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41,351,898 | https://en.wikipedia.org/wiki/Subset%20simulation | Subset simulation is a method used in reliability engineering to compute small (i.e., rare event) failure probabilities encountered in engineering systems. The basic idea is to express a small failure probability as a product of larger conditional probabilities by introducing intermediate failure events. This conceptually converts the original rare-event problem into a series of frequent-event problems that are easier to solve. In the actual implementation, samples conditional on intermediate failure events are adaptively generated to gradually populate from the frequent to rare event region. These 'conditional samples' provide information for estimating the complementary cumulative distribution function (CCDF) of the quantity of interest (that governs failure), covering the high as well as the low probability regions. They can also be used for investigating the cause and consequence of failure events. The generation of conditional samples is not trivial but can be performed efficiently using Markov chain Monte Carlo (MCMC).
Subset simulation takes the relationship between the (input) random variables and the (output) response quantity of interest as a 'black box'. This can be attractive for complex systems where it is difficult to use other variance reduction or rare-event sampling techniques that require prior information about the system behaviour. For problems where it is possible to incorporate prior information into the reliability algorithm, it is often more efficient to use other variance reduction techniques such as importance sampling. It has been shown that subset simulation is more efficient than traditional Monte Carlo simulation, but less efficient than line sampling, when applied to a fracture mechanics test problem.
Basic idea
Let X be a vector of random variables and Y = h(X) be a scalar (output) response quantity of interest for which the failure probability is to be determined. Each evaluation of h(·) is expensive and so it should be avoided if possible. Using direct Monte Carlo methods one can generate i.i.d. (independent and identically distributed) samples of X and then estimate P(F) simply as the fraction of samples with Y > b. However this is not efficient when P(F) is small because most samples will not fail (i.e., with Y ≤ b) and in many cases an estimate of 0 results. As a rule of thumb for small P(F) one requires 10 failed samples to estimate P(F) with a coefficient of variation of 30% (a moderate requirement). For example, 10000 i.i.d. samples, and hence evaluations of h(·), would be required for such an estimate if P(F) = 0.001.
Subset simulation attempts to convert a rare event problem into more frequent ones. Let be an increasing sequence of intermediate threshold levels. From the basic property of conditional probability,
The 'raw idea' of subset simulation is to estimate P(F) by estimating and the conditional probabilities for , anticipating efficiency gain when these probabilities are not small. To implement this idea there are two basic issues:
Estimating the conditional probabilities by means of simulation requires the efficient generation of samples of X conditional on the intermediate failure events, i.e., the conditional samples. This is generally non-trivial.
The intermediate threshold levels should be chosen so that the intermediate probabilities are not too small (otherwise ending up with rare event problem again) but not too large (otherwise requiring too many levels to reach the target event). However, this requires information of the CCDF, which is the target to be estimated.
In the standard algorithm of subset simulation the first issue is resolved by using Markov chain Monte Carlo. More generic and flexible version of the simulation algorithms not based on Markov chain Monte Carlo have been recently developed. The second issue is resolved by choosing the intermediate threshold levels {bi} adaptively using samples from the last simulation level. As a result, subset simulation in fact produces a set of estimates for b that corresponds to different fixed values of p = P(Y > b), rather than estimates of probabilities for fixed threshold values.
There are a number of variations of subset simulation used in different contexts in applied probability and stochastic operations research
For example, in some variations the simulation effort to estimate
each conditional probability P(Y > bi | Y > bi−1) (i = 2, ..., m) may not be fixed prior to the simulation, but may be random, similar to the splitting method in rare-event probability estimation.
These versions of subset simulation can also be used to approximately sample from the distribution of X given the failure of the system (that is, conditional on the event ). In that case, the relative variance of the (random) number of particles in the final level can be used to bound the sampling error as measured by the total variation distance of probability measures.
See also
Rare event sampling
Curse of dimensionality
Line sampling
Notes
See Au & Wang for an introductory coverage of subset simulation and its application to engineering risk analysis.
Schuëller & Pradlwarter reports the performance of subset simulation (and other variance-reduction techniques) in a set of stochastic mechanics benchmark problems.
Chapter 4 of Phoon discusses the application of subset simulation (and other Monte Carlo methods) to geotechnical engineering problems.
Zio & Pedroni discusses the application of subset simulation (and other methods) to a problem in nuclear engineering.
References
Reliability analysis
Variance reduction | Subset simulation | [
"Engineering"
] | 1,092 | [
"Reliability analysis",
"Reliability engineering"
] |
41,352,219 | https://en.wikipedia.org/wiki/Mobile%20virtual%20network%20enabler | A mobile virtual network enabler (MVNE) is a company that provides network infrastructure and related services, such as business support system, and operation support system to a mobile virtual network operator (MVNO). This enables MVNOs to offer services to their own customers with their own brands. The MVNE does not have a relationship with consumers, but rather is a provider of network enablement platforms and services.
MVNEs specialize in planning, implementation, and management of mobile services. Typically this includes SIM provisioning and configuration, customer billing, customer relationship management, and value-added service platforms. In effect, they enable an MVNO to outsource both the initial integration with the MNO, and the ongoing business and technical operations management. A related type of company is a mobile virtual network aggregator (MVNA). MVNE is a telecom solution, whereas MVNA is a business model which includes wholesale of an operator's airtime and routing of traffic over the MVNE's own switches.
The benefits of using an MVNE include a reduction in the upfront capital expenses of an MVNO due to reduced operational expenses via outsourcing management of business and technical operations.
Using an MVNE may not be appropriate for all MVNOs. The considerations for this decision are manifold; however, some of the key reasons for an MVNO to not use an MVNE would be:
The MVNO is large enough to achieve volume efficiency when going direct to the host operator (usually several hundred thousand subscribers).
The brand and distribution channels are sufficiently strong to negotiate a joint-venture or direct relationship and obtain better margins.
The MVNO has access to existing telecom infrastructure, for example switches, international capacity, fixed infrastructure, and billing platforms.
See also
Business Process Framework (eTOM)
Mobile network operator
Mobile virtual network operator
Operations, administration and management (OAM)
References
Business software
Telecommunications systems
Mobile technology
Telecommunications infrastructure | Mobile virtual network enabler | [
"Technology"
] | 387 | [
"Telecommunications systems",
"nan"
] |
41,352,383 | https://en.wikipedia.org/wiki/Maximiscin | Maximiscin is a polyketide-shikimate chemical compound isolated from Tolypocladium that shows tumor growth suppression in an animal model. The discovery of maximiscin was the result of a citizen scientist crowdsourcing project by the University of Oklahoma. The soil sample which yielded maximiscin was sent by a woman from Salcha, Alaska.
References
Methyl esters
Lactams
Polyketides
Cyclohexenes | Maximiscin | [
"Chemistry"
] | 93 | [
"Biomolecules by chemical classification",
"Natural products",
"Polyketides"
] |
41,352,442 | https://en.wikipedia.org/wiki/Antiamoebin | Antiamoebin is an anti-microbial/protozoan polypeptide of fungal origin.
References
Polypeptide antibiotics | Antiamoebin | [
"Chemistry"
] | 30 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
41,352,921 | https://en.wikipedia.org/wiki/Washington%20University%20Sentence%20Completion%20Test | The Washington University Sentence Completion Test (WUSCT) is a sentence completion test created by Jane Loevinger, which measures ego development along Loevinger's stages of ego development. The WUSCT is a projective test; a type of psychometric test designed to measure psychic phenomenon by capturing a subject's psychological projection and measuring it in a quantifiable manner. The test has been characterized as a good test for clinical use as it can measure across distinct psychopathologies and help in choosing treatment modalities; to this end, it is used by many clinical psychologists and psychiatrists.
History
Stated simply, ego development refers to the observation that people do not remain psychologically static throughout their lives; rather, they undergo a long process of internal evolution. As such, the concept itself is ancient in origin and has received some form of treatment in almost all systems of philosophy and all schools of psychology.
Loevinger conceived of an ego development system that would closely resemble moral development but be both broader in scope and utilize empirical methods of study. Loevinger started by creating an objective test of mother's attitudes to problems in family life, which she christened the Family Problems Scale. This first test did not yield the expected results, but Loevinger noticed a strong similarity between the Authoritarian Family Ideology and the concept of authoritarian personality being developed at UC Berkeley in the early 1960s. Loevinger noticed that the women who scored at the most extreme ends of the authoritarian scale also tended to be the most immature, endorsing items like "A mother should be her daughter's best friend", while simultaneously endorsing punitive behavior. Additionally, she noted that a liberal, non-authoritarian personality was not the opposite of a high authoritarian personality. Rather, anomie, a disorganized and detached social style was the opposite of the high authoritarian, exhibiting a curvilinear relationship. Loevinger theorized that this was because the Authoritarian Family Ideology scale was not measuring just authoritarianism but some broader concept which weighed heavily upon all the other constructs she measured. By combining this theoretical framework with Sullivan and Grant's interpersonal maturity continuum, the concept of ego development was born.
While the WUSCT is a projective test, Loevinger wanted it to be as objective as possible and developed several unique rules regarding scoring. For example, every response must be scored even if it is incomplete or fragmentary. Loevinger found the WUSCT to be more sensitive than the previous Family Problems Scale and adopted it as her main measure of ego development, publishing the WUSCT in 1979.
Background
The test is ultimately grounded in Loevinger's vision of ego development and its use carries a strong theoretical component. Loevinger chose to use a projective test, relying on the principle that item stem responses are a reflection of internal, conscious and unconscious processes. Loevinger crystallizes the definition of ego as a stable self-system which is at once the fundamental frame of reference and the master trait from which all other personality traits emanate, much like the psychometric construct of intelligence, the g factor. The ego maintains its coherence by acting as a filter between itself and the world, allowing in only that which reinforces the system and rejecting that which might destabilize it. Thus, the WUSCT can identify stable configurations of the ego and place them in quasi-hierarchical stages.
Procedure
The WUSCT is a pencil-and-paper test (though in recent years has been administered by computer) which consists of 36 items that take the form of "stems" which the subject may answer in any way they wish. The stems take the form of incomplete sentences; for example, one item states simply "When people are helpless" with instructions prompting the test-taker to complete the rest.
The clinician or researcher should be present in the room with the test-taker to prevent the subject from asking others how they should answer the question. Additionally, the administrator should only answer questions regarding the test in a non-committal fashion, reiterating that the subject may complete the stem however he or she wishes. This may even include fragmentary or non-responses, which Loevinger asserts are still of importance and must be rated as any other response.
Scoring
Unlike many other projective tests the SCT has a number of strong, empirically derived rules that drive a rater's scoring method. These rules help the WUSCT to have a higher inter-rater reliability and also increase the overall reliability of the test.
If the test was taken on pen-and-paper, the responses should be typed up and any identifying information is deleted to protect the subject's privacy and to prevent identifying information from coloring the rater's scores. The rater then generates scores based on Loevinger's stages of ego development for each item. A total protocol rating (TPR) is then generated for the test, there are several algorithms for a generating a TPR (such as simply taking the mode of the distribution of item ratings). However, the manual suggests generating an impressionistic level (the rater's impression of what kind of person answered the items) and comparing this to a cumulative frequency distribution (ogive). If the two ratings match, this TPR is assigned to the case, if they do not match the manual provides a number of rules for tie-breaking between the impressionistic rating and the ogive rule.
See also
References
Developmental psychology
Developmental stage theories
Psychological tests and scales | Washington University Sentence Completion Test | [
"Biology"
] | 1,130 | [
"Behavioural sciences",
"Behavior",
"Developmental psychology"
] |
41,353,264 | https://en.wikipedia.org/wiki/American%20College%20of%20Neuropsychopharmacology | Founded in 1961, the American College of Neuropsychopharmacology (ACNP) is a professional organization of leading brain and behavior scientists. The principal functions of the College are research and education. Their goals in research are to offer investigators an opportunity for cross-disciplinary communication and to promote the application of various scientific disciplines to the study of the brain's effect on behavior, with a focus on mental illness of all forms. Their educational goals are to encourage young scientists to enter research careers in neuropsychopharmacology and to develop and provide accurate information about behavioral disorders and their pharmacological treatment.
Organization
The College is an honorific society. Members are selected primarily on the basis of their original research contributions to the broad field of neuroscience. The membership of the College is drawn from scientists in multiple fields including behavioral pharmacology, neuroimaging, chronobiology, clinical psychopharmacology, epidemiology, genetics, molecular biology, neurochemistry, neuroendocrinology, neuroimmunology, neurology, neurophysiology, psychiatry, and psychology.
Annual meeting
The annual meeting of the College is a closed meeting; only the ACNP members and their invited guests may attend. Because of the College's intense concern with, and involvement in, the education and training of tomorrow's brain scientists, the College selects a number of young scientists to be invited to the annual meeting through a competitive process open to all early career researchers. This meeting, a mix of foremost brain and behavior research world-wide, is designed to encourage dialogue, discussion, and synergy by those attending.
Awards
The ACNP offers the following awards.
Julius Axelrod Mentorship Award
Daniel H. Efron Research Award
Joel Elkes Research Award
Barbara Fish Memorial Award
Paul Hoch Distinguished Service Award
Eva King Killam Research Award
Dolores Shockley Diversity and Inclusion Advancement Award
Media Award
Public Service Award
Women's Advocacy Award
Publication
The Springer-Nature Publishing Group journals Neuropsychopharmacology and NPP-Digital Psychiatry and Neuroscience are their official publications. Neuropsychopharmacology was first published in 1987 and NPP-Digital Psychiatry and Neuroscience is an Open Access journal that started in 2023.
References
See also
European Brain Council
European College of Neuropsychopharmacology
Neuropsychopharmacology (journal)
Neuropharmacology
Neuroscience organizations
Organizations based in Tennessee
Organizations established in 1961
Research organizations in the United States | American College of Neuropsychopharmacology | [
"Chemistry"
] | 507 | [
"Pharmacology",
"Neuropharmacology"
] |
41,353,319 | https://en.wikipedia.org/wiki/Kepler-23 | Kepler-23 is a G-type main-sequence star about away in the northern constellation of Cygnus, the swan. With an apparent visual magnitude of 13.5, it is too faint to be seen with the naked eye. This star is similar in mass and temperature to the Sun, but is larger and more luminous. Kepler-23 is orbited by three known exoplanets.
Planetary system
Three transiting exoplanets orbit this star, discovered using the Kepler space telescope. Two planets, Kepler-23b and Kepler-23c, were discovered in 2011 and were confirmed in 2012. A third planet, Kepler-23d, was confirmed in 2014 as part of a study validating hundreds of Kepler candidates. All three planets are between Earth and Neptune in size (sub-Neptunes), and their masses have been measured via transit-timing variations, showing that they have lower densities than Earth.
References
Cygnus (constellation)
G-type main-sequence stars
168
Planetary transit variables
Planetary systems with three confirmed planets
J19365254+4928452 | Kepler-23 | [
"Astronomy"
] | 224 | [
"Cygnus (constellation)",
"Constellations"
] |
41,355,223 | https://en.wikipedia.org/wiki/A2261-BCG | A2261-BCG (short for Abell 2261 Brightest Cluster Galaxy) is a huge elliptical galaxy in the cluster Abell 2261. One of the largest galaxies known, A2261-BCG is estimated to have a diameter of a million light-years, some 10 times larger than the Milky Way. It is the brightest and the most massive galaxy in the cluster, and has one of the largest galactic cores ever observed, spanning more than 10,000 light-years. Yet, unusually, its center does not contain a supermassive black hole.
The cD elliptical galaxy, located at least 3 billion light-years from Earth, is also well known as a radio source. Its core is highly populated by a dense number of old stars, but is mysteriously diffuse, giving it a large core. On September 10, 2012, using Hubble Space Telescope's Wide Field Camera 3, scientists realized there was no supermassive black hole present in its center.
References
Elliptical galaxies
Hercules (constellation)
1981854 | A2261-BCG | [
"Astronomy"
] | 209 | [
"Hercules (constellation)",
"Constellations"
] |
41,355,731 | https://en.wikipedia.org/wiki/The%20Game%20of%20Logic | The Game of Logic is a book, published in 1886, written by the English mathematician Charles Lutwidge Dodgson (1832–1898), better known under his literary pseudonym Lewis Carroll.
In addition to his well-known children's literature, Dodgson/Carroll was an academic mathematician who worked in mathematical logic. The book describes, in an informal and playful style, the use of a board game to represent logical propositions and inferences. Dodgson/Carroll incorporated the game into a longer and more formal introductory logic textbook titled Symbolic Logic, published in 1897. The books are sometimes reprinted in a single volume.
The book aims to teach players the fundamentals of logic by asking players to use coins on a board. The proposition used in this context is: "Some fresh cakes are sweet." The game world is divided into four quadrants. It is to be played with five gray coins and four red coins. A red coin symbolizes one or more cakes being present in an area while a gray coin symbolizes the absence of the cake(s). Each quadrant represents a variation of the original proposition. The cakes are fresh and sweet within the northwest quadrant. They are fresh but not sweet in the northeast. They are neither fresh nor sweet in the southeast. They are not fresh but are sweet in the southwest.
The four quadrants are further divided into two subclasses: cakes that are eatable and those that are non-eatable. This subdivision allows players to understand more complex propositions and syllogisms.
The second half of the book introduces players to a 2x2x2 diagram. This allows for players to solve problems involving three propositions at the same time.
The book is divided into several chapters. The first portion, "To My Childhood-Friend" is as an introduction from the author to his readers. This is followed by a preface chapter. Chapter 1 is divided into three parts. In the first part, the author describes the three different types of propositions that will be used. The second part is an outlook on the "Universe of Things" and syllogisms. The third part of the chapter explains the logic to be used and the associated fallacies. This marks the end of the first chapter. The second chapter presents various questions for readers to answer. These questions are then answered and explained by the author in the third chapter. The last and fourth chapter contains various logic games.
See also
Logic puzzle
Carroll diagram
References
External links
Scanned copy at archive.org
Entry at gutenberg.org
Online resource including demonstration tool for The Game of Logic
1886 non-fiction books
Board games introduced in the 1880s
Books about board games
British board games
Educational board games
Logic
Recreational mathematics
Works by Lewis Carroll | The Game of Logic | [
"Mathematics"
] | 555 | [
"Recreational mathematics"
] |
41,356,379 | https://en.wikipedia.org/wiki/Europa%20Clipper | Europa Clipper (previously known as Europa Multiple Flyby Mission) is a space probe developed by NASA to study Europa, a Galilean moon of Jupiter. It was launched on October 14, 2024. The spacecraft will use gravity assists from Mars on March 1, 2025, and Earth on December 3, 2026, before arriving at Europa in April 2030. The spacecraft will then perform a series of flybys of Europa while in orbit around Jupiter.
Europa Clipper is designed to follow up on evidence for a subsurface ocean underneath Europa's ice crust, found using the Galileo spacecraft which orbited Jupiter from 1995 to 2003. Plans to send a spacecraft to Europa were initially conceived with projects such as Europa Orbiter and Jupiter Icy Moons Orbiter, in which a spacecraft would be inserted into orbit around Europa. However, due to the adverse effects of radiation from the magnetosphere of Jupiter in Europa orbit, it was decided that it would be safer to insert a spacecraft into an elliptical orbit around Jupiter and make 49 close flybys of the moon instead. The Europa Clipper spacecraft is larger than any other used for previous NASA planetary missions.
The spacecraft will analyze the presence of an induced magnetic field around Europa, and attempt to detect plumes of water ejecta from a subsurface ocean; in addition to various other tests.
The mission's name is a reference to the lightweight and fast clipper ships of the 19th century that routinely plied trade routes, since the spacecraft will pass by Europa at a rapid cadence, as frequently as every two weeks. The mission patch, which features a depiction of a sail ship, references the moniker.
Europa Clipper complements the ESA's Jupiter Icy Moons Explorer, launched in 2023, which will attempt to fly past Europa twice and Callisto multiple times before moving into orbit around Ganymede.
History
Early proposals and Galileo discoveries
In 1997, a Europa Orbiter mission was proposed by a team for NASA's Discovery Program but was not selected. NASA's JPL announced one month after the selection of Discovery proposals that a NASA Europa orbiter mission would be conducted. JPL then invited the Discovery proposal team to be the Mission Review Committee (MRC).
At the same time as the proposal of the Discovery-class Europa Orbiter, the robotic Galileo spacecraft was already orbiting Jupiter. From December 8, 1995, to December 7, 1997, Galileo conducted the primary mission after entering the orbit of Jupiter. On that final date, the Galileo orbiter commenced an extended mission known as the Galileo Europa Mission (GEM), which ran until December 31, 1999. This was a low-cost mission extension with a budget of only US$30 million. The smaller team of about 40–50 people (compared with the primary mission's 200-person team from 1995 to 1997) did not have the resources to deal with problems, but when they arose, it was able to temporarily recall former team members (called "tiger teams") for intensive efforts to solve them. The spacecraft made several flybys of Europa (8), Callisto (4) and Io (2). On each flyby of the three moons it encountered, the spacecraft collected only two days' worth of data instead of the seven it had collected during the primary mission. During GEM's eight flybys of Europa, it ranged from , in two years.
Europa has been identified as one of the locations in the Solar System that could possibly harbor microbial extraterrestrial life. Immediately following the Galileo spacecraft's discoveries and the independent Discovery program proposal for a Europa orbiter, JPL conducted preliminary mission studies that envisioned a capable spacecraft such as the Jupiter Icy Moons Orbiter (a US$16 billion mission concept), the Jupiter Europa Orbiter (a US$4.3 billion concept), another orbiter (US$2 billion concept), and a multi-flyby spacecraft: Europa Clipper.
A mission to Europa was recommended by the National Research Council in 2013. The approximate cost estimate rose from US$2 billion in 2013 to US$4.25 billion in 2020. The mission is a joint project between the Johns Hopkins University's Applied Physics Laboratory (APL), and the Jet Propulsion Laboratory (JPL).
Funding put forward
In March 2013, US$75 million was authorized to expand on the formulation of mission activities, mature the proposed science goals, and fund preliminary instrument development, as suggested in 2011 by the Planetary Science Decadal Survey. In May 2014, a House bill substantially increased the Europa Clipper (referred to as Europa Multiple Flyby Mission) funding budget for the 2014 fiscal year from US$15 million to US$100 million to be applied to pre-formulation work. Following the 2014 election cycle, bipartisan support was pledged to continue funding for the Europa Multiple Flyby Mission project. The executive branch also granted US$30 million for preliminary studies.
Formulation
In April 2015, NASA invited the ESA to submit concepts for an additional probe to fly together with the Europa Clipper spacecraft, with a mass limit of 250 kg. It could be a simple probe, an impactor, or a lander. An internal assessment at ESA considered whether there was interest and funds available, opening a collaboration scheme similar to the very successful Cassini–Huygens approach.
In May 2015, NASA chose nine instruments that would fly on board the orbiter, budgeted to cost about US$110 million over the next three years. In June 2015, NASA approved the mission concept, allowing the orbiter to move to its formulation stage. In January 2016, NASA approved the addition of a lander, but this was canceled in 2017 because it was deemed too risky. In May 2016, the Ocean Worlds Exploration Program was approved, of which the Europa mission is part.
In February 2017, the mission moved from Phase A to Phase B (the preliminary design phase). On July 18, 2017, the House Space Subcommittee held hearings on the Europa Clipper as a scheduled Large Strategic Science Missions class, and to discuss a possible follow up mission simply known as the Europa Lander. Phase B continued into 2019. In addition, subsystem vendors were selected, as well as prototype hardware elements for the science instruments. Spacecraft sub-assemblies were built and tested as well.
Fabrication and assembly
On August 19, 2019, the Europa Clipper proceeded to Phase C: final design and fabrication.
On March 3, 2022, the spacecraft moved on to Phase D: assembly, testing, and launch. On June 7, 2022, the main body of the spacecraft was completed. By August 2022, the high-gain antenna had completed its major testing campaigns.
By January 30, 2024, all of the science instruments were added to the spacecraft. The reason the instrument's electronics were aboard the spacecraft is because, while its antennas were added to the spacecraft's solar arrays at Kennedy Space Center later in the year, the former were not. In March 2024, it was reported that the spacecraft underwent successful testing and was on track for launch later in the year. In May 2024, the spacecraft arrived at Kennedy Space Center for final launch preparations. In September 2024, final pre-launch review was successfully completed, clearing the way for launch. In early October 2024, due to the incoming Hurricane Milton, the spacecraft was placed in secure storage for safekeeping until the hurricane passed.
Launch
In July 2024, the spacecraft faced concerns of delay and missing the launch window because of a discovery in June 2024 that its components were not as radiation-hardened as previously believed. However, over the summer, intensive re-testing of the transistor components in question found that they would likely be annealed enough to 'self-heal'. In September 2024, Europa Clipper was approved for a launch window opening on October 10, 2024; however, on October 6, 2024, NASA announced that it would be standing down from the October 10 launch due to Hurricane Milton. Europa Clipper was finally launched on October 14, 2024.
End of mission planning
The probe is scheduled to be crashed into Jupiter, Ganymede, or Callisto, to prevent it from crashing into Europa. In June 2022, lead project scientist Robert Pappalardo revealed that mission planners for Europa Clipper were considering disposing of the probe by crashing it into the surface of Ganymede in case an extended mission was not approved early in the main science phase. He noted that an impact would help the ESA's JUICE mission collect more information about Ganymede's surface chemistry. In a 2024 paper, Pappalardo said the mission would last four years in Jupiter orbit, and that the disposal was targeted for September 3, 2034, if NASA did not approve a mission extension.
Objectives
The goals of Europa Clipper are to explore Europa, investigate its habitability and aid in the selection of a landing site for the proposed Europa Lander. This exploration is focused on understanding the three main requirements for life: liquid water, chemistry, and energy. Specifically, the objectives are to study:
Ice shell and ocean: Confirm the existence and characterize the nature of water within or beneath the ice, and study processes of surface-ice-ocean exchange.
Composition: Distribution and chemistry of key compounds and the links to ocean composition.
Geology: Characteristics and formation of surface features, including sites of recent or current activity.
The spacecraft carries scientific instruments which will be used to analyze the potential presence of geothermal activity and the Moon's induced magnetic field; which in turn will provide an indication to the presence of saline rich subsurface ocean(s).
Strategy
Because Europa lies well within the harsh radiation fields surrounding Jupiter, even a radiation-hardened spacecraft in near orbit would be functional for just a few months. Most instruments can gather data far faster than the communications system can transmit it to Earth due to the limited number of antennas available on Earth to receive the scientific data. Therefore, another key limiting factor on science for a Europa orbiter is the time available to return data to Earth. In contrast, the amount of time during which the instruments can make close-up observations is less important.
Studies by scientists from the Jet Propulsion Laboratory show that by performing several flybys with many months to return data, the Europa Clipper concept will enable a US$2 billion mission to conduct the most crucial measurements of the canceled US$4.3 billion Jupiter Europa Orbiter concept. Between each of the flybys, the spacecraft will have seven to ten days to transmit data stored during each brief encounter. That will let the spacecraft have up to a year of time to transmit its data compared to just 30 days for an orbiter. The result will be almost three times as much data returned to Earth, while reducing exposure to radiation. Europa Clipper will not orbit Europa, but will instead orbit Jupiter and conduct 44 flybys of Europa, each at altitudes ranging from 25 km to 2,700 km (16 mi to 1,678 mi) during its 3.5-year mission. A key feature of the mission concept is that Europa Clipper would use gravity assists from Europa, Ganymede and Callisto to change its trajectory, allowing the spacecraft to return to a different close approach point with each flyby. Each flyby would cover a different sector of Europa to achieve a medium-quality global topographic survey, including ice thickness. Europa Clipper could conceivably fly by at low altitude through the plumes of water vapor erupting from the moon's ice crust, thus sampling its subsurface ocean without having to land on the surface and drill through the ice.
The spacecraft is expected to receive a total ionizing dose of during the mission. Shielding from Jupiter's harsh radiation belt will be provided by a radiation vault with thick aluminum alloy walls, which enclose the spacecraft electronics. To maximize the effectiveness of this shielding, the electronics are also nested in the core of the spacecraft for additional radiation protection.
Design and construction
This mission is a flight of NASA's Planetary Science Division, designated a Large Strategic Science Mission, and funded under the Planetary Missions Program Office's Solar System Exploration program as its second flight. It is also supported by the new Ocean Worlds Exploration Program.
The spacecraft bus is a 5-meter-long combination of a 150-cm-wide aluminum cylindrical propulsion module and a rectangular box. The electronic components are protected from the intense radiation by a 150-kilogram titanium, zinc and aluminum shielded vault in the box. The spacecraft payload and trajectory are subject to change as the mission design matures.
Power
Both radioisotope thermoelectric generator (RTG) and photovoltaic power sources were assessed to power the orbiter. Although solar power is only 4% as intense at Jupiter as it is in Earth's orbit, powering a Jupiter orbital spacecraft by solar panels was demonstrated by the Juno mission. The alternative to solar panels was a multi-mission radioisotope thermoelectric generator (MMRTG), fueled with plutonium-238. The power source has already been demonstrated in the Mars Science Laboratory (MSL) mission. Five units were available, with one reserved for the Mars 2020 rover mission and another as backup. In September 2013, it was decided that the solar array was the less expensive option to power the spacecraft, and on October 3, 2014, it was announced that solar panels were chosen to power Europa Clipper. The mission's designers determined that solar power was both cheaper than plutonium and practical to use on the spacecraft. Despite the increased weight of solar panels compared to plutonium-powered generators, the vehicle's mass had been projected to still be within acceptable launch limits.
Each panel has a surface area of and produces 150 watts continuously when pointed towards the Sun while orbiting Jupiter. While in Europa's shadow, batteries will enable the spacecraft to continue gathering data. However, ionizing radiation can damage solar panels. The Europa Clipper orbit will pass through Jupiter's intense magnetosphere, which is expected to gradually degrade the solar panels as the mission progresses. The solar panels were provided by Airbus Defence and Space, Netherlands.
Propulsion
The propulsion subsystem was built by NASA's Goddard Space Flight Center in Greenbelt, Maryland. It is part of the Propulsion Module, delivered by Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. It is tall, in diameter and comprises about two-thirds of the spacecraft's main body. The propulsion subsystem carries nearly of monomethyl hydrazine and dinitrogen tetroxide propellant, 50% to 60% of which will be used for the 6 to 8-hour Jupiter orbit insertion burn. The spacecraft has a total of 24 rocket engines rated at 27.5 N (6.2 lbf) thrust for attitude control and propulsion.
Communication
The probe contains multiple antennas, including the high-gain antenna, which has a 3.1-meter (10-foot) diameter. The high-gain antenna operates on X-band frequencies of 7.2 and 8.4 gigahertz, and a Ka-band frequency of 32 gigahertz (12 times that of a typical cell phone).The antennas will be used to research gravity and radio science, allowing researchers to learn more about Europa's gravity It was designed and constructed by a team led by Matt Bray at the Johns Hopkins Applied Physics Laboratory, before being tested at Langley Research Center and Goddard Space Flight Center in the spring and summer of 2022.
Scientific equipment
The Europa Clipper mission is equipped with nine scientific instruments. The nine science instruments for the orbiter, announced in May 2015, have a planned total mass of .
Europa Thermal Emission Imaging System (E-THEMIS)
The Europa Thermal Emission Imaging System will provide high spatial resolution as well as multi-spectral imaging of the surface of Europa in the mid to far infrared bands to help detect heat which would suggest geologically active sites and areas, such as potential vents erupting plumes of water into space.
The principal investigator is Philip Christensen of Arizona State University. This instrument is derived from the Thermal Emission Imaging System (THEMIS) on the 2001 Mars Odyssey orbiter, also developed by Philip Christensen.
Mapping Imaging Spectrometer for Europa (MISE)
The Mapping Imaging Spectrometer for Europa is an imaging near infrared spectrometer to probe the surface composition of Europa, identifying and mapping the distributions of organics (including amino acids and tholins), salts, acid hydrates, water ice phases, and other materials.
The principal investigator is Diana Blaney of Jet Propulsion Laboratory and the instrument was built in collaboration with the Johns Hopkins University Applied Physics Laboratory (APL).
Europa Imaging System (EIS)
The Europa Imaging System consists of visible spectrum cameras to map Europa's surface and study smaller areas in high resolution, as low as per pixel. It consists of two cameras, both of which use 2048x4096 pixel CMOS detectors:
The Wide-angle Camera (WAC) has a field of view of 48° by 24° and a resolution of from a altitude. Optically the WAC uses 8 lens refractive optics with an 8 mm aperture and a 46 mm focal length which give it a f-number of f/5.75. The WAC will obtain stereo imagery swaths throughout the mission.
The Narrow-angle Camera (NAC) has a 2.3° by 1.2° field of view, giving it a resolution of per pixel from a altitude. Optically the NAC uses a Ritchey Chrétien Cassegrain telescope with a 152 mm aperture and a 1000 mm focal length which give it a f-number of f/6.58. The NAC is mounted on a 2-axis gimbal, allowing it to point at specific targets regardless of the main spacecraft's orientation. This will allow for mapping of >95% of Europa's surface at a resolution of ≤ per pixel. For reference, only around 14% of Europa's surface has previously been mapped at a resolution of ≤ per pixel.
The principal investigator is Elizabeth Turtle of the Applied Physics Laboratory.
Europa Ultraviolet Spectrograph (Europa-UVS)
The Europa Ultraviolet Spectrograph instrument will be able to detect small erupting plumes, and will provide valuable data about the composition and dynamics of the moon's exosphere.
The principal investigator is Kurt Retherford of Southwest Research Institute. Retherford was previously a member of the group that discovered plumes erupting from Europa while using the Hubble Space Telescope in the UV spectrum.
Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON)
The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is a dual-frequency ice penetrating radar (9 and 60 MHz) instrument that is designed to sound Europa's ice crust from the near-surface to the ocean, revealing the hidden structure of Europa's ice shell and potential water pockets within. REASON will probe the exosphere, surface and near-surface and the full depth of the ice shell to the ice-ocean interface up to 30 km.
The principal investigator is Donald Blankenship of the University of Texas at Austin. This instrument was built by Jet Propulsion Laboratory.
Europa Clipper Magnetometer (ECM)
The Europa Clipper Magnetometer (ECM) will be used to analyze the magnetic field around Europa. The instrument consists of three flux gates placed along an 8.5m (25ft) boom, which were stowed during launch and deployed afterwards. The magnetic field of Jupiter is thought to induce electric current in a salty ocean beneath Europa’s ice, which in turn leads Europa to produce its own magnetic field, therefore by studying the strength and orientation of Europa's magnetic field over multiple flybys, scientists hope to be able to confirm the existence of Europa's subsurface ocean, as well as characterize the thickness of its icy crust and estimate the water's depth and salinity.
The instrument team leader is Margaret Kivelson, University of Michigan.
ECM replaced the proposed Interior Characterization of Europa using Magnetometry (ICEMAG) instrument, which was canceled due to cost overruns. ECM is a simpler and cheaper magnetometer than ICEMAG would have been.
Plasma Instrument for Magnetic Sounding (PIMS)
The Plasma Instrument for Magnetic Sounding (PIMS) measures the plasma surrounding Europa to characterize the magnetic fields generated by plasma currents. These plasma currents mask the magnetic induction response of Europa's subsurface ocean. In conjunction with a magnetometer, it is key to determining Europa's ice shell thickness, ocean depth, and salinity. PIMS will also probe the mechanisms responsible for weathering and releasing material from Europa's surface into the atmosphere and ionosphere and understanding how Europa influences its local space environment and Jupiter's magnetosphere.
The principal investigator is Joseph Westlake of the Applied Physics Laboratory.
Mass Spectrometer for Planetary Exploration (MASPEX)
The Mass Spectrometer for Planetary Exploration (MASPEX) will determine the composition of the surface and subsurface ocean by measuring Europa's extremely tenuous atmosphere and any surface materials ejected into space.
Jack Waite, who led development of MASPEX, was also Science Team Lead of the Ion and Neutral Mass Spectrometer (INMS) on the Cassini spacecraft. The principal investigator is Jim Burch of Southwest Research Institute, who was previously the leader of the Magnetospheric Multiscale Mission.
Surface Dust Analyzer (SUDA)
The SUrface Dust Analyzer (SUDA) is a mass spectrometer that will measure the composition of small solid particles ejected from Europa, providing the opportunity to directly sample the surface and potential plumes on low-altitude flybys. The instrument is capable of identifying traces of organic and inorganic compounds in the ice of ejecta, and is sensitive enough to detect signatures of life even if the sample contains less than a single bacterial cell in a collected ice grain.
The principal investigator is Sascha Kempf of the University of Colorado Boulder.
Gravity & Radio Science
Although it was designed primarily for communications, the high-gain radio antenna will be used to perform additional radio observations and investigate Europa's gravitational field, acting as a radio science subsystem. Measuring the Doppler shift in the radio signals between the spacecraft and Earth will allow the spacecraft's motion to be determined in detail. As the spacecraft performs each of its 45 Europa flybys, its trajectory will be altered by the moon's gravitational field. The Doppler data will be used to determine the higher order coefficients of that gravity field, to determine the moon's interior structure, and to examine how Europa is deformed by tidal forces.
The instrument team leader is Erwan Mazarico of NASA's Goddard Space Flight Center.
Launch and trajectory
Congress had originally mandated that Europa Clipper be launched on NASA's Space Launch System (SLS) super heavy-lift launch vehicle, but NASA had requested that other vehicles be allowed to launch the spacecraft due to a foreseen lack of available SLS vehicles. The United States Congress's 2021 omnibus spending bill directed the NASA Administrator to conduct a full and open competition to select a commercial launch vehicle if the conditions to launch the probe on a SLS rocket cannot be met.
On January 25, 2021, NASA's Planetary Missions Program Office formally directed the mission team to "immediately cease efforts to maintain SLS compatibility" and move forward with a commercial launch vehicle.
On February 10, 2021, it was announced that the mission would use a 5.5-year trajectory to the Jovian system, with gravity-assist maneuvers involving Mars (March 1, 2025) and Earth (December 3, 2026). Launch was targeted for a 21-day period between October 10 and 30, 2024, giving an arrival date in April 2030, and backup launch dates were identified in 2025 and 2026.
The SLS option would have entailed a direct trajectory to Jupiter taking less than three years. One alternative to the direct trajectory was identified as using a commercial rocket, with a longer 6-year cruise time involving gravity assist maneuvers at Venus, Earth and/or Mars. Additionally, a launch on a Delta IV Heavy with a gravity assist at Venus was considered.
In July 2021 the decision was announced to launch on a Falcon Heavy rocket, in fully expendable configuration. Three reasons were given: reasonable launch cost (ca. $178 million), questionable SLS availability, and possible damage to the payload due to strong vibrations caused by the solid boosters attached to the SLS launcher. The move to Falcon Heavy saved an estimated US$2 billion in launch costs alone. NASA was not sure an SLS would be available for the mission since the Artemis program would use SLS rockets extensively, and the SLS's use of solid rocket boosters (SRBs) generates more vibrations in the payload than a launcher that does not use SRBs. The cost to redesign Europa Clipper for the SLS vibratory environment was estimated at US$1 billion.
Europa Clipper was launched on October 14, 2024, at 12:06 p.m. EDT from Launch Pad 39A at NASA's Kennedy Space Center in Florida. Hurricane Milton caused a launch attempt for October 10 to be scrubbed, resulting in the launch being finalized for October 14.
The trajectory of Europa Clipper will include a gravity assist from Mars on March 1, 2025, allowing it to speed further away from the Sun, then down towards the Sun and back out, and gain additional kinetic energy from an Earth gravity assist on December 3, 2026. The probe will then arc (reach aphelion) beyond Jupiter's orbit on October 4, 2029 before slowly falling into Jupiter's gravity well and executing its orbital insertion burn in April 2030.
, the trajectory in the Jupiter system is planned as follows. After entry into the Jupiter system, Europa Clipper will perform a flyby of Ganymede at an altitude of , which will reduce the spacecraft velocity by ~. This will be followed by firing the main engine at a distance of 11 Rj (Jovian radii), to provide a further ~ of delta-V, sufficient to insert the spacecraft into a 202-day orbit around Jupiter. Once the spacecraft reaches the apoapsis of that initial orbit, it will perform another engine burn to provide a ~ periapsis raise maneuver (PRM).
The spacecraft's cruise and science phases will overlap with the ESA's JUICE spacecraft, which was launched in April 2023 and will arrive at Jupiter in July 2031. Europa Clipper is due to arrive at Jupiter 15 months prior to JUICE, despite a launch date planned 18 months later, owing to a more powerful launch vehicle and a faster flight plan with fewer gravity assists.
Public outreach
To raise public awareness of the Europa Clipper mission, NASA undertook a "Message In A Bottle" campaign, i.e. an actual "Send Your Name to Europa" campaign on June 1, 2023, through which people around the world were invited to send their names as signatories to a poem called "In Praise of Mystery: A Poem for Europa" written by the U.S. Poet Laureate Ada Limón, for the 2.9-billion-kilometer (1.8-billion mi) voyage to Jupiter. The poem describes the connections between Earth and Europa.
The poem is engraved on Europa Clipper inside a tantalum metal plate, about 7 by 11 inches (18 by 28 centimeters), that seals an opening into the vault. The inward-facing side of the metal plate is engraved with the poem in the poet's own handwriting. The public participants' names are etched onto a microchip attached to the plate, within an artwork of a wine bottle surrounded by the four Galilean moons. After registering their names, participants received a digital ticket with details of the mission's launch and destination. According to NASA, 2,620,861 people signed their names to Europa Clipper's Message in a Bottle, most of whom were from the United States. Other elements etched on the inwards side together with the poem and names are the Drake equation, representations of the spectral lines of a hydrogen atom and the hydroxyl radical, together known as the water hole, and a portrait of planetary scientist Ron Greeley. The outward-facing panel features art that highlights Earth's connection to Europa. Linguists collected recordings of the word "water" spoken in 103 languages, from families of languages around the world. The audio files were converted into waveforms and etched into the plate. The waveforms radiate out from a symbol representing the American Sign Language sign for "water". The research organization METI International gathered the audio files for the words for "water", and its president Douglas Vakoch designed the water hole component of the message.
See also
References
Further reading
External links
NASA – Overview of Europa
2024 in Florida
October 2024 events in the United States
Space probes launched in 2024
Orbiters (space probe)
Missions to Jupiter
NASA programs
Solar System Exploration program
SpaceX
Europa (moon)
Message artifacts | Europa Clipper | [
"Astronomy"
] | 5,985 | [
"Message artifacts",
"Outer space"
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41,356,580 | https://en.wikipedia.org/wiki/Ionic%20hydrogenation | Ionic hydrogenation refers to hydrogenation achieved by the addition of a hydride to substrate that has been activated by an electrophile. Some ionic hydrogenations entail addition of H2 to the substrate and some entail replacement of a heteroatom with hydride. Traditionally, the method was developed for acid-induced reductions with hydrosilanes. Alternatively ionic hydrogenation can be achieved using H2. Ionic hydrogenation is employed when the substrate can produce a stable carbonium ion. Polar double bonds are favored substrates.
Using hydrosilanes
Because silicon (1.90) is more electropositive than hydrogen (2.20), hydrosilanes exhibit (mild) hydridic character. Hydrosilanes can serve as hydride donors to highly electrophilic organic substrates. Many alcohols, alkyl halides, acetals, orthoesters, alkenes, aldehydes, ketones, and carboxylic acid derivatives are suitable substrates. Such reactions often require Lewis acids. Only reactive electrophiles undergo reduction, selectivity is possible in reactions of substrates with multiple reducible functional groups.
Upon the generation of a carbocation, rate-determining hydride transfer from the organosilane occurs to yield a reduced product. Retention of configuration at silicon has been observed in silane reductions of chiral triaryl methyl chlorides in benzene. This result suggests that the exchange of chlorine for hydrogen occurs through σ-bond metathesis. Reductions in more polar solvents may involve silicenium ions.
Polymeric hydrosilanes, such as polymethylhydrosiloxane (PHMS) may be employed to facilitate separation of the reduced products from silicon-containing byproducts.
Using H2
The proton and hydride transfers are usually sequential or concerted. Usually ionic hydrogenation is shown to occur in two steps, starting with protonation.
R2C=Y + H+ → R2C+-YH
R2C+-YH + "H−" → R2CH-YH
Substrates
In the case of metal-catalyzed ionic hydrogenation, the substrates and their products must not bind to metal sites, as this would interfere with H2 activation. Ketones are the most common substrates. Less common are imines and N-heterocycles. The reaction can also be performed in reverse to effect hydrogenolysis. Liquid substrates can sometimes be hydrogenated without solvent, a goal of green chemistry.
Proton and hydride pairs
The most common hydrogenating pair is an organosilane as the hydride source (e.g. triethylsilane), and a strong oxyacid as the proton source (e.g. trifluoroacetic acid or triflic acid). The hydride and proton source cannot combine to give H2, which limits the hydricity and acidity of the H− and H+ sources, respectively.
Transition metal hydride complexes can be used in place of organosilanes as the hydride source. In these cases, triflic acid is a typical proton donor. Ketones such as benzophenones, and 1,1-disubstituted olefins are typical substrates. Hydrides of tungsten, chromium, osmium, and molybdenum complexes have also been reported. Tungsten dihydride complexes can hydrogenate ketones stoichiometrically with no external acids. One hydride serves as the hydride source, and the other serves as a proton source.
In the case of ionic hydrogenation, a dihydride complex is regenerated by hydrogen gas following hydrogenation. Typical catalysts are tungsten or molybdenum complexes. An example of such a catalyst is CpMo(CO)2(PR3)(OCR'2)]+ where M = W or Mo.
Related reactions
Transfer hydrogenation (TH) catalysts, e.g. Shvo catalyst, are related to catalysts used for ionic hydrogenation. TH catalysts however do not employ strong acids and both the H− and H+ components are covalently bonded to the complex prior to transfer to the unsaturated substrates. Typically, TH catalysts are more widely employed in organic synthesis.
Older literature
References
Hydrogenation | Ionic hydrogenation | [
"Chemistry"
] | 909 | [
"Hydrogenation"
] |
41,356,740 | https://en.wikipedia.org/wiki/Surotomycin | Surotomycin was an investigational oral antibiotic. This macrolide antibiotic was under investigation by Merck & Co (who acquired Cubist Pharmaceuticals) for the treatment of life-threatening diarrhea, commonly caused by the bacterium Clostridioides difficile. After reaching phase III in clinical trials, its production was discontinued in 2017 due to its non-superiority to current therapies.
See also
Cadazolid
Fidaxomicin
Ridinilazole
SCHEMBL19952957
References
Antibiotics
Macrolides | Surotomycin | [
"Biology"
] | 115 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
41,356,819 | https://en.wikipedia.org/wiki/Tabilautide | Tabilautide is an immunological agent. It was studied as a potential drug for the treatment of cancer, but development for this purpose has been discontinued.
References
Carboxamides
Abandoned drugs | Tabilautide | [
"Chemistry"
] | 42 | [
"Drug safety",
"Abandoned drugs"
] |
41,357,288 | https://en.wikipedia.org/wiki/Cisco%20Prime | Cisco Prime (Cisco Works before 2011, CiscoWorks before that) is a network management software suite comprising different software applications by Cisco Systems. Most applications are geared towards either Enterprise or Service Provider networks. There is a Cisco Network Registrar among those.
Cisco states that Cisco Prime applications have the same look and feel as each other. At least some of the Cisco Prime applications are packaged as both a traditional software package and a VMware image.
Applications
Cisco Prime for IT Product
• Offers comprehensive management of wired/wireless access, campus, and branch networks, rich visibility into end-user connectivity, and application performance assurance;
• The Cisco Prime Service Catalog is a self-service portal where users can order and manage any IT service, from data center to desktop. Whether end users order a mobile device, a virtual desktop, or an entire application-development environment in a private cloud, the Cisco Prime Service Catalog helps streamline the service request and delivery process.
• It provides deep application-aware network visibility and granular performance analytics, empowering network administrators to rapidly isolate and remediate problems and improve the user experience.
• Provides integrated, high-performance, reliable Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), and IP Address Management (IPAM) services for the enterprise network.
Voice and Video Collaboration Management
Cisco Prime Collaboration
Data Center Management
• (NAM) provides deep application-aware network visibility and granular performance analytics, empowering network administrators to isolate and remediate problems and rapidly improve the user experience.
• (NGA) Generates, unifies, and exports flow data in high-performance data centers, empowering network operations, engineering, and security teams to achieve operational efficiencies, improve service delivery, and harden network security.
• Cisco Prime Data Center Network Manager: (DCNM) combines the management of Ethernet and storage networks into a single dashboard to help network and storage administrators troubleshoot health and performance across the entire range of Cisco NX-OS platforms, including the Cisco Nexus and MDS 9000 Families, regardless of protocol type.
Service Provider Product Portfolio
• Analytics: Provide scalable, real-time, network-centric analytics that allows for adaptation to customer environments and use cases.
• Carrier Management: Simplify the lifecycle management of carrier-grade networks and services by automating service design, fulfillment, assurance, and analysis tasks.
• Cloud Automation Enable efficient delivery of cloud services by automating lifecycle management processes including provisioning, operations and resource management.
• Operational Systems Software Efficiently coordinate business and operational processes for rapid design, creation, and delivery of services.
• Endpoint Management Deploy scalable, flexible DNS, DHCP, IPAM, and AAA services, and connected home management.
• Voice and Video Collaboration Automate voice provisioning, real-time monitoring and proactive troubleshooting across Cisco Unified Communications and Cisco TelePresence systems.
Cloud Product Portfolio
• Cisco Intelligent Automation for Cloud Cisco Intelligent Automation for Cloud helps enable enterprise IT professionals and service providers deliver highly secure on-demand IT (ITaaS - IT as a service). By creating a more agile and cost-effective service-delivery vehicle, IT professionals can proactively meet the growing needs of a business.
• Cisco Prime Network Services Controller The Cisco Prime Network Services Controller (formerly the Cisco Virtual Network Management Center), provides centralized device and policy management for Cisco virtual services. The virtual appliance offers transparent, scalable, and automation-centric management for virtualized enterprise data center and multitenant cloud environments.
Network management | Cisco Prime | [
"Engineering"
] | 725 | [
"Computer networks engineering",
"Network management"
] |
41,357,352 | https://en.wikipedia.org/wiki/Soricidin | Soricidin is a paralytic oligopeptide found in the venomous saliva of the northern short-tailed shrew (Blarina brevicauda); in the wild, shrews use it to paralyze their prey (typically insects). Its name is a reference to "Soricidae", the family to which shrews belong.
In addition to blocking transmission of nerve impulses by inhibiting sodium channels, soricidin also inhibits the TRPV6 calcium channel, which is over-expressed in many epithelial-cell cancers; as a result, soricidin is able to selectively induce apoptosis in breast, ovarian, and prostate cancer.
It is 54 amino acids long. It was first extracted and identified in 2000, as a result of basic research by Jack Stewart of Mount Allison University.
References
Vertebrate toxins
Ion channel toxins
Peptides
Shrews | Soricidin | [
"Chemistry"
] | 198 | [
"Biomolecules by chemical classification",
"Peptides",
"Molecular biology"
] |
41,358,691 | https://en.wikipedia.org/wiki/Hydrodynamic%20quantum%20analogs | In physics, the hydrodynamic quantum analogs refer to experimentally-observed phenomena involving bouncing fluid droplets over a vibrating fluid bath that behave analogously to several quantum-mechanical systems. The experimental evidence for diffraction through slits has been disputed, however, though the diffraction pattern of walking droplets is not exactly the same as in quantum physics, it does appear clearly in the high memory parameter regime (at high forcing of the bath) where all the quantum-like effects are strongest.
A droplet can be made to bounce indefinitely in a stationary position on a vibrating fluid surface. This is possible due to a pervading air layer that prevents the drop from coalescing into the bath. For certain combinations of bath surface acceleration, droplet size, and vibration frequency, a bouncing droplet will cease to stay in a stationary position, but instead “walk” in a rectilinear motion on top of the fluid bath. Walking droplet systems have been found to mimic several quantum mechanical phenomena including particle diffraction, quantum tunneling, quantized orbits, the Zeeman Effect, and the quantum corral.
Besides being an interesting means to visualise phenomena that are typical of the quantum-mechanical world, floating droplets on a vibrating bath have interesting analogies with the pilot wave theory, one of the many interpretations of quantum mechanics in its early stages of conception and development. The theory was initially proposed by Louis de Broglie in 1927. It suggests that all particles in motion are actually borne on a wave-like motion, similar to how an object moves on a tide. In this theory, it is the evolution of the carrier wave that is given by the Schrödinger equation. It is a deterministic theory and is entirely nonlocal. It is an example of a hidden variable theory, and all non-relativistic quantum mechanics can be accounted for in this theory. The theory was abandoned by de Broglie in 1932, gave way to the Copenhagen interpretation, but was revived by David Bohm in 1952 as De Broglie–Bohm theory. The Copenhagen interpretation does not use the concept of the carrier wave or that a particle moves in definite paths until a measurement is made.
Physics of bouncing and walking droplets
History
Floating droplets on a vibrating bath were first described in writing by Jearl Walker in a 1978 article in Scientific American.
In 2005, Yves Couder and his lab were the first to systematically study the dynamics of bouncing droplets and discovered most of the quantum mechanical analogs.
John Bush and his lab expanded upon Couder's work and studied the system in greater detail. In 2015 three separate groups, including John Bush, attempted to reproduce the effect and were unsuccessful.
Stationary bouncing droplet
A fluid droplet can float or bounce over a vibrating fluid bath because of the presence of an air layer between the droplet and the bath surface. The behavior of the droplet depends on the acceleration of the bath surface. Below a critical acceleration, the droplet will take successively smaller bounces before the intervening air layer eventually drains from underneath, causing the droplet to coalesce. Above the bouncing threshold, the intervening air layer replenishes during each bounce so the droplet never touches the bath surface. Near the bath surface, the droplet experiences equilibrium between inertial forces, gravity, and a reaction force due to the interaction with the air layer above the bath surface. This reaction force serves to launch the droplet back above the air like a trampoline. Molacek and Bush proposed two different models for the reaction force.
Walking droplet
For a small range of frequencies and drop sizes, a fluid droplet on a vibrating bath can be made to “walk” on the surface if the surface acceleration is sufficiently high (but still below the Faraday instability). That is, the droplet does not simply bounce in a stationary position but instead wanders in a straight line or in a chaotic trajectory. When a droplet interacts with the surface, it creates a transient wave that propagates from the point of impact. These waves usually decay, and stabilizing forces keep the droplet from drifting. However, when the surface acceleration is high, the transient waves created upon impact do not decay as quickly, deforming the surface such that the stabilizing forces are not enough to keep the droplet stationary. Thus, the droplet begins to “walk.”
Quantum phenomena on a macroscopic scale
A walking droplet on a vibrating fluid bath was found to behave analogously to several different quantum mechanical systems, namely particle diffraction, quantum tunneling, quantized orbits, the Zeeman effect, and the quantum corral.
Single and double slit diffraction
It has been known since the early 19th century that when light is shone through one or two small slits, a diffraction pattern appears on a screen far from the slits. Light has wave-like behavior, and interferes with itself through the slits, creating a pattern of alternating high and low intensity. Single electrons also exhibit wave-like behavior as a result of wave-particle duality. When electrons are fired through small slits, the probability of the electron striking the screen at a specific point shows an interference pattern as well.
In 2006, Couder and Fort demonstrated that walking droplets passing through one or two slits exhibit similar interference behavior. They used a square shaped vibrating fluid bath with a constant depth (aside from the walls). The “walls” were regions of much lower depth, where the droplets would be stopped or reflected away. When the droplets were placed in the same initial location, they would pass through the slits and be scattered, seemingly randomly. However, by plotting a histogram of the droplets based on scattering angle, the researchers found that the scattering angle was not random, but droplets had preferred directions that followed the same pattern as light or electrons. In this way, the droplet may mimic the behavior of a quantum particle as it passes through the slit.
Despite that research, in 2015 three teams: Bohr and Andersen's group in Denmark, Bush's team at MIT, and a team led by the quantum physicist Herman Batelaan at the University of Nebraska set out to repeat the Couder and Fort's bouncing-droplet double-slit experiment. Having their experimental setups perfected, none of the teams saw the interference-like pattern reported by Couder and Fort. Droplets went through the slits in almost straight lines, and no stripes appeared.
It has since been shown that droplet trajectories are sensitive to interactions with container boundaries, air currents, and other parameters. Though the diffraction pattern of walking droplets is not exactly the same as in quantum physics, and is not expected to show a Fraunhofer-like dependence of the number of peaks on the slit width, the diffraction pattern does appear clearly in the high memory regime (at high forcing of the bath).
Quantum tunneling
Quantum tunneling is the quantum mechanical phenomenon where a quantum particle passes through a potential barrier. In classical mechanics, a classical particle could not pass through a potential barrier if the particle does not have enough energy, so the tunneling effect is confined to the quantum realm. For example, a rolling ball would not reach the top of a steep hill without adequate energy. However, a quantum particle, acting as a wave, can undergo both reflection and transmission at a potential barrier. This can be shown as a solution to the time dependent Schrödinger Equation. There is a finite, but usually small, probability to find the electron at a location past the barrier. This probability decreases exponentially with increasing barrier width.
The macroscopic analogy using fluid droplets was first demonstrated in 2009. Researchers set up a square vibrating bath surrounded by walls on its perimeter. These “walls” were regions of lower depth, where a walking droplet may be reflected away. When the walking droplets were allowed to move around in the domain, they usually were reflected away from the barriers. However, surprisingly, sometimes the walking droplet would bounce past the barrier, similar to a quantum particle undergoing tunneling. In fact, the crossing probability was also found to decrease exponentially with increasing width of the barrier, exactly analogous to a quantum tunneling particle.
Quantized orbits
When two atomic particles interact and form a bound state, such the hydrogen atom, the energy spectrum is discrete. That is, the energy levels of the bound state are not continuous and only exist in discrete quantities, forming “quantized orbits.” In the case of a hydrogen atom, the quantized orbits are characterized by atomic orbitals, whose shapes are functions of discrete quantum numbers.
On the macroscopic level, two walking fluid droplets can interact on a vibrating surface. It was found that the droplets would orbit each other in a stable configuration with a fixed distance apart. The stable distances came in discrete values. The stable orbiting droplets analogously represent a bound state in the quantum mechanical system. The discrete values of the distance between droplets are analogous to discrete energy levels as well.
Zeeman effect
When an external magnetic field is applied to a hydrogen atom, for example, the energy levels are shifted to values slightly above or below the original level. The direction of shift depends on the sign of the z-component of the total angular momentum. This phenomenon is known as the Zeeman Effect.
In the context of walking droplets, an analogous Zeeman Effect can be demonstrated by observing orbiting droplets in a vibrating fluid bath. The bath is also brought to rotate at a constant angular velocity. In the rotating bath, the equilibrium distance between droplets shifts slightly farther or closer. The direction of shift depends on whether the orbiting drops rotate in the same direction as the bath or in opposite directions. The analogy to the quantum effect is clear. The bath rotation is analogous to an externally applied magnetic field, and the distance between droplets is analogous to energy levels. The distance shifts under an applied bath rotation, just as the energy levels shift under an applied magnetic field.
Quantum corral
Researchers have found that a walking droplet placed in a circular bath does not wander randomly, but rather there are specific locations the droplet is more likely to be found. Specifically, the probability of finding the walking droplet as a function of the distance from the center is non-uniform and there are several peaks of higher probability. This probability distribution mimics that of an electron confined to a quantum corral.
See also
Pilot-wave models
De Broglie–Bohm theory
Superfluid vacuum theory
Quantum hydrodynamics
References
External links
Research on hydrodynamic quantum analogues Prof. John Bush (MIT)
Wired "Have We Been Interpreting Quantum Mechanics Wrong This Whole Time?" 2014
Quantum models | Hydrodynamic quantum analogs | [
"Physics"
] | 2,174 | [
"Quantum models",
"Quantum mechanics"
] |
41,359,304 | https://en.wikipedia.org/wiki/Iron%20powder | Iron powder has several uses; for example production of magnetic alloys and certain types of steels.
Iron powder is formed as a whole from several other iron particles. The particle sizes vary anywhere from 20-200 μm. The iron properties differ depending on the production method and history of a specific iron powder. There are three types of iron powder classifications: reduced iron powder, atomized powder, and electrolytic iron powder. Each type is used in various applications depending on their properties. There is very little difference in the visual appearances of reduced iron powder and atomized iron powder.
Applications
Automobiles
Most iron powders are used for automobile parts.
Engine parts
Cam shaft pulley
Cam shaft sprocket
Crank shaft pulley
Crank shaft sprocket
Cap crank bearing
Valve guide
Valve seat
Rocker arm chip
Oil pump inner rotor
Oil pump outer rotor
Steering parts, suspension, and brake parts
Power steering rotor cam ring
Pressure plate
Rack guide
Shock absorber
Ball joint
ABS sensor
Seats and door parts
Seat lifter cam set
Door mirror plate clutch
Striker
Slider
Transmission parts
M/T Synchronizer hub
A/T Hub clutch
Synchronizer ring
Retaining plate
Synchronizer key
Pressure plate
Shift fork
Turbine hub
Weight governor
Cam stater T. C.
Outer race
Other
Iron powder is also used for the following:
Bearings and filter parts
Machine parts
Hand Warmers
High strength/wear-resistant parts
Magnetic materials
Friction parts (mainly automobile parts)
As a method of hydrogen storage
As a fuel
Oxygen scavengers – can be in small pouches separate from food or directly added to food, in which case it also serves as food fortification
External links
See also
Metal powder
Thermite
References
Iron
Iron objects
Powders | Iron powder | [
"Physics"
] | 341 | [
"Materials stubs",
"Materials",
"Powders",
"Matter"
] |
41,359,517 | https://en.wikipedia.org/wiki/Recoil%20%28rheology%29 | Recoil is a rheological phenomenon observed only in non-Newtonian fluids that is characterized by a moving fluid's ability to snap back to a previous position when external forces are removed. Recoil is a result of the fluid's elasticity and memory where the speed and acceleration by which the fluid moves depends on the molecular structure and the location to which it returns depends on the conformational entropy. This effect is observed in numerous non-Newtonian liquids to a small degree, but is prominent in some materials such as molten polymers.
Memory
The degree to which a fluid will “remember” where it came from depends on the entropy. Viscoelastic properties in fluids cause them to snap back to entropically favorable conformations. Recoil is observed when a favorable conformation is in the fluid's recent past. However, the fluid cannot fully return to its original position due to energy losses stemming from less than perfect elasticity.
Recoiling fluids display fading memory meaning the longer a fluid is elongated, the less it will recover. Recoil is related to characteristic time, an estimate of the order of magnitude of reaction for the system. Fluids that are described as recoiling generally have characteristic times on the order of a few seconds. Although recoiling fluids usually recover relatively small distances, some molten polymers can recover back to 1/10 of the total elongation. This property of polymers must be accounted for in polymer processing.
Demonstrations of Recoil
When a spinning rod is placed in a polymer solution, elastic forces generated by the rotation motion cause fluid to climb up the rod (a phenomenon known as the Weissenberg effect). If the torque being applied is immediately brought to a stop, the fluid recoils down the rod.
When a viscoelastic fluid being poured from a beaker is quickly cut with a pair of scissors, the fluid recoils back into the beaker.
When fluid at rest in a circular tube is subjected to a pressure drop, a parabolic flow distribution is observed that pulls the liquid down the tube. Immediately after the pressure is alleviated, the fluid recoils backward in the tube and forms a more blunt flow profile.
When Silly Putty is rapidly stretched and held at an elongated position for a short period of time, it springs back. However, if it is held at an elongated position for a longer period of time, there is very little recovery and no visible recoil.
References
Fluid dynamics
Rheology
Non-Newtonian fluids | Recoil (rheology) | [
"Chemistry",
"Engineering"
] | 493 | [
"Piping",
"Chemical engineering",
"Rheology",
"Fluid dynamics"
] |
41,359,677 | https://en.wikipedia.org/wiki/Thermosalinograph | The Thermosalinograph or TSG is an measuring instrument mounted near the water intake of ships to continuously measure sea surface temperature and conductivity while the ship is in motion. Various programs have been developed to assist in the collection and analysis of data from a TSG. The data can be used to calculate salinity, density, sound velocity within the water, and other parameters. There are various types of thermosalinographs available on the market today.
Background
Programs collecting TSG data
NOAA fleet
Ship of Opportunity Program (SOOP)
Global Ocean Observing System (GOOS)
GOSUD Global Ocean Surface Underway Data (http://www.gosud.org)
Measurement devices
The thermosalinograph uses a conductivity cell to measure conductivity, which can then be translated into a value of salinity. Also a thermistor cell measures the temperature of the surface water, which when combined with the conductivity can be used calculate the density of the water and the sound velocity within it.
Types
Sources of error
Water is measured in the engine room, which can cause biases from heat in the room.
References
Water transport
Measuring instruments | Thermosalinograph | [
"Technology",
"Engineering"
] | 238 | [
"Measuring instruments"
] |
41,359,740 | https://en.wikipedia.org/wiki/Anochetus%20intermedius | Anochetus intermedius is an extinct species of ant in the subfamily Ponerinae known from two possibly Miocene fossils found on Hispaniola. A. intermedius is one of eight species in the ant genus Anochetus to have been described from fossils found in Dominican amber and is one of a number of Anochetus species found in the Greater Antilles.
History and classification
Anochetus intermedius is known from a solitary fossil insect which, along with two flies, three other ants, and two springtails, is an inclusion in a transparent yellow chunk of Dominican amber. The amber was produced by the extinct Hymenaea protera, which formerly grew on Hispaniola, across northern South America and up to southern Mexico. The specimen was collected from an undetermined amber mine in fossil bearing rocks of the Cordillera Septentrional mountains of northern Dominican Republic. The amber dates from at least the Burdigalian stage of the Miocene, based on studying the associated fossil foraminifera and may be as old as the Middle Eocene, based on the associated fossil coccoliths. This age range is due to the host rock being secondary deposits for the amber, and the Miocene the age range is only the youngest that it might be.
At the time of description, the holotype specimen was preserved in the Natural History Museum, London amber collections in London, England. The holotype fossil was first studied by entomologist Maria L. De Andrade of the University of Basle with her 1991 type description of the new species being published in the journal Stuttgarter Beiträge zur Naturkunde. Serie B (Geologie und Paläontologie). The specific epithet is derived from the Latin intermedius meaning "intermediate".
The species is one of eight Anochetus which have been described from Dominican amber. Two species were described prior to A. intermedius, A. corayi in 1980 and A. brevidentatus in 1991. The remaining five species; A. ambiguus, A. conisquamis, A. dubius, A. exstinctus, and A. lucidus were all described by De Andrade in the same 1994 paper as A. intermedius. A number of modern species live in the Greater Antilles, with at least three modern species found on Hispaniola.
Description
The Anochetus intermedius type specimen is fairly well preserved, though some body structures were lost prior to entombment and the specimen shows distortions along its full length from the resin flowing after entombment. The specimen has an estimated body length of , with a long head and long mandibles. The overall coloration of the body is a chestnut-yellow, with the coxae, femora, trochanters and mandible blades a yellowish tone, while the head, mandible tips, antennae, tibiae and tarsi are all brownish. The mandibles are one quarter times longer than the width of the head and just over the length, slightly flaring in width from the base to tips and have seven teeth on the left mandible, eight teeth on the right, all of which decrease in size from the tips to the bases. The apical three teeth on each mandible blade are elongated and slender for grasping prey. Both the mesonotum and pronotum have a slight "u" shaped profile, with the undersides of each curved upwards. The propodium sports short spines, long, on the rear edge, while the petiole has longer spines, , centrally placed.
References
†Anochetus intermedius
Fossil ant taxa
Burdigalian life
Miocene insects of North America
Prehistoric insects of the Caribbean
Fauna of Hispaniola
Insects of the Dominican Republic
Dominican amber
Fossil taxa described in 1994
Species known from a single specimen | Anochetus intermedius | [
"Biology"
] | 792 | [
"Individual organisms",
"Species known from a single specimen"
] |
41,362,059 | https://en.wikipedia.org/wiki/Kolmogorov%27s%20two-series%20theorem | In probability theory, Kolmogorov's two-series theorem is a result about the convergence of random series. It follows from Kolmogorov's inequality and is used in one proof of the strong law of large numbers.
Statement of the theorem
Let be independent random variables with expected values and variances , such that converges in and converges in . Then converges in almost surely.
Proof
Assume WLOG . Set , and we will see that with probability 1.
For every ,
Thus, for every and ,
While the second inequality is due to Kolmogorov's inequality.
By the assumption that converges, it follows that the last term tends to 0 when , for every arbitrary .
References
Durrett, Rick. Probability: Theory and Examples. Duxbury advanced series, Third Edition, Thomson Brooks/Cole, 2005, Section 1.8, pp. 60–69.
M. Loève, Probability theory, Princeton Univ. Press (1963) pp. Sect. 16.3
W. Feller, An introduction to probability theory and its applications, 2, Wiley (1971) pp. Sect. IX.9
Probability theorems | Kolmogorov's two-series theorem | [
"Mathematics"
] | 238 | [
"Theorems in probability theory",
"Mathematical theorems",
"Mathematical problems"
] |
41,362,687 | https://en.wikipedia.org/wiki/Khalil%20Qureshi | Khalil Ahmad Qureshi (Urdu: خليل احمد قريشى; HI, SI), is a Pakistani physical chemist and the professor of physical chemistry at the Punjab University. He has published notable papers in nuclear physical chemistry in international scientific journals as well contributing in the advancement of the scientific applications of the civilian usage of the fuel cycle.
Biography
Early life and education
A native of Lahore, Qureshi subsequently attended the Punjab University to study chemistry where he graduated with BSc in chemistry. For his higher studies, he went to United Kingdom to attend Imperial College London. He earned MSc in Chemical Technology and worked towards gaining the DIC in physical metallurgy. At the Imperial College, he joined the doctoral group led by Thomas West and David Craig. He earned his PhD in physical chemistry under the supervision of David Craig, writing his thesis on Physico-chemical studies of the vapour deposition of Al2O3, in 1972.
Pakistan Atomic Energy Commission
He briefly taught physical chemistry at the London University before moving to Pakistan. Upon his return, he joined the Pakistan Atomic Energy Commission (PAEC) and took the professorship of nuclear chemistry at the Pakistan Institute of Nuclear Science and Technology (PINSTECH). Subsequently, he joined the clandestine atomic bomb project's chemistry section led by fellow chemist Iqbal Hussain Qureshi.
Munir Ahmad Khan, chairman PAEC, had him partially take over the "R-Labs" at PAEC to engage research in chemical explosives. Initially, the research was concentrated towards development of the HMX, a non-toxic explosive that was produced as a by-product of the RDX process. In the 1970s, he founded the Metallurgical Laboratory (ML) where he also moved majority of the staff to undertake research in metallurgy. He then led a team of chemists who supervised the physical conversion of UF6 into solid metal before coating and machining the metal. During this time, he also led the research on using chemical and metallurgical industrial techniques and reduction furnaces to produce metal from the Highly enriched uranium. Due to the sensitivity of the project and concerns of fellow theorist Dr. AQ Khan, the program was moved to KRL in the 1980s.
Research and science activism
While at PAEC, Qureshi joined the chemistry department of Quaid-e-Azam University as an associate professor. In the 1990s, he joined the Punjab University to teach post-graduate course on physical chemistry. In the 2000s, he joined the Lahore University of Management Sciences's School of Science and Engineering as director of engineering and safety.
Over the years, he became known for his strong scientific advocacy of peaceful usage of nuclear energy, safety, and security, following the Fukushima disaster. A member of Khwarizmi Science Society, he has lectured on safety issues regarded the nuclear power and topics in nuclear chemistry. He has also authored numerous articles on chemical safety and securities around the world in world's leading research journal. In 2011, he lectured on physical chemistry and spoke about how nuclear technology was being used currently and different ways of disposing nuclear waste at the Forman Christian College University in Lahore. He is the recipient of Pakistan's highest honours– the Hilal-i-Imtiaz bestowed in 2003 and the Sitara-e-Imtiaz bestowed in 1999 by the Government of Pakistan.
Honors and recognition
Hilal-i-Imtiaz (2003)
Sitara-e-Imtiaz (1999)
President, Pakistan Materials Research Society
Fellow, Pakistan Institute of Metallurgical Engineers
Fellow of Pakistan Nuclear Society
References
External links
Harnessing Nuclear Energy
Living people
Scientists from Lahore
University of the Punjab alumni
Alumni of Imperial College London
Academic staff of Lahore University of Management Sciences
Academics of the University of London
Academic staff of the University of the Punjab
Academic staff of Quaid-i-Azam University
Pakistani chemical engineers
Project-706
Physical chemists
Pakistani science writers
Recipients of Hilal-i-Imtiaz
Recipients of Sitara-i-Imtiaz
Year of birth missing (living people)
Nuclear weapons scientists and engineers | Khalil Qureshi | [
"Chemistry"
] | 837 | [
"Physical chemists"
] |
67,106,299 | https://en.wikipedia.org/wiki/Simjacker | Simjacker is a cellular software exploit for SIM cards discovered by AdaptiveMobile Security. 29 countries are vulnerable according to ZDNet. The vulnerability has been exploited primarily in Mexico, but also Colombia and Peru, according to the Wall Street Journal, where it was used to track the location of mobile phone users without their knowledge.
History
The vulnerability was discovered and reported to the GSM Association through its coordinated vulnerability disclosure process by Cathal Mc Daid of AdaptiveMobile Security in 2019. It was first reported publicly on 12 September 2019. A technical paper and presentation was made available at the VirusBulletin conference on 3 October 2019.
Technical information
The attack works by exploiting a vulnerability in a UICC/SIM card library called the S@T Browser. A specially formatted binary text message is sent to the victim handset, which contains a set of commands to be executed by the S@T Browser environment in the UICC. As the S@T Browser environment has access to a subset of SIM Toolkit commands, the attackers used this vulnerability to instruct the UICC to request IMEI and location information from the handset via SIM Toolkit commands. Once this was obtained the UICC then instructs the handset to exfiltrate this information to the attackers within another text message. Other types of attacks are also possible using the S@T Browser, such as forcing a mobile device to open a webpage or to make a phone call.
The attack differed from previously reported SIM card attacks as those required the SIM key to be obtained. The Simjacker attack does not require a SIM key, only that the SIM card has the S@T Browser library installed on it, and that the binary messages containing the S@T Browser commands can be sent to the victim.
Simjacker was registered in the Common Vulnerabilities and Exposures database as CVE-2019-16256 and CVE-2019-16257, and by the GSM Association in its Coordinated Vulnerability Disclosure process as CVD-2019-0026
Impact
The vulnerability was estimated to affect UICCs in at least 61 mobile operators in 29 countries, with estimates between a few hundred million to over a billion SIM cards affected. The researcher reported that the most probable, conservative estimate is that mid to high hundreds of millions of SIM cards globally are affected.
The vulnerability was being actively exploited primarily in Mexico, with thousands of mobile phone users being tracked by a surveillance company over the previous 2 years using this exploit.
Mitigation
Mobile phone users can use a tool from SRLabs to see if their SIM card is vulnerable.
References
External links
Computer security exploits | Simjacker | [
"Technology"
] | 535 | [
"Computing stubs",
"Computer security exploits"
] |
67,106,529 | https://en.wikipedia.org/wiki/The%20Zuckerberg%20Institute%20for%20Water%20Research | Zuckerberg Institute for Water Research (ZIWR) is one of three research institutes constituting the Jacob Blaustein Institutes for Desert Research, a faculty of Ben-Gurion University of the Negev (BGU). The ZIWR is located on BGU's Sede Boqer Campus in Midreshet Ben-Gurion in Israel's Negev Desert, and hosts researchers who focus on developing new technologies to provide drinking water and water for agricultural and industrial use and to promote the sustainable use of water resources. The ZIWR encompasses the Department of Environmental Hydrology and Microbiology, and the Department of Desalination and Water Treatment.
History
The Zuckerberg Institute for Water Research was founded in 2002 and was named for Roy J. Zuckerberg, Senior Director of the Goldman Sachs Group and a philanthropist, based in New York City. The ZIWR is one of three institutes currently constituting the Jacob Blaustein Institutes for Desert Research, which were originally established in 1974. In 2016, the estate of Dr. Howard and Lottie Marcus made a donation of $400 million dollars to Ben-Gurion University, believed to be the largest gift ever to a university in Israel, with a portion of it going to the Zuckerberg Institute for Water Research for research into water resources and desalination technologies.
Academic programs
The Institute runs two department: The Department of Environmental Hydrology and Microbiology, and the Department of Desalination and Water Treatment. It also offers an MSc degree in Hydrology and Water Quality, in collaboration with the Albert Katz International School for Desert Studies, which is located at BGU's Sde Boker Campus.
Department of Environmental Hydrology and Microbiology
The Department of Environmental Hydrology and Microbiology hosts researchers who specialize in hydrology, hydrogeology, chemistry, and microbiology. Some of their particular research areas include flow and transport processes, remediation of contaminated water, and biological treatment of wastewater.
Department of Desalination and Water Treatment
The Department of Desalination and Water Treatment employs researchers who focus on various aspects of desalination and water treatment processes including the improvement and development of membranes for reverse osmosis, forward osmosis, and nanofiltration processes; processes to eliminate toxic materials from industrial effluents and polluted groundwater; and brine concentrate management.
MSc in Hydrology and Water Quality
This master's degree program, offered through the Albert Katz International School for Desert Studies, aims to introduce students to research in water sciences with the goal of improving human life in drylands and the development of policies for the sustainable use of water resources. The program offers the following tracks of study: 1. Water Resources, 2. Desalination and Water Treatment, and 3. Microbiology and Water Quality.
Research
Researchers from the ZIWR were involved in studies related to the COVID-19 pandemic. In the first, a study that was led by a team of researchers from the ZIWR and published in Nature Sustainability found that coronaviruses can persist in wastewater for several days, possibly leading to the spread of these viruses to humans. In another study, ZIWR researchers, in cooperation with scientists from Rice University in Houston, Texas, developed a laser-induced graphene technology that can filter airborne COVID-19 particles.
References
Ben-Gurion University of the Negev
Research institutes in Israel
Water desalination
Hydrology organizations
Water treatment
Research institutes established in 2002 | The Zuckerberg Institute for Water Research | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 710 | [
"Hydrology",
"Water desalination",
"Water treatment",
"Water pollution",
"Environmental engineering",
"Water technology",
"Hydrology organizations"
] |
67,107,447 | https://en.wikipedia.org/wiki/Transform%20magazine | Transform magazine is a quarterly global print and online business magazine covering brand strategy and design. It is published by Cravenhill Publishing, an independent publishing company, which also publishes Communicate (magazine).
It is targeted to brand design and strategy agencies and in-house brand and marketing professionals.
History
In 2009, Cravenhill Publishing launched the inaugural Transform Awards, to celebrate rebranding, repositioning and brand transformation. In 2014 the company launched Transform magazine, which coincided with the global expansion of the awards programme.
It was shortlisted at the PPA Independent Publisher Awards 2014, in both the Best Launch or Relaunch category and the Front Cover of the Year category.
The Transform Awards
Transform magazine organises the Transform Awards benchmarking brand strategy and creativity. The awards programs take place in the following cities for the following markets.
For Europe, held annually in London. Launched 20092020 Grand Prix winner - Scala Radio and Thinkfarm 2020 Best Overall Visual Identity winner - Aktuel and Brand Brothers
For Middle East and Africa, held annually in Dubai. Launched 20142020 Grand Prix winner - DXB (Dubai Airports) and Landor&Fitch 2020 Best Overall Visual Identity winner - ila by Bank ABC and Superunion
For Asia, held annually in Shanghai. Launched in 2014. 2020 Grand Prix winner - Volkswagen Group China and MetaDesign China Limited 2020 Best Overall Visual Identity winner - Tencent Music Entertainment and Superunion
For North America, held annually in New York. Launched in 2015. 2020 Grand Prix winner - ASSA ABLOY / Yale and GW+Co 2020 Best Overall Visual Identity winner - Move United and Superunion
For the Nordic countries, inaugural event held online. Launched in 2020. 2020 Grand Prix winner - University Museum of Bergen and Haltenbanken
For Australia and New Zealand, inaugural event held online. Launched in 2020. 2020 Grand Prix winner - West Coast Council and For the People 2020 Best Overall Visual Identity winner - Australian National Maritime Museum and Frost*collective
For India. Launched in 2021
References
Business magazines published in the United Kingdom
Design magazines
Magazines established in 2014
Design awards | Transform magazine | [
"Engineering"
] | 425 | [
"Design magazines",
"Design",
"Design awards"
] |
67,107,506 | https://en.wikipedia.org/wiki/Polyuronide | Polyuronide is a polymeric substance which consists of uronic acid units that have glycosidic linkages which are commonly combined with monosaccharides.
Sources
Polyuronide widely occurs in soil and plants (such as gums and pectic substances).
Studies
There are many scientific studies about polyuronide in plants. However, the most studied is the presence of polyuronide in avocado and tomato. There is also a study about its occurrence in barrel cactus.
Examples
Glucoronic acid
Galactoronic acid
References
External links
The Free Dictionary: polyuronides
Organic polymers
Uronic acids | Polyuronide | [
"Chemistry"
] | 127 | [
"Organic compounds",
"Organic polymers"
] |
67,107,510 | https://en.wikipedia.org/wiki/Gagik%20Khachatryan%20%28politician%29 | Gagik Gurgeni Khachatryan (; born November 26, 1955) is an Armenian politician who held various positions in Armenia's state bureaucracy, notably serving as chairman of the State Revenue Committee from 2008 to 2014 and minister of finance from 2014 to 2016. He was popularly known as the "super minister" due to his numerous responsibilities. He is currently the defendant in a corruption-related criminal case in Armenia.
Early life and education
Gagik Khachatryan was born in the village of Amasia in the Armenian SSR in 1955. He graduated from Yerevan Polytechnic University in 1977, majoring in industrial electronics. In 1987, he graduated from the Yerevan Institute of National Economy, receiving a degree in accounting and analysis of economic activity.
Professional experience
1977–1978 worked as an electronics engineer in “Electron” factory
1978–1984 served as the second secretary of the initial organization of the Lenin Communist Youth Union Nairi regional committee
1984–1986 worked as the head of the department of the State Agro-technical school after G. Aghajanyan
1986–1989 served as the secretary of the initial party organization of Nor-Geghi State Technical College
1989–1996 – First Deputy Director of "Nairi" agro-firm
1996 worked as the Deputy Head of Hrazdan Tax Inspectorate
1996–1999 – Head of Mashtots Region Tax Inspectorate
1999–2000 – Head of the Tax Inspectorate of Erebuni region
2000 – Head of the Tax Inspectorate of Shahumyan region
2000–2001 – Deputy Head of the Tax Department of the RA Ministry of State Revenues
2001–2008 – Deputy Chairman of the RA State Customs Committee
April 15 – June 4, 2008 – Acting Chairman of the RA State Customs Committee
On June 4, 2008, by the decision of the Prime Minister of Armenia, he was relieved of the post of Deputy Chairman of the State Customs Committee under the Government of Armenia
On June 4, 2008, by the decree of the President of Armenia he was appointed as the Chairman of the State Customs Committee of Armenia
On August 20, 2008, by the decree of the President of Armenia he was appointed as the Chairman of the State Revenue Committee of Armenia
On April 26, 2014, he was relieved of the post of Chairman of the State Revenue Committee under the Government of Armenia by the decree of the President of Armenia
On April 26, 2014, by the Decree of the President of Armenia he was appointed Minister of Finance of Armenia.
Personal life
Gagik Khachatryan is married and has two sons and one daughter. His sons, Gurgen and Artyom Khachatryan, are entrepreneurs and the co-founders of Galaxy Group of Companies. As evidenced by the interview given to banks.am, Khachatryan’s two sons have never had involvement in politics or state work, and have strictly engaged in business. In 2019, they announced the “Innovation and Technology Park” project in Yerevan, with an estimated number of 6,000 jobs.
Legal issues
Khachatryan is currently the accused in major corruption-related case in Armenia. The accusing side claims that he caused $41 million worth of damages to the Armenian state. His two sons (who are currently wanted in Armenia) and two of his nephews are also accused in corruption-related cases.
In May 2022, the US government announced that it planned to seize a mansion in Los Angeles belonging to Khachatryan, contending that it was bought using bribe money. A trust representing Khachatryan and his sons bought the mansion for $14.4 million in 2011. In July 2024, the US Justice Department announced that it had reached a settlement to recover the property. Under the terms of the settlement, the mansion will be forfeited to the US government, which will then sell the property and retain 85% of the net proceeds of the sale. The remaining proceeds will be delivered to Khachatryan's sons and a corporation they own. Some or all of the forfeited proceeds will be transferred to Armenia.
Titles and awards
On December 29, 2011, Gagik Khachatryan was awarded the special rank of Lieutenant General of the Customs Service by the decree of the president of Armenia. He received the Medal of Anania Shirakatsi in 2012.
References
1955 births
Living people
National Polytechnic University of Armenia alumni
Armenian State University of Economics alumni
Electronics engineers
People from Shirak Province
Finance ministers of Armenia | Gagik Khachatryan (politician) | [
"Engineering"
] | 901 | [
"Electronics engineers",
"Electronic engineering"
] |
67,107,683 | https://en.wikipedia.org/wiki/Victor%20Kullberg | Victor Kullberg (1824–1890) was one of London's most famous watchmakers, described by one authority as "one of the most brilliant and successful horologists of the 19th century."
Early life
Jakob Victor Kullberg was born in Visby on the Swedish island of Gotland on 13 August 1824 to Johan Kullberg and Hedvig Christina Ahlstrom. At the age of sixteen he was apprenticed to a local watchmaker where he learnt how to make every part of a chronometer by hand. At the end of his apprenticeship he travelled to Copenhagen where he entered the service of Louis Urban Jürgensen, son of the famous chronometer maker Urban Jürgensen. After attending the 1851 Great Exhibition Kullberg decided to relocate to London and start his own enterprise as an escapement maker.
Career
Kullberg's superb escapements soon established his reputation as one of England's premier chronometer and watch manufacturers. His innovations in marine chronometers and other horological objects earned him nine gold medals, various silver medals, and ‘Grand Diploma of Honor’ at various Universal and national exhibitions. He regularly submitted his marine chronometers to the annual competition held at the Greenwich Observatory, winning ten times between 1862 and 1890, a record for any one person in the late 19th century. Kullberg is mostly known for his further development of compensation balances, eliminating middle-temperature errors, and his use of reverse fusée. His company V. Kullberg, was listed as maker to the Admiralty, The Indian & Colonial Governments and the navies of many countries. From the 1880s the company was run by his nephew Peter John Wennerström under the name of V. Kullberg. Following Peter's death in 1935 Sanfrid Lindquist was briefly in charge, until 1940 when the firm's premises at 105 Liverpool Road, Islington were destroyed by a bomb during the Blitz of London. The Kullberg Records survive as part of the Clockmakers' Company Library held at London's Guildhall.
Later life
By 1876 it was reported that Kullberg had gone blind. In 1881 one of his timepieces won first prize in a Clockmakers Company competition, which also conferred the Freedom of the Company, an honour which he declined as it would have required him to become a naturalised British citizen. He died on 7 July 1890 at his home, 83 Tufnell Park Road, Islington, and is buried in a family grave on the west side of Highgate Cemetery. Right up to his death he was still entering his ever-improving marine chronometers into the annual Greenwich competitions and his final entry was said to be the finest instrument ever tried at the Royal Observatory, with a performance which was actually better than the Standard Clock against which it was measured.
Gallery
References
Swedish watchmakers (people)
Swedish clockmakers
People from Gotland
1824 births
1890 deaths
Burials at Highgate Cemetery
Defunct watchmaking companies
Horology | Victor Kullberg | [
"Physics"
] | 609 | [
"Spacetime",
"Horology",
"Physical quantities",
"Time"
] |
67,110,231 | https://en.wikipedia.org/wiki/Optical%20Materials%20Express | Optical Materials Express is a monthly peer-reviewed scientific journal published by Optica. It covers advances in and applications of optical materials, including but not limited to nonlinear optical materials, laser media, nanomaterials, metamaterials and biomaterials. Its editor-in-chief is Andrea Alù (City University of New York). The founding editor-in-chief was David J. Hagan.
According to the Journal Citation Reports, the journal has a 2023 impact factor of 2.8.
References
External links
Optics journals
Materials science journals
English-language journals
Monthly journals
Academic journals established in 2011
Optica (society) academic journals | Optical Materials Express | [
"Materials_science",
"Engineering"
] | 133 | [
"Materials science stubs",
"Materials science journals",
"Materials science journal stubs",
"Materials science"
] |
67,110,715 | https://en.wikipedia.org/wiki/Ammonium%20selenide | Ammonium selenide is a chemical compound with the symbol (NH4)2Se. It is claimed to be a white solid and there is little to no spectroscopic evidence on this compound.
Preparation
It was first claimed to be prepared in 1898 by reacting concentrated ammonia and hydrogen selenide gas. However, this has been disproved in 1926 as it was shown that ammonium selenide was unstable in water. Instead, ammonium selenide was produced by the reaction of anhydrous ammonia and hydrogen selenide gas (made from the reaction of iron(II) selenide and hydrochloric acid). However, there is no X-ray crystallography on this compound.
Reactions
Ammonium selenide reacts with water and various acids. For example, it reacts with nitric acid to form selenous acid. It also reacts with various metals, such as calcium, to produce their respective selenides.
References
Ammonium compounds
Selenides | Ammonium selenide | [
"Chemistry"
] | 204 | [
"Ammonium compounds",
"Salts"
] |
67,111,956 | https://en.wikipedia.org/wiki/Kimsuky | Kimsuky (also known as Velvet Chollima, Black Banshee, THALLIUM, or Emerald Sleet) is a North Korean state-backed hacker group and advanced persistent threat that targets South Korean think tanks, industry, nuclear power operators, and the South Korean Ministry of Unification for espionage purposes. In recent years Kimsuky has expanded its operations to target states such as Russia, the United States, and European nations.
History
According to the U.S. Cybersecurity and Infrastructure Security Agency Kimsuky has likely been active since 2012.
In March 2015 it was reported that South Korea claimed Kimsuky stole data from Korea Hydro & Nuclear Power.
In August 2019 it was reported that Kimsuky was targeting retired South Korean diplomats, government, and military officials, in an attack called "the first of its kind."
In September 2020 it was reported that Kimsuky attempted to hack 11 officials of the United Nations Security Council.
A lawmaker from the People Power Party reported that, in May 2021, Kimsuky was detected within the internal networks of the Korea Atomic Energy Research Institute.
See also
Lazarus Group
Ricochet Chollima
References
North Korean advanced persistent threat groups | Kimsuky | [
"Technology"
] | 243 | [
"Computer security stubs",
"Computing stubs"
] |
67,112,275 | https://en.wikipedia.org/wiki/Soft%20selective%20sweep | In genetics, when multiple copies of a beneficial mutation become established and fix together it is called soft sweep. Depending on the origin of these copies, linked variants might then be retained and emerge as haplotype structures in the population.
There are two major forms of soft sweeps:
A beneficial mutation previously separated in the population neutrally and therefore existed as multiple haplotypes at the time of the selective shift in which the mutation became beneficial. In this way, a single beneficial mutation may carry multiple haplotypes to an intermediate frequency, while itself becomes fixed.
Another model happening when multiple beneficial mutations independently occur in short succession of one another — consequently, a second copy occur through mutation before the selective fixation of the first copy.
Soft sweeps can occur from both standing variation and rapidly repeating beneficial mutations.
Overview
A selective sweep occurs when, due to strong positive natural selection, beneficial alleles quickly go to fixation in a population and results in the reduction or elimination of variation among the nucleotides near that allele. A selective sweep can occur when a rare or a formerly absent allele that improves the fitness of the carrier relative to other members of the population increases in frequency quickly due to natural selection. As the frequency of such a beneficial allele increases, genetic variants that happen to be present in the DNA neighborhood of the beneficial allele will also become more prevalent; this phenomenon called genetic hitchhiking. A Selective sweep arise if rapid changes within the frequency of a beneficial allele, driven by positive selection, distort the genealogical history of samples from the region around the selected locus. It is now recognized that not all sweeps reduce genetic variation in the same way, but rather selective sweeps can be categorized into three main categories:
The classic selective sweep or hard sweep is expected to occur when beneficial mutations are rare but when a beneficial mutation that has occurred increases in frequency rapidly, drastically reducing genetic variation in the population.
Soft sweeps from standing genetic variation (SGV) occurs when previously neutral mutations that were present in a population become beneficial because of an environmental change. Such a mutation may be present on several genomic backgrounds so that when it rapidly increases in frequency it does not erase all genetic variation in the population.
A multiple origin soft sweep happens when mutations are common, for example in a large population, so that the same or similar beneficial mutations occur on a different genomic background such that no single genomic background can hitchhike the high frequency.
Whether the selective sweep has occurred can be explored in various ways. One method is to measure linkage disequilibrium, that is whether a given haplotype is overrepresented in the population. Under neutral evolution, genetic recombination will result in the reshuffling of the different alleles within the haplotypes, and no single haplotype will dominate the population. However, during a selective sweep, selection for a positively selected gene variant will also result in hitchhiking of neighboring alleles and less opportunity for recombination. Therefore, the presence of strong linkage disequilibrium might indicate that there has been a selective sweep and can be used to identify sites recently under selection. There have been many scans for selective sweeps in humans and other species using a variety of statistical approaches and assumptions.
Differences between soft and hard sweeps
The main difference between soft and hard selective sweeps lies in the expected number of different haplotypes carrying the beneficial mutation or mutations, and therefore in the expected number of haplotypes that hitchhike to considerable frequency during the selective sweep, and which remain in the population at the time of fixation. This key difference results in different expectations in both the site frequency spectrum and in linkage disequilibrium, and consequently in the frequent test statistics based on these forms.
If hard sweeps facilitate evolutionary rescue, then just a single ancestor is responsible for the spread of the advantageous variants and so genetic diversity will be removed from the population as a consequence of adaptation as well as demographic decline. On the other hand, a soft sweep, in which the beneficial allele is independently derived in multiple ancestors, will keep certain ancestral diversity that existed prior to the environmental shift that initiated the fitness changes.
Detecting soft sweeps
Is there any way to separate soft and hard sweeps? Obviously, only recent adaptive events leave a measurable signal at all (hard or soft). Signals from the site frequency spectrum (like the excess of rare alleles that is picked up by Tajima 1989) usually fade on time scales of ~ 0.1Ne generations, while signals based on linkage disequilibrium or haplotype statistics only last ~ 0.01Ne generations. To find it easily, selection must be strong (4NeSb≫100). Even then, soft sweeps can be difficult to discriminate from neutrality if they are ‘super soft’, i.e., if there are numerous independent origins of the beneficial allele, or if its starting frequency in the SGV is high.
For a strong interpretation of selection versus neutrality, we need a test statistic with reliably high power for hard and soft sweeps. Based on above-described patterns, and as exhibited, tests based on the site frequency spectrum (looking for low- or high-frequency derived alleles) have low power to reveal soft sweeps, whereas haplotype tests can detect both types of sweeps. In contrast to single-origin soft sweeps (which always leave a weaker footprint), the capability to detect multiple-origin soft sweeps can be higher than the capability to detect completed hard sweeps due to the clear haplotype structure right at the selected site.
Detecting soft sweeps with a single origin is difficult. Some studies and tests based on a combination of summary statistics have been developed by Peter, Huerta-Sanchez & Nielsen (2012) and by Schrider & Kern (2016). Both tests have reliable power to find soft sweeps for robust selection and a high starting frequency (5–20%) of the selected allele. In addition, well-defined practical instances typically rely on other indications, go with footprint: e.g., a source population is recognized with the selected allele in the SGV (e.g., marine and freshwater sticklebacks, or identified and very recent selection pressure does not leave enough time for the allele to increase from a single copy to the frequency observed today (for example CCR5 adaptation to HIV in humans). On the whole, soft sweeps with multiple origins have better chances to be detected.
See also
Selective sweep
References
Population genetics
Selection | Soft selective sweep | [
"Biology"
] | 1,331 | [
"Evolutionary processes",
"Selection"
] |
67,112,408 | https://en.wikipedia.org/wiki/Empowerment%20%28artificial%20intelligence%29 | Empowerment in the field of artificial intelligence formalises and quantifies (via information theory) the potential an agent perceives that it has to influence its environment. An agent which follows an empowerment maximising policy, acts to maximise future options (typically up to some limited horizon). Empowerment can be used as a (pseudo) utility function that depends only on information gathered from the local environment to guide action, rather than seeking an externally imposed goal, thus is a form of intrinsic motivation.
The empowerment formalism depends on a probabilistic model commonly used in artificial intelligence. An autonomous agent operates in the world by taking in sensory information and acting to change its state, or that of the environment, in a cycle of perceiving and acting known as the perception-action loop. Agent state and actions are modelled by random variables () and time (). The choice of action depends on the current state, and the future state depends on the choice of action, thus the perception-action loop unrolled in time forms a causal bayesian network.
Definition
Empowerment () is defined as the channel capacity () of the actuation channel of the agent, and is formalised as the maximal possible information flow between the actions of the agent and the effect of those actions some time later. Empowerment can be thought of as the future potential of the agent to affect its environment, as measured by its sensors.
In a discrete time model, Empowerment can be computed for a given number of cycles into the future, which is referred to in the literature as 'n-step' empowerment.
The unit of empowerment depends on the logarithm base. Base 2 is commonly used in which case the unit is bits.
Contextual Empowerment
In general the choice of action (action distribution) that maximises empowerment varies from state to state. Knowing the empowerment of an agent in a specific state is useful, for example to construct an empowerment maximising policy. State-specific empowerment can be found using the more general formalism for 'contextual empowerment'. is a random variable describing the context (e.g. state).
Application
Empowerment maximisation can be used as a pseudo-utility function to enable agents to exhibit intelligent behaviour without requiring the definition of external goals, for example balancing a pole in a cart-pole balancing scenario where no indication of the task is provided to the agent.
Empowerment has been applied in studies of collective behaviour and in continuous domains. As is the case with Bayesian methods in general, computation of empowerment becomes computationally expensive as the number of actions and time horizon extends, but approaches to improve efficiency have led to usage in real-time control. Empowerment has been used for intrinsically motivated reinforcement learning agents playing video games, and in the control of underwater vehicles.
References
Artificial intelligence
Cognitive science
Robotics engineering | Empowerment (artificial intelligence) | [
"Technology",
"Engineering"
] | 566 | [
"Computer engineering",
"Robotics engineering"
] |
67,112,665 | https://en.wikipedia.org/wiki/Lenacapavir | Lenacapavir, sold under the brand name Sunlenca, is an antiretroviral medication used to treat HIV/AIDS. It is taken by mouth or by subcutaneous injection.
The most common side effects include reactions at the injection site and nausea.
Lenacapavir was approved for medical treatment in the European Union in August 2022, in Canada in November 2022, and in the United States in December 2022. It is the first of a class of drugs called capsid inhibitors to be approved by the US Food and Drug Administration (FDA) for treating HIV/AIDS.
Medical uses
Lenacapavir, in combination with other antiretrovirals, is indicated for the treatment of HIV/AIDS. It is used in heavily treatment-experienced adults with multiple drug resistance in whom current antiretroviral therapy is ineffective due to resistance, intolerance or safety considerations. It has also been found to be highly effective as HIV pre-exposure prophylaxis (PrEP) in heterosexual women in Africa. Further studies are ongoing assessing effectiveness in men who have sex with men and people who inject drugs.
Mechanism of action
Lenacapavir works by binding directly to the interface between HIV-1 viral capsid protein (p24) subunits in capsid hexamers, interfering with essential steps of viral replication, including capsid-mediated nuclear uptake of HIV-1 proviral DNA, virus assembly and release, production of capsid protein subunits, and capsid core formation. The US Food and Drug Administration considers it to be a first-in-class medication.
History
Lenacapavir was developed by Gilead Sciences.
The safety and efficacy of lenacapavir were established through a multicenter clinical trial with 72 participants whose HIV infections were resistant to multiple classes of HIV medications. These participants had to have high levels of virus in their blood despite being on antiretroviral drugs. Participants were enrolled into one of two study groups. One group was randomized to receive either lenacapavir or placebo in a double-blind fashion, and the other group received open-label lenacapavir. The primary measure of efficacy was the proportion of participants in the randomized study group who achieved a certain level of reduction in virus during the initial 14 days compared to baseline.
The US Food and Drug Administration granted the application for lenacapavir priority review, fast track, and breakthrough therapy designations.
In 2024, Science named lenacapavir "2024 Breakthrough of the Year", citing its "astonishing 100% efficacy" in one large efficacy trial in women and "99.9% efficacy in gender diverse people who have sex with men," while highlighting that research providing a "new understanding of the structure and function of HIV’s capsid protein" led to the drug's "off-the-charts success".
Society and culture
Legal status
In June 2022, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Sunlenca, intended for the treatment of adults with multidrug‑resistant human immunodeficiency virus type 1 (HIV‑1) infection. The applicant for this medicinal product is Gilead Sciences Ireland UC.
Lenacapavir was approved for medical use in the European Union in August 2022, in Canada in November 2022, and in the United States in December 2022.
Economics
the drug, produced by Gilead, costs for the first year. A study presented in July 2024 found that mass production of a generic version would allow a profit margin of 30% on an annual price of $40 if used by 10 million people. The authors said that lowering HIV levels significantly would probably require 60 million people to take the drug preventatively.
Research
As of 2021, it is in phase II/III clinical trials. It is being investigated as a treatment for HIV patients infected with multidrug-resistant virus and as a twice-yearly injectable for pre-exposure prophylaxis.
Studies have been conducted for the use of lenacapavir in treatment-naive individuals. For virally suppressed individuals switching treatment, early studies have tested lenacapavir injections in combination with infusions of the broadly neutralizing antibodies teropavimab and zinlirvimab as well as lenacapavir with islatravir.
A phase 3 clinical trial study examined efficacy for pre-exposure HIV prevention (PrEP). It found an incidence rate ratio of 0.00 (as no cases occurred in the lenacapavir group) with a 95% confidence interval of 0.00-0.04 with p<.001. Injection site reactions led to discontinuation by 0.2% of lenacapavir patients
Another lenacapavir phase III study, examined the incidence compared to the background rate for men persons. It found an incidence rate ratio of 0.04 with a 95% confidence interval of 0.01 to 0.18, at p<.001. Injection site reactions led to discontinuation by 1.2% of patients.
References
External links
Amides
Antiretroviral drugs
Chloroarenes
Cyclopropanes
Fluoroarenes
Gilead Sciences
Indazoles
Orphan drugs
Pyridines
Sulfonamides
Trifluoromethyl compounds | Lenacapavir | [
"Chemistry"
] | 1,107 | [
"Amides",
"Functional groups"
] |
67,113,375 | https://en.wikipedia.org/wiki/RY%20Tauri | RY Tauri is a young T Tauri star in the constellation of Taurus about away, belonging to the Taurus Molecular Cloud. It is more massive than typical T Tauri stars, and may be an intermediate between this class and the Herbig Ae/Be star type.
Stellar system
There was one suspected stellar companion to RY Tauri, a 14.81 magnitude object 2MASS J04215810+2826300 discovered in 2008 at a projected separation of 1500 AU. It was proven to be a background star not related to RY Tauri with Gaia data though.
Protoplanetary system
The star is surrounded by a protoplanetary disk discovered in 2006. The disk is massive at 0.3 and consists mostly of gas. The existence of a protoplanetary disk is disputed; the signal can also be attributed to the birth envelope partially disrupted by the young star. Also, polar jets were detected. The jets contain detectable amounts of oxygen and sulfur.
A superjovian planet on a 0.2 AU orbit is suspected since 2021.
Variability
RY Tauri varies in brightness. It is a highly (by 1.5 magnitudes) obscured Orion variable, producing fluctuations of brightness as the star shines through the inhomogeneities of the inner part of the protoplanetary disk. It also produces irregular brightening events with a duration of about a month and amplitude of one magnitude.
The light curve of RY Tauri varies by 2-3 magnitudes over a decade and by roughly one magnitude over a year. The star was gradually brightening during the 20th century, possibly changing the variability mechanism in the process.
References
T Tauri stars
Circumstellar disks
Taurus (constellation)
283571
BD+28 645
020387
J04215740+2826355
Tauri, RY
Hypothetical planetary systems | RY Tauri | [
"Astronomy"
] | 381 | [
"Taurus (constellation)",
"Constellations"
] |
67,113,577 | https://en.wikipedia.org/wiki/Samsung%20Galaxy%20A52 | The Samsung Galaxy A52 is a mid-range Android-based smartphone developed and manufactured by Samsung Electronics as a part of its Galaxy A series. The phone was announced on 17 March 2021 at Samsung's virtual Awesome Unpacked event alongside the Galaxy A72.
It serves as the successor of the Galaxy A51. It is similar to its predecessor, but features an upgraded 64 MP main camera, an increased-capacity 4500 mAh battery, and IP67 water and dust resistance.
An upgraded device, Galaxy A52s, was first released in August 2021 with a different chipset (Qualcomm Snapdragon 778G), Wi-Fi 6 support and a new device color (Awesome Mint).
Specifications
Design
Galaxy A52 has a similar design with its predecessor Galaxy A51. It has an Infinity-O display with a cutout for the selfie camera and slim bezels just like the A51. Unlike the A51, A52 has matte color options rather than glossy gradient finishes.
The display is protected by Corning Gorilla Glass 5 while the frame and back panel is made of plastic. Both 4G and 5G variants share the identical design. It is available with Awesome Black, Awesome White, Awesome Violet, Awesome Blue options. Both variants have IP67 water and dust resistance.
Hardware
The Galaxy A52 is powered by Qualcomm Snapdragon 720G SoC with 8 nm process, an octa-core CPU and Adreno 618 GPU. The Galaxy A52 5G is, on the other hand, powered by Qualcomm Snapdragon 750G SoC with 8 nm process, an octa-core CPU and Adreno 619 GPU. The Galaxy A52s received a Qualcomm SM7325 Snapdragon 778G 5G with 6 nm process, an Octa-core CPU (4x2.4 GHz Kryo 670 & 4x1.9 GHz Kryo 670) and an Adreno 642L GPU.
Display
Both A52 and A52 5G feature 6.5 inch Super AMOLED display with 800 nits maximum brightness, 20:9 aspect ratio, 1080x2400 pixels resolution, 411 ppi pixel density and ~84.1% screen-body ratio; however, the display on the A52 has 90 Hz refresh rate and the display on the A52 5G has 120 Hz refresh rate.
Cameras
Both 4G and 5G variants have a quad rear camera setup with a 64 MP main camera with optical image stabilization (OIS), a 12 MP ultrawide angle camera, a 5 MP depth camera and a 5 MP depth sensor. The camera is able to take video up to 4K@30fps, and 1080p@60fps.
Battery
Both 4G and 5G variants have a 4500 mAh batteries with 25W fast charging support; however, there is a 15W charger in the box and users need to buy the 25W charger separately.
Memory
The 52 comes in storage configurations of 128Gb storage / 4Gb RAM, 128/6, 128/8, 256/6, and 256/8.
The 52 5G comes in 128/6, 128/8, and 256/8.
The 52s 5G comes in 128/4, 128/6, 128/8, 256/6, and 256/8.
Features
The device mounts a 3.5mm Audio jack and uses the top earpieces, with the bottom speaker, to deliver stereo sound. It also features an under the screen, optical fingerprint scanner.
Software
Both 4G and 5G variants are shipped with Android 11 and Samsung's proprietary user interface One UI 3.1. Samsung stated that both 4G and 5G variants will get 3 OS version updates, 3 years of monthly updates and 4 years of security updates. As of January 2025, the A52 series has already received an update to Android 14 and One UI 6.1. After that, the A52 series will no longer receive software updates from Samsung.
References
Samsung Galaxy
Mobile phones introduced in 2021
Android (operating system) devices
Samsung mobile phones
Phablets
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Discontinued Samsung Galaxy smartphones | Samsung Galaxy A52 | [
"Technology"
] | 885 | [
"Crossover devices",
"Phablets"
] |
67,113,672 | https://en.wikipedia.org/wiki/Samsung%20Galaxy%20A72 | The Samsung Galaxy A72 is a mid-high range Android-based smartphone developed and manufactured by Samsung Electronics. The phone, announced alongside the Galaxy A52 at Samsung's virtual Awesome Unpacked event on 17 March 2021, serves as the successor to the Galaxy A71. The Galaxy A72 retains many of the features its previous iteration, but also includes an upgraded 5,000 mAh battery, IP67 water and dust resistance, and the inclusion of an 8 MP telephoto camera.
Specifications
Design
Galaxy A72 has a similar design with its predecessor. It has a Infinity-O display with a cutout for the front-facing camera just like the Galaxy A71. However, the device has matte color options rather than the glossy gradient finishes on the Galaxy A71. It is available with Awesome Black, Awesome White, Awesome Violet and Awesome Blue color options. The display is protected by Corning Gorilla Glass 3 while the frame and back panel is made of plastic. It has IP67 water and dust resistance.
Hardware
Galaxy A72 is powered by Qualcomm Snapdragon 720G SoC with 8 nm process, an octa-core CPU comprising a high performance cluster with 2x 2.3 GHz Kryo 465 Gold cores and a high efficiency cluster with 6x 1.8 GHz Kryo 465 Silver cores and Adreno 618 GPU, and paired with 6 or 8 GB RAM and 128 GB internal storage. The SoC powering the Galaxy A72 is slightly better in single core CPU benchmarks than the SoC of the predecessor Galaxy A71, Qualcomm Snapdragon 730G (one of the chipset versions of Galaxy A71) and Qualcomm Snapdragon 730 (original chipset of Galaxy A71).
Galaxy A72 has a 6.7 inch Super AMOLED display with 800 nits maximum brightness, 20:9 aspect ratio, 1080x2400 resolution, ~393 ppi pixel density and 90 Hz refresh rate. The display also has a punch hole for the front-facing camera.
Galaxy A72 has a quad rear camera setup with a 64 MP main camera with optical image stabilization (OIS), a 12 MP wide-angle camera, an 8 MP telephoto camera with optical image stabilization and 3x optical (lossless) zoom and a 5 MP macro. The phone is capable of zooming up to 30x and has a 32 MP front-facing camera. The rear camera setup also includes an LED flash.
Galaxy A72 has Bluetooth 5.0, Wi-Fi 802.11 a/b/g/n/ac, a 3.5mm headphone jack, and NFC. It has a 5000 mAh non-removable battery with 25W fast charging support. There is a 25W charger in the box unlike the Galaxy A52 shipping with a 15W charger.
Galaxy A72 has stereo speakers, an under-display fingerprint sensor and a hybrid Dual-SIM slot (Nano-SIM/MicroSD card combo).
Software
Android 11 out of the box with One UI 3/3.1
Can be upgraded to Android 15 with One UI 7.0
Will get security updates. Security updates, however, are not monthly updates as it used to be for A71 or is for A52. It is currently in the bi-annually update schedule of Samsung Security Website.
References
Samsung Galaxy
Mobile phones introduced in 2021
Android (operating system) devices
Samsung mobile phones
Phablets
Mobile phones with multiple rear cameras
Mobile phones with 4K video recording
Discontinued Samsung Galaxy smartphones | Samsung Galaxy A72 | [
"Technology"
] | 754 | [
"Crossover devices",
"Phablets"
] |
67,114,934 | https://en.wikipedia.org/wiki/Inca%20complex%20at%20P%C3%ADsac | The Inca complex at Pisac is a large Incan complex of agricultural terraces, residences, guard posts, watchtowers and a ceremonial/religious centre located along a mountain ridge above the modern town of Pisac in the Sacred Valley of Peru. In 1983 the Pisac National Archeological Park was established to recognize the importance of and to protect the remains of the complex.
History
The remains of Lucre and Killke pottery that have been found in the area, suggest that the location has been occupied for some time.
An early settlement which probably pre-dated the Inca existed on the hillside between the Quitamayo and Chongo tributaries of the Vilcanota river. The community raised their crops on terraces as well as on the flood plain. Later as the threats from other tribes declined the villagers moved closer to the main road to Cusco and Urcos.
It is unknown when the complex that remains today was built, but the consensus is that the contributions by the Inca's were built by the Inca emperor Pachacuti (1438–1471/1472) no earlier than 1440.
Despite the excellent condition of many of the structures, little is conclusively known about the site's actual purpose. Some researchers believe that while Choquequirao defended the western entrance, and Ollantaytambo the northern, Pisac defended the southern entrance to the Sacred Valley. Its location controlled a route which connected the Inca Empire with the border of the rain forest and so could protect Cusco from possible attacks by the Antis (a collective Inca term for the many varied fierce ethnic groups such as the Asháninka and Tsimané) who lived in the Antisuyu region (the eastern part of the Inca empire), present day Pachacutec and the Manu jungle.
The site was certainly an observatory and religious site, and although it was reinforced with the ramparts of a massive citadel, the Incas never retreated here to defend their empire against the Spaniards. When Manco Inca rebelled against the Spanish in 1534, he took up a position first at Calco, 18 km (11 miles) farther downstream, before retreating to Ollantaytambo. This indicates that he considered Pisac to have been simply too close to Cusco.
Today the consensus among many scholars (among them Kim MacQuarrie) is that Pachacuti constructed it as multi-purpose residence, citadel, observatory and religious site. In this role it would support his panaca (family and descendants), provide a secluded royal retreat located well away from Cusco where he and the nobility could relax between military campaigns, undertake ritual and religious ceremonies, serve as a refuge in times of danger as well as commemorating his victories over the Cuyos.
In addition to Pisac the other royal estates that Pachacuti is considered to have established were Ollantaytambo and Machu Picchu (conquest of the Vilcabamba Valley). The Cuyos had been implicated in a conspiracy to kill Pachacuti, which was put down so ruthlessly that most of the Cuyos were killed.
Despite its size and proximity to Cusco the Inca complex is not mentioned by any of the Spanish chroniclers.
The modern town of Písac was built in the valley below the ruins of the Inca complex by Viceroy Toledo during the 1570s.
The first modern description of the Inca complex occurred in the late 19th century when Ephraim George Squier (1821-1888), the US Commissioner to Peru visited Pisac and left a detailed description of the Inca ruins in his 1877 book Peru - Incidents of Travel and Exploration in the Land of the Incas. In his book Squier offered the following introduction to the complex:
Squier's book did much to bring the complex to the attention of the English-speaking world. The Austrian-French scientist-explorer, Charles Wiener (1851-1919) also visited Písac and wrote an account of his explorations in Perou et Bolivie (Paris, 1880).
On 12 February 2016, 10-year old Valeria Arlette Garcia Escobar was killed by a rock fall while exploring the complex with her Peruvian family. It is believed that heavy rains the night before, coupled with strong sunshine may have loosened the rocks. Two other family members were injured. The area of the accident was not near any Inca structures and lead to the closing of the Pisaq Archaeological Parks until 1 September 2016 following repairs.
Celebrations are held annually on 24 August at the complex in honour of Willka Raymi.
Establishment of the archaeological park
The site was first protected when in response to the inclusion of Machu Picchu and Cusco on the UNESCO World Heritage List Law 23765 was drawn up, declaring the archaeological parks of Ollantaytambo, Písac, Piquillaqta and Tipon and other archaeological sites in the Sacred Valley part of the cultural heritage of the nation. The law was unanimously approved by the Legislative Chambers meeting on 15 December 1983 and promulgated by the Executive on 30 December of that year. The area that the Písac archaeological park covered was subsequently defined on 17 May 2002 by National Directive Resolution No. 429-2002.
The park covers 9,063 hectares.
Description
Located at the entrance to the Sacred Valley the Incan the complex stretches at varying elevations between 3,446 m and 3,514 metres above sea level for approximately one kilometre along a mountain ridge sandwiched between the Kitamayu River (to the west) and the Chongo River (to the east), which are tributaries of the Vilcanota.
The complex is divided into seven architectural areas (from north to south) - Qantus Raqay, Qallaq'asa, Inca Qonqorina, Intiwatana, P'isaqa, Hospitalniyoc and Kanchis Racay. These are separated by natural terrain but accessible by narrow paths wind tortuously along the ridge and in two places passing through two tunnels with running water supplied by canals. Almost all the original names of the different areas of the complex are lost; the names that are known today were established by tradition, historians and archaeologists.
The first part of the complex reached by visitors coming by motor vehicle is Qanchus Racay in the north-eastern corner of the complex. South of Qanchus Racay is the first of the numerous terraces (andenes) while on a plateau to the west beside the Kitamayu River is a bath complex containing four purification baths.
On the opposite bank of the Kitamayu River on an irregular almost vertical mountain slope is the T'antana Marka, which is home to the looted tombs of the biggest pre-Hispanic cemetery in the region.
Southwards of the bath complex on the steep slopes of a hill is the Qallaq'asa, a residential area which contains homes and storehouses. According to some sources this is also known as Hanam P'isaq (Upper Písac).
From this point there are three routes south. One continues along a path along the western side of the ridge above the Kitamayu River to the Tianayoc from which via a 3-metre long tunnel is reached the Inca Qonqorina, which is an administration area. Below it is the complex's ceremonial-religious area whose main feature is the Intiwatana (in Qechua, the tie of the sun, also known as an Intihuatana).
The second route drops down the eastern slope to the base of the Qallaq'asa and then continues southwards across the hillside and through a trapezoidal doorway called Amaru Punku (serpent gate, Qechua etymology) in a partial wall and then via a 16-metre long tunnel hollowed from the rock to connect with the path leading from the Tianayoc to the Intiwatana. The third path descends further down the southern side of the large terrace and then passes through a doorway with no lintel before heading southwards around the eastern side hillside to where the path branches either up to the Intiwatana or straight to the P'isaqa area.
From the Intiwatana a path beginning at its southeast corner drops down to the P'isaqa area that has a somewhat semi-circular shape following the mountain's silhouette. From the P'isaqa area there is also a path that descends partly down the hillside to the Kanchis Racay area, which consists of only a couple of structures.
From the Intiwatana a path runs southwards along the top of the ridge to watch towers (pucaras) in the Coriwayrachina area and storehouses (qullqas) in the Hospitalniyoc area. The path then descends through an area of steep terracing that reaches as far as the edge of precipices to merge with a path from P'isaqa. From this junction the path crosses over the ridge crest and descends though more agricultural terraces, filling the narrow valley of the Kitamayu River to eventually connect with a wide stone path that goes to the town.
If the lowest terraces on which Patapatayoc and the town of Písac are located are included then the entire complex covers 65.5 hectares. If only the terraces and buildings that cover the upper part, then the size of the complex reduces to 24 hectares, of which the seven architectural complexes occupy a total of 4.3 hectares.
Bridges
The site is home to several suspension bridges. One was at Paccháyoc where the bases still exist. And the other was located on the western side of the Intiwatana area.
Coriwayrachina Area
This area whose name means "gold sifter" is on the ridge south of the Intiwatana is home to several towers (Pucaras) used for communication or observation and some very steep terraces probably used for defense.
Hospitalniyoc Area
On the eastern slope below the Coriwayrachina in what is known as the Hospitalniyoc area are six storehouses (qullqas, also spelt as colca, collca, qolca, qollca, qollqa) of equal size and constructed of adobe. Qullqas were often built in groups or blocks and could be rectangular (as at Písac) or round, but all had only a single room. They are often situated on hillsides and located so that they are mostly in the shade, while the higher altitude ensured that they had good ventilation and lower temperatures, which protected their perishable contents against decay. Under-flooring and drainage canals were additional aids in keeping the interior atmosphere dry and allowed for the storage of goods such as grain and potatoes for two years or more.
Inca Qonqorina area
This is an administration area on the ridge just above the Intiwatana.
Intiwatana area
Located on a small ridge with panoramic views on both sides, is the complex's ceremonial and religious area, which is generally referred to as the Intiwatana or Intihuatana area due to the presence in its centre of an Intiwatana. This is a carved ritual rock whose name is taken to mean "hitching-post of the Sun" in English. Intihuatana is a Hispanicized spelling of the Quechua word Intiwatana which means inti (sun), watana (fastener).
The Intiwatana is housed in a semi-circular building similar to the letter "D", with one lateral straight wall which main gate is toward the south is built of perfectly fitted blocks of the finest pink granite. It is believed to have been used as an astronomical observatory to track the sun's movements in particular to determine the arrival of important growing seasons. On 21 June, the sun rises precisely above the peak to the east and above another on the 21 December.
The carved rock was damaged by the Spanish who wanted to wipe out the indigenous belief system. This section is now closed to the public, due to vandals who destroyed part of it a few years ago.
The building housing the Intiwatana is surrounded by five other buildings, one of which is believed to have been devoted to worship of the moon. In front of the Intiwatana is a sacred chakana (Inca cross). There are also several ceremonial baths which discharge into an underground canal.
The walls of five other temples surround the Intiwatana, including one that was probably devoted to worship of the moon. In front of the Intiwatana is a sacred chacana (Inca cross).
Pisaq'a
Located 200 metres and directly below the Intiwatana on a large semi-circular ledge is this residential area of 30 or so buildings. As well as its own baths it has finer brick work than the other residential areas, indicating that it was the home of the elite.
Protective wall
A large wall built of large dressed stones pierced by four gateways, protects the northern base of the Qallaq'asa area. The only one that still retains its lintel is on a path that leads to southwards to the Intiwatana and the elite residential area of P'isaqa. It is known by the name of Amaru Punku, which comes from the Quechua words amaru (snake), and punk (doorway) hence the common English translation of "door of the serpent". The hinges are still visible.
Qallaq'asa area
The name of the Qallaq'asa residential area which is above sea level comes from the Quechua words q'alla (cut) and q'asa (pass), in reference to a tunnel that connects it with the Intiwatana.
Cascading down the side of the hill its 23 buildings are built from rough field stone, stuck together with adobe, indicating that they were probably inhabited by lower-status workers.
Qantus Raqay (Qanchis Racay) area
Located 3,446 m above sea level on the edge of a precipice Qantus Raqay (from the Quechua words qanchus (seven) and raqay (enclosure)) is also known as "Kanturaqay". One of three residential areas in the complex and spreading over three levels it consists of rough stone buildings with pirka type walls made with non-carved mud bonded small and medium-sized stones. The walls were originally had a clay stucco applied overtop, indicating that they were probably inhabited by those of a lower-status. From its position overlooking the road toward the Paucartambo region and the Antisuyo and controlling the northeastern corner of the complex it probably served as the home of the military garrison or as a shelter for local villagers in times of war.
T'antana Marka
Opposite the Inca baths on the other side of the gully down which the Kitamayu River flows are tombs cut into the steep cliff face of the adjacent mountain. This was one of the largest cemeteries in the pre-Columbian world, with more than 3,500 tombs in various states of destruction, though some sources claim as many as 10,000 tombs. Its name comes from tankay (to push) and marka (place), which can be translated as launch site. The Incas believed in reincarnation, so the kept their mummies buried in the fetal position with all their belongings and food needed for their new life. After the arrival of the Spaniards, huaqueros (grave robbers) did not hesitate to desecrate the graves and plunder the jewels, metals and precious stones. Today only small holes remain as a result of the desecration.
Terraces
The mountain spur is covered with approximately 500 agricultural terraces called andenes, some high in places, which follow the contours of the hillside. While they reduced the threat of soil erosion from landslides their primary purpose was to expand the amount of arable land. The terraces are contained by walls of field stones roughly to fit one another, typically 600 to 750 mm (23 to 30 inches) thick.
As well as creating a level planting area and retaining humidity, the stone retaining walls heat up during the day and slowly release that heat to the soil as temperatures plunge at night, keeping sensitive plant roots warm during frosts and thus expanding the growing season. They also allowed the growing of crops at higher attitudes, with studies having found that the ambient temperature of terraced areas being 3 °C higher than that of unterraced hillsides and a downshift in elevation of approximately . The use of gravel to backfill the lower levels of the terraces conserves water and yet ensures that following heavy rains the water drains and doesn't build inside which would cause the soil to expand and push out the wall.
There are at least 14 different shapes of terrace at heights from to metres above sea level. Many are still in use today.
The terraces closest to modern Písac are the Andenes Acchapata, which consist of up of 40 individual terraces which extend down to the valley floor and the river.
Tianayuc
This is a seat near the Inca Qonqorina area cut out of a single rock with room for two people. Hence the name Tianayuc that means "it has seat".
There are also the remains of a tower that once dominated this part of the Kitamayu gorge.
Towers
The complex is home to more than 20 towers (called Pucaras, which can be divided into two types: Habitaculo towers and Atalaya towers; the first have a conical shape with well carved jointed stones and are connected to water channels. The Atalaya towers are almost conical and appear to have been used as watchtowers. The most important are in the Coriwayrachina area, where they guard the path up from up from the present-day town of Písac. Below the towers are terraces (andenes).
Tunnels
On the eastern slope of the ridge on a path that connects the bottom area of the Qallaq'asa with the Intiwatana the Inca engineers enlarged a natural fissure in the rock to create a long tunnel through the entire cliff. The teardrop-shaped slit is just wide enough for one person to traverse single file and would have served as an excellent defensive location.
From the Qallaq'asa a path runs along the upper part of the ridge via the Tianayuc and through a three-metre long tunnel to the Intiwatana.
Water supplies
The complex has at least five water supply channels, more than two irrigation channels, more than three agricultural drainage channels, but no domestic wastewater drainage.
Water is collected from a small lake above sea level and conveyed via a canal to four purification baths near the river on the flat area between the Qanchus Racay and Qallaq'asa before passing along another canal to supply the Qanchus Racay area.
Another source of water is a spring on the left bank of the Kitamayu River, which is collected in a basin and then conveyed in a canal that runs along the foot of the T'antana Marka and which then crosses the river via the long high Antachara aqueduct to the other side where it passes via along the cliff face via another long by high aqueduct (held aloft on three large pillars) and then in a canal all the way to the ceremonial-religious area surrounding the Intiwatana. The name Antachaca comes from the Quechua words anta (cooper) and chaka (bridge). From the Inca Qonqorina area a small canal running down the hillside discharges via fountains in to the main canal bring water from the Antachara to the Intiwatana area.
From the Intiwatana area another channel drops down towards the P'isaqa area.
Gallery
See also
Ichhunayuq
Machu Kuntur Sinqa
Willka Raymi
References
Further reading
External links
Andenerías prehispánicas y gestión de riesgos. Análisis de su puesta en valor como factor de desarrollo cultural, Pisac – cusco (Pre-Hispanic andenerías and risk management. Analysis of its value as a development factor Cultural, Pisac – Cusco). In Spanish.
Detailed photo gallery of the Pisac ruins
Exploring the History Behind the Pisac Ruins
Overview of the Inca complex at Pisac
Pisaq Inca Ruins, a Photo Gallery
Pisac Archaeological Site
Localización de la Actividad In Spanish.
15th-century establishments in the Inca civilization
Archaeoastronomy
Archaeological sites in Peru
Archaeological sites in Cusco Region
Buildings and structures completed in the 15th century
Former populated places in Peru
Historic Civil Engineering Landmarks
Inca
Populated places established in the 1450s
Protected areas established in 1983
Ruins in Peru
Tourist attractions in Cusco Region | Inca complex at Písac | [
"Astronomy",
"Engineering"
] | 4,274 | [
"Civil engineering",
"Archaeoastronomy",
"Astronomical sub-disciplines",
"Historic Civil Engineering Landmarks"
] |
67,117,288 | https://en.wikipedia.org/wiki/Pick%20glass | A pick glass also known as a piece glass is a magnifying glass helpful in counting thread count. It is used to determine the number of yarns in warp and weft in woven fabrics and courses and wales in knitted fabrics. Compact constructions of fabrics may have a higher thread count. That is also called "cloth count."
Function
Pick glass aid in measuring the following.
Ends and picks
Ends per inch is the number of warp threads per inch of woven fabric.
Picks per inch is the number of weft threads per inch of woven fabric. Pick is a term that refers to a single weft thread. By and large, the more ends and picks per inch, the finer the cloth. Balanced plain weave fabrics have warp and weft threads that are the same weight (size) and have the same number of ends and picks per inch.
Courses and Wales
Loops are the building blocks of knitted fabrics, and courses and wales in knitted fabrics are importantly similar to ends and pick in woven fabrics. The knitting structure is formed by intermeshing the loops in consecutive rows.
Courses: are the total number of horizontal rows measured in per inch or per centimetre. The course is a horizontal row of loops formed by all the adjacent needles during one revolution. course length is obtained by multiplying loop length with the number of needles involved in the production of the course.
Wales: are the number of vertical columns measured in per inch or per centimetre.
See also
Fabric inspection
Linen tester
References
Bibliography
Textiles
Magnifiers | Pick glass | [
"Technology",
"Engineering"
] | 312 | [
"Magnifiers",
"Measuring instruments"
] |
67,118,588 | https://en.wikipedia.org/wiki/Northern%20resident%20orcas | Northern resident orcas, also known as northern resident killer whales (NRKW), are one of four separate, non-interbreeding communities of the exclusively fish-eating ecotype of orca in the northeast portion of the North Pacific Ocean. They live primarily off the coast of British Columbia (BC), Canada, and also travel to southeastern Alaska and northern Washington state in the United States. The northern resident population consists of three clans (A, G, R) that consists of several pods with one or more matrilines within each pod. The northern residents are genetically distinct from the southern resident orcas and their calls are also quite distinct.
Social structure
Like the Southern residents, the Northern residents live in groups of matrilines. A typical Northern resident matriline group consists of an elder female, her offspring, and the offspring of her daughters. Both males and female orcas remain within their natal matriline for life. Matrilines have a tendency to split apart over time. Pods consists of related matrilines that tend to travel, forage, socialize, and rest together. Each pod has a unique dialect of acoustic calls. Pods that share one or more certain calls belong to a common clan.
Behaviours
In the summer months the Northern residents can often be observed swimming close to shores of Johnstone Strait and positioning their stomachs to rub themselves on beach pebbles. More than 90% of the Northern resident population observed in Johnstone Strait visit these rubbing beaches. They emit certain and specific calls more frequently while engaging in this activity. Although it is not clear why they engage in this activity, beach rubbing has been identified as an important activity to the culture of the entire Northern resident community. This behaviour was originally thought to be unique to the Northern resident community; however, the Southern Alaska resident killer whales have also been observed beach rubbing.
Location
The Northern residents have been seen as far south as Grays Harbor, Washington and as far north as Glacier Bay, Alaska. From spring until mid-summer, the Northern residents are commonly found in Chatham Sound near the BC–Alaska ocean border and in Caamaño Sound between Haida Gwaii and the BC mainland. From June until October, they are commonly found in Johnstone Strait. The habitat of the Northern residents overlaps with the Southern residents; however, the two types of orcas have never been observed together.
Members of A clan have been the most commonly sighted whales off northeastern Vancouver Island, whereas G clan is most commonly sighted off the west coast of Vancouver Island, and members of R clan are most commonly sighted in the northern parts of the community's range.
Conservation efforts
In 2008, the Canadian Ministry of Oceans and Fisheries designated the waters of Johnstone Strait and southeastern Queen Charlotte Strait as critical habitat and legally protected under a Critical Habitat Order.
In 2018, the western part of the Dixon Entrance along the north coast of Graham Island from Langara Island to Rose Spit was also identified as critical habitat for the Northern residents.
List of pods
This is a list of northern resident orca pods that live off the coast of British Columbia, Canada, as of March 2013.
Asterisk indicates deceased member.
References
Further reading
Orcas
Endemic fauna of the Pacific Northwest
Marine biology
Cetaceans of the Pacific Ocean | Northern resident orcas | [
"Biology"
] | 659 | [
"Marine biology"
] |
67,119,878 | https://en.wikipedia.org/wiki/Mar%C3%ADa%20Gloria%20Dom%C3%ADnguez-Bello | María Gloria Domínguez-Bello (born December 3, 1959) is a Venezuelan-American microbial ecologist that has worked on adaptations of gut fermentation organs in animals, gastric colonization by bacteria, assembly of the microbiota in early life, effect of practices that reduce microbiota transmission and colonization in humans, and effect of urbanization. She is the Henry Rutgers Professor of Microbiome and Health at Rutgers University, New Brunswick. Her lab at collaborates in multidisciplinary science, integrating microbiology, immunology, pediatrics, nutrition, anthropology, environmental engineering and architecture/urban studies, and microbial ecology.
Education and career
María Gloria Domínguez-Bello was born in Caracas, Venezuela on 3 December 1959. She went to University Simon Bolivar, where she received her B.S. in Biology in 1983. Domínguez-Bello then attended the University of Aberdeen in Scotland, where she received a Masters degree in nutrition in 1987, followed by a Ph.D. in microbiology in 1990. Her thesis was entitled, "Microbial ecophysiology in the rumen of sheep fed tropical forages." She held two postdoctoral training positions, the first at INRA-Theix in France and the second at Centro de Biología Molecular Severo Ochoa at the Universidad Autonoma of Madrid, Spain. She worked at the Venezuelan Institute of Scientific Research until 2002. She worked at the University of Puerto Rico in San Juan from 2002 to 2012, at New York University from 2012 to 2017, and is currently a professor at Rutgers, The State University of New Jersey, and a leading member of Rutgers University Microbiome Program (RUMP).
Research and service
Domínguez-Bello first proposed the idea of restoring the microbiota in C-section born neonates -void of the natural maternal birth canal microbes. She ran the first observational trial and is now involved in a randomized clinical trial to determine effects of restoring natural microbes at birth, on the baby health. She pioneered work showing the loss of human microbiome diversity and change of environmental home microbial exposures associated with urbanization and initiated the efforts to preserve the global human microbiome diversity in the Microbiota Vault, a repository for the future health of humanity.
She became a fellow of the Infectious Diseases Society of America (IDSA) in 2008 and a member of the American Academy of Microbiology in 2013. In 2015 she received the Arturo L. Carrión Muñoz|Arturo Carrion Award from the Puerto Rico Society of Microbiology and became member of the Academy of Sciences of Latin America (ACAL). In 2019 she became fellow of the Canadian Institute for Advanced Research (CIFAR) program in Humans & the Microbiome.
An advocate for using technology that respects nature, she also has promoted since 2019 the creation of Baby Friendly Spaces (BFS) at work, as a way to improve maternal and infant health, with direct breastfeeding by working mothers, and is a member of the NJ Breastfeeding Coalition.
Personal life
Domínguez-Bello was married to Luis Raul Pericchi, with whom she had one child, Adriana Pericchi Domínguez. She married fellow microbiome researcher Martin J. Blaser in 2013.
References
Further reading
1959 births
Living people
People from Caracas
Venezuelan women scientists
Rutgers University faculty
Simón Bolívar University (Venezuela) alumni
Alumni of the University of Aberdeen
American scientists
Ecologists | María Gloria Domínguez-Bello | [
"Environmental_science"
] | 712 | [
"Ecologists",
"Environmental scientists"
] |
51,395,548 | https://en.wikipedia.org/wiki/Object%20point | Object points are an approach used in software development effort estimation under some models such as COCOMO II.
Object points are a way of estimating effort size, similar to Source Lines Of Code (SLOC) or Function Points. They are not necessarily related to objects in Object-oriented programming, the objects referred to include screens, reports, and modules of the language. The number of raw objects and complexity of each are estimated and a weighted total Object-Point count is then computed and used to base estimates of the effort needed.
See also
COCOMO (Constructive Cost Model)
Comparison of development estimation software
Function point
Software development effort estimation
Software Sizing
Source lines of code
Use Case Points
References
Software development | Object point | [
"Technology",
"Engineering"
] | 140 | [
"Software engineering",
"Computer occupations",
"Software development"
] |
51,396,023 | https://en.wikipedia.org/wiki/Dynamic%20Graphics%20Project | The Dynamic Graphics Project (commonly referred to as dgp) is an interdisciplinary research laboratory at the University of Toronto devoted to projects involving Computer Graphics, Computer Vision, Human Computer Interaction, and Visualization. The lab began as the computer graphics research group of Computer Science Professor in 1967. Mezei invited Bill Buxton, a pioneer of human–computer interaction to join. In 1972, Ronald Baecker, another HCI pioneer joined dgp, establishing dgp as the first Canadian university group focused on computer graphics and human-computer interaction. According to csrankings.org, for the combined subfields of computer graphics, HCI, and visualization the dgp is the number one research institution in the world.
Since then, dgp has hosted many well known faculty and students in computer graphics, computer vision and HCI (e.g., Alain Fournier, Bill Reeves, Jos Stam, Demetri Terzopoulos, Marilyn Tremaine). dgp also occasionally hosts artists in residence (e.g., Oscar-winner Chris Landreth). Many past and current researchers at Autodesk (and before that Alias Wavefront) graduated after working at dgp. dgp is located in the St. George Campus of University of Toronto in the Bahen Centre for Information Technology. dgp researchers regularly publish at ACM SIGGRAPH, ACM SIGCHI and ICCV.
dgp hosts the Toronto User Experience (TUX) Speaker Series and the Sanders Series Lectures.
Notable alumni
Bill Buxton (MS 1978)
James McCrae (PhD 2013)
Dimitris Metaxas (PhD 1992)
Bill Reeves (MS 1976, Ph.D. 1980)
Jos Stam (MS 1991, Ph.D. 1995)
References
Computer graphics
Computer vision
Human–computer interaction
University of Toronto | Dynamic Graphics Project | [
"Engineering"
] | 372 | [
"Packaging machinery",
"Human–machine interaction",
"Artificial intelligence engineering",
"Human–computer interaction",
"Computer vision"
] |
51,396,512 | https://en.wikipedia.org/wiki/Isao%20Arita | was a Japanese physician, virologist and vaccination specialist who headed the World Health Organization (WHO) Smallpox Eradication Unit in 1977–85. During this period, smallpox became the first infectious disease of humans to be eradicated globally. He and his colleagues were awarded the Japan Prize in 1988 for this work. He also advised the successful programme to eradicate poliovirus from the Western Pacific region.
Education and early career
Arita was born in Kumamoto, southern Japan, in 1926. After gaining his medical degree from Kumamoto Medical School in 1950, he spent a decade working for the Japanese Ministry of Health and Welfare as a medical officer in the Infectious Disease Control section. For part of this time he worked on vaccine control and standardisation, an area in which he received training at the Paul Ehrlich Institute in Germany.
Smallpox eradication programme
Arita's work for the WHO smallpox eradication programme started in 1962. He spent around 2 years working on eradication in Liberia, Africa. When American epidemiologist Donald A. Henderson joined the programme in 1966, Arita was the only remaining WHO technical staff member. He was a part of the WHO Smallpox Eradication Unit from its inception in 1966, serving as its deputy director under Henderson's leadership. He was responsible for developing the programme's "surveillance and containment" strategy (which replaced the unsuccessful strategy of attempting to vaccinate at least 80% of the population), as well as for increasing the supply of smallpox vaccine used by the eradication programme, and for monitoring and improving vaccine quality. He also undertook research into poxviruses, particularly monkeypox virus.
After Henderson left WHO in 1976 or 1977, Arita went on to direct the unit. Under his leadership an outbreak of variola minor in the Horn of Africa during the Ethiopian–Somali war was successfully contained, and the final case of naturally transmitted smallpox occurred in October 1977. He administered the process by which smallpox was formally certified by WHO as having been eradicated globally in May 1980. After certification, he managed the implementation of the certifying commission's recommendations. He continued to direct the unit's international surveillance activities. He was also involved in formulating policies on issues including ongoing vaccination and laboratory stocks of variola virus, and in archiving WHO's data on the eradication programme. In 1999, he was one of several scientists to argue for the destruction of the remaining stocks of variola virus.
Arita was one of the lead authors, with Frank Fenner and Henderson, of the WHO publication Smallpox and its Eradication, an exhaustive 1460-page volume which was published in January 1988. Arita also wrote his own personal account in the 2010 book, The Smallpox Eradication Saga. An Insider's View.
Later career
In 1985, Arita left WHO to direct the Kumamoto National Hospital in Japan, a position he retained until his retirement in 1992. He advised Morihiro Hosokawa (then governor of the Kumamoto prefecture) on the foundation of the Agency for Cooperation in International Health (ACIH) in 1990, and became its chair in 1993. The ACIH aims to promote disease prevention in developing countries, and the body has organised international conferences on vaccines and other topics. In the early 1990s, Arita called international attention to the issues surrounding the supply of vaccines and vaccine quality in developing countries, and advocated for these countries to move towards being self-sufficient in vaccine production.
From 1990 until 2004, he chaired the Technical Advisory Group to WHO's Expanded Programme on Immunization and Poliomyelitis Eradication in the Western Pacific Region. The programme was successful in eradicating wild poliovirus from this region in 1997.
He also served on the expert committee that certified the eradication of wild poliovirus from North and South America in 1997. Despite these regional successes, the global eradication of polio – planned for 2000 – has yet to be achieved. In 2006, with Fenner and Miyuki Nakane, Arita published an opinion piece in the journal Science that questioned whether it was feasible to eradicate polio globally, and suggested that control might be a preferable option.
Arita also published on severe acute respiratory syndrome, measles, hepatitis B, hepatitis C and other viral diseases.
Death
Arita died on 17 March 2023, at the age of 96.
Awards and honours
In 1988, Arita, together with Henderson and Fenner, was awarded the Japan Prize – considered the Japanese equivalent of the Nobel Prize – for his work on smallpox eradication. The Japanese government conferred on him the title of "national treasure".
Selected publications
Books
Isao Arita. The Smallpox Eradication Saga. An Insider's View (Orient Longman; 2010)
Frank Fenner, Donald A. Henderson, Isao Arita, Zdenek Jezek, Ivan Danilovich Ladnyi. Smallpox and its Eradication (WHO; 1988) (downloadable at )
Articles
See also
Koyama Shisei
References
Sources
Frank Fenner. Nature, Nurture and Chance: The Lives of Frank and Charles Fenner (ANU E Press; 2006) ()
William Muraskin. The Politics of International Health: The Children's Vaccine Initiative and the Struggle to Develop Vaccines for the Third World (SUNY Press; 1998) ()
Jonathan B. Tucker. Scourge: The Once and Future Threat of Smallpox (Grove Press; 2001) ()
Franklin White, Lorann Stallones, John M. Last. Global Public Health: Ecological Foundations (Oxford University Press; 2013) ()
1926 births
2023 deaths
People from Kumamoto
Smallpox eradication
Vaccinologists
Japanese virologists
Japanese expatriates in West Germany
World Health Organization officials | Isao Arita | [
"Biology"
] | 1,180 | [
"Vaccination",
"Vaccinologists"
] |
51,398,231 | https://en.wikipedia.org/wiki/WinX%20MediaTrans | WinX MediaTrans is a mobile media file manager software. It helps file synchronization between phones and Windows PC, importing exporting photos, music, videos, and mount iPhone iPad as USB drive. Currently iOS devices are supported only.
Main features
1. Transfer photo
WinX MediaTrans is a photo file manager. It transfers photos (HEIC, PG, PNG, BMP) from iOS to computer for saving space. It can also export HEIC photos from iPhone X/8/7 to JPEG for viewing on PC. Exporting 100 4K pictures from iPhone to PC takes 8 seconds. Transferring pictures from PC to iOS is not supported.
2. Sync music
Music synchronization between iPhone, iPad and computer is permitted. Also it can create, edit and delete music playlist, as well as edit music information, including artist, title, album, etc.
3. Import/export video
Importing videos from computer to iOS devices is enabled with this app and vice versa. It supports converting videos incompatible with iOS to supported formats before the syncing. Hardware acceleration is permitted as well. And videos transferred from PC to iPhone will be auto rotated in full screen.
See also
Comparison of file managers
References
External links
File managers
Multimedia software | WinX MediaTrans | [
"Technology",
"Engineering"
] | 259 | [
"Multimedia",
"Multimedia software",
"Software engineering stubs",
"Software engineering"
] |
51,399,698 | https://en.wikipedia.org/wiki/Thought%20vector | Thought vector is a term popularized by Geoffrey Hinton, the prominent deep-learning researcher, which uses vectors based on natural language to improve its search results.
References
Search algorithms | Thought vector | [
"Technology"
] | 36 | [
"Computing stubs",
"Computer science",
"Computer science stubs"
] |
51,400,740 | https://en.wikipedia.org/wiki/OPCW%E2%80%93The%20Hague%20Award | The OPCW–The Hague Award is an annual award founded by the OPCW as a result of their being presented with the 2013 Nobel Peace Prize. The purpose of the Award is to honour and recognize individuals and institutions that have significantly contributed towards the goal of a world free of chemical weapons.
Foundation
In 2014, the Organisation for the Prohibition of Chemical Weapons (OPCW) established the OPCW–The Hague Award to honour select individuals and institutions by highlighting their exceptional contributions towards the goal of a world permanently free of chemical weapons. The award was created as a legacy of the OPCW winning the 2013 Nobel Peace Prize for their "extensive work to eliminate chemical weapons". The OPCW—The Hague Award Fund was created using the approximately €900,000 monetary prize which accompanied the Nobel Peace Prize, and is also supported financially by the City of The Hague, where the OPCW is based.
The winner of the Award is presented with a medal, certificate and a monetary prize of up to €90,000. As an essential partner in both establishing and maintaining the Award, the commemorative medal features an engraving of the OPCW headquarters building with the official coat of arms of the City of The Hague au verso. This reflects The Hague's stature as the international city of peace and justice, and its historic support of the OPCW mission statement; a ban on chemical weapons has been in effect in the Netherlands since the Hague Convention of 1899.
Past winners
The roster of past winners includes experts in analytical chemistry techniques, medical toxicology, the ethical use of chemistry, and the legal frameworks governing the elimination of all chemical weapons.
2014 winners
In its first edition, the Award was presented to Dr Robert Mathews of the Commonwealth of Australia, and also to the organisation VERIFIN of the Republic of Finland.
Dr Robert Mathews
Dr Robert Mathews previously lead the Nuclear, Biological and Chemical Arms Control Unit in the Australian Defence Science and Technology Organisation (DSTO), which he founded in 1974. Through his work Dr Mathews has contributed greatly to the OPCW since its formation in 1997, and has provided invaluable expertise in both the disarmament of chemical weapons, and the advancement of innovative protective counter-measures against their use.
VERIFIN
VERIFIN (the Finnish Institute for Verification of the Chemical Weapons Convention) operates as part of the Department of Science at the University of Helsinki, and was founded in 1994. VERIFIN has served as the National Authority of Finland since 1998, as defined under Article VII of the Chemical Weapons Convention. As such, VERIFIN works closely with the main body of the OPCW and has provided considerable assistance through the development of advanced verification methods for use in the detection and identification of chemical weapons and their components; most recently used during the investigation into the alleged use of chemical weapons in the Syrian Arab Republic.
2015 winners
In 2015, the Award was presented to Dr Mahdi Balali-Mood of the Islamic Republic of Iran, and Dr Alastair Hay of the United Kingdom.
Dr Mahdi Balali-Mood
Dr Mahdi Balali-Mood, a leading authority in medical toxicology, was presented with The OPCW–The Hague Award due to his outstanding work in treating the victims of chemical weapon use; most prominently during the 1980–1988 Iran-Iraq War. His wealth of experience in the field lead to the establishment of his own clinic in the aftermath of the war to provide care for victims affected by the long term consequences of surviving exposure to chemical weapons.
Dr Alastair Hay
Dr Alastair Hay a preeminent expert in the field of occupational health and toxicology, and in this capacity he has participated in numerous missions to investigate alleged uses of chemical weapons. His training courses for doctors and OPCW inspectors working in Syria have aided them in better understanding the long-term health effects of exposure to chemical weapons, and establishing more effective protocols for the treatment of victims. Dr Hay is also a leading figure in international efforts to advocate the peaceful applications of chemistry and biology.
2017 Winners
African Centre for the Study and Research on Terrorism (ACSRT)
International Master Courses in Protection Against CBRNe Events
2019 Winners
Robert Mikulak
Cheng Tang
International Union of Pure and Applied Chemistry
2022 Winners
Special Risks Brigade of the Federal Police of Argentina
Chemical Weapons Convention Coalition
Population Protection Institute, Fire Rescue Service of the Czech Republic
See also
List of chemistry awards
References
Peace awards
Chemistry awards
International awards | OPCW–The Hague Award | [
"Technology"
] | 902 | [
"Science and technology awards",
"Chemistry awards",
"International science and technology awards"
] |
51,401,190 | https://en.wikipedia.org/wiki/Quaject | In computer science, a quaject is an object-like data structure containing both data and code (or pointers to code), exposed as an interface in the form of callentries, and can accept a list of callentries to other quajects for callbacks and callouts. They were developed by Alexia Massalin in 1989 for the Synthesis kernel, and named for the Qua! Machine, a unique hardware platform built by Massalin. The origin of the term 'qua' is unclear; Massalin claims humorously that it is a sound made by koalas.
The main purpose of quajects is to provide an abstraction to manage self-modifying code, by allowing runtime code optimizing on a per-object basis. While the original Synthesis kernel required quajects to be written in hand-developed assembly language, this was done to avoid developing a complex compiler; Massalin noted that just-in-time compilation (JIT) for a high-level programming language that permits runtime code generation, as in Lisp or Smalltalk, can also apply this approach, though she also asserted that the complexity of such a compiler was likely to be prohibitive.
Quajects differ from more conventional objects in two key ways: first, they always use a form of the dependency injection pattern to manage both interfaces to other quajects, and continuations out of the quaject; the list of callentry references for this is part of quaject creation, and may be updated during the quaject's lifetime. Second, and more critically, a given quaject's set of methods can be unique to the specific quaject; methods for a type or class of quajects are stored as one or more templates, rather than as fixed code. While shared methods can be accessed through a common table of pointers, individual quajects can also have methods that are generated specifically to tailor the performance for that quaject's behavior.
References
Operating system technology | Quaject | [
"Technology"
] | 426 | [
"Computing stubs",
"Computer science",
"Computer science stubs"
] |
51,404,088 | https://en.wikipedia.org/wiki/FarmBot | FarmBot is an open source precision agriculture CNC farming project consisting of a Cartesian coordinate robot farming machine, software and documentation including a farming data repository. The project aims to "Create an open and accessible technology aiding everyone to grow food and to grow food for everyone."
History
The FarmBot project was started in 2011 by American Rory Aronson whilst studying mechanical engineering at California Polytechnic State University. Aronson attended an elective course in organic agriculture where he learned about a tractor that used machine vision to detect and cover weeds which removed the need for herbicides or manual labour, the tractor cost over US$1 million.
In March 2014 Aronson began working on the project full-time funded by a grant from the Shuttleworth Foundation. Firmware developer Tim Evers and software developer Rick Carlino later joined the project as core developers. Rory Aronson created the company Farmbot.io to provide hardware kits and software services and to serve as a funding source to maintain the open source community.
In 2014 and 2015, FarmBot was entered into the Hackaday Prize, where it became a finalist in 2015. After nine design iterations, the Farmbot Genesis began preorders in July 2016 as the first commercially available version of FarmBot.
Farmbot Genesis
Capabilities
The FarmBot Genesis is able to plant over 30 different crops within the same area at the same time and is able to operate indoors, outdoors and in covered areas. It can perform almost all processes prior to harvesting including sowing, mechanical weed control and watering while accounting for factors such as age of the plant and local weather conditions.
FarmBot Genesis is controlled through a web based interface allowing remote access from any location on most internet enabled devices. It uses an online crop database called OpenFarm to create an optimal planting plan based on the size of the adult crop.
Components
The Farmbot Genesis is an open source hardware machine and is designed around reproduce-ability and availability of components, it can be created using common tools and processes. Its electronics stack consists of a Raspberry Pi 3 and Arduino Mega 2560 with a RAMPS 1.4 shield and a camera to record data. The universal tool mount and other tools are 3D printed and are designed to be created with hobby level fused deposition model 3D printers e.g. a RepRap printer. It has two electrical connections and connectors for liquid or gas which are magnetically coupled.
The software for the FarmBot Genesis runs through a web interface allowing the machine to be controlled on most internet enabled devices. All software is available under the MIT license and is available on GitHub.
See also
Open Source Ecology
RepRap project
References
External links
Official product website
FarmBot Project community website
FarmBot Github repository
Open hardware electronic devices
DIY culture
3D printing
Engineering projects
Computer output devices
Open hardware organizations and companies
Free and open-source software
Fused filament fabrication
Agricultural robotics | FarmBot | [
"Engineering"
] | 586 | [
"nan"
] |
51,404,750 | https://en.wikipedia.org/wiki/Eloise%20Kruger | Eloise Andrews Kruger (June 26, 1914 – November 19, 1995) was an American miniature collector from Lincoln, Nebraska, who was known for her collection of historically-accurate American miniatures.
Early life
Kruger was born in Lincoln, Nebraska, on June 26, 1914, as the eldest of Vernon and Luella Dierks Andrews's four daughters. Her cousin, Carl Rohman, acclaimed supporter of the Sheldon Memorial Art Gallery, remembers her being a very confident young woman. Prior to the Depression, she was exposed to a high level of living. She was a passionate reader, especially on the subjects of interior design and miniature collecting.
She graduated from Lincoln High in 1932 and enrolled at the University of Nebraska. She only attended until 1934 because she wanted to help support her mother and sisters after her father abandoned the family for another woman. She lived with her aunt and uncle to help her three sisters pay for college, all of whom graduated.
She married Carl Kruger in 1939, and soon after became interested in miniature figures.
Career
She worked as a secretary, then was quickly promoted to executive secretary. Lee Syndicate hired her as an accountant, despite her lack of knowledge in the area. After buying books and studying she became adept at the trade.
During World War II, when most men were drafted, she was given war-time orders to hire and train women. Eventually she ran an all-woman accounting office until the war ended.
Even once her collection started, she still worked these jobs and helped her husband manage Paramount Laundry.
She was interested in sketching plans; she drew the house her mother built at 1935 Dakota Street.
Her accounting job allowed her to travel a lot. Her cousin, Carl (Ky), claimed that she would find many pieces for her collection on these trips.
The collection and collecting methods
"When she undertook something she did it right. She studied and studied until she got it right" attested Carl Rohman Jr.
She began collecting in the 1930s. The height of her collecting took place in the 1970s and 1980s. She became a published author in Miniature Magazine, commissioned outstanding miniature makers to create models from the American Neoclassical era, and reached out to collectors all over the country.
After assessing the number of American Neoclassical, American colonial and Victorian pieces that she commissioned, it can be assumed those were her favorite eras.
Her attention to detail was remarkable, as well as her records, documentation, and effort to learn as much about the eras as possible.
All of the models were created at 1:12 scale. The pieces ranged from furniture, decorative arts, and accessories, from nearly every English and American design style, from Renaissance to Early Modern, all of which she commissioned to look as accurate to the real pieces as possible. In 1968 alone, she wrote eighty-five different letters to collectors and artists across the country. The relationships represented varied in scope and familiarity. The key trends of these letters include writing multiple letters in one day (44% were written on Thursdays), and the increase of letters per month increasing to 34% in February. The patterns correlate with events that transpired in 1968, like the Chicago riots, her battle with undiagnosed dizzy spells, and a sprained arm that prevented her from writing.
In many of her letters she mentioned that she had an interest in creating 1:12 miniature rugs, many of which she gave away, despite the hours of work one required.
She worked on the Chippendale Back Stool that model maker, Eric Pearson, made custom for her. The flamestitch upholstery took 40 stitches per inch. In February, Eloise told Eunice Tuttle "the upholstery in this case is driving me to despair." Her two main correspondents were Thomas Devereux and Ellen Krucker, and these letters included more personal information, like politics and new cars, much more than simply invoices for her collection. Krucker was one of the two artists (aside from Pearson) that Eloise's husband thought made "worthwhile miniatures".
Eloise rented the apartment across the hall from her home, just for storing her miniatures.
Top artists are Eric Pearson with 236 pieces, Eugene Kupjack, Bob Carlisle, Warren Dick, Mell Prescott, and Betty Valentine.
Death and legacy
Kruger died on November 19, 1995, at age 81. She was survived by her sister Jean, nephews Donald Campbell and Bob Campbell, and cousin Carl Rohman. Her collection was donated to the University of Nebraska - Lincoln in 1997 and is now held in the Kruger Gallery inside the College of Architecture. This contribution included over eight hundred books on the subjects of architectural detailing, to histories in ceramics, iron work, interior design, and kitchen space planning, as well as her miniature collection of over 20,000 pieces, valued at $500,000. The Kruger Gallery now uses her collection to increase awareness of architectural and interior eras, and in the field of material culture. "I think it's great [to be at UNL]. She valued education, she would be terribly pleased" said her nephew Bob.
Kruger's collection is now a part of the School of Global Integrated Studies at UNL and is being displayed in a new gallery space "The Eloise Kruger Gallery of Miniatures", room 834 in the Oldfather building.
References
1914 births
1995 deaths
Scale modeling
People from Lincoln, Nebraska
American accountants
American women accountants
American art collectors | Eloise Kruger | [
"Physics"
] | 1,102 | [
"Scale modeling"
] |
51,404,957 | https://en.wikipedia.org/wiki/DxOMark | DXOMARK is a commercial website described as "an independent benchmark that scientifically assesses smartphones, lenses and cameras". Founded in 2008, DXOMARK was originally owned by DxO Labs, a French engineering and consulting company, which is headquartered in Boulogne-Billancourt, Paris, France. DXOMARK Image Labs was separated from DxO Labs in September 2017, and was later re-branded to DXOMARK in 2019. DXOMARK is now a wholly independent privately-owned company.
DXOMARK scores are used in many independent news publications and specialist media sites.
DXOMARK rating systems
The score(s) awarded by DXOMARK are based upon a comprehensive and highly-documented, but commercially secret methodology. An overall 'headline' (v) score is awarded, but that is based upon an aggregated overview of a number of other very specific and detailed test attributes, although the actual weighting of those individual attributes is unknown. DXOMARK themselves stress that "the overall score is not a weighted sum of the sub-scores. It is a proprietary and confidential mapping of sub-scores into a combined score". DXOMARK also highlight that they consult directly with the equipment manufacturers, with the objective of helping them make better cameras.
In respect of specific score figures, it is not clear what headroom or ceiling level is available to the DXOMARK scoring system. Some early high performers might have suggested an upper limit of 100 points, yet later high performers are awarded scores in excess of 100. It is also important to note that the DXOMARK score is not based on any averages.
Camera sensor rating
The DXOMARK Sensor Score measures several important image quality metrics of the RAW image captured by the camera's sensor. The overall score is a confidential combination of three sub-scores:
Colour depth, measured in bits, called a Portrait score;
Dynamic range, measured in stops of dynamic range, called a Landscape score;
Low-light performance, measured in an ISO equivalent, called a Sports score.
Another metric, the Perceptual MegaPixel (P-MPix), defined as 'the unit of a sharpness measurement', is used to rate the resolution a camera produces when paired to a particular lens. DXOMARK claims that P-MPix is a more accurate and relevant value for photographers to consider than alternate measures of sharpness when evaluating camera and lens image quality. As of December 2015, the Canon EF 300mm f/2.8L IS II USM lens mounted on a Canon EOS 5DS R has the highest measured P-MPix (45 P-MPix), followed by the Carl Zeiss APO Sonnar T* 2/135 ZE (41 P-MPix on Canon EOS 5DS R and 36 P-MPix on Nikon D800E).
Camera lens rating
The DXOMARK Lens Score provides ratings for camera lenses, as tested using its proprietary tool-set in combination with various camera models. As with the DxOMark Sensor Score, the DXOMARK Lens Score is an aggregation of five separate sub-scores; namely: sharpness, distortion, vignetting, transmission, and chromatic aberration. As of December 2024, three lenses have the highest aggregated Lens Score of 55: the Nikon Nikkor Z 85mm f/1.2 S, the Nikon Nikkor Z 58 mm f/0.95 S Noct (both Nikon Z-mount) and the Sigma 50mm F1.4 DG DN Art (for Sony E-mount).
Smartphone camera rating
As smartphones began to overtake point-and-shoot cameras, DXOMARK began testing smartphones and other mobile devices in 2011, and introduced DXOMARK Mobile in 2012. A major update was made in September 2017, adding tests designed to stress the capabilities of current-model smartphones, including those with dual lenses; such as lower-light shooting, telephoto zoom, depth effect, and bokeh. In September 2019, the DXOMARK Mobile score was renamed DXOMARK Camera.
DXOMARK Camera Overall Score is the headline number reported for each tested device, and consists of a proprietary combination of DXOMARK Camera Photo, and DXOMARK Camera Video category scores.
DXOMARK's Camera Photo score is a proprietary combination of nine category sub-scores:
Exposure and contrast
Colour
Auto-focus
Texture
Noise
Artifacts
Night (enhanced from Flash, September 2019)
Zoom
Bokeh
Wide (added September 2019)
Preview (added October 2020)
DXOMARK's Camera Video score includes six of the same sub-scores as DXOMARK's Mobile Photo score (Exposure, Colour, Auto-focus, Texture, Noise, and Artifacts), along with Stabilisation.
DXOMARK's tests are conducted by the company's technical staff under a variety of lighting conditions; ranging from low-light 1 Lux, to bright daylight outdoors. Sub-scores are combined using a proprietary and confidential mapping into an overall score. Tests are also confined to default modes, except for Zoom and Bokeh, which has caused reviewers to be cautious when using them.
Selfie-camera rating
On 22 January 2019, DXOMARK started to release the results of a new metric; testing the front-facing 'selfie' cameras on smartphones. These new standalone DXOMARK Selfie tests are undertaken for both Photo and Video, though the 'headline' DXOMARK Selfie score will combine both. For DXOMARK Selfie Photo, there are sub-scores for Exposure, Colour, Focus, Texture, Noise, Artifacts, Flash, and Bokeh. For DXOMARK Selfie Video, sub-scores include Exposure, Colour, Focus, Texture, Noise, Artifacts, and Stabilisation.
Smartphone audio rating
On 10 October 2019, DXOMARK introduced a new Audio benchmark for smartphones. Phones are tested for playback using their internal speakers, and for recording using their built-in microphones. DXOMARK Audio tested categories include:
Timbre (frequency response, treble/mid-range/bass, total balance, volume dependency)
Dynamics (attack, bass precision, punch, volume dependency)
Spatial (wideness, balance, distance, localisation)
Volume (maximum, minimum, user volume consistency)
Artifacts (noise, pumping, clipping, user artifacts, other artifacts)
For recording only:
Background (directivity, noise profile, artifacts)
Smartphone display ratings
In October 2020, DXOMARK introduced a rating system for mobile device displays (screens). DXOMARK Display tests over 400 measurements, and more than 20 hours of laboratory evaluations and real-life scenarios. The result includes six sub-scores: Readability, Colour, Video, Motion, Touch, and Artifacts.
Wireless speaker ratings
In November 2020, DXOMARK introduced a rating system, DXOMARK Sound, for wireless speakers, based on factors including both lab tests using sound-level meters and calibrated microphones, as well as 20 hours of perceptual assessment. Customized music clips, created by DXOMARK in collaboration with professional musicians and recording studios, include those in the styles of jazz, hip-hop, classical, pop, rock, Latin, electronic, and alternative genres.
Battery ratings
DXOMARK started smartphone battery testing on 10 May 2021. DXOMARK's battery test protocol is based on 70 measurements and takes 150 hours to test.
Comparison tool
Users of the DXOMARK website can select several devices of the same class, and have the website display a comparison of their test scores and graphical versions of the actual test data.
Analyzer
Analyzer is a suite of software tools published by DXOMARK, that includes test targets and test equipment. It is used by camera companies, as well as press publications and websites; to test sensors, lenses, and standalone cameras, as well as mobile devices with cameras. Testing can be performed on both RAW and JPEG images, as well as video. Analyzer is also the analysis engine behind dxomark.com Results can be displayed either numerically or graphically. Originally introduced by DxO Labs, Analyzer is now a product of DxOMark, which has been separated from DxO.
Analyzer includes modules for testing optics, sensors, stabilisation, video, timing, and 3D features.
Usage in industry
DXOMARK ratings are often used by the press to describe the image quality characteristics of their cameras and mobile devices. High DXOMARK Camera ratings have also been featured as hallmarks of quality in vendor announcements and marketing materials, although reviewers are careful to note that the ratings only reflect image quality. DXOMARK also provides consulting services to hardware manufacturers, related to image quality.
See also
Comparison of smartphones
References
Citations
Further reading
External links
www.DxOMark.com — official website
DxOMark press releases — at www.DxOMark.com
Analyzer website — at DxOMark.com corporate site
DxOMark Image Labs SAS — at DxOMark.com corporate site
Smartphones
Product testing
Metrics
French photography websites
Software companies of France
Privately held companies of France
Photography companies of France
Benchmarks (computing)
DxO Labs | DxOMark | [
"Mathematics",
"Technology"
] | 1,948 | [
"Metrics",
"Quantity",
"Computing comparisons",
"Computer performance",
"Benchmarks (computing)"
] |
51,405,191 | https://en.wikipedia.org/wiki/Markar%20Clock%20Tower | The Markar Clock Tower also known as Borj-e Sa'at-e Markar () is a historic clock tower in Yazd, Iran. It is located on the geographic centre of Iran.
History
The cost of its construction was paid by a Zoroastrian from India, Pashutanji Marker. The clock tower was constructed on 26 Oct 1942. The Markar clock tower or Borj-e Sa'at Markar is located in the middle of the Marker Clock Plaza.
Architecture
The tower has a height of about 4 meters, a square shape, a pyramid on, and looks like an obelisk. The Tower is located in the center point of Iran coordinately. The movement system has been made in London by J. Smith & Sons Co. The spring should be charged weekly.
Mirza Soroush obtained permission for, and supervised the construction of, the Markar Plaza with gardens around it. The plaza is situated on the road to Kerman just north of the Markarabad school entrance.
There are poems on four sides of tower from a local poet, Naser, which located in two lines and should read clockwise. The upper line poem is about Ferdowsi, but the lower line is about the benefactor. The last hemstitch (شادم از کردار نیک مارکار) implies the end time/year of building of tower in Abjad numerals system; 13:20 or 1320 (Solar Hijri), as well as Markar's religion (Zoroastrian) by using one of his religion maxims: "Good Deeds"; (Persian: کردار نیک).
This hemstitch has an Abjad numeric value: 300+1+4+40+1+7+20+200+4+1+200+50+10+20+40+1+200+20+1+200=1320
Etymology
Sa'at means "clock", which refers to the four face clock in top of the tower. Markar is the name of benefactor who paid the cost of building.
Gallery
References
External links
Buildings and structures in Yazd
Geographical centres | Markar Clock Tower | [
"Physics",
"Mathematics"
] | 457 | [
"Point (geometry)",
"Geometric centers",
"Geographical centres",
"Symmetry"
] |
51,406,305 | https://en.wikipedia.org/wiki/Macroinvertebrate%20Community%20Index | Macroinvertebrate Community Index (MCI) is an index used in New Zealand to measure the water quality of fresh water streams. The presence or lack of macroinvertebrates such as insects, worms and snails in a river or stream can give a biological indicator on the health of that waterway. The MCI assigns a number to each species of macroinvertebrate based on the sensitivity of that species to pollution. The index then calculates an average score. A higher score on the MCI generally indicates a more healthy stream.
The MCI (Macroinvertebrate Community Index) relies on an allocation of scores to freshwater macroinvertebrates based on their pollution tolerances. Freshwater macroinvertebrates found in pristine conditions would score higher than those found in polluted areas. MCI values can be calculated using macroinvertebrate presence-absence data using this equation:
MCI = [(site score)/(# of scoring taxa)]*20
Previous water quality assessments have relied on both chemical and habitat analysis, however, these methods have been proven to be insufficient due to pollution from nonpoint sources. Species living in an aquatic environment may be the best natural indicator of environmental quality and reveal the effects of any habitat alteration or pollution, and have proved to respond to a wide range of stressors such as sedimentation, urbanization, agricultural practices and forest harvesting effects. Any changes that may occur in macroinvertebrate communities that lead to a reduction in diversity increase the dominance of pollution-tolerant invertebrates, such as oligochaetes and chironomids. Thus, a lack of species diversity and low biotic index scores of inhabitant macroinvertebrates may be an indicator of poor water quality. The risk of water quality degradation is the greatest in low-elevation areas, where high intensity agriculture and urban development are the dominant land uses.
Macroinvertebrate communities are the preferred indicators of aquatic ecosystem health because they are very easy to both collect and identify, and have short life spans, thus responding very quickly to changes in their environment. The MCI methods of utilizing macroinvertebrate communities to assess the overall health of an aquatic environment continues to be the most reliable, applicable, and widely acclaimed method around the world.
Variations on the MCI
In addition to the MCI indexed defined above, there are also two other variations of the MCI. The QMCI (Quantitative Macroinvertebrate Community Index) and the SQMCI (Semi-Quantitative Macroinvertebrate Community Index). Both MCI and QMCI are widely used in countries like New Zealand. The combination of widespread use and good performance of the MCI and the QMCI in detecting water quality in aquatic ecosystems has sparked interest in further refinement of the methods in New Zealand. The QMCI, just like the MCI, was initially designed to evaluate the organic enrichment in aquatic ecosystems. The third index, the SQMCI, was created to reduce sampling and processing efforts required for the QMCI. The SQMCI will respond in a similar matter to the QMCI in community dominance, however, will require fewer samples to achieve the same precision. The SQMCI gives a comparative appraisal to the QMCI with under 40% of the exertion, in circumstances that macroinvertebrate densities are not required. This diminishes expenses and also enhances the logical solidness of biomonitoring projects. Both the QMCI and SQMCI are similar to the MCI in the way that they are graded on a 1 (extremely tolerant) to 10 (highly intolerant) scale. However, they differ in the way that MCI is calculated using presence-absence data whereas QMCI uses quantitative or percentage data. Having a qualitative, quantitative, and semi-quantitative version of the same index has raised some questions as to if this is a good thing or not. All three indexes have the same purpose, which is to measure the quality of an aquatic ecosystem, however, there are no clear recommendations about when each one is most appropriate to be used. In a study conducted on 88 rivers, Scarsbrook et al. (2000) concluded MCI is more useful than the QMCI for recognizing changes in stream water quality over time. Having three forms of a similar index may prompt to various conclusions and also opens the route for specific utilization of either file to give bias to a specific position or position taken by a specialist. In August 2019, the Ministry for the Environment released a draft National Policy Statement for Freshwater Management, and a report from Scientific and Technical Advisory Group that recommended including three different measures, MCI, QMCI and Average Score Per Metric (ASPM).
QMCI values can be calculated using:
QMCI = Σ_(i=1)^(i=s)▒(n_i*a_i)/N
SQMCI values can be calculated similar to QMCI except that coded abundances are substituted for actual counts. Example:
SQMCI = Σ_(i=1)^(i=s)▒(n_i*a_i)/N
Factors Influencing MCI
There are several factors which can affect the data acquisition of MCI when assessing the water quality of an aquatic ecosystem. Hard-bottom and Soft-bottom channels can often yield different results and many researchers will use two different versions of the MCI. For example, in a study by Stark & Mallard (2007) they discuss that hard and soft bottom channels have separate versions of the MCI and the two versions can not be combined into one data set because of the differences in taxa and tolerance values.
Spatial variability is also of interest in terms of affecting the data acquired through MCI. Sites which are progressively down stream often tend to yield a lower MCI value. There may also be confounding influences between riffles, runs, or pools with a single stream reach.
Depth and velocity have also been raised as a concern with regards to effecting results, however Stark (1993) investigated the influences of the sampling method, water depth, current velocity and substratum on the results and found that both MCI and QMCI are independent of depth, velocity, and substratum from macroinvertebrate samples collected from stony riffles. This finding is an advantage for the assessment of water pollution.
There have been several studies conducted on seasonal variability, which has been considered the main influential factor on the assessment of water quality. It has been concluded that all models should test data that has been collected in the season as the reference data, which is being used.
There have been several other factors such as water temperature, invertebrate life histories and dissolved oxygen levels that have all been explained as causes of seasonal variability. Warmer seasons have biotic indices that are indicative of poorer stream health. Warmer seasons such as summer, would have increased temperatures therefore increasing water temperature and decreasing the amount of dissolved oxygen in the water making the environment less ideal to aquatic macroinvertebrates. In return, this effects the density of macroinvertebrate population and changes the results of the indices.
References
External links
A user guide for Macroinvertebrate Community Index
Discussion on Radio New Zealand about MCI values of Hawkes Bay streams and rivers
List of indicator species used to calculate the MCI number
Environmental science
Water
Water management
Water pollution
Water in New Zealand | Macroinvertebrate Community Index | [
"Chemistry",
"Environmental_science"
] | 1,526 | [
"Water",
"Hydrology",
"nan",
"Water pollution"
] |
51,406,524 | https://en.wikipedia.org/wiki/KFRlib | KFRlib is an open-source cross-platform C++ DSP framework written in C++.
It is covered by a dual GPL/commercial license.
Official support
Supported platforms
KFR is supported on the following platforms.
Mac OS X
Linux
Microsoft Windows
iOS
Android
Supported compilers
Xcode 6.3 and later
Clang 3.6 and later
Visual Studio 2015 using LLVM-vs2014 toolkit
Features
Optimized for ARM NEON, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, AVX, AVX2 instruction sets
Fast Fourier transform
Convolution
Finite impulse response filters
Infinite impulse response filters
Digital biquad filter
Sample rate conversion
Window function
Goertzel algorithm
Digital delay line
Pseudorandom number generator
SIMD versions of many C mathematical functions
References
External links
Official website
C++
C++ libraries
Multimedia software | KFRlib | [
"Technology"
] | 190 | [
"Multimedia",
"Multimedia software"
] |
51,406,533 | https://en.wikipedia.org/wiki/Racah%20seniority%20number | The Racah seniority number (seniority quantum number) was introduced by Giulio Racah for the classification of electrons in an atomic configuration. The "seniority number", in a loosing statement, is quantum number additional to the total angular momentum and total spin , which gives the degree of unpaired particles.
A spin-independent interaction is assumed with the property
,
where is the combined angular momentum, magnetic quantum number, is electrons' orbital angular momenta, and is the dimensionless magnetic moment. The equation above shows there is no interaction unless the two electrons' orbital angular momenta are coupled to . The eigenvalue is the "seniority number" .
References
Quantum mechanics | Racah seniority number | [
"Physics"
] | 144 | [
"Theoretical physics",
"Quantum mechanics"
] |
51,407,154 | https://en.wikipedia.org/wiki/Reflective%20crack | A reflective crack is a type of failure in asphalt pavement, one of the most popular road surface types. Asphalt pavement is impacted by traffic and thermal loading. Due to loading, cracks can appear on pavement surface that can reduce the Pavement Condition Index (PCI) dramatically.
The pavement can be maintained by overlay. Cracks under the overlay can cause stress concentration at the bottom of the overlay. Due to the repeated stress concentration, a crack starts in the overlay that has a similar shape to the crack in the old pavement. This crack is called a "reflective crack".
Reflective cracking can be categorized as one of the distresses in asphalt pavement. It can affect the general performance and durability of the pavement. A reflective crack can also open a way for water to enter the pavement's body and increase the deterioration rate. Reflective cracks can also happen in overlays placed on joints or cracks in composite pavements such as concrete pavements. Another type of road infrastructure, dynamic inductive charging infrastructure, was found to increase the occurrence of reflective cracks in road surfaces.
See also
Asphalt concrete degradation and restoration
References
Civil engineering
Pavement engineering | Reflective crack | [
"Engineering"
] | 233 | [
"Construction",
"Civil engineering"
] |
49,063,452 | https://en.wikipedia.org/wiki/Computer%20Research%20Corporation | The Computer Research Corporation (CRC) was an early developer of minicomputers. It was founded on July 16, 1950.
The founding owners of CRC were Floyd Steele, Donald Eckdahl, Hrant (Harold) Sarkinssian, Richard Sprague, and Irving S. Reed. With the exception of Reed, all members of the CRC had been on the design team for the MADDIDA, a special-purpose digital computer developed from 1946 to 1949 for Northrop. Realizing that a problem-oriented language (POL) could be used to make a general-purpose computer function as a differential analyzer, the MADDIDA design team left Northrup in 1950 to focus on designing general-purpose computers, leading to them to found the CRC. After developing the Cadac, an early minicomputer, the CRC was sold to National Cash Register (NCR) in February 1953, launching NCR into the digital computing business.
Notes
References
Reilly, Edwin D. (2003). Milestones in Computer and Science History. Greenwood Publishing Group.
American companies established in 1950
American companies disestablished in 1953
Computer companies established in 1950
Computer companies disestablished in 1953
Defunct computer companies of the United States
Defunct computer hardware companies
Defunct computer systems companies
NCR Corporation | Computer Research Corporation | [
"Technology"
] | 264 | [
"Computing stubs",
"Computer hardware stubs"
] |
49,064,665 | https://en.wikipedia.org/wiki/Monolithic%20Power%20Systems | Monolithic Power Systems, Inc. is an American, publicly traded company headquartered in Kirkland, Washington. It operates in more than 15 locations worldwide.
Monolithic Power Systems (MPS) provides power circuits for systems found in cloud computing, telecom infrastructures, automotive, industrial applications and consumer applications.
History
Monolithic Power Systems, Inc. was founded in 1997 by Michael Hsing, who is the current CEO. Prior to the founding of the corporation, Hsing worked as a Senior Silicon Technology Developer at several analog integrated circuit companies.
The company then diversified into DC/DC products. In November 2004, Hsing took the company public with an IPO. Since then, the company has grown to incorporate 13 product lines with more than 4,000 products.
In February 2021, the company was added to the S&P 500. In 2023, the company made progress on its long-term ESG goals and diversity goals, including the addition of a second female director to its Board of Directors. The company also published its annual ESG report and launched public commitments to reduce Scope 1 and 2 greenhouse gas emissions by 40% by 2030 and to be powered globally by 75% of Renewable Electricity by 2026.
About
Monolithic Power Systems is headquartered in Kirkland, Washington. The company designs, develops, and markets for communications, storage and computing, consumer electronics, industrial, and automotive markets, in addition to supporting the electrification of transportation. Monolithic Power Systems markets its products through third-party distributors and value-added resellers. It directly markets to original equipment manufacturers, original design manufacturers, and electronic manufacturing service providers in China, Taiwan, Europe, Korea, Southeast Asia, Japan, and the United States.
Products
Monolithic Power Systems provides digital, analog, and mixed-signal integrated circuits. It offers energy-efficient DC to DC converter ICs that are used to convert and control voltages of various electronic systems, such as portable electronic devices, wireless LAN access points, computers, set top boxes, displays, automobiles, and medical equipment. The company also provides lighting control ICs for backlighting, which are used in systems that provide the light source for LCD panels in notebook computers, LCD monitors, car navigation systems, and LCD televisions. In addition, Monolithic Power Systems supports the electrification of transportation and manufactures class D Audio Amplifier products.
Locations
Monolithic Power Systems operates at 18 locations primarily in the US, Europe, and east Asia.
References
External links
Companies based in Kirkland, Washington
Companies listed on the Nasdaq
American companies established in 1997
Technology companies established in 1997
2004 initial public offerings
Computer companies of the United States
Computer hardware companies | Monolithic Power Systems | [
"Technology"
] | 537 | [
"Computer hardware companies",
"Computers"
] |
49,064,936 | https://en.wikipedia.org/wiki/Lynx%20Supercluster | The Lynx Supercluster was discovered in 1999 as ClG J0848+4453, a name now used to describe the western cluster, with ClG J0849+4452 being the eastern one. It contains at least two clusters, designated RXJ 0848.9+4452 (at redshift z=1.26) and RXJ 0848.6+4453 (redshift z=1.27) . At the time of discovery, it was the most distant known supercluster with a comoving distance of 12.9 billion light years. Additionally, seven smaller groups of galaxies are associated with the supercluster. Through electromagnetic radiation and how it reacts with matter, we have been able to find three groupings of stars and two x-ray clusters within the Lynx.
The observation of the Lynx Supercluster has allowed other locations in proximity to be found. These locations are of special interest because of their high density, which has turned into the discovery of the seven smaller groups of galaxies mentioned above.
A study has been conducted between the clusters in the Lynx, to examine and compare their color and shift.
References
Galaxy superclusters
Lynx (constellation) | Lynx Supercluster | [
"Astronomy"
] | 253 | [
"Astronomical objects",
"Lynx (constellation)",
"Constellations",
"Galaxy superclusters"
] |
49,065,540 | https://en.wikipedia.org/wiki/Tapioca%20pearl | A tapioca pearl, also known as tapioca ball, is an edible translucent sphere produced from tapioca, a starch made from the cassava root. They originated as a cheaper alternative to sago in Southeast Asian cuisine. When used as an ingredient in bubble tea, they are most commonly referred to as pearls or boba. The starch pearls are typically in diameter. By adding different ingredients, like water, sugar, or some other type of sweetener like honey, tapioca pearls can be made to vary in color and in texture. Various forms of tapioca pearls include black, flavored, popping, mini, and clear. Tapioca pearls are commonly soaked in sugar syrup to make them sweet and chewy. In teas, they are often added for their texture, with the flavor being provided by the drink itself.
The pearls are known as sabudana in the Indian subcontinent; they are used for sweet and savory dishes, such as sabudana khichri. In Brazil, the pearls are cooked with wine or other liquid to add flavor and are called sagu.
History
Making jelly-like desserts from starch and using them in dessert dishes and drinks originated from Island Southeast Asia. Traditional versions of tapioca pearls made from native starch sources like palm hearts or glutinous rice include pearl sago, landang, and kaong. They are used in a wide variety of dishes and drinks like bilo-bilo, binignit, es campur, es doger, and halo-halo, among others. The introduction of cassava from South America during the colonial era added another starch source to Southeast Asian cuisine, resulting in cassava-based versions of Southeast Asian dishes that were formerly made from native starch sources. Among these are tapioca pearls, which originated as a cheaper alternative to pearl sago. They are virtually indistinguishable in taste and can be used interchangeably.
Pearl sago and tapioca pearls were introduced to Chinese cuisine via the Hokkien diaspora. They are popularly sold in "jelly tapioca pearls" (also known as "frog egg drinks") which are adaptations of Southeast Asian drinks and shaved ice desserts. They get their Mandarin name, "frog eggs", from their white appearance in the balls' centers after cooking. Vendors who sell the drink usually add syrup or creamer before serving, or serve it on top of shaved ice. In Taiwan, it is more common for people to refer to bubble tea as pearl milk tea (zhēn zhū nǎi chá, 珍珠奶茶) because originally, small tapioca pearls with a diameter were used. It was only when one tea shop owner—in an attempt to make his tea stand out—decided to use larger tapioca balls and chose a more provocative name, "boba", to represent the difference. In Chinese, the word boba, 波霸, is a combination of a word for bubble and a word for big, which, when found together, is slang for "big breasts" or "buxom lady". When used to describe the drink, the characters 波霸奶茶 directly translate to boba milk tea, and loosely to bubble milk tea. This translation is commonly used by English speakers and refers to the variant with tapioca pearls.
The making of tapioca balls was also introduced to Brazil (where cassava is native), where they are still known as sagu, despite being made from cassava and not sago palms. Sagu is used in a traditional dish known as sagu de vinho ("wine sago"), popular in the southern state of Rio Grande do Sul. It is usually mixed with sugar and red wine and served warm. It is also often added to tea drinks.
Popularity
Tapioca pearls have recently gained greater global popularity due to the spread of Taiwanese bubble tea, also called boba tea, across Europe and North America. McDonald's restaurants in Germany and Austria were temporarily selling the dessert beverage as part of their revamped McCafé menu in 2012.
Manufacturing
Tapioca pearls are derived as baked tapioca products, which are obtained from heat treatment of the moist cassava starch in shallow pans.
Preparation of wet flour
To create pearls, tapioca flour (also known as tapioca starch) is mixed with boiling water until a kneadable consistency is achieved. The dough is cut and rolled into a spherical shape. One method of achieving the correct shape is called the gangsor method. The starch is inserted into a long, cylindrical twill cloth bag and a jerking motion is used to toss the starch lumps back and forth. The lumps will become more firm and gain a more spherical shape. The process is repeated until the pearls have roughly become the desired size, then sorted according to size.
Another method is to feed the moist flour into open cylindrical pans, which rotate for a certain amount of time and at a specific speed to form the pearls.
Gelatinization
Traditionally, during heat treatment, the temperature is kept moderate so that only the surface layer of the lumps of the moist starch begins to gelatinize, and this process is described as gelatinization. One process of gelatinization is performed by placing the pearls inside shallow pans, which are then placed inside a brick oven. The pans are covered with a towel soaked in oil or fat to prevent burning the starch. While the pearls are heated over a moderate fire, it is stirred continuously with large forks to prevent burning. When this hand-baking process is applied to manufacture pearls, irregularly shaped beads may be obtained, inferior in color and in other qualities.
In order to produce first-rate products, the starch beads are poured onto plates in a thick layer, and the plates are slowly drawn through a tunnel charged with steam. In this way, uniform gelatinization is ensured.
Drying
During the gelatinization process, since moisture content does not change much, another drying stage is required to achieve the desired moisture content of 12%. Drying is done in a chamber dryer and when drying, it must have an initial temperature of below to avoid further gelatinization.
Freezing
Other than drying, freezing can also be used to preserve pearls before consumption. After gelatinization, the pearls are soaked in ice water to decrease the viscosity and enhance chewiness. If stored, pearls should be frozen using a quick freezing device, such as an air-blast freezer, or through an individual quick freezing process to prevent them from sticking together. One important note is that retrogradation happens quickest at near 0°C temperatures, which would lead to tougher pearls, so it is best to minimize the time that the pearls spend in that temperature range and freeze the pearls to lower temperatures quickly.
Preparation for consumption
The Consumers and food retail establishments can purchase raw tapioca starch and create their own pearls, or they can purchase partially cooked pearls, which have already gone through the gelatinization process. Raw tapioca pearls usually require 45 minutes of boiling whereas partially-cooked tapioca pearls require 30 minutes. To ensure a chewy texture, the pearls are then cooled for approximately 20 minutes. One can verify whether the pearls are ready to serve by taking a pearl and chewing it, making sure it is well-cooked all the way to the center.
In addition to the shorter cooking time, another benefit of partially cooked tapioca is that it lasts longer, with a shelf life of 8 months compared with the shelf life of 6 months for raw tapioca. Cooked tapioca pearls should only be kept for around 4–6 hours. When serving tapioca pearls, the pearls will harden once submerged in water and will eventually soften and lump together. Lumping of tapioca pearls can be avoided by stirring and adding sugar.
After the tapioca pearls are cooked, they should be strained through a colander and then rinsed to remove excess starch. Then, if they're to be used as something sweet, such as in bubble tea or as a dessert topping, the tapioca pearls are soaked in a sugar solution for ten minutes. The sugar will also help to prevent them from lumping. The only way to determine the quality of the tapioca pearls is by the texture. The pearls will all stick together if they are too soft and squishy. They will be too difficult to chew if they are too hard. There is a balance for tapioca being both chewy and firm. There is a Chinese term for this pronounced QQ. This is similar to the Italian term al dente describing pasta that is chewable, but not too soft.
Health and nutrition information
Tapioca starch consists primarily of carbohydrates. A 100-gram portion contains about 367 calories and 86.7 grams of carbohydrates. It provides no protein or fat and contains zero cholesterol or sodium. It also has no sugars and very little dietary fiber (3.3 grams per 100 grams).
Tapioca starch contains some essential minerals, such as 100 mg of calcium, 1 mg of iron, and 933 mg of potassium per 100 grams. This makes it a useful ingredient for those needing a gluten-free, nut-free, or grain-free option.
Additives
To support to the creation of tapioca pearls, some additives are used, especially during the tapioca flour making process.
Sulfuric acid is added as a bleaching agent and helps to speed up the process of making flour.
Aluminum sulfate is useful for increasing the viscosity of the flour.
Sulfur dioxide is used to separate the starch from other unwanted substances as well as acting as a bleaching agent, and regulating microbial and enzymatic reactions.
Chlorine (use is banned in many countries) helps to create a higher quality flour and also has disinfecting and bleaching properties.
The tables below list permitted additives in tapioca pearl products regulated under different regions.
Additives permitted as domestic or imported food
Philippines
Singapore
Taiwan
Environmental issues
Tapioca is not a natural product, as it is processed from cassava. See Manufacturing. There is an issue with tapioca because a large amount of water is needed in order to produce it. One factory reports that it uses around 60 m3 for one ton of tapioca starch just in the first step of processing. With this much water being used, properly disposing of the wastewater is a priority. Tapioca contains cyanide, and depending on whether the tapioca is made for human consumption or industrial purposes there will be less or more cyanide. The wastewater used to process the tapioca contains this cyanide and if the wastewater is leaked into bodies of water containing aquatic life, due to the contaminated water's low pH, there is a direct effect on fish and possibly other animals that live on the shores of the polluted water. Water pollution from tapioca manufacturing has been a problem in many countries in Southeast Asia.
Controversy
German researchers from University Hospital Aachen tested the tapioca pearls from an unnamed Taiwanese chain. According to the New York Daily News, the report showed that carcinogenic chemicals were found in the samples. Chemicals found included styrene, acetophenone, and brominated substances, which were not permitted as food additives. Another German study found carcinogenic PCBs, or polychlorinated biphenyls, in the starchy pearls as well.
But the German reports did not specify the amount of substances they found in the tapioca pearls, and were not published in peer-reviewed medical or scientific journals. That is saying the accuracy of the results are not ensured.
Phthalates are a class of chemicals added to plastics for the purpose of strengthening plastic's flexibility, durability, longevity and transparency. In 2011, the Canadian Food Inspection Agency warned of phthalate contamination in some food items imported from Taiwan. DEHP, a type of phthalates, was reportedly found in concentrated juice beverages, tea drinks, and other food supplements. This low cost substance had replaced regular food additives, which would normally be an emulsifier for the contents inside the drinks to generate a more attractive and natural appearance. Over-consumption of phthalates can lead to very serious negative health effects such as endocrine disruption, malformation of reproductive organs, infertility and abnormal neurodevelopment. The tolerable daily intake of DEHP is 0.05 mg/kg/day for a 70 kg body weight individual. Fortunately, the study showed that some beverages contain phthalates at levels that do not exceed the daily limit. In high concentrations, it could modify the product's appearance significantly as well.
In 2013, the Agri-Food and Veterinary Authority of Singapore recalled tapioca pearls from bubble tea shops after 11 kinds of Taiwanese starch additives that contained maleic acid were discovered. Maleic acid, when ingested, is known to induce kidney damage. An experiment done on dogs and rats also found kidney and liver damage when they were given daily doses of maleic acid for two years.
In June 2019, there was a case where a 14-year-old girl from China was admitted to the hospital after she described her stomach pain and constipation. After Dr. Zhang Louzhen, from the Zhuji People's Hospital, gave her a CT scan, he saw over one hundred small, grey spheres sitting in parts of her abdomen. The starch that tapioca pearls are made of, in combination of thickeners and other additives, when consumed in large amounts may lead to bowel obstruction.
See also
Arenga pinnata
Chondrus crispus
Agar
Helmipuuro
References
Food ingredients | Tapioca pearl | [
"Technology"
] | 2,854 | [
"Food ingredients",
"Components"
] |
49,065,762 | https://en.wikipedia.org/wiki/C5H4O | {{DISPLAYTITLE:C5H4O}}
The molecular formula C5H4O (molar mass: 80.08 g/mol, exact mass: 80.0262 u) may refer to:
Cyclopentadienone | C5H4O | [
"Chemistry"
] | 56 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
49,067,106 | https://en.wikipedia.org/wiki/Jack%20R.%20Norton | Jack Richard Norton (born May 5, 1945) is an American organometallic chemist and Professor at Columbia University. His research has focused on the studying the reactivity and properties of transition metal hydrides. He coauthored the textbook "Principles and Applications of Organotransition Metal Chemistry."
Education and career
Norton was born in Dallas, Texas in 1945. He received his B.A. from Harvard University in 1967 and was awarded his Ph.D. at Stanford in 1972 under the mentorship of James P. Collman. After a postdoctoral appointment with Jack Lewis, he was appointed assistant professor at Princeton University. He moved to Colorado State University in 1979, and again to Columbia University in 1997, where he remains Professor of Chemistry. From 1992-2003 he was an associate editor of Journal of the American Chemical Society
His laboratory demonstrated the possibility of dinuclear reductive elimination from transition metal alkyls and hydrides by comparing the mechanisms of reductive elimination from (H)2Os(CO)4, (H)(CH3)Os(CO)4, and (CH3)2Os(CO)4. His group later reported some of the first detailed pKa measurements of metal hydrides and demonstrated that the rates of protonation at transition metals can be quite slow. His group has also reported on the use of metal-hydride bonds as radical initiators of cyclization reactions.
In 2005 he received the ACS Award for Organometallic Chemistry and in 2013 the Cope Scholar Award
External links
Norton Research Group at Columbia
References
1945 births
Inorganic chemists
Living people
Harvard University alumni
Stanford University alumni | Jack R. Norton | [
"Chemistry"
] | 343 | [
"Inorganic chemists"
] |
49,067,304 | https://en.wikipedia.org/wiki/Ambush%20hypothesis | The ambush hypothesis is a hypothesis in the field of molecular genetics that suggests that the prevalence of “hidden” or off-frame stop codons in DNA selectively deters off-frame translation of mRNA to save energy, molecular resources, and to reduce strain on biosynthetic machinery by truncating the production of non-functional, potentially cytotoxic protein products. Typical coding sequences of DNA lack in-frame internal stop codons to avoid the premature reduction of protein products when translation proceeds normally. The ambush hypothesis suggests that kinetic, cis-acting mechanisms are responsible for the productive frameshifting of translational units so that the degeneracy of the genetic code can be used to prevent deleterious translation. Ribosomal slippage is the most well described mechanism of translational frameshifting where the ribosome moves one codon position either forward (+1) or backward (-1) to translate the mRNA sequence in a different reading frame and thus produce different protein products.
In respect to codon usage, the ambush hypothesis theorizes that there is a positive correlation between the use of a codon and the amount a codon contributes to hidden stops. Phylogenetic analyses of both the nuclear and mitochondrial genomes of all major taxonomic kingdoms suggests ubiquitous off-frame stop codon existence and a positive correlation between the usage frequency of a codon and the number of ways a codon can contribute to hidden stop codons in different translational reading frames.
Combinatorics have been used across genetic codes to determine how each in-frame codon can potentially contribute to stop codons in off-frame contexts. The standard genetic code only contains 20 codons that cannot become stop codons in a frameshifted ribosomal environment (-1 frameshift: 42, +1 frameshift: 28) and 127 out of the 400 (31.75%) possible adjacent amino acid combinations in the vertebrate mitochondrial code creates an off-frame stop codon. This suggests that substitutions and synonymous codon usage are not neutral and that selective pressures might have readjusted codon assignments to increase the frequencies of those that can be used as hidden stops.
Observations that the number of off-frame stop codons is positively correlated with the expression level of a gene support the ambush hypothesis by increasing translational regulation (hidden stop frequency) to discourage off-frame reading in genes that are expressed at a high level. The positive correlation indicates that the off-frame translation of larger genes with higher expression levels likely costs a cell more energy, resources, and pathway efficiency than translating smaller, more rare genes in a shifted reading frame. Off-frame stop codon frequency is negatively correlated with gestation time in primates and though there are many factors that link molecular translational efficiency to the rate of morphogenesis, these findings suggests that not only individual cells but entire organisms may benefit from the development of hidden stop codons to effectively halt off-frame synthesis.
The ambush hypothesis is challenged by recent observations that off-frame stop codons are directly correlated with the GC content in the genome because stop codons are GC-poor. Morgens et al. 2013 argues that previous research concerning the ambush hypothesis has relied on codon usage data which is representative of the GC content of an organism and thus not appropriate to evaluate the selective effect of off-frame stop codons.
References
Molecular genetics
Gene expression | Ambush hypothesis | [
"Chemistry",
"Biology"
] | 692 | [
"Gene expression",
"Molecular genetics",
"Cellular processes",
"Molecular biology",
"Biochemistry"
] |
49,067,317 | https://en.wikipedia.org/wiki/List%20of%20protein-ligand%20docking%20software | The number of notable protein-ligand docking programs currently available is high and has been steadily increasing over the last decades. The following list presents an overview of the most common notable programs, listed alphabetically, with indication of the corresponding year of publication, involved organisation or institution, short description, availability of a webservice and the license. This table is comprehensive but not complete.
References
External links
Structural bioinformatics software
Molecular modelling software
Computational chemistry software
protein-ligand docking | List of protein-ligand docking software | [
"Chemistry",
"Technology"
] | 97 | [
"Molecular modelling software",
"Lists of software",
"Computational chemistry software",
"Chemistry software",
"Computing-related lists",
"Molecular modelling",
"Computational chemistry"
] |
49,067,628 | https://en.wikipedia.org/wiki/M%C3%A9canique%20analytique | Mécanique analytique (1788–89) is a two volume French treatise on analytical mechanics, written by Joseph-Louis Lagrange, and published 101 years after Isaac Newton's Philosophiæ Naturalis Principia Mathematica.
Treatise
It consolidated into one unified and harmonious system, the scattered developments of contributors such as Alexis Clairaut, Jean le Rond d'Alembert, Pierre-Simon Laplace, Leonhard Euler, and Johann and Jacob Bernoulli in the historical transition from geometrical methods, as presented in Newton's Principia, to the methods of mathematical analysis. The treatise expounds a great labor-saving and thought-saving general analytical method by which every mechanical question may be stated in a single differential equation.
Lagrange wrote that this work was entirely new and that his intent was to reduce the theory and the art of solving mechanics problems to general formulae, providing all the equations necessary for the solution of each problem. He stated that:No diagrams will be found in this work. The methods that I explain require neither geometrical, nor mechanical, constructions or reasoning, but only algebraical operations in accordance with regular and uniform procedure. Those who love Analysis will see with pleasure that Mechanics has become a branch of it, and will be grateful to me for having thus extended its domain.
Ernst Mach describes the work as follows:Analytic mechanics... was brought to the highest degree of perfection... Lagrange's aim is... to dispose, once and for all, of the reasoning necessary to resolve mechanical problems, by embodying as much as possible of it in a single formula. This he did. Every case... can now be dealt with by a very simple... schema; and whatever reasoning is left is performed by purely mechanical methods. The mechanics of Lagrange is a stupendous contribution to the economy of thought.
Publication history
The work was first published in 1788 (volume 1) and 1789 (volume 2). Lagrange issued a substantially enlarged second edition of volume 1 in 1811, toward the end of his life. His revision of volume 2 was substantially complete at the time of his death in 1813, but was not published until 1815.
The second edition of 1811/15 has been translated into English, and is available online at archive.org.
References
External links
English translation of the 1811 edition
Mathematical physics
Physics books
Mathematics books | Mécanique analytique | [
"Physics",
"Mathematics"
] | 503 | [
"Applied mathematics",
"Theoretical physics",
"Mathematical physics"
] |
49,068,411 | https://en.wikipedia.org/wiki/Onesimus%20%28Bostonian%29 | Onesimus (late 1600s–1700s) was an African (likely Akan) man who was instrumental in the mitigation of smallpox in Boston, Massachusetts.
He introduced his enslaver, Puritan clergyman Cotton Mather, to the principle and procedure of the variolation method of inoculation, which prevented smallpox and laid the foundation for the development of vaccines.
After a smallpox outbreak began in Boston in 1721, Mather proliferated Onesimus's knowledge to advocate for inoculation in the population. This practice eventually spread to other colonies.
Recognition for Onesimus's contributions to medical science came in 2016, when the Boston magazine declared him among the 100 Best Bostonians of All Time. Historian Ted Widmer of CUNY's Macaulay Honors College noted that "Onesimus reversed many of [the colonists'] traditional racial assumptions... [h]e had a lot more knowledge medically than most of the Europeans in Boston at that time."
Early life and enslavement
Onesimus's name at birth and place of birth are unknown with certainty. He was first documented as living in the colonies in 1706, having been brought to North America as an enslaved person. In December of that year, he was given as a gift by a church congregation to Cotton Mather, their Puritan minister of North Church, as well as a prominent figure in the Salem Witch Trials. Mather renamed him after a first-century AD enslaved person mentioned in the Bible. The name, "Onesimus" means "useful, helpful, or profitable".
Mather referred to the ethnicity of Onesimus as "Guaramantee", which may refer to the Coromantee (also known as Akan people of modern Ghana).
Mather saw Onesimus as highly intelligent and educated him in reading and writing with the Mather family (for context, according to biographer Kathryn Koo, at that time, literacy was primarily associated with religious instruction, and writing as means of note-taking and conducting business).
Inoculation advocacy and controversy
In 1716 or shortly before, Onesimus had described to Mather the process of inoculation that had been performed on him and others in his society in Africa (as Mather reported in a letter): "People take Juice of Small-Pox; and Cut the Skin, and put in a drop." In the book, African Medical Knowledge, the Plain Style, and Satire in the 1721 Boston Inoculation Controversy, Kelly Wisecup wrote that Onesimus is believed to have been inoculated at some point before being sold into slavery or during the slave trade, as he most likely traveled from the West Indies to Boston. The variolation method of inoculation was long practiced in Africa among sub-Saharan people. The practice was widespread among enslaved colonial people from many regions of Africa and, throughout the slave trade in the Americas, slave communities continued the practice of inoculation despite regional origin.
Mather followed Onesimus's medicinal advice because, as Margot Minardi writes, "inferiority had not yet been indelibly written onto the bodies of Africans." Additionally, Mather believed that disease, specifically smallpox, was a spiritual and physical punishment, so he saw a cure as "God's providential gift", as well as a means of receiving recognition from New England society and re-establishing the influence of religious figures in politics.
When Boston experienced a smallpox outbreak in 1721, Mather promoted inoculation as protection against it, citing Onesimus and African folk medicine as the source of the procedure. His advocacy for inoculation met resistance from those suspicious of African medicine. Doctors, ministers, laymen, and Boston city officials argued that the practice of inoculating healthy individuals would spread the disease and that it was immoral to interfere with the working of divine providence. Also, Mather was ridiculed publicly for relying on the testimony of an enslaved person. It was commonly anticipated that enslaved Africans would attempt an overthrow of white society; therefore, the medicinal wisdom of Onesimus was met with severe mistrust and assumed to be a ploy to poison white citizens. The Acts and Resolves passed in Boston, which included race-based punishments and codes to prevent enslaved or servant uprisings (because Bostonians feared conspiracy and conflict), showed a society skeptical of African medicine.
Nonetheless, a physician, Zabdiel Boylston, carried out the method Onesimus had described, which involved sticking a needle into a pustule from an infected person's body and scraping the infected needle across a healthy person's skin. Dr. Boylston first inoculated his six-year-old son and two of his slaves. Two hundred eighty individuals were inoculated during the 1721–22 Boston smallpox epidemic. The population of 280 inoculated patients experienced only six deaths (approx. 2.2 percent), compared to 844 deaths among the 5,889 non-inoculated smallpox patients (approx. 14.3 percent). An inscription on his tomb incorrectly identifies Boylston as the "first" to have introduced the practice of inoculation into America.
Personal life
Onesimus earned independent wages and afforded a household for himself and the wife he took while serving the Mather family. It is unclear whether his wife was a free woman. They had two children, both of whom died before they were ten years old. His son, Onesimulus, died in 1714. Katy, his second child, died due to consumption. Culturally, Puritans believed that children "belonged to God", and parents were admonished to be prepared for the loss of a child. Likely, this belief was connected to the fact that, between 1640 and 1759, one in four children died before age ten.
After the deaths of his children, Mather attempted to convert Onesimus to Christianity, overtures Onesimus rejected. Mather saw his inability to convert the man he enslaved as his failure as a Puritan evangelist and head of his household, as Onesimus' refusal was supposed to bring God's displeasure on the Mather family. Onesimus was catechized in his free time as Mather attempted to convert him to Christianity. Onesimus' refusal to convert led to Mather's unhappiness with his presence in the household. Mather's diary reports "stubborn behavior" from Onesimus following the death of his children.
In 1716, Onesimus attempted to buy his freedom from Mather, raising funds to "purchase" another enslaved man named Obadiah to take his place. Mather placed conditions on his release however, requiring that he remain available to perform work in the Mather household at their command and return five pounds that Mather claimed that Onesimus had stolen from him.
Legacy
Boston and London, in 1726 and 1722, respectively, performed trials on citizens, and, on average, inoculation decreased the mortality rate from 17% to 2% of the infected population.
In 1796, the inoculation methodology Onesimus introduced was replaced by Edward Jenner's development of vaccination for smallpox and cowpox. Thereafter, vaccination became compulsory in Wales and England, and variolation was banned for its side effects. In 1980, the World Health Organization declared that smallpox had been completely eradicated due to global immunization efforts, making it the first and only human infectious disease for which this has been accomplished.
See also
Jane Minor, African-American healer and slave emancipator
Footnotes
References
Works cited
People from colonial Boston
People from North End, Boston
17th-century births
18th-century deaths
Smallpox eradication
Vaccination advocates
18th-century American slaves | Onesimus (Bostonian) | [
"Biology"
] | 1,572 | [
"Vaccination",
"Vaccination advocates"
] |
49,068,504 | https://en.wikipedia.org/wiki/Tethersonde | A tethersonde is a type of radiosonde used in atmospheric science for atmospheric sounding. Tethersondes are attached to fixed or tethered balloons via a separate tether and can be moved up and down the tether to obtain multiple atmospheric readings.
References
Meteorological instrumentation and equipment
fr:Radiosonde#Radiosonde captive | Tethersonde | [
"Technology",
"Engineering"
] | 71 | [
"Meteorological instrumentation and equipment",
"Measuring instruments"
] |
49,068,749 | https://en.wikipedia.org/wiki/Margin%20at%20risk | The Margin-at-Risk (MaR) is a quantity used to manage short-term liquidity risks due to variation of margin requirements, i.e. it is a financial risk occurring when trading commodities. It is similar to the Value-at-Risk (VaR), but instead of simulating EBIT it returns a quantile of the (expected) cash flow distribution.
To do so, MaR requires (1) a currency, (2) a confidence level (e.g. 90%) and (3) a holding period (e.g. 3 days).
The idea is that a given portfolio loss will be compensated by a margin call by the same amount.
The MaR quantifies the "worst case" margin-call and is only driven by market prices.
See also
Liquidity at risk
Value at risk
Profit at risk
Earnings at risk
Cash flow at risk
References
Mathematical finance
Financial_risk_modeling
Monte Carlo methods in finance
Credit risk | Margin at risk | [
"Mathematics"
] | 196 | [
"Applied mathematics",
"Mathematical finance"
] |
49,069,031 | https://en.wikipedia.org/wiki/Canadian%20Medical%20and%20Biological%20Engineering%20Society | The Canadian Medical and Biological Engineering Society (CMBES) is a technical society representing the biomedical engineering community in Canada. CMBES is supported by its membership which consists of biomedical engineers, biomedical engineering technologists and students. CMBES also hosts an annual conference and regular webinars. It produces a number of publications including the Clinical Engineering Standards of Practice and a Newsletter. The Society's aims are twofold: scientific and educational: directed toward the advancement of the theory and practice of medical device technology; and professional: directed toward the advancement of all individuals in Canada who are engaged in interdisciplinary work involving engineering, the life sciences and medicine.
Conference
The first Canadian Medical and Biological Engineering Conference was held September 8 and 9, 1966 in Ottawa, Ontario. CMBES continues to host an annual conference including sponsor seminars, technical paper presentations including peer-reviews, a conference proceedings, affiliation with Journal of Medical and Biological Engineering, vendor exhibit of current medical devices, a continuing education program, workshops, symposia, and networking opportunities.
The location of the conference rotates between Canadian cities every year. Occasionally the conference is held in conjunction with like organisations. Partnerships in the past have included: IEEE Engineering in Medicine and Biology Society (EMBS), Festival of International Conferences on Caregiving, Disability, Aging and Technology (FICCDAT) and the International Union for Physical and Engineering Sciences in Medicine (IUPESM).
In 2015, the CMBES and IUPESM hosted the World Congress on Medical Physics & Biomedical Engineering, in Toronto Ontario, Canada.
Annual conference proceedings are published online under International Standard Serial Number (ISSN) 2371-9516.
International Outreach
The objective of the Committee is to pursue and develop opportunities for CMBES members to participate in volunteer programs to support Clinical Engineering initiatives and Health Technology Management in developing countries.
Clinical Engineering Standards of Practice
The CMBES Clinical Engineering Standards of Practice for Canada (CESOP) was first published in 1998 and revised in 2007 and 2014. These guidelines outline criteria for health care institutions on the management of medical devices, promote the professional development of its members, and outline the education and certification requirements for clinical engineers and biomedical engineering technologists and technicians.
Affiliations
CMBES is a member society of the Engineering Institute of Canada and the International Federation for Medical and Biological Engineering. They also have affiliation agreements with the Association des physiciens et ingénieurs biomédicaux du Québec and Atlantic Canada Clinical Engineering Society.
Awards
Awards are bestowed to recipients annually, upon recommendation of the awards committee to the CMBES Executive. Award categories include:
Outstanding Canadian Biomedical Engineer
Outstanding Canadian BMET
Early Career Achievement
Special Membership Recognition/Honours
Special Membership status is awarded only to distinguished individuals who have made significant contributions to the profession of biomedical engineering and to the Society in particular.
Fellow
Emeritus
Honorary
The CMBES has bestowed the fellow award on some of the following notable Canadian individuals: James McEwen (engineer), Monique Frize, Morris Milner, and John Alexander Hopps amongst others.
Notes and references
Engineering societies based in Canada
Biomedical engineering | Canadian Medical and Biological Engineering Society | [
"Engineering",
"Biology"
] | 617 | [
"Biological engineering",
"Medical technology",
"Biomedical engineering"
] |
49,070,948 | https://en.wikipedia.org/wiki/Maxicell | Maxicell is a system for identifying plasmid-encoded proteins that was developed by Sancar, AM Hack, and WD Rupp. The method uses a mutant strain of the bacterium Escherichia coli that is defective in repairing DNA damage. Irradiating the mutant cells with UV light leads to degradation of the bacterial chromosome. Plasmids in the cells mostly escape the UV-induced damage because of their small size. Proteins encoded by genes on the bacterial chromosome will no longer be synthesized, while proteins encoded by genes on the plasmid DNA molecules will continue to be made. The addition of radioactively-labeled amino acids following the UV treatment allows the plasmid-encoded proteins to be specifically visualized, because proteins synthesized prior to the UV treatment will not contain the radioactive label. The method was used for amplification of photolyase in Escherichia coli.
References
DNA
Escherichia coli | Maxicell | [
"Biology"
] | 194 | [
"Model organisms",
"Escherichia coli"
] |
49,071,124 | https://en.wikipedia.org/wiki/Pyrrhulomyces%20astragalinus | Pyrrhulomyces astragalinus, commonly known as the pinkish-orange pholiota, is a species of fungus in the family Strophariaceae. It was first described scientifically in 1821 by Elias Magnus Fries as a species of Agaricus. Rolf Singer transferred it to the genus Pholiota in 1951 and the species was transferred to its present genus in 2020 by E.J. Tian & Matheny. The fruitbodies of the fungus have pinkish-orange caps measuring in diameter. The flesh is orange, blackening in age, with a bitter taste. They produce a reddish-brown spore print, causing it to be placed in its genus rather than Hypholoma, which it resembles. The spores are oval to elliptical, smooth with thin walls, and measure 5–7 by 4–4.5 μm. In North America, the fungus is found in the United States and Canada. In Europe, it has been recorded from France, Sweden, and Switzerland. Its mushrooms usually grow singly or in small clusters, sometimes on conifer logs.
Though nonpoisonous, the species is regarded as inedible.
References
Strophariaceae
Fungi described in 1821
Fungi of Europe
Fungi of Canada
Fungi of the United States
Inedible fungi
Taxa named by Elias Magnus Fries
Fungi without expected TNC conservation status
Fungus species | Pyrrhulomyces astragalinus | [
"Biology"
] | 280 | [
"Fungi",
"Fungus species"
] |
49,072,185 | https://en.wikipedia.org/wiki/Lactobacillus%20jensenii | Lactobacillus jensenii is a lactic acid bacteria species in the genus Lactobacillus.
It is one of the four main species of Lactobacillus considered to be the major part of the vaginal flora, along with Lactobacillus crispatus, Lactobacillus gasseri, and Lactobacillus iners.
L. jensenii is sometimes used in producing fermented foods.
Lactobacillus jensenii produces enzymes that cause hydrolase release from the liver. Hydrolase aids in the digestion of food in the upper gastrointestinal tract.
Lactobacillus jensenii and other Lactobacillus species that produce lactic acid, (most notably L. crispatus), have been correlated with a decreased rate of bacterial vaginosis, gonorrhea- and HIV-acquisition and pelvic inflammatory disease. A stable colonization with these species, as opposed to dominantly L. iners, is associated with better reproductive outcomes, e.g. a decreased rate of preterm birth.
Discovery
Lactobacillus jensenii was discovered by F. Gasser, M. Mandel, and M. Rogosa in 1969. Although sharing many characterization criteria, L. jensenii differed from the similar Lactobacillus leichmannii in a gel electrophoresis analysis of their respective lactic dehydrogenases. The species was named in honour of Sigurd Orla-Jensen, a Danish microbiologist and a pioneer of biotechnology.
Characterization
Lactobacillus jensenii is Gram-positive, rod-shaped, negative for catalase and oxidase, and anaerobic. The organism can grow on blood agar.
Morphology
Colonies of L. jensenii are circular, colorless, small, and translucent.
Infection
Bloodstream infection by Lactobacilli is rare but often fatal, with 30% of endocarditis cases caused by the genus resulting in patient mortality. While L. jensenii takes advantage of nonimmunocompetence in patients, immunocompetent cases have also been observed.
Treatment
In the rare occurrence of infection, L. jensenii can be treated with teicoplanin and meropenem.
References
External links
Type strain of Lactobacillus jensenii at BacDive - the Bacterial Diversity Metadatabase
Lactobacillaceae
Bacteria described in 1999
Microbiomes | Lactobacillus jensenii | [
"Environmental_science"
] | 508 | [
"Microbiomes",
"Environmental microbiology"
] |
49,072,305 | https://en.wikipedia.org/wiki/Methane%20functionalization | Methane functionalization is the process of converting methane in its gaseous state to another molecule with a functional group, typically methanol or acetic acid, through the use of transition metal catalysts.
In the realm of carbon-hydrogen bond activation and functionalization (C-H activation/functionalization), many recent efforts have been made in order to catalytically functionalize the C-H bonds in methane. The large abundance of methane in natural gas or shale gas deposits presents a large potential for its use as a feedstock in modern chemistry. However, given its gaseous natural state, it is quite difficult to transport economically. Its ideal use would be as a raw starting material for methanol or acetic acid synthesis, with plants built at the source to eliminate the issue of transportation. Methanol, in particular, would be of great use as a potential fuel source, and many efforts have been applied to researching the feasibilities of a methanol economy.
The challenges of C-H activation and functionalization present themselves when several factors are taken into consideration. Firstly, the C-H bond is extremely inert and non-polar, with a high bond dissociation energy, making methane a relatively unreactive starting material. Secondly, any products formed from methane would likely be more reactive than the starting product, which would be detrimental to the selectivity and yield of the reaction.
The main strategy currently used to increase the reactivity of methane uses transition metal complexes to activate the carbon-hydrogen bonds. In a typical C-H activation mechanism, a transition metal catalyst coordinates to the C-H bond to cleave it, and convert it into a bond with a lower bond dissociation energy. By doing so, the product can be used in further downstream reactions, since it will usually have a new functional group attached to the carbon. It is also important to note the difference between the terms "activation" and "functionalization," since both terms are often used interchangeably, but should be held distinct from each other. Activation refers to the coordination of a metal center to the C-H bond, whereas functionalization occurs when the coordinated metal complex is further reacted with a group "X" to result in the functionalized product.
Methane activation
The four most common methods of transition metal catalyzed methane activation are the Shilov system, sigma bond metathesis, oxidative addition, and 1,2 addition reactions.
The Shilov system involves platinum based complexes to produce metal alkyls. It was first discovered when a hydrogen-deuterium exchanged was observed in a deuterated solution with the platinum tetrachloride anion. Shilov et al. then was able to catalytically convert methane into methanol or methyl chloride when a Pt(IV) salt was used as a stoichiometric oxidant. The process is simplified down into three main steps: (1) C-H activation, (2) a redox reaction to form an octahedral intermediate, followed by (3) the formation of the carbon-oxygen bond to form methanol ().
Sigma bond metathesis involves the formation of new C-H and metal-carbon bonds, where the metals are typically in the d0 configuration. Starting with a metal alkyl, a C-H bond coordinates with the metal complex via sigma bonding. A four-member transition state is created, where a new metal-carbon bond is formed, and the former C-H linkage is broken ().
In oxidative addition, the metal center's oxidation state increases by 2 units during the process. First, the metal center coordinates with a sigma C-H bond to form an intermediate called a sigma-methane complex. The C-H linkage is then broken, as the metal becomes covalently bonded each to the carbon and the hydrogen ().
Similar to sigma bond metathesis is the 1,2 addition reaction, where a four-membered transition state is also formed. However, a polarized double or triple metal-ligand bond is required in order to favor the formation of the desired product ().
Methane functionalization
Once the C-H bond of methane is activated by bonding to a transition metal complex, the net functionalization of the alkyl metal complex into another hydrocarbon containing a functional group is actually much harder to achieve. In general, alkanes of various lengths have typically been functionalized by a number of more commonly known reactions: electrophilic activation (Shilov system, see above), dehydrogenation, borylation, hydrogen-deuterium exchange, and carbene/nitrene/oxo insertion. The functionalization of methane in particular has been reported in four different methods that use homogeneous catalysts rather than heterogeneous catalysts. Heterogeneous systems, using copper- and iron exchanged Zeolite, are also investigated. In these systems, reactive oxygen species such as Alpha-Oxygen are generated which can perform a hydrogen atom abstraction.
The Catalytica system
In 1993, Periana et al. reported a synthesis of methyl bisulfate from methane using a mercury catalyst at 180 °C. Mercuric bisulfate activates methane electrophilically to form a methyl-complex, which then reacts with sulfuric acid to produce methyl bisulfate. The resulting mercury complex Hg2(OSO3)2 is re-oxidized by sulfuric acid to regenerate the catalyst and restart the catalytic cycle ().
This method of functionalizing methane preceded the 1998 discovery by the same group of the so-called Catalytica system, the most active cycle to date in terms of turnover rate, yields, and selectivity. Performing the reaction in sulfuric acid at 220 °C means that the catalyst must be able to withstand these harsh conditions. A platinum-bipyrimidine complex serves as the catalyst. The mechanism for this system is similar to the one described above, where methane is first activated electrophilically to form a methyl-platinum intermediate. The Pt(II) complex is then oxidized to Pt(IV) as two sulfuric acid groups are added to the complex. The reductive elimination of methyl bisulfate transforms the Pt(IV) species back to Pt(II) to regenerate the catalyst ().
In a hypothetical combined process, the Catalytica system could be used in a net conversion of methane to methanol. The methyl bisulfate produced in the cycle could be converted to methanol by hydrolysis, and the sulfur dioxide generated could be converted back to sulfuric acid.
Conversion to acetic acid
Periana's group was also able to convert methane into acetic acid using similar conditions to the Catalytica system. Palladium(II) salts were used in this process, and the products formed were a mixture of methanol and acetic acid, along with side products of carbon monoxide and possibly carbon dioxide due to over-oxidation. The mechanism of reaction involves another electrophilic activation of methane, and when carbon monoxide is incorporated, the acetic acid derivative is generated through its activation to an acyl intermediate ().
Another example of acetic acid synthesis was demonstrated by Pombeiro et al., which used vanadium-based complexes in trifluoroacetic acid with peroxodisulfate as the oxidant. The proposed mechanism involves a radical mechanism, where methane is the methyl source and trifluoroacetic acid is the carbonyl source. Minor side products were formed, including methyltrifluoroacetate and methylsulfate.
Dehydrogenative silation and olefin hydromethylation
T. Don Tilley and coworkers were able to use the process of sigma-bond metathesis to design catalytic systems that work by the formation of carbon-carbon bonds. They first demonstrated an example using a scandium-based system, where methane is dehydrogenated and silated. Starting from phenyl silane, methane pressure converts it into Ph2MePhH using a Cp*ScMe catalyst. The scandium complex then transfers the methyl group to the silane by sigma-bond metathesis to form the product and the Cp*2ScH intermediate. The favorable formation of hydrogen gas combined with methane will regenerate the methyl complex from the hydride derivative ().
Cp*2ScMe was also used as a catalyst in the formation of isobutane by adding methane to the double bond of propene. This was achieved when propene and methane were combined in the presence of the scandium catalyst and heated to 80 °C.
Carbene insertion
Carbene insertion use a different strategy for the functionalization of methane. A strategy using metallocarbenes has been shown with several linear and branched alkanes with rhodium, silver, copper, and gold-based catalysts. With a carbene ligand attached to a metal center, it can be transferred from the coordination sphere and inserted into an activated C-H bond. In this case, there is no interaction between the metal center and the alkane in question, which separates this method from the other methods mentioned above. The general mechanism for this cycle begins with the reaction of an electron-poor metal center with a diazocompound to form a metallo-carbene intermediate. In order for this reaction to occur, the diazocompound must be very electrophilic, since the C-H bond is such a poor nucleophile as well as being an unactivated alkane. The reaction then proceeds in a concerted manner, where the C-H bond of the incoming molecule coordinates with the carbene carbon of the metallocarbene complex. The hydrocarbon then dissociates from the metal center to regenerate the catalyst and free the newly formed carbon-carbon bond ().
This route is very successful for higher order alkanes due to the fact that there is no formation of strong metal-carbon or metal-hydrogen bonds that could prevent any intermediates from reacting further. The reactions also take place in room temperature under mild conditions. However, when applying this method to methane specifically, the gaseous nature of methane requires an appropriate solvent. Reactions with other alkanes usually have the alkane in question be the solvent itself; however, any C-H bond with a lower BDE or higher polarity than methane will react first and prevent methane functionalization. Therefore, Pérez, Asensio, Etienne, et al. developed a solution to use supercritical carbon dioxide as the solvent, which is formed under the critical pressure of 73 bar and a temperature of 31 °C. In these conditions, scCO2 behaves as a liquid, and since fluorinated compounds can dissolve easily in scCO2, highly fluorinated silver-based catalysts were developed and tested with methane and ethyl diazoacetate. However, under the reaction conditions, only 19% yield of ethyl propionate was able to be achieved. The reaction depends on a delicate balance between methane pressure and catalyst concentration, and consequently more work is being done to further improve yields.
References
Organometallic chemistry
Organic chemistry
Chemistry
Methane | Methane functionalization | [
"Chemistry"
] | 2,309 | [
"Greenhouse gases",
"Organometallic chemistry",
"Methane",
"nan"
] |
49,072,341 | https://en.wikipedia.org/wiki/F-block%20metallocene | In organometallic chemistry, f-block metallocenes are a class of sandwich compounds consisting of an f-block metal and a set of electron-rich ligands such as the cyclopentadienyl anion.
History
The first prepared and well-characterized f-block metallocenes were the tris(cyclopentadienyl) lanthanide complexes, (C5H5)3Ln (Ln = La, Ce, Pr, Nd, Sm and Gd). However, their significance is limited more to their existences and structures than to their reactivity. The cyclopentadienyl ligands of f-block metallocenes were considered as inert ancillary ligands, only capable of enhancing their stability and solubility, but not their reactivity. In addition, only late and small metals in the lanthanide series, i.e., elements from Sm to Lu, are trivalent metallocene complexes, [(C5H5)2LnZ]n In 1980, the pentamethylcyclopentadienyl ligand, C5Me, was introduced to prepare the lanthanide complexes with all metals in the series. Apart from improving the stability and solubility of the complexes, it was demonstrated to participate in organometallic reactions. Subsequently, William J. Evans and his coworkers successfully isolated (C5Me5)2Sm(THF)2 and (C5Me5)2Sm, making a breakthrough in f-block metallocenes, since both of these two organosamarium(II) complexes were unexpectedly found to participate in the coordination, activation and transformation of a variety of unsaturated compounds, including olefins, dinitrogen, internal alkynens, phosphaalkynes, carbon monoxide, carbon dioxide, isonitriles, diazine derivatives, imines and polycyclic aromatic hydrocarbons (PAHs). Moreover, due to its strong reducing potential, it was used to synthesize [(C5Me5)2Sm(μ-H)]2 and other trivalent f-block element complexes. Subsequently, tris(pentamethylcyclopentadienyl) lanthanide complexes, (C5Me5)3Ln, and their relevant complexes were synthesized from Sm2+ complexes. These metallocenes included (C5Me5)3Sm, [(C5H3(SiMe3)2]3Sm, (C5Me5)2Sm(C5H5), [(C5Me5)2Sm]2(μ-C5H5). Later, one tris(pentamethylcyclopentadienyl) f-element halide complex, (C5Me5)3UCl, was successfully isolated as the intermediate of the formation of (C5Me5)2UCl2. It is worthy mentioning that (C5Me5)3UCl has a very similar structure as (C5Me5)3U and its uranium-chloride bond (2.90 Å) is relatively longer than the uranium-chloride bonds of other analogues. Its existence also indicates that the larger f-block elements are capable of accommodating additional ligands in addition to the three cyclopentadienyl ligands resulting in the isolation of the following complexes: (C5Me5)3UF, (C5H3(TMS)2)3Th and (C5Me5)3ThH.
Synthesis
I. the synthesis of the first f-block metallocenes is described by following equation:
II. Preparation of (C5Me5)3Sm:
(i) the first (C5Me5)3Sm was prepared via exploratory Sm2+ chemistry with cyclooctatetraene:
(ii) Similar to method (i), (C5Me5)3Sm can be efficiently synthesized from a Sm2+ precursor and (C5Me5)2Pb:
In this pathway, (C5Me5)2Sm(OEt2) is used since it is more readily available than (C5Me5)3Sm and does not react THF.
(iii) additionally, (C5Me5)3Sm can also be prepared from trivalent precursors, without ring opening THF.
This solvated cation route generally allows the preparation of all (C5Me5)3Ln complexes since [(C5Me5)3LnH]x is known for all lanthanide elements.
An alternative unsolvated cation pathway prohibits THF during the reaction since (C5Me5)3Sm can ring open THF.
III. Generally, in order to synthesize (C5Me5)3M, the starting materials and the reaction conditions require optimizing to ensure (C5Me5)3M is the most favored product. In addition, compounds capable of reacting with (C5Me5)3M, such as THF, nitriles or isonitriles, should be avoided. Therefore, the following routes are possible options:
(i) For M=Ln including La, Ce, Pr, Nd and Gd, unsolvated cation route is preferred since [(C5Me5)2LnH]x complexes are too reactive.
Notably, the synthesis of (C5Me5)3La and (C5Me5)3Ce requires the usage of silylated glassware since they are easily oxidized.
(ii) For M=actinide like U, solvated cation route can be used.
IV. Synthesis of (C5Me5)3MZ with Z=X, H, etc.
Reactivity
Unlike d-block elements, f-block elements do not follow 18-electron rule due to their f-orbitals. The following complexes, (C5H4SiMe3)3Ln, have extremely negative reduction potentials of -2.7 to -3.9 Volts versus the standard hydrogen electrode (NHE). Furthermore, in comparison with d-orbitals of transition metals, the radial extension of their 4f-orbitals are really small and limited, which greatly reduces the orbital effects. More specifically, its 4fn electron configurations have almost no effect on its chemical reactivity and its electrostatic interactions require optimizing through ligand geometries. Moreover, the reactivity of the f-block element complexes relies heavily on their sterics. In other words, a sterically saturated structure offers the best stability, and so, both ligand size or metal size can be altered to modify the reactivity. These special properties allow the following reactions to occur.
Alkyl-like reactivity
Like alkyl group, the electron-rich ligand of f-block metallocenes can act as a nucleophile during organometallic reactions. For example, they can polymerize olefins, and participate in ring opening polymerizations, etc.
Ligand cleavage
Especially in the presence of Lewis acids like B(C6F5)3 or Al2Me6, the Cp and other similar ligands can be removed in the following way.
Insertions
The f-block metallocenes are able to undergo insertion reactions of compounds like carbon monoxide, nitriles or isocyanates.
Redox chemistry
Ordinary reductions
Since f-block metallocenes are very electron-rich, they tend to lose one electron and a pentamethylcyclopentadienyl ligand.
Sterically induced reduction (SIR)
Sterically crowded complexes like (C5Me5)3Sm are able to provide strong reductivity and so this type of reaction was named as SIR. Due to the strong steric hindrance, one ligand cannot bind to the metal center at the ideal distance and so the complex is not stable. Thus, the anion is more inclined to become oxidized and leave the complex, resulting in a highly reducing metal complex.
References
Organometallic compounds
Sandwich compounds | F-block metallocene | [
"Chemistry"
] | 1,704 | [
"Inorganic compounds",
"Organometallic compounds",
"Sandwich compounds",
"Organic compounds",
"Organometallic chemistry"
] |
49,072,349 | https://en.wikipedia.org/wiki/Tail%20biting%20in%20pigs | Tail biting in pigs is an abnormal behavior whereby a pig uses its teeth to bite, chew or orally manipulate another pigs's tail. Tail biting is used to describe a range in severity from light manipulation of the tail to physically harming the tail, causing infection, amputation or even harming areas surrounding the tail. Tail biting typically occurs under the following conditions: indoor facility with a high density of pigs housed in a confined area (like a pen); lack of a substrate material; poor ventilation system, or poor feed quality and accessibility.
There are three types of tail biting: two-stage, sudden forceful, and obsessive. The type of tail biting is based on the behaviors of each the biter and victim, physical consequences of the bite, and conditions under which the biting happens. A common cause of tail biting is due to pigs feeling stressed or discomfort and are looking for something to divert their attention. Some other causes of tail biting involve possible breed predilections, gender, feed source, substrate materials, gastrointestinal discomfort, and general health of the pig(s). It usually starts out as the pig being curious to investigate its surroundings and begins with harmless nibbling. The nibbling then turns into biting- if blood is drawn from the bite this can cause the pig to bite even more due to their natural appetite for blood.
Tail biting causes major financial and animal welfare issues within the commercial swine industries due to reduced weight gain, treatments, culling, and carcass condemnation. Studies have been done for farmers to identify the risk factors causing tail biting and to implement and experiment ways to reduce and prevent it. The studies ultimately yielded variable results due to the many factors of tail biting and the fact general recommendations are not appropriate for all farms.
Terminology
"Tail biting" mainly refers to bites which cause lesions on the victim., but there has not been a clear definition for "tail biting" so it is common for nibbling without injury to be considered a form of tail biting. Tail biting tends to happen when swine are housed in indoor facilities and in pens where multiple pigs are housed together. Crowding induces stress. Other factors in this circumstance that can cause stress in pigs are a lack of substrate material in the housing environment, a lack of ventilation, lack of quality feed (low salt or low iron diets) or access to the feed. Tail biting even happens out of pure boredom. Stressful situations, boredom and frustration motivate the actions of tail biting.
Types
The certain behaviors and conditions that tail biting happens under can be split up into three types: two-stage, sudden forceful, and obsessive.
Two-stage consists of two stages: pre-damage and damaging.
Pre-damage: This is light manipulation of the tail using the mouth of one pig on another. This tends to happen when both pigs are laying. With this type, the victim of the act tends to have little to no reaction to its tail being manipulated. Because pigs have an instinctive rooting behavior, the most likely cause of this type of tail biting is due to lack of a substrate/ground material for the pig to use its rooting behavior on, therefore it uses another pig's tail to fulfill that behavior. Ways to prevent this would be to remove the pig that's "biting" or remove the pigs that are being bitten, and/or provide some substrate or ground material to redirect the biting pig's rooting behavior.
Damaging: The oral manipulation causes the tail to bleed. This type tends to be more forceful where the pig actually bites the tail of the other pig. The victim pig will most likely respond with avoidance behavior, sometimes making sounds to indicate discomfort.
Sudden forceful: One pig actually grips onto the tail with its mouth and yanks. It usually happens when both pigs are standing up. The victim will usually display avoidance behavior and/or vocalize discomfort. This can cause wounds, sometimes even amputation. Some things to prevent this again would be to separate the biting pigs from the victim pigs and to provide substrate material or objects for the pigs to root.
Obsessive: The biting and yanking is repeated. Again, the response is avoidance behavior. The wounds are more severe and include partial or full amputation. To prevent, separate the bitten and victim pigs and treat the injured pigs.
Causes
Pigs go through teeth changes at ages 3–4 weeks and 7–8 months. Like humans and many other species, they go through teething phases which can prompt them to start tail biting. Pigs also have a natural tendency to chew and an attraction to blood, therefore if they start chewing on a tail and draw blood, it makes it harder for them to stop and can lead to infection. As pigs feel uncomfortable in their housing environment, they turn to biting and harming the tails of the pigs surrounding them. Factors that can trigger tail biting include environmental, husbandry, and diet factors like temperature, competition for food and water, vitamin E deficiency, and high fat diets.
Industry effects
Tail biting is considered one of the major animal welfare problems affecting the fattening of pigs in the swine industry. This is because of the costs to treat and costs due to slower fattening to slaughter weight. There are factors to be taken into account when evaluating how tail biting affects production since they have to do with growth, feed intake, leanness and other production traits. Some of those factors are genetics, breed, gender.
Prevention and management
The victim pigs of tail biting should be isolated from the others in order to prevent further damage. The tail can be dressed with a bandage and/or sprayed with an antiseptic. Broad spectrum antibiotics can be prescribed by a veterinarian to prevent and treat any infections. Meat withholding periods should be taken into account if antibiotics are prescribed.
To minimize tail biting, toys like chains, alkathene piping, and rubber boots can be provided to redirect pigs chewing tendencies. A substrate material for the flooring of the pen like feed or straw can provide additional enrichment in preventing tail biting as well. Tail docking is another way to prevent tail biting. This is done when piglets are 3–7 days old and should be done cleanly and efficiently by someone who is competent. Dietary supplements can be given to increase salt levels which has been shown to be effective. Salt levels should be monitored as to prevent excessive intake and salt poisoning. Other things that can be monitored and adjusted are potential stressors like stocking density, temperature and ventilation regulation. In regards to stocking density, there are minimum space requirements for pigs based on weight per The Welfare of Farmed Animals Regulations. Temperature and ventilation should be monitored and regulated as to prevent chilling, overheating, too much dust, gas, and ammonia buildup in turn decreasing stress induced tail biting.
References
Animal welfare
Intensive farming
Pigs
Biting | Tail biting in pigs | [
"Chemistry"
] | 1,396 | [
"Eutrophication",
"Intensive farming"
] |
49,072,410 | https://en.wikipedia.org/wiki/Luftwaffe%20and%20Kriegsmarine%20radar%20equipment%20of%20World%20War%20II | German Luftwaffe and Kriegsmarine Radar Equipment during World War II, relied on an increasingly diverse array of communications, IFF and RDF equipment for its function. Most of this equipment received the generic prefix FuG (), meaning "radio equipment". During the war, Germany renumbered their radars. From using the year of introduction as their number, they moved to a different numbering scheme.
Searchlight and fighter control
No German ground radar was accurate enough for flak fire direction. The method of operation during the day was for radar to direct the flak's optical fire control towards the target. Once this was acquired, the flak was controlled by the optical equipment to complete the engagement. During the night, the radar would be used to indicate the target to the searchlight crews. The rest of the engagement would be carried out optically. During the day, fighters would be directed with sufficient precision for them to come into visual contact with their targets, while during the night they would use their onboard aircraft interception (AI) radar to find the target after initial direction from the ground-based radars.
Early Units
Würzburg
The Würzburg was first operational in the summer of 1940, had a parabolic shaped antenna with a diameter of about 3metres and in some models could be folded in half for transport. The Würzburg was produced in the thousands with various estimated figures being between 3000 and 4000 with up to 1500 sets of Würzburg Riese. The antenna of the Würzburg weighed over 9.5 tons and its parabolic surface had a diameter equal to 7.5 metres and a focal length of one metres and 70 cm. Only one German company had the technical skill to build these radars, and that was
Zeppelin. The name of the unit was chosen at random by pointing at a map of Germany and Würzburg was chosen.
FuMG 62 / FuMG 39 Würzburg: 3D fire-control radar. Used to direct the flack optical directors and searchlights. Wavelength 50 cm approx. In response to jamming various models of Würzburg radar were developed to operate on various frequencies called "Islands".
Würzburg A First production version introduced in 1940. 50 cm operating wavelength. Operation range was approximately 30 km. Included an IFF system that worked with the FuG 25z airborne unit.
Würzburg B Integrated IR telescope to increase accuracy. Proved unsatisfactory and not placed into production.
Würzburg C Replaced the model A in production in 1941. Had lobe switching to improve accuracy. On this unit the integral IFF system was replaced by a system based on the FuG 25a airborne. To support this system which worked at approx 125-160 MHz two antenna were placed inside the main dish. A separate interrogation and receiving units were attached to show the IFF responses.
Würzburg D Replaced the model C in production in 1942. It now had a usable range of approximately 40 km. Conical scan was used for fine accuracy. The IFF antenna was now fitted in the center of the dish rather than on the sides. Better instruments were fitted and generally, it was the best of the small Würzburg.
FuMG 65 Würzburg Riese(Giant): The electronics of the D model Würzburg combined with a 7-meter dish to improve resolution and range. Range approx 70 km. Version E was a modified unit to fit on railroad flatcars to produce a mobile Flak radar system. Version G had the 2.4-meter antenna and electronics from a Freya installed. The antenna dipoles were inside the reflector. The reason for this was that the allies were flying very high recon flights which were above the maximum height of the Freya. The standard Würzburg Riese's 50 cm beam was too narrow to find them directly. By combining the two systems the Freya could set the Würzburg Riese onto the target.
Mannheim
FuMG 63 Mainz The Mainz, introduced in 1941, was a development from the Wurzburg with its 3-meter solid metal reflector mounted on top of the same type of control car as used by the ‘Kurmark’. Its range was 25–35 km with an accuracy of ±10–20 meters, azimuth 0.1 degrees, and elevation ±0.3-0.5 degrees. Only 51 units were produced before being superseded by the ‘Mannheim’.
FuMG 64 Mannheim The Mannheim was an advanced development from the ‘Mainz’. It also had a 3-meter reflector, which was now made from a lattice framework covered in a fine mesh. This was fixed to the front of a control cabin and the whole apparatus was rotated electrically. Its range was 25–35 km, with an accuracy of ±10–15 meters; azimuth and elevation accuracy of ±0.15 degrees. Though accurate enough to control Flak guns it was not deployed in large numbers. This was due to its cost (time and materials to manufacture was about three times that of a Würzburg D).
FuMG 75 Mannheim Riese Just as the Wurzburg's performance was greatly improved when fitted with a 7-meter reflector, so was the Mannheim's, and the result called a Mannheim Riese (Giant Mannheim). There was an optical device for the initial visual acquisition of the target. With its narrow beam it was relatively immune from ‘Window’. Its accuracy and automatic tracking enabled it to be used in anti-aircraft missile research to track and control the missiles in flight. Only a handful were manufactured.
FuMG 68 Ansbach There was a need for a mobile radar with the range and accuracy of the ‘Mannheim’. The result, in 1944, was the Ansbach. It had a collapsible reflector of diameter 4.5 meters, operating on a wavelength of 53.6 cm, and peak power of 8 kW, giving it a normal range 25–35 km (70 km in search mode) with an accuracy of 30–40 meters. Azimuth and elevation accuracy was around ±0.2°. The antenna and reflector were remote controlled from a Bayern control van up to 30 meters away. The control system was based on the remote control system of the Michael microwave communication system, this was based on the Ward-Leonard AC/DC control system. The Ansbach was to be installed in large Flak batteries with six or more guns, but only a few were produced by the end of the war, and these did not see operational service
Medium-range search
Freya & similar units
FuMG 450 Freya / FuMG 41G: This was a 2D Early warning radar. (2D means unable to indicate height). It was used for fighter direction and target indication for the Würzburg. Operating wavelength of approx 2.4 meters (125 MHz). In response to jamming various models were developed to operate on various frequencies called "Islands". Over 1000 units delivered in various models
FuMG 401 / FMG 42 FREYA - LZ (Models A - D). An Air portable version, the model differences were due to an operating frequency range being in 4 discrete bands between 91 and 200 MHz.
Freya-Rotschwarz and Freya-Grünschwarz: These two systems were Freya modified to operate on the same frequency as the British radio navigation system GEE to avoid jamming. However, as by the time they were ready the Germans were jamming GEE it is not clear whether any were ever deployed.
FuMG 451 A Freya Flamme: Freya which had been built to use the "Island D" band were modified to be able to trigger the British IFF equipment. Ranges of up to 450 km were obtained. Fell from use as British IFF procedures improved.
FuMG 401 Freya Fahrstuhl: A 3D version of the Fraya. (3D means could measure height). Measurements made by moving the antenna up and down on a rack. Only a very rough estimation of height available. originally intended for early warning most of the systems produced went to help "jammed" Würzburg
Freya EGON: EGON stood for Erstling Gemse Offensive Navigation system. Where Erstling was the codename of the Fug25a transceiver in the aircraft and Gemse was the codename for the receiver. The system operated on a principle similar to the British OBOE navigation system. An IFF signal was sent from a Freya, that had had its receiver antenna removed, to the aircraft. The Fug25a in the aircraft responded and the received signal was displayed as a range offset on the Freya display. Using a second transmitter and triangulation the position of the aircraft was resolved. Though the system was tested to guide night fighters it was found to be to limited by the number of aircraft that it could control at one time (the same limitation was found with Oboe). The "Y system" was used instead for night fighter control. The EGON system was used to control pathfinders for bombing raids over both England and Russia, however, by now the Luftwaffe bomber force was running out of planes, pilots and fuel so the results were minimal. Work was done using a third transmitter to improve system performance. Range with a normal Freya was up to 250 km, work was underway to use a Wasserman system instead of a Freya to increase range too 350 km. (the Freya signal was too weak to trigger the Fug25a at ranges beyond 250 km), but this was not completed.
Long-range search
For area air defense (vs point defense) Freya's range was found to be insufficient. This led to attempts to use Freya technology to achieve greater range. This resulted in the Wassermann and Mammut. Although the Mammut units achieved their aims they were large installations with large arrays built on bunkers. This resulted in long building times and vulnerability to air attacks. The Wassermann was a better solution in that being smaller they were harder to locate and quicker to build, 3–4 weeks. However, sources indicate that they never achieved the desired range of 400 km, the best was approx 300 km. This may be why there were so many variants deployed.
FuMG 401 Mammut: First deployed in 1942 this was a long range 2D search radar. It consisted of 8 Freya class antenna arranged in a 4 x 2 configuration. It measured 25 meters wide and ten meters high and was mounted on four pylons fixed in concrete. Some installations had a second array mounted back-to-back. Each array could be electronically swung through about 100 degrees, so the dual sided array could look behind itself to continue to track bombers as they flew into Germany. Frequency was the same as Freya (125 MHz). Range was up to 300 km with a transmit power of 200 kW. Installations being very large took up to four months to build.
FuMG 402 Wassermann: This system was deployed in 1942. It was basically six Freya antenna mounted on a rotation cylinder. Frequencies were similar to Freya (125 MHz) transmit power was 100 kW, resulting in a usable range of approx 200 km. Three main versions were produced with sub variants in each class.
Wassermann L: The original light version. Some sources indicate that it had structural problems.
Wassermann S: The heavy version. First deployed late 1942 Some sources indicate it had more than six arrays.
Wassermann M: The last family were the medium class units. Again, it is not clear exactly how many Freya arrays were attached to the mast. In 1944, this version received a modification that allowed it to electronically tilt its beams by 16 degrees which allowed it to perform height determination turning it into a 3D search radar.
Elefant & See Elefant: These bi-static radars were an attempt to combine jamming resistance with long range. They operated in two bands 23–28 MHz or 32–38 MHz. Range was approximately 400 km but under certain RF conditions much greater ranges were obtained. Antenna were usually mounted on Wassermann towers (all units differed in detail from each other). Three Elefants were in operation at the end of the war with one See Elefant. Sources are unclear what the difference between the two types were.
Panoramic search
The first type of early-warning radar set giving a panoramic display which come into operation is usually referred to as the Jagdschloss, although its official designation is Jagdschloss F, to distinguish it from later types, such as the Michael B and Z.
Jagdschloss F: The antenna was 24 m wide and 3 m high, consisting of sixteen pairs of double horizontal transmit and receive dipoles. Above this, an 8.5 metre wide antenna array of eight vertical dipoles was mounted for the IFF.The first 62 Jagdschloss were of the Voll Wismar type using wide band antenna covering the band 1.90-2.20 metres. Another 18, used the band 1.20–1.90 meters. Range was 100 km. An optional feature known as Landbriefträger (Postman) was a remote PPI display for use with Jagdschloss. This allowed the PPI display from the radar station to be sent simultaneously to command HQ by HF cable, or by a UHF radio link.
Jagdschloss Michael B: A ponderous aerial array of two rows of eighteen Würzburg mirrors measuring 56 metres long x 7 metres high was used in the Würzmann experimental early-warning radar, and formed the serial array for Jagdschloss Michael B with the array in a horizontal position. The wavelength employed, was that of a Voll Wismar 53.0-63.8 cm. Range approx 250 km. None may have entered service, though one source mentions one entering service.
Forsthaus F: This system was a development of the Jagdschloss Michael B using the so-called Euklid 25–29 cm. waveband employed by the Navy. Once more a very long aerial array 48 metres long and about 8 metres high was used, employing a cylindrical paraboloid. A wave guide antenna (Hohlraumstrahler) was placed along the focal line with a second and a third wave guide parallel to it above and below respectively. Range was expected to be over 200 km. Probably none completed.
Forsthaus KF: Development of the Forsthaus F. Reduced in size so that the system would fit in a railway carriage. Antenna 24 meters long. Range 120 km.
Dreh Freya: This set, which was also known as Freya Panorama, was first introduced in June 1944. It consisted of a Freya aerial of the Breitband type working in Bereich I (1.90-2.50), the frequency of which could be adjusted at will. The aerial was so built that it rotated through 360° and gave a remote panoramic presentation. About 20 units were in use in January 1945. The range claimed for it was only about 100 km.
Jagdhütte:This apparatus, which was produced by Siemens, gave a panoramic PPI display of the German IFF responses, using 24- or 36-metre rotating aerials. The wavelength employed was 2.40 metres and it was planned, with its aid, to trigger off the FuGe 25A. In this way, friendly fighters were to be controlled from the ground at ranges up to about 300 km. It was fully realised that if the FuGe 25A frequency was ever jammed the Jagdhütte would be useless, but it was not considered likely that the Allies would attempt to jam it. Small numbers may have been completed at the end of the war.
Jagdwagen: Jagdwagen was designed as a mobile panoramic radar to control fighters at close ranges immediately behind the front. It was a project of the firm of Lorenz. The aerials were considerably smaller than the Jagdhütte, the array being only 8 metres long. The aerial array was to be mounted on the Kumbach stand as used in the Egerland Flak set. The frequency band used was that of the ASV set Hohentwiel namely 53–59 cm. Range 40–60 km. Prototypes only.
Jagdhaus (FuMG 404): Jagdhaus was designed and built by Lorenz in 1944 as an early warning radar. It was the most powerful radar built by the Germans, with a peak pulse power of 300 kW, which Lorenz planned to increase to 750 kW. The whole assembly was the size of a house, which is possibly how it got its name (‘haus’ being the German for ‘house’). The rotating upper part of the construction housed the separate parabolic transmit and receive antennae and reflectors, with the IFF above them as usual. It weighed 48 tons and rotated at 10 rpm. It operated on wavelengths of 1.4 to 1.8 metres, and had a range of about 300 km. It could measure altitude, azimuth and range. The control room was located below the antennae, from which its PPI image was also transmitted to command HQ at Charlottenberg by Landbrieftrager, similar to the Jagdschloss system. It is believed that only one Jagdhaus was constructed, which fell into Soviet hands when it was captured by their troops in 1945, during which time it was damaged. The Soviets compelled the Germans to repair it and instruct them in its operation.
Aircraft intercept
Lichtenstein B/C - FuG 202: Low-UHF band frequency range, introduced in 1941 it was the initial AI radar. Deployed in large numbers with 32-dipole element Matratze (mattress) antenna arrays, it operated on the 61 cm wavelength. Its range was (in theory) 2–3 km but in practise was found to be dependent on factors such as height. Compromised to the Allies on May 9, 1943.
Lichtenstein C-1 - FuG 212: Introduced in 1943, this was an improved version of the FuG 202.
Lichtenstein SN2 - FuG 220: Low-mid VHF band frequency range, introduced in 1943 in response to Allied jamming, and used an eight-dipole Hirschgeweih (a stag's antlers) antenna array. Transmitter power of 2 kW on 3.3 meters. Range was increased to 6 km. Minimum range was 400 m, which was found to be a problem, hence aircraft carried it and FuG202. Later versions did away with the need for the Fug 202. Compromised to the Allies in July 1944.
Lichtenstein SN3 - FuG 228: A higher-powered version of the SN2. Range increased to 8 km. Only a small number accepted into service, perhaps only prototypes.
FuG 214 : This was an "add-on" unit to the SN2 which gave it an additional, rear-facing antenna installation. This was in response to Allied night fighters accompanying the bomber streams to hunt the German night fighters while they hunted the bombers. The idea was to prevent Allied fighters attacking the German fighters from behind.
Neptun 1 - FuG 216: A small number of experimental sets fitted to Fw 190 and Bf 109. Wavelength 1.3 to 1.8 meters.
Neptun 2 - FuG 217: A small number of sets fitted to Fw 190 and Bf 109. 1.6 to 1.8 meters wavelength. Some had a rear warning component.
Neptun 3 - Fug 218: A replacement for SN2, deployed late 1944 after SN2 was jammed. Wavelength 1.6 to 1.9 meters, most often using same, eight-dipole "stag's antlers" antenna array with shorter dipole elements. Range up to 5 km. Some were fitted to Me 262 to create night fighters that could catch Mosquito intruders.
Neptun 4 - FuG 219: Increased power version of the FuG218, experimental sets only.
Berlin A - FuG 224: The first centimetric (3 GHz) band radar. Based on a captured H2S radar unit, codenamed "Rotterdams". Unknown number built but under 100. Range 5K under ideal conditions, 10 cm wavelength.
Berlin N1 - FuG 240 N: Combination of the Berlin A and the SN2. Only small numbers delivered.
Berlin N2: Increased power Berlin N, Range reported to be 9K.
Berlin N3/N4: Experimental units.
Bremen - FuG 244: (also known as Berlin D) Berlin A with the frequency changed to 3 cm (10 GHz) rather than 9 cm. Experimental.
Bremen O - FuG 245: Another experiments 3 cm unit.
Air-to-surface search
Neptun: Early system - It failed its acceptance tests - the system was later reworked into an aircraft intercept set.
Hohentwiel (FuG 200); UHF-band radar, operated at wavelength between 52 and 57 cm. Range was between 10 km for a small vessel like a surfaced submarine to 70 km for a large ship. Under the best circumstances it could see the coast at approx 150 km. It had separate antennae for transmit and receive. The transmit antenna was centrally mounted, pointing forward, while the two receive antennae were mounted either side, pointing outwards by 30 degrees, giving it a search beam width of about 120 degrees. Each antenna array consisted of sixteen horizontally polarised dipoles, mounted in four groups of four in a vertical stack.
A variant of the Hohentwiel the Tiefentwiel (FuMG407); was tried as an Air Surveillance radar on the coast to try and detect low flying aircraft.
Naval surface search - land based - Seetakt
FuMO 1 - Calis A: Its 6.2 x 2.5m antenna consisted of 2 rows of eight full wave vertical dipoles. Its wavelength was 82 cm and its range depended on the height it was installed above sea level, but typically was about 15–20 km. Given the frequency low angle reflections from the surface, also known a clutter would have been an issue.
FuMO 2 - Calis B: Improved version of the FuMO 1 - similar clutter problems but improved transmitter and accuracy.
FuMO 3 - Zerstorersaule: A version of the destroyer radar modified for land use.
FuMO 4 - Dunkirchen : Improved version of the FuMo 2 - similar otherwise
FuMO 5 - Boulogne: Yet another improved version of the FuMO 2 - increased transmitter power again with an improved aerial - usable range now 40 – 50 km.
FuMO 11 - Renner: 3M antenna from a Wurzburg combined with a 9 cm "Berlin" unit and mounted on a Seetakt base optimized for sea search rather than air search. Sources differ on usable range.
FuMO 12 & 13: Improved Renner units to attempt to compensate for poor reliability with the original unit.
FuMO 15 - Sheer: Combination of a Berlin 9 cm and an Antenna from a Giant Wurzburg - seems to have been optimized for surface search in the same was as the Renner series was.
FuMO 51 - Mammut G: Version of the Luftwaffe FuMO401 but with Seetakt antenna and waveforms to optimise it for surface search rather than air search.
FuMO 214 - Giant Wurzburg: Naval designation for the airforce unit.
FuMO 215 See Reise: Improved FuMO 214
Naval air search - land based - Flugmeldung
FuMO 52: Naval designation for the FuMG 401 Mammut C.
FuMO 64 : A version of the Hohentwiel L ASV radar modifier for coastal air search - different from the unsuccessful xxx
FuMO 221: Naval designation for the FuMG 64 Mannheim.
FuMO 301 - 303: Versions of the FuMG 39-41 Freya
FuMO 311 - 318: Versions of the Freya working on other frequencies (Around 2.2 Meters) from the normal Freya. Sometimes known as the Freiburg
FuMO 321 - 328: Based on the fuMO311 family of units but working at 1.5 meters.
FuMO 331: Naval designation for the FuMG 402 Wassermann M
FuMO 371: Naval designation for the FuMG 403 Jagdschloss
Naval flak direction - land based - Flakziel
FuMO 201: Flakleit - Using Seetakt 80 cm technology a 3D radar mounted on an underground armoured turret (originally an optical rangefinder) small numbers produced. Multiple antenna. Manufactured by GEMA.
FuMO 211 - 213: Naval designation for the FuMG 62 family or radars - the Wurzburg A, C & D.
FuMO 215: See Reise.
FuMO 221: Mannheim.
Naval coastal battery fire control - Seeart
FuMO 111: Barbara, 9 cm fire control radar based on modifying a FuMO 15 Giant Wurzburg to operate at 9 cm. Only experimental radars produced.
FuMO 214: A Wurzburg Reise reconfigured for use as a naval radar with a range of approximately 50 – 70 km against surface targets.
FuMO 215: Improved range version of the FuMO214.
Centimeter radars
Although the Germans were carrying out research at centimeter wavelengths at the start of the war, the work was abandoned as it was decided that the war would be over before the research and development could be completed. In February 1943 an RAF Stirling bomber was shot down over Rotterdam and a damaged H2S system was recovered. The Germans started a crash development program to use the information deduced from the captured system. Although a range of prototypes were produced, very few reached front line troops. Due to the device being recovered near Rotterdam, the Germans used that name in several code names for the Centimeter (9 cm) systems, such as "Rotterdam Device".
Rotterdam: To get the quickest start with development, German industry copied, as far as possible, the H2S system. Approximately 20 systems were manufactured for R&D work. They led to the Roderich jammer and the Berlin & Korfu receivers.
Jagdschloss Z: The 9 cm version of the Jagdschloss F panoramic radar system. Prototypes only.
Forsthaus Z: The 9 cm version of the Forsthaus panoramic search radar. Prototypes only.
FuMG 77: Rotterheim. A combination of the 9 cm receiver/transmitter of the Berlin system with the antenna and other systems from a Mannheim. Its range was about 30 km and it was found to be unaffected by Allied jamming. Its name changed to Marbach V later in the war.
FuMG 76: Marbach. A combination of the Berlin transmitter/receiver with the Ansback 4.5 meter reflector and systems. Controlled by the "Michael" remote control system. Sources suggest that three systems were completed.
FuMG 74: Kulmbach. A 9 cm panoramic search radar, 6 meter antenna and remote controlled like the FuMG76. When combined with that radar it was known as the Egerland system. Only two were completed, with a range of approx 50 km.
Passive search
FuG 221 Freya-Halbe: This was a Freya modified to locate British airborne jammers. Development completed but due to lack of parts never deployed.
FuG 221 Rosendahl: This was a Freya modified to locate British bombers by tracking their Monica warning radar emissions. By the time development was completed the British had ceased using Monica, so never deployed
FuG 223: A family of passive airborne receivers tuned to various radar bands such as Freya and Würzburg. Designed to allow night fighters to home onto bombers fitted with jammers against those radars. The Fug223 was a version build from surplus FuG 227 components that detected reflected energy from an aircraft being illuminated by a ground radar. In this way it was an example of an early semi-active radar homing system. In order to work it seems that the radar beam had to illuminate the target and the night fighter so that the two receivers could be synchronized. Used by one test and development squadron at the end of the war.
FuG 227 Flensburg: Built using some components from the FuG 220 range of AI equipment. This was a passive device which allowed night fighters to home onto bombers which had their rear warning 'Monica' active. Monica was a short range VHF radar (200 MHz band) which was fitted to the tail of British heavy bombers facing down and back to give the rear turret gunner a warning display. Using this equipment the night fighters could achieve intercept with apparent ease. Extremely effective until the British captured a Junkers Ju 88G-1 night fighter with FuG 227 installed in July 1944, and realised its mode of operation. there after Monica was removed from bombers and FuG 227 ceased to have any value.
Klein Heidelberg was the code-name give to a passive radar system devised in 1941. The system was a bi-static radar system. What was unusual was that the transmitters were British rather than German! The system worked by using the reflections from the Chain Home (British coastal radar system) rather than transmitters associated with the receivers. Klein Heidelberg worked by sensing Chain Home (CH) transmission pulses directly with a small auxiliary antenna, close to the main antenna, whose receiver was tuned to a particular CH station whose exact location, bearing and range was known. The CH signal was then used to synchronise the KH with the CH transmission pulses. The CH pulse started a circular trace on a cathode ray tube (CRT) divided into forty sections. The main antenna received the reflection of these pulses from the target and displayed them on the CRT. Range was between 300 and 600 km. The display was 2D. Resolution was not very good but it allowed the Germans to see bomber formations forming up over England and the general path of the bomber streams. Its big advantage was it was not possible for the British to jam without jamming their own radars. The system entered service in late 1943 and by late 1944 six system were commissioned on the Dutch coast.
FuG 350 Naxos & FuG 351 Korfu: This was a family or radar detectors that operated in the 8 to 12 cm band. They were primarily designed to locate Allied H2S radar transmissions. A range of antenna were used some stationary and some rotating. There were intended to be air, land and maritime versions. However, Naxos had a resolution problem that limited its ability to distinguish individual aircraft. This allowed the night fighter to locate the bomber stream but not usually individual bombers. This was not usually an issue with the maritime based system (primarily U-boats) as there was usually only one aircraft detected at a time. To reduce this issue an improved version the Korfu was developed. It was intended to field Korfu as a replacement for Naxos in all three versions but due to a shortage of components only the land-based version was fielded where is resolution could be used to the best effect.
FuG 350 Naxos Z: The original system, detected H2S radar system on bombers. Unable to distinguish individual bombers nor the 10 GHz H2X Allied bombing radar, but could reliably guide the fighter into the bomber stream.
FuG 350 Naxos ZR: Additional aerials added a tail warning system which allowed British night-fighters to be detected.
FuG 350 Naxos ZX: 3 cm version for detecting allied H2X radars. Not known to have ever been fielded.
FuG 350 Naxos RX: 3 cm version of the Naxos ZR. Not known to have ever been fielded.
FuG 350 Naxos ZD: Combined Z and ZX, allowing 9 cm and 3 cm detection in the same system.
FuG 351 Korfu Z: Entered production late 1944, due to shortage of components only ground-based versions deployed though an airborne version completed development. better range and discrimination than Naxos.
FuG 280 Kiel Z: IR-based passive receiver. 10-degree field of view - display via CRT. Problems with discrimination between fires aircraft and other IR sources.
Falter: Based on the Fug 280 K but detected British IR recognition systems. Development not completed.
References
Notes
Bibliography
Muller, Werner. Ground Radar Systems of the Luftwaffe. Schiffer Publishing Limited, 1998.
Prichard, David. "The Radar War: Germany's Pioneering Achievement 1904-45". Harpercollins August 1989.
External links
Luftwaffe radio equipment
World War II German electronics
Radio spectrum
Military terminology
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Communication circuits
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World War II German radars | Luftwaffe and Kriegsmarine radar equipment of World War II | [
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54,259,556 | https://en.wikipedia.org/wiki/Mongolian%20units | Mongolian units are the traditional units of measurement of the Mongolian people.
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54,260,744 | https://en.wikipedia.org/wiki/Pentachlorobenzenethiol | Pentachlorobenzenethiol is a chemical compound from the group of thiols and organochlorine compounds. The chemical formula is .
Synthesis
Pentachlorobenzenethiol can be obtained from hexachlorobenzene.
Properties
Pentachlorobenzenethiol is a combustible gray solid with an unpleasant odor, practically insoluble in water. It has a monoclinic crystal structure. The compound is not well-biodegradable and presumably bioaccumulable and toxic for aquatic organisms.
Pentachlorobenzenethiol is itself a metabolite of hexachlorobenzene and is found in the urine and the excretions of animals receiving hexachlorobenzene. Pentachlorobenzenethiol has a high potential for long-range transport via air as it is very slowly degraded in atmosphere.
Applications
Pentachlorobenzenethiol is used in the rubber industry. The compound is added to rubber (both natural and synthetic) to facilitate processing (mastication).
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Chlorobenzene
Dichlorobenzene
Trichlorobenzene
Pentachlorobenzene
Hexachlorobenzene
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54,262,313 | https://en.wikipedia.org/wiki/Pauls%20Stradi%C5%86%C5%A1%20Jr | Pauls Stradiņš Jr. (born 1963) is a physicist at the National Renewable Energy Laboratory in Golden, Colorado, and a foreign member of the Latvian Academy of Sciences.
Currently he is the principal scientist and a project leader of the silicon photovoltaics group at NREL. He leads a team that recently theorized that defects in photovoltaic cells could actually improve the performance of those cells.
He is the grandson of Pauls Stradiņš (17 January 1896 – 14 August 1958), a Latvian professor and physician.
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21st-century American inventors | Pauls Stradiņš Jr | [
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"Silicon photonics"
] |
54,262,404 | https://en.wikipedia.org/wiki/Printer%20tracking%20dots | Printer tracking dots, also known as printer steganography, DocuColor tracking dots, yellow dots, secret dots, or a machine identification code (MIC), is a digital watermark which many color laser printers and photocopiers produce on every printed page that identifies the specific device that was used to print the document. Developed by Xerox and Canon in the mid-1980s, the existence of these tracking codes became public only in 2004.
History
In the mid-1980s, Xerox pioneered an encoding mechanism for a unique number represented by tiny dots spread over the entire print area, and first deployed this scheme in its DocuColor line of printers. Xerox developed this surreptitious tracking code "to assuage fears that their color copiers could be used to counterfeit bills" and received U.S. Patent No. 5515451 describing the use of the yellow dots to identify the source of a copied or printed document. The scheme was then widely deployed in other printers, including those made by other manufacturers.
The public first became aware of the tracking scheme in October 2004, when Dutch authorities used it to track counterfeiters who had used a Canon color laser printer. In November 2004, PC World reported the machine identification code had been used for decades in some printers, allowing law enforcement to identify and track counterfeiters. The Central Bank Counterfeit Deterrence Group (CBCDG) has denied that it developed the feature.
In 2005, the civil liberties activist group Electronic Frontier Foundation (EFF) encouraged the public to send in sample printouts and subsequently decoded the pattern. The pattern has been demonstrated on a wide range of printers from different manufacturers and models. The EFF stated in 2015 that the documents that they previously received through a Freedom of Information Act request suggested that all major manufacturers of color laser printers entered a secret agreement with governments to ensure that the output of those printers is forensically traceable.
In 2007, the European Parliament was asked about the question of invasion of privacy.
Technical aspects
The pattern consists of a dot-matrix spread of yellow dots, which can barely be seen with the naked eye. The dots have a diameter of and a spacing of about . Their arrangement encodes the serial number of the device, date and time of the printing, and is repeated several times across the printing area in case of errors. For example, if the code consists of 8 × 16 dots in a square or hexagonal pattern, it spreads over a surface of about and appears on a sheet of size A4 paper about 150 times. Thus, it can be analyzed even if only fragments or excerpts are available. Some printers arrange yellow dots in seemingly random point clouds.
According to the Chaos Computer Club in 2005, color printers leave the code in a matrix of 32 × 16 dots and thus can store 64 bytes of data (64×8).
, Xerox was one of the few manufacturers to draw attention to the marked pages, stating in a product description, "The digital color printing system is equipped with an anti-counterfeit identification and banknote recognition system according to the requirements of numerous governments. Each copy shall be marked with a label which, if necessary, allows identification of the printing system with which it was created. This code is not visible under normal conditions."
In 2018, scientists at the TU Dresden analyzed the patterns of 106 printer models from 18 manufacturers and found four different encoding schemes.
Visibility
The dots can be made visible by printing or copying a page and subsequently scanning a small section with a high-resolution scanner. The yellow color channel can then be enhanced with an image processing program to make the dots of the identification code clearly visible. Under good lighting conditions, a magnifying glass may be enough to see the pattern. Under UV-light, the yellow dots are clearly recognizable.
Using this steganographic process, high-quality copies of an original (e.g. a banknote) under blue light can be made identifiable. Using this process, even shredded prints can be identified: the 2011 "Shredder Challenge" initiated by the DARPA was solved by a team called "All Your Shreds Are Belong To U.S." consisting of Otávio Good and two colleagues.
Practical application
Both journalists and security experts have suggested that The Intercept handling of the leaks by whistleblower Reality Winner, which included publishing secret NSA documents unredacted and including the printer tracking dots, was used to identify Winner as the leaker, leading to her arrest in 2017 and conviction.
Protection of privacy and circumvention
Copies or printouts of documents with confidential personal information, for example health care information, account statements, tax declaration or balance sheets, can be traced to the owner of the printer and the inception date of the documents can be revealed. This traceability is unknown to many users and inaccessible, as manufacturers do not publicize the code that produces these patterns. It is unclear which data may be unintentionally passed on with a copy or printout. In particular, there are no mentions of the technique in the support materials of most affected printers. In 2005, the Electronic Frontier Foundation (EFF) sought a decoding method and made available a Python script for analysis.
In 2018, scientists from TU Dresden developed and published a tool to extract and analyze the steganographic codes of a given color printer and subsequently to anonymize prints from that printer. The anonymization works by printing additional yellow dots on top of the printer's tracking dots. The scientists made the software available to support whistleblowers in their efforts to publicize grievances.
Comparable processes
Other methods of identification are not as easily recognizable as yellow dots. For example, a modulation of laser intensity and a variation of shades of grey in texts are feasible. , it was unknown whether manufacturers were also using these techniques.
See also
EURion constellation, a dot matrix spread over a bank note, which stops some printers and color copiers from processing
References
External links
Laudatio der deutschen BigBrotherAwards 2004
Information by the Chaos Computer Club
Information by the Electronic Frontier Foundation
EFF List of Printers Which Do or Do Not Display Tracking Dots (last updated 2017)
Identity documents
Printing software
Privacy software
Steganography
Watermarking
Computer-related introductions in the 1980s
Money forgery
Hardware restrictions | Printer tracking dots | [
"Engineering"
] | 1,290 | [
"Cybersecurity engineering",
"Computer forensics"
] |
54,262,912 | https://en.wikipedia.org/wiki/Hypersequent | In mathematical logic, the hypersequent framework is an extension of the proof-theoretical framework of sequent calculi used in structural proof theory to provide analytic calculi for logics that are not captured in the sequent framework. A hypersequent is usually taken to be a finite multiset of ordinary sequents, written
The sequents making up a hypersequent are called components. The added expressivity of the hypersequent framework is provided by rules manipulating different components, such as the communication rule for the intermediate logic LC (Gödel–Dummett logic)
or the modal splitting rule for the modal logic S5:
Hypersequent calculi have been used to treat modal logics, intermediate logics, and substructural logics. Hypersequents usually have a formula interpretation, i.e., are interpreted by a formula in the object language, nearly always as some kind of disjunction. The precise formula interpretation depends on the considered logic.
Formal definitions and propositional rules
Formally, a hypersequent is usually taken to be a finite multiset of ordinary sequents, written
The sequents making up a hypersequent consist of pairs of multisets of formulae, and are called the components of the hypersequent. Variants defining hypersequents and sequents in terms of sets or lists instead of multisets are also considered, and depending on the considered logic the sequents can be classical or intuitionistic. The rules for the propositional connectives usually are adaptions of the corresponding standard sequent rules with an additional side hypersequent, also called hypersequent context. E.g., a common set of rules for the functionally complete set of connectives for classical propositional logic is given by the following four rules:
Due to the additional structure in the hypersequent setting, the structural rules are considered in their internal and external variants. The internal weakening and internal contraction rules are the adaptions of the corresponding sequent rules with an added hypersequent context:
The external weakening and external contraction rules are the corresponding rules on the level of hypersequent components instead of formulae:
Soundness of these rules is closely connected to the formula interpretation of the hypersequent structure, nearly always as some form of disjunction. The precise formula interpretation depends on the considered logic, see below for some examples.
Main examples
Modal logics
Hypersequents have been used to obtain analytic calculi for modal logics, for which analytic sequent calculi proved elusive. In the context of modal logics the standard formula interpretation of a hypersequent
is the formula
Here if is the multiset we write for the result of prefixing every formula in with , i.e., the multiset . Note that the single components are interpreted using the standard formula interpretation for sequents, and the hypersequent bar is interpreted as a disjunction of boxes. The prime example of a modal logic for which hypersequents provide an analytic calculus is the logic S5. In a standard hypersequent calculus for this logic the formula interpretation is as above, and the propositional and structural rules are the ones from the previous section. Additionally, the calculus contains the modal rules
Admissibility of a suitably formulated version of the cut rule can be shown by a syntactic argument on the structure of derivations or by showing completeness of the calculus without the cut rule directly using the semantics of S5. In line with the importance of modal logic S5, a number of alternative calculi have been formulated. Hypersequent calculi have also been proposed for many other modal logics.
Intermediate logics
Hypersequent calculi based on intuitionistic or single-succedent sequents have been used successfully to capture a large class of intermediate logics, i.e., extensions of intuitionistic propositional logic. Since the hypersequents in this setting are based on single-succedent sequents, they have the following form:
The standard formula interpretation for such an hypersequent is
Most hypersequent calculi for intermediate logics include the single-succedent versions of the propositional rules given above and a selection of the structural rules. The characteristics of a particular intermediate logic are mostly captured using a number of additional structural rules. E.g., the standard calculus for intermediate logic LC, sometimes also called Gödel–Dummett logic, contains additionally the so-called communication rule:
Hypersequent calculi for many other intermediate logics have been introduced, and there are very general results about cut elimination in such calculi.
Substructural logics
As for intermediate logics, hypersequents have been used to obtain analytic calculi for many substructural logics and fuzzy logics.
History
The hypersequent structure seem to have appeared first in under the name of cortege, to obtain a calculus for the modal logic S5. It seems to have been developed independently in, also for treating modal logics, and in the influential, where calculi for modal, intermediate and substructural logics are considered, and the term hypersequent is introduced.
References
Proof theory | Hypersequent | [
"Mathematics"
] | 1,101 | [
"Mathematical logic",
"Proof theory"
] |
54,263,883 | https://en.wikipedia.org/wiki/NGC%207029 | NGC 7029 is an elliptical galaxy located about 120 million light-years away from Earth in the constellation Indus. NGC 7029 has an estimated diameter of 129,000 light-years. It was discovered by astronomer John Herschel on October 10, 1834. It is in a pair of galaxies with NGC 7022.
One supernova has been observed in NGC 7029: SN 2023qov (type Ia, mag. 17.5).
Group Membership
NGC 7029 is part of the Indus Triplet of galaxies which contains the galaxies NGC 7041 and NGC 7049.
See also
List of NGC objects (7001–7840)
NGC 7002
References
External links
Elliptical galaxies
Indus (constellation)
7029
66318
Astronomical objects discovered in 1834 | NGC 7029 | [
"Astronomy"
] | 154 | [
"Indus (constellation)",
"Constellations"
] |
54,264,237 | https://en.wikipedia.org/wiki/Estriol%203-glucuronide | Estriol 3-glucuronide, or oestriol 3-glucuronide, also known as estriol 3-β-D-glucosiduronic acid, is a natural, steroidal estrogen and a glucuronic acid (β-D-glucopyranuronic acid) conjugate of estriol. It is found in the urine of women as a reversibly formed metabolite of estriol. The positional isomer of estriol 3-glucuronide, estriol 16α-glucuronide, also occurs as an endogenous metabolite of estriol, but to a much greater extent in comparison.
See also
Estrogen conjugate
Estradiol glucuronide
Estrone glucuronide
Estradiol sulfate
Estrone sulfate
Lipoidal estradiol
Catechol estrogen
References
External links
Metabocard for Estradiol 3-Glucuronide – Human Metabolome Database
Estriol esters
Estrogens
Glucuronide esters
Hormones of the hypothalamus-pituitary-gonad axis
Hormones of the pregnant female
Human metabolites
Sex hormones | Estriol 3-glucuronide | [
"Biology"
] | 265 | [
"Behavior",
"Sexuality",
"Sex hormones"
] |
54,265,281 | https://en.wikipedia.org/wiki/International%20Journal%20on%20Semantic%20Web%20and%20Information%20Systems | The International Journal on Semantic Web and Information Systems (IJSWIS) is a quarterly peer-reviewed academic journal covering the semantic web and information systems. It was established in 2005 and is published by IGI Global. The editor-in-chief is Brij B. Gupta, Who is a professor at Asia University, Taiwan, and Director of the International Center for AI and Cyber Security Research and Innovations. Brij B. Gupta is also serving as Member-in-Large, Board of Governors, IEEE Consumer Technology Society (2022–2024) and also included in the list of 2022 Highly Cited Researchers in Computer Science by Clarivate.
Abstracting and indexing
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2023 impact factor of 4.1
References
External links
Academic journals established in 2005
English-language journals
Quarterly journals
Semantic Web and Information Systems, International Journal on
Computer science journals
Semantic Web
Information systems journals | International Journal on Semantic Web and Information Systems | [
"Technology"
] | 198 | [
"Information systems journals",
"Information systems"
] |
54,265,310 | https://en.wikipedia.org/wiki/Estrone%20sulfamate | Estrone sulfamate (EMATE; developmental code name J994), or estrone-3-O-sulfamate, is a steroid sulfatase (STS) inhibitor which has not yet been marketed. It is the C3 sulfamate ester of the estrogen estrone. Unlike other estrogen esters however, EMATE is not an effective prodrug of estrogens. A closely related compound is estradiol sulfamate (E2MATE), which is extensively metabolized into EMATE and has similar properties to it.
EMATE shows high bioavailability and undergoes little or no first-pass metabolism with oral administration. The sulfamate moiety of EMATE results in carbonic anhydrase binding which, in turn, results in EMATE being taken up into and stored in erythrocytes in the blood. Since this occurs in the hepatic portal vein, it prevents EMATE from entering the liver during the first pass with the oral route. The inhibition of STS by EMATE prevents its bioactivation into estrone and estradiol, which in turn accounts for the lack of estrogenicity of EMATE. A short initial peak of estradiol and estrone levels was observed with E2MATE at the start of treatment in humans, followed by very high and long-lasting concentrations of EMATE and estrone sulfate in erythrocytes, observations that are in accordance with STS inhibition.
EMATE is an extremely potent and irreversible inhibitor of STS. It was found to have an of 65 pM for STS inhibition in MCF-7 cells, with an almost complete inhibition of the hydrolysis of physiological concentrations of the steroid sulfates estrone sulfate and dehydroepiandrosterone sulfate in MCF-7 cells observed at a concentration of 1 μM. At a dosage of 1 mg/kg orally or subcutaneously in rats, it effectively abolished estrone and DHEA-S sulfatase activities in all tissues assessed. It also showed a prolonged duration of action, with only a small recovery (<10%) of hepatic STS activity occurring 7 days after a single 10 mg/kg dose in rats.
Due to its ability to prevent the conversion of hormonally inactive steroid sulfates into their hormonally active forms (e.g., estrone sulfate into estrone), STS inhibitors like EMATE have potential applications in the treatment of estrogen-dependent conditions like estrogen receptor-positive breast cancer and endometriosis. However, estrogenicity was paradoxically observed with EMATE in rodents, and this resulted in clinical development of the compound not being pursued. However, E2MATE was investigated as an estradiol prodrug with improved oral pharmacokinetics and little or no first-pass hepatic impact in humans, but was found to completely lack estrogenic effects. Following this, E2MATE was repurposed as an STS inhibitor, and is now under development for the treatment of endometriosis.
See also
List of estrogen esters § Estrone esters
Steroid sulfatase § Inhibitors
References
Abandoned drugs
Estrone esters
Ketones
Steroid sulfatase inhibitors
Sulfamate esters | Estrone sulfamate | [
"Chemistry"
] | 681 | [
"Ketones",
"Functional groups",
"Drug safety",
"Abandoned drugs"
] |
54,266,624 | https://en.wikipedia.org/wiki/NGC%207025 | NGC 7025 is a spiral galaxy located about 210 million light-years away from Earth in the constellation Delphinus. NGC 7025 is also classified as a LINER galaxy. The galaxy has an estimated diameter of 161,830 light-years. It was discovered by astronomer Albert Marth on September 17, 1863.
See also
List of NGC objects (7001–7840)
NGC 7013
NGC 7001
References
External links
Spiral galaxies
LINER galaxies
Delphinus
7025
11681
66151
Astronomical objects discovered in 1863 | NGC 7025 | [
"Astronomy"
] | 108 | [
"Delphinus",
"Constellations"
] |
54,266,761 | https://en.wikipedia.org/wiki/Hibarimicinone | Hibarimicinone is an organic atropisomeric small molecule, derived from hibarimicins, which are isolated from the microbial culture strain of Microbispora rosea from the Hibari region of Japan. Analysis of the bacteria identified a new class of molecule containing a dimeric-tetracyclic polyketide backbone, which are now known as the hibarimicins. Hibarimicinone and its derivatives were initially extracted for their potential inhibitory properties of various protein kinases, such as calmodulin-dependent protein kinase III (CAMKIII), protein kinase A (PKA), protein kinase C (PKC), and protein tyrosine kinase (PTK).
The atropisomerism that the hibarimicin family possess arises from the hindered rotation about the biaryl axis connecting to the two monomers, with steric hindrance imposed by the four ortho substituents. The absolute configuration around the axis was elucidated by Romaine et al., utilizing a C2-symmetric shunt metabolite HMP-Y6, a glycosylated structural analogue of hibarimicinone, in tandem with biomimetic homocoupling.
Recent work by multiple groups have shown the total synthesis of hibarimicinone and its derivatives.
Biosynthesis
The biosynthesis of hibarimicinone was initially hypothesized to be produced from a polyketide synthase. Through 13C-labelling and blocked mutants of the TP-A0121 strain, Oki et al. demonstrated that hibarimicinone is produced by an oxidative coupling of two tetracyclic polyketides, which undergo an oxidative cyclization to generate the ether ring.
The hibarimicinone monomer is formed initially by a Type II polyketide synthase. The 22 carbon chain is initiated by butyryl-CoA and its decarboxylative addition to a malonyl-CoA derived two carbon ketide unit. The KS/CLF binds to the starting butyryl-CoA, freeing the ACP domain to bind to another malonate group from malonyl-CoA. Thioester exchange occurs between the KS/CLF and the ACP; the cycle then repeats nine more times to produce the full carbon chain (1). Multiple aldol additions occur to form four six-membered cyclization and aromization (2). The CLF/KS subunit is cleaved off by a thioesterase and modified by numerous steps (four oxidations, two NADPH dependent reductions, two methylations and decarboxylation) to form the final monomeric unit (3). Two monomer units undergo oxidative coupling to form the atropisomeric axis (4). Oxidative cyclization occurs on one end of the molecule to form the ether ring (5). Finally, the hydroquinone on the same side of the previously mentioned ether oxidizes to form the quinone species, giving hibarimicinone.
References
Heterocyclic compounds with 5 rings
Hydroxyarenes
Dimers (chemistry)
Triketones
3-Hydroxypropenals within hydroxyquinones
1,4-Naphthoquinones
Tetracyclic compounds
Methoxy compounds | Hibarimicinone | [
"Chemistry",
"Materials_science"
] | 713 | [
"Dimers (chemistry)",
"Polymer chemistry"
] |
54,266,997 | https://en.wikipedia.org/wiki/Passerelle%20%28theatre%29 | The word passerelle is a French word that means "footbridge" or "gangway." In the theatre, it refers to a small catwalk that extends from one side of the stage to the other, passing in front of the orchestra pit. Besides increasing the total stage area, this stage design allows performers to be closer to the audience.
Notable examples
One of the most prominent uses of a passerelle has been in the Broadway productions of the musical Hello, Dolly!. Notably, the show's memorable title song is staged – in part – on the passerelle.
References
Parts of a theatre
Stage terminology | Passerelle (theatre) | [
"Technology"
] | 128 | [
"Parts of a theatre",
"Components"
] |
54,268,322 | https://en.wikipedia.org/wiki/Cloud%20tree | A cloud tree is a tree shaped using topiary techniques. The leaves are pruned into a ball or cloud shape, leaving the stems thin and exposed. The shape of the tree as a whole resembles a set of clouds.
Cloud trees differ from bonsai trees because they are not miniature. Typically, cloud trees are planted in plain soil, rather than in pots.
Similarly to bonsai, the practice of shaping cloud trees comes from Japan, deriving from a Japanese style of gardening known as Niwaki.
Gallery
References
External links
http://www.silktree.co.uk/cloudtree.html
https://web.archive.org/web/20180312204223/http://warners.com.au/our-plants/plant/cloud-tree
Site of Royal Horticulture Society (RHS)
Japanese style of gardening
Landscape architecture
Trees | Cloud tree | [
"Engineering"
] | 184 | [
"Landscape architecture",
"Architecture"
] |
54,268,380 | https://en.wikipedia.org/wiki/Methyl%202-bromoacetate | Methyl 2-bromoacetate (methyl bromoactate) is a chemical compound with the molecular formula C3H5BrO2.
Properties
Methyl 2-bromoacetate is colorless or straw-colored liquid. The smell is sharp and penetrating. It is soluble in water and also has a higher density than water. It is incompatible with acids, bases, oxidizing agents, and reducing agents.
Application
Methyl bromoacetate is an alkylating agent. It has been used to alkylate phenol and amino groups. Moreover, it can be used to make vitamins and pharmaceutical drugs. It is commonly used as a reagent in chemical modification of histidine. In addition, methyl bromoacetate also use in synthesize of coumarins and cis-cyclopropane. It reacts with conjugated base and produce alkylated carbene complexes.
Safety
Methyl bromoacetate can be toxic by ingestion and inhalation. It can also irritate the skin and eyes.
See also
Ethyl bromoacetate
References
Extra reading
Organobromides
Methyl esters
Alkylating agents
Lachrymatory agents | Methyl 2-bromoacetate | [
"Chemistry"
] | 246 | [
"Alkylating agents",
"Lachrymatory agents",
"Chemical weapons",
"Reagents for organic chemistry"
] |
54,269,557 | https://en.wikipedia.org/wiki/Solar%20energy%20conversion | Solar energy conversion describes technologies devoted to the transformation of solar energy to other (useful) forms of energy, including electricity, fuel, and heat. It covers light-harvesting technologies including traditional semiconductor photovoltaic devices (PVs), emerging photovoltaics, solar fuel generation via electrolysis, artificial photosynthesis, and related forms of photocatalysis directed at the generation of energy rich molecules.
Fundamental electro-optical aspects in several emerging solar energy conversion technologies for generation of both electricity (photovoltaics) and solar fuels constitute an active area of current research.
History
Solar cells started in 1876 with William Grylls Adams along with an undergraduate student of his. A French scientist, by the name of Edmond Becquerel, first discovered the photovoltaic effect in the summer of 1839. He theorized that certain elements on the periodic table, such as silicon, reacted to the exposure of sunlight in very unusual ways. Solar power is created when solar radiation is converted to heat or electricity. English electrical engineer Willoughby Smith, between 1873 and 1876, discovered that when selenium is exposed to light, it produced a high amount of electricity. The use of selenium was highly inefficient, but it proved Becquerel's theory that light could be converted into electricity through the use of various semi-metals on the periodic table, that were later labelled as photo-conductive material. By 1953, Calvin Fuller, Gerald Pearson, and Daryl Chapin discovered the use of silicon to produce solar cells was extremely efficient and produced a net charge that far exceeded that of selenium. Today solar power has many uses, from heating, electrical production, thermal processes, water treatment and storage of power that is highly prevalent in the world of renewable energy.
Background
By the 1960s solar power was the standard for powering space-bound satellites. In the early 1970s, solar cell technology became cheaper and more available ($20/watt). Between 1970 and 1990, solar power became more commercially operated. Railroad crossings, oil rigs, space stations, microwave towers, aircraft, etc. Now, houses and businesses all over the world use solar cells to power electrical devices with a wide variety of uses. Solar power is the dominant technology in the renewable energy field, primarily due to its high efficiency and cost-effectiveness. By the early 1990s, photovoltaic conversion had reached an unprecedented new height. Scientists used solar cells constructed of highly conductive photovoltaic materials such as gallium, indium, phosphide and gallium arsenide that increased total efficiency by over 30%. By the end of the century, scientists created a special type of solar cells that converted upwards of 36% of the sunlight it collected into usable energy. These developments built tremendous momentum for not only solar power, but for renewable energy technologies around the world.
Electricity production
Photovoltaics (PV) use silicon solar cells to convert the energy of sunlight into electricity. Operates under the photoelectric effect which results in the emission of electrons. Concentrated solar power (CSP) Uses lenses or mirrors and tracking devices to focus a large area of sunlight into a small beam. Solar power is anticipated to be the world's largest source of electricity by 2050. Solar power plants, such as Ivanpah Solar Power Facility in the Mojave Desert produces over 392MW of power. Solar projects exceeding 1 GW (1 billion watts) are in development and are anticipated to be the future of solar power in the US.
Thermal energy
The sun bombards the earth with billions of charged nanoparticles with an immense amount of energy stored in them. This energy can be used for water heating, space heating, space cooling and process heat generation. Many steam generation systems have adapted to using sunlight as a primary source for heating feed water, a development that has greatly increased the overall efficiency of boilers and many other types of waste heat recovery systems. Solar cookers use sunlight for cooking, drying and pasteurization. Solar distillation is used for water treatment processes to create potable drinking water, which has been an extremely powerful player in providing countries in need with relief efforts through the use of advancing technology.
Economic development
Solar energy conversion has the potential to be a very cost-effective technology. It is cheaper as compared to non-conventional energy sources. The use of solar energy help to increase employment and development of the transportation & agriculture sector. Solar installations are becoming cheaper and more readily available to countries where energy demand is high, but supply is low due to economic circumstances. A 1 GW solar power plant can produce almost 10 times as much power as a fossil fuel combustion power plant that would cost twice as much to establish. Solar power plants have been projected to be the leader of the energy production by the year 2050.
Rural energy access
Solar energy conversion has the potential for many positive social impacts, especially in rural areas that did not previously have grid-based energy access. In many off-grid areas, the solar-electric conversion is the fastest growing form of energy procurement. This is especially true at latitudes within 45° north or south of the Equator, where solar irradiance is more constant throughout the year and where the bulk of the developing world's population lives. From a health perspective, solar home systems can replace kerosene lamps (frequently found in rural areas), which can cause fires and emit pollutants like carbon monoxide (CO), nitric oxides (NOx), and sulfur dioxide (SO2) that adversely affect air quality and can cause impair lung function and increase tuberculosis, asthma, and cancer risks. In such areas, solar energy access has been shown to save rural residents the time and money needed to purchase and transport kerosene, thereby increasing productivity and lengthening business hours.
In addition to energy access, these communities gain energy independence, meaning they are not reliant on a third-party electricity provider. The concept of energy independence is relatively new; for the vast majority of the 20th century, energy analyses were purely technical or financial and did not include social impact analysis. A 1980 study concluded that access to renewable energy would promote values conducive to larger societal benefit as opposed to personal promotion. While some academics argue that historically the parties in control of energy sources are those that create social hierarchies, this type of analysis became less “radical” and more mainstream after the introduction of technologies that enabled solar energy conversion.
Community solar
Solar energy conversion can impact not only just individual customers but whole communities. In a growing number of neighborhoods across America, the conventional model of independent, non-connected rooftop installations is being replaced by community-sized solar microgrids. The idea of “community solar” first became popular because of issues regarding energy storage. Because as of 2018 the wide-scale production of lithium-ion battery and other storage technologies lags the progress of rooftop PV installations, a main issue preventing a nationwide shift to rooftop solar energy generation is the lack of a reliable, single-home storage system that would provide contingencies for night-time energy use, cloud cover, curtailments and blackouts. Additionally, financing solar installations for single homes may be more difficult to secure given a smaller project scope and lack of access to funds. A viable alternative is to connect blocks of homes together in a community microgrid, using more proven large storage installations, thus lowering barriers to solar adoption. In some cases, a microgrid “web” is made by connecting each independent rooftop PV house to a greater storage facility. Other designs, primarily where rooftop installations are not possible, feature a large combined solar array + storage facility located on an adjacent field. As an added social impact, this form of installation makes solar energy economically viable for multi-family homes and historically low income neighborhoods.
Grid defection
A potential socioeconomic drawback associated with solar energy conversion is a disruption to the electric utility business model. In America, the economic viability of regional “monopoly” utilities is based on the large aggregation of local customers who balance out each other's variable load. Therefore, the widespread installation of rooftop solar systems that are not connected to the grid poses a threat to the stability of the utility market. This phenomenon is known as Grid Defection. The pressure on electric utilities is exacerbated by an aging grid infrastructure that has yet to adapt to the new challenges posed by renewable energy (mainly regarding inertia, reverse power flow and relay protection schemes). However, some analysts make the case that with the steady increase in natural disasters (which destroy vital grid infrastructure), solar microgrid installation may be necessary to ensure emergency energy access. This emphasis on contingency preparation has expanded the off-grid energy market dramatically in recent years, especially in areas prone to natural disasters.
Environmental impact
Installations can destroy and/or relocate ecological habitats by covering large tracts of land and promoting habitat fragmentation. Solar facilities constructed on Native American reservations have interrupted traditional practices and have also had negative impact on the local ecosphere.
References
External links
Solar Energy Conversion Calculations research group at Lund University, Sweden
Photoelectrochemistry
Photochemistry
Electrochemistry | Solar energy conversion | [
"Chemistry"
] | 1,866 | [
"Photoelectrochemistry",
"Electrochemistry",
"nan"
] |
54,269,973 | https://en.wikipedia.org/wiki/Shao%20%28unit%29 | A shao () in China, shaku in Japan and jak in Korea, is a unit of volume measurement in East Asia.
One shao equals 1⁄100 sheng.
It is 10 mL (millilitres) in China, 18.04 mL in Japan and 18 mL in Korea.
Shao''' is also a unit of area equal to 0.033 square meters (a hundredth of a tsubo) in Japan and Korea.
The Chinese word shao () means a spoon, or an amount held by a spoon.
China
Japan
Volume
AreaShao' is also a unit of area equal to 0.033 square meters (a hundredth of a tsubo) in Japan.
Korea
The Korean Jak'' (勺) can also be a unit of area, equaling 0.0330579 m2 (0.355832 sq ft.)
For more details on volume measurement, please see Sheng (volume)
See also
Chinese units of measurement
Japanese units of measurement
Korean units of measurement
:zh:中國度量衡
Notes
References
External links
https://ja.wikipedia.org/wiki/勺
https://dictionary.cambridge.org/zht/詞典/漢語-繁體-英語/公勺?q=勺
Units of volume
Units of area
Customary units of measurement | Shao (unit) | [
"Mathematics"
] | 282 | [
"Units of volume",
"Units of area",
"Quantity",
"Customary units of measurement",
"Units of measurement"
] |
54,270,284 | https://en.wikipedia.org/wiki/Hotel%20Manger | The Hotel Manger (pronounced Mang-er as in hangar), renamed the Hotel Madison in 1959, was a hotel in Boston, Massachusetts, United States, that operated from 1930 to 1976. It was attached to North Station and the Boston Garden. In 1983, the building was demolished to make way for the Thomas P. O'Neill Jr. Federal Building.
Development
On November 15, 1927, Homer Loring, chairman of the Boston & Maine Railroad, announced that plans had been finalized for the construction of a new North Station facility, which would include a sports arena, hotel, office building, and distributing terminal. On July 15, 1929, Manger Hotels and the Boston & Maine Railroad announced that the two parties had signed a contract for the construction of the hotel. B&M and Manger would each hold 50% of the stock in the building company and the hotel would be leased to a company owned by Julius Manger. The cost of the building was to be $2.8 million.
Opening
The Hotel Manger opened to the public on August 30, 1930. It was the fifteenth hotel opened by the Manger chain, which also owned hotels in New York City and Chicago. The 17-story hotel contained 500 rooms, a restaurant, private dining rooms, oyster bar, banquet hall/ballroom, barber shop, and beauty salon. At the time of its opening, the Hotel Manger had proportionately more marble than any other building in New England. The top floors offered views of the Charles River, Bunker Hill Monument, and Boston Harbor. The hotel had direct access to the Boston Garden and North Station. George L. Bowles was the hotel's first manager.
The hotel was formally opened on September 27, 1930. The reception was attended by over 200 guests, including Mayor James Michael Curley, Secretary of the Commonwealth Frederic W. Cook, and U.S. Representative John McCormack. Former Boston fire commissioner Theodore A. Glynn was the toastmaster for the event.
From 1934 to 1936, radio station WMEX had its studio in the Hotel Manger.
Notable guests and incidents
Throughout its early years, acts that were performing at the Boston Garden, including Arthur Godfrey, Paul Whiteman, Gene Autry, and Roy Rogers, stayed at the Hotel Manger. Visiting hockey and basketball teams playing at the Garden stayed at the hotel until they switched from rail to air travel. Track athletes participating at the BAA Meet, including Glenn Cunningham, Harrison Dillard, Charles Beetham, and Ralph Boston, also stayed at the Manger.
On July 29, 1932, the Boston Police Department arrested 26 men they believed were involved in the pool and lottery racket. 25 of the 26 men were also charged with suspicion of knowledge of murder. On March 13, 1935, the body of Sturgis H. Hunt, a Quincy, Massachusetts political figure who was a "missing witness" in the removal proceedings against Mayor Charles A. Ross, was found by a chambermaid. Hunt had committed suicide by drinking poison.
On April 5, 1947, at the Boston Bruins annual breakup party, Bill Cowley unexpectedly announced he was leaving hockey because general manager Art Ross left him off of the roster for a post-season exhibition tour of Western Canada and the United States (Cowley's wife was from Vancouver and he wanted to use the trip as a honeymoon). At the time of his retirement, Cowley was the NHL's all-time leading point scorer. On May 14, 1970, Bruins head coach Harry Sinden held a press conference at the hotel to announce he was leaving hockey to enter private business. His announcement came four days after the Bruins defeated the St. Louis Blues in the 1970 Stanley Cup Finals.
On October 25, 1949, the body of Leon G. Whittemore, head of a local chemical company, was found in a third-floor restroom. The medical examiner ruled that Whittemore's death was a suicide by poisoning. On April 1, 1950, the literary scholar F. O. Matthiessen committed suicide by jumping out of a 12th floor window.
On October 21, 1951, groundwork on the Central Artery resulted in the hotel losing its steam supply. The hotel used a steam locomotive to heat the hotel until service was restored. On September 19, 1953, boxing trainer and manager Ray Arcel was critically injured in front of the hotel when he was hit from behind by an assailant wielding a lead pipe. The attack was a warning from the mob, who did not want Arcel to organize a competing television broadcast. The attack was never solved and Arcel remained out of boxing until 1972, when he came out of retirement to train Roberto Durán.
On September 12, 1964, The Beatles stayed at the hotel and held a press conference there.
Ownership changes
In 1958, the Boston and Maine Railroad began negotiations to purchase full ownership of the hotel. The purchase was announced on January 30, 1959. The hotel was renamed as the Hotel Madison by B&M. Julius Manger Jr. stated that the reason for the sale was the company's desire to focus on its motel operations.
In July 1963, B&M sold the hotel, the North Station Industrial Building, and about 17 acres of land behind North Station to Linnell & Cox. Linnell & Cox soon sold the hotel to Dison Corp. for a reported $2 million amid threats that the city would take over the property because of tax defaults.
Closure and demolition
As railroad traffic declined, the neighborhood surrounding North Station lost its importance as a commuter center and the hotel began to suffer financially. In 1973, Dison petitioned to convert the hotel into an elderly housing complex. The Boston Housing Authority supported the proposal and worked to get federal funding. The BHA also considered moving its headquarters to the hotel if the project was completed. However, plans for the housing development fell through. On October 21, 1976, it was announced that due to financial problems, the hotel would close on October 30.
In March 1983, the Boston Redevelopment Authority purchased the hotel from the MSL Reality Trust for $2.2 million. On May 15, 1983, the hotel was demolished by explosives. An estimated 26,000 people observed the implosion, which was also televised live by WNEV. The hotel was demolished in order to make way for the construction of the Thomas P. O'Neill Jr. Federal Building.
References
1930 establishments in Massachusetts
Buildings and structures demolished in 1983
Hotels in Boston
Hotel buildings completed in 1930
1976 disestablishments in Massachusetts
Demolished hotels in the United States
Demolished buildings and structures in Boston
Buildings and structures demolished by controlled implosion
Manger hotels | Hotel Manger | [
"Engineering"
] | 1,354 | [
"Buildings and structures demolished by controlled implosion",
"Architecture"
] |
54,270,305 | https://en.wikipedia.org/wiki/Environmental%20Health%20and%20Preventive%20Medicine | Environmental Health and Preventive Medicine is a peer-reviewed open access medical journal covering preventive medicine and environmental health. It was established in 1996 and is the official journal of the Japanese Society for Hygiene. It was published by BioMed Central until 2021 before taken over by Komiyama Printing Co. Ltd. The editor-in-chief is Yoshihiro Kokubo (National Cerebral and Cardiovascular Center, Osaka, Japan). According to the Journal Citation Reports, the journal has a 2020 impact factor of 3.674, and ranked in the first quartile of the category for public, environmental and occupational health.
References
External links
BioMed Central academic journals
Academic journals established in 1996
Bimonthly journals
English-language journals
Preventive medicine journals
Environmental health journals
Academic journals associated with learned and professional societies of Japan | Environmental Health and Preventive Medicine | [
"Environmental_science"
] | 165 | [
"Environmental science journals",
"Environmental health journals"
] |
54,270,366 | https://en.wikipedia.org/wiki/ARINC%20629 | The ARINC 629 computer bus was introduced in May 1995 and is used on aircraft such as the Boeing 777, Airbus A330 and Airbus A340 as well as the Airbus A320 series.
The ARINC 629 bus operates as a multiple-source, multiple-sink system; each terminal can transmit data to, and receive data from, every other terminal on the data bus. This allows much more freedom in the exchange of data between units in the avionics system. ARINC 629 has the ability to accommodate up to a total of 128 terminals on a data bus and supports a data rate of 2 Mbit/s. It is available in either current or optic mode, over un-shielded, twisted cables.
Each terminal can send 31 word strings, and each word string can have a total of 256 words.
The ARINC 629 data bus was developed by the Airlines Electronic Engineering Committee (AEEC) to replace the ARINC 429 bus.
The ARINC 629 data bus was based on the Boeing DATAC bus.
A unique feature of ARINC 629 is it uses inductive couplers to connect the RTs (Remote Terminals) to the bus.
References
Computer buses
Avionics
Computer-related introductions in 1995
ARINC standards
Serial buses | ARINC 629 | [
"Technology"
] | 262 | [
"Avionics",
"Aircraft instruments"
] |
54,270,667 | https://en.wikipedia.org/wiki/Excited%20state%20intramolecular%20proton%20transfer | Excited state intramolecular proton transfer (ESIPT) is a process in which photoexcited molecules relax their energy through tautomerization by transfer of protons. Some kinds of molecules could have different minimum-energy tautomers in different electronic states, and if the molecular structure of minimum-energy tautomer in the excited state is proton-transferred geometry between neighboring atoms, proton transfer in excited state can occur. The tautomerization often takes the form of keto-enol tautomerism.
Characteristic
Since a proton-transferred geometry is usually the minimum-energy tautomer only in the excited state and relatively unstable in the ground state, molecules that have ESIPT character may show extraordinarily larger Stokes shift than common fluorescent molecules, or exhibit dual fluorescence that shorter-wavelength one comes from the original tautomer and longer-wavelength one from proton-transferred tautomer. However, there are some exceptional cases where ESIPT molecules have no dual luminescence or significantly red-shifted emission from proton-transferred tautomer, from various reasons.
Rate of ESIPT process may slow down by deuterium substitution of hydrogen that is transferred in ESIPT, because the deuteration increases only mass of the transferred significantly while do not change electrostatic potential in the molecule substantially. However the amount of rate change may lie in the range of 1~50, depending on the shape and size of potential energy surfaces of the molecule.
Application
Based on characteristic that molecules usually have extraordinarily larger Stokes shift when ESIPT occurs, various applications have been developed using red-shifted fluorescence. Applications include turn-on photoluminescence sensor, photochromic, non-destructive optical memory, and white-light emitting materials.
Because phenol does not form a ketal under normal conditions because it does not tautomerize to any useful extent; however under ESIPT in the presence of an alcohol, e.g. ethylene glycol, it became possible to trap 1,4-Dioxaspiro[4.5]deca-6,8-diene [23783-59-7].
References
Enols
Photochemistry | Excited state intramolecular proton transfer | [
"Chemistry"
] | 458 | [
"Enols",
"Functional groups",
"nan"
] |
54,270,925 | https://en.wikipedia.org/wiki/Skeletocutis%20diluta | Skeletocutis diluta is a species of poroid crust fungus in the family Polyporaceae. It was first described by Mario Rajchenberg in 1983 as a variety of Skeletocutis nivea. Rajchenberg and Alex David promoted the taxon to independent species status in 1992. The type specimen was collected in Puerto Esperanza, Misiones (Argentina), where it was found growing on Pinus taeda logs in a subtropical forest. It has since been found in Gabon. Skeletocutis diluta has effused-reflexed fruit bodies, meaning they are crust-like with a margin that is extended and bent backwards. It has small allantoid (sausage-shaped) spores measuring 3.1–3.5 by 0.5–0.8 μm. It features a dimitic hyphal system (containing both generative and skeletal hyphae), but the skeletal hyphae dissolve in solution of potassium hydroxide.
References
Fungi described in 1983
Fungi of Africa
Fungi of Argentina
diluta
Fungus species | Skeletocutis diluta | [
"Biology"
] | 220 | [
"Fungi",
"Fungus species"
] |
54,271,259 | https://en.wikipedia.org/wiki/Abell%202152 | Abell 2152 is a bimodal galaxy cluster and one of three clusters comprising the Hercules Supercluster. It contains 3 BCGs; the S0 lenticular UGC 10204, the pair UGC 10187, and the SA0 unbarred lenticular CGCG 108-083. In total there are 41 galaxies which are confirmed to be members of the cluster. The cluster is classified as a Bautz-Morgan type III and Rood-Sastry class F cluster, indicating morphological irregularity and perhaps dynamical youth. It is receding from the Milky Way galaxy with a velocity of 12385 km/s.
Abell 2152 is the nearest cluster in which significant gravitational lensing of a background source has been observed. The arc-like background galaxy, known as J160529.52+162633.9, lies at a redshift z=0.1423 and has been magnified by a factor ~1.9 due to the lensing effect.
References
Hercules (constellation)
2152
Abell richness class 1
Galaxy clusters
Hercules Superclusters | Abell 2152 | [
"Astronomy"
] | 230 | [
"Astronomical objects",
"Galaxy clusters",
"Hercules (constellation)",
"Constellations"
] |
54,272,335 | https://en.wikipedia.org/wiki/Technical%20Aesthetics | Technical Aesthetics (Техническая эстетика in Russian) was a Soviet monthly magazine published between January 1964 and July 1992 dedicated to questions of design with peak distribution of 30,000 copies. It was edited by the VNIITE, the All-Union Technical Aesthetics Research Institute. Some of the topics it covered were the history, theory and practice of design in Russia and abroad, ergonomics, art and design education, and reviews of design exhibitions and books. The magazine regularly exposed Western design trends and innovations, which were often compared with their Soviet counterparts. It also rehabilitated the memory of movements such as Russian constructivism, which had been condemned by Stalin in favour of Socialist realism, even if they set the foundations of Russian design in the early 1920s.
According to art historian Alexandra Chiriac, the term technical aesthetics was invented in Russia in the 1960s to speak about the field of design, which wasn't really developed in the country at the time, and which was promoted through the VNIITE research institute and the Technical Aesthetics magazine.
References
External links
Scanned issues from 1988 of the Technical Aesthetics magazine.
Magazines published in the Soviet Union
Design magazines
Product design | Technical Aesthetics | [
"Engineering"
] | 247 | [
"Product design",
"Design",
"Design magazines"
] |
44,220,855 | https://en.wikipedia.org/wiki/Pigment%20Red%20149 | Pigment Red 149 is an organic compound that is used as a pigment. Structurally, it is a derivative of perylene, although it is produced from perylenetetracarboxylic dianhydride by derivatization with 3,5-dimethylaniline.
References
Perylene dyes
Vat dyes
Imides | Pigment Red 149 | [
"Chemistry"
] | 72 | [
"Functional groups",
"Organic compounds",
"Imides",
"Organic compound stubs",
"Organic chemistry stubs"
] |
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