used Fugue Machine in making his extended play Chromos (2017).
References
External links
Alexandernaut official website
"Fugue Machine" at the official Alexandernaut website
Music sequencers
IOS software
Digital audio workstation software
IPad
MIDI
2015 software | Fugue Machine | [
"Engineering"
] | 1,179 | [
"Music sequencers",
"Automation"
] |
56,113,127 | https://en.wikipedia.org/wiki/Regional%20planning%20organization | A Regional Planning Organization is a government body that guides the development of public and private resources in a manner that ensures public safety, well being and livability. Regional planning organizations take different forms and may also include a metropolitan planning organization or may be part of a multi-state or multi-government association. A regional planning organization develops plans that coordinate planning by groups of local governments and special districts that have common social, political, economic, cultural or other similarities. Generally this process takes the form of urban planning or one of its sub-disciplines such as land use planning, transportation planning, or environmental planning.
Regional planning organizations exist in a variety of different formats. In some areas they are a part of another organizations such as a Regional Council of Governments. Regional planning organizations are sometimes also called regional development organisations as the need for planning often includes key economic development issues.
See also
Metropolitan planning organization
Regional Planning Councils (RPCs), a quasi-governmental body established by the state of Florida
Regional Development Commissions (RDC), a regional government in the state of Minnesota
Urban planning
Regional planning
External links
National Association of Development Organizations
References
Urban planning
Regional science | Regional planning organization | [
"Engineering"
] | 230 | [
"Urban planning",
"Architecture"
] |
56,113,766 | https://en.wikipedia.org/wiki/Caldimicrobium | Caldimicrobium is a genus of bacteria from the family of Thermodesulfobacteriaceae.
Caldimicrobium is an anaerobic thermophile which is roughly 1.0–1.2 micrometers long and 0.5 micrometers wide.
See also
List of bacterial orders
List of bacteria genera
References
Further reading
Thermodesulfobacteriota
Bacteria genera | Caldimicrobium | [
"Biology"
] | 88 | [
"Bacteria stubs",
"Bacteria"
] |
56,114,444 | https://en.wikipedia.org/wiki/Chandrasekhar%20polarization | Chandrasekhar Polarization is a partial polarization of emergent radiation at the limb of rapidly rotating early-type stars or binary star system with purely electron-scattering atmosphere, named after the Indian American astrophysicist Subrahmanyan Chandrasekhar, who first predicted its existence theoretically in 1946.
Chandrasekhar published a series of 26 papers in The Astrophysical Journal titled On the Radiative Equilibrium of a Stellar Atmosphere from 1944 to 1948. In the 10th paper, he predicted that the purely electron stellar atmosphere emits a polarized light using Thomson law of scattering. The theory predicted that 11 percent polarization could be observed at maximum. But when this is applied to a spherical star, the net polarization effect was found to be zero, because of the spherical symmetry. But it took another 20 years to explain under what conditions this polarization can be observed. J. Patrick Harrington and George W. Collins, II showed that this symmetry is broken if we consider a rapidly rotating star (or a binary star system), in which the star is not exactly spherical, but slightly oblate due to extreme rotation (or tidal distortion in the case of binary system). The symmetry is also broken in eclipsing binary star system.
Discovery
Attempts made to predict this polarization effect were initially unsuccessful, but rather led to the prediction of interstellar polarization. In 1983, scientists found the first evidence of this polarization effect on the star Algol, an eclipsing binary-star system.
The polarization on rapidly rotating star was not found until 2017 since it required a high-precision polarimeter. In September 2017, a team of scientists from Australia observed this polarization on the star Regulus, which rotates at 96.5 percent of its critical angular velocity for breakup.
See also
Polarization in astronomy
References
Polarization (waves)
Astrophysics | Chandrasekhar polarization | [
"Physics",
"Astronomy"
] | 376 | [
"Astronomical sub-disciplines",
"Polarization (waves)",
"Astrophysics"
] |
56,115,043 | https://en.wikipedia.org/wiki/Chandrasekhar%E2%80%93Kendall%20function | Chandrasekhar–Kendall functions are the eigenfunctions of the curl operator derived by Subrahmanyan Chandrasekhar and P. C. Kendall in 1957 while attempting to solve the force-free magnetic fields. The functions were independently derived by both, and the two decided to publish their findings in the same paper.
If the force-free magnetic field equation is written as , where is the magnetic field and is the force-free parameter, with the assumption of divergence free field, , then the most general solution for the axisymmetric case is
where is a unit vector and the scalar function satisfies the Helmholtz equation, i.e.,
The same equation also appears in Beltrami flows from fluid dynamics where, the vorticity vector is parallel to the velocity vector, i.e., .
Derivation
Taking curl of the equation and using this same equation, we get
.
In the vector identity , we can set since it is solenoidal, which leads to a vector Helmholtz equation,
.
Every solution of above equation is not the solution of original equation, but the converse is true. If is a scalar function which satisfies the equation
, then the three linearly independent solutions of the vector Helmholtz equation are given by
where is a fixed unit vector. Since , it can be found that . But this is same as the original equation, therefore , where is the poloidal field and is the toroidal field. Thus, substituting in , we get the most general solution as
Cylindrical polar coordinates
Taking the unit vector in the direction, i.e., , with a periodicity in the direction with vanishing boundary conditions at , the solution is given by
where is the Bessel function, , the integers and is determined by the boundary condition The eigenvalues for has to be dealt separately.
Since here , we can think of direction to be toroidal and direction to be poloidal, consistent with the convention.
See also
Poloidal–toroidal decomposition
Woltjer's theorem
References
Astrophysics
Plasma theory and modeling | Chandrasekhar–Kendall function | [
"Physics",
"Astronomy"
] | 423 | [
"Plasma theory and modeling",
"Astronomical sub-disciplines",
"Astrophysics",
"Plasma physics"
] |
56,116,830 | https://en.wikipedia.org/wiki/Year-riddle | The year-riddle is one of the most widespread, and apparently most ancient, international riddle-types in Eurasia. This type of riddle is first attested in Vedic tradition thought to originate in the second millennium BCE.
Research
Studies have surveyed the exceptionally wide attestation of this riddle type. The riddle is conventionally thought to been eastern in origin, though this may simply reflect the early date of writing in the east. A variety of guiding metaphors appear in the Year-riddle, and it can be helpful to analyse its variants on these lines. It has been argued that 'versions usually express the conventional tropes of a given culture or society and indicate regional sources'.
Year-riddles are numbered 984, 1037 and 1038 in Archer Taylor's English Riddles from Oral Tradition. As a folktale motif, the riddle is motif H721 in the classificatory system established by Stith Thompson's Motif-Index of Folk-Literature.
Examples
Most year-riddles are guided by one (or more) of four metaphors: wheels, trees, animals (particularly human families), and artefacts (particularly architecture).
The first three all make an appearance in the year-riddle that appears in several versions of the Tale of Ahikar. This story seems to have originated in Aramaic around the late seventh or early sixth century BCE. The relevant passage is lost from the earliest surviving versions, but the following instance, from a later Syriac version, is thought likely to represent the early form of the text:
[The king] said to me, “Aḥiḳar, expound to me this riddle: A pillar has on its head twelve cedars; in every cedar there are thirty wheels, and in every wheel two cables, one white and one black.” And I answered and said to him, “(...) The pillar of which thou hast spoken to me is the year: the twelve cedars are the twelve months of the year; the thirty wheels are the thirty days of the month; the two cables, one white and one black, are the day and the night.
Wheels and wheeled vehicles
Ancient Indian sources afford the earliest attestations of the year-riddle: examples in the Rigveda are thought to originate c. 1500×1200 BCE. Their use of metaphors of wheels reflects the prominence of the concept of the wheel of time in Asian culture.
Hymn 164 of the first book of the Rigveda can be understood to comprise a series of riddles or enigmas. Many are now obscure, but may have been an enigmatic exposition of the pravargya ritual. Rigveda 1.164.11 runs:
Devanagari
Latin transliteration
Modern English translation
With twelve spokes—for it does not become old—
the wheel of the truthful order turns on and on around the sky.
Sons, in pairs, o Agni,
seven hundred and twenty, are standing.
Meanwhile, 1.164.48 gives:
Devanagari
Latin transliteration
Modern English translation
The felly-pieces are twelve, the wheel is one,
the nave-pieces three; who has understood this?
On it are placed, as it were, 360
pegs that do not wobble.
Likewise, in the Mahabharata, the riddles posed to Ashtavakra by King Janaka in the third book begin with the year-riddle: what has six naves, twelve axles, twenty-four joints, and three hundred and sixty spokes?
A later Indic example using a similar metaphor is from the riddles ascribed to Amir Khusrau (1253–1325):
Here the three hundred and fifty-five days of the year correspond to the twelve lunar cycles of the Islamic calendar year.
Trees and other plants
A large number of variants (numbered 1037-38 in Archer Taylor's English Riddles from Oral Tradition) compare the year to a tree; indeed, 'riddlers rarely use the scene of a tree and its branches for other subjects than the year and the months or the sun and its rays'. The tree is also the metaphor usually found in Arabic folktales. The popularity of tree-imagery is thought to echo the widespread popularity of trees as a metaphor for the world or life in Eurasian traditions.
Most year-riddles of this kind can be thought of as containing some or all of the following components:
Versions containing only parts of the tree occur across Eurasia, whereas the versions with the nests occur only in Europe.
Examples include this verse from the early eleventh-century Shahnameh:
What are the dozen cypresses erect
In all their bravery and loveliness,
Each one of them with thirty boughs bedeckt--
In Persia never more and never less?.
To which Zāl responds
First as to those twelve cypresses which rear
Themselves, with thirty boughs upon each tree:
They are the twelve new moons of every years,
Like new-made monarchs, throned in majesty.
Upon the thirtieth day its course is done
For each; thus our revolving periods run.
Later examples include:
Yonder stands a tree of honor,
twelve limbs grow upon her,
every limb a different name.
It would take a wise man to tell you the same. [English]
A tree with twelve branches and thirty leaves, of which fifteen are black and fifteen white, strewn with open flowers of whitish yellow [Malay]
There stands a tree with twelve branches, on each branch are four nests, in each nest are six young, and the seventh is the mother. [Lithuanian]
More elaborate variations on this theme are also found. One Icelandic example is preserved in three early-modern manuscripts of the riddle-contest in the medieval Heiðreks saga and runs: ('what is that assembly which has twelve flowers, and in each flower are four nests? And in each nest are seven birds and each has its own name? How are they guessed? 12 months, 4 weeks, 7 days').
Animals
Human families
Human families provide a guiding metaphor for a number of year riddles (numbered 984 in Archer Taylor's English Riddles from Oral Tradition), though almost never in English-language tradition. Although only first attested in the roughly tenth-century CE Greek Anthology, the following Greek riddle is there ascribed to Cleobulus (fl. C6 BCE); even if it is not that ancient, the attribution to him would suggest that the riddle was thought of in Ancient Greek culture as itself being very old:
Another example of the family metaphor is this French riddle, first published in 1811:
The only English-language example of this kind of year-riddle found by Taylor was from Saba Island in the Antilles: ''. — 'Twelve months of the year, de second one February'.
Other animals
Eastern Europe and Asia exhibit a range of other animal metaphors for the year, usually involving a team of twelve oxen pulling one plough or gatherings of different species of birds.
Artefacts
A number of year-riddles use man-made objects as their controlling metaphor. For example, a modern Greek riddle invokes a cask made with twelve staves, and a Parsi riddle the contents of a chest. But most often these riddles draw on architecture, as in the following mid-twentieth-century example from central Myanmar:
Ein-daw-thar-lan:
set-nhit khan:
ta khan: thone gyait
ah phay eit
phwiṇ hlet ta gar:
lay: paut htar:
win bu twet bu bar yẹ lar:
Hnit
It is a beautiful house with twelve rooms and thirty people can sleep in each room. There are four doors left open. Have you ever passed through these doors?
A year.
References
Riddles
Chronology | Year-riddle | [
"Physics"
] | 1,597 | [
"Spacetime",
"Chronology",
"Physical quantities",
"Time"
] |
53,247,133 | https://en.wikipedia.org/wiki/European%20Lead%20Factory | The European Lead Factory is a public-private partnership that aims to accelerate early drug discovery in Europe. The European Lead Factory is funded by the Innovative Medicines Initiative and consists of a pan-European consortium that includes 7 pharmaceutical companies as well as partners from academia and small and medium-sized enterprises (SMEs).
Drug discovery platform
The European Lead Factory is operational since 2013 and consists of two main components: the Joint European Compound Library and the European Screening Centre. Together these elements provide a platform for pharmaceutical researchers in Europe to identify drug discovery starting points, by connecting innovative drug targets to high-quality small molecules. The result is defined in a ‘hit list’: a number of compounds that show affinity for the target. The compounds on those lists can either be used as probes to better understand biological pathways or as starting points for lead discovery efforts for novel drugs. These hits can be further optimised outside of the European Lead Factory, for affinity but also for drug-like properties as selectivity, solubility and metabolism in the human body. The ultimate goal is that these candidate drugs will solve unmet medical needs when fully approved as drug by the authorities.
Open innovation
The Joint European Compound Library has a collection of around 500,000 chemical compounds selected from private company collections and complemented by the novel molecules synthesised by the European Lead Factory chemistry partners. European researchers from academia as well as SMEs and patient organisations submit their biological target to be screened against the compound collection by the European Lead Factory researchers by means of industrial standard high-throughput screening.
References
2013 establishments in Europe
Biology in Europe
Consortia in Europe
Crowdsourcing
Drug discovery companies
Research projects | European Lead Factory | [
"Chemistry"
] | 334 | [
"Drug discovery companies",
"Drug discovery"
] |
53,248,722 | https://en.wikipedia.org/wiki/NGC%206801 | NGC 6801 is a spiral galaxy in the constellation of Cygnus. It was discovered by Lewis A. Swift on August 5, 1886.
Supernovae
In May 2011 a Type Ia supernova, 2011df, was detected in NGC 6801. 2015af, a Type II supernova was discovered in August 2015.
References
Unbarred spiral galaxies
Cygnus (constellation)
6801
08981
50063 | NGC 6801 | [
"Astronomy"
] | 88 | [
"Cygnus (constellation)",
"Constellations"
] |
53,249,097 | https://en.wikipedia.org/wiki/Rachel%20Davidson | Rachel A. Davidson is an American civil engineer and professor in the Disaster Research Center at the University of Delaware.
She is known for her research on natural disaster risk modeling, disaster risk management and civil infrastructure systems. She is a winner of the Dorothy Swanson Excellence in Teaching Award and a nominee for the Walter L. Huber Civil Engineering Research Prize.
She was the president of Society for Risk Analysis (2010-2011).
See also
Fire safety
References
External links
Rachel A. Davidson at University of Delaware
American civil engineers
American structural engineers
Living people
Stanford University alumni
Princeton University alumni
University of Delaware faculty
Year of birth missing (living people) | Rachel Davidson | [
"Engineering"
] | 128 | [
"Civil engineering",
"Civil engineering stubs"
] |
53,249,961 | https://en.wikipedia.org/wiki/Fileless%20malware | Fileless malware is a variant of computer related malicious software that exists exclusively as a computer memory-based artifact i.e. in RAM. It does not write any part of its activity to the computer's hard drive, thus increasing its ability to evade antivirus software that incorporate file-based whitelisting, signature detection, hardware verification, pattern-analysis, time-stamping, etc., and leaving very little evidence that could be used by digital forensic investigators to identify illegitimate activity. Malware of this type is designed to work in memory, so its existence on the system lasts only until the system is rebooted.
Definition
Fileless malware is sometimes considered synonymous with in-memory malware as both perform their core functionalities without writing data to disk during the lifetime of their operation. This has led some commentators to claim that this variant strain is nothing new and simply a “redefinition of the well-known term, memory resident virus”, whose pedigree can be traced back to the 1980s with the birth of the Lehigh Virus that was developed by the originator of the term, Fred Cohen, and became influential with his paper on the topic.
This synonymy is however incorrect. Although the aforementioned behavioral execution environment is the same, in both cases i.e. both malware variants are executed in system memory, the crucial differentiation is the method of inception and prolongation. Most malware's infection vector involves some writing to the hard disk, in order for it to be executed, whose origin could take the form of an infected file attachment, external media device e.g. USB, peripheral, mobile phone etc., browser drive-by, side-channel etc.
Each of the aforementioned methods has to have contact with the host system's hard drive, in some form or another, meaning that even when employing the stealthiest anti-forensic methods, some form of the infected residue will be left on the host media.
Fileless malware on the other hand, from the point of inception until process termination (usually by way of a system reboot), aims never to have its contents written to disk. Its purpose is to reside in volatile system areas such as the system registry, in-memory processes and service areas.
Fileless malware commonly employs the Living off the Land (LotL) technique which refers to the use of pre-existing operating system binaries to perform tasks. The goal of this technique is to avoid unnecessarily dropping extra malware on the system to perform tasks that can be done using already existing resources, this aids in stealth, primarily because the pre-existing system binaries are commonly signed and trusted. An example is an attacker using PsExec to connect to a target system.
History
Fileless malware is an evolutionary strain of malicious software that has taken on a steady model of self-improvement/enhancement with a drive towards clearly defined focused attack scenarios, whose roots can be traced back to the terminate-and-stay-resident viral programs that, once they were launched, would reside in memory awaiting a system interrupt before gaining access to their control flow; examples of which were seen in viruses such as Frodo, The Dark Avenger, Number of the Beast.
These techniques evolved by way of temporary memory resident viruses and were seen in famous examples such as: Anthrax, Monxla and took on their truer fileless nature by way of in-memory injected network viruses/worms such as CodeRed and Slammer.
More modern evolutionary incarnations have been seen in viruses such as Stuxnet, Duqu, Poweliks, and Phasebot.
Recent developments
On February 8, 2017, Kaspersky Lab's Global Research & Analysis Team published a report titled: "Fileless attacks against enterprise networks" which implicates variants of this type of malware, and its latest incarnations, affecting 140 enterprise networks across the globe with banks, telecommunication companies and government organizations being the top targets.
The report details how a variant of fileless malware is using PowerShell scripts (located within the Microsoft Windows Registry system) to launch an attack against a target's machine leveraging a common attack framework called Metasploit with supporting attack tools such as Mimikatz, and leveraging standard Windows utilities such as ‘SC’ and ‘NETSH’ to assist with lateral movement.
The malware was only detected after a bank identified the Metasploit Meterpreter code running in physical memory on a central domain controller (DC).
Kaspersky Labs is not the only company to have identified such emerging trends, with most of the principal IT security anti-malware companies coming forward with similar findings: Symantec, Trend Micro, and Cybereason.
Digital forensics
The emergence of malware that operates in a fileless way presents a major problem to digital forensic investigators, whose reliance on being able to obtain digital artifacts from a crime scene is critical to ensuring chain of custody and producing evidence that is admissible in a court of law.
Many well-known digital forensic process models such as: Casey 2004, DFRWS 2001, NIJ 2004, Cohen 2009, all embed either an examination and/or analysis phase into their respective models, implying that evidence can be obtained/collected/preserved by some mechanism.
The difficulty becomes apparent when considering the standard operating procedures of digital investigators and how they should deal with a computer at a crime scene. Traditional methods direct the investigator to:
Do not, in any circumstances, switch the computer on
Make sure that the computer is switched off – some screen savers may give the appearance that the computer is switched off, but hard drive and monitor activity lights may indicate that the machine is switched on.
Remove the main power source battery from laptop computers.
Unplug the power and other devices from sockets on the computer itself
Fileless malware subverts the forensics models, as evidence acquisition can only take place against a memory image that has been obtained from a live running system that is to be investigated. This method, however, can itself compromise the acquired host's memory image and render legal admissibility questionable, or at the very least, instill enough reasonable doubt that the weight of the evidence presented may be drastically reduced, increasing the chances that Trojan horse or "some other dude done it" defenses may be used more effectively.
This renders this type of malware extremely attractive to adversaries wishing to secure a foothold in a network, perform difficult to trace lateral movement and do so in a quick and silent manner, when standard forensic investigatory practices are ill-prepared for the threat.
Notable attacks
Democratic National Committee cyber attacks
References
External links
Fileless malware: An evolving threat on the horizon
Say Hello to the Super-Stealthy Malware That’s Going Mainstream
Fileless Malware Takes 2016 By Storm
New Fileless Attack Using DNS Queries to Carry Out PowerShell Commands
Kovter becomes almost file-less, creates a new file type, and gets some new certificates
Computer forensics
Types of malware | Fileless malware | [
"Engineering"
] | 1,432 | [
"Cybersecurity engineering",
"Computer forensics"
] |
53,250,430 | https://en.wikipedia.org/wiki/India%20Stack | India Stack refers to the project of creating a unified software platform to bring India's population into the digital age. Its website describes its mission as follows: "India Stack is a set of open APIs that allows governments, businesses, startups and developers to utilize a unique digital Infrastructure to solve India’s hard problems towards presence-less, paperless, and cashless service delivery" Of the four "distinct technology layers" mentioned on the same page, the first, the "Presenceless Layer" is the most controversial as it involves storing biometric data such as fingerprints for every citizen. Since such markers are widely being adopted to enable cashless payment, the issue arises of fraudulent use of biometrics. The other layers are the Paperless Layer, which enables personal records to be associated with one's online identity; the Cashless Layer, a single interface to all national banks and online wallets; and the Consent Layer, which aims to maintain security and control of personal data.
India Stack is the largest open API in the world. Since its deployment, India has been organizing hackathons to develop applications for the APIs.
India Stack is being implemented in stages, starting with the introduction in 2009 of the Aadhaar "Universal ID" numbers. These are linked to biometrics (fingerprints) and as time goes by, authentication by Aadhaar is required for access to more and more services and subsidies. This raises issues of privacy and surveillance, especially as much of the users' interface is via their mobile phones.
The next stages were the introduction of eKYC (electronic Know Your Customer), which enables paperless and rapid verification of address, identity etc., followed by eSign, whereby users attach a legally valid electronic signature to a document, and Unified Payments Interface (UPI) enabling cashless payments, and most recently, DigiLocker, a platform for issuance and verification of documents and certificates.
What raised the profile of Aadhaar and India Stack worldwide was the 2016 Indian banknote demonetisation whereby and notes were phased out, officially to eliminate forgeries and money-laundering, but with the secondary objective of hastening the transition to a cashless economy.
Observers have argued that India Stack could fast-track the move to digital payment systems across the developed world and mark the end of cash. However, various challenges related to user rights have been mounted: in August 2017, the Supreme Court of India unanimously ruled in favour of a petition applying for privacy to be declared a fundamental right and other court matters followed.
Reputed consultancy firm Ernst & Young has said that India Stack has become the global benchmark for most countries.
First pilot of India Stack
To test all 4 layers- Presenceless, paperless, cashless and consent- of India stack, the India Stack team partnered with the largest FinTech alternative credit company in India, Capital Float (now axio) in 2016. The objective of the pilot was to provide loans to customers in a few minutes and in the comfort of their own house. Additionally, the target customer was someone with no collateral and limited data trail. When a user opened the application, he/she had to give consent for Capital Float to access his/her data through the digital platform (Consent). Once the consent was given Capital Float used the Aadhaar infrastructure to authenticate the users (presenceless). The Aadhaar also helped with e-KYC, a mandatory requirement for all loan activities in India. Once the authentication was complete, Capital Float pinged the Aadhaar database to check for banking activity, and also used a mobile scraping technique to gather data from the customer's phone. These two steps helped Capital Float estimate the credit-worthiness of the customer. Once this was determined, the customer of the application saw loan offers on the screen. The customer could then select the offer and do an e-signature within the comforts of their home (paperless). This whole process could be completed in 45 seconds. Once the loan was approved it could directly be disbursed into the bank account of the customer (Cashless). The pull function of the UPI platform could also be utilized by Capital Float to get back the loan payments.
After the Pilot, the India Stack team has approached other alternate lenders to utilize the platform to give loans to under-served populations. Capital Float is already in the process of expanding the pilot in to a full-fledged service offering. This pilot proved a clear value proposition of the India Stack platform for the fintech industry.
India Stack Developer Conference
First conference was held on 25 January 2023. NASSCOM president Debjani Ghosh highlighted that India Stack has enabled India to achieve financial inclusion for 80% of population in 6 years as compared to projected figure of 46 years. Indian Minister said that the platform will be offered to other countries and private entrepreneurs free of cost. Earlier India Stack Knowledge Exchange 2022 had taken place in July 2022, where Indiastack.global was launched by Indian PM Narendra Modi as a single repository of all major projects on India Stack.
Components under IndiaStack
Ayushman Bharat Digital Mission
Bharat Bill Payment System
BharatQR
DigiLocker
DigiYatra
eSign
Government e Marketplace(GeM)
Unified Payments Interface(UPI)
UMANG
Open Credit Enablement Network (OCEN)
Open Network for Digital Commerce
FASTag
Aadhaar Enabled Payment System(AePS)
Aadhar Pay
eKYC
Endorsement by IMF
International Monetary Fund endorsed this initiative by noting that: "Other emerging market and developing economies could learn from the experience." In a paper titled India’s Approach to Open Banking: Some Implications for Financial Inclusion, authors Yan Carriere-Swallow, V. Haksar and Manasa Patnam observed that the digital infrastructures of India Stack has enabled rapid increase in digital payments.
Global Collaboration
Sri Lanka, Morocco, the Philippines, Guinea, Ethiopia, and the Togolese Republic have already started using technologies of India Stack
and Tunisia, Samoa, Uganda, and Nigeria have shown their willingness.
Concerns
Financial Times in an article raised concerns around privacy and data protection.
See also
Aadhaar
Unified Payments Interface
Protean eGov Technologies
Immediate Payment Service
National Payments Corporation of India
References
Application programming interfaces
Public services of India
Financial services in India
E-government in India
Projects in Asia
Biometrics
Monetary reform
National identification numbers
Software projects | India Stack | [
"Technology",
"Engineering"
] | 1,300 | [
"Software projects",
"Information technology projects"
] |
53,250,438 | https://en.wikipedia.org/wiki/LogicLocker | LogicLocker, is a cross-vendor ransomware worm that targets Programmable Logic Controllers (PLCs) used in Industrial Control Systems (ICS). First described in a research paper released by the Georgia Institute of Technology, the malware is capable of hijacking multiple PLCs from various popular vendors. The researchers, using a water treatment plant model, were able to demonstrate the ability to display false readings, shut valves and modify Chlorine release to poisonous levels using a Schneider Modicon M241, Schneider Modicon M221 and an Allen Bradley MicroLogix 1400 PLC. The ransomware is designed to bypass weak authentication mechanisms found in various PLCs and lock out legitimate users while planting a logicbomb into the PLC. As of 14 February 2017, it is noted that there are over 1,400 of the same PLCs used in the proof-of-concept attack that were accessible from the internet as found using Shodan.
Attack method
The attack method used with LogicLocker employs five stages. Initial infection, Horizontal and Vertical movement, locking, encryption and negotiation. Initial infection can take place through various vulnerability exploits. As ICS devices are typically in an always on state, this gives Cyber-criminals ample time to attempt the compromise of the PLC. PLCs generally do not have strong authentication mechanisms in place to assist in protecting themselves from potential attack. Initial infection could take place through a users clicking of a potentially malicious email attachment. Upon initial infection of the PLC, horizontal or vertical movement can be achieved from the PLC to the corporate network depending on the capabilities of the PLC. The next stage of the attack is locking in which the attacker locks out legitimate users to inhibit or prevent restoration efforts. This can be done through password changes, OEM Locking, over-utilization of PLC resources or changing IP/Ports. These different locking methods offer varying degrees of success and strengths. To further ensure a successful attack Encryption is employed to follow traditional cryptoransomware practices for future negotiations. Lastly, negotiations are conducted between the attacker and victim for service restoration. Some PLCs contain an email capability that can be used to send the ransom message as was the case with the MicroLogix 1400 PLC used in the proof-of-concept attack.
Defense strategies
To assist in defense and vulnerability mitigation efforts there are several strategies that can be employed.
Endpoint security
Endpoint security techniques such as password changes, disabling of unused ports and protocols and implementation of Access Control Lists (ACL), maintaining proper backups and firmware updates should be used. This can significantly reduce the attack surface presented cyber-criminals.
Network security
Increased and vigilant network monitoring should be used to detect abnormalities. Protocol whitelisting on firewalls, network segmentation and automated backups can provide additional security and provide decreased restoration time provided the backups are not compromised in the attack.
Policy
The training of employees to properly identify phishing emails, prohibition of USB devices and incorporating a comprehensive incident response plan should be used to assist in countering this threat.
See also
Pin control attack
Stuxnet
References
Computer worms
Ransomware
2017 in computing
Cryptographic attacks | LogicLocker | [
"Technology"
] | 634 | [
"Cryptographic attacks",
"Computer security exploits"
] |
53,250,541 | https://en.wikipedia.org/wiki/NGC%204707 | NGC 4707 is an irregular galaxy in the constellation of Canes Venatici. It was discovered by John Herschel on 5 June 1834, and described by John Louis Emil Dreyer, the compiler of the New General Catalogue, as a "small, stellar" galaxy.
NGC 4707 has a morphological type of Sm or Im, meaning that it is mostly irregular or has very weak spiral arms. The galaxy was imaged by the Hubble Space Telescope in 2016. The image showed the galaxy had little to no signs of a central bulge or any prominent structures (typical of Magellanic-type spirals). However, the telescope could resolve many stars, as well as several turquoise-colored star forming regions.
Gallery
References
External links
Irregular galaxies
4707
07971
043255
Canes Venatici | NGC 4707 | [
"Astronomy"
] | 166 | [
"Canes Venatici",
"Galaxy stubs",
"Astronomy stubs",
"Constellations"
] |
53,251,595 | https://en.wikipedia.org/wiki/WHO%20Model%20List%20of%20Essential%20Medicines%20for%20Children | The WHO Model List of Essential Medicines for Children (aka Essential Medicines List for Children or EMLc), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe in children up to twelve years of age to meet the most important needs in a health system.
The list is divided into core items and complementary items. The core items are deemed to be the most cost-effective options for key health problems and are usable with little additional health care resources. The complementary items either require additional infrastructure such as specially trained health care providers or diagnostic equipment or have a lower cost–benefit ratio.
The first list for children was created in 2007, and the list is in its 9th edition .
Note: An α indicates a medicine is on the complementary list.
Anaesthetics, preoperative medicines and medical gases
General anaesthetics and oxygen
Inhalational medicines
Halothane
Isoflurane
Nitrous oxide
Oxygen
Injectable medicines
Ketamine
Propofol
Local anaesthetics
Bupivacaine
Lidocaine
Lidocaine/epinephrine (lidocaine + epinephrine)
Preoperative medication and sedation for short-term procedures
Atropine
Midazolam
Morphine
Medical gases
Oxygen
Medicines for pain and palliative care
Non-opioids and non-steroidal anti-inflammatory medicines (NSAIMs)
Ibuprofen
Paracetamol (acetaminophen)
Opioid analgesics
Morphine
Methadone
Medicines for other symptoms common in palliative care
Amitriptyline
Cyclizine
Dexamethasone
Diazepam
Docusate sodium
Fluoxetine
Hyoscine hydrobromide
Lactulose
Midazolam
Ondansetron
Senna
Antiallergics and medicines used in anaphylaxis
Dexamethasone
Epinephrine (adrenaline)
Hydrocortisone
Loratadine
Prednisolone
Antidotes and other substances used in poisonings
Non-specific
Charcoal, activated
Specific
Acetylcysteine
Atropine
Calcium gluconate
Naloxone
Deferoxamine
Dimercaprol
Fomepizole
Sodium calcium edetate
Succimer
Anticonvulsants/antiepileptics
Carbamazepine
Diazepam
Lamotrigine
Lorazepam
Midazolam
Phenobarbital
Phenytoin
Valproic acid (sodium valproate)
Ethosuximide
Valproic acid (sodium valproate)
Anti-infective medicines
Anthelminthics
Intestinal anthelminthics
Albendazole
Ivermectin
Levamisole
Mebendazole
Niclosamide
Praziquantel
Pyrantel
Antifilarials
Albendazole
Diethylcarbamazine
Ivermectin
Antischistosomals and other antinematode medicines
Praziquantel
Triclabendazole
Oxamniquine
Cysticidal medicines
Albendazole
Mebendazole
Praziquantel
Antibacterials
Access group antibiotics
Amikacin
Amoxicillin
Amoxicillin/clavulanic acid (amoxicillin + clavulanic acid)
Ampicillin
Benzathine benzylpenicillin
Benzylpenicillin
Cefalexin
Cefazolin
Chloramphenicol
Clindamycin
Cloxacillin
Doxycycline
Gentamicin
Metronidazole
Nitrofurantoin
Phenoxymethylpenicillin (penicillin V)
Procaine benzylpenicillin
Sulfamethoxazole/trimethoprim (sulfamethoxazole + trimethoprim)
Trimethoprim
Watch group antibiotics
Azithromycin
Cefixime
Cefotaxime
Ceftriaxone
Cefuroxime
Ciprofloxacin
Clarithromycin
Piperacillin/tazobactam (piperacillin + tazobactam)
Vancomycin
Ceftazidime
Meropenem
Vancomycin
Reserve group antibiotics
Reserve antibiotics are last-resort antibiotics. The EML antibiotic book was published in 2022.
Ceftazidime/avibactam (ceftazidime + avibactam)
Colistin
Fosfomycin
Linezolid
Polymyxin B
Antileprosy medicines
Clofazimine
Dapsone
Rifampicin
Antituberculosis medicines
Ethambutol
Isoniazid
Isoniazid/pyrazinamide/rifampicin (isoniazid + pyrazinamide + rifampicin)
Isoniazid/rifampicin (isoniazid + rifampicin)
Isoniazid/rifapentine (isoniazid + rifapentine)
Pyrazinamide
Rifampicin
Rifapentine
Amikacin
Amoxicillin/clavulanic acid (amoxicillin + clavulanic acid)
Bedaquiline
Clofazimine
Cycloserine
Delamanid
Ethionamide
Levofloxacin
Linezolid
Meropenem
Moxifloxacin
P-aminosalicylic acid
Streptomycin
Antifungal medicines
Amphotericin B
Fluconazole
Flucytosine
Griseofulvin
Itraconazole
Nystatin
Voriconazole
Micafungin
Potassium iodide
Antiviral medicines
Antiherpes medicines
Aciclovir
Antiretrovirals
Nucleoside/nucleotide reverse transcriptase inhibitors
Lamivudine
Zidovudine
Non-nucleoside reverse transcriptase inhibitors
Nevirapine
Protease inhibitors
Darunavir
Lopinavir/ritonavir (lopinavir + ritonavir)
Ritonavir
Integrase inhibitors
Dolutegravir
Raltegravir
Fixed-dose combinations of antiretroviral medicines
Abacavir/lamivudine (abacavir + lamivudine)
Lamivudine/zidovudine (lamivudine + zidovudine)
Medicines for prevention of HIV-related opportunistic infections
Isoniazid/pyridoxine/sulfamethoxazole/trimethoprim (isoniazid + pyridoxine + sulfamethoxazole + trimethoprim)
Other antivirals
Ribavirin
Oseltamivir
Valganciclovir
Antihepatitis medicines
Medicines for hepatitis B
Nucleoside/Nucleotide reverse transcriptase inhibitors
Entecavir
Medicines for hepatitis C
Pangenotypic direct-acting antiviral combinations
Daclatasvir
Daclatasvir/sofosbuvir (daclatasvir + sofosbuvir)
Glecaprevir/pibrentasvir (glecaprevir + pibrentasvir)
Sofosbuvir
Sofosbuvir/velpatasvir (sofosbuvir + velpatasvir)
Non-pangenotypic direct-acting antiviral combinations
No listings in this section.
Other antivirals for hepatitis C
No listings in this section.
Antiprotozoal medicines
Antiamoebic and antigiardiasis medicines
Diloxanide
Metronidazole
Antileishmaniasis medicines
Amphotericin B
Miltefosine
Paromomycin
Sodium stibogluconate or meglumine antimoniate
Antimalarial medicines
For curative treatment
Amodiaquine
Artemether
Artemether/lumefantrine (artemether + lumefantrine)
Artesunate
Artesunate/amodiaquine (artesunate + amodiaquine)
Artesunate/mefloquine (artesunate + mefloquine)
Artesunate/pyronaridine tetraphosphate (artesunate + pyronaridine tetraphosphate)
Chloroquine
Dihydroartemisinin/piperaquine phosphate (dihydroartemisinin + piperaquine phosphate)
Doxycycline
Mefloquine
Primaquine
Quinine
Sulfadoxine/pyrimethamine (sulfadoxine + pyrimethamine)
For chemoprevention
Amodiaquine + sulfadoxine/pyrimethamine (Co-packaged)
Chloroquine
Doxycycline
Mefloquine
Proguanil
Sulfadoxine/pyrimethamine (sulfadoxine + pyrimethamine)
Antipneumocystosis and antitoxoplasmosis medicines
Pyrimethamine
Sulfadiazine
Sulfamethoxazole/trimethoprim (sulfamethoxazole + trimethoprim)
Antitrypanosomal medicines
African trypanosomiasis
Fexinidazole
1st stage
Pentamidine
Suramin sodium
2nd stage
Eflornithine
Nifurtimox
Melarsoprol
American trypanosomiasis
Benznidazole
Nifurtimox
Medicines for ectoparasitic infections
Ivermectin
Antimigraine medicines
For treatment of acute attack
Ibuprofen
Paracetamol
For prophylaxis
Propranolol
Immunomodulators and Antineoplastics
Immunomodulators for non-malignant disease
Adalimumab
Azathioprine
Ciclosporin
Tacrolimus
Antineoplastic and supportive medicines
Cytotoxic medicines
Arsenic trioxide
Asparaginase
Bleomycin
Calcium folinate
Carboplatin
Cisplatin
Cyclophosphamide
Cytarabine
Dacarbazine
Dactinomycin
Daunorubicin
Doxorubicin
Etoposide
Fluorouracil
Hydroxycarbamide
Ifosfamide
Irinotecan
Mercaptopurine
Methotrexate
Oxaliplatin
Paclitaxel
Pegaspargase
Procarbazine
Realgar/Indigo naturalis
Tioguanine
Vinblastine
Vincristine
Vinorelbine
Targeted therapies
All-trans retinoid acid (ATRA)
Dasatinib
Everolimus
Imatinib
Nilotinib
Rituximab
Immunomodulators
Filgrastim
Hormones and antihormones
Dexamethasone
Hydrocortisone
Methylprednisolone
Prednisolone
Supportive medicines
Allopurinol
Mesna
Rasburicase
Medicines affecting the blood
Antianaemia medicines
Ferrous salt
Folic acid
Hydroxocobalamin
Erythropoiesis-stimulating agents
Medicines affecting coagulation
Enoxaparin
Phytomenadione
Desmopressin
Heparin sodium
Protamine sulfate
Warfarin
Other medicines for haemoglobinopathies
Deferoxamine
Hydroxycarbamide
Blood products of human origin and plasma substitutes
Blood and blood components
Fresh frozen plasma
Platelets
Red blood cells
Whole blood
Plasma-derived medicines
Human immunoglobulins
Anti-rabies immunoglobulin
Anti-tetanus immunoglobulin
Normal immunoglobulin
Blood coagulation factors
Coagulation factor VIII
Coagulation factor IX
Plasma substitutes
Dextran 70
Cardiovascular medicines
Antianginal medicines
No listings in this section.
Antiarrhythmic medicines
No listings in this section.
Antihypertensive medicines
Enalapril
Medicines used in heart failure
Digoxin
Furosemide
Dopamine
Antithrombotic medicines
No listings in this section.
Lipid-lowering agents
No listings in this section.
Dermatological medicines (topical)
Antifungal medicines
Miconazole
Terbinafine
Anti-infective medicines
Mupirocin
Potassium permanganate
Silver sulfadiazine
Anti-inflammatory and antipruritic medicines
Betamethasone
Calamine
Hydrocortisone
Medicines affecting skin differentiation and proliferation
Benzoyl peroxide
Calcipotriol
Coal tar
Podophyllum resin
Salicylic acid
Urea
Scabicides and pediculicides
Benzyl benzoate
Permethrin
Diagnostic agents
Ophthalmic medicines
Fluorescein
Tropicamide
Radiocontrast media
Barium sulfate
Disinfectants and antiseptics
Antiseptics
Chlorhexidine
Ethanol
Povidone iodine
Disinfectants
Alcohol based hand rub
Chlorine base compound
Chloroxylenol
Glutaral
Diuretics
Furosemide
Hydrochlorothiazide
Mannitol
Spironolactone
Gastrointestinal medicines
Pancreatic enzymes
Antiulcer medicines
Omeprazole
Ranitidine
Antiemetic medicines
Dexamethasone
Metoclopramide
Ondansetron
Aprepitant
Anti-inflammatory medicines
No listings in this section.
Laxatives
No listings in this section.
Medicines used in diarrhoea
Oral rehydration salts + zinc sulfate (Co-packaged)
Oral rehydration
Oral rehydration salts
Medicines for diarrhoea
Zinc sulfate
Medicines for endocrine disorders
Adrenal hormones and synthetic substitutes
Fludrocortisone
Hydrocortisone
Androgens
No listings in this section.
Estrogens
No listings in this section.
Progestogens
No listings in this section.
Medicines for diabetes
Insulins
Insulin injection (soluble)
Intermediate-acting insulin
Long-acting insulin analogues
Oral hypoglycaemic agents
Metformin
Medicines for hypoglycaemia
Glucagon
Diazoxide
Thyroid hormones and antithyroid medicines
Levothyroxine
Lugol's solution
Methimazole
Potassium iodide
Propylthiouracil
Immunologicals
Diagnostic agents
Tuberculin, purified protein derivative (PPD)
Sera and immunoglobulins
Anti-rabies virus monoclonal antibodies
Antivenom immunoglobulin
Diphtheria antitoxin
Equine rabies immunoglobulin
Vaccines
Recommendations for all
BCG vaccine
Diphtheria vaccine
Haemophilus influenzae type b vaccine
Hepatitis B vaccine
HPV vaccine
Measles vaccine
Pertussis vaccine
Pneumococcal vaccine
Poliomyelitis vaccine
Rotavirus vaccine
Rubella vaccine
Tetanus vaccine
Recommendations for certain regions
Japanese encephalitis vaccine
Yellow fever vaccine
Tick-borne encephalitis vaccine
Recommendations for some high-risk populations
Cholera vaccine
Dengue vaccine
Hepatitis A vaccine
Meningococcal meningitis vaccine
Rabies vaccine
Typhoid vaccine
Recommendations for immunization programmes with certain characteristics
Influenza vaccine
Mumps vaccine
Varicella vaccine
Muscle relaxants (peripherally-acting) and cholinesterase inhibitors
Neostigmine
Suxamethonium
Vecuronium
Pyridostigmine
Ophthalmological preparations
Anti-infective agents
Aciclovir
Azithromycin
Erythromycin
Gentamicin
Natamycin
Ofloxacin
Tetracycline
Anti-inflammatory agents
Prednisolone
Local anaesthetics
Tetracaine
Miotics and antiglaucoma medicines
No listings in this section.
Mydriatics
Atropine
Epinephrine (adrenaline)
Anti-vascular endothelial growth factor (VEGF) preparations
No listings in this section.
Medicines for reproductive health and perinatal care
Contraceptives
No listings in this section.
Ovulation inducers
No listings in this section.
Uterotonics
No listings in this section.
Antioxytocics (tocolytics)
No listings in this section.
Other medicines administered to the mother
No listings in this section.
Medicines administered to the neonate
Caffeine citrate
Chlorhexidine
Ibuprofen
Prostaglandin E1
Surfactant
Peritoneal dialysis solution
Intraperitoneal dialysis solution (of appropriate composition)
Medicines for mental and behavioural disorders
Medicines used in psychotic disorders
Chlorpromazine
Haloperidol
Medicines used in mood disorders
Medicines used in depressive disorders
Fluoxetine
Medicines used in bipolar disorders
No listings in this section.
Medicines for anxiety disorders
No listings in this section.
Medicines used for obsessive compulsive disorders
No listings in this section.
Medicines for disorders due to psychoactive substance use
No listings in this section.
Medicines acting on the respiratory tract
Antiasthmatic medicines
Budesonide
Epinephrine (adrenaline)
Salbutamol (albuterol)
Solutions correcting water, electrolyte and acid-base disturbances
Oral
Oral rehydration salts
Potassium chloride
Parenteral
Glucose
Glucose with sodium chloride
Potassium chloride
Sodium chloride
Sodium hydrogen carbonate
Sodium lactate, compound solution
Miscellaneous
Water for injection
Vitamins and minerals
Ascorbic acid
Cholecalciferol
Iodine
Multiple micronutrient powder
Pyridoxine
Retinol
Riboflavin
Thiamine
Calcium gluconate
Ear, nose and throat medicines
Acetic acid
Budesonide
Ciprofloxacin
Xylometazoline
Medicines for diseases of joints
Medicines used to treat gout
No listings in this section.
Disease-modifying agents used in rheumatoid disorders
Hydroxychloroquine
Methotrexate
Juvenile joint diseases
Aspirin
Dental preparations
Fluoride
Glass ionomer cement
Silver diammine fluoride
Notes
References
Further reading
External links
Children
2007 introductions
Drug-related lists | WHO Model List of Essential Medicines for Children | [
"Chemistry"
] | 3,679 | [
"Drug-related lists"
] |
53,252,845 | https://en.wikipedia.org/wiki/Glossary%20of%20calculus | Most of the terms listed in Wikipedia glossaries are already defined and explained within Wikipedia itself. However, glossaries like this one are useful for looking up, comparing and reviewing large numbers of terms together. You can help enhance this page by adding new terms or writing definitions for existing ones.
This glossary of calculus is a list of definitions about calculus, its sub-disciplines, and related fields.
A
B
C
D
E
F
G
H
I
J
L
M
N
O
P
Q
R
S
T
U
V
W
See also
Outline of calculus
Glossary of areas of mathematics
Glossary of astronomy
Glossary of biology
Glossary of botany
Glossary of chemistry
Glossary of ecology
Glossary of engineering
Glossary of physics
Glossary of probability and statistics
References
Works cited
.
.
.
.
Notes
C
Wikipedia glossaries using description lists | Glossary of calculus | [
"Mathematics"
] | 163 | [
"Calculus"
] |
53,256,083 | https://en.wikipedia.org/wiki/Memory%20ballooning | In computing, memory ballooning is a technique that is used to eliminate the need to overcommit host memory used by virtual machines (VMs) by letting each VM effectively "give back" unused pages of [virtual] memory.
To implement memory ballooning, the virtual machine's kernel implements a "balloon driver" that allocates unused memory within the VM's address space into a pool of memory (the "balloon"), which makes that memory unavailable to other processes on that VM. The balloon driver doesn't use the pool of memory; instead it tells the host operating system's hypervisor which memory addresses are in that pool (unused). The host operating system then unmaps physical memory from those memory pages (with no need to copy them to secondary storage). The released pages of physical memory return to the host machine's pool of available RAM, and the host machine can use them to keep other virtual machines in physical memory and/or to cache secondary storage.
Depending on the amount of memory required by applications running on the VM, the balloon driver inside the VM can dynamically decrease or increase the number of pages in its "balloon", causing the host computer to remap or unmap physical memory to the VM, as-needed.
References
See also
Memory overcommitment
Thin provisioning
Memory management
Virtual machines | Memory ballooning | [
"Technology"
] | 285 | [
"Computing stubs",
"Computer science",
"Computer science stubs"
] |
53,257,253 | https://en.wikipedia.org/wiki/Kristen%20Hawkes | Kristen Hawkes is an American anthropologist, currently a professor at University of Utah. In 2021 she was elected to the American Philosophical Society.
Education
Hawkes received a bachelor's degree in Sociology and Anthropology from Iowa State University and a Masters in Anthropology from the University of Washington. She was awarded a PhD in Anthropology for her research into kinship and cooperation among the Binumarien a highland community in New Guinea.
Research
Hawkes, an expert in human evolution and sociobiology, is the author of several studies on the “grandmother hypothesis,” which asserts that many of the characteristics that distinguish us from our ape ancestors are thanks to the thoughtful care of our mothers' mothers.
Her research is based on ethnographic observation studies of hunter-gatherer communities such as the Aché and Hadza.
She has also developed mathematical models to model evolution over time and trace the influence of grandmothers on human lifespan.
Combining mathematical modelling and observational studies she also researches the effects of fire on ancient hunter-gatherers.
See also
Grandmother hypothesis
References
Year of birth missing (living people)
Living people
University of Utah faculty
21st-century American anthropologists
Members of the United States National Academy of Sciences
Members of the American Philosophical Society
Behavioral ecology | Kristen Hawkes | [
"Biology"
] | 244 | [
"Behavioural sciences",
"Ethology",
"Behavior",
"Behavioral ecology"
] |
53,257,288 | https://en.wikipedia.org/wiki/HSH2D | Hematopoietic SH2 Domain Containing (HSH2D) protein is a protein encoded by the hematopoietic SH2 domain containing (HSH2D) gene.
Gene
HSH2D is located on chromosome 19 at 19p13.11. Common aliases of the gene include HSH2 (Hematopoietic SH2 Protein) and ALX (Adaptor in Lymphocytes of Unknown Function X). The mRNA encodes two main isoforms. Isoform 1, the longest isoform, contains seven exons. The gene spans from 16134028 to 16158575.
mRNA
Two main isoforms of HSH2D exist. Isoform 1 has seven exons and is 2,403 bp in length. Isoform 2 has six exons and is 2,936 bp long. Although isoform 2 has longer mRNA, it still produces the smaller isoform in the mature protein. Isoform 2 has a variant 5’ UTR and a different start codon, as well as a shorter N-terminus. The mRNA has a short 5' UTR and a long 3' UTR.
Protein
The protein has a molecular weight of 39.0 kilodaltons (kDa) and a pI of 6.678. The main feature of the protein is the SH2 (Src homology) domain, which is a region that has phosphotyrosine receptors and is important in many signaling molecules. This domain is located from residues 26-127.
The secondary structure of the protein contains a helical section around residues 40-50, a sheet between 60-70, helices between 100-110, 135-145, 175-180, 200-225, and additional sheets between 235-240 and 295-300, shown in the figure at the bottom of the section (helices are purple arrows and sheets are red arrows). The protein has several locations of post-translational modifications, especially phosphorylation and GalNAc O-glycosylation, which has been shown to play a role in cancers.
The tertiary structure of the protein has not been confirmed through research, however, predictions using I-TASSER software are useful in visualizing the protein.
Expression
Based on NCBI GEO expression profiles and EST analyses, the protein appears to be narrowly expressed throughout human tissues. It is highly expressed in bone marrow, CD4+ and CD8+ T cells, lymph node, mammary gland, spleen, stomach, thyroid, and small intestine tissue. Expression is elevated in cases of early T-cell precursor acute lymphoblastic leukemia and lowered in breast cancer cells that are treated with estrogen, suggesting an interaction between the protein and estrogen.
Function
The function of the HSH2D protein is still not fully understood, however it has been shown to play a role in various cellular functions such as apoptosis, wound healing, vascular endothelial growth factors, membrane-associated intracellular trafficking, biogenesis of lipid droplets and collagen remodeling. It is also thought to play a role in T-cell activation.
Interacting proteins
HSH2D interacts with several proto-oncogenes, including FES proto-oncogene (FES) and CRK proto-oncogene (CRK). It also has suspected interactions with other proteins such as tyrosine kinase non-receptor 2 (TRK2), PTEN-induced putative kinase (PINK1), and Interleukin 2 (IL2). A summary of these proteins is shown below with their suspected functions.
Clinical significance
The HSH2D protein has been studied along other human genes predicted to be involved in the human immune system. HSH2D was found to be highly expressed in patients with ulcerative colitis. The protein is also associated with alpha-interferon activity.
Homology
HSH2D has four distant paralogs and several orthologs in other species that have high levels of conservation.
Paralogs
The four paralogs of HSH2D in humans are other proteins containing SH2 domains. They do not have a high level of conservation other than this domain. All paralogs were found through genecards
Orthologs
HSH2D has several orthologous proteins that span across several orders of species. The protein was well conserved across mammals as well as a few reptiles, amphibians, and invertebrates. The following list is not exhaustive, rather, it shows the wide range of organisms that the protein may be found in. All orthologous proteins were found with BLAST or BLAT programs.
References
Proteins | HSH2D | [
"Chemistry"
] | 977 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
53,257,421 | https://en.wikipedia.org/wiki/Lorin%20Hitt | Lorin M. Hitt is an American economist, currently the Zhang Jingdong Professor of Operations, Information and Decisions at the Wharton School of the University of Pennsylvania.
Bibliography
References
Year of birth missing (living people)
Living people
University of Pennsylvania faculty
American economists
Information systems researchers | Lorin Hitt | [
"Technology"
] | 56 | [
"Information systems",
"Information systems researchers"
] |
53,258,148 | https://en.wikipedia.org/wiki/Scandiweb | scandiweb is a web development and digital strategy agency specializing in the Magento (Adobe Commerce) platform. The company was established in 2003 in Latvia by Antons Sapriko. It has offices in the United States, Sweden, Latvia, and Georgia. scandiweb provides solutions for primarily eCommerce businesses and acts as a strategic partner for IT development focusing on web, mobile, and big data analysis. Their work is centered mainly around Magento but also includes web development on other platforms, like Shopify, BigCommerce, Shopware, and others, 3rd party integration, growth marketing—SEO, PPC, CRO, email marketing, performance optimization, hosting, data analytics, and security services.
History
scandiweb was established in 2003 by the founder, Antons Sapriko. For the first few years, scandiweb functioned as a content aggregation startup and later pivoted into a web design agency launching 300 sites on custom-made CMS.
scandiweb's founder moved to Denmark in 2008 to study and began learning about the Magento platform, expanding service delivery to the Netherlands and the United Kingdom.
After 7 years of fixing small and large Magento projects, scandiweb began taking on projects that required full delivery care, from ideation to implementation and support. In 2017, in addition to the development teams, the agency opened a Growth department of 100+ team members who work on CX audits, data and analytics setups, conversion rate optimization, A/B testing, UI, technical SEO, and PPC campaigns.
During the next several years, scandiweb's team and client base grew exponentially. In 2024, scandiweb is a remote-first agency specializing in web development and digital strategy with 600+ employees from 35+ countries, serving eCommerce and non-eCommerce companies worldwide.
Partnerships
scandiweb is the official Adobe Silver Partner. With 406 certifications and 286 certified employees, scandiweb is the largest Adobe Commerce-certified team globally.
Since October 2016, scandiweb has been partnering with Oro, Inc., an open-source business application development firm, and has created an integrated eCommerce CRM solution based on the synthesis of Magento and Oro’s proprietary OroCRM system.
scandiweb is the Gold Partner of Hyvä, a Magento 2 frontend theme that optimizes performance metrics like PageSpeed scores and Core Web Vitals while preserving functionality and design. scandiweb has worked with Hyvä since early 2022.
scandiweb is the official Sanity Agency Partner and assists with content management for all technical deliveries. Sanity is a headless content management system (CMS) that allows content to be reused endlessly across various channels and manages text, images, and other media with APIs.
scandiweb is the Klaviyo Agency Partner with the Silver Master badge. Klaviyo is an intelligent marketing automation platform powered by customer data.
scandiweb became a Pimcore Silver partner in April 2023 and was promoted to the Pimcore Gold Partner tier in August of the same year. In 2024, scandiweb became a Pimcore Platinum Partner. Pimcore is a leading product information management solution for Magento. scandiweb has also developed Pimcore Connector, an extension that enables integration between Pimcore and Magento 2.
scandiweb is also partnered with Shopify, BigCommerce, WooCommerce, Shopware, Webflow, Marello, AWS, personalization solutions Attraqt, Klevu, Clerk.io, payment providers Mondu, checkout.com, Bolt, and We are Planet, marketing tools DotDigital, CallRail, TikTok, VWO, Bloomreach, Segment, and Hotjar, and translation agencies Lokalise and Weglot.
Events and tools for the ecosystem
scandiweb organized the first-ever Meet Magento event in the Baltics. The event took place in Riga, Latvia, in October 2019. Meet Magento Baltics returned in May 2022 with 3-day virtual sessions and an in-person event in Riga.
scandiweb also hosts the eCOM360 conference, uniting eCommerce practitioners in business, marketing, design, and tech from all around the world. The first conference was held in Riga in 2019. Due to the pandemic, the 2020 conference was postponed and took place in 2021 in a virtual format.
In 2020, scandiweb launched ReadyMage, a scalable hosting platform built to host Adobe Commerce projects.
When Progressive Web Apps first became popular in 2019, scandiweb developed ScandiPWA, an open-source, React-based storefront for Magento with improved UX and performance. ScandiPWA is used by more than 500 brands including Adidas, Levi's, Shure, Puma, Monin, and Buff. Magento PWA development offers a full PWA implementation that can be integrated with an existing Magento store.
Following ScandiPWA's success and wide implementation, scandiweb created Satoshi in 2023. It is a website that features an imagined eCommerce store's mobile experience, a showcase of UX/UI best practices with a tangible demonstration of those practices in action, also available as a theme.
In 2024, scandiweb launched Scandilytics.ai. The scandilytics.ai platform integrates with Google Analytics to provide AI-driven insights, automated reporting, and data-driven decision-making tools. It’s designed for eCommerce businesses that want to leverage the capabilities of OpenAI’s GPT-4 for enhanced data analysis without the need for deep technical expertise.
Accolade
In December 2016, scandiweb constructed the world’s largest Rube Goldberg Machine and entered the Guinness Book of World Records. The machine was used to turn on the lights of Riga’s Christmas tree. The Rube Goldberg deployed a chain reaction consisting of 412 mechanical steps, setting in motion a wide assortment of parts such as levers, balls, and wheels, as well as items like a coffee machine and a fan. The principle of a Rube Goldberg Machine is to achieve a simple task in the most complicated way possible.
In 2023, scandiweb's redesign for a Swiss chocolatier Läderach's website was honored with the Design Curve Award at the 2023 Meet Magento NYC event.
scandiweb has obtained ISO 27001:2022 and ISO 27017:2015 standard certificates.
References
Web development
Software companies of Latvia
Companies of Latvia | Scandiweb | [
"Engineering"
] | 1,391 | [
"Software engineering",
"Web development"
] |
53,258,493 | https://en.wikipedia.org/wiki/Vacuum%20interrupter | In electrical engineering, a vacuum interrupter is a switch which uses electrical contacts in a vacuum. It is the core component of medium-voltage circuit-breakers, generator circuit-breakers, and high-voltage circuit-breakers. Separation of the electrical contacts results in a metal vapour arc, which is quickly extinguished. Vacuum interrupters are widely used in utility power transmission systems, power generation unit, and power-distribution systems for railways, arc furnace applications, and industrial plants.
Since the arc is contained within the interrupter, switchgear using vacuum interrupters are very compact compared with switchgear using air, sulfur hexafluoride (SF6) or oil as arc-suppression medium. Vacuum interrupters can be used for circuit-breakers and load switches. Circuit-breaker vacuum interrupters are used primarily in the power sector in substation and power-generation facilities, and load-switching vacuum interrupters are used for power-grid end users.
History
The use of a vacuum for switching electrical currents was motivated by the observation that a one-centimeter gap in an X-ray tube could withstand tens of thousands of volts. Although some vacuum switching devices were patented during the 19th century, they were not commercially available. In 1926, a group led by Royal Sorensen at the California Institute of Technology investigated vacuum switching and tested several devices; fundamental aspects of arc interruption in a vacuum were investigated. Sorenson presented the results at an AIEE meeting that year, and predicted the switches' commercial use. In 1927, General Electric purchased the patent rights and began commercial development. The Great Depression and the development of oil-filled switchgear caused the company to reduce development work, and little commercially important work was done on vacuum power switchgear until the 1950s.
In 1956, Hugh C. Ross at Jennings Radio Manufacturing Corporation revolutionized the high-frequency-circuit vacuum switch and produced a vacuum switch with a rating of 15 kV at 200 A. Five years later, Thomas H. Lee at General Electric produced the first vacuum circuit breakers with a rated voltage of 15 kV at short-circuit breaking currents of 12.5 kA. In 1966, devices were developed with a rated voltage of 15 kV and short-circuit breaking currents of 25 and 31.5 kA. After the 1970s, vacuum switches began to replace the minimal-oil switches in medium-voltage switchgear. In the early 1980s, SF6 switches and breakers were also gradually replaced by vacuum technology in medium-voltage application.
As of 2018, a vacuum circuit breaker had reached 145 kV and the breaking current had reached 200 kA.
Classification
Vacuum interrupters may be classified by enclosure type, by application, and by voltage class.
Experimental, radio-frequency, and early power-switching vacuum interrupters had glass enclosures. More recently, vacuum interrupters for power switchgear are made with ceramic envelopes.
Applications and uses include circuit-breakers, generator circuit-breaker, load switches, motor contactors, and reclosers. Special-purpose vacuum interrupters are also manufactured, such as those used in transformer tap changers or in electrical arc furnaces.
Generator circuit-breaker
Research and investigation in the early 1990s allowed the employment of vacuum switching technology for generator applications. Generator switching applications are well known for their higher strains on interrupting devices, such as high fault current of high asymmetry or high and steep transient recovery voltage; the standard IEC/IEEE 62271-37-013 (former and still valid IEEE C37.013, 1997) was introduced to address such requirements on circuit breakers used in generator applications.
Vacuum circuit breakers can be qualified as a generator circuit breakers (GCB) according to IEC/IEEE 62271-37-013. Compared to circuit breakers using other quenching media (such as SF6, air-blast or minimum oil), vacuum circuit breakers have the advantages of:
Great recovery strength, eliminating the need for capacitors to reduce the steepness of the transient recovery voltage (as required in most SF6 generator circuit breakers);
High mechanical and electrical durability with significantly higher numbers and frequency of possible switching operations without maintenance; and
Environmental-friendliness by not using SF6.
Vacuum GCBs are suitable for frequent switching duty and for interrupting low-frequency currents as found in pumped storage power plants.
Structure
A vacuum interrupter generally has one fixed and one moving contact, a flexible bellows to allow movement of that contact, and arc shields enclosed in a hermetically-sealed glass, ceramic or metal housing with a high vacuum. The moving contact is connected by a flexible braid to the external circuit, and is moved by a mechanism when the device is required to open or close. Since air pressure tends to close the contacts, the operating mechanism must hold the contacts open against the closing force of air pressure on the bellows.
Airtight enclosure
The interrupter's enclosure is made of glass or ceramic. Hermetic seals ensure that the interrupter vacuum is maintained for the life of the device. The enclosure must be impermeable to gas, and must not give off trapped gas. The stainless-steel bellows isolates the vacuum inside the interrupter from the external atmosphere and moves the contact within a specified range, opening and closing the switch.
Shielding
A vacuum interrupter has shields around the contacts and at the ends of the interrupter, preventing any contact material vaporized during an arc from condensing on the inside of the vacuum envelope. This would reduce the insulation strength of the envelope, ultimately resulting in the arcing of the interrupter when open. The shield also helps control the shape of the electric-field distribution inside the interrupter, contributing to a higher open-circuit voltage rating. It helps absorb some of the energy produced in the arc, increasing a device's interrupting rating.
Contacts
The contacts carry the circuit current when closed, forming the terminals of the arc when open. They are made of a variety of materials, depending on the vacuum interrupter's use and design for long contact life, rapid recovery of voltage withstand rating, and control of overvoltage due to current chopping.
An external operating mechanism drives the moving contact, which opens and closes the connected circuit. The vacuum interrupter includes a guide sleeve to control the moving contact and protect the sealing bellows from twisting, which would drastically shorten its life.
Although some vacuum-interrupter designs have simple butt contacts, contacts are generally shaped with slots, ridges, or grooves to improve their ability to break high currents. Arc current flowing through the shaped contacts generate magnetic forces on the arc column, which cause the arc contact spot to move rapidly over the surface of the contact. This reduces contact wear due to erosion by an arc, which melts the contact metal at the point of contact.
Only a few manufacturers of vacuum interrupters worldwide produce the contact material itself. The basic raw materials, copper and chromium, are combined into the contact material by means of an arc-melting procedure. The resulting raw parts are processed to radial magnetic field (RMF) or axial magnetic field (AMF) contact discs, with the slotted AMF discs deburred at the end. Contact materials require the following:
High breaking ability: Excellent electrical conductivity, small thermal conductivity, greater heat capacity and low hot electron emission capability;
High breakdown voltage and resistance to electrical erosion;
Resistance to welding;
Low cutoff current value; and
Low gas content (especially copper).
In circuit breakers, vacuum-interrupter contact materials are primarily a 50-50 copper-chromium alloy. They may be made by welding a copper–chromium alloy sheet on the upper and lower contact surfaces over a contact seat made of oxygen-free copper. Other materials, such as silver, tungsten and tungsten compounds, are used in other interrupter designs. The vacuum interrupter's contact structure has a great influence on its breaking capacity, electrical durability and level of current chopping.
Bellows
The vacuum interrupter bellows allows the moving contact to be operated from outside the interrupter enclosure, and must maintain a long-term high vacuum over the expected operating life of the interrupter. The bellows is made of stainless steel with a thickness of 0.1 to 0.2 mm. Its fatigue life is affected by heat conducted from the arc.
To enable them to meet the requirements for high endurance in real practice, the bellows are regularly subjected to an endurance test every three months. The test is carried out in a fully automatic test cabin with the travels adjusted to the respective type.
Bellows lifetime are over 30,000 CO operation cycles.
Operation
A vacuum interrupter uses a high vacuum to extinguish the arc between a pair of contacts. As the contacts move apart, current flows through a smaller area. There is a sharp increase in resistance between the contacts, and the temperature at the contact surface increases rapidly until the occurrence of electrode-metal evaporation. At the same time, the electric field is very high across the small contact gap. The breakdown of the gap produces a vacuum arc. As the alternating current is forced to pass through zero thanks to the arc resistance, and the gap between the fixed and moving contacts widens, the conductive plasma produced by the arc moves away from the gap and becomes non-conductive. The current is interrupted.
AMF and RMF contacts have spiral (or radial) slots cut into their faces. The shape of the contacts produces magnetic forces which move the arc spot over the surface of the contacts, so the arc does not remain in one place for very long. The arc is evenly distributed over the contact surface to maintain a low arc voltage and to reduce contact erosion.
Production process
Components of the vacuum interrupter must be thoroughly cleaned before assembly, since contaminants could emit gas into the vacuum envelope. To ensure a high breakdown voltage, components are assembled in a cleanroom where dust is strictly controlled.
After the surfaces have been finished and cleaned by electroplating and an optical inspection of the surface consistency of all single parts has been performed, the interrupter is assembled. High-vacuum solder is applied at the joints of the components, the parts are aligned, and the interrupters are fixed. As cleanliness during assembly is especially important, all operations are done under air-conditioned clean-room conditions. In this way the manufacturer can guarantee a constantly high quality of the interrupters and maximum possible ratings up to 100 kA according to IEC/IEEE 62271-37-013.
Subassemblies of vacuum interrupters were initially assembled and brazed together in a hydrogen-atmosphere furnace. A tube connected to the interrupter's interior was used to evacuate the interrupter with an external vacuum pump while the interrupter was maintained at about . Since the 1970s, interrupter subcomponents have been assembled in a high-vacuum brazing furnace by a combined brazing-and-evacuation process. Tens (or hundreds) of bottles are processed in one batch, using a high-vacuum furnace that heats them at temperatures up to 900 °C and a pressure of 10−6 mbar. Thus, the interrupters fulfill the quality requirement "sealed for lifetime". Thanks to the fully automatic production process, the high quality can be constantly reproduced at any time
Then, the evaluation of the interrupters by means of the X-ray procedure is used to verify the positions as well as the completeness of the internal components, and the quality of the brazing points. It ensures the high quality of vacuum interrupters.
During forming, the definitive internal dielectric strength of the vacuum interrupter is established with gradually increasing voltage, and this is verified by a subsequent lightning impulse voltage test. Both operations are done with higher values than those specified in the standards, as evidence of the quality of the vacuum interrupters. This is the prerequisite for long endurance and high availability.
Sealed for lifetime
Due to their manufacturing process, vacuum interrupters are proved to be "sealed for lifetime". This avoids the need for monitoring systems or tightness tests as stated in the IEEE std C37.100.1 on paragraph 6.8.3.
Overvoltage effects
Under certain circumstances, the vacuum circuit breaker can force the current in the circuit to zero before the natural zero (and reversal of current) in the alternating-current circuit. If interrupter operation timing is unfavorable with respect to the AC-voltage waveform (when the arc is extinguished but the contacts are still moving and ionization has not yet dissipated in the interrupter), the voltage may exceed the gap's withstand voltage. This can re-ignite the arc, causing abrupt transient currents. In either case, oscillation is introduced into the system that may result in significant overvoltage. Vacuum-interrupter manufacturers address these concerns by selecting contact materials and designs to minimize current chopping. To protect equipment from overvoltage, vacuum switchgear usually includes surge arresters.
Nowadays, with very low current chopping, vacuum circuit breakers will not induce an overvoltage that could reduce insulation from surrounding equipment.
References
Electric power distribution
Electric power systems components
Electrical wiring
Safety switches | Vacuum interrupter | [
"Physics",
"Engineering"
] | 2,684 | [
"Electrical systems",
"Building engineering",
"Physical systems",
"Electrical engineering",
"Electrical wiring"
] |
53,258,521 | https://en.wikipedia.org/wiki/Monothalamea | "Monothalamea" is a grouping of foraminiferans, traditionally consisting of all foraminifera with single-chambered tests. Recent work has shown that the grouping is paraphyletic, and as such does not constitute a natural group; nonetheless, the name "monothalamea" continues to be used by foraminifera workers out of convenience.
Classification
"Monothalamea" traditionally contains two groups, neither of which is currently considered to be monophyletic:
"Allogromiida" traditionally consists of all foraminifera which lack a mineralised test, instead having a test of tectin. Recent work has shown that this grouping is paraphyletic.
"Astrorhizida" traditionally consists of all foraminifera with single-chambered, agglutinated tests. Recent work has shown that this grouping is polyphyletic, as agglutinated tests have evolved from proteinaceous tests multiple times throughout foraminiferal evolution.
Recent molecular evidence has revealed that the deep-sea xenophyophores are in fact agglutinated, single-chambered foraminifera. Molecular evidence has also revealed that the freshwater protist Reticulomyxa is in fact a naked, testless foraminifera, and as such it has been included with "monothalameans" in scientific discussion.
A 2013 molecular study using small subunit rDNA concluded that known "monothalameans" made up at least 22 distinct living clades from marine environments with an additional four clades from freshwater eDNA.
References
Further reading
Gubbay, S., Baker, M., Bettn, B., Konnecker, G. (2002). "The offshore directory: Review of a selection of habitats, communities and species of the north-east Atlantic", pp. 74–77.
NOAA Ocean Explorer. "Windows to the deep exploration: Giants of the protozoa", p. 2.
External links
Microscopy-UK: Note on Xenophyophores
More xenophyophore photos, with a map of their habitat
Foraminifera classes
Extremophiles
Taxa named by Ernst Haeckel | Monothalamea | [
"Biology",
"Environmental_science"
] | 459 | [
"Organisms by adaptation",
"Extremophiles",
"Environmental microbiology",
"Bacteria"
] |
53,258,862 | https://en.wikipedia.org/wiki/Leaf%20flushing | Leaf flushing or leaf out is the production of a flush of new leaves typically produced simultaneously on all branches of a bare plant or tree. Young leaves often have less chlorophyll and the leaf flush may be white or red, the latter due to presence of pigments, particularly anthocyanins. Leaf flushing succeeds leaf fall, and is delayed by winter in the temperate zone or by extreme dryness in the tropics. Leaf fall and leaf flushing in tropical deciduous forests can overlap in some species, called leaf-exchanging species, producing new leaves during the same period when old leaves are shed or almost immediately after. Leaf-flushing may be synchronized among trees of a single species or even across species in an area. In the seasonal tropics, leaf flushing phenology may be influenced by herbivory and water stress.
Red leaf flush
In tropical regions, leaves often flush red when young and in the phase of expansion to mature size. Red flushing is frequent among woody species, reported from 20 to 40% of the woody species in a site in Costa Rica, in 36% of species in Barro Colorado Island, Panama, about 49% of species in Kibale National Park, Uganda, and in 83 of 250 species in Southern Yunnan, China. The red coloration is primarily due to the presence of anthocyanins. Various hypotheses have been advanced to explain red flushing. The herbivore defense hypothesis suggests that the red coloration may make the leaves less likely to be attacked by insects as they are cryptic to herbivores that are blind to the red part of the spectrum. It has also been hypothesised that the anthocyanins may reduce light stress or fungal attacks on leaves. A recent study in tropical forest region of China provides support for the herbivore defense hypothesis, indicating that the red coloration of young leaves protects them from attacks of herbivorous insects through chemical defense as the red leaves have high concentrations of tannins and anthocyanins.
References
Botany
Periodic phenomena | Leaf flushing | [
"Biology"
] | 413 | [
"Plants",
"Botany"
] |
53,259,964 | https://en.wikipedia.org/wiki/Greedy%20triangulation | The Greedy Triangulation is a method to compute a polygon triangulation or a Point set triangulation using a greedy schema, which adds edges one by one to the solution in strict increasing order by length, with the condition that an edge cannot cut a previously inserted edge.
References
Triangulation (geometry)
Optimization algorithms and methods | Greedy triangulation | [
"Mathematics"
] | 71 | [
"Triangulation (geometry)",
"Planes (geometry)",
"Planar graphs"
] |
51,709,740 | https://en.wikipedia.org/wiki/Senior%20cat%20diet | A senior cat diet is generally considered to be a diet for cats that are mature (7–10 years old), senior (11–15 years old), or geriatric (over 15 years old). Nutritional considerations arise when choosing an appropriate diet for a healthy senior cat. Dietary management of many conditions becomes more important in senior cats because changes in their physiology and metabolism may alter how their system responds to medications and treatments.
Energy and macronutrient requirements
Diets should be managed for each individual cat to ensure that they maintain an ideal body and muscle condition. Unlike many other species, the energy requirements for cats do not decrease with age, but may even increase, therefore seniors require the same or more energy than adults.
Scientific studies have indicated that after 12 years of age, and again after 13 years of age, energy requirements for cats increase significantly.
Obesity is common in adult cats, but much less so in senior cats. Of all feline life stages it has been demonstrated that senior cats are the most often underweight.
Research has shown that fat and protein digestibility decrease with age in cats, causing seniors to have a higher dietary requirement for these macronutrients. The fat and protein sources need to be highly digestible to maximize energy capture from the food. This may help to explain the body condition differences between adult and senior cats given the consistency of food intake.
There is little research on the reasons for decreased fat and protein digestibility, however some speculations have been made based on age-related changes observed in other species. Decreased secretion of digestive enzymes may be related to decreased digestive function in humans and rats, however more research into this is required to explain this in cats. Vitamin B12 is important in methionine synthesis, DNA synthesis, and is a vital part of an enzyme important for metabolic pathways. Lower nutrient digestibility may be due to gastrointestinal disease, including pancreatic and intestinal disease, which are often found with low levels of vitamin B12. One study has shown that fat digestibility in senior cats could be reduced by as much as 9% when associated with B12 deficiency and pancreatic disease.
Due to this lower digestibility seen in seniors, it is important to look at metabolizable energy values, which provide a more accurate assessment of nutrient availability than a gross energy calculation. The metabolizable energy of food is determined by the Atwater system and calculates the amount of energy available to the animal after digestion and absorption. A gross energy calculation may overestimate digested energy, as it provides the total available energy in the food rather than what is actually being utilized by the cat.
Age-related disorders and dietary considerations
Senior cats are often prone to arthritis, periodontal disease, and a decline in cognitive and sensory function.
What an owner may perceive as a normal age-related change could actually be subtle signs of arthritis, such as increased inactivity and reluctance to perform normal activities, such as stair climbing and descent. Arthritis has been found in approximately 80-90% of senior cats showing little or no lameness; in many cases this is not a result of damage to the joints but natural degeneration specific to cats. Cats that suffer from arthritis have been shown in some studies to display significant signs of improvement when chondroprotectants, substances which help maintain the integrity of connective tissue, are added to the diet. Evidence for antioxidants (vitamin C and E, and beta-carotene), omega-3 fatty acids such as eicosapentaenoic acid (f) and docosahexaenoic acid (DHA) for inflammation, Lcarnitine and lysine has been shown to be beneficial in other species.
Cognitive decline similar to that seen in humans and dogs has been observed in senior cats, with ongoing research into the causes and treatment. Changes in the structure of the brain, including those similar to the causes of Alzheimer's disease in humans, are considered to be a significant factor in cognitive issues in cats. Studies in other species have shown that supplementing dietary omega-3 and -6 fatty acids, particularly EPA, DHA, and arachidonic acid, along with antioxidants such as beta-carotene and vitamin B12, may aid in the prevention of decline of cognitive function, and slow the progression of symptoms.
Senior cats tend to become particularly picky with their food as a reduced ability to taste and smell is associated with age, therefore, palatability is an important factor to consider. Cats have shown a preference in studies for diets with a higher protein content regardless of the flavouring of the food. Additionally, cats are unable to effectively regulate their water intake, and seniors are particularly prone to dehydration. Wet diets should be considered to increase water intake and enhance palatability, as well as to alleviate discomfort associated with periodontal disease, a common concern with senior cats. Dry dental kibble could be considered to help prevent plaque buildup on teeth, however as this has only been shown to be effective as the sole diet, brushing of the teeth or dental chews would be a better alternative in combination with a canned food in order to optimize water intake, palatability and dental health.
Holistic guidance
As they do not digest as much energy per meal as an adult cat, it is important to feed senior cats smaller, more frequent meals of a highly digestible diet throughout the day. It is also important to monitor the cat's health closely, with regular visits to the veterinarian, as they are very good at hiding symptoms of disease. By carefully selecting a diet that considers a senior cat's changing needs, such as digestion, mobility, cognition, dental health and body condition, it may be possible to manage, or even prevent the progression of many of these age associated conditions.
References
Cat health
Cats as pets
Pet foods
Senescence in non-human organisms | Senior cat diet | [
"Biology"
] | 1,220 | [
"Senescence",
"Senescence in non-human organisms"
] |
51,709,781 | https://en.wikipedia.org/wiki/Antivector | An antivector is an element of grade in an n-dimensional exterior algebra. An antivector is always a blade, and it gets its name from the fact that its components each involve a combination of all except one basis vector, thus being the opposite of a vector whose components each involve exactly one basis vector. Like a vector, an antivector has n components in n-dimensional space, and this sometimes leads to an inadequate distinction being made between the two types of entities. However, antivectors transform differently with a change of basis than vectors do, which shows that they are different kinds of quantities.
In physics, the names pseudovector and axial vector are used to describe vectors that transform in the same way that an antivector transforms. These typically arise as the result of cross products between two vectors.
See also
Exterior algebra
Geometric algebra
References
Multilinear algebra | Antivector | [
"Mathematics"
] | 179 | [
"Algebra stubs",
"Algebra"
] |
51,709,901 | https://en.wikipedia.org/wiki/OGLE-2007-BLG-349%28AB%29b | OGLE-2007-BLG-349(AB)b is a circumbinary extrasolar planet about 8,000 light-years away in the constellation of Sagittarius. It is the first circumbinary exoplanet to be discovered using the microlensing method of detecting exoplanets.
Characteristics
Mass and orbit
OGLE-2007-BLG-349L(AB)b is a super-Neptune, an exoplanet that has a mass and radius larger than that of Neptune. It has a mass of around 80 . This is somewhat close to the mass of Saturn, 95 , so OGLE-2007-BLG-349L(AB)b can also be considered a gas giant. It orbits at a distance of around 2.9 AU in a circumbinary orbit, meaning it orbits around two stars.
Host star
The planet orbits in a circumbinary (M-type) binary star system named OGLE-2007-BLG-349L. They orbit around each other roughly every 9 days. The stars have masses of 0.41 and 0.30 , respectively. The age of the system, radii and temperatures of the stars are not known. In comparison, the Sun is 4.6 billion years old and has a surface temperature of 5778 K. The star's apparent magnitude, or how bright it appears from Earth's perspective, is 14.3. Therefore, it is too dim to be seen with the naked eye.
See also
Optical Gravitational Lensing Experiment (OGLE)
47 Ursae Majoris b
OGLE-2005-BLG-390Lb
OGLE-2006-BLG-109Lb
Notes
References
External links
OGLE-2007-BLG-349 AB c at the NASA Exoplanet Archive
Sagittarius (constellation)
Exoplanets discovered in 2016
Giant planets
Exoplanets detected by microlensing | OGLE-2007-BLG-349(AB)b | [
"Astronomy"
] | 415 | [
"Sagittarius (constellation)",
"Constellations"
] |
51,711,705 | https://en.wikipedia.org/wiki/Approximate%20measures | Approximate measures are units of volumetric measurement which are not defined by a government or government-sanctioned organization, or which were previously defined and are now repealed, yet which remain in use.
It may be that all English-unit derived capacity measurements are derived from one original approximate measurement: the mouthful, consisting of about ounce, called the ro in ancient Egypt (their smallest recognized unit of capacity). The mouthful was still a unit of liquid measure during Elizabethan times. (The principal Egyptian standards from small to large were the ro, hin, hekat, and khar.)
Because of the lack of official definitions, many of these units will not have a consistent value.
United Kingdom
glass-tumbler
breakfast-cup
tea-cup
wine-glass
table-spoon
dessert-spoon
tea-spoon
black-jack
demijohn (dame-jeanne)
goblet
pitcher
gyllot (about equal to 1/2 gill)
noggin (1/4 pint)
nipperkin (measure for liquor, containing no more than 1/2 pint)
tumblerful (10 fl oz or 2 gills or 2 teacupsful)
apothecaries' approximate measures
teacupful = about 4 fl oz
wineglassful = about 2 fl oz
tablespoonful = about 1/2 fl oz
dessertspoonful = about 2 fl dr
teaspoonful = about 1 fl dr
drop = about minim
teacupful (5 fl oz, or 1 gill ibid)
wineglassful (2-1/2 fl oz or 1/2 gill or 1/2 teacupful or 1/4 tumblerful)
dessertspoonful (1/4 fl oz or 2 fl dr and equal to 2 teaspoonful or 1/2 tablespoonful)
teaspoonful (1/8 fl oz or 1 fl dr and also equal to 1/2 dessertspoonful or 1/4 tablespoonful)
United States
The vagueness of how these measures have been defined, redefined, and undefined over the years, both through written and oral history, is best exemplified by the large number of sources that need to be read and cross-referenced in order to paint even a reasonably accurate picture. So far, the list includes the United States Pharmacopoeia, U.S. FDA, NIST, A Manual of Weights, Measures, and Specific Gravity, State Board Questions and Answers, MediCalc, MacKenzie's Ten Thousand Receipts, Approximate Practical Equivalents, When is a Cup not a Cup?, Cook's Info, knitting-and.com., and Modern American Drinks.
Dashes, pinches, and smidgens are all traditionally very small amounts well under a teaspoon, but not more uniformly defined. In the early 2000s some companies began selling measuring spoons that defined a dash as teaspoon, a pinch as teaspoon, and a smidgen as teaspoon. Based on these spoons, there are two smidgens in a pinch and two pinches in a dash. However, the 1954 Angostura “Professional Mixing Guide” states that “a dash” is 1/6th of a teaspoon, or 1/48 of an ounce, and Victor Bergeron (a.k.a. Trader Vic, famous saloonkeeper), said that for bitters it was teaspoon, but fl oz for all other liquids.
References
Measurement | Approximate measures | [
"Physics",
"Mathematics"
] | 706 | [
"Quantity",
"Physical quantities",
"Measurement",
"Size"
] |
51,713,731 | https://en.wikipedia.org/wiki/Tongguan%20Kiln | The Tongguan Kiln (), also called the Changsha Kiln, is located in Wazhaping (), Tongguan Subdistrict, Changsha, Hunan, China. It is one of the major kiln sites in Tongguan to be protected at the national level. The place was a historical kiln site of potteries in the Tang (618–907 AD) and Five Dynasties periods (907–960 AD).
The site covers about 68 hectares and found in 1956, it was the source place of underglaze by the Palace Museum's identification in 1957. The place was published one of the Major Historical and Cultural Sites Protected at the National Level by the State Council in January 1988, and was classified as one of the 100 Great Sites Protection Plan from 2006.
References
Bibliography
Chinese pottery kiln sites
History of Changsha
Wangcheng District
Major National Historical and Cultural Sites in Hunan
National archaeological parks of China
Tourist attractions in Changsha
1956 archaeological discoveries | Tongguan Kiln | [
"Chemistry",
"Engineering"
] | 202 | [
"Chinese pottery kiln sites",
"Kilns"
] |
51,714,214 | https://en.wikipedia.org/wiki/Discovery%20and%20development%20of%20direct%20Xa%20inhibitors | Four drugs from the class of direct Xa inhibitors are marketed worldwide. Rivaroxaban (Xarelto) was the first approved FXa inhibitor to become commercially available in Europe and Canada in 2008. The second one was apixaban (Eliquis), approved in Europe in 2011 and in the United States in 2012. The third one edoxaban (Lixiana, Savaysa) was approved in Japan in 2011 and in Europe and the US in 2015. Betrixaban (Bevyxxa) was approved in the US in 2017.
History
Heparin
Heparin was discovered by Jay McLean and William Henry Howell in 1916, it was first isolated from a canine liver, which in Greek translates to hepar. Heparin targets multiple factors in the blood coagulation cascade, one of them being FXa. At first, it had many side effects but for the next twenty years, investigators worked on heparin to make it better and safer. It entered clinical trials in 1935 and the first drug was launched in 1936. Chains of natural heparin can vary from 5.000 to 40.000 daltons. In the 1980s Low molecular weight heparin (LMWH) were developed and they only contain chains with an average molecular weight of less than 8.000 Da.
Warfarin
In the 1920s there was an outbreak of a mysterious haemorrhagic cattle disease in Canada and the northern United States. The disease was named sweet clover disease because the cattle had grazed on sweet clover hay. It wasn't until ten years after the outbreak, that a local investigator, Karl P. Link and his student Wilhelm Schoeffel started an intense investigation to find the substance causing the internal bleeding. It took them 6 years to discover dicoumarol, the causing agent. They patented the right for the substance and in 1945 Link started selling a coumarin derivative as a rodenticide. He and his colleagues worked on several variations and ended up with a substance they named warfarin in 1948. It wasn't until 1954 that it was approved for medicinal use in humans making warfarin the first oral anticoagulant drug.
Need for newer and better oral drugs
Warfarin treatment requires blood monitoring and dose adjustments regularly due to its narrow therapeutic window. If supervision isn't adequate warfarin poses a threat in causing, all too frequent, haemorrhagic events and multiple interactions with food and other drugs. Currently, the main problem with low molecular weight heparin (LMWH) is the administration route, as it has to be given subcutaneously. Because of these disadvantages there has been an urgent need for better anticoagulant drugs. For a modern society, convenient and fast drug administration is the key to a good drug compliance. In 2008 the first direct Xa inhibitor was approved for clinical use. Direct Xa inhibitors are just as efficacious as LMWH and warfarin but they are given orally and don't need as strict monitoring. Other Xa inhibitors advantages are rapid onset/offset, few drug interactions and predictable pharmacokinetics. The rapid onset/offset effect greatly reduces the need for “bridging” with parenteral anticoagulants after surgeries. Today there are four factor Xa inhibitors marketed: rivaroxaban, apixaban, edoxaban and betrixaban.
Antistasin and tick anticoagulant peptide (TAP)
Factor Xa was identified as a promising target for the development of new anticoagulants in the early 1980s. In 1987 the first factor Xa inhibitor, the naturally occurring compound antistasin, was isolated from the salivary glands of the Mexican leech Haementeria officinalis. Antistasin is a polypeptide and a potent Xa inhibitor. In 1990 another naturally occurring Xa inhibitor was isolated, tick anticoagulant peptide (TAP) from extracts of the tick Ornithodoros moubata. TAP and antistasin were used to estimate factor Xa as a drug target.
Mechanism of action
Blood coagulation is a complex process by which the blood forms clots. It is an essential part of hemostasis and works by stopping blood loss from damaged blood vessels. At the site of injury, where there is an exposure of blood under the endothelium, the platelets gather and immediately form a plug. That process is called primary hemostasis. Simultaneously, a secondary hemostasis occurs. It is defined as the formation of insoluble fibrin by activated coagulation factors, specifically thrombin. These factors activate each other in a blood coagulation cascade that occurs through two separate pathways that interact, the intrinsic and extrinsic pathway. After activating various proenzymes, thrombin is formed in the last steps of the cascade, it then converts fibrinogen to fibrin which leads to clot formation. Factor Xa is an activated serine protease that occupies a key role in the blood coagulation pathway by converting prothrombin to thrombin. Inhibition of factor Xa leads to antithrombotic effects by decreasing the amount of thrombin. Directly targeting factor Xa is suggested to be an effective approach to anticoagulation.
Development
In 1987 antistasin was tested as the first direct Xa inhibitor. Antistasin is a protein made up of 119 amino acid residues, of which 20 are cysteines involved in 10 disulfide bonds. It acts as a slow, tight-binding inhibitor of factor Xa with a Ki value of 0.3–0.6 nM but it also inhibits trypsin. Recombinant Antistasin can be produced by genetically modified yeast, saccharomyces cerevisiae. Another natural occurring direct Xa-inhibitor, the tick anticoagulant peptide (TAP), was discovered in 1990. It is a single-chain, 60 amino acid peptide and like antistasin it is a slow, tight-binding inhibitor with a similar Ki value (~0.6 nM).
These two proteins were mostly used to validate factor Xa as a drug target. Animal studies suggested direct Xa-inhibition to be a more efficient approach to anticoagulation compared to direct thrombin inhibitors, especially offering a wider therapeutic window and reducing the risk of rebound thrombosis, (increase in thromboembolic events occurring shortly after the withdrawal of an antithrombotic medication) compared to direct and indirect thrombin inhibitors.
During the 1990s several low-molecular-weight substances were developed, such as DX-9065a and YM-60828.
DX-9065a was the first synthetic compound that inhibited FXa without inhibiting thrombin. That was attained by inserting a carboxyl group which seemed to be the most important moiety for a selective binding to FXa. Those early developed small molecules yet had amidine-groups or even higher-basic functions, which were thought to be necessary as mimics for an arginine residue in prothrombin, the natural substrate of factor Xa. Nevertheless, these basic functions are also related to a very poor oral bioavailability (e.g. 2–3% for DX-9065a).
In 1998 Bayer Healthcare, a pharmaceutical company started searching for low-molecular-weight direct factor Xa inhibitors with higher oral bioavailability. High-throughput screening and further optimisation at first lead to several substances from the class of isoindolinones demonstrating that much less basic substances can also act as potent Xa inhibitors to an IC50 value of up to 2 nM. Although isoindolinones have a better oral bioavailability than the original compounds it was insufficient. However, the project later lead to the class of n-aryloxazolidinones that provides substances with both high potency of inhibiting factor Xa and high bioavailability. One compound of this class, Rivaroxaban (IC50 = 0.7 nM, bioavailability: 60%), was granted marketing authorization for the prevention of venous thromboembolism in Europe and Canada in September 2008.
Chemistry
Factor Xa: Structure and binding sites
Factors IIa, Xa, VIIa, IXa and XIa are all proteolytic enzymes that have a specific role in the coagulation cascade. Factor Xa (FXa) is the most promising one due to its position at the intersection of the intrinsic and extrinsic pathway as well as generating around 1000 thrombin molecules for each Xa molecule which results in a potent anticoagulant effect. FXa is generated from FX by cleavage of a 52 amino acid activation peptide, as the "a" in factor Xa means activated. FXa consists of 254 amino acid catalytic domain and is also linked to a 142 amino acid light chain. The chain contains both GLA domain and two epidermal growth factor domains (EGF like domains).
The active site of FXa is structured to catalyze the cleavage of physiological substrates and cleaves PhePheAsnProArg-ThrPhe and TyrIleAspGlyArg-IleVal in prothrombin. FXa has four so-called pockets which are targets for substrates to bind to factor Xa. These pockets are lined up by different amino acids and Xa inhibitors target these pocket when binding to factor Xa. The two most relevant pockets regarding affinity and selectivity for the Xa inhibitors are S1 and S4.
S1: The S1 pocket is a hydrophobic pocket and contains an aspartic acid residue (Asp-189) which can serve as a recognition site for a basic group. FXa has a residual space in the S1 pocket and is lined by residues Tyr-228, Asp-189 and Ser-195.
S2: The S2 pocket is a small and shallow pocket. It merges with the S4 pocket and has room for small amino acids. Tyr-99 seems to block access to this pocket, so this pocket is not as important as S1 and S4.
S3: The S3 pocket is located on the rim of the S1 pocket and is flat and exposed to the solvent. This pocket is not as important as S1 and S4.
S4: The S4 pocket is hydrophobic in nature and the floor of the pocket is formed by Trp-215 residue. The residues Phe-174 and Tyr-99 of FXa join Trp-215 to form an aromatic box that is able to bind aliphatic, aromatic and positively charged fragments. Because of the binding to positively charged entities, it can be described as a cation hole.
Chemical structure and properties of direct Xa inhibitors
Binding of Xa inhibitors to factor Xa
The Xa inhibitors all bind in a so-called L-shape fashion within the active site of factor Xa. The key constituents of the factor Xa are the S1 and S4 binding sites. It was first noted that the natural compounds, antistasin and TAP, which possess highly polar and therefore charged components bind to the target with some specificity. That's why newer drugs were designed with positively charged groups but those resulted in poor bioavailability. Nowadays marketed Xa inhibitors, therefore contain an aromatic ring with various moieties attached for different interactions with the S1 and S4 binding sites. This also ensures good bioavailability as well as maintaining firm binding strength. The Xa inhibitors currently on market today, therefore rely on hydrophobic and hydrogen bonding instead of highly polar interactions.
Antistasin binding to factor Xa
Antistasin contains an N- and a C-terminal domain which are similar in their amino acid sequences with ~40% identity and ~56% homology. Each of them contains a short β-sheet structure and 5 disulfide bonds. Only the N-terminal domain is necessary to inhibit Xa while the C-terminal domain does not contribute to the inhibitory properties due to differences in the 3 dimensional structure, even though the C-terminal domain has a strongly analogue pattern to the actual active site.
The interaction of antistasin with FXa involves both the active site and the inactive surface of FXa. The reactive site of antistasin formed by Arg-34 and Val-35 in the N-terminal domain suits the binding site of FXa, most likely the S1 pocket. At the same time, Glu-15 located outside the reactive site of antistasin fits to positively charged residues on the surface of FXa. The multiple binding is thermodynamically advantageous and leads to sub-nanomolar inhibition (Ki = 0.3–0.6 nM).
DX-9065a binding to factor Xa
DX-9065a, the first small molecule direct Xa-inhibitor, is an amidinoaryl derivate with a molecular weight of 571.07g/mol. Its positively charged amidinonaphtalene group forms a salt bridge to the Asp-189 residue in the S1 pocket of FXa. The pyrrolidine ring fits between Tyr-99, Phe-174 and Trp-215 in the S4 pocket of FXa.
Unlike older drugs, e.g. heparin, DX-9065a is selective for FXa compared to thrombin even though FXa and thrombin are similar in their structure. This is caused by a difference in the amino acid residue in the homologue position 192. While FXa has a glutamine residue in that position, thrombin has a glutamic acid that causes electrostatic repulsion with the carboxyl group of DX-9065a. In addition, a salt bridge between Glu-97 of thrombin and the amidine group fixed in the pyrrolidine ring of DX-9065a reduces the flexibility of the DX-9065a molecule, which now cannot rotate enough to avoid the electrostatic clash. That's why the IC50 value for thrombin is >1000μM while the IC50 value for FXa is 0.16μM.
Rivaroxaban binding to factor Xa
Rivaroxaban binding to FXa is mediated through two hydrogen bonds to the amino acid Gly-219. These two hydrogen bonds serve an important role directing the drug into the S1 and S4 subsites of FXa. The first hydrogen bond is a strong interaction which comes from the carbonyl oxygen of the oxazolidinone core of rivaroxaban. The second hydrogen bond is a weaker interaction and comes from the amino group of the clorothiophene carboxamide moiety.
These two hydrogen bonds result in the drug forming an L-shape and fits in the S1 and S4 pockets. The amino acids residues Phe-174, Tyr-99, and Trp-215 form a narrow hydrophobic channel that is the S4 binding pocket. The morpholinone part of rivaroxaban is “sandwiched” between amino acids Tyr-99 and Phe-174 and the aryl ring of rivaroxaban is oriented perpendicularly across Trp-215. The morpholinone carbonyl group does not have a direct interaction to the FXa backbone, instead, it contributes to a planarization of the morpholinone ring and therefore supports rivaroxaban to be sandwiched between the two amino acids.
The interaction between the chlorine substituent of the thiophene moiety and the aromatic ring of Tyr-228, which is located at the bottom of the S1, it is very important due to the fact that it obviates the need for strongly basic groups for high affinity for FXa. This enables rivaroxaban, which is non-basic, to achieve good oral bioavailability and potency.
Apixaban binding to factor Xa
Apixaban shows a similar binding mode as rivaroxaban and forms a tight inhibitor-enzyme complex when connected to FXa. The p-methoxy group of apixaban connects to S1 pocket of FXa but does not appear to have any interaction with any residues in this region of FXa. The pyrazole N-2 nitrogen atom of apixaban interacts with Gln-192 and the carbonyl oxygen interacts with Gly-216. The phenyl lactam group of apixaban is positioned between Tyr-99 and Phe-174 and due to its orientation, it is able to interact with Trp-215 of the S4 pocket. The carbonyl oxygen group of the lactam moiety interacts with a water molecule and does not seem to interact with any residues in the S4 pocket.
Structure-activity-relationship (SAR)
An important part of designing a compound, that is an ideal inhibitor to a certain target, is to understand the amino acid sequence of the target site for the compound to bind to. Modelling both prothrombin and FXa makes it possible to deduct the difference and identify the amino acids at each binding site. At the bottom of the S1 pocket on FXa the binding amino acid is Asp-189 which amidine moieties can bind to. After X-raying the binding site of FXa, it was revealed that the S1 pocket had a planar shape, meaning that a flat amidinoaryl group should bind to it without steric hindrance.
Modern direct Xa inhibitors are L-shaped molecules whose ends fit perfectly in the S1 and S4 pockets. The long side of the L-shape has to conform to a highly-specific tunnel within the targets active site. To accomplish that, this part of the molecules is designed to have little formal interactions with FXa in that region. As there is no specific bonding, the fit of these agents between the pockets of FXa increases the total specificity of the drugs to the FXa molecule. The interaction between the S1 pocket of FXa and the inhibitor can be both ionic or non-ionic, which is important because it allows the design of the moiety to be adjusted to increase oral bioavailability. Previously designed compounds were charged molecules that are not absorbed well in the gastrointestinal tract and therefore did not reach high serum concentrations. The newer drugs have a better bioavailability as they are not charged and have a non-ionic interaction to the S1 pocket.
Rivaroxaban
During the SAR development of rivaroxaban, researchers realized that adding a 5-chlorothiophene-2-carboxamide group to the oxazolidonine core could increase the potency by 200 fold, which had previously been too weak for medical use. In addition to this discovery, a clear preference for the (S)-configuration was confirmed. This compound had a promising pharmacokinetical profile and did not contain a highly basic amidine group, but that had previously been considered important for the interaction with the S1 pocket. These findings lead to extensive SAR (structure-activity relationship) researches. During the SAR testing, R1 was defined as the most important group for potency. Pyrrolidinone was the first R1 functional group to significantly increase the potency but further researches revealed even higher potency with a morpholinone group instead. Groups R2 and R3 had hydrogen or fluorine attached and it was quickly assessed that having hydrogen resulted in highest potency. Groups R2 and R3 were then substituted for various groups, which were all less potent than the hydrogen, so hydrogen was the final result. As the chlorothiophene moiety had an inadequate water solubility, substituting it with another group was attempted but was unsuccessful. The chlorothiophene moiety binds to Tyr-228 at the bottom of the S1 pocket, making it a key factor regarding binding to FXa. Rivaroxaban has both high affinity and good bioavailability.
Apixaban
During the SAR development of apixaban there were three groups that needed to be tested to attain maximum potency and bioavailability. The first group to be tested was the non-active site as it needs to be stabilized before SAR testing on the p-methoxyphenyl group (S1 binding moiety). There are several of groups that increase the potency of the compound, mostly amides, amines and tetrazoles but also methylsulfonyl and trifluoromethyl groups. Of these groups, carboxamide has the greatest binding and had similar clotting activity as the compounds.
In dog testing, this compound with a carboxamide group called 13F, showed a great pharmacokinetical profile, a low clearance and adequate half-life and volume of distribution. Due to the success of finding a stabilizing group, SAR research for S1 binding moiety (p-methoxyphenyl) was discontinued. In the S4 binding group, N-methylacetyl and lactam analogues proved to have a very high binding affinity for FXa, showed great clotting and selectivity versus other proteases. Orientation turned out to be important as N-methyl acetyl, compared to acetamide, had a 300 fold lower binding ability to FXa due to unfavorable planarity close to the S4 region binding site.
Synthesis
Rivaroxaban
Rivaroxaban chemically belongs to the group of n-aryloxazolidinones. Other drugs of that group are linezolid and tedizolid, both of whom are antibiotics. A synthesis of n-aryloxazolidinones starting with an O-silyl protected ethyl(2,3-dihydroxypropyl)-carbamate was published in 2016. In a one-pot reaction the carbamate cyclisizes to a 2-oxazolidone ring under slightly basic conditions while simultaneously the oxazolidone nitrogen is arylized by copper-catalization. For rivaroxaban in particular, 3-morpholinone substitutes the iodine in p-position of the benzene ring by copper-catalization. Afterwards, the silyl protecting group is removed and the resulting alcohol is replaced by an amino group which is then acylated in the last step.
An industrial preparation of rivaroxaban was registered as a patent by Bayer Healthcare in 2005. It starts from N-(4-aminophenol)-morpholinone which is alkylated by a propylene oxide derivate that also contains a primary amine involved in a phthalimide protection group. Next, a phosgene equivalent is added to form the 2-oxazolidone ring and the phthalimide is removed. The free amine can now be acylated which leads to rivaroxaban.
However, according to the patent the synthesis has “various disadvantages in the reaction management which has particularly unfavourable effects for preparation“. The patent also explains another synthesis starting from a chlorothiophene derivate that would be more suitable for the industrial process but points out that toxic solvents or reagents have to be removed from the final product. Therefore, this way is not an alternative.
Various other synthesis pathways of rivaroxaban have been described.
Apixaban
The first full synthesis of apixaban was published in 2007. The key step of this reaction is a (3+2)cycloaddition of a p-methoxyphenylchlorohydrazon derivate and a p-iodophenyl-morpholin-dihydropyridin derivate. After the following elimination of HCl and morpholine, the iodine is substituted by 2-piperidinone by copper-catalization and the ethyl esther is converted to an amide (aminolysis). This reaction was registered as a patent in 2009.
Clinical use
Direct factor Xa inhibitors are being used clinically and their usage is constantly increasing. They are gradually taking over warfarin usage and low molecular weight heparins (LMWH). Indication for Xa inhibitors is preventing deep vein thrombosis (DVT) which can lead to pulmonary embolism. It is also used to treat atrial fibrillation to lower the risk of stroke caused by a blood clot. Another indication is a prophylactic treatment for blood clotting (thrombosis) due to atherosclerosis. Rivaroxaban was the first FXa inhibitor on the market and then followed by apixaban, edoxaban and betrixaban.
Pharmacokinetics
Future perspectives
Direct Xa inhibitors in clinical trials
Rivaroxaban, apixaban, edoxaban and betrixaban are already on the market. As of October 2016, several new direct Xa inhibitors have entered clinical trials. These are letaxaban from Takeda and eribaxaban from Pfizer.
Antidotes
Andexxa (Andexanet alfa) from Portola Pharmaceuticals is a recombinant protein that is given intravenously. It works as an antidote to all direct and indirect FXa inhibitors. Andexxa acts as a decoy receptor for Xa inhibitors.
References
Direct Xa inhibitors
Drug discovery | Discovery and development of direct Xa inhibitors | [
"Chemistry",
"Biology"
] | 5,368 | [
"Life sciences industry",
"Medicinal chemistry",
"Drug discovery"
] |
51,714,373 | https://en.wikipedia.org/wiki/ASIC5 | ASIC5 gene is one of the five paralogous genes that encode proteins that form trimeric Acid-sensing ion channels (ASICs) in mammals. Aliases previously used for this gene include ACCN5 and BASIC. The protein encoded by this gene does not appear to be acid responsive. The cDNA coding for this protein was first characterized in 2000. The ASIC genes have splicing variants that encode different proteins that are called isoforms.
These genes are mainly expressed in the central and peripheral nervous system.
ASICs can form both homotrimeric (meaning composed of three identical subunits) and heterotrimeric channels.
Structure and function
This gene encodes a member of the ASIC/ENaC superfamily of proteins. The members of this family are amiloride-sensitive sodium channels that contain intracellular N and C termini, 2 hydrophobic transmembrane (TM) regions, and a large extracellular loop, which has many cysteine residues with conserved spacing. The TM regions are generally symbolized as TM1 (clone to N-terminus) and TM2 (close to C-terminus).
The pore of the channel through which ions selectively flow from the extracellular side into the cytoplasm is formed by the three TM2 regions of the trimer.
References
Further reading
Ion channels
Human proteins | ASIC5 | [
"Chemistry"
] | 283 | [
"Neurochemistry",
"Ion channels"
] |
51,714,844 | https://en.wikipedia.org/wiki/George%20Henslow | George Henslow (23 March 1835, Cambridge, UK – 30 December 1925, Bournemouth) was an Anglican curate, botanist and author. Henslow was notable for being a defender of Lamarckian evolution.
Biography
The third son of Rev. John Stevens Henslow, George Henslow was educated at King Edward VI School, Bury St Edmunds and then matriculated on 30 May 1854 at Christ's College, Cambridge, where he graduated B.A. 1858 and M.A. 1861. He was ordained in the Church of England a deacon in 1859 and a priest in 1861. In 1864, he became a Fellow of the Linnean Society. He was the headmaster from 1861 to 1864 of Hampton Lucy Grammar School and from 1865 to 1872 of the Grammar School, Store Street, London. From 1868 to 1880, he was Lecturer in Botany at St Bartholomew's Hospital and also at Birkbeck College and Queen's College, London. He was from 1868 to 1870 Curate of
St John's Wood Chapel and from 1870 to 1887 Curate of St James's, Marylebone. He resided at Ealing, where he was from 1882 to 1904 President of the Ealing Microscopical and Natural History Society, then resided at Drayton House in Learnington and finally at Bournemouth. On 26 October 1897, he was among the first 60 medallists of the Victoria Medal of Honour awarded by the Royal Horticultural Society.
He married in Cambridge on 13 October 1859 to Ellen Weekley (c. 1836–1875) but they divorced on 8 July 1872. In St Pancras, London in the 4th registration quarter of 1872, he married Georgina Brook Bailey (1843–1876). In 1881, he married his third wife Katharine Yeo (c. 1845–1919), the widow of Reverend Yeo of Ealing. George Henslow's third wife brought step-children to his third marriage but bore no more children. There were five children from his first marriage but only one, George Stevens Henslow (1863–1924), survived to adulthood. Henslow died on 30 December 1925 in Bournemouth.
In his later years, he became a believer in spiritualism.
Evolution
Henslow was a proponent of theistic evolution who held that "natural selection plays no part in the origin of species." He promoted his Lamarckian theory of evolution in plants by direct adaptation, known as "the True Darwinism".
He used this term in opposition to Neo-Darwinism, which denied the inheritance of acquired characteristics.
Selected publications
Articles
Books
References
External links
1835 births
1925 deaths
19th-century English Anglican priests
19th-century English writers
20th-century English Anglican priests
20th-century English writers
Alumni of Christ's College, Cambridge
English botanists
English spiritualists
Lamarckism
British parapsychologists
Parson-naturalists
Theistic evolutionists
Victoria Medal of Honour recipients | George Henslow | [
"Biology"
] | 577 | [
"Obsolete biology theories",
"Biology theories",
"Lamarckism",
"Non-Darwinian evolution",
"Theistic evolutionists"
] |
51,715,905 | https://en.wikipedia.org/wiki/Dhanusha%20%28unit%29 | Dhanusha is an ancient unit of measuring height used in Jain literature.
Modern units
One Dhanusha equals 3 meters.
References
Units of measurement | Dhanusha (unit) | [
"Mathematics"
] | 31 | [
"Quantity",
"Units of measurement"
] |
51,716,359 | https://en.wikipedia.org/wiki/Haar%20space | In approximation theory, a Haar space or Chebyshev space is a finite-dimensional subspace of , where is a compact space and either the real numbers or the complex numbers, such that for any given there is exactly one element of that approximates "best", i.e. with minimum distance to in supremum norm.
References
Approximation theory | Haar space | [
"Mathematics"
] | 75 | [
"Mathematical analysis",
"Mathematical analysis stubs",
"Approximation theory",
"Mathematical relations",
"Approximations"
] |
51,717,116 | https://en.wikipedia.org/wiki/Bass%E2%80%93Quillen%20conjecture | In mathematics, the Bass–Quillen conjecture relates vector bundles over a regular Noetherian ring A and over the polynomial ring . The conjecture is named for Hyman Bass and Daniel Quillen, who formulated the conjecture.
Statement of the conjecture
The conjecture is a statement about finitely generated projective modules. Such modules are also referred to as vector bundles. For a ring A, the set of isomorphism classes of vector bundles over A of rank r is denoted by .
The conjecture asserts that for a regular Noetherian ring A the assignment
yields a bijection
Known cases
If A = k is a field, the Bass–Quillen conjecture asserts that any projective module over is free. This question was raised by Jean-Pierre Serre and was later proved by Quillen and Suslin; see Quillen–Suslin theorem.
More generally, the conjecture was shown by in the case that A is a smooth algebra over a field k. Further known cases are reviewed in .
Extensions
The set of isomorphism classes of vector bundles of rank r over A can also be identified with the nonabelian cohomology group
Positive results about the homotopy invariance of
of isotropic reductive groups G have been obtained by by means of A1 homotopy theory.
References
Commutative algebra
Algebraic K-theory
Algebraic geometry | Bass–Quillen conjecture | [
"Mathematics"
] | 269 | [
"Fields of abstract algebra",
"Commutative algebra",
"Algebraic geometry"
] |
51,717,197 | https://en.wikipedia.org/wiki/Evamarie%20Hey-Hawkins | Evamarie Hey-Hawkins is a German inorganic chemist and professor at Leipzig University. Her research is focused on main group and transition metal chemistry.
Biography
She received her diploma (1982) and doctoral degree (1983) at the University of Marburg, Germany, with Kurt Dehnicke. After stays at the University of Sussex, UK (1984/85), the University of Western Australia (1985/86) and the ANU (1986/87), she returned to Germany and completed her habilitation in Marburg (1988). From 1988 to 1990 she was a research associate at the Max Planck Institute for Solid State Research, Stuttgart. Evamarie Hey-Hawkins has been a Full Professor of Inorganic Chemistry at Leipzig University, Germany, since 1993.
Research
Her scientific interests comprise many aspects of structural and synthetic chemistry. Much of her work focuses on main group compounds, especially phosphorus compounds. She has also conducted research on bioactive boron compounds. She has authored more than 540 publications in refereed journals.
References
External links
Website of The Hey-Hawkins Research Group at Leipzig University
Boron-Based Compounds: Potential and Emerging Applications in Medicine, ed. E. Hey-Hawkins and C. Viñas Teixidor, , Wiley, 2018.
Smart Inorganic Polymers: Synthesis, Properties and Emerging Applications in Materials and Life Sciences, ed. E. Hey-Hawkins, M. Hissler, , Wiley, 2019. (wiley.com)
20th-century German chemists
Inorganic chemists
Living people
German women chemists
Year of birth missing (living people)
Recipients of the Order of Merit of the Free State of Saxony
21st-century German chemists | Evamarie Hey-Hawkins | [
"Chemistry"
] | 337 | [
"Inorganic chemists"
] |
51,717,470 | https://en.wikipedia.org/wiki/Clear%20Labs | Clear Labs, Inc. is a private genomics testing company headquartered in San Carlos, California, United States. It offers a fully automated, next-generation sequencing (NGS) platform for turnkey diagnostics, including SARS-CoV-2 genomic characterization and detection of foodborne pathogens such as listeria and salmonella. It can also verify a food's ingredients, its GMO status, or conduct other tests.
Clear Labs was co-founded by Sasan Amini and Mahni Ghorashi in 2014, who left their jobs at a genomics company to start Clear Labs. The company acquired $6.5 million in series A financing in September 2015. In December 2016, the company closed a $16 million Series B funding round. This was followed by another $21 million round in October 2018.
Clear Labs was granted an Emergency Use Authorization (EUA) from the US FDA in September 2020 for its SARS-CoV-2 descriptive diagnostic test. Clear Labs launched in January 2021 a groundbreaking solution for whole genome sequencing surveillance of SARS-CoV-2 and its mutations. Clear Labs announced in March 2021 that the company had reached a critical milestone of over 50% public health laboratory penetration with its whole genome sequencing SARS-CoV-2 product, including laboratories such as Nebraska, Nevada, New York, California and Kansas, among others. Clear Labs Raised a $60M Series C round led by Morgan Stanley and T. Rowe Price in May 2021.
Clear Labs has also received governmental and professional certification for its food safety next generation sequencing platform, including from the International AOAC in December 2019 and the National Poultry Improvement Plan in October 2021.
Notes
References
External links
Official Website
Biotechnology companies of the United States
Companies based in Menlo Park, California
DNA sequencing | Clear Labs | [
"Chemistry",
"Biology"
] | 365 | [
"Molecular biology techniques",
"DNA sequencing"
] |
51,717,770 | https://en.wikipedia.org/wiki/Derivative%20code | Derivative code or Chameleon code is source code which has been derived entirely from one or more other machine readable file formats. If recursive transcompiling is used in the development process, some code will survive all the way through the pipeline from beginning to end, and then back to the beginning again.
This code is, by definition, derivative code. The following procedure can be used to easily test if any source code is derivative code or not.
Delete the code in question
Build (or compile) the project
If the build process simply replaces the source code which has been deleted, it is (obviously) code which has been derived from something else and is therefore, by definition, derivative code.
If the build process fails, and a human needs to re-create the deleted code by hand, this is again, by definition, hand code.
The transcompilers and other tools which create derivative code, are usually themselves either in part, or entirely hand code.
References
Computer programming | Derivative code | [
"Technology",
"Engineering"
] | 204 | [
"Computer programming",
"Computer science stubs",
"Software engineering",
"Computer science",
"Computing stubs",
"Computers"
] |
51,718,327 | https://en.wikipedia.org/wiki/Cryptographic%20splitting | Cryptographic splitting, also known as cryptographic bit splitting or cryptographic data splitting, is a technique for securing data over a computer network. The technique involves encrypting data, splitting the encrypted data into smaller data units, distributing those smaller units to different storage locations, and then further encrypting the data at its new location. With this process, the data is protected from security breaches, because even if an intruder is able to retrieve and decrypt one data unit, the information would be useless unless it can be combined with decrypted data units from the other locations.
History
The technology was filed for patent consideration in June 2003, and the patent was granted in June 2008.
Technology
Cryptographic splitting utilizes a combination of different algorithms to provide the data protection. A block of data is first encrypted using the AES-256 government encryption standard. The encrypted bits are then split into different shares and then each share is hashed using the National Security Agency's SHA-256 algorithm.
Applications
One application of cryptographic splitting is to provide security for cloud computing. The encrypted data subsets can be stored on different clouds, with the information required to restore the data being held on a private cloud for additional security. Security vendor Security First Corp uses this technology for its Secure Parser Extended (SPx) product line.
In 2009, technology services company Unisys gave a presentation about using cryptographic splitting with storage area networks. By splitting the data into different parts of the storage area network, this technique provided data redundancy in addition to security.
Computer giant IBM has written about using the technology as part of its Cloud Data Encryption Services (ICDES).
The technology has also been written about in the context of more effectively using sensitive corporate information, by entrusting different individuals within a company (trustees) with different parts of the information.
See also
Secret sharing
References
Information governance
Data security | Cryptographic splitting | [
"Engineering"
] | 398 | [
"Cybersecurity engineering",
"Data security"
] |
51,718,353 | https://en.wikipedia.org/wiki/Bisset%20Hawkins%20Medal | The Bisset Hawkins Medal is a triennial award made by the Royal College of Physicians of London to acknowledge work done in the preceding ten years in advancing sanitary science or promoting public health. It is named after Francis Bisset Hawkins (1796–1884), a distinguished London physician and is presented after the Harveian Oration.
The medal, made of gold, was endowed by Captain Edward Wilmot Williams in 1896.
Medallists
Medallists have been:
1899:
1902: William Henry Power
1905: Patrick Manson
1908: Sir
1911: Clement Dukes
1914: Sir Ronald Ross for his researches on malaria
1917: Sir Arthur Newsholme
1920: Sir William Heaton Hamer
1923: Sir Thomas Morison Legge
1926: Sir Ambrose Thomas Stanton
1929: Sir Edward Mellanby
1932: Thomas Henry Craig Stevenson
1935: Sir George Newman
1938: Major Greenwood
1941: Sir Frederick Norton Kay Menzies
1944: Brigadier J. A. Sinton
1947: Christopher Howard Andrewes
1950: Sir William Wilson Jameson
1953: William Norman Pickles
1956: Graham Selby Wilson
1959: Percy Stocks
1962: Sir Richard Doll, for contributions to preventative medicine
1965: Sir George Edward Godber
1968:
1971: Sir Derrick Melville Dunlop
1974:
1977: Major
1980: Jeremy Noah Morris
1983: Abraham Manie Adelstein
1986: Geoffrey Arthur Rose
1989: Sir Donald Acheson
1992: Rosemary Rue
1995: Sir Kenneth Charles Calman
1998:
2001: Kay-Tee Khaw
2004: Michael Gideon Marmot
2007:
2010:
2013:
2016: Sir Ian Gilmore
2019: Dr Sarah R Anderson - for work to improve national TB Control
2022: Dr Deirdre Anne Buckley
See also
List of medicine awards
Prizes named after people
References
British science and technology awards
Medicine awards
Awards established in 1896 | Bisset Hawkins Medal | [
"Technology"
] | 357 | [
"Science and technology awards",
"Medicine awards"
] |
51,718,561 | https://en.wikipedia.org/wiki/Weakly%20chained%20diagonally%20dominant%20matrix | In mathematics, the weakly chained diagonally dominant matrices are a family of nonsingular matrices that include the strictly diagonally dominant matrices.
Definition
Preliminaries
We say row of a complex matrix is strictly diagonally dominant (SDD) if . We say is SDD if all of its rows are SDD. Weakly diagonally dominant (WDD) is defined with instead.
The directed graph associated with an complex matrix is given by the vertices and edges defined as follows: there exists an edge from if and only if .
Definition
A complex square matrix is said to be weakly chained diagonally dominant (WCDD) if
is WDD and
for each row that is not SDD, there exists a walk in the directed graph of ending at an SDD row .
Example
The matrix
is WCDD.
Properties
Nonsingularity
A WCDD matrix is nonsingular.
Proof:
Let be a WCDD matrix. Suppose there exists a nonzero in the null space of .
Without loss of generality, let be such that for all .
Since is WCDD, we may pick a walk ending at an SDD row .
Taking moduli on both sides of
and applying the triangle inequality yields
and hence row is not SDD.
Moreover, since is WDD, the above chain of inequalities holds with equality so that whenever .
Therefore, .
Repeating this argument with , , etc., we find that is not SDD, a contradiction.
Recalling that an irreducible matrix is one whose associated directed graph is strongly connected, a trivial corollary of the above is that an irreducibly diagonally dominant matrix (i.e., an irreducible WDD matrix with at least one SDD row) is nonsingular.
Relationship with nonsingular M-matrices
The following are equivalent:
is a nonsingular WDD M-matrix.
is a nonsingular WDD L-matrix;
is a WCDD L-matrix;
In fact, WCDD L-matrices were studied (by James H. Bramble and B. E. Hubbard) as early as 1964 in a journal article in which they appear under the alternate name of matrices of positive type.
Moreover, if is an WCDD L-matrix, we can bound its inverse as follows:
where
Note that is always zero and that the right-hand side of the bound above is whenever one or more of the constants is one.
Tighter bounds for the inverse of a WCDD L-matrix are known.
Applications
Due to their relationship with M-matrices (see above), WCDD matrices appear often in practical applications.
An example is given below.
Monotone numerical schemes
WCDD L-matrices arise naturally from monotone approximation schemes for partial differential equations.
For example, consider the one-dimensional Poisson problem
for
with Dirichlet boundary conditions .
Letting be a numerical grid (for some positive that divides unity), a monotone finite difference scheme for the Poisson problem takes the form of
where
and
Note that is a WCDD L-matrix.
References
Matrices | Weakly chained diagonally dominant matrix | [
"Mathematics"
] | 621 | [
"Matrices (mathematics)",
"Mathematical objects"
] |
51,718,642 | https://en.wikipedia.org/wiki/L-matrix | In mathematics, the class of L-matrices are those matrices whose off-diagonal entries are less than or equal to zero and whose diagonal entries are positive; that is, an L-matrix L satisfies
See also
Z-matrix—every L-matrix is a Z-matrix
Metzler matrix—the negation of any L-matrix is a Metzler matrix
References
Matrices | L-matrix | [
"Mathematics"
] | 78 | [
"Matrices (mathematics)",
"Mathematical objects",
"Matrix stubs"
] |
51,719,045 | https://en.wikipedia.org/wiki/Propylene%20chlorohydrin | Propylene chlorohydrin usually refers to the organic compound with the formula CH3CH(OH)CH2Cl. A related compound, an isomer, is CH3CH(Cl)CH2OH. Both isomers are colorless liquids that are soluble in organic solvents. They are classified as chlorohydrins. Both are generated on a large scale as intermediates in the production of propylene oxide.
The reaction of aqueous solution of chlorine with propene gives a 10:1 ratio of CH3CH(OH)CH2Cl and CH3CH(Cl)CH2OH. These compounds are treated with lime to give propylene oxide, which is useful in the production of plastics and other polymers.
References
Organochlorides
Commodity chemicals | Propylene chlorohydrin | [
"Chemistry"
] | 166 | [
"Commodity chemicals",
"Products of chemical industry"
] |
51,719,806 | https://en.wikipedia.org/wiki/Parallel%20redrawing | In geometric graph theory, and the theory of structural rigidity, a parallel redrawing of a graph drawing with straight edges in the Euclidean plane or higher-dimensional Euclidean space is another drawing of the same graph such that all edges of the second drawing are parallel to their corresponding edges in the first drawing. A parallel morph of a graph is a continuous family of drawings, all parallel redrawings of each other.
Parallel redrawings include translations, scaling, and other modifications of the drawing that change it more locally. For instance, for graphs drawn as the vertices or edges of a simple polyhedron, a parallel drawing can be obtained by translating the plane of one of the polyhedron's face, and adjusting the positions of the vertices and edges that border that face. A polyhedron is said to be tight if its only parallel redrawings are similarities (combinations of translation and scaling); among the Platonic solids, the cube and dodecahedron are not tight (because of the possibility of translating one face while keeping the others fixed), but the tetrahedron, octahedron, and icosahedron are tight.
In three dimensions, even for drawings where all edges are axis-parallel and the drawing forms the boundary of a polyhedron, there may exist parallel redrawings that cannot be connected by a parallel morph. For two-dimensional planar drawings, with parallel edges required to preserve their orientation, a morph always exists when the slope number is two, but it is NP-hard to determine the existence of a morph for three or more slopes.
Any parallel morph can be parameterized so that the each point moves with constant speed along a line. The graphs that remain planar throughout such a motion can be derived from pseudotriangulations.
In structural rigidity, the existence of (infinitesimal) parallel redrawings of a structural framework is dual to the existence of an infinitesimal motion, one that preserves its edge lengths but not their orientations. Thus, a framework has one kind of motion if it has the other kind, but detecting the existence of a parallel redrawing may be easier than detecting the existence of an infinitesimal motion.
References
Geometric graph theory
Graph drawing
Mathematics of rigidity | Parallel redrawing | [
"Physics",
"Mathematics"
] | 464 | [
"Mathematics of rigidity",
"Graph theory",
"Mathematical relations",
"Mechanics",
"Geometric graph theory"
] |
51,723,991 | https://en.wikipedia.org/wiki/NGC%20240 | NGC 240 is a lenticular or spiral galaxy located in the constellation Pisces. It was discovered on October 22, 1886 by Lewis Swift.
References
External links
0240
Pisces (constellation)
002653
Spiral galaxies | NGC 240 | [
"Astronomy"
] | 47 | [
"Pisces (constellation)",
"Constellations"
] |
51,724,045 | https://en.wikipedia.org/wiki/NGC%20241 | NGC 241 is an open cluster located in the constellation Tucana. It is located within the Small Magellanic Cloud. It was discovered on April 11, 1834, by John Herschel.
References
0241
Open clusters
Tucana
Small Magellanic Cloud | NGC 241 | [
"Astronomy"
] | 52 | [
"Tucana",
"Constellations"
] |
59,510,003 | https://en.wikipedia.org/wiki/NGC%20712 | NGC 712 is a lenticular galaxy located 230 million light-years away in the constellation Andromeda. It was discovered by astronomer John Herschel in October 1828 and is a member of Abell 262.
See also
List of NGC objects (1–1000)
References
External links
712
6988
Andromeda (constellation)
Astronomical objects discovered in 1828
Lenticular galaxies
Abell 262
1352
Discoveries by John Herschel | NGC 712 | [
"Astronomy"
] | 87 | [
"Andromeda (constellation)",
"Constellations"
] |
59,510,831 | https://en.wikipedia.org/wiki/NGC%20714 | NGC 714 is a lenticular galaxy located 190 million light-years away in the constellation Andromeda. The galaxy was discovered by astronomer Bindon Blood Stoney on October 28, 1850 and is a member of Abell 262.
See also
List of NGC objects (1–1000)
References
External links
714
7009
Andromeda (constellation)
Astronomical objects discovered in 1850
Lenticular galaxies
Abell 262
1358
Discoveries by Bindon Blood Stoney | NGC 714 | [
"Astronomy"
] | 93 | [
"Andromeda (constellation)",
"Constellations"
] |
59,511,062 | https://en.wikipedia.org/wiki/Aitken%20interpolation | Aitken interpolation is an algorithm used for polynomial interpolation that was derived by the mathematician Alexander Aitken. It is similar to Neville's algorithm.
See also Aitken's delta-squared process or Aitken extrapolation.
External links
Polynomials
Interpolation | Aitken interpolation | [
"Mathematics"
] | 62 | [
"Polynomials",
"Algebra"
] |
59,511,302 | https://en.wikipedia.org/wiki/NGC%20717 | NGC 717 is a lenticular galaxy located 210 million light-years away in the constellation Andromeda. The galaxy was discovered by astronomer Bindon Blood Stoney on October 28, 1850 and is a member of Abell 262.
See also
List of NGC objects (1–1000)
NGC 714
References
External links
717
7033
Andromeda (constellation)
Astronomical objects discovered in 1850
Lenticular galaxies
Abell 262
1363
Discoveries by Bindon Blood Stoney | NGC 717 | [
"Astronomy"
] | 96 | [
"Andromeda (constellation)",
"Constellations"
] |
59,512,190 | https://en.wikipedia.org/wiki/Permutation%20category | In mathematics, the permutation category is a category where
the objects are the natural numbers,
the morphisms from a natural number n to itself are the elements of the symmetric group and
there are no morphisms from m to n if .
It is equivalent as a category to the category of finite sets and bijections between them.
References
Category theory | Permutation category | [
"Mathematics"
] | 74 | [
"Functions and mappings",
"Mathematical structures",
"Category theory stubs",
"Mathematical objects",
"Fields of abstract algebra",
"Mathematical relations",
"Category theory"
] |
59,513,916 | https://en.wikipedia.org/wiki/NGC%207741 | NGC 7741 is a barred spiral galaxy located in the constellation Pegasus. It is located at a distance of circa 40 million light years from Earth, which, given its apparent dimensions, means that NGC 7741 is about 50,000 light years across. It was discovered by William Herschel on September 10, 1784.
NGC 7741 has a strong bar and two spiral arms. The spiral arms are patchy and diffuse and their inner part forms a pseudoring. There are numerous HII regions along the bar and the spiral arms, and a total number of 10 HII region complexes have been observed, with radius 6 arcseconds. They have ages between 5 and 9 million years. The star formation rate in the central region of NGC 7741 is 0.022 per year per square kpc. The total stellar mass of NGC 7741 is estimated to be .
NGC 7741 belongs to a small galaxy group known as the NGC 7741 group. Other members of the group are the galaxies UGC 12732, and UGC 12791.
Gallery
References
External links
NGC 7741 on SIMBAD
Barred spiral galaxies
Pegasus (constellation)
7741
12754
72237
Astronomical objects discovered in 1784
Discoveries by William Herschel | NGC 7741 | [
"Astronomy"
] | 248 | [
"Pegasus (constellation)",
"Constellations"
] |
59,515,025 | https://en.wikipedia.org/wiki/Metabolic%20Score%20for%20Insulin%20Resistance | The Metabolic Score for Insulin Resistance (METS-IR) is a metabolic index developed with the aim to quantify peripheral insulin sensitivity in humans; it was first described under the name METS-IR by Bello-Chavolla et al. in 2018. It was developed by the Metabolic Research Disease Unit at the Instituto Nacional de Ciencias Médicas Salvador Zubirán and validated against the euglycemic hyperinsulinemic clamp and the frequently-sampled intravenous glucose tolerance test in Mexican population. It is a non-insulin-based alternative to insulin-based methods to quantify peripheral insulin sensitivity and an alternative to SPINA Carb, the Homeostatic Model Assessment (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI). METS-IR is currently validated for its use to assess cardio-metabolic risk in Latino population.
Derivation and validation
METS-IR was generated using linear regression against the M-value adjusted by lean body mass obtained from the glucose clamp technique in Mexican subjects with and without type 2 diabetes mellitus. It is estimated using fasting laboratory values including glucose (in mg/dL), triglycerides (mg/dL) and high-density lipoprotein cholesterol (HDL-C, in mg/dL) along with body-mass index (BMI). The index can be estimated using the following formula:
The index holds a significant correlation with the M-value adjusted by lean mass (ρ = −0.622) obtained from the euglycemic hyperinsulinaemic clamp study adjusted for age and gender as well as minimal model estimates of glucose sensitivity. In an open population cohort study in Mexican population, METS-IR was shown to predict incident type 2 diabetes mellitus and a value of METS-IR >50.0 suggested up to three-fold higher risk of developing type 2 diabetes after an average of three years. In a nation-wide population-based study of Chinese subjects, METS-IR was also shown to identify subjects with metabolic syndrome independent of adiposity. METS-IR also predicts visceral fat content, subcutaneous adipose tissue, fasting insulin levels and ectopic fat accumulation in liver and pancreas.
Comparison to other indexes
METS-IR was compared against other non-insulin-based methods to approximate insulin sensitivity including the Triglyceride-Glucose index (TyG), the triglyceride to HDL-C ratio, and the TyG-BMI index, yielding a higher correlation and area under the receiving operating characteristic curve compared to these other measures. When assessing its utility for identifying metabolic syndrome in Chinese subjects, Yu et al. suggested that the TyG and TG/HDL-C indexes had superior performance in their population owing to ethnic-specific variations in body composition. Given the role of ethnicity in modifying the performance of insulin sensitivity fasting-based indexes, further evaluations in different populations are required to establish performance of non-insulin-based methods.
See also
Insulin resistance
Homeostatic model assessment
SPINA-GBeta
SPINA-GR
Disposition index
Quantitative insulin sensitivity check index
Diabetes mellitus
Diabetes management
References
External links
Calculator to estimate METS-IR, the TyG index and TG/HDL-C ratio
Diabetes
Endocrinology
Human homeostasis
Lipid metabolism | Metabolic Score for Insulin Resistance | [
"Chemistry",
"Biology"
] | 697 | [
"Lipid biochemistry",
"Human homeostasis",
"Homeostasis",
"Lipid metabolism",
"Metabolism"
] |
59,515,440 | https://en.wikipedia.org/wiki/Alan%20Vaughan-Richards | Alan Vaughan-Richards (1925–1989) was a British-Nigerian architect who was active in the post-colonial architecture industry of Nigeria. He engaged architects on the potential influence of African forms in architectural design through publication of the journal West Africa Builder and Architect.
Vaughan-Richards incorporated the works of Nigerian artists in many of his projects. Trained in modern architecture in England, he then studied cultural uses of architecture in Nigeria, and many of his commissions were hybrids of both influences.
Education
Vaughan-Richards was educated at London Polytechnic (now University of Westminster) where he obtained a diploma in architecture in 1950. He also enrolled for a newly created course on Tropical Architecture at Architectural Association, London in 1956.
Career
Vaughan-Richards began his career in the 1950s working with the Architect Development Board in Iraq and subsequently Architect Co-Partnership in London. The firm was engaged in the design of a newly reconstructed Bristol Hotel and housing for oil and gas companies in Lagos. In the course of the project, Vaughan-Richards was involved in preliminary design and as a site supervisor visited Nigeria during tours of the projects. When Architect Co-Partnership pulled out of Nigeria, Vaughan-Richards stayed in the country and became a Nigerian citizen. His house in Ikoyi close to the Lagos lagoon and which was influenced by forms in Hausa village and designed in a modern style was used as his office. Many of his commissions included private houses and a staff housing facility for University of Lagos. He gained recognition among his private clients with his designs of generous shared or public spaces and broad corridors in his commissions.
American novelist Elaine Neil Orr described Vaughan-Richards' architectural style, writing that he "consistently applied curvilinear geometries in his designs, sometimes as adornment but often as integral elements of walls and rooms. Modular designs were his staple, initially from blocks and roof sheeting, and then from timber framing".
Vaughan-Richards co-founded and edited the West African Builder and Architect to provide information about architecture in Africa and later co-wrote Building Lagos with Kunle Akinsemoyin, a book documenting the development of Lagos.
Vaughan-Richards merged with Felix Ibru's Roye Ibru and Co. He was supervisor of the Architecture department of the University of Lagos where his commissions included Jaja Hall, University of Lagos, University of Lagos master plan; modern designs with tropical and West African forms such as Olaoluwakitan House and Alan Vaughan-Richards house. Many of his works were neglected or poorly maintained.
In the 1980s, he was involved in writing an inventory of Brazilian houses in Lagos for use by a preservation movement.
In the 1950s, new construction projects designed from adopted modern European architectural forms with consideration for Nigerian climate and which was led by Maxwell Fry and London trained Nigerian architects began to emerge as the dominant style in Lagos. Vaughan-Richards was among the modernist architect, but he wanted more exploration with the adoption of existing African forms, African art and use of materials such as timber. He was an advocate of incorporating African cultural forms and lifestyles in modern Nigerian architecture, a departure of the orthodox styles emerging in the 1950s that largely incorporated adaptation to the climatic conditions in Africa. His personal house built in the 1960s was an experimentation of traditional West African architectural forms with modern architecture principles such as the use of curvi-linear and circular geometries. Other projects such as the Ola-oluwakitan House stood out for the consideration given to African forms and originality, and later served as a model for other private houses.
Personal life
He married Ayo Vaughan-Richards (née Vaughan), a nurse who was the daughter of a hotelier from the Vaughan family of Lagos. They had four children including the filmmaker Remi Vaughan-Richards.
Publications
"Le Nigeria" in Rives coloniales : architectures, de Saint-Louis à Douala. 1993. .
Editor. ''West African Builder and Architect. Journal. 1963 - 1967.
Co-author. Building Lagos. 1977. Pengrail Ltd
References
British emigrants to Nigeria
1925 births
1989 deaths
Alumni of the University of Westminster
Architects from Lagos
20th-century Nigerian architects
Architecture writers
Alan
20th-century English architects
Naturalized citizens of Nigeria
Alumni of the Architectural Association School of Architecture
Architects from London
Academic staff of the University of Lagos
20th-century African-American people | Alan Vaughan-Richards | [
"Engineering"
] | 873 | [
"Architecture writers",
"Architecture"
] |
59,515,462 | https://en.wikipedia.org/wiki/EA-3966 | EA-3966 is a carbamate nerve agent. It is synthesized by reacting 2-dimethylaminomethyl-3-dimethylcarbamoxypyridine with 10-bromodecyltrimethylammonium bromide.
See also
3152 CT
EA-3887
EA-3990
EA-4056
T-1123
TL-1238
Decamethonium
References
Carbamate nerve agents
Pyridines
Quaternary ammonium compounds
Acetylcholinesterase inhibitors
Bromides
Bisquaternary anticholinesterases
Aromatic carbamates | EA-3966 | [
"Chemistry"
] | 127 | [
"Bromides",
"Salts"
] |
62,161,313 | https://en.wikipedia.org/wiki/Blastoid%20%28embryoid%29 | A blastoid is an embryoid, a stem cell-based embryo model which, morphologically and transcriptionally resembles the early, pre-implantation, mammalian conceptus, called the blastocyst. The first blastoids were created by the Nicolas Rivron laboratory by combining mouse embryonic stem cells and mouse trophoblast stem cells. Upon in vitro development, blastoids generate analogs of the primitive endoderm cells, thus comprising analogs of the three founding cell types of the conceptus (epiblast, trophoblast and primitive endoderm), and recapitulate aspects of implantation on being introduced into the uterus of a compatible female. Mouse blastoids have not shown the capacity to support the development of a foetus and are thus generally not considered as an embryo but rather as a model. As compared to other stem cell-based embryo models (e.g., Gastruloids), blastoids model the preimplantation stage and the integrated development of the conceptus including the embryo proper and the two extraembryonic tissues (trophectoderm and primitive endoderm). The blastoid is a model system for the study of mammalian development and disease. It might be useful for the identification of therapeutic targets and preclinical modelling.
References
Stem cells
Tissue engineering
Animal developmental biology | Blastoid (embryoid) | [
"Chemistry",
"Engineering",
"Biology"
] | 281 | [
"Biological engineering",
"Cloning",
"Chemical engineering",
"Biotechnology stubs",
"Tissue engineering",
"Medical technology"
] |
62,161,418 | https://en.wikipedia.org/wiki/GUSTO%20%28telescope%29 | GUSTO (Galactic / Extragalactic ULDB Spectroscopic Terahertz Observatory) is a high-altitude balloon mission that carries an infrared telescope to measure fine-structure line emission from the interstellar medium. The mission was developed by NASA's Explorers Program, and was launched on 31 December 2023 from Antarctica.
Overview
GUSTO is expected to provide the first complete study of the life cycle of the interstellar medium, the gas and dust from which all stars and planets are formed. The mission is a Mission of Opportunity (MO) of NASA's Explorer's Program and is expected to cost about US$40 million. It follows from the experience gained from two precursor or "pathfinder" missions: the Stratospheric Terahertz Observatory (STO) launched on 15 January 2012, and STO-2 launched on 8 December 2016. The principal investigator is Christopher Walker at the University of Arizona in Tucson, Arizona.
The telescope was lifted by a superpressure balloon to the stratosphere at an altitude of above Antarctica, at the edge of space. It mapped portions of the Milky Way galaxy and the Large Magellanic Cloud in three specific regions of the far infrared (FIR) portion of the electromagnetic spectrum called the "terahertz lines of carbon, nitrogen and oxygen".
GUSTO was launched on 31 December 2023, 06:30 UTC, from McMurdo, Antarctica, and stayed airborne for 57 days, 7 hours, 38 minutes, before landing safely in Antarctica on 26 February 2024. GUSTO was controlled and monitored from several stations around the United States.
Objective
The objective of GUSTO is to provide the first complete spectroscopic study of all phases of the stellar life cycle, from the formation of molecular clouds (also called stellar nurseries), through star birth and evolution, to the formation of interstellar gas clouds and the re-initiation of the cycle. This would help determine the composition, energetics, and dynamics of the interstellar medium. It will do so by observing simultaneously in three specific far infrared (FIR) wavelengths. The researchers state that "this unique and novel combination of data will provide information needed to untangle the complexities of the interstellar medium".
Telescope and detectors
The gondola, avionics and solar panels were provided by the Johns Hopkins Applied Physics Laboratory. The University of Arizona in Tucson provided the telescope with an array of cryogenic terahertz radiation superconducting heterodyne detectors built in a collaborative effort with the Massachusetts Institute of Technology (MIT), Arizona State University, the Netherlands Institute for Space Research (SRON), Virginia Diodes (VDI), and Ball Aerospace. The detectors measure the terahertz lines of carbon, oxygen and nitrogen, at 158 μm, 63 μm, and 205 μm respectively.
The gondola and instruments carried by the balloon have an approximate mass of and measures about 6 m wide by 6 m height (20 ft × 20 ft). The telescope has a mirror, which directs light to a series of superconducting detectors contained inside a cryostat that will keep them at .
Balloon
Originally proposed for use on a ULDB (UltraLong Duration Balloon) Superpressure balloon, issues with qualification of the balloon resulted in use of an alternative 39 million cubic feet volume, zero pressure balloon. The balloon was provided by NASA's Balloon Program Office.
The flight was designed to make use of a weather phenomenon known as an anticyclone that occurs during the Antarctic summer. The wind vortex would take the balloon on a circular flight trajectory over Antarctica for 55 to 120 days. Recovery was uncertain for GUSTO; as the southern winter progresses, the polar vortex weakens and the balloon could have left Antarctica and drifted northward. Upon mission completion on 26 February 2024, GUSTO descended by parachute and landed safely on Antarctic soil.
References
Infrared telescopes
Astronomical imaging
Observational astronomy
Explorers Program
2023 in science | GUSTO (telescope) | [
"Astronomy"
] | 808 | [
"Observational astronomy",
"Astronomical sub-disciplines"
] |
62,162,151 | https://en.wikipedia.org/wiki/Lynda%20Soderholm | Lynda Soderholm is a physical chemist at the U.S. Department of Energy's (DOE) Argonne National Laboratory with a specialty in f-block elements. She is a senior scientist and the lead of the Actinide, Geochemistry & Separation Sciences Theme within Argonne's Chemical Sciences and Engineering Division. Her specific role is the Separation Science group leader within Heavy Element Chemistry and Separation Science (HESS), directing basic research focused on low-energy methods for isolating lanthanide and actinide elements from complex mixtures. She has made fundamental contributions to understanding f-block chemistry and characterizing f-block elements.
Soderholm became a Fellow of the American Association for the Advancement of Science (AAAS) in 2013, and is also an Argonne Distinguished Fellow.
Early life and education
Soderholm was awarded her PhD in 1982 by McMaster University under the direction of Prof John Greedan. Her dissertation focused on characterizing the structural and magnetic properties of a series of ternary f-ion oxides. After graduating, she was awarded a NATO postdoctoral fellow at the Centre national de la recherche scientifique in France from 1982 until 1985. After a short postdoctoral appointment as an Argonne postdoctoral fellow she was promoted to staff scientist the same year. Over several years, she moved up the ranks, becoming a senior chemist in 2001. She was also an adjunct professor at the University of Notre Dame from 2003 until 2007. In 2021, Soderholm was appointed interim Division Director for the Chemical Sciences and Engineering Division.
Career and research
Uncovering structure of Yttrium-123 Superconductor
Early in her career, Soderholm focused on the characterizing the magnetic and electronic behavior of compounds containing f-ions (lanthanides and actinides) with a focus on high-Tc materials, compounds that are superconducting under usually high temperatures. She was part of the research group that first determined the structure of YBa2Cu3O7. Their discovery formed the foundation for the further developments in the broad field of superconductivity.
Understanding f-ion speciation in solution
Continuing her interest in the f-elements, Soderholm shifted her focus from solid-state materials to nanoparticles and solutions, taking advantage of advances in X-ray structural probes made available by synchrotron facilities. Building on her earlier work using neutron scattering, her team became the first to discover that plutonium exists in solution as tiny, well-defined nanoparticles. This work solved a longstanding problem in understanding transport of plutonium in the environment and resulted in the development of a new, patented approach to separating plutonium during nuclear reprocessing.
Using machine learning to evaluate molecular structures
Soderholm's more recent projects use machine learning to understand the influence of complex molecular structuring in solutions, in connection with low-energy processes for separation of f-block elements from complex mixtures.
Awards and honors
University of Chicago Board of Governors' Distinguished Performance Award, 2009.
Fellow of the American Association for the Advancement of Science, 2013.
Argonne Distinguished Fellow, 2016
DOE materials sciences research competition for Outstanding Scientific Accomplishments in Solid State Physics, 1987.
Select publications
Beno, M. A.; Soderholm, L.; Capone, D. W., II; Hinks, D. G.; Jorgensen, J. D.; Grace, J. D.; Schuller, I. K.; Segre, C. U.; Zhang, K., Structure of the single-phase high-temperature superconductor yttrium barium copper oxide (YBa2Cu3O7−δ). Appl. Phys. Lett. 1987, 51 (1), 57–9.
Soderholm, L.; Zhang, K.; Hinks, D. G.; Beno, M. A.; Jorgensen, J. D.; Segre, C. U.; Schuller, I. K., Incorporation of praseodymium in YBa2Cu3O7−δ: electronic effects on superconductivity. Nature (London) 1987, 328 (6131), 604–5.
Antonio, M. R.; Williams, C. W.; Soderholm, L., Berkelium redox speciation. Radiochim. Acta 2002, 90 (12), 851–856.
Soderholm, L.; Skanthakumar, S.; Neuefeind, J., Determination of actinide speciation in solution using high-energy X-ray scattering. Anal. Bioanal. Chem. 2005, 383 (1), 48–55.
Forbes, T. Z.; Burns, P. C.; Skanthakumar, S.; Soderholm, L., Synthesis, structure, and magnetism of Np2O5. J. Am. Chem. Soc. 2007, 129 (10), 2760–2761.
Soderholm, L.; Almond, P. M.; Skanthakumar, S.; Wilson, R. E.; Burns, P. C., The structure of the plutonium oxide nanocluster [Pu38O56Cl54(H2O)8]14-. Angew. Chem., Int. Ed. 2008, 47 (2), 298–302.
Jensen, M. P.; Gorman-Lewis, D.; Aryal, B.; Paunesku, T.; Vogt, S.; Rickert, P. G.; Seifert, S.; Lai, B.; Woloschak, G. E.; Soderholm, L., An iron-dependent and transferrin-mediated cellular uptake pathway for plutonium. Nat. Chem. Biol. 2011, 7 (8), 560–565.
Wilson, R. E.; Skanthakumar, S.; Soderholm, L., Separation of Plutonium Oxide Nanoparticles and Colloids. Angew. Chem., Int. Ed. 2011, 50 (47), 11234–11237.
Knope, K. E.; Soderholm, L., Solution and solid-state structural chemistry of actinide hydrates and their hydrolysis and condensation products. Chem. Rev. 2013, 113 (2), 944–994.
Luo, G.; Bu, W.; Mihaylov, M.; Kuzmenko, I.; Schlossman, M. L.; Soderholm, L., X-ray reflectivity reveals a nonmonotonic ion-density profile perpendicular to the surface of ErCl3 aqueous solutions. J. Phys. Chem. C 2013, 117 (37), 19082–19090.
Jin, G. B.; Lin, J.; Estes, S. L.; Skanthakumar, S.; Soderholm, L., Influence of countercation hydration enthalpies on the formation of molecular complexes: A thorium-nitrate example. J. Am. Chem. Soc. 2017, 139 (49), 18003–18008.
Patents
Solvent extraction system for plutonium colloids and other oxide nano-particles, (2016).
References
External links
Physical chemists
Year of birth missing (living people)
Living people
Argonne National Laboratory people
Women physical chemists
American chemists
Machine learning
Superconductors
McMaster University alumni
American Association for the Advancement of Science
21st-century women scientists
21st-century American chemists | Lynda Soderholm | [
"Chemistry",
"Materials_science",
"Engineering"
] | 1,623 | [
"Physical chemists",
"Machine learning",
"Superconductivity",
"Women physical chemists",
"Superconductors",
"Artificial intelligence engineering"
] |
62,162,863 | https://en.wikipedia.org/wiki/Serpentine%20Art%20and%20Nature%20Commons | The Serpentine Art and Nature Commons ("SANC" or "Serpentine Commons") is a not-for-profit organization founded in 1978. SANC is dedicated to preserving and maintaining the woodlands and serpentine ridge on the east shore of Staten Island and more specifically within the neighborhoods of Grymes Hill and Silver Lake.
The Serpentine Commons is a community-based group that provides open space, hikes and other educational opportunities to the North Shore of Staten Island on the more than 10 acres of the approximately 40 acres of land in the Serpentine Ridge Nature Preserve of the Special Hillsides Preservation District.
SANC owns the four lots comprising the over 10 acres of land thanks to a grant by the Trust for Public Land.
The steep slope park is open to everyone without charge. The hiking trails start at the bottom of the hill at 599 Van Duzer Street. There is also an entrance from the top of the hill at 255 Howard Avenue as well as a gated entrance by 30 Howard Circle.
The members meet monthly on the second Monday of the month at 7.30pm in the Kairos House at Wagner College. Anyone is invited to participate.
References
North Shore, Staten Island
Wildlife conservation
Grymes Hill, Staten Island | Serpentine Art and Nature Commons | [
"Biology"
] | 251 | [
"Wildlife conservation",
"Biodiversity"
] |
62,164,265 | https://en.wikipedia.org/wiki/Velma%20%28mudflat%29 | Velma (plural velme) is a Venetian dialect term derived from "melma" (mud). It is also used by Italian scientists to refer to lagunar mudflats (also called tidal flats), such as those found in the Lagoon of Venice. They are areas of shallow lagunar bottoms which are normally submerged, but emerge at low tides. They are generally without vegetation. Only associations of Zostera noltii (dwarf eelgrass) can be found. They originate from sediments carried by sea and stronger currents which are deposited on the lagoon bottom. They often surround the edges of the lagoon's barene (a venetian term for saltmarshes).
The velme, together with the barene (saltmarshes) and the shallow bottoms, constitute one of the most characteristic but also most fragile environments of the ecosystem of the Lagoon of Venice. They are subject to variations in their extent depending on the amount of materials (silt, sand and other sediments) they lose or acquire. Sediment acquisition leads to the consolidation of the velma's sediment soil and sediment loss leads to erosion of this soil. If the balance between consolidation and erosion fails, the velme and saltmarshes risk disappearing.
Erosion and loss of velma areas
The loss of velma areas in the Lagoon of Venice has been occurring for more than two centuries. From the early 19th century the combined saltmarsh area had decreased form 155 km2 to 40 km2. This has also involved a loss of velma areas because many of them surround the saltmarshes.
Velma areas are often under bathymetric (depth) pressure, which makes them less likely to emerge at low tides, leading to loss of stability and potential loss of their ecological function. This has been caused by infrastructural works carried out in the last two centuries. In the 19th century breakwaters were built at the lagoon inlets to stabilise their shape and orientation and to intensify the inflow of sea current in order to create conditions for deepening them and the channels which start from them. This was done to facilitate the transit of larger ships into the lagoon. In the 20th century, an even deeper and wider navigation canal was dug from the Malamocco inlet to the port of Marghera for large container ships and oil tankers to sail to new industrial areas. The depth of the channel form the Lido inlet was also increased to let large modern cruise ships through. These kinds of interventions have led to the displacement of sediments which are lost out of the lagoon and an increase in depth of the lagoon floor form and average of -0.75 m to one of -1.5 m since 1902.
The average loss of sediments is 2.2 million m3 per year. Erosion in the Lido basin was 14 cm in 1930-1970 and 12 cm in 1970–2000; in the Malamocco basin it was 20 cm and 33 cm respectively; in the Chioggia basin it was 8 cm and 20 cm; in the mid lagoon 14 cm and 20 cm.
The average deepening of lagoon floor has also made the wave action created by winds stronger, producing a further erosive effect. In addition to normal strength winds, Venice can also be hit by strong winds
caused the Bora from the northeast, especially in the winter, or the Scirocco from the southeast, which can occur from March to November. The latter, when combined a rising tide, can cause the acqua alta phenomenon (exceptionally high tides which cause flooding). Another erosive problem is caused by wave action created by passing motorboats.
Shelter for benthic species
The velme are ecologically important because strong variations in salinity and oxygenation created by submersion and emersion turn them into an environment which is even more selective than that of the saltmarshes. As a result, they form Benthic zones. Their substratum gives shelter to Benthos (lagoon bottom species): polychaetes (bristle worms), Daphnia (water fleas), molluscs (particularly bivalves) and some small crustaceans, such as caridean shrimps, from the low tide. These, in turn, provide food for some species of water birds, both nesting and migratory.
Food source for birds
Waders (called shorebirds in North America) are associated with the tidal variations in water level. They are found in mudflats which are exposed at low tide and or just about underwater in very shallow waters, where they search for their Benthos preys in the mud. Their thin, pointed beaks penetrate the mud to catch preys which do not have significant reactions. Their short legs allow them to walk where the water is only a few centimetres deep. Their legs and beaks are often brightly coloured, but their prey cannot see them and flee. During high tides, when their food is underwater, they rest at Roost sites. Some species feed throughout the tidal cycle shifting their feeding between mudflats and saltmarshes in synchrony with the tide rises and falls. The loss of mudflats and saltmarshes and disturbance at feeding and roosting sites poses a considerable threat to these populations. Their dependence on the presence of mudflats is a problem as these are one of the most difficult lagunar areas to restore and maintain. Many species are strongly migratory. They nest in northern Europe and Asia and winter on the Atlantic and Mediterranean coasts. Decreased food availability forces migratory species to prolong their flight periods, which results in a decrease in reproductive success and increase mortality.
Common waders in the lagoon are the black-winged stilt (Himantopus himantopus), pied avocet (Recurvirostra avosetta), Eurasian curlew (Numenius arquata), black-tailed godwit (Limosa limosa), common redshank (Tringa totanus), spotted redshank (Tringa erythropus), common greenshank (Tringa nebularia) and Eurasian oystercatcher (Haematopus ostralegus). The common redshank's nesting colony in the lagoon the largest in the Mediterranean, with 2000 specimens.
Seagrass of the velma
Zostera noltii (dwarf seagrass) and especially its subspecies Nanozostera noltii, which is more common in the Lagoon of Venice, are found in velma areas. Like other seagrasses, they are important for stabilising, re-suspending and consolidating sediments. They provide a defence against erosion and reduce wave energy. They also protect the benthic species that live in the velme. An area where it has been planted in a raised artificial velma habitat at Punta vecia Sud had been colonised by 47 benthic taxa. The biomass is seven times higher than that of the areas nearby. Zostera is, however, sensitive to being smothered by shifting sediments and has a low capacity to recover when buried. This may be due to its relatively short leaves and its lack of vertical rhizomes.
In addition the mentioned roles, it plays an important part in the winter diet of the whooper and mute swan, the brent goose, wigeon and wildfowl.
Protection of the velme
In the Lagoon of Venice some velma areas have been undergoing marked degradation due to the inconsistent nature of the bottom sediments or erosion. Consequently, there is degradation of the benthic species in the bottom sediments of the lagoon with pronounced bathymetric (depth) pressure. Projects to recover and regenerate these areas have been undertaken with the creation of new velma structures by creating confined areas and pouring sedimentary materials which include sandy and loamy components into them, using in part or totally materials from the dredging of the lagoon inlets. In areas under bathymetric pressure the bottom of the lagoon was increased in height to make it shallower. Small vivification canals were dug to direct the flow of water, improve sea water turnover and activate the processes of stabilisation of the bottom through an increase of primary production. Since these structures reach their highest physical and environmental value when they are colonised by Nanozostera noltii, a seagrass typical of the intertidal flats, these were planted in the intervention areas.
In the twenty-five years up to 2016, 18 artificial velma habitats covering a total of 2 km2 were created. This, together with the creation 11 km2 of saltmarshes, involved the reuse of 20 million m3 of sediments from the dredging of channels and canals. The creation of more velma habitats was in progress and more were planned. There is also a wider programme of planting seagrasses which also involves the planting of Cymodocea nodosa (little Neptune grass). It is found mainly near the inlets or in places with medium to high hydrodynamics and where salinity is not variable. It likes sediments with a high sand content. As it is of tropical origin, it starts growing rapidly in late spring, assuming an emerald colour, and does not grow in the winter, assuming a brownish colour. It is planted by the inlets or in canals or channels not far from them at a depth on -1.5 m or in artificial velma habitats in conjunction with Nanozostera noltii.
References
External links
Adriatic Sea
Lagoon of Venice
Mudflats
Bays of the Adriatic Sea
Coastal geography
Venetian Lagoon
Bays of Italy
Geography of Venice
Landforms
Wetlands | Velma (mudflat) | [
"Environmental_science"
] | 1,961 | [
"Hydrology",
"Wetlands"
] |
62,164,565 | https://en.wikipedia.org/wiki/Culture%20plate | In microbiology, a culture plate is a low flat-bottomed laboratory container for growing a layer of organisms such as bacteria, molds, and cells on a thin layer of nutrient medium. The most common types are the petri dish and multiwell plates.
See also
Roux culture bottle
Inoculation loop
Test tube
References
Microbiology equipment | Culture plate | [
"Biology"
] | 71 | [
"Microbiology equipment"
] |
54,545,388 | https://en.wikipedia.org/wiki/Stratified%20reproduction | Stratified reproduction is a widely used social scientific concept, created by Shellee Colen, that describes imbalances in the ability of people of different races, ethnicities, nationalities, classes, and genders to reproduce and nurture their children. Researchers use the concept to describe the "power relations by which some categories of people are empowered to nurture and reproduce, while others are disempowered," as Rayna Rapp and Faye D. Ginsburg defined the term in 1995.
Concept
Globally, women are confined to different societal standards on reproduction. The ability to choose whether women want to become pregnant is not available to all women. Contraception and abortions can be illegal or difficult to obtain depending on location or socioeconomic status. Women's experience of child birth has varied from required minimum number of children a mother must birth and honors for overachieving the set minimums to a restricted the number of children per household. In a broader sense, stratified reproduction asserts that certain categories of people are encouraged and coerced to reproduced while others are systematically discouraged to do so. The capacity to control one's reproductive choices is unequally distributed among race, sexual orientation, gender, class and socioeconomic status. Stratified reproduction also extends beyond the aspect of reproduction to the extent of conception, contraception, prenatal medical care, childcare, and the mother's role in their child's life.
In 1984, Shellee Colen coined the term "stratified reproduction" when studying West Indian childcare workers in New York City, who typically worked for wealthier white families. Colen highlighted differences between white and West Indian mothers’ ability to choose how they each care for their children. The white mothers hire a nanny to carry out the routine tasks of childcare while the West Indian mothers forgo the ability to raise their children so that they can financially support them. Colen drew the conclusion that child birth and childcare is experienced, valued, and rewarded differently depending on a mother's socioeconomic status and availability of resources.
Studies using the concept
Since the emergence of the term stratified reproduction, researchers have applied its concepts to analyze the different effects of varying social factors on reproduction and childcare. Rayna Rapp and Faye D. Ginsburg pioneered the application of stratified reproduction to different societies to emphasize the variation to which women experienced reproduction and childcare. In Rapp and Ginsburg's book, Conceiving the New World Order: The Global politics of Reproduction, they discuss several societies that limited women's choice on reproduction and childcare due to socioeconomic factors. They touch on Shellee Colen's research on West Indian nannies in New York and how they are unable to participate in their own child's childcare, because they must immigrate to America to find work to support their family. They also include Gail Kligman's research on abortion bans in Romania under Ceausescu’s rule. State policy required the Romanian women to birth at least four children in hopes of increasing the population for a more efficient socialist country. They also discuss China’s limit on the maximum number of children per household, and low-income African American women’s struggle to obtain proper contraceptives and abortions. Rapp and Ginsburg concluded that “global and local socioeconomic relations that form the context for stratified reproduction, whereby ‘some categories of people are empowered to nurture and reproduce, while others are disempowered’”, and that cultural ideologies and state policies reinforce the stratified reproduction implanted by socioeconomic factors.
The scope of use of the stratified reproduction framework is not limited to women’s access to contraceptives or lack thereof. Researchers are applying stratified reproduction to the health of the mothers and children. Infertility has also been linked to the effects of stratified reproduction. Scarce financial resources deters mothers from being able to reach effective medical services to help prevent infertility.
Infertility options and stratification
Medical infertility treatments
Infertility is just one aspect of stratified reproduction. Although it is estimated that 186 million people worldwide are affected by infertility, technology can be able to assist those who are infertile. In-Vitro-Fertilization (IVF) is one assisted reproductive technique (ART) that is used. IVF was developed over 30 years ago to help women with blocked or damaged fallopian tubes. IVF has helped many couples achieve their dreams of having a child. However, IVF is extremely expensive and/or inaccessible to many globally. In Central and Southern Africa "two-thirds of infertile women have diagnoses of tubal blockage attributable to sterilizing RTIs [Reproductive Tract Infections]" which is exactly what IVF was developed for. The high costs and inaccessibility keep infertility as a major aspect of stratified reproduction. According to a study done by Marcia C. Inhorn and Pasquale Patrizio, regions such as South Asia, sub-Saharan Africa, the Middle East and North Africa, Central and Eastern Europe and Central Asia have high infertility rates. While infertility is a global phenomenon, other issues within those regions play a role in their high infertility rates.
Secondary infertility, being unable to conceive after a previous pregnancy, is the most common form of infertility in women. Typically secondary infertility comes from RTIs. In countries where abortions are illegal, women will choose to have unsafe abortions. These unsafe abortions can lead to RTIs and secondary infertility if left untreated. Studies show that in places where laws are lifting the ban on abortions, secondary infertility rates are decreasing.
Racial disparities and socioeconomic status also play a role in infertility as well as the reported use of medical services for infertility. Data from the National Survey of Fertility Growth (NSFG) showed that infertility rates for black (19.8 percent) and Hispanic women (18.2) were much higher than those rates for white women (6.9 percent).The same study revealed that although women of color experience higher infertility rates, they reported having not received medical services for infertility at higher rates than their white counterparts. Socioeconomic status also provides barriers for women who do not have the flexibility to take off work and schedule appointments that higher socioeconomic status women do. Without public or even insurance company funding for these ARTs, this suggest that those in a higher socioeconomic standing should be able to reproduce, while those who cannot afford these treatments should not have the same ability to do so. This notion is furthered by policies such as the welfare reform act of 1996 which denies benefits to children who are born to mothers on welfare. However, race and class disparities in infertility treatment remain even in states that have mandated infertility insurance coverage suggesting that the issue of stratified infertility options go beyond political policies.
Adoption
Adoption is another infertility option that hosts many barriers to underrepresented populations. Cost is one factor that is a barrier for people with a low SES status. There is also a devaluation of children of color within the adoption system. The demand for white children is higher than that for children of color, thus leading some adoption agencies to charge more to adopt white children. This practice suggests that white children are of higher value than children of color.
Reproductive technologies and stratification
As there is a continual expansion of reproductive technologies, there is also increasing deficits in the access and utilization of these technologies due to stratified reproduction. Barriers achieving equal access to these reproductive technologies include high costs, lack of adequate healthcare or no healthcare, restrictive policies, lack of transportation and the lack of autonomy given to women to make their own reproductive decisions.
"Stratified Contraception"
Sheoran uses Shellee Colen's 'stratified reproduction' conceptual framing to propose that contraception is experienced hierarchically in places like India. Sheoran, when writing of Emergency Contraceptive Pills in India writes, 'ECPs in India thus make visible the reality of ‘stratified contraception,’ even as these technologies make inviting claims of eradicating stratification by providing all women with access to these pills at the local pharmacy'(pg. 250).
Sterilization
Sterilization is a relatively permanent form of contraception that can be used to give women reproductive control; however, this form of contraception has a history of blatant misuse. Sterilization was used to reinforce the social hierarchy where wealthy, white families were genetically superior to other groups of people. In this hierarchy, people of color, people with mental illnesses, criminals, those on welfare, single mothers and addicts were all seen as genetically inferiors; therefore justifying forced sterilization for the common good. The main target of forced sterilization were poor women of color.
In more recent history, there is still subtle and covert forms of coercion for certain groups to undergo sterilization. Sterilization rates still remain unequal between poor women of color and their white counterparts with Black and Native American women being twice as likely to have received a tubal sterilization. This data is found to be surprising taking into consideration that women of color are less likely to receive reproductive care or have health insurance to cover the costs of this procedure. A few explanations of this discrepancy is negative stereotypes of women of color as poor mothers and assuming women of color cannot afford children without being on welfare. These assumptions often lead to coercion and more invasive surgeries for reproductive issues that lead to sterilization. With women of color still at the forefront of this misuse of sterilization, the prison system has become a large target for coerced sterilizations. It was discovered that over 150 women were forcibly sterilized in prison between 2006 and 2010 because these women were deemed likely to return to prison. Even though sterilization was a costly procedure, physicians claimed that it would be better to pay for the procedure than pay for the welfare of these women's children.
Racial implications
Ethnicity and race also play a role in stratified reproduction. Western media often focuses on the infertility of middle-class white women, to the detriment of poor and nonwhite women. Race and ethnicity are common tools used to justify reproductive injustices and health disparities seen throughout the United States.
Latino populations and stratified reproduction
Recent scholarship has investigated the history of conflict around Latinas and fertility in the United States. These stories provided evidence that the United States had funded forced sterilization of Latino people and other ethnic groups. In their article, Elena R. Gutiérrez and Liza Fuentes study two communities, Puerto Rican women in Puerto Rico and New York and Mexican-origin women in Los Angeles. Once Puerto Rico became an American colony in 1898, people began to talk about Puerto Rico being overpopulated. By 1965, over 34% of mothers aged 20–49 had been sterilized. Not all women chose to be sterilized. Many of these women were used for contraceptive testing without their knowledge. Mexican-origin women were another community that experienced forced sterilization. Some women were forced into nonconsensual sterilizations, including as they were giving birth. Scholar Leo Chavez argues that these sterilizations came from the idea that Latinos are over-populating the U.S.
In his article, Leo Chavez discusses Latino fertility in the United States. He writes that their presence promoted anti-immigration sentiment and advertising suggesting that they should leave the United States and that their fertility was not welcome in the country. Puerto Ricans, such as those discussed in the article by Gutiérrez and Fuentes, were a part of this larger Latino community that was being targeted. In Chavez's article, he collects data to discuss fertility rates among Latinas, showing that, though Latina women were more fertile than their non-Hispanic white counterparts, they had fewer lifetime sexual partners.
Black women experiencing stratified reproduction
Nearly one in four African-American women live below the poverty line, which greatly increases the risks associated with bearing children. Black women are two and a half times more likely to die during pregnancy, and their children are two times more likely to die as infants. Many attempt to view this issue as a biological issue of African-American women; however, black women residing in other countries have less reproductive complication than their American counterparts. Black women are less likely to be given medical advice, to be warned of possible medical complications, and to receive helpful prenatal therapies. This differential treatment from medical health professional leads to more birth complications, adverse birth outcomes and fetal death thus contributing to the system of stratified reproduction.
Residential segregation may indirectly harm health through harmful living environments and limited access to resources. Segregated communities often are characterized by more crime, greater pollution, higher population densities, more poverty, and fewer and lower-quality services, leading to infant mortality. This includes forms of environmental injustice, which incorporates the unfair plotting of landfill facilities and the deliberate targeting of minority and low-income communities as repositories for hazardous waste sites. Even though residential segregation affects various minority groups, in the United States there are stark health discrepancies between black woman and their white counterparts. Flint, Michigan is a predominately black area that exemplifies the harmful impact low environmental quality can have on healthy reproduction: The Flint water crisis decreased fertility rates by 12 percent and raised infant mortality by 58 percent among Flint residents.
Queer stratified reproduction
More recently, there has been a closer look into how the system of stratified reproduction impacts the LGBTQ+ community. Stratified reproduction within the reproductive field of medicine feeds into a political economy that does not include a right to health, but a right to purchase health care if one can afford it and is deemed worthy of these biomedicines. States such as Arizona and Mississippi have recently seen legislative attempts to allow health care services to deny care to LGBTQ people; these stratifications of access to care also deny LGBTQ people the same possibilities for family planning and formation.
References
Feminist theory
Sociological terminology
Cultural anthropology
Kinship and descent
Human reproduction | Stratified reproduction | [
"Biology"
] | 2,943 | [
"Behavior",
"Human behavior",
"Kinship and descent"
] |
54,546,092 | https://en.wikipedia.org/wiki/Cyclic%20alkyl%20amino%20carbenes | Cyclic(alkyl)(amino) carbenes (CAACs) are a class of stable singlet carbene ligands that feature one amino and one sp3 alkyl group adjacent to the carbene carbon atom. CAACs are a subset of N-heterocyclic carbenes (NHCs) in which the replacement of an amino group on the "classical" diaminocarbene with a saturated carbon atom results in a carbene ligand that is both a better σ-donor and π-acceptor than classical NHCs. The lone pair on the nitrogen atoms in classical NHCs allows for π-donation from both nitrogen atoms, while substitution of one nitrogen with a carbon atom results in weaker π-donation from only one nitrogen substituent, thus making CAACs stronger π-acceptors and more electrophilic than classical NHCs. Like NHCs, CAACs have tunable steric and electronic properties that make them versatile ligands in both transition metal and main group. CAACs have been heavily studied. CAACs form stable adducts with otherwise reactive or unstable molecules. In materials science, CAACs stabilize species that have promising photophysical properties for organic light emitting diodes (OLEDs) and have been shown to stabilize single molecule magnets (SMMs).
Classes and synthesis of CAACs
Traditional CAACs (CAAC-5)
Reported by Bertrand in 2005, the first CAAC was synthesized by modification of the precursor imine formed from the reaction of 2,6-diisopropylaniline with 2-methylpropanal. This imine was deprotonated by lithium diisopropylamide (LDA) and 1,2-epoxy-2-methylpropane was then added to produce a lithium alkoxide. Addition of triflic anhydride (TfOTf) closes the cyclic system, producing an aldiminium salt that was deprotonated with LDA to yield the first CAAC "Ca".
A common synthesis is the hydroiminiumation route developed by Bertrand in 2007. The precursor imine is first deprotonated by LDA, followed by addition of an alkene with a halogenated substituent to form the alkenyl imine. Heating with HCl cyclizes the alkenyl imine to yield the aldiminium salt. Most aldiminium salts have been isolated in yields over 80%. Deprotonation with a strong base such as LDA or potassium bis(trimethylsilyl)amide (KHMDS) generates the CAAC.
Chiral CAACs
When the R1 and R2 are inequivalent, a chiral CAAC results.
Expanded ring CAACs (CAAC-6)
6-membered CAACs have been synthesized by slight modification to the CAAC-5 procedure; the main change is manifested in increasing the chain length of the alkene used in step 2. Modification of the backbone from CAAC-5 to CAAC-6 increases both the σ-donating and π-accepting strength of the ligand. CAAC-6 was shown to be more effective in the α-arylation of ketones with aryl chlorides than the analogous CAAC-5. Compared to Ru-CAAC-5, Six-membered Ru-CAAC-6 complexes also showed higher initiation rates for olefin metathesis, but increased steric bulk limited their catalytic activity.
Classic diamino NHCs have been synthetically modified to produce more ambiphilic carbenes by expanding the size of the backbone. 6-, 7-, and 8-membered rings (NHC-6, NHC-7, and NHC-8, respectively) have been reported for diamino NHCs. As the size of the backbone ring increases, so does the nucleophilicity at the carbon center. The traditional 5-membered CAACs show similar nucleophilicity to the eight-membered NHC with calculated highest occupied molecular orbitals (HOMO) of 5.290 eV (CAAC-5) vs. 5.110 eV (NHC-8), decreasing the motivation to synthesize expanded ring CAACs. As a result, ring-expanded CAACs have not been widely explored.
Bicyclic CAACs (BICAACs)
Bicyclic(alkyl)(amino) carbenes (BICAACs) are CAACs containing a bicyclic backbone. The bicyclic system forces the substituents on the carbon to adopt a "fan-like" geometry closer to that of a diamino NHC. As a result, BICAACs show stronger σ-donating and π-accepting properties compared to monocyclic CAACs. To synthesize BICAACs, the starting imine contains a cyclic alkene. The synthesis then follows the hydroiminiumation route in which the cyclization by HCl results in a bicyclic aldiminium salt that is then deprotonated to form the free carbene.
Bidentate CAACs
In 2016, the versatility of CAACs was further expanded to include bidentate CAACs containing a secondary pendant donor atom. By starting from a linear rather than a branched imine starting material, a donor group R can be added at the sp3 carbon by first deprotonating the carbon to be substituted using tert-butyllithium, then adding the alkene by an SN2-type reaction (Scheme 5). Bidentate CAACs featuring alkene, ether, amine, imine, and phosphine donors have been reported. Bidentate CAAC-Au(I) complexes have been used for C-C oxidative addition of biphenylene. Bidentate CAAC-Cu(I) compelxes have shown promise as catalysts for hydroarylation and anti-Markovnikov hydrohydrazination reactions.
Properties of CAACs
Electronic properties
The C-O stretching frequencies of cis-[RhCl(CO)2(L)] and cis-[IrCl(CO)2(L)], where L = NHC or CAAC allows for the determination of overall donating ability of L analogous to the Tolman electronic parameter (TEP). CAACs show lower C-O stretching frequencies (2013–2036 cm−1) than their NHC counterparts (2039–2049 cm−1), indicating that they are stronger donors.
The π-accepting abilities of NHCs and CAACs can be compared using 31P NMR shifts of the L-PPh adduct. CAACs show an downfield-shifted 31P NMR signals (56.2-68.9 ppm) compared to classical NHCs (-61.2 to -10.2 ppm) for 5-membered heterocyclic carbenes. These signals indicate higher C-P bond character, and therefore better π-backbonding from the phosphinidene to the CAAC ligands. By correlation to the TEPs for these complexes, the stronger σ-donating abilities for CAACs can be extracted.
The experimental superiority of σ-donor/π-acceptor CAACs compared to diaminocarbene NHCs is supported by DFT calculations of the frontier molecular orbitals of CAACs and NHCs. The more nucleophilic (higher HOMO) and electrophilic (lower LUMO) character of CAACs manifests in contraction of the singlet-triplet gap ΔEST from 285.1 kJ/mol for the saturated H-substituted NHC to 193.5 kJ/mol for the analogous saturated H-substituted CAAC.
The electronic properties of CAACs are affected by ring size. 6-membered CAACs increases the N-C-C angle, decreasing hybridization and thereby increasing p character of the carbene center. This increased p character raises the HOMO, decreasing the ΔEST further.
Steric properties
CAACs also show distinctve steric profiles. It is easy to produce symmetric NHCs, in which the N substituents are the same on either side of the carbene center. This is not the case for CAACs, which are synthesized by adding the N and C substituents in two different steps, allowing for more facile tuning of each substituent. The substituents on the carbene center are asymmetric and have differing hybridization between the sp2 nitrogen and sp3 carbon atom. This quaternary carbon atom in the α-position allows for variable steric effects by changing the substituents at both N and C.
The presence of the steric bulk at the α-position to the carbene rather than beta (attached to N) results in more steric encumberment at the carbene center. This effect is evident in the higher percent buried volume (%VBur) of CAACs compared to diamino NHCs at a distance of 0 Å from the carbene. For carbenes bearing a diiopropylphenyl group at the N substituent(s), the %VBur for CAACs (79.0-83.1) is markedly higher than the classical NHC (70.3).
This effect can be used to stabilize highly reactive main group and transition metal compounds. Because excessive steric hindrance can be an issue for some reactivity, NHCs and CAACs bearing substituents with multiple spatial conformations (e.g. cyclohexyl) offer "flexible steric bulk" for catalysis. The asymmetry of CAACs amplifies this flexible steric bulk by allowing for flexibility on only one side of the ligand. This asymmetric ligand scaffold has been exploited in developing novel catalysts for asymmetric transformations and small molecule activation.
CAAC Stabilization of Reactive Compounds
A major benefit of CAACs compared to other carbene or phosphine ligands is in their ability to stabilize highly reactive complexes that could not otherwise be isolated. The strong σ-donor and π-acceptor properties, as well as the steric bulk offered by CAAC ligands has allowed for the stabilization of numerous low-valent complexes across the periodic table.
s-block elements
Adducts of CAACs with Group 1 and 2 elements have been reported and shown to enhance their catalytic and redox properties compared to the elements alone. Group 1 (alkali metal) and Group 2 (alkaline earth metal) elements are very electropositive and are often seen in the +1 or +2 oxidation state. The strong π-accepting character of CAACS allowed for the isolation of the first example of a neutral Be(0) complex, which could not be isolated by attempts with diamino NHCs. A stable low valent Mg(I) radical has been reported, supported by a CAAC ligand which localizes the unfavorable spin density.
d-block elements
Reflecting their steric bulk, CAAC's stabilize low-coordinate complexes. The 14e, Rh(I) species [RhCl(CO)(CAAC)] is one example. Other examples are [Pd(allyl)(CAAC)]+ and [Au(CAAC)(η2-toluene)]+. CAAC's form tricoordinate Co(0), Fe(0), and Mn(0) complexes. EPR evidence supports these paramagnetic complexes are stabilized by offloading spin density onto the carbene ligand.
p-block elements
CAAC ligands have also unlocked previously unachievable main group complexes of Groups 13-15.
Group 13 consists of electron deficient elements that tend to behave as Lewis acids. A variety of CAAC adducts of group 13 elements have been explored. More notably, however, is the isolation of neutral group 13 radicals of B, Al, and Ga by reduction of a CAAC-MCl2 complex. CAACS have also been shown to stabilize nucleophilic borylenes and their corresponding radical cations.
Group 14 is dominated by organic chemistry, but CAACs have brought light to the reactivity of the heavier congeners. CAACs have been shown to stabilize more reactive carbon radicals by electron delocalization across the CAAC ligand. For instance, CAAC-stabilized carboxyl radicals can be isolated and stored at room temperature under inert atmosphere. CAACs can also stabilize bonding between the heavier group 14 and group 15 elements; numerous examples of homonuclear Si-Si, Si=Si, P-P, P=P, As-As, and Sb-Sb. Two coordinate CAAC-stabilized Sb(I) and Bi(I) carbone analogues have also been isolated; this reactivity is distinctive given the propensity for Sb and Bi complexes to dimerize.
CAACs in Catalysis
Transition metal catalysis
CAAC-supported ruthenium ethenolysis catalysts to produce linear alpha olefins (LAOs) from biomass-derived compounds. This was the first reported instance of olefin metathesis using ethylene gas. These catalysts were extremely active, producing turnover numbers (TON) greater than 100,000 at 1-3 ppm catalyst loading.
Coinage metal CAAC complexes have been well studied. CAAC-Au(I) complexes have been shown to catalyze the production of allynes via cross coupling, hydroamination, hydroamoniumation, and methylamination reactions. CAAC-Cu(I) complexes have been employed in cross-coupling reactions, hydroarylation, and small molecule activation. CAAC-Cu(I)BH4 is an efficient catalyst for the reduction of carbon dioxide to formate with a turnover number of 1800, which is a great improvement from other first row transition metal catalysts with TONs typically below 500. CAAC-Cu(I) catalysts have also been used for biologically-relevant asymmetric catalysis such as asymmetric conjugate borylation (ACB). Inclusion of a chiral center on the CAAC ligand allows for the production of β-substituted α,β-unsaturated esters with moderate enantioselectivities (up to 55%).
Small molecule activation
The ambiphilic nature of CAACs gives them properties previously attributed to transition metals, such as the ability to undergo oxidative addition and reductive elimination. The small singlet-triplet gap inherent in CAACs allows for these ligands to activate small molecules and enthalpically strong bonds, including CO, H2, B-H in HBpin, Si-H, P-H, P4, C-H, and N-H in NH3. As a result, CAACs can be implemented as economical metal-free catalysts for a variety of transformations that traditionally needed the aid of transition metal catalysts. Given that many transition metals are scarce and expensive, activation of small molecules using CAACs has important implications for the development of sustainable processes.
Photochemistry
Copper and gold CAAC complexes exhibit photoluminescence, relevant to organic light emitting diodes (OLEDs). Two coordinate (linear) Cu-CAAC complexes have weaker intermolecular interactions than other OLED candidates, allowing them to reach quantum efficiencies over 99%. Modification of the steric bulk around the carbene center allows for optimization of the excited state lifetimes, where shorter lifetimes are preferred for highest OLED efficiency. CAAC-Cu(I) complexes are also thermally stable up to 270 °C and emit at ambient temperatures, making them good candidates for OLED devices.
Single molecule magnets
Single-molecule magnet (SMMs) are an emerging field with implications for data storage and quantum computing. The strong accepting character of CAACs allows for the stabilization of the high spin states characteristic to SMMs. Iron and chromium SMMs stabilized by CAACs have been reported. These complexes undergo slow magnetic relaxation, making them promising SMMs.
References
Heterocyclic compounds with 1 ring
Nitrogen heterocycles
Carbenes | Cyclic alkyl amino carbenes | [
"Chemistry"
] | 3,450 | [
"Organic compounds",
"Inorganic compounds",
"Carbenes"
] |
54,546,108 | https://en.wikipedia.org/wiki/Portal%20%28computer%29 | Portal R2E CCMC was a portable microcomputer designed and marketed by the Réalisation et Études électroniques department of the French firm R2E Micral, and officially appeared in September 1980 at the Sicob show in Paris. Osborne 1, the first commercially successful portable computer, was only released eight months later, on 3 April 1981.
The machine was designed with a focus on payroll and accounting. Several hundred Portal computers were sold between 1980 and 1983.
Extremely rare, no museum has a Portal, and only two are in private collections.
The company R2E Micral is also known to have designed "the earliest commercial, non-kit computer based on a microprocessor", the Micral N. One of these machines was sold for 62,000 euros to Paul G. Allen, the co-founder of Microsoft (with Bill Gates), by the auctioneer Rouillac on June 11, 2017, for Allen's Seattle museum, Living Computers: Museum + Labs.
Specifications
The Portal was based on an Intel 8085 processor, 8-bit, clocked at .
It was equipped with of main RAM, a keyboard with 58 alphanumeric keys and 11 numeric keys (in separate blocks), a LED 32-character one-line screen, a floppy disk (capacity - ), a thermal printer (speed - ), an asynchronous channel, a synchronous channel, and a 220-volt power supply.
It came with two operating systems: Prologue and Basic Assembly Language (BAL).
Designed for an operating temperature of to , it weighed and its dimensions were 454515cm.
See also
R2E Micral
References
Bibliography
François Gernelle, Portal designer
Sources
This article is derived partly from the page of old-computers.com and feb-patrimoine.com.
Portable computers
Products introduced in 1980
Computer-related introductions in 1980
French inventions
History of computing in France
Information technology in France
1980 establishments in France
1983 disestablishments in France | Portal (computer) | [
"Technology"
] | 415 | [
"History of computing",
"History of computing in France"
] |
54,547,057 | https://en.wikipedia.org/wiki/EPS%20Statistical%20and%20Nonlinear%20Physics%20Prize | The EPS Statistical and Nonlinear Physics Prize is a biannual award by the European Physical Society (EPS) given since 2017. Its aim is to recognize
outstanding research contributions in the area of statistical physics, nonlinear physics, complex systems, and complex networks.
Early Career Recipients
Senior Recipients
See also
List of physics awards
References
Awards of the European Physical Society
Statistical mechanics | EPS Statistical and Nonlinear Physics Prize | [
"Physics"
] | 72 | [
"Statistical mechanics"
] |
54,547,190 | https://en.wikipedia.org/wiki/Recording%20studio%20as%20an%20instrument | In music production, the recording studio is often treated as a musical instrument when it plays a significant role in the composition of music. Sometimes called "playing the studio", the approach is typically embodied by artists or producers who favor the creative use of studio technology in record production, as opposed to simply documenting live performances in studio. Techniques include the incorporation of non-musical sounds, overdubbing, tape edits, sound synthesis, audio signal processing, and combining segmented performances (takes) into a unified whole.
Composers have exploited the potential of multitrack recording from the time the technology was first introduced. Before the late 1940s, musical recordings were typically created with the idea of presenting a faithful rendition of a real-life performance. Following the advent of three-track tape recorders in the mid-1950s, recording spaces became more accustomed for in-studio composition. By the late 1960s, in-studio composition had become standard practice, and has remained as such into the 21st century.
Despite the widespread changes that have led to more compact recording set-ups, individual components such as digital audio workstations (DAW) are still colloquially referred to as "the studio".
Definitions
"Playing the studio" is equivalent to 'in-studio composition', meaning writing and production occur concurrently. Definitions of the specific criterion of a "musical instrument" vary, and it is unclear whether the "studio as instrument" concept extends to using multi-track recording simply to facilitate the basic music writing process. According to academic Adam Bell, some proposed definitions may be consistent with music produced in a recording studio, but not with music that relies heavily on digital audio workstations (DAW). Various music educators alluded to "using the studio as a musical instrument" in books published as early as the late 1960s.
Rock historian Doyle Greene defines "studio as compositional tool" as a process in which music is produced around studio constructions rather than the more traditional method of capturing a live performance as is. Techniques include the incorporation of non-musical sounds, overdubbing, tape edits, sound synthesis, audio signal processing, and combining segmented performances (takes) into a unified whole. Despite the widespread changes that have led to more compact recording set-ups, individual components such as DAWs are still referred to as "the studio".
Evolution of recording processes
Composers have exploited the potential of recording technology since it was first made available to them. Before the late 1940s, musical recordings were typically created with the idea of presenting a faithful rendition of a real-life performance. Writing in 1937, the American composer John Cage called for the development of "centers of experimental music" places where "the new materials, oscillators, turntables, generators, means for amplifying small sounds, film phonographs, etc." would allow composers to "work using twentieth-century means for making music."
In the early 1950s, electronic equipment was expensive to own, and for most people, was only accessible through large organizations or institutions. However, virtually every young composer was interested in the potential of tape-based recording. According to Brian Eno, "the move to tape was very important", because unlike gramophone records, tape was "malleable and mutable and cuttable and reversible in ways that discs aren't. It's very hard to do anything interesting with a disc". In the mid 1950s, popular recording conventions changed profoundly with the advent of three-track tape recorders, and by the early 1960s, it was common for producers, songwriters, and engineers to freely experiment with musical form, orchestration, unnatural reverb, and other sound effects. Some of the best known examples are Phil Spector's Wall of Sound and Joe Meek's use of homemade electronic sound effects for acts like the Tornados.
In-studio composition became standard practice by the late 1960s and early 1970s, and remained so into the 2010s. During the 1970s, the "studio as instrument" concept shifted from the studio's recording space to the studio's control room, where electronic instruments could be plugged directly into the mixing console. As of the 2010s, the "studio as instrument" idea remains ubiquitous in genres such as pop, hip-hop, and electronic music.
Notable artists and works
1940s–1950s
Pioneers from the 1940s include Bill Putnam, Les Paul, and Tom Dowd, who each contributed to the development of common recording practices like reverb, tape delay, and overdubbing. Putnam was one of the first to recognize echo and reverb as elements to enhance a recording, rather than as natural byproducts of the recording space. He engineered the Harmonicats' 1947 novelty song "Peg o' My Heart", which was a significant chart hit and became the first popular recording to use artificial reverb for artistic effect. Although Les Paul was not the first to use overdubs, he popularized the technique in the 1950s.
Around the same time, French composers Pierre Schaeffer and Pierre Henry were developing musique concrete, a method of composition in which pieces of tape are rearranged and spliced together, and thus originated sampling. Meanwhile, in England, Daphne Oram experimented heavily with electronic instruments during her tenure as a balancing engineer for the BBC, however, her tape experiments were mostly unheard at the time.
1950s–1960s
Meek, Leiber, Stoller, and Spector
The BBC Radiophonic Workshop was one of the first to use the recording studio as a creative tool, often overlooked as was producing music for TV (and the prominent people were women) Daphne Oram, and Delia Derbyshire, who were early innovators.
English producer Joe Meek around the same time exploited the use of recording studios as instruments, and one of the first producers to assert an individual identity as an artist. He began production work in 1955 at IBC Studios in London. One of Meek's signature techniques was to overload a signal with dynamic range compression, which was unorthodox at the time. He was antagonized by his employers for his "radical" techniques. Some of these methods, such as close-miking instruments, later became part of normal recording practice. Music journalist Mark Beaumont writes that Meek "realised the studio-as-instrument philosophy years before The Beatles or The Beach Boys".
Discussing Jerry Leiber and Mike Stoller, Adam Bell describes the songwriting duo's productions for the Coasters as "an excellent example of their pioneering practices in the emerging field of production", citing an account from Stoller in which he recalls "cutting esses off words, sticking the tape back together so you didn't notice. And sometimes if the first refrain on a take was good and the second one lousy, we'd tape another recording of the first one and stick it in place of the second one."
Phil Spector, sometimes regarded as Joe Meek's American counterpart, is also considered "important as the first star producer of popular music and its first 'auteur' ... Spector changed pop music from a performing art ... to an art which could sometimes exist only in the recording studio". His original production formula (dubbed the "Wall of Sound") called for large ensembles (including some instruments not generally used for ensemble playing, such as electric and acoustic guitars), with multiple instruments doubling and even tripling many of the parts to create a fuller, richer sound. It evolved from his mid-1950s work with Leiber and Stoller during the period in which they sought a fuller sound through excessive instrumentation. Spector's 1963 production of "Be My Baby", according to Rolling Stone magazine, was a "Rosetta stone for studio pioneers such as the Beatles and Brian Wilson".
Beatles and Beach Boys
The Beatles' producer George Martin and the Beach Boys' producer-songwriter Brian Wilson are generally credited with helping to popularize the idea of the studio as an instrument used for in-studio composition, and music producers after the mid 1960s increasingly drew from their work. Although Martin was nominally the Beatles' producer, from 1964 he ceded control to the band, allowing them to use the studio as a workshop for their ideas and later as a sound laboratory. Musicologist Olivier Julien writes that the Beatles' "gradual integration of arranging and recording into one and the same process" began as early as 1963, but developed in earnest during the sessions for Rubber Soul (1965) and Revolver (1966) and "ultimately blossomed" during the sessions for Sgt. Pepper's Lonely Hearts Club Band (1967). Wilson, who was mentored by Spector, was another early auteur of popular music. Authors Jim Cogan and William Clark credit him as the first rock producer to use the studio as a discrete instrument.
According to author David Howard, Martin's work on the Beatles' "Tomorrow Never Knows", from Revolver, and Spector's production of "River Deep – Mountain High" from the same year were the two recordings that ensured that the studio "was now its own instrument". Citing composer and producer Virgil Moorefield's book The Producer as Composer, author Jay Hodgson highlights Revolver as representing a "dramatic turning point" in recording history through its dedication to studio exploration over the "performability" of the songs, as this and subsequent Beatles albums reshaped listeners' preconceptions of a pop recording. According to Julien, the follow-up LP Sgt. Pepper represents the "epitome of the transformation of the recording studio into a compositional tool", marking the moment when "popular music entered the era of phonographic composition." Composer and musicologist Michael Hannan attributes the album's impact to Martin and his engineers, in response to the Beatles' demands, making increasingly creative use of studio equipment and originating new processes.
Like Revolver, "Good Vibrations", which Wilson produced for the Beach Boys in 1966, was a prime proponent in revolutionizing rock from live concert performances into studio productions that could only exist on record. For the first time, Wilson limited himself to recording short interchangeable fragments (or "modules") rather than a complete song. Through the method of tape splicing, each fragment could then be assembled into a linear sequence – as Wilson explored on subsequent recordings from this period – allowing any number of larger structures and divergent moods to be produced at a later time. Musicologist Charlie Gillett called "Good Vibrations" "one of the first records to flaunt studio production as a quality in its own right, rather than as a means of presenting a performance", while rock critic Gene Sculatti called it the "ultimate in-studio production trip", adding that its influence was apparent in songs such as "A Day in the Life" from Sgt. Pepper.
1970s–2010s
Adam Bell credits Brian Eno with popularizing the concept of the studio as instrument, particularly that it "did not require previous experience, and in some ways, a lack of know-how might even be advantageous to creativity", and that "such an approach was typified" by Kraftwerk, whose members proclaimed "we play the studio". He goes on to say:
Producer Conny Plank was cited as creating "a world in sound using the studio as an instrument" producing bands such as Can, Cluster, Neu!, Kraftwerk and Ultravox amongst many others, the studio was seen as an integral part of the music.
Jamaican producer Lee "Scratch" Perry was noted for his 70s reggae and dub productions, recorded at his Black Ark studio. David Toop commented that "at its heights, Perry's genius has transformed the recording studio" into "virtual space, an imaginary chamber over which presided the electronic wizard, evangelist, gossip columnist and Dr. Frankenstein that he became."
From the late 1970s onward, hip hop production has been strongly linked to the lineage and technique of earlier artists who used the studio as an instrument. Jazz critic Francis Davis identified early hip-hop DJs, including Afrika Bambaataa and Grandmaster Flash, as "grassroots successors to Phil Spector, Brian Wilson, and George Martin, the 1960s producers who pioneered the use of the recording studio as an instrument in its own right."
Beginning in the 1980s, musicians associated with the genres dream pop and shoegazing made innovative use of effects pedals and recording techniques to create ethereal, "dreamy" musical atmospheres. The English-Irish shoegazing band My Bloody Valentine, helmed by guitarist-producer Kevin Shields, are often celebrated for their studio albums Isn't Anything (1988) and Loveless (1991). Writing for The Sunday Times, Paul Lester said Shields is "widely accepted as shoegazing's genius", with "his astonishing wall of sound, use of the studio as instrument and dazzling reinvention of the guitar making him a sort of hydra-headed Spector-Hendrix-Eno figure".
Chuck Eddy writes that, as the CD era emerged in the late 1980s, pop-metal was the first musical style to exploit contemporary recording studio techniques for "an aesthetic advantage", citing Def Leppard's Hysteria (1987) as a pioneering example and Lita Ford's Stiletto (1990) as a similar case, as both albums feature incidental high tech "whooshes and wobbles and giggles and boinks". Similarly, Eddy cites Kix's Blow My Fuse (1988) as an album whose sonics embody a futuristic "digital disco" sound, with "dub-doctored Who synths" and a 'studiofied' production.
American psychedelic rock band The Flaming Lips earned comparisons by critics to Brian Wilson's work when discussing their albums Zaireeka (1997) and The Soft Bulletin (1999), which were the results of extensive studio experimentation. When asked what instrument does he play, frontman Wayne Coyne simply stated "the recording studio".
See also
Acousmatic music
Art pop
Click track
Columbia-Princeton Electronic Music Center
Electroacoustic music
Experimental pop
Groupe de Recherches Musicales
Lo-fi/DIY music
Plunderphonics
Post-punk
Psychedelic music
Recording consciousness
Recording practices of the Beatles
Soundbreaking documentary series
Xenochrony
Studio di fonologia musicale di Radio Milano
Studio for Electronic Music (WDR)
Notes
References
Bibliography
Further reading
Recording studio
Popular music
New media
20th century in music
21st century in music
Audio engineering | Recording studio as an instrument | [
"Technology",
"Engineering"
] | 2,948 | [
"Multimedia",
"Electrical engineering",
"New media",
"Audio engineering"
] |
54,547,199 | https://en.wikipedia.org/wiki/Ernest%20Hartmann | Ernest Hartmann (1934 – 7 August 2013) was an American psychoanalyst and sleep researcher. He is known for pioneering sleep and dream studies, incorporating neurophysiology, endocrinology, and biochemistry into his work.
Life and career
Hartmann was born on Feb 25, 1934, in Vienna, Austria. His father was Heinz Hartmann (1894–1970), a widely known psychoanalyst and one of the founders of ego psychology, and his mother was Dora (Karplus) Hartmann (1902-1974), a pediatrician, psychiatrist, and psychoanalyst. He had one brother, Lawrence, born in 1937. In 1938, the family left Vienna, due to the rise of Nazism, and went to Paris and then to Switzerland; they finally settled in New York City in 1941, where EH graduated from the Ethical Culture Fieldston School in 1951. EH went on to the University of Chicago, and then the Yale University School of Medicine, where he received his M.D. in 1958. After an internship at Einstein, he did his residency in psychiatry at Massachusetts Mental Health Center, and went on to do research on sleep at the National Institute of Mental Health.
Hartmann began his career as an assistant clinical professor of psychiatry at Tufts University School of Medicine in Boston from 1964 to 1966, then as an assistant professor of psychiatry from 1966 to 1969, before properly becoming a professor in 1975, one of only three full professors at the School of Medicine at that time. He held that position until he retired from Tufts in 2013.
Hartmann was the former president of the International Association for the Study of Dreams and the founding editor for their journal, Dreaming. He served as lieutenant commander in the US Public Health Service from 1962 to 1964 and held multiple high-level positions in tandem with his duties at Tufts, including but not limited to, directing the Sleep and Dream Laboratory in the Boston State Hospital from 1964 to 1980, the Sleep Laboratory at the West-Ros-Park Mental Health Centre, and the Sleep Disorders Center at the Newton-Wellesly Hospital.
During his career as a researcher of sleep and dreams for 55 years, he published more than 350 articles and 9 books while giving a myriad of presentations and talks across the world. In 1967, Hartmann published his first book called The Biology of Dreaming.
Hartmann was married twice, first to Barbara Snow Hengst, from 1961 to 1974, then to Eva Neumann, from 1995 to 1999; both of these marriages ended in divorce. He had two children with Barbara Snow Hengst; Jonathan Hartmann, born 1966, and Katherine Hartmann. born 1968
Hartmann lived in Newton Highlands, Massachusetts. He died in Truro, Massachusetts, on the 7th of August, 2013 as a result of heart failure, at the age of 79.
Selected works
The Functions of Sleep. New Haven, CT: Yale University Press. 1973.
Boundaries in the Mind: A New Psychology of Personality. New York: Basic Books, 1991.
The Nature and Functions of Dreaming. Oxford University Press, 2010.
Boundaries: A New Way to Look at the World. Summerland, CA: CIRCC EverPress, 2011.
References
Austrian emigrants to the United States
American psychoanalysts
Sleep researchers
1934 births
2013 deaths | Ernest Hartmann | [
"Biology"
] | 665 | [
"Sleep researchers",
"Behavior",
"Sleep"
] |
54,548,788 | https://en.wikipedia.org/wiki/NGC%207070A | NGC 7070A is a face-on lenticular galaxy located about 100 million light-years away in the constellation of Grus.
Physical characteristics
NGC 7070A has a companion, the spiral galaxy NGC 7070 which are separated from each other at a projected distance of about . It has dust lanes which cross it and incomplete shells surrounding it. Also, there are faint luminous tails extending from the galaxy towards NGC 7070. It is theorized that these features may have formed due to the accretion of a smaller disk galaxy about a billion years ago which got disrupted by NGC 7070A.
Nearby galaxies
NGC 7070A is member of a group of galaxies known as the NGC 7079 Group.
Active galactic nucleus
XMM-Newton observations of NGC 7070A show that the galaxy hosts moderate AGN activity.
See also
List of NGC objects (7001–7840)
Centaurus A
NGC 1316
References
External links
Lenticular galaxies
Active galaxies
Peculiar galaxies
Grus (constellation)
7070A
66909
NGC 7079 Group | NGC 7070A | [
"Astronomy"
] | 212 | [
"Grus (constellation)",
"Constellations"
] |
54,550,259 | https://en.wikipedia.org/wiki/Cyphal | Cyphal is a lightweight protocol designed for reliable intra-vehicle communications using various communications transports, originally destined for CAN bus, but targeting various network types in subsequent revisions. OpenCyphal is an open-source project that aims to provide MIT-licensed implementations of the Cyphal protocol. The project was known as UAVCAN (Uncomplicated Application-level Vehicular Computing and Networking) prior to rebranding in March 2022.
History
The first RFC broadly outlining the general ideas that would later form the core design principles of Cyphal (branded UAVCAN at the time) was published in early 2014. It was a response to the perceived lack of adequate technology that could facilitate robust real-time intra-vehicular data exchange between distributed components of modern intelligent vehicles (primarily unmanned aircraft).
Since the original RFC, the protocol has been through three major design iterations, which culminated in the release of the first long-term stable revision in 2020 (6 years later) labelled UAVCAN v1.0. In the meantime, the protocol has been deployed in numerous diverse systems including unmanned aerial vehicles, spacecraft, underwater robots, racing cars, general robotic systems, and micromobility vehicles. In 2022, the protocol was rebranded as Cyphal.
Cyphal is positioned by its developers as a highly deterministic, safety-oriented alternative to high-level publish-subscribe frameworks such as DDS or the computation graph of ROS, which is sufficiently compact and simple to be usable in deeply embedded high-integrity applications. Cyphal has been shown to be usable with bare metal microcontrollers equipped with as little as 32K ROM and 8K RAM.
The protocol is open and can be reused freely without approval or licensing fees. The development of the core standard and its reference implementations is conducted in an open manner, coordinated via the public discussion forum.
As of 2020, the project is supported by several major organizations including NXP Semiconductors and the Dronecode Project.
History of Cyphal in the context of other serial protocols
a. MODBUS often runs over RS-232.
b. DDS Borrows an Interface Definition Language from CORBA.
c. MODBUS over TCP port 502.
d. Airbus approaches ARINC to request a new CAN standard be developed. Michael Stock provides his experience developing CAN Aerospace. ARINC-825-1 is the result.
e. First AVB standard is published by the AVB Task Group of the IEEE 802.1 working group. IEEE1722-2011 is released.
f. The AVB Task Group is renamed the TSN Task Group.
g. ROS2 Builds on top of DDS. Typical media for distributed ROS2 systems is Ethernet.
h. 802.1Qbv and 802.1Qbu are released, enabling fully deterministic Ethernet networks to be defined.
i. Pavel Kirienko leads an open-source effort to define UAVCAN v0. Initially, it only supports CAN 2.0B.
j. Airbus gives a presentation to the IEEE, “Avionics Full Duplex Ethernet and the Time-Sensitive Networking Standard” which proposes incorporating AFDX into the TSN standards.
k. ARINC 825-4 adds support for CAN-FD and defines tunneling over ARINC-664.
l. Amazon Prime Air defines a minimal set of changes to v0 adding CAN-FD support. The unofficial variant is dubbed v0.5. At the same time, at the Stockholm Summit, UAVCAN v1 was conceived.
m. 10 BASE T1S is added to IEEE 802.3 defining half-duplex, two-wire, multi-drop Ethernet media with PLCA (PHY-Level Collision Avoidance). The specification is targeted at automotive and industrial use cases (e.g. MODBUS replacement).
n. Airbus A380 ends production.
o. UAVCAN v1 becomes beta.
p. DroneCAN takes over maintenance of the UAVCAN v0/v0.5 specification and advancement on top of it.
q. UAVCAN v1 is renamed Cyphal.
Design
Cyphal provides zero-cost abstractions that are approachable and familiar to software engineers without compromising on functional safety and determinism. As a new technology, it is unencumbered by legacy and borrows heavily from recent developments in the field of general information technology. The protocol offers a stateless publish-subscribe communication model where a node can begin operation immediately upon connection to the network to accommodate high-integrity applications.
The protocol has two clearly separated major components: the transport layer that works on top of reliable vehicular networks such as Ethernet or CAN FD, and the transport-agnostic presentation (serialization) layer based on the so-called Data Structure Description Language (DSDL). The protocol has been shown to be implementable in less than 1000 logical lines of code.
DSDL is ideologically similar to the interface description language used in ROS, except that it introduces additional static constraints in order to render the solution suitable for real-time high-integrity embedded systems. The similarity prompted some developers to interface ROS with Cyphal using automated translation layers.
Core principles
The protocol is built around the following core design principles that are intended to ensure that the solution is well-suited for modern complex safety-critical vehicular systems.
Democratic network — There is no master node. All nodes in the network have the same communication rights; there should be no single point of failure.
Facilitation of functional safety — Cyphal system designers have the necessary guarantees and tools at their disposal to analyze the system and ensure its correct behavior.
High-level communication abstractions — The protocol supports publish/subscribe and remote procedure call communication semantics with statically defined and statically verified data types (schema). The data types used for communication are defined in a clear and platform-agnostic way, that can be easily understood by both machines and humans.
Facilitation of cross-vendor interoperability — Cyphal provides a common foundation that different vendors can build upon to ensure that their equipment is interoperable. Cyphal provides a generic set of standard application-agnostic communication data types.
Well-defined generic high-level functions — Cyphal defines standard services and messages for common high-level functions, such as: network discovery, node configuration, node software update, node status monitoring, network-wide time synchronization, plug-and-play node support, etc.
Atomic data abstractions — Nodes are able to exchange large data structures that exceed the capacity of a single transport frame. Cyphal performs automatic data decomposition and reassembly at the protocol level, hiding the related complexity from the application.
High throughput, low latency, determinism — Cyphal adds very low overhead to the underlying transport protocol, which ensures high throughput and low latency. This makes Cyphal well-suited for hard real-time applications.
Support for redundant interfaces and redundant nodes — Cyphal is suitable for applications that require modular redundancy.
Simple logic, low computational requirements — Cyphal targets a wide variety of embedded systems, from high-performance on-board computers, to extremely resource-constrained microcontrollers. It is inexpensive to support in terms of computing power and engineering hours, and advanced features can be implemented incrementally as needed.
Rich data type and interface abstractions — An interface description language is a core part of the technology, allowing deeply embedded subsystems to interface with higher-level systems directly (and in a maintainable manner), while enabling simulation and functional testing.
Support for various transport protocols — Cyphal is usable with several different transports, and can be extended to support other transport protocols in the future.
API-agnostic standard — Unlike some other networking standards, Cyphal does not attempt to describe the application program interface (API). Any details that do not affect the behavior of an implementation observable by other participants of the network are outside of the scope of the specification.
Open specification and reference implementations — The Cyphal specification is, and will always be, open and free to use for everyone. The reference implementations are distributed under the terms of the permissive MIT License or released into the public domain.
Transport layer
Cyphal/CAN
The CAN transport is built on top of CAN and CAN FD using 29-bit identifiers. The CAN payload includes a fixed-size overhead of one byte per frame for the needs of the transport layer.
Cyphal/UDP
The Cyphal/UDP transport has been proposed for real-time Ethernet-based vehicular networks. The design is said to be influenced by AFDX, DDS/RTPS, and SOME/IP.
Standard data types
Like other similar technologies, Cyphal provides a library of common data types, managed and curated by the protocol maintainers, that are intended to address certain common issues in popular applications. These data types supplement vendor-specific or application-specific data types defined by adopters, much like a programming language would normally define a standard library to be relied upon by software developed by the user. The protocol specification provides a set of rules intended to avoid conflicts and enhance interoperability of data types defined by independent vendors.
References
External links
Public forum for development coordination and feedback
Standards
Network protocols
Serial buses
Computer buses
Computer networks engineering | Cyphal | [
"Technology",
"Engineering"
] | 1,946 | [
"Computer networks engineering",
"Computer engineering"
] |
54,550,458 | https://en.wikipedia.org/wiki/Trophic%20coherence | Trophic coherence is a property of directed graphs (or directed networks). It is based on the concept of trophic levels used mainly in ecology, but which can be defined for directed networks in general and provides a measure of hierarchical structure among nodes. Trophic coherence is the tendency of nodes to fall into well-defined trophic levels. It has been related to several structural and dynamical properties of directed networks, including the prevalence of cycles and network motifs, ecological stability, intervality, and spreading processes like epidemics and neuronal avalanches.
Definition
Consider a directed network defined by
the adjacency matrix .
Each node can be assigned a trophic level according to
where is 's in-degree, and nodes
with (basal nodes) have by convention.
Each edge has a trophic difference associated, defined as .
The trophic coherence of the network is a measure of how tightly peaked the distribution of trophic distances,
,
is around its mean value, which is always .
This can be captured by an incoherence parameter ,
equal to the standard deviation of :
where is the number of edges in the network.
The figure shows two networks which differ in their trophic coherence. The position of the nodes on the vertical axis corresponds to their trophic level. In the network on the left, nodes fall into distinct (integer) trophic levels, so the network is maximally coherent .
In the one on the right, many of the nodes have fractional trophic levels, and the network is more incoherent .
Trophic coherence in nature
The degree to which empirical networks are trophically coherent (or incoherent) can be investigated by comparison with a null model.
This is provided by the basal ensemble, which comprises networks in which all non-basal nodes have the same proportion of basal nodes
for in-neighbours. Expected values in this ensemble converge to those of the widely used configuration ensemble in the limit , (with and the numbers of nodes and edges),
and can be shown numerically to be a good approximation for finite random networks. The basal ensemble expectation for the incoherence parameter is
where is the number of edges connected to basal nodes.
The ratio measured in empirical networks reveals whether they are more or less coherent than the random expectation.
For instance, Johnson and Jones find in a set of networks that food webs are significantly coherent , metabolic networks are significantly incoherent , and gene regulatory networks are close to the random expectation .
Trophic levels and node function
There is as yet little understanding of the mechanisms which might lead to particular kinds of networks becoming significantly
coherent or incoherent. However, in systems which present correlations between trophic level and other features of nodes,
processes which tended to favour the creation of edges between nodes with particular characteristics could induce coherence or incoherence.
In the case of food webs, predators tend to specialise on consuming prey with certain biological properties (such as size, speed or behaviour)
which correlate with their diet, and hence with trophic level.
This has been suggested as the reason for food-web coherence. However, food-web models based on a niche axis do not reproduce realistic trophic coherence, which may mean either that this explanation is insufficient, or that several niche dimensions need to be considered.
The relation between trophic level and node function can be seen in networks other than food webs. The figure shows a word adjacency network derived from the book Green Eggs and Ham, by Dr. Seuss. The height of nodes represents their trophic levels (according here to the edge direction which is the opposite of that suggested by the arrows, which indicate the order in which words are concatenated in sentences). The syntactic function of words is also shown with node colour. There is a clear relationship between syntactic function and trophic level: the mean trophic level of common nouns (blue) is , whereas that of verbs (red) is .
This example illustrates how trophic coherence or incoherence might emerge from node function, and also that the trophic structure of networks provides a means of identifying node function in certain systems.
Generating trophically coherent networks
There are various ways of generating directed networks with specified trophic coherence, all based on gradually introducing new edges
to the system in such a way that the probability of each new candidate edge being accepted depends on the expected trophic difference it would have.
The preferential preying model is an evolving network model similar to the Barábasi-Albert model of preferential attachment, but inspired on an ecosystem that grows through immigration of new species.
One begins with basal nodes and proceeds to introduce new nodes up to a total of .
Each new node is assigned a first in-neighbour (a prey species in the food-web context) and a new
edge is placed from to . The new node is given a temporary trophic level .
Then a further new in-neighbours are chosen for from among those in the network according to their trophic levels. Specifically, for a new candidate in-neighbour , the probability of being chosen is a function of
. Johnson et al use
where is a parameter which tunes the trophic coherence: for maximally coherent networks are generated, and
increases monotonically with for .
The choice of is arbitrary. One possibility is to
set to ,
where is the number of nodes already in the network when arrives, and is a random variable drawn from a Beta distribution
with parameters and
( being the desired number of edges).
This way, the generalised cascade model is recovered in the limit , and the degree distributions are as in the niche model and generalised niche model.
This algorithm, as described above, generates networks with no cycles (except for self-cycles, if the new node is itself considered among its candidate in-neighbours ). In order for cycles of all lengths to be a possible, one can consider new candidate edges in which the new node is the in-neighbour as well as those in which it would be the out-neighbour. The probability of acceptance of these edges,
, then depends on .
The generalised preferential preying model is similar to the one described above, but has certain advantages. In particular, it is more analytically tractable, and one can generate networks with a precise number of edges .
The network begins with basal nodes, and then a further new nodes are added in the following way. When each enters the system, it is assigned a single in-neighbour randomly from among those already there. Every node then has an integer temporary trophic level
. The remaining edges are introduced as follows. Each pair of nodes has two temporary trophic distances associated, and . Each of these candidate edges is accepted with a probability that depends on this temporary distance. Klaise and Johnson use
because they find the distribution of trophic distances in several kinds of networks to be approximately normal, and this choice leads to a range of the parameter in which . Once all the edges have been introduced, one must recalculate the trophic levels of all nodes, since these will differ from the temporary ones originally assigned unless .
As with the preferential preying model, the average incoherence parameter of the resulting networks is a monotonically increasing function of for . The figure above shows two networks with different trophic coherence generated with this algorithm.
References
External links
Why don't large ecosystems just collapse?
Looplessness
Trophic Coherence Could Help Solve the Mystery of Coexistence within Complex Ecosystems
Trophic coherence explains why networks have few feedback loops and high stability
Samuel Johnson's website
Nick Jones's website
Ecology
Directed graphs
Graph theory | Trophic coherence | [
"Mathematics",
"Biology"
] | 1,610 | [
"Discrete mathematics",
"Ecology",
"Graph theory",
"Combinatorics",
"Mathematical relations"
] |
54,550,463 | https://en.wikipedia.org/wiki/William%20Kolakoski | William George Kolakoski (September 17, 1944 – July 26, 1997), known as Bill to family and friends, was an American artist and recreational mathematician who is most famous for devising and giving his name to the Kolakoski sequence, a self-generating sequence of integers that has been extensively studied by mathematicians since he first described it in the American Mathematical Monthly in 1965.
Life and education
Kolakoski was born September 17, 1944, in Pittsburgh, Pennsylvania, the son of George Leon Kolakoski and his wife Eleanor (née Gale). He had many interests as a boy, including art, philosophy and mathematics, but chose to study fine art at the Carnegie Institute of Technology (CIT) (now Carnegie Mellon University) because he felt that, while he could study mathematics and philosophy independently, he needed the support of others to make a career in art. His fellow students were struck by his sharp intelligence, breadth of knowledge and skills in many different fields, including the ability to play good chess without making a particular study of the game.
He graduated from CIT with honors as a Bachelor of Fine Arts in painting in 1967 and worked for a time at United States Steel as a draftsman. However, because he had schizophrenia and had to take constant medication to avoid psychosis and delusions, he was unable to keep in steady employment or to develop his artistic career as he wanted. He eventually moved to West Virginia, where he met his wife Loretta and found a position as an artist-in-residence in Fairmont. In 1996, he was diagnosed with lung cancer and he died July 26, 1997, at the Fairmont General Hospital.
The Kolakoski sequence
Definition of sequence
This sequence of integers was first discussed by the professional mathematician Rufus Oldenburger in 1939, but attracted little attention at that time. It consists of an infinite series of 1s and 2s that begins like this:
1,2,2,1,1,2,1,2,2,1,2,2,1,1,2,1,1,2,2,1,2,1,1,2,1,2,2,1,1,...
Each symbol occurs in a "run" of either one or two consecutive terms and writing down the lengths of these runs gives exactly the same sequence:
1,2,2,1,1,2,1,2,2,1,2,2,1,1,2,1,1,2,2,1,2,1,1,2,1,2,2,1,1,2,1,1,2,1,2,2,1,2,2,1,1,2,1,2,2,...
1, 2 , 2 ,1,1, 2 ,1, 2 , 2 ,1, 2 , 2 ,1,1, 2 ,1,1, 2 , 2 ,1, 2 ,1,1, 2 ,1, 2 , 2 ,1,1, 2 ,...
Conversely, one can say that each term of the Kolakoski sequence generates a run of one or two future terms. The first 1 of the sequence generates a run of "1", i.e. itself; the first 2 generates a run of "22", which includes itself; the second 2 generates a run of "11"; and so on. This animation illustrates the process:
Kolakoski's role in popularizing the sequence
William Kolakoski devised the sequence independently of Oldenburger and introduced it to his fellow students while at the Carnegie Institute of Technology. He submitted it to the American Mathematical Monthly (AMM) and it was published as "Advanced Problem 5304" in the following form:
5304. Proposed by William Kolakoski, Carnegie Institute of Technology
Describe a simple rule for constructing the sequence
1 2 2 1 1 2 1 2 2 1 2 2 1 1 2 1 1 2 2 1 2 1 1 2 1 2 2 1 1 2 1 1 2 1 2 2 1 2 2 1 1...
What is the nth term? Is the sequence periodic? (AMM, Vol. 72, No. 6, June–July 1965)
It was then called the Kolakoski sequence as mathematicians investigated it further.
Analysis by mathematicians
Despite the simplicity with which the sequence can be described and generated, it poses several interesting and complex mathematical problems, some of which remain unsolved after more than fifty years of analysis. Until almost the end of his life, Kolakoski himself was not aware of how much attention it had received from professional mathematicians after he had published notice of it in the AMM. However, he eventually received a letter from an architect called William Huff that mentioned the sequence. The letter prompted Loretta Kolakoski to ask her husband's friend Mike Vargo, a writer who had first met him at CIT, to carry out further research when Kolakoski was in hospital during his final illness. Vargo discovered many references to the Kolakoski sequence on the internet and was able to inform his friend before Kolakoski died. Vargo felt that Kolakoski had been quietly pleased by the news, feeling that it vindicated his belief in the importance and beauty of the sequence.
Personal significance of sequence to Kolakoski
Because he had schizophrenia, Kolakoski was preoccupied with the topics of free will and determinism throughout his life. Despite his high intelligence and ability to master many different skills with little effort, his illness was, in the words of Mike Vargo, "this thing living within him that was always threatening to literally take over his mind and transport it into regions of chaos and delusion." While wanting to feel himself free, Kolakoski was well aware that he could not control his own brain without pharmaceutical help and was forced to accept determinism. Vargo therefore deduced that his friend searched for a benevolent order in the universe, of which the Kolakoski sequence was one possible expression. The sequence is entirely deterministic, yet behaves in an unpredictable and strangely beautiful way. Kolakoski continued to explore the sequence for many years, creating a corpus of material that is now held as the William Kolakoski Collection at Carnegie Mellon University Libraries and overseen by the mathematician Clark Kimberling.
References
External links
The William Kolakoski Collection at Carnegie Mellon University Libraries
1944 births
1997 deaths
20th-century American artists
Carnegie Mellon University alumni
People with schizophrenia
Recreational mathematicians
People from Pittsburgh
People from Fairmont, West Virginia | William Kolakoski | [
"Mathematics"
] | 1,363 | [
"Recreational mathematics",
"Recreational mathematicians"
] |
54,550,764 | https://en.wikipedia.org/wiki/Saraswati%20Supercluster | The Saraswati Supercluster is a massive galaxy supercluster about 1.2 gigaparsecs (4 billion light years) away within the Stripe 82 region of SDSS, in the direction of the constellation Pisces. It is one of the largest structures found in the universe, with a major axis in diameter of about 200 Mpc (652 million light years). It consists of at least 43 galaxy clusters, and has the mass of , forming a galaxy filament.
Discovery
The Saraswati supercluster was discovered by a team of astrophysicists from the Inter-University Centre for Astronomy and Astrophysics and Indian Institute of Science Education and Research led by Joydeep Bagchi and colleagues in Pune, India in 2017.
Analyzing the data of Stripe 82 of the comprehensive Sloan Digital Sky Survey, particularly the sets of LOWZ data from the Baryon Oscillation Spectroscopic Survey, part of the DR12 catalogue of the SDSS, the team discovered an overdensity of the sampled 625 galaxies from LOWZ and 3,016 from the LEGACY-BOSS-SOUTHERN, a survey of the southern sky that is also a part of SDSS DR12.
It was named after the Hindu goddess of knowledge Saraswati, as well as the mythological Sarasvati river; since the Sanskrit name also means “ever flowing stream with many pools”, and the supercluster has many clusters and groups moving and merging together.
Cosmology
The Saraswati Supercluster is one of the largest and most massive superclusters known, comparable to the massive Shapley Concentration in the nearby universe. The supercluster consists of 43 massive galaxy clusters, the most massive being Abell 2631 and ZwCL 2341.1+0000 respectively. It is surrounded by a network of galaxy filaments, clusters, and voids.
The Saraswati supercluster and its environs reveal that some extreme large-scale, prominent matter density enhancements had formed in the past when dark energy had just started to dominate structure formation. This galactic concentration sheds light on the role of dark energy and cosmological initial conditions in supercluster formation.
References
Galaxy superclusters
Astronomical objects discovered in 2017 | Saraswati Supercluster | [
"Astronomy"
] | 468 | [
"Pisces (constellation)",
"Astronomical objects",
"Constellations",
"Galaxy superclusters"
] |
54,551,313 | https://en.wikipedia.org/wiki/Zurich%20Notebook | The Zurich Notebook is one of Albert Einstein's notebooks, from his time in Zürich. It contains much of the basic work for general relativity.
References
20th-century manuscripts
German-language manuscripts
Notebooks
Culture of Zurich
Science and technology in Switzerland
Works by Albert Einstein
General relativity | Zurich Notebook | [
"Physics"
] | 57 | [
"General relativity",
"Relativity stubs",
"Theory of relativity"
] |
54,551,486 | https://en.wikipedia.org/wiki/Super-resolution%20dipole%20orientation%20mapping | Super-resolution dipole orientation mapping (SDOM) is a form of fluorescence polarization microscopy (FPM) that achieved super resolution through polarization demodulation. It was first described by Karl Zhanghao and others in 2016. Fluorescence polarization (FP) is related to the dipole orientation of chromophores, making fluorescence polarization microscopy possible to reveal structures and functions of tagged cellular organelles and biological macromolecules. In addition to fluorescence intensity, wavelength, and lifetime, the fourth dimension of fluorescence—polarization—can also provide intensity modulation without the restriction to specific fluorophores; its investigation in super-resolution microscopy is still in its infancy.
History
In 2013, Hafi et al. developed a novel super-resolution technique through sparse deconvolution of polarization-modulated fluorescent images (SPoD). Because the fluorescent dipole is an inherent feature of fluorescence, and its polarization intensity can be easily modulated with rotating linear polarized excitation, the polarization-based super-resolution technique therefore holds great promise with regard to a wide range of biological applications due to its compatibility with conventional fluorescent specimen labeling. The SPoD data, consisting of sequences of diffraction-limited images illuminated with varying linearly polarized light, were reconstructed with a deconvolution algorithm termed SPEED (sparsity penalty – enhanced estimation by demodulation). Although super resolution can be achieved, the dipole orientation information is lost during SPoD reconstruction.
In 2016, Keller et al. argue that the improvement in resolution observed with the SPoD method is a deconvolution effect. That is, the super-resolution in the images that Hafi shows is achieved by SPEED algorithm not the SPoD method. So the polarization information does not contribute substantially to the final image. They concluded that polarization can't add further super-resolution information.
At the same time, Waller et al. replied to the debate and they admit the question raised by Keller. They did some new experiments to support SPoD could bring further information. They prove that raw modulation information in SPoD also separated sub-diffractional details without SPEED. However, whether it works for heterogeneously and densely labeled samples is unsure and still need further studies.
Afterwards, Karl Zhanghao et al. proposed a new approach called SDOM that resolves the effective dipole orientation from a much smaller number of fluorescent molecules within a sub-diffraction focal area. They also applied this method to resolve structural details in both fixed and live cells. Their results showed that polarization does provide further structural information on top of the super-resolution image, thereby providing a timely answer to the key question raised by the debate mentioned above.
Fluorescence polarization microscopy
As a fundamental physical dimension of fluorescence, polarization has been applied extensively in biological research. Through fluorescence polarization microscopy (FPM), the dipole orientation as well as the intensity of fluorescent probes could be measured. Compared with X-ray crystallography or electron microscopy which could elucidate ultra-high resolution of individual proteins or macromolecule assemblies, FPM doesn't require complex sample preparation which makes it suitable for live cell imaging. Near-field imaging techniques, such as Atomic Force Microscopy (AFM) could also provide structural information, which however, is limited only to samples on the surface. FPM is capable of imaging orientations in dynamic samples at the time scale of seconds or milliseconds, thus it can serve as a complementary method for the measurement of subcellular organelle structures.
FPM has been evolving over the past decades, from manual or mechanical switching of polarization detection or excitation to simultaneously detection and fast polarization modulation via electro-optic devices. With faster imaging speed and higher imaging quality, FPM has been incorporated with various imaging modalities, such as wide-field, confocal microscopy, two-photon confocal, total internal reflection fluorescence microscope, FRAP, etc. However, as an optical imaging technique, the development of fluorescence polarization microscopy (FPM) is barricaded by the diffraction limit. Compared to the abundant super-resolution techniques on fluorescence intensity imaging, super-resolution techniques in FPM are still in its infancy.
Recently, three forms of FPM have emerged and it has been proved that they can achieve super-resolution. They are SPoD, SDOM and polar-dSTORM (polarization-resolved direct stochastic optical reconstruction microscopy).
Polar-dSTORM used On-Off modulation of the fluorescent probes and acquired adequate frames for a reconstruction of super resolution image. The imaging resolution of polar-dSTORM is high, with localization precision in tens of nanometers. Single dipole average orientation is directly measured separately and the wobbling angle is statistically calculated from neighboring emitters. The drawback of polar-dSTORM is a long imaging time of 2–40 min, which requires a stationary sample during the imaging period. The sample preparation of dSTORM also makes it hard for live cell samples.
SDOM has achieved super resolution dipole orientation mapping with a spatial resolution of 150 nm and sub-second temporal resolution. It has been applied to both fixed cell and live cell imaging, which shows great advantages over diffraction limited FPM techniques on both revealing sub-diffractional structures and measuring local dipole orientations. In comparison with polar-dSTROM, SDOM still measures average dipoles and could not separate the signal of the wobbling of single fluorophores from the variation of orientation distribution of fluorophores with the resolvable area. As with SPoD, the power of SDOM would be weakened if the fluorescent probes are distributed too homogeneously or too dense.
Thanks to the intrinsic polarization of chromophores, fluorescence polarization reveals the structures and functions of the biological macromolecules. With incorporation with various optical imaging modalities, FPM has played an irreplaceable role in solving many questions. Fast and non-invasive imaging of the samples makes it a complementary tool for X-crystallography which typically applies to individual proteins, or sub-complexes, or EM which requires invasive sample preparation, or AFM which could measure the surface of the sample. Compared to these methods, the specific labeling of the fluorescent probes provides better focus on the structure of interest.
As the development of FPM techniques, its power has spread from uniform oriented fluorophores to fluorescent dipoles with organized orientation or on complex bio-structures. The detection accuracy has improved from measuring the bulk volume polarization to sub-diffraction area measurement and single dipole measurement. Imaging resolution of FPM matters not only for intensity image but also for the accuracy of dipole orientation detection. Recently developed super resolution FPM techniques still have their limitations though demonstrating great successes in their imaging results. Spatial 3D super resolution FPM techniques and 3D orientation measurement of fluorescent dipoles are still missing. In the future, more inventions are anticipated which could achieve both high-resolution measurement and fast temporal resolution, allowing imaging samples of live cells. This may be done by introducing existing super resolution principles into FPM, or by better exploiting the intensity fluctuation with polarization modulation, or other alternative means.
Principle of SDOM
Unlike other super-resolution methods, such as STED, SIM, PLAM and STORM, SDOM can achieve super-resolution based on a wide-field epi-fluorescence illumination microscope. The key point of SDOM is polarized excitation. The SDOM imaging system can be seen in figure A. The rotary linear polarized excitation is realized by continuously rotating a half-wave plate in front of a laser. Then, the illumination beam is focused onto the back focal plane of the objective to generate uniform illumination with rotating polarization light. The series of fluorescence images excited from different angles of polarized excitation are collected by an EMCCD camera.
All organic fluorescent dyes and fluorescent proteins are dipoles, whose orientations are closely related to the structure of their labeled target proteins. Because both the excitation absorption and fluorescence emission of dipoles have polarization features, FPM has been widely used to study dipole orientation. As illustrated in the inset schematic figure B, the fluorophores (such as GFP) are linked to the target protein via the C terminus (connected to GFP's N terminus), and the dipole angle of the fluorophore will reflect the orientation of the target protein. Therefore, the SDOM can be used to study the structure of the protein.
Figure C illustrates the principle of the SDOM super-resolution technique. Two neighboring fluorophores with 100 nm distance and different dipole orientations (pseudocolor in red and green) emit periodic signals excited by rotating polarized light. By rotating the polarization of excitation, the emission ratio between the two molecules is modulated accordingly, resulting in their separation in the polarization domain. The sparsity deconvolution can achieve a super-resolution image of effective dipole intensities under polarization modulation; with least-squares fitting, the dipole orientation can be determined. Arrows indicate the directions of dipole orientations. The super-resolution was achieved in the polarization domain.
The SDOM result of two intersecting lines is shown in figure D, with arrows on top of the super-resolution image, illustrating the dipole orientation. Figure E shows the corresponding data are represented in (X, Y, θ) coordinates, in which the XY plane is the super-resolved intensity image. From both D and E, we can see that as SDOM introduces a new dimension, the molecules that are not able to be resolved in the super-resolution intensity image can be completely separated in the dipole orientation domain.
References
Microscopy | Super-resolution dipole orientation mapping | [
"Chemistry"
] | 2,049 | [
"Microscopy"
] |
54,551,494 | https://en.wikipedia.org/wiki/Cortobenzolone | Cortobenzolone (brand name Tuplix), also known as betamethasone salicylate, is a synthetic glucocorticoid corticosteroid and corticosteroid ester which is marketed in Spain.
References
Corticosteroid esters
Organofluorides
Glucocorticoids
Pregnanes
Prodrugs
Salicylate esters
Tetrols
3-Hydroxypropenals | Cortobenzolone | [
"Chemistry"
] | 97 | [
"Chemicals in medicine",
"Prodrugs"
] |
54,551,943 | https://en.wikipedia.org/wiki/HD%20183143 | HD 183143 (HT Sagittae) is a blue hypergiant star located in the constellation of Sagitta.
This star has an apparent magnitude of 6.9, meaning that cannot be seen with the naked eye, but is an easy target for binoculars or a small telescope.
Observations
HD 183143 was included in the first catalogue of Be stars, with distinct Hα emission lines. When emission lines in hot supergiant stars were investigated as indicators of expanding atmospheres and mass loss, HD 183143 was found to have Hα lines with P Cygni profiles, but indications of only modest mass loss. Modern high-resolution spectra show emission in lines from Hα, Hβ, Hγ, and Hδ, formed by the strong stellar wind.
The introduction of spectral standards for supergiants gave HD 183143 as the standard star for the class B7Ia. The spectral type is sometimes given as B7Iae to indicate the presence of the emission lines.
HD 183143 was listed as being variable in 1976, with a very small amplitude. During the Hipparcos mission, its brightness was observed to vary between magnitude 6.71 and 6.95. ASAS-3 photometry shows a period of 40.44 days. HD 183143 was formally announced as a variable star, probably of the α Cygni type, in 1979 and given the variable star designation HT Sagittae.
HD 183143 has been extensively studied because of the diffuse interstellar bands visible in its spectrum. The strongest lines are caused by interstellar atomic iron, potassium, lithium, sodium, and calcium, as well as ionised calcium, and CH and CN molecules. Infrared bands of ionised buckminsterfullerene have also been found in its spectrum. HD 183143 has been proposed as a reference standard for interstellar polarisation. It shows 6% polarisation.
A 2004 study reclassified the spectral type of HD 183143 as B6.8 Ia-0, a hypergiant. The parallax from the original Hipparcos catalogue was 2.70 mas, indicating a distance around 370 pc, but the revised Hipparcos parallax and the Gaia Data Release 3 parallax both indicate distances around 2,000 pc. Comparison of the space velocity and interstellar spectral lines produce a similar distance, with the star lying between the Orion-Cygnus Arm and the Carina–Sagittarius Arm. At that distance, HD 183143 is an extremely luminous star, around , with correspondingly high mass and radius.
See also
Zeta1 Scorpii
Cygnus OB2#12
Rigel
References
Sagitta
Sagittae, HT
Durchmusterung objects
183143
095657
B-type hypergiants
Alpha Cygni variables | HD 183143 | [
"Astronomy"
] | 571 | [
"Sagitta",
"Constellations"
] |
54,551,950 | https://en.wikipedia.org/wiki/Shock%20synthesis | Shock synthesis is the process of complex organic chemical creation through high velocity impact on simple amino acids, theorized to take place when a comet strikes a planetary body, or through the shock-wave created by a thunder clap. Hyper-velocity impact shock of a typical comet ice mixture produced several amino acids after hydrolysis. These include equal amounts of D- and L-alanine, and the non-protein amino acids α-aminoisobutyric acid and isovaline as well as their precursors.
References
Origin of life
Amino acids | Shock synthesis | [
"Chemistry",
"Biology"
] | 110 | [
"Amino acids",
"Biomolecules by chemical classification",
"Origin of life",
"Biological hypotheses"
] |
54,552,667 | https://en.wikipedia.org/wiki/Nursing%20care%20bed | A nursing care bed (also nursing bed or care bed) is a bed that has been adapted to the particular needs of people who are ill or disabled. Nursing care beds are used in private home care as well as in inpatient care (retirement and nursing homes).
Construction and functionality of nursing care beds
Typical characteristics of nursing care beds include adjustable lying surfaces, adjustable heights up to at least 65 cm for ergonomic care, and lockable castors with a minimum diameter of 10 cm. Multi-sectioned, often electronically powered lying surfaces can be adjusted to fit a variety of positions, such as comfortable sitting positions, shock positions or cardiac positions. Nursing care beds are also often equipped with pull-up aids (trapeze bars) and/or cot sides (side rails) to prevent falls.
Thanks to its adjustable height, the nursing care bed allows for both an ergonomic working height for nurses and healthcare therapists as well as a range of suitable positions allowing easy access for the resident.
Specifications for nursing care beds
The development, manufacture and sale of nursing care beds are subject to the following regulations:
ISO 14971 Medical devices. Risk analysis (see risk management)
IEC 60601-1 Medical electrical equipment
IEC 60601-2-38
IEC 60601-2-52
93/42 EEC Directive medical devices
89/336 EEC Electromagnetic compatibility
Special nursing care beds
Bed-in-bed
Bed-in-bed systems offer the option to retrofit the functionality of a nursing care bed into a conventional bed frame. A bed-in-bed system provides an electronically adjustable lying surface, which can be fitted into an existing bed frame replacing the conventional slatted frame. This enables the nursing care bed functionality to be fully integrated into the familiar bedroom furniture.
Hospital bed
Hospital beds provide all of the basic functions of a nursing care bed. However, hospitals have stricter requirements regarding hygiene as well as stability and longevity when it comes to beds. Hospital beds are also often equipped with special features (e.g. holders for IV devices, connections for intensive care, etc.).
Lie-low bed
This version of the nursing care bed allows the lying surface to be lowered close to the floor to prevent injury from falls. The lowest bed height in the sleeping position, usually about 25 cm above floor level, combined with a roll-down matt that can be placed at the side of the bed if needed – minimises the risk of injury if the resident falls out of the bed. Lie-low beds provide a viable alternative to conventional measures used in caring for restless residents by foregoing legally problematic restrictive measures (cot sides, fixation devices).
Ultra-low bed / floor bed
This is a further adaptation of the lie-low bed, with a lying surface that can be lowered to less than 10 cm above floor level, which ensures that the risk of injury is minimised if the resident falls out of the bed, even without a roll-down matt. In order to maintain and promote mobility, the particularly low height gives residents with limited motor ability the chance to independently return to bed by moving around on all fours, for example.
Intelligent nursing care bed / smart bed
Nursing care beds with technical equipment including sensors and notification functions are known as “intelligent” or “smart” beds.Such sensors in intelligent nursing care beds can, for example, determine whether the user is in the bed, record the resident's movement profile or register damp in the bed. Those measurements are transmitted to the care givers via cables or wirelessly. The beds are connected to alarm functions and help care givers to assess the need for action.Intelligent beds should contribute to improved care quality. For example, the documented sensor data regarding the intensity of movement in bed can help care givers recognise and make decisions about whether a resident should be moved to prevent bedsores.
References
Bibliography
Johansson, Charity, "Mobility in Context: Principles of Patient Care Skills", (F.A. Davis, 2012).
Beds
Nursing | Nursing care bed | [
"Biology"
] | 814 | [
"Beds",
"Behavior",
"Sleep"
] |
54,552,684 | https://en.wikipedia.org/wiki/Shand%20Mason | Shand Mason was a British company which designed and manufactured steam powered fire engines and other fire-fighting equipment during the 19th century and early 20th centuries.
History
The company that eventually became Shand Mason was founded in 1760 by Samuel Phillips, and incorporated as Phillips and Hopwood in 1797. In 1818, after William Joshua Tilley had joined the business, it became Hopwood and Tilley and later Tilley & Co. In 1850, when Tilley retired from the business, his two sons-in-law James Shand and Samuel Mason continued the business as Shand and Mason, later Shand Mason & Co.
The company operated from premises at 75 Upper Ground Street, Blackfriars, just south of the River Thames in London, and having initially manufactured manually operated pumps, secured various patents to improve the design and construction of steam fire engines.
While the first steam-powered fire engine had been developed by John Braithwaite and John Ericsson in 1829, the first commercially successful fire-engine was a water-borne version developed by Shand Mason & Co, which went into service in 1855. From this point and particularly from the 1860s, the company worked with the chief of the Metropolitan Fire Brigade, Eyre Massey Shaw and with competitor Merryweather & Sons, to perfect designs for land-based use by the London brigade and other municipalities. Its first land-based engine used by the brigade was produced in 1860.
Its engines were initially horse-drawn, but later installed on fireboats (Europe's first, the Fire Queen was built by Shand Mason for service in Bristol's docks in the 1880s), and mounted on motor vehicles. The business was eventually taken over by Merryweather & Sons in 1928.
References
Firefighting equipment
Steam power
1760 establishments in England
British companies established in 1760
Manufacturing companies established in 1760 | Shand Mason | [
"Physics"
] | 368 | [
"Power (physics)",
"Steam power",
"Physical quantities"
] |
54,553,783 | https://en.wikipedia.org/wiki/ARP%20cache | An ARP cache is a collection of Address Resolution Protocol entries (mostly dynamic), that are created when an IP address is resolved to a MAC address (so the computer can effectively communicate with the IP address).
An ARP cache has the disadvantage of potentially being used by hackers and cyberattackers (an ARP cache poisoning attack). An ARP cache helps the attackers hide behind a fake IP address. Beyond the fact that ARP caches may help attackers, it may also prevent the attacks by "distinguish[ing] between low level IP and IP based vulnerabilities".
References
Address Resolution Protocol
Computer network technology | ARP cache | [
"Technology"
] | 131 | [
"Computing stubs",
"Computer network stubs"
] |
54,554,143 | https://en.wikipedia.org/wiki/Voltage%20symmetrization%20system | Voltage Symmetrization System (VSS) was developed especially for electric power networks with great phase voltage unbalance. It is a three-phase system which enables earth-fault current and charging current elimination. Until now, the operation with earth-fault current compensation has been very complicated for the networks with a great voltage unbalance. In the past, it was necessary to operate such networks with an isolated neutral, solid grounding or with a significantly untuned arc-suppression coil. VSS can also substitute for an arc-suppression coil or it can complement it parallelly. Moreover, it contributes to a better function of earth-fault protections for high-resistance earth faults by equalizing phase-to-earth capacity unbalance. The VSS was patented.
The three-phase VSS has several basic functions:
In a faultless condition:
Symmetrization of phase voltage, i.e. elimination of phase voltage unbalance realized by controlling the phase-to-earth capacity unbalance in the network,
Reduction of charging current value, i.e. elimination of charging current of phase-to-earth capacity which contributes to reduction of reactive capacity power flow in the network.
During an earth fault:
Elimination of earth-fault current (analogous to an arc-suppression coil,
Controlling the residual active earth-fault current.
Faultless condition
If VSS is used for phase voltage unbalance elimination only, it is possible to operate it with a relatively low power. The VSS can effectively eliminate and control the phase voltage unbalance, which is caused by phase-to-ground capacity unbalance. The system enables to automatically maintain phase-to-ground capacity unbalance of the network in the range of assigned parameters, and thus provides the network with symmetrical phase voltage in the assigned range as well. In particular cases, the VSS can be used for artificial increase in phase voltage unbalance of the network, mostly for a short-time period during earth-fault localization in the network.
Reduction of charging current value in a faultless condition
If VSS is used for line's charging current elimination, it is not necessary to install shunt reactor. In single-phase cable lines, the VSS can eliminate the whole charging current because the operational capacity comprises phase-to-ground capacity only. In three-phase and overhead lines, the operational capacity comprises not only of phase-to-ground capacity but also of phase-to-phase capacity. VSS eliminates only charging currents of phase-to-ground capacity in these networks, which stands for 60% to 70% of line's operational capacity value (VSS is not designated for elimination of phase-to-phase capacity charging current in the lines). VSS contributes to a significant reduction of charging reactive power flow.
Elimination of earth-fault current during an earth fault
The advantage of the system is that it does not require a neutral to eliminate the earth-fault current. Therefore, the VSS has been implemented especially in networks which were operated with isolated neutral. During an earth fault in the network, the system eliminates earth-fault current. The function is in principle similar to an arc-suppression coil. In comparison to the arc-suppression coil, VSS eliminates earth-fault current more efficiently, even in unbalanced or extremely unbalanced networks.
Controlling the residual active earth-fault current during an earth fault
VSS enables to control the magnitude of residual active earth-fault current. This can be applied to improve the function of directional ground protection or to decrease great active earth-fault current in the network. Such quality is used in networks with great active earth-fault current value, for instance in large cable lines.
Note
As VSS does not require neutral for its connection, it can be connected anywhere in the network. At the same time, it is possible to adjust its power to a certain part of the network only, which can be use in local distribution networks or in long feeders, in feeders with high value of charging current, or in feeders with high capacity unbalance. The part of the network in which VSS is installed does not increase the value of phase-to-earth capacity current in power supply network. Furthermore, the value of network's charging current decreases by the set system power. The VSS is very beneficial in networks with island operation. In island operation, the source is not loaded by charging current of the line and the separated island area is operated with resonant grounding. Such qualities cannot be reached with a classic arc-suppression coil.
Operational experience of VSS since 2005
VSS systems have been installed in industrial 6 kV networks as well as in standard distribution networks up to 35 kV. Operational experience proved that VSS can eliminate even extremely high cross parameters unbalance in the network without negatively influencing the function of earth fault protection. Thanks to elimination of phase capacity unbalance, high reliability of directional ground protection can be reached even with high-resistance earth-faults. The possibility of operating the network with accurately compensated phase-to-earth capacity currents contributes to higher safety of the network operation.
References
European Patent EP 1817829
Power engineering | Voltage symmetrization system | [
"Engineering"
] | 1,045 | [
"Power engineering",
"Electrical engineering",
"Energy engineering"
] |
54,554,237 | https://en.wikipedia.org/wiki/Fei-Yue%20Wang | Fei-Yue Wang (; born November 1961) is a specially appointed state expert, and the Chief Scientist and Founding Director of the State Key Laboratory for Management and Control of Complex Systems of the Chinese Academy of Sciences. He is editor-in-chief of the IEEE Transactions on Computational Social Systems and the IEEE/CAA Journal of Automatica Sinica. Previously he was a Professor of Systems and Industrial Engineering at the University of Arizona, president of the IEEE Intelligent Transportation Systems Society, editor-in-chief of IEEE Transactions on Intelligent Transportation Systems (2009–2016), and editor-in-chief of IEEE Intelligent Systems.
Wang was elected as a Fellow of the IEEE in 2004 "for contributions to intelligent control systems and applications to complex systems". He became a fellow of the American Association for the Advancement of Science and the ASME in 2007. In 2011 he won the Outstanding Research Award of the IEEE Intelligent Transportation Systems Society, and in 2014 he was given the Norbert Wiener Award of the IEEE Systems, Man, and Cybernetics Society "for fundamental contributions to and innovations in the theory and application of intelligent control and management to complex systems."
References
External links
Living people
1961 births
Intelligent transportation systems
Fellows of the IEEE
Fellows of the American Association for the Advancement of Science | Fei-Yue Wang | [
"Technology"
] | 257 | [
"Warning systems",
"Intelligent transportation systems",
"Information systems",
"Transport systems"
] |
54,555,970 | https://en.wikipedia.org/wiki/Telling%20Lies%20%28video%20game%29 | Telling Lies (stylized as telling l!es) is a narrative video game developed by Sam Barlow and Furious Bee and published by Annapurna Interactive in August 2019 for iOS, macOS, and Windows. Ports for Nintendo Switch, PlayStation 4, and Xbox One were released in April 2020. As with Barlow's previous title, Her Story, the game uses live action full-motion video of four people (played by Logan Marshall-Green, Alexandra Shipp, Kerry Bishé, and Angela Sarafyan) as part of video calls made between them, and the player will need to use tools provided from the game to piece together events and what statements may be lies to determine the overall mystery.
Gameplay
Barlow describes Telling Lies as a "desktop thriller" like Her Story, where the player becomes involved in a drama that is played out through stored video clips and other information presented on a virtual computer desktop. Telling Lies provides the player with numerous video segments that in the game's narrative, cover a two-year period and which have been stored on a stolen hard-drive taken from the National Security Agency. The player has the ability to search the hundreds of video segments on keywords as to piece together timelines, events, and interactions, all to try to understand why the four central people have been the subject of electronic surveillance, as well as the nature of the player-character's role in these events; this character appears female and can be seen in a virtual reflection of the in-game computer screen to the actual player. These clips only provide the video and audio from one side of the conversation, requiring the player to determine which clips may match the other participants, as well as potential interactions with around 30 other people. Players can scroll forwards and backwards within segments, highlight certain words in the video subtitles to use as search, and keep notes within an in-game memo pad. The player only has a limited amount of time within a single playthrough to scan material from the hard-drive, and would have to restart from scratch (losing all notes and bookmarks) if they want to see more. Barlow estimated that the content within Telling Lies is about four to five times longer than Her Story. There are three different endings that the player may reach through the game, depending on which character's videos they explored most frequently.
The game also contains a version of solitaire. The deck lacks the king of clubs and is therefore unwinnable.
Plot
In 2019, Karen Douglas, a former FBI agent, accesses a USB drive on her computer, watching the videos on it by searching them using keywords.
They tell the story of David Smith, an FBI agent. During 2017 and 2018, David was undercover, supervised by his handler Mike, working on a case code-named Green Dagger. Its goal was to investigate potential acts of terrorism by the environmental group "Green Storm", led by the activist Riordan. To infiltrate this group, David would start by infiltrating a smaller team, the "Organizing Group", which targeted the corporation Prosperen, due to its plans to build a pipeline which the activists believed would pollute the water source. David approached one of the group's members, Ava, and developed a romantic relationship with her, eventually being invited to the Organizing Group.
The Organizing Group was led by 4 people: Eric, Chris, Peter, and Simon. Simon was secretly a Black Kite agent providing information to the FBI, an arrangement David was unhappy with as he felt Simon was unprofessional. As David ingratiated himself with the group, he discovered that Peter had previously slept with Ava while she was underage, drugged her and filmed their relations. David attacks Peter, angering Ava and the FBI, and then uses a former contact named Harry to plant drugs on Peter, framing him. David grows increasingly unstable, and outs Simon as a Black Kite Spy. These actions and his growing closeness to Ava alarm Mike. David invites Riordan and the Organizing Group to a meeting on his boat, to discuss plans to disrupt movement on a key bridge vital for Prosperen's plans. While on the boat, Ava reveals that she is pregnant with David's child.
A new Black Kite spy infiltrates Green Storm, and David coordinates with him to trap Riordan into getting involved in a direct attack on the bridge. The plan goes awry, and David discovers that Mike and Black Kite have decided to hold off on Green Storm, and arrest the Organizing Group. David protests, but fails to persuade Mike, who tells him to end his infiltration. The Organizing Group is then arrested, including Ava. David is angry at Mike, but Mike notes that David had been withholding information, including Ava's pregnancy. David tries to continue meeting with the Organizing Group, but Karen Douglas, his then-field supervisor, bursts in to provide him cover to leave. David is furious, but agrees to withdraw. Ava is heartbroken and outraged at David's disappearance.
Meanwhile, David has problems with his wife Emma and daughter Alba. While David was undercover, Emma’s mother Laura moved in. During David's mission, Laura developed dementia and passed away, despite medical care by Steven, an anaesthesiologist hired by the couple. In addition, it is revealed that when David was Emma's boyfriend, he killed Paul, Emma’s abusive ex-boyfriend, with Emma as an unwilling accomplice.
To cope with stress, David had been having conversations with a sex worker named Maxine Williams, who ran a webcam chatroom with multiple aliases. David paid her for conversation, and shared personal stories with Maxine, including his identity. As his life falls apart, David begins believing he has a real connection with Maxine. She bans him, and when he keeps returning, reveals that everything he knows about her is a lie, and that she has recorded their conversations, and will release them if he keeps following her. David tracks her down with Harry's help. Maxine is prepared, has already released the videos, and shoots David in the leg, as police arrives.
This destroys his relationship with Emma, who had grown scared of him. David begins living alone, estranged from his wife and Ava. He tries to reconnect with them, but both reject him. David commits suicide by detonating explosives on his boat, potentially destroying the bridge. After reviewing the videos, Karen leaks them.
The mid-credits scene shows Emma’s, Ava’s, or Maxine’s fate, depending on the videos the player has watched. Both Emma and Ava move on to a new life without David and continue to raise their daughters. Maxine leaves her place in Cleveland, Ohio and opens a cam agency in New York, going on to become a novelist writing crime stories with ‘strong female leads’.
Development
Barlow's work on Telling Lies began in January 2016 as a "spiritual successor" to Her Story, with a narrative unrelated to the first game, though it continued to use full-motion video as its central gameplay element. Through some had urged him to make a direct sequel to Her Story by creating another murder mystery and putting another actor in place, Barlow wanted something that was more risky, and utilising the aspects of Her Story where the player got to know more about the main character through the clips. He came to the concept of electronic surveillance as a central theme in part of being a parent himself and wanting to keep track of his own pre-teen-aged son's online activities. In reading up about surveillance methods used by the National Security Agency and MI5, Barlow read up on the Optic Nerve program and found that it had several similarities to Her Story, including the ability to search on stored video and audio through keywords.
In July 2017, Barlow announced that the game, titled Telling Lies, would feature three to four key characters. He described the game as a combination of the films The Conversation (1974) and Shame (2011). The game was published by Annapurna Interactive and shooting for the game had been scheduled to start in late 2017 or early 2018. For filming, Barlow wanted the conversations between characters to appear natural, ideally filming both actors as they conversed but from different locations. To accomplish this, they were able to rent out a compound that had a number of different homes and buildings that they could make appear like the different locations that were called for in the script, including scenes where they were moving about the compound. In this fashion, the actors recorded their lines in their separate locations over video conferencing calls, with Barlow and other directors running between the sets as needed to provide direction. The shooting was done mostly in chronological order of the narrative story, with over 100 hours of footage captured. Only about ten hours of this were used for the game itself.
By March 2019, Barlow released the game's first trailer. The game was subsequently released on 23 August 2019 for iOS devices, and Windows and macOS personal computers. Console ports to PlayStation 4, Xbox One and Nintendo Switch were scheduled for release on 28 April 2020.
Reception
Telling Lies received an aggregated score of 84/100 on Metacritic, indicating "generally favorable reviews". GamesRadar+ said that the exploration of footage felt "totally organic and beautifully paced", and that "Sam Barlow has another masterpiece on his hands." Kotaku praised the story and acting, saying that "the cast of Telling Lies is uniformly excellent, delivering performances far beyond anything I've seen in an FMV game." US Gamer said that in terms of "good interactive mysteries, Telling Lies is among the best you can get." PC Gamer said "the core concept—an open-ended story that's revealed in a different way to every person who plays the game—is still enormously compelling". IGN found the user interface to be somewhat unintuitive, but said that "every one of its short video clips is packed with meaning, and working out where you should go next is rewarding because each subplot is gripping." Game Informer praised the game's freedom to explore the story and the psychology of the characters, saying that "once I discovered the answers to the central mystery, I didn't stop playing – I continued to find every bit of video content I could because I was enthralled by the people in this world." The Telegraph celebrated the game's interactivity as it takes you through a mystery thriller. The Guardian praised it as an expansion of concepts in Her Story, saying that the game "doesn't hold your hand, and ultimately it's down to you to decide the truth – another secret of a good mystery done well." EGM also complimented its shift from the murder mystery in Her Story to a political thriller, calling it "a thought-provoking look at the modern surveillance state—delivered not through soapbox lecture but by forcing you, unsettlingly, to participate."
Calling it "one of the most brilliant games of the year", The Washington Post said the game "works its magic by making you rethink things you hadn't thought to question", its "crafted voyeurism should inspire the creep in you." Rock Paper Shotgun called it "bigger, better, faster, stronger" than Her Story, while saying that the nature of the found video made the game feel more voyeuristic. Eurogamer felt that its experiment with storytelling was flawed as "a little wobbly, a little naive," but also "courageous and exciting".
Hardcore Gamer was critical of the game compared to Her Story, saying that "Telling Lies does not hit the same emotional highs". GameSpot criticized the lack of structure, saying "the mechanics, writing, and performances create a real feeling of peering into someone else's private world all the way through, but the game doesn't give you much in the way of agency."
Awards
References
External links
2019 video games
2010s interactive fiction
Annapurna Interactive games
IOS games
MacOS games
Nintendo Switch games
PlayStation 4 games
Single-player video games
Video games about computing
Video games developed in the United Kingdom
Windows games
Xbox One games
Interactive movie video games
Full motion video based games
Video games directed by Sam Barlow | Telling Lies (video game) | [
"Technology"
] | 2,497 | [
"Works about computing",
"Video games about computing"
] |
77,499,416 | https://en.wikipedia.org/wiki/NGC%202528 | NGC 2528 is an intermediate spiral galaxy in the constellation of Lynx. Its velocity with respect to the cosmic microwave background is 4098 ± 12 km/s, which corresponds to a Hubble distance of 60.45 ± 4.23 Mpc (∼197 million light-years). It was discovered by French astronomer Édouard Stephan on 22 January 1877.
NGC 2528 is a luminous infrared galaxy (LIRG). According to the SIMBAD database, NGC 2528 is classified as a radio galaxy.
One supernova has been observed in NGC 2528: SN 2023jo (type IIn, mag. 17.5) was discovered by ATLAS on 13 January 2023.
NGC 2415 group
NGC 2528 is a member of the NGC 2415 group (also known as LGG 148) which includes NGC 2415, NGC 2444, NGC 2445, NGC 2476, NGC 2493, NGC 2524, UGC 3937 and UGC 3944.
See also
List of NGC objects (2001–3000)
References
External links
2528
022805
04227
08040+3920
+07-17-015
Lynx (constellation)
18770122
Discoveries by Édouard Stephan
Intermediate spiral galaxies
Radio galaxies
Luminous infrared galaxies | NGC 2528 | [
"Astronomy"
] | 255 | [
"Lynx (constellation)",
"Constellations"
] |
77,506,133 | https://en.wikipedia.org/wiki/3-Phenoxymandelonitrile | 3-phenoxymandelonitrile (also 3-phenoxy-α-cyanobenzyl alcohol) is an organic compound belonging to the group of cyanohydrins. It is primarily used in the synthesis of pyrethroids, a class of insecticides.
Production
The synthesis of 3-phenoxymandelonitrile begins with the reaction of 3-phenoxybenzaldehyde with sodium cyanide and acetic anhydride in a water/dichloromethane mixture, using benzyltriethylammonium chloride as a phase transfer catalyst. This reaction initially produces the acetate, which can be hydrolyzed enzymatically with a suitable lipase to yield enantiomerically pure (S)-3-phenoxymandelonitrile through chiral resolution. The desired product can be extracted at this stage. The remaining enantiomeric acetate can undergo racemization via reaction with triethylamine in toluene or diisopropyl ether to improve yield. An alternative synthesis involves transferring a cyano group from acetone cyanohydrin to 3-phenoxybenzaldehyde. Again, enzymatic reactions through an ester can be used to produce the enantiomerically pure compound.
Use
(S)-3-Phenoxymandelonitrile serves as an important intermediate in the production of various pyrethroids, which are carboxylic acid esters incorporating the compound as an alcohol component, and are employed as insecticides. Notable examples within this group include deltamethrin and esfenvalerate. The presence of the 3-phenoxy group and nitriles enhances the efficacy of these compounds compared to other pyrethroids.
References
Benzyl compounds
Nitriles
Secondary alcohols | 3-Phenoxymandelonitrile | [
"Chemistry"
] | 386 | [
"Nitriles",
"Functional groups"
] |
77,507,182 | https://en.wikipedia.org/wiki/CyberJoly%20Drim | "CyberJoly Drim" is a cyberpunk short story by Polish author . In the story, the heroine abandons her body in favour of a digital existence. The story was first published on Liedtke's personal website in 1998 before being reprinted by Fenix magazine in 1999.
The story won the most prestigious Polish award for science fiction and fantasy stories (the Janusz A. Zajdel Award), as well as two others, but was negatively reviewed by several writers connected with the leading Polish science fiction and fantasy magazine, Nowa Fantastyka, which had rejected the story before it was submitted to Fenix. Several critics argued that it had no literary merit and criticized those who nominated it for awards or voted for it in them. Other critics praised its depiction of Internet culture, situating its criticism as a reaction to Internet culture by those unfamiliar with it, as well as arguing that some negative reviews were influenced by the reviewers dislike for the story's author, who was an outsider to the closed, male world of Polish SF literary fandom.
Plot
Jola (CyberJoly) is a computer graphic designer working on the Internet who is not enjoying her life; her husband bores her and her physical needs are unimportant. She finds fulfilment in cyberspace, where she becomes fascinated by a person with the nickname Carramba. Longing for him, she sends a humorous letter-song to a romantic website, which unexpectedly becomes a hit on the charts. Then she creates an animation that becomes even more popular. She finally meets Carramba and they get married, but her life quickly becomes mundane again. Disappointed with her life, with the help of friends she had made online, Jola decides to completely cut off herself from the physical world, donating elements of her body to the bank, keeping only her mind, which is connected to the Internet.
Background and release
Antonina Liedtke is a graduate of librarianship and information science from the University of Warsaw and worked in the library and publishing house of Warsaw University of Technology, and then in the Publishing School of Economics. She published CyberJoly Drim on her own website in 1998 and sent it to Nowa Fantastyka, the leading Polish science fiction and fantasy magazine, where it was rejected by its editor-in-chief Maciej Parowski. It was then sent to Fenix, who published it in 1999.
Reception
Awards and controversy
It won the Janusz A. Zajdel Award for best short story in 2000. It also won the ("Silver Globe") award and the On-line Award by Fahrenheit magazine. (The Zajdel award is the most prestigious Polish award for science fiction and fantasy; the two other awards were more short lived). After the story won prominent literary awards, Nowa Fantastyka published a section, "Critics about CyberJoly Drim", in the January 2001 issue. Three reviews appeared there – by Jacek Dukaj, Marek Oramus and Parowski.
Parowski wrote that "[the text] was captivating in its linguistic and situational consistency in presenting the world of Internet culture". However, he criticized its excessive length, "its mental monomania and action-oriented triviality". He considered the awarding of the Zajdel Prize to the story as the result of "promotion by a certain group" (internet users and young authors), saying that the text met the "mythological and sociological needs of a very large group of internet users".
Dukaj, who himself voted for the story to receive the Silver Globe award, considers it a "good, the best of those printed in 1999, [...] and important" text, if not outstanding. According to the writer, the author successfully combined the thread of a "banal love story" with "internet-related details," creating a realistic story in the cyberpunk genre, which he sees as "a pioneering work in Polish SF." He criticized Parowski for neither understanding nor appreciating the culture of the Internet, and for "failing to see the values in the text that most readers and writers have seen, despite being pointed out to him."
Oramus's response was considered the most critical. Oramus admitted that neither he nor Parowski "feel connected to the Internet subculture from which the story originates". He described the story as banal and devoid of literary value ("Lietke's sentences hit the reader on the head like flails, like mauls, it is difficult to finish them in their tedious manner, because boredom is everywhere..."); he also assessed the story as insufficiently fantastic and criticized members of the Polish fandom who voted for the story to receive awards as not having good enough taste.
The reviews in Nowa Fantastyka were controversial with fans. Oramus's review was criticized in depth in the fanzine by Konrad Wagrowski, who found it poorly argued and offensive, especially to younger science fiction fans. Wagrowski although argued, like Dukaj, that the story had been misunderstood by critics who were not interested in and familiar with the Internet culture. The April issue of Nowa Fantastyka printed six letters to the editor about "Critics about CyberJoly Drim", four of which defended the story and one of which criticized it.
Later reviews
The story has received several reviews in the later years. Two of them were critical, with Andrzej Zimniak in Nowa Fantastyka in 2008 finding it to be "literarily mediocre" and undeserving of its awards; while Krzysztof Głuch in in 2011 focused on its prior publication on the Internet and its use of Internet slang which he saw as already dated and gimmicky. Liedtke was widely seen as an outsider to the SF scene, described as such in Zimniak's review.
On the other hand, in 2004, Wojciech Orliński wrote positively about the story in Gazeta Wyborcza, writing that the story "brilliantly reflects" the problem of how for some people the "virtual" world is more interesting than the "real" one. Maria Głowacka, writing in 2013 for , concluded that the controversy and criticism were related to the fact that the author was a woman from the Internet community, while the negative opinions about the text in industry magazines were made "exclusively by male writers-critics", which, according to her, indicates the "closet nature of the Polish science fiction industry". Regarding the charge that the story was insufficiently SF, in 2020 wrote for the culture.pl portal that thanks to elements such as "implants, cyberspaces and virtual realities" the story "passes the "full-fledged cyberpunk" test without any problems". In 2022, Stanisław Krawczyk located the rejection of the story by Parowski and Oramus in a dispute that was going on at the time between them (primarily Parowski) and a group of fans and critics from the Polish science fiction and fantasy fandom, whom Parowski labelled "fans of entertainment fantasy". At around the same time, Parowski himself, in his autobiographical book on the history of that community, mentioned Liedtke's story in the context of his "unwise war on fandom" and admitted that he "missed the real change in audience tastes".
In addition to literary criticism, the story has been subject to scholarly analysis, focusing not on its literary values, but on its themes. analyzed the story from the perspective of feminist literary criticism and the relationship between humans and technology. She focused on the heroine's marginalization of her corporeality and the simultaneous presentation of cyberspace as a space friendly to women. Similarly, in 2021, Przemysław Czapliński stated that the heroine's abandonment of her body in favor of an online existence "constituted a form of rebellion against the patriarchal appropriation of the body that dominates in real life".
References
External links
The story on the author's page
1998 short stories
Cyberpunk short stories
Cyberspace
Polish science fiction works
Polish-language literature
Works set in Poland
Polish speculative fiction short stories
Short stories set in Poland | CyberJoly Drim | [
"Technology"
] | 1,716 | [
"Information technology",
"Cyberspace"
] |
77,508,314 | https://en.wikipedia.org/wiki/Severin%20Hallauer | Severin Hallauer (born 1996 in Basel, Switzerland) is a Swiss visual artist, actor, and model living in Mexico City and Zurich.
Biography
Hallauer was born in 1996 in Basel and grew up in the rural Northwestern Switzerland. From 2013 to 2014, he completed the preparatory course at the Schule für Gestaltung Basel. In 2014, Hallauer was arrested by the police during an art action at Art Basel on the Messeplatz. The incident attracted attention in the international art world and made headlines.
After completing the preparatory course, Hallauer acted as an actor at the Theater Basel. In 2015, Hallauer made headlines with an art action in which he appeared naked and painted white for the mandatory conscription of the Swiss Army. From 2015 to 2019, Hallauer completed the Bachelor of Fine Arts at the Zurich University of the Arts and in 2018 in the Jankowski class of the State Academy of Fine Arts Stuttgart. In 2019, Hallauer made headlines again during the Sofia Art Week in Bulgaria with a public art action that went viral. In this art action, he appeared naked on monuments, including the famous lion statues in front of the Palace of Justice in Sofia.
Severin Hallauer received the 2021 Award for Visual Arts from the Canton of Solothurn. Also in 2021, Hallauer emigrated to Mexico, where he has since lived and worked in Mexico City alongside his second residence in Zurich.
Hallauer expresses himself in compelling performances and works in various media on philosophical and socio-political issues. His oeuvre includes performance, installation, video, sculpture, painting, and photography.
In addition to his work as a visual artist, Severin Hallauer also appears as an actor and model. Recently, Hallauer was seen in the award-winning short film Heart Fruit by Kim Allamand at the Locarno Film Festival and other international festivals. In 2018, Hallauer performed in The Divine Comedy by Rirkrit Tiravanija at the Fondation Beyeler.
Quotes
Criticism
Severin Hallauer's work polarizes and receives both recognition and critical feedback. Some critics praise his work as a bold and profound engagement with social and philosophical issues. Others see his actions as excessive self-promotion aimed at scandals. In 2024, Hallauer responded to this criticism in an interview, saying, "Scandal plays no role in my work. I don't sit in my studio imagining how I can provoke my fellow humans. It's an uncompromising honesty that I demand from my art. […] If viewers feel provoked by my art, it says more about them than about me and my art."
Awards
2021: Visual Arts Award of the Canton of Solothurn
Exhibitions (selection)
2018: Academiae – Youth Art Biennial, Franzensfeste
2019: Das Unbegreifliche Schweigen Der Welt, Gasträume 2019 | Zurich
2019: what do you want me to believe in?, Æther Art Space, Sofia Art Week, Sofia
2021: Infinitum You, Allda, Zurich
2021: InRelation, I see you now, Schlumpf, Riehen
2021: Loving Switzerland, Künstlerhaus S11, Kantonale Förderpreise 2021, Solothurn
2022: entrée&hommage, M54, Basel
2023: Eros Y Ambigüedad, Galeria Luis Adelantado, Mexico City
2023: Eros Y Ambigüedad, Galeria Revuelta, Mexico City
2024: Radical Joy, Riverfront Art Gallery, Yonkers Public Library, Yonkers, New York
Performances (selection)
2015: L‘individue neutre, Rekrutierungszentrum, Windisch
2016: In between the complexes, ACT Performance Festival 16, Théâtre de L‘Usine, Geneva
2017: J’ai tué mon ami, ACT Performance Festival 17, Merian Gärten, Basel
2017: reflection, Kunstfreitag, Kunstverein, Friedrichshafen
2019: duality, Sommerfest, Kunsthalle Bern
2019: nude and monument, Sofia Art Week, Æther Art Space Sofia
2019: redshift, Kunstraum Aarau
2020: I just want to be (in)visible, Queer Sex Health Festival, Kosmos, Zurich
2020: Surfaces, Bagno Popolare, Baden
2020: Unos Pro Omnibus Omnes Pro Oeconomia, Paradeplatz, Zurich
Filmography (selection)
2017: Carvel – Fall For Me (Music video)
2017: Len Sander – Woman On The Run (Music video)
2017: Space Tourists – Dagger Child (Music video)
2018: Enoxaiar (Short film)
2019: nothing is quite as it seems (Fashion film)
2019: The Burden Remains – Fluid (Music film)
2021: Heart Fruit (Short film)
2021: Livia Rita – Muscle of Freedom (Music video)
Theater (selection)
2015: Hamlet, Theater Basel
2016: Médée, Opera, Theater Basel
2017: Es war ein mal ein Einsam, Theater in allen Räumen 17, Theater der Künste, Zurich
2018: Lachsfrühstück für 1 Person, Theater in allen Räumen 18, Theater der Künste, Zurich
2019: I say I shoot you. you are dead, Gruppe CIS, Theater Rampe, Stuttgart, Sophiensääle, Berlin
2020: Abschied, Festival der Liebe VI, Kulturhaus Helferei, Zurich
References
External links
Website of the artist
Mutual Art on Severin Hallauer
up&coming on Severin Hallauer
IMDb on Severin Hallauer
SwissFilms on Severin Hallauer
MUBI on Severin Hallauer
1996 births
Living people
21st-century Swiss male artists
Multimedia artists
Swiss contemporary artists
Swiss installation artists
Swiss male actors
Swiss male models
Swiss emigrants to Mexico
Swiss performance artists
Swiss video artists | Severin Hallauer | [
"Technology"
] | 1,215 | [
"Multimedia",
"Multimedia artists"
] |
77,509,119 | https://en.wikipedia.org/wiki/NGC%205235 | NGC 5235 is an intermediate spiral galaxy in the constellation of Virgo. Its velocity with respect to the cosmic microwave background is 6871 ± 23 km/s, which corresponds to a Hubble distance of 101.34 ± 7.10 Mpc (∼330 million light-years). It was discovered by German-British astronomer William Herschel on 13 April 1784.
In the same area of the sky are the galaxies NGC 5210, NGC 5224, and NGC 5239, among others.
One supernova has been observed in NGC 5235: SN 2024grb (type Ia, mag. 18.333) was discovered by ATLAS on 16 April 2024.
See also
List of NGC objects (5001–6000)
References
External links
5235
47984
08582
13335+0650
Virgo (constellation)
17840413
Discoveries by William Herschel
+01-35-012
Barred spiral galaxies | NGC 5235 | [
"Astronomy"
] | 193 | [
"Virgo (constellation)",
"Constellations"
] |
77,509,282 | https://en.wikipedia.org/wiki/NGC%207769 | NGC 7769 is an unbarred spiral galaxy in the constellation of Pegasus. Its velocity with respect to the cosmic microwave background is 3855 ± 25 km/s, which corresponds to a Hubble distance of 56.85 ± 4 Mpc (∼185 million light-years). It was discovered by German-British astronomer William Herschel on 18 September 1784.
The galaxies NGC 7769, together with NGC 7770 and NGC 7771, are listed together as Holm 820 in Erik Holmberg's A Study of Double and Multiple Galaxies Together with Inquiries into some General Metagalactic Problems, published in 1937. NGC 7769 also is listed as part of the five-member NGC 7771 Group (also known as LGG 483), which contains the 3 galaxies from Holm 820, NGC 7786, and UGC 12828.
NGC 7769 is a LINER galaxy, i.e. it has a type of nucleus that is defined by its spectral line emission which has weakly ionized or neutral atoms, while the spectral line emission from strongly ionized atoms is relatively weak.
Supernovae
Three supernovae have been observed in NGC 7769:
SN 2019iex (type II, mag. 17.6) was discovered by the Searches After Gravitational-waves using ARizona Observatories (SAGUARO) project on 26 June 2019.
SN 2022mxv (type II, mag. 18.249) was discovered by ATLAS on 18 June 2022.
SN 2024grb (type II, mag. 18.2) was discovered by ATLAS on 16 April 2024.
See also
List of NGC objects (7001–7840)
References
External links
7769
072615
12808
23485+1952
Pegasus (constellation)
17840918
Discoveries by William Herschel
+03-60-030
Unbarred spiral galaxies
LINER galaxies
Markarian galaxies | NGC 7769 | [
"Astronomy"
] | 394 | [
"Pegasus (constellation)",
"Constellations"
] |
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