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59,416,143 | https://en.wikipedia.org/wiki/Prison%20Special | The "Prison Special" was a train tour organized by suffragists who, as members of the Silent Sentinels and other demonstrations, had been jailed for picketing the White House in support of passage of the federal women's suffrage amendment. In February 1919, 26 members of the National Woman's Party boarded a chartered train they dubbed the "Democracy Limited" in Washington, D.C. They visited cities across the country where they spoke to large crowds about their experiences as political prisoners at Occoquan Workhouse, and were typically dressed in their prison uniforms. The tour, which concluded in March 1919, helped create support for the ratification effort that ended with the adoption of the Nineteenth Amendment on August 26, 1920.
Background
In the summer of 1917, members of the National Woman's Party (NWP) began to stage protests outside the White House in Washington, D.C., demanding the vote for women. Over the course of the summer and fall, many of the women were arrested, often on charges of obstructing traffic, and fined. When they refused to pay those fines, they were jailed. At first, penalties were relatively light, but as the Silent Sentinels persisted in their vigil, sentences became more harsh. In July and August of that year, women were sentenced to unusually harsh sentences of sixty days and many were imprisoned at Occoquan Workhouse in Virginia. In their belief that they were political prisoners, they refused to eat prison food, to perform work, or to wear the rough-cut prison uniforms provided to prisoners. By the fall, three of the women who had been participating in a hunger strike were subjected to forced feedings.
Public pressure forced officials to release the women held at Occoquan, but arrests continued throughout 1918 as the NWP intensified its lobbying efforts on behalf of women's suffrage. At the beginning of 1919, members of the NWP lit watch fires at both the White House and in nearby Lafayette Park, prompting another wave of arrests. Ultimately, 168 women would serve prison time. In February 1919, the woman's suffrage amendment was defeated by just one vote in the Senate. To secure public support and pressure legislators into passing the amendment before the end of the congressional session in March, the NWP launched a campaign they dubbed "From Prison to People," a three-week train tour across the United States.
The tour
Designed to educate the public about the "brutal and lawless measures of the Administration to suppress suffrage," the "Prison Special" train tour stopped at 16 cities across the United States to highlight the arrest, incarceration, and ill-treatment of women who had participated in protests supporting women's suffrage. The NWP members aboard the chartered train (nicknamed "The Democracy Limited") included veteran organizers Abby Scott Baker, Lucy Gwynne Branham, Lucy Burns, Mary Nolan (the NWP's "oldest picket"), Vida Milholland, Agnes Morey and Mabel Vernon.
To make their argument, they gave speeches from rented halls, train platforms, and automobiles, they sang jail songs from their time in prison, including "The Women's Marseillaise", and played the comb, they reenacted their arrests through dramatic readings, and they distributed pamphlets, including "Jailed for Freedom" (not to be confused with Doris Stevens' work published in 1920 under the same title). Perhaps most significantly, they dressed in replicas of their prison uniforms—described in the NWP publication, The Suffragist, as "calico wrappers designed exactly after the pattern of those which they were forced to wear in the work-house, thereby making the accounts of their experiences in the jail more vivid."
The tour was expensive and the cost—about $20,000—was funded by state branches of the NWP and individual donations from members. Louisine Havemeyer, a wealthy New York socialite and suffragist, also donated $1500 to the cause. William B. Thompson, a businessman, philanthropist, and supporter of women's suffrage, paid for the literature distributed during the tour. Ella Riegel managed tour logistics and Abby Scott Baker served as publicist.
Itinerary
The Prison Special left Union Station in Washington, D.C., on February 15, 1919, the anniversary of the birthday of women's rights activist Susan B. Anthony. The published itinerary included stops in the following cities:
Charleston, South Carolina (February 16–17)
Jacksonville, Florida (February 18–19)
Chattanooga, Tennessee (February 20–21)
New Orleans, Louisiana (February 22–23)
San Antonio, Texas (February 24)
Los Angeles, California (February 26–27)
San Francisco, California (February 28-March 1)
Denver, Colorado (March 3–4)
Chicago, Illinois (March 5–7)
Milwaukee, Wisconsin (March 6)
Detroit, Michigan (March 7)
Syracuse, New York (March 8–9)
Boston, Massachusetts (March 9–10)
Hartford, Connecticut (March 10)
New York, New York (March 10)
The route moved systematically through the Southern states, where the NWP hoped to sway the sentiment of the Democratic Party, which had resisted the cause of women's suffrage, on to the Western states, where the NWP expected to rally women already enfranchised by their states to the cause of a federal amendment, and through the Northern states and the Northeast, ending in New York City. In addition to its published itinerary, the Prison Special also made several unscheduled stops which the women took full advantage of. In El Paso, Texas, a "flat wheel" on the Prison Special car forced an overnight stay. The El Paso Herald reports that Lucy Burns, Amelia Himes Walker Elizabeth McShane, and Sue Shelton White "preached the doctrine of suffrage" while other suffragists distributed literature to the gathered crowd. They carried flags with the suffrage colors of gold, purple, and white and stood on a step so that they could speak through the train platform's grill, which mimicked the bars of a prison. In an interview with the newspaper, Abby Scott Baker provided some insight into the women's experience as public speakers: "It is not easy to begin speaking on the street", she said. "Even though you are in the midst of a crowd, you have to begin talking to the air. But when you start out 'Ladies and gentlemen, the cause of liberty is sacred,' some of them will stop to see what is going on and, if you keep on, you will get them interested".
The participants of the Prison Special tour, all women who had served time in jail for supporting suffrage, included:
Pauline Adams
Edith Ainge
Berthe Arnold
Lillian Ascough
Abby Scott Baker
Josephine Bennett
Lucy Gwynne Branham
Lucy Burns
Palys Chevrier
Sarah T. Colvin
Lucy Hyde Ewing
Estelle Eylward
Gladys Greiner
Louisine Havemeyer
Mrs. Raymond Hunter
Mary Hall Ingham
Willie Grace Johnson
Elizabeth McShane
Vida Milholland
Agnes Morey
Mary Nolan
Ella Riegel
Elizabeth Selden Rogers
Gertrude Shaw
Mabel Vernon
Amelia Himes Walker
Cora Weeks
Sue Shelton White
Mary Winsor
Tactics
Some of the women aboard the Prison Special had some experience with train tours, having worked with the Congressional Union for Woman Suffrage in 1916 to organize the Suffrage Special. By 1919, the more radical NWP declared that this tour "would endeavor to acquaint the country with the lawless and brutal lengths to which the [Wilson] Administration has gone to suppress the lawful agitation for suffrage." To pursue that goal, the women would detail the time they spent in prison for what they insisted was peaceable assembly. Initially, the women wanted to paint the train car they would travel in with prison bars, but the Railway Administration would "not allow the painting of the cars to look like prison cells, nor any other insignia denoting the character and purpose of the car."
Instead, the women opted to highlight their prison experiences by appearing in public dressed in their prison uniforms (or replicas of those uniforms), which they once referred to as the "cloth of guilt" and which had been described as "the clumsiest sort of clothing--heavy, shapeless dresses; underclothing of unbleached muslin and woolen stockings--garments that are hot in the summer and cold in winter, and given to prisoners regardless of season." Two years after their incarceration at Occoquan and at a city jail in Washington, D.C., the women on the Prison Special hoped to use these same uniforms as evidence of the hardship of their struggle. While the adoption of the prison uniform helped to dramatize the struggle for women's suffrage, scholars also point to the ways in which the status of the "Prison Specialists" as elite white women was foregrounded. Newspaper accounts often remarked on their "refinement" and "education" and noted that they were "women of wealth who have chosen to humiliate themselves that attention may be drawn to the cause for which they are fighting." Journalist Carolyn Vance Bell wrote that the women on the Prison Special "were primed to unfold a harrowing tale...[about] the secrets of the prison house which...are guaranteed to freeze the feminine blood..." Such representations suggested that the injuries to these women—as opposed to working-class women or to African-American women—were injuries that mattered.
While programs varied from stop to stop, certain speakers were consistently featured. Louisine Havemeyer regularly spoke first, and was introduced as a grandmother of 11 children and one of the richest women in New York. She often spoke about the cause of women's suffrage being a just one and newspaper reports commented on her dignity and poise. Abby Scott Baker would often speak next; other speakers included Lucy Burns, Mary Winsor, who had spent 66 days in jail, and Lucy Branham. Often, while one woman was speaking, others, dressed in their prison clothes, would stand silently behind her.
In addition to distributing the pamphlet "Jailed for Freedom", the women also handed out a list of grievances against the Wilson Administration, noting that President Wilson "speaks for" women's suffrage, but "does nothing to promote it." A political cartoon drawn by Nina Allender, the official cartoonist for the NWP, shows a suffragist holding a copy of the "Senate Record" and carrying luggage labeled "N.W.P. Democracy Limited" about to board the Prison Special. During the tour, the women held mass meetings, often greeted by delegations of women—NWP members, club women, and others—at local hotels. The women on the Prison Special also used "motion pictures", likely a magic lantern show, as another visual way to represent their experiences of incarceration.
Participants in the Prison Special tour were capable publicists. In an article for Scribner's Magazine, Louisine Havemeyer recalls being asked to take a publicity photo with a police captain because "it will make such a good cut for the newspapers." She was careful to make sure the captain was shaking her hand when the picture was taken so that no one would think she was being arrested on tour.
Responses
The Prison Special was a draw for crowds: Abby Scott Baker reported that the police estimated that 2,000 people attended the stop in Charleston, South Carolina. But their reception was not always enthusiastic. Some newspapers reported the meetings encouraged "decidedly unnatural feminine sentiments." Other suffragists wanted to separate themselves from the more radical tactics of the NWP, whose members had burned an effigy of President Wilson the previous year. In Columbia, South Carolina, the mayor warned the women that "disloyal utterances would not be tolerated." The Equal Franchise League in El Paso, Texas, declared that it was "not in sympathy with the militant suffraget class." Often, however, the crowds were in sympathy with the tactics of the Prison Specialists, booing and hissing their treatment and crying "Shame! Shame on our government!"
Aftermath
Just three months after the conclusion of the Prison Special tour, Congress voted for passage of the 19th Amendment in June 1919. State-by-state ratification of the 19th Amendment would end in the successful adoption of the amendment a year later, in August 1920. The NWP, along with several members of the Prison Special tour, would continue the fight for women's rights by supporting the Equal Rights Amendment, a struggle that continues today.
See also
Suffrage Special
References
External links
Political cartoon drawn by Nina Allender
Political activism
Women's suffrage in the United States
History of voting rights in the United States
History of women in the United States
Progressive Era in the United States
Trains
1919 protests
Feminist protests in the United States
Women's suffrage advocacy groups in the United States | Prison Special | Technology | 2,641 |
6,088,729 | https://en.wikipedia.org/wiki/Jacket%20matrix | In mathematics, a jacket matrix is a square symmetric matrix of order n if its entries are non-zero and real, complex, or from a finite field, and
where In is the identity matrix, and
where T denotes the transpose of the matrix.
In other words, the inverse of a jacket matrix is determined by its element-wise or block-wise inverse. The definition above may also be expressed as:
The jacket matrix is a generalization of the Hadamard matrix; it is a diagonal block-wise inverse matrix.
Motivation
As shown in the table, i.e. in the series, for example with n=2, forward: , inverse : , then, . That is, there exists an element-wise inverse.
Example 1.
:
or more general
:
Example 2.
For m x m matrices,
denotes an mn x mn block diagonal Jacket matrix.
Example 3.
Euler's formula:
, and .
Therefore,
.
Also,
,.
Finally,
A·B = B·A = I
Example 4.
Consider be 2x2 block matrices of order
.
If and are pxp Jacket matrix, then is a block circulant matrix if and only if , where rt denotes the reciprocal transpose.
Example 5.
Let and , then the matrix is given by
,
⇒
where U, C, A, G denotes the amount of the DNA nucleobases and the matrix is the block circulant Jacket matrix which leads to the principle of the Antagonism with Nirenberg Genetic Code matrix.
References
[1] Moon Ho Lee, "The Center Weighted Hadamard Transform", IEEE Transactions on Circuits Syst. Vol. 36, No. 9, PP. 1247–1249, Sept. 1989.
[2] Kathy Horadam, Hadamard Matrices and Their Applications, Princeton University Press, UK, Chapter 4.5.1: The jacket matrix construction, PP. 85–91, 2007.
[3] Moon Ho Lee, Jacket Matrices: Constructions and Its Applications for Fast Cooperative Wireless Signal Processing, LAP LAMBERT Publishing, Germany, Nov. 2012.
[4] Moon Ho Lee, et. al., "MIMO Communication Method and System using the Block Circulant Jacket Matrix," US patent, no. US 009356671B1, May, 2016.
[5] S. K. Lee and M. H. Lee, “The COVID-19 DNA-RNA Genetic Code Analysis Using Information Theory of Double Stochastic Matrix,” IntechOpen, Book Chapter, April 17, 2022. [Available in Online: https://www.intechopen.com/chapters/81329].
External links
Technical report: Linear-fractional Function, Elliptic Curves, and Parameterized Jacket Matrices
Jacket Matrix and Its Fast Algorithms for Cooperative Wireless Signal Processing
Jacket Matrices: Constructions and Its Applications for Fast Cooperative Wireless Signal Processing
Matrices | Jacket matrix | Mathematics | 601 |
297,446 | https://en.wikipedia.org/wiki/Gelfand%E2%80%93Naimark%E2%80%93Segal%20construction | In functional analysis, a discipline within mathematics, given a -algebra , the Gelfand–Naimark–Segal construction establishes a correspondence between cyclic -representations of and certain linear functionals on (called states). The correspondence is shown by an explicit construction of the -representation from the state. It is named for Israel Gelfand, Mark Naimark, and Irving Segal.
States and representations
A -representation of a -algebra on a Hilbert space is a mapping
from into the algebra of bounded operators on such that
is a ring homomorphism which carries involution on into involution on operators
is nondegenerate, that is the space of vectors is dense as ranges through and ranges through . Note that if has an identity, nondegeneracy means exactly is unit-preserving, i.e. maps the identity of to the identity operator on .
A state on a -algebra is a positive linear functional of norm . If has a multiplicative unit element this condition is equivalent to .
For a representation of a -algebra on a Hilbert space , an element is called a cyclic vector if the set of vectors
is norm dense in , in which case π is called a cyclic representation. Any non-zero vector of an irreducible representation is cyclic. However, non-zero vectors in a general cyclic representation may fail to be cyclic.
The GNS construction
Let be a -representation of a -algebra on the Hilbert space and be a unit norm cyclic vector for . Then
is a state of .
Conversely, every state of may be viewed as a vector state as above, under a suitable canonical representation.
The method used to produce a -representation from a state of in the proof of the above theorem is called the GNS construction.
For a state of a -algebra , the corresponding GNS representation is essentially uniquely determined by the condition, as seen in the theorem below.
Significance of the GNS construction
The GNS construction is at the heart of the proof of the Gelfand–Naimark theorem characterizing -algebras as algebras of operators. A -algebra has sufficiently many pure states (see below) so that the direct sum of corresponding irreducible GNS representations is faithful.
The direct sum of the corresponding GNS representations of all states is called the universal representation of . The universal representation of contains every cyclic representation. As every -representation is a direct sum of cyclic representations, it follows that every -representation of is a direct summand of some sum of copies of the universal representation.
If is the universal representation of a -algebra , the closure of in the weak operator topology is called the enveloping von Neumann algebra of . It can be identified with the double dual .
Irreducibility
Also of significance is the relation between irreducible -representations and extreme points of the convex set of states. A representation π on is irreducible if and only if there are no closed subspaces of which are invariant under all the operators other than itself and the trivial subspace .
Both of these results follow immediately from the Banach–Alaoglu theorem.
In the unital commutative case, for the -algebra of continuous functions on some compact , Riesz–Markov–Kakutani representation theorem says that the positive functionals of norm are precisely the Borel positive measures on with total mass . It follows from Krein–Milman theorem that the extremal states are the Dirac point-mass measures.
On the other hand, a representation of is irreducible if and only if it is one-dimensional. Therefore, the GNS representation of corresponding to a measure is irreducible if and only if is an extremal state. This is in fact true for -algebras in general.
To prove this result one notes first that a representation is irreducible if and only if the commutant of , denoted by , consists of scalar multiples of the identity.
Any positive linear functionals on dominated by is of the form
for some positive operator in with in the operator order. This is a version of the Radon–Nikodym theorem.
For such , one can write as a sum of positive linear functionals: . So is unitarily equivalent to a subrepresentation of . This shows that π is irreducible if and only if any such is unitarily equivalent to , i.e. is a scalar multiple of , which proves the theorem.
Extremal states are usually called pure states. Note that a state is a pure state if and only if it is extremal in the convex set of states.
The theorems above for -algebras are valid more generally in the context of -algebras with approximate identity.
Generalizations
The Stinespring factorization theorem characterizing completely positive maps is an important generalization of the GNS construction.
History
Gelfand and Naimark's paper on the Gelfand–Naimark theorem was published in 1943. Segal recognized the construction that was implicit in this work and presented it in sharpened form.
In his paper of 1947 Segal showed that it is sufficient, for any physical system that can be described by an algebra of operators on a Hilbert space, to consider the irreducible representations of a -algebra. In quantum theory this means that the -algebra is generated by the observables. This, as Segal pointed out, had been shown earlier by John von Neumann only for the specific case of the non-relativistic Schrödinger-Heisenberg theory.
See also
Cyclic and separating vector
KSGNS construction
References
William Arveson, An Invitation to C*-Algebra, Springer-Verlag, 1981
Kadison, Richard, Fundamentals of the Theory of Operator Algebras, Vol. I : Elementary Theory, American Mathematical Society. .
Jacques Dixmier, Les C*-algèbres et leurs Représentations, Gauthier-Villars, 1969.English translation:
Thomas Timmermann, An invitation to quantum groups and duality: from Hopf algebras to multiplicative unitaries and beyond, European Mathematical Society, 2008, – Appendix 12.1, section: GNS construction (p. 371)
Stefan Waldmann: On the representation theory of deformation quantization, In: Deformation Quantization: Proceedings of the Meeting of Theoretical Physicists and Mathematicians, Strasbourg, May 31-June 2, 2001 (Studies in Generative Grammar) , Gruyter, 2002, , p. 107–134 – section 4. The GNS construction (p. 113)
Shoichiro Sakai, C*-Algebras and W*-Algebras, Springer-Verlag 1971.
Inline references
Functional analysis
C*-algebras
Axiomatic quantum field theory
ru:Алгебраическая квантовая теория | Gelfand–Naimark–Segal construction | Mathematics | 1,416 |
8,421,235 | https://en.wikipedia.org/wiki/Transport%20maximum | In physiology, transport maximum (alternatively Tm or Tmax) refers to the point at which increase in concentration of a substance does not result in an increase in movement of a substance across a cell membrane.
In renal physiology, the concept of transport maximum is often discussed in the context of glucose and PAH.
For both substances (as with all substances), the quantity excreted can be determined with the following equation:
excretion = (filtration + secretion) - reabsorption
The proximal convoluted tubule of the nephron has protein channels that reabsorb glucose, and others that secrete para-aminohippuric acid (PAH). However, its ability to do so is proportionate to the channel proteins available for the transport.
Glucose is not secreted, so excretion = filtration - reabsorption. Both filtration and reabsorption are directly proportional to the concentration of glucose in the plasma. However, while the average maximum reabsorption is about 375 mg/min in healthy individuals, filtration has effectively no limit (within reasonable physiological ranges.) Therefore, if the concentration rises above 375 mg/min, the body cannot retain all the glucose, leading to glucosuria.
PAH is not reabsorbed and is secreted, so excretion = filtration + secretion. As with glucose, the transfer is at the proximal tubule, but in the opposite direction: from the peritubular capillaries to the lumen. At low levels, all the PAH is transferred, but at high levels, the transport maximum is reached, and the PAH takes longer to clear.
In practice, the transport maximum is not all-or-nothing. As the concentration approaches the transport maximum, some of the channels are overwhelmed before others are. For example, with glucose, some sugar appears in the urine at levels much lower than 300 mg/dL. The point at which the effects start to appear is called "threshold", and the difference between threshold and transport maximum is called "splay".
References
Circulatory system | Transport maximum | Biology | 448 |
16,671,094 | https://en.wikipedia.org/wiki/Fish%20toxins | Fish toxins or fish stupefying plants have historically been used by many hunter gatherer cultures to stun fish, so they become easy to collect by hand. Some of these toxins paralyse fish, which can then be easily collected. The process of documenting many fish toxins and their use is ongoing, with interest in potential uses from medicine, agriculture, and industry.
Theory
Use of the herbal fish poisons has been documented in a number of sources involving catching fish from fresh and sea water.
Tribal people historically used various plants for medicinal and food exploitation purposes. Use of fish poisons is a very old practice in the history of humankind. In 1212 AD, King Frederick II prohibited the use of certain plant piscicides, and by the 15th century, similar laws had been decreed in other European countries, as well. All over the globe, indigenous people use various fish poisons to kill fish, including America and among Tarahumara Indians.
Herbal fish-stupefying agents are proven means of fishing. Many of these plants have been used for a long time by local people, and have been tested and found to have medicinal properties, such as Careya arborea, which is used as analgesic and antidiarrheal. Some of the plants, such as C. collinus, are traditional poisons used in the different part of the country. Bark extracts of Lannea coromandelica caused lysis of cell membranes followed by fragmentation of cellular materials.
Example plants
In Africa, the closely related families of Caesalpiniaceae, Mimosaceae, and Papilionaceae, and a large number of Euphorbiaceae account for most fish poisons.
California buckeye (Aesculus californica) is a widespread tree in the California oak woodlands and chaparral. The large orange-colored fruit is leached in warm water, with the resultant aesculin mixture then applied to pools in slow-moving streams to stun fish.
Many of California's Native American tribes traditionally used the soaproot species, Chlorogalum pomeridianum, which contains saponin, as a fish poison. They would pulverize the roots, mix in water to create a foam, and then add the suds to a stream. This would kill or incapacitate the fish, which could be gathered easily from the surface of the water. The Lassik, Luiseño, Yuki, Yokuts, Chilula, Wailaki, Miwok, Kato, Mattole, Nomlaki, and Nishinam tribes used this technique.
California Natives also used crushed leaves of Croton setiger as a fish toxin much like soaproot and passed this technique on to later immigrants.
Indigenous peoples of the Southeastern Woodlands engaged in fish poisoning, trapping fish with dams or weirs before deploying incapacitating poisons. Several of the toxic plants utilized include crushed black walnut (Juglans nigra), horse chestnut (Aesculus hippocastanum), and Viburnum. Members of the Eastern Band of Cherokee Indians have fished with poison into the 20th century.
The extremely toxic (to humans), tropane alkaloid-containing shrub Latua pubiflora (family Solanaceae) was used formerly by the Huilliche people of the Los Lagos Region of southern Chile to catch fish in slow-flowing rivers - either alone or in combination with the juice of Drimys winteri (Winteraceae) - the latter being a fish poison in its own right. The poison did not kill the fish outright, but merely made them torpid enough to be caught easily.
Olax in the family Olacaceae is a climber with compound, dark-green leaves and white bark. This is the most extensively used fish poison among the Gondi of India. Typically in summer, the leaves of this plant are dried and powdered. About 1 kg of powder is mixed into water about deep in ponds, usually in the summer. Fish are stunned by the poison and rise to the surface, where they are easily collected by hand. If stunned fish are immediately reintroduced into clean water, they become active. To get good results from the Olax (or korkat), the temperature needs to be high.
Strychnos lucida in the family Loganiaceae was used by Indigenous Australians as a fish toxin.
Acacia auriculiformis, Acacia holosericea, Tephrosia phaeosperma and Tephrosia polyzyga in the family Fabaceae were used by Indigenous Australians as fish toxins.
Owenia vernicosa in the family Meliaceae was used by Indigenous Australians as a fish toxin.
Atalaya hemiglauca in the family Sapindaceae was used by Indigenous Australians as a fish toxin.
Barringtonia acutangula and Planchonia careya in the family Lecythidaceae were used by Indigenous Australians as fish toxins.
Careya arborea in the family Lecythidaceae is a large deciduous tree with simple large obovate leaves, large fruit and dark gray bark found in parts of Asia. The root bark is crushed and mixed in water. Upon its admixture, water blackens.
Cleistanthus collinus in the family Euphorbiaceae (odcha in Gondi) is a medium-sized tree mainly found around villages in Sri Lanka. Young tender shoots of this species are used for fish stunning. The shoots are crushed with water on a stone, and a paste is mixed into the water.
Lannea coromandelica in the family Anacardiaceae is a medium-sized to large deciduous tree with a spreading crown and stout branches. The leaves are compound, the bark is whitish or gray, and it has small, yellowish or purplish flowers. Flowers and fruits appear between February and June. Fruits (red, compressed, reniform, and single-seeded) of this plant are crushed and mixed in water. It is abundant in the Mendha-Lekha forest of Maharashtra.
Costus speciosus in the family Costaceae is an erect, succulent herb, up to 2.7 m tall and with a tuberous rootstock, which is crushed and mixed in water for fish stunning in India. Apart from its use as a fish stunning agent in Mendha, tubers of bese mati are consumed after boiling.
Madhuca indica in the family Sapotaceae is a large tree, with seeds yielding edible oil. After the removal of the oil from seeds, the remaining cake is used for fish stunning in India. This cake is locally known as gara-dhep. The cake is boiled in water and mixed into water. A 0.5-kg cake is sufficient for a 100 ft2 pond. It is an effective agent, but fish usually die from its application.
Nauclea orientalis is a large tree in the family Rubiaceae found in Southeast Asia and Australasia. It is commonly known as the Leichhardt tree. The bark is used in creating fish poison.
Pterocarpus marsupium in the family Fabaceae is a large tree with simple leaves found in South Asia and Nepal. Its gray bark is used for fish poisoning, crushed and mixed in water.
Verbascum thapsus, a widespread introduced species from Europe, contains rotenone in its leaves and seeds and has been used for fish poisoning.
See also
Cyanide fishing
Rotenone
References
Fishing techniques and methods | Fish toxins | Environmental_science | 1,539 |
27,395,982 | https://en.wikipedia.org/wiki/Automated%20Imaging%20Association | Automated Imaging Association (AIA) is the world's largest machine vision trade group. AIA has more than 350 members from 32 countries, including system integrators, camera, lighting and other vision components manufacturers, vision software providers, OEMs and distributors. The association's headquarters is located in Ann Arbor, Michigan. Now part of the A3; the Association for Advancing Automation AIA joins RIA; Robotic Industries Association, MCMA, Motion Control & Motor Association and A3 Mexico to form one of the largest collaborative trade association. All organizations offer industry training, news and member benefits.
Standards
The Camera Link, Camera Link HS, GigE Vision, USB3 Vision and CoaXPress communication protocols are maintained and administered by the Automated Imaging Association (AIA).
Camera Link, Camera Link HS, GigE Vision, USB3 Vision, CoaXPress are all available for public download on their Vision Online website. Manufacturers of vision products using the standard must license the standard.
Notable members
Sony is among the multi-billion dollar member companies in the AIA. Cognex Corporation and National Instruments are also two big names in the machine vision industry that are members of the AIA. In 2010, 51% of the members are from North America, 30% are from Europe, 15% are from Eastern Asia, less than 1% are from South America, 2% are from Western Asia, less than 1% are from Southern Asia, 1% are from Southeastern Asia and less than 1% of the members are from Australia.
References
Technology trade associations
Organizations based in Ann Arbor, Michigan
Computer vision
Organizations established in 1984
1984 establishments in the United States | Automated Imaging Association | Engineering | 337 |
7,383,487 | https://en.wikipedia.org/wiki/Oospore | An oospore is a thick-walled sexual spore that develops from a fertilized oosphere in some algae, fungi, and oomycetes. They are believed to have evolved either through the fusion of two species or the chemically induced stimulation of mycelia, leading to oospore formation.
In Oomycetes, oospores can also result from asexual reproduction, by apomixis. These haploid, non-motile spores are the site of meiosis and karyogamy in oomycetes.
A dormant oospore, when observed under an electron microscope, has led researchers to draw conclusion that there is only a single central globule with other storage bodies surrounding it.
References
Reproduction | Oospore | Biology | 157 |
71,866,432 | https://en.wikipedia.org/wiki/Myriostoma%20capillisporum | Myriostoma capillisporum is a fungal species in the family Geastraceae. Basidiocarps resemble earthstars, but the spore sac is supported by multiple columns (instead of a single column) and has multiple ostioles instead of a single, apical ostiole. The fungus was originally described as a variety of Myriostoma coliforme, based on the distinctive and conspicuous ornamentation of its basidiospores. Recent molecular research, based on cladistic analysis of DNA sequences, has shown that it is a separate species, so far only known from South Africa.
References
fungi of Africa
Geastraceae
Fungus species | Myriostoma capillisporum | Biology | 140 |
1,336,667 | https://en.wikipedia.org/wiki/Meteor%20%28rocket%29 | Meteor is a family of Polish sounding rockets series. The Meteor rockets were built between 1963 and 1974.
Meteor was a series of one- and two-stage meteorological rockets using solid fuel, constructed for the research of the upper layers of the atmosphere, wind directions and forces from 18 km to more than 50 km above the Earth's surface. These rockets were designed by Polish engineers of Warsaw Aviation Institute (among them was Professor Jacek Walczewski and engineer Adam Obidziński) and had been produced by WZK-Mielec.
History
The first launch site of the sounding rockets in Poland was Błędowska Desert, where between 1958 and 1963, rockets of different types had been launched; among others RD and Rasko. During a flight, a biological experiment with earlier trained two white mouses was conducted (the RM-2D rocket achieved the altitude of 1,580 meters).
From 1965 until April 1970, the Meteor-1 rockets had been launched from a "spaceport" located 5 km from Ustka. This programme had been continued to 1974, when rockets were bearing out from the area of experimental center founded there during the years of the Second World War, located on west side of Łeba. Currently, it is preserved in the museum (the starting place with the ramp and the radar bases).
There were 224 flights of "Meteor-1" rocket series (including prototypes). The valuable data both meteorological and connected with rocket techniques were collected and analyzed as the result of these researches.
The "Meteor-1", "Meteor-2H" and "Meteor 2K" (the largest civilian rocket developed in Poland) were single-stage rockets. The "Meteor-3" was a two-stage rocket, developed from "Meteor 1".
Meteor rockets had been launched from Łeba and Ustka. Five Meteor rockets missions were conducted around 1970 from Zingst, in East Germany. The programme of flights of Meteor-2 was finished during the same year, when Poland started to participate in Interkosmos research, using the Vertical rockets, which were derived from R-14 missile.
Meteor-1
One stage, but two units rocket called "Meteor-1" had the length of 2,470 mm and the initial mass of 32.5 kg. The flight lasted for 80 seconds and reaching at the peak altitude of 36.5 km. The motor ignite for 2–3 seconds and reached the maximum velocity of 1,100 meters per seconds. In 1965, 6 rockets of "Meteor-1" type was launched and after this time: 12 in 1966, 40 in 1967, 45 in 1968, 36 in 1969, 34 in 1970 and 4 in 1971.
The charge of metal dipoles was released by rockets and this material had later been observed on radar screens. It was the base of derivation of winds strength in the stratosphere and winds directions in the same atmospheric layer. After experiments that had been conducted in the years 1965–1966, during "The Year of the Quiet Sun", a cyclic pattern of variation in case of directions of these atmospheric flows was concluded.
Meteor-2
The one stage "Meteor-2K" was the most advanced version of the Meteor rocket. On 7 October 1970, the flight took place and reached the altitude of 90 kilometers. This rocket had been used as sounding of the ionosphere, reaching the level of boundary between D and E layers. 10 more flights of this version were realized, when the measurements of temperature were made. The length of rocket frame is 4.5 meters and some are more longer than an English rocket, Petrel (in service since 1968). The "Meteor-2" had not been produced in serial way. The cost of this rocket prototype was eight times higher than for the copy of "Meteor-1". The weight of useful charge, in form of "RAMZES" recovery probe, is 10 kg.
Meteor-3
A two-stage rocket called "Meteor-3" was a developed version of "Meteor-1". The range of flight was increased and the rocket gained possibility of launching of few charges of dipoles. It can reach at ceiling altitudes between 67 and 74 kilometers. An idea of version "S" project had been considered, although never realized. This model could be launch from airplane frame, about 5 kilometers above the surface.
Meteor-4
"Meteor-4" rocket has ten times more thrust than "Meteor-2". This version could reach above 100 km. According to design, this rocket is longer than 5 meters and had the initial total mass of 407 kg with useful weight of 10 kg. 175 seconds into the flight, it would reach at the altitude of 120 kilometers.
Launch Log
External links
https://web.archive.org/web/20060629202124/http://astronautix.com/lvs/meteor.htm
https://web.archive.org/web/20070927120852/http://www.rocketservices.co.uk/spacelists/sounding_rockets/decades/1965-1969.htm
https://web.archive.org/web/20070927120838/http://www.rocketservices.co.uk/spacelists/sounding_rockets/decades/1970-1974.htm
Sounding rockets of Poland
Meteorological instrumentation and equipment
Science and technology in Poland | Meteor (rocket) | Technology,Engineering | 1,115 |
1,356,552 | https://en.wikipedia.org/wiki/Black-Body%20Theory%20and%20the%20Quantum%20Discontinuity%2C%201894%E2%80%931912 | Black-Body Theory and the Quantum Discontinuity, 1894–1912 (1978; second edition 1987) is a book by the philosopher Thomas Kuhn, in which the author surveys the development of quantum mechanics. The second edition has a new afterword.
Summary
Kuhn surveys the development of quantum mechanics by Max Planck at the end of the 19th century. He argues that Planck misread his own earlier work.
Reception
Alexander Bird describes Kuhn's book as "masterly", writing that it "differs from traditional history of science less in the kind of explanation offered and more in the vast erudition and scholarly attention to detail displayed."
According to philosopher Tim Maudlin, Planck and the Black Body Discontinuity (sic) "is a mixed bag: some good historiography and some poor analysis."
References
1978 non-fiction books
American non-fiction books
Books by Thomas Kuhn
English-language non-fiction books
Oxford University Press books
Philosophy of science books
Physics books | Black-Body Theory and the Quantum Discontinuity, 1894–1912 | Physics | 203 |
52,921,789 | https://en.wikipedia.org/wiki/Land%20consumption | Land consumption as part of human resource consumption is the conversion of land with healthy soil and intact habitats into areas for industrial agriculture, traffic (road building) and especially urban human settlements. More formally, the EEA has identified three land consuming activities:
The expansion of built-up area which can be directly measured;
the absolute extent of land that is subject to exploitation by agriculture, forestry or other economic activities; and
the over-intensive exploitation of land that is used for agriculture and forestry.
In all of those respects, land consumption is equivalent to typical land use in industrialized regions and civilizations.
Since often aforementioned conversion activities are virtually irreversible, the term land loss is also used. From 1990 to 2000, of open space were consumed in the U.S. In Germany, land is being consumed at a rate of more than every day (~ per 10 years). In European Union, land take is estimated approximately about to 1.2 million hectares in 21 EU countries over the period 1990–2006.
Land loss can also happen due to natural factors, like erosion or desertification - nevertheless most of those can also eventually be tracked back to human activities. Another slightly different interpretation of the term is the forced displacement or compulsory acquisition of a native people or settlers from their original land due to land grabbing, etc. Again, in most cases, this will be due to economic reasons like search for profitable investment and commodification of natural resources.
Reducing global land loss, which progresses at an alarming rate, is vital since the land footprint, the area required both domestically and abroad to produce the goods and services consumed by a country or region, can be much larger than the land actually used or even available in the country itself.
While land prices have surged in the first few years of the 21st century, land consumption economy still lacks environmental full-cost accounting to add the long-term costs of environmental degradation.
Consequences of land consumption
The major effects of land conversion for economic growth are:
Land degradation
Habitat loss – built-up areas support only particularly adapted species
Soil degradation – loss or contamination of top soil by civilization waste and general pollution
Soil compaction – buildings, heavy machinery and vehicle traffic compact the soil to a degree that macrobiotic soil life is eradicated
Impervious surfaces – asphalt and concrete seal off the soil from the atmosphere and disrupt natural water and biogeochemical cycles
See also
Land reclamation
Land rehabilitation
Land restoration
Land use
References
Land use
Ecology
Environmental issues with soil
Human impact on the environment | Land consumption | Biology,Environmental_science | 504 |
64,625,567 | https://en.wikipedia.org/wiki/Sunspot%20drawing | Sunspot drawing or sunspot sketching is the act of drawing sunspots. Sunspots are darker spots on the Sun's photosphere. Their prediction is very important for radio communication because they are strongly associated with solar activity, which can seriously damage radio equipment.
History
Sunspots were probably first drawn by an English monk John of Worcester on 8 December 1128. There are records of observing sunspots from 28 BC, but that is the first known drawing of sunspots, almost 500 years before the telescope. His drawing seems to come around solar maximum. Five days later, the Korean astronomer saw the northern lights above his country, so this is also the first prediction of coronal mass ejection.
In 1612, Galileo Galilei was writing letters on sunspots to Mark Welser. They were published in 1613. In his telescope, he saw some darker spots on Sun's surface. It seems like he was observing the Sun and drawing sunspots without any filter, which is very hard. He said, "The spots seen at sunset are observed to change the place from one evening to the next, descending from the part of the sun then uppermost, and the morning spots ascend from the part then below ...". From there it seems that he observed the Sun at sunset, but not at sunrise because of the high horizon of Apennines. It is also possible, that he was referring to Scheiner's observation, where he first saw that the Sun is rotating. He complained that he couldn't observe the Sun every morning and evening because of low clouds and so he couldn't see their motion with confidence. He Probably never observed them in the middle of the day. In the same year, his student Benedetto Castelli invented a new method for observing and drawing sunspots, the projection method. Probably, he was never looking at the Sun directly through the telescope.
The Mount Wilson observatory started drawing sunspots by hand in 1917. This tradition continues still today. The early drawers did not draw their shapes and positions very accurately because they wanted just to mark where the sunspots were on the magnetic data. However, in modern times, the drawers became very accurate and sunspot drawing became art; sometimes they needed many hours to complete work. On the white acid-free paper, they draw a circle with solar coordinates and draw and mark sunspots.
Today
With a pinhole and a screen one can produce an image of the Sun. But for better viewings of the sunspots one needs a telescope with 8 inches of diameter or more. There are two ways of drawing sunspots: projection and direct viewing.
Projection on the screen
The easiest way to draw sunspots is to project the image of the Sun to the screen. The further the screen, the bigger the image, but also less bright, so one has to find the perfect proportion. For 10 inch telescope, the optimal distance of the screen from the eyepiece is 1–1.5 meter.
When the Sun is projected, there are two ways for drawing sunspots: you can project Sun on the screen, look at it and draw sunspots on the table, but you can also project the Sun on the drawing paper, just mark the position and draw the shape.
Direct viewing
One less accurate way to do this is to buy the special filter for blocking the light from the Sun. One can look directly in the telescope in that case and draw the sunspots whilst looking at them.
References
External links
Daily image of the Sun and number of the sunspots
Daily illustration of the Sun at Mount Wilson observatory
Technical drawing | Sunspot drawing | Engineering | 750 |
492,224 | https://en.wikipedia.org/wiki/Diviner | Diviner, also referred to as the Diviner Lunar Radiometer Experiment (DLRE), is an infrared radiometer aboard NASA's Lunar Reconnaissance Orbiter, part of the Lunar Precursor Robotic Program which is studying the Moon. It has been used to create temperature maps of the Moon's surface, as well as detect ice deposits and surface composition.
The instrument has measured temperatures of in a crater at the northern pole and in craters at the southern pole. On 9 October 2009, the Diviner team announced the detection of a hot spot on the Moon at the location of the LCROSS spacecraft impact site.
References
External links
Diviner Lunar Radiometer Experiment at UCLA
Lunar Reconnaissance Orbiter
Spacecraft instruments
Radiometry | Diviner | Engineering | 143 |
10,010,405 | https://en.wikipedia.org/wiki/Lyon%27s%20Whelp | Lyon's Whelp or Lion's Whelp is the name of a historical British ship, it is also found in the Bible in Genesis 49:9 “Judah is a lion’s whelp." Popular today, the name was given to a series of 16th-century naval ships, then in the 17th century to a fleet of ten full rigged pinnaces commissioned by the first Duke of Buckingham.
Introduction
The 10 Lion's Whelps built by the 1st Duke of Buckingham in 1628 are exemplars of the 'war' pinnace, a war ship that was built for several European navies for more than two centuries (c.1550-c.1750). The Whelps had sweeps (propelling oars) as well as sails (G R Balleine, All for the King, The Life Story of Sir George Carteret, Societe Jersiase, 1976, p10). England, the Netherlands, Sweden and Poland deployed the war pinnace on a regular basis. The largest war pinnaces, also known as frigates, approximated England's fifth rate and sixth rate small warships. A few war pinnaces were built to fourth-rate hull dimensions. However, these war pinnaces carried fewer cannon and had smaller crews than English fourth, fifth, and sixth rates. Fast and maneuverable when compared to a typical ship of the line, when they were under the command of an experienced captain with a crew that retained discipline during battle, many war pinnaces compiled impressive fighting and espionage records.
Ten ships of the name Lyon's Whelp were built in 1628 by George Villiers, 1st Duke of Buckingham, and each was constructed to the same design. Although masted and armed from the stores of the Royal Navy, the fleet was paid for by the Duke. The entire fleet of ten Lion's Whelps cost Buckingham about £7,000 and for several years, they were his private fleet. With the exception of the Earl of Pembroke, the Duke of Buckingham was the wealthiest nobleman in England at this time. This shipbuilding program indicates that the Duke of Buckingham could access very significant funds. The Duke spent £7000 in 1628 to build his fleet which in the first quarter of 2011 would be worth £624,120.00.
Under the Duke's command, the Lion's Whelps were privateers dedicated to increasing his considerable personal fortune. The fleet of ten Lions Whelps was not taken over by the Navy until 1632, after Buckingham's assassination in 1628, and compensation of at least £4000 was paid to his estate.
The Earl of Nottingham
Lyon's Whelp was the name given to several British naval ships dating back to the 16th century, including at least two that were not financed or built by the Duke of Buckingham. The immediate predecessor to Buckingham's fleet of 10 Lion's Whelps was a war ship named Lion's Whelp that was owned by Charles Howard, 1st Earl of Nottingham, who was the Lord High Admiral of England (1585–1619) and who was succeeded by the Duke of Buckingham.
This Lion's Whelp was loaned to Sir Walter Raleigh and joined the English fleet for the combined Anglo-Dutch attack and expected capture of Cadiz in 1596. Robert Devereux, 2nd Earl of Essex and Sir Walter Raleigh were among the commanders of landing forces while Sir Charles Howard as admiral led the fleet. Victory was swift because the Spanish fleet had been set afire in order not be captured and their land army was badly organized. The Dutch and English sacked and pillaged Cadiz all the while respecting its citizens much to the astonishment of the Spanish. This Lion's Whelp was sold to the state in 1602, and then repaired at Chatham by the ambitious young shipwright Phineas Pett (see below). The Duke of Buckingham received this Lion's Whelp as a gift from King James VI in 1625, shortly before the King died. Ratification of the transfer of ownership occurred under King Charles.
Warrants, contracts, and shipbuilders
Several years ago, John Wassell worked with the Public Record Office in London and England's Calendars of State Papers to research the ten Lion's Whelps built by the Duke of Buckingham in 1628. His web page presents the most important information obtained - original period documents from the archive "State Papers, Domestic". Each Whelp had one gun deck, two masts with a rig that included square sails and lateen. There are only a few contemporary drawings and paintings of English war pinnaces or frigates of the Jacobean era. Details of hull design, armament and rigging are usually inferred using prints and hull designs of warships in the Dutch Navy.
The Duke of Buckingham's project to build 10 Lion's Whelps began with his warrant to two well-placed friends. Captain Sir John Penington and Phineas Pett ensured that the ablest shipwrights of the region would be available for the building of this fleet. Their basic design was a warship of 125 tons with both sails and oars ('sweeps'). Ship construction would be done on the banks of the River Thames, particularly at Ipswich and Shorum. The Lord Admiral was to oversee the "preparation and setting out" for 10 pinnaces of 120 tons each. (Each Lion's Whelp was built to 186 tons.. see below.) Each ship was to have a tender, and adequate supplies of oars, cable, anchors, sails, canvas and 'all other tackling and rigging to be furnished from his 'Majesties Stores', likewise for ordnance and ammunition. "Their Lordships well approving of the said motion did think fit and order the same accordingly." The motive for building these ten ships was the 'enterprise of La Rochelle'. These ten ships would be added to the English fleet that would undertake to relieve the siege of the French Huguenot (Protestant) center of power at La Rochelle imposed by King Louis XIII. Considerable resources must have been available because Phinaeus Pett left this employment at the end of July, which indicates that the ten ships had been completed and launched by that time (~6 months) or shortly thereafter. Thereupon the Duke's fleet set sail for Portsmouth and assignments with the Royal Navy.>ref group=Note>The group that met at Whitehall on 27 February 1627 was impressive. The heart of England's political and military power was present: Lord Keeper (of the privy seal)- Lord Treasurer - Lord President (of the council) - Lord Admiral - Lord Steward - Earl of Suffolk - Earl of Dorset - Earl of Exeter - Earl of Morton - Earl of Kelley - Viscount Wimbledon - Viscount Grandison - Mr. Treasurer – Master of the Ward(robe) - Mr. Chanc(ellor) of the Exchequer - Mr Chanc. of the Duchy (of Lancaster).
Although there are no surviving remains of any of the ten Lion's Whelps built by the Duke of Buckingham, it is possible to obtain a portrait of these ships. Dutch marine painters of the period often included detailed examples of Dutch, English and Spanish ships in their paintings. A small oil-on-copper painting by Abraham de Verwer c.1625, that is now in the England's National Maritime Museum, shows Dutch and English war pinnaces saluting each other outside a harbour. The English ship is a good fit to the reconstructed profile for a Buckingham Lion's Whelp as a three-masted war pinnace with a single gun deck that had eight broadside cannon ports. There is a grating or 'flying deck' over the waist, and Royal Arms decorated the stern. There is another and similar painting of an English single-deck war pinnace in the National Maritime Museum.
The Anglo-French War
At least one of Buckingham's ten Lion's Whelps saw service with the British Fleet in England's attempt to relieve the Huguenot citadel of La Rochelle. English action in the Anglo-French War began with a siege of the fortress of Saint-Martin-de-Re in 1627. The English fleet was not able to lay siege to La Rochelle until several months later.
Historians are indebted to Jacques Callot who published a series of prints illustrating the English landing on the Isle de Re at the beach of Sablanceau, the Siege of Saint Martin-de-Re and the Siege of La Rochelle. Callot's technical innovations enhanced the detail in his prints. In his portrayal of the English fleet, it is possible to differentiate galleons, carracks, pinnaces and perhaps shallops because each ship type had the same minute iconic image. Perhaps one of the pinnaces in these prints is Buckingham's sixth Lion's Whelp.
The besotted King James I assigned a central role to his favorite courtier with the expedition to relieve the Huguenot stronghold of La Rochelle. England hoped that a success would bring the French Protestants into an alliance against Catholic Spain and provide a demonstration of English naval power that would leave King Louis XIII hesitant and fearful. English King James I had made George Villiers, Lord Admiral of the Royal Navy in 1619. As an important commander during the Siege of Saint-Martin-de-Ré (1627) and the attempt to relieve La Rochelle, the Duke of Buckingham revealed a serious lack of understanding and expertise when faced with both army and naval strategic challenges.
The siege of Saint-Martin-de-Ré was the first action in this attempt to take La Rochelle and it began when Buckingham's fleet landed troops on the beach at Sablanceau. Apparently Buckingham insisted on an orderly, slow and methodical organization of his army on the exposed beach, even as French troops and cavalry made repeated lightning attacks, emerging from the protection of the sand dunes. About 100 English casualties on the beach were unnecessary. Later, it was revealed that Buckingham's preparations for the siege of Saint Martin included ladders that proved too short to reach the top of Saint-Martin-de-Re's walls.
English strategy correctly viewed the fortress of Saint-Martin-de-Re as a serious impediment to an assault on La Rochelle. With 80 ships and 7,000 men, Buckingham failed to take the fortress city. After three months and a final failed assault on 27 October 1627, he ended the siege and left for England from Loix with a demoralized, disease ridden force of 2,000 men, the survivors of his original army of 7,000 men.
A Lion's Whelp to Massachusetts
In 1629 a Lion's Whelp sailed with four other ships from Gravesend on 25 April 1629 for the Massachusetts Bay Colony. Arrived and greeted by Governor John Endecott on 30 June 1629. All ships were armed merchantmen. Eight cannon were listed for this Lion's Whelp which is the number carried by the Duke of Buckingham's Lion's Whelps and most armed pinnaces as well. Is this ship Buckingham's second Lion's Whelp, diverted for a cross Atlantic run with settlers and provisions to the Massachusetts Bay Colony? A careful scrutiny of the record is not supportive of this conclusion. This Lion's Whelp is tentatively identified as the 120-ton ship that brought William Dodge, along with the Sprague family and others to Salem, Massachusetts in 1629. The Lyon's Whelp left Gravesend 24/25 April 1629 and arrived in Salem mid-July 1629, under Master John Gibbs (or Gibbon). It was one of six ships in a small fleet; the others including Talbot, George Bonaventure, Lyon, and a ship called Mayflower (though not the Mayflower of the Pilgrims). This Lion's Whelp and her sister ships the Talbot and the George carried goods and new settlers to Naumkaeg, the Indian name for the territory settled by England's Massachusetts Bay Company at Salem.
Appendix: 10 Lion's Whelps
Final costings for each Lion's Whelp are believed to have been in excess of the contracted rate, thereby raising the possibility that shipwrights deliberately built ships larger than agreed upon in order to inflate the final invoice. The worse example of this was Peter Pett and the sixth Whelp. The Duke wanted each Whelp to weigh 120 tonnes, and cost £139.5.
After the Duke was assassinated in 1632, his fleet of ten Lion Whelps was taken into the Royal Navy and the estate reimbursed £4,500 according to Captain Penington who had supervised their construction. Had the fleet been sold to England, as the Earl of Nottingham had done with his Lion's Whelp in 1602, very likely much more money would have accrued to the Buckingham estate.
Buckingham's first Lion's Whelp was built by William Castell of Southwark St Saviour in 1628. After the Duke was assassinated in 1632, she was taken into the Royal Navy and then converted into a chain ship for the Chatham "barricado" c. 1641. She was sent to Harwich as a careening hulk in August 1650, and then drops out of the historical record. Lion's Whelp may be the hulk at Harwich that was ordered to be sold in October 1651.
The second Lion's Whelp was also built by William Castell of St. Savior's in Southwark. She was converted into a chain ship for the Chatham 'barricado' c.1641, then was ordered to be sold in August, 1650 together with the Defiance and Merhonour as having become too decayed, even to be a careening hulk at Harwich.
The third Lion's Whelp was built by John Dearsley of Ipswich at Wapping. She was listed as unfit for service in Batten's survey of 1647 and 'cast' before February, 1643.
The fourth Lion's Whelp was built by Christopher Malim of Redriff. She was used for experimental constructions in the Project Dutchman, c.1633. These works in the hold were ordered for removal in March 1643 because they were of no use in a man-o-war. Details of the experimental constructions are lacking, although Warrell's research points to Cornelius Drebbel as having executed the removal order. The fourth Lion's Whelp struck a rock in St. Aubrey's Bay, Jersey on 4 August 1636 and sank without any loss of life.
The fifth Lion's Whelp was built by Peter Marsh of Wapping and spent most of her life in service in Ireland. She foundered in the North Sea on 28 June 1637 and sank with the loss of 17 men. Cause of this tragedy was placed with the shipyard who built her of 'mean, sappy timbers'.
The sixth Lion's Whelp was built by Peter Pett of Ratcliffe. Peter Pett (1610-?1672) was an English Master Shipwright, the second Resident Commissioner of the Chatham Dockyard. Phinaes Pett was viewed as the greatest shipbuilder of his time, indeed perhaps the finest to have ever lived and worked in England. The reputation of the Pett dynasty ensured that the sixth Lion's Whelp was designed and constructed to the highest standards. Her captain was John Pett (1601/2 – 1628), the eldest son of Phineas Pett who died when the ship went down off the coast of Brittany when returning from the La Rochelle expedition in 1628.
The seventh Lion's Whelp was built by Matthew Graves of Limehouse, She and the famous ship-of-the-line' Mary Rose got into a dispute with a Dutch warship from Enkhuisen over a Dutch privateer captured off the Suffolk coast. Negligence in the powder store led to a fierce explosion that destroyed the seventh Lion's Whelp amidst action involving several ships from both countries. There is speculation that Captain Cooper became severely disoriented immediately after the loss of the ship, and thereafter was mentally incompetent.
The eighth Lion's Whelp was built in the yard of John Graves of Limehouse. In 1633 she was given to George Carteret as his first independent command. His first task was to attend the Vauntguard which Penington commanded (Balleine, op. cit, p10). Later, in 1644 she was used to transport gold to the Scottish parliament. The Eighth is another pinnace in the Duke's fleet that went 'rotten'. In July 1645, she was judged too decayed to repair and ordered to be laid up on the Woolwich shore.
The ninth Lion's Whelp was also built by John Graves of Limehouse and spent her active years in the Irish service, where she was mainly used to put down piracy in Dublin Bay, and sometimes to ferry important visitors to Ireland. Her captain was Dawtrey Cooper in 1632/33, who had been the captain of the seventh Lion's Whelp when a seaman's negligence caused a fearful explosion and loss of life. During the ninth Lion's Whelp service at Ireland, there were continual disputes and near mutinies. She came to an end as a wreck in the River Clyde with the pinnace Confidence while taking supplies from Ireland to Dumbarton Castle (which is on the Clyde near Glasgow) in April, 1640. There is an incorrect record that the eighth and ninth Lion's Whelps were lost in a storm in 1628 that had wrecked the sixth. After a brief period of out of contact, the eighth and ninth returned to Portsmouth.
The tenth Lion's Whelp was built by Robert Tranckmore of Shoreham, went over to the Royalists after the fall of Bristol in 1643, then was recaptured by Parliament's forces in 1645. She was at Helvoetsluys with the Earl of Warwick's fleet in 1648, then was fitted out as a fireship for Blake's pursuit of Prince Rupert to Lisbon in 1650. Later the tenth Lion's Whelp was used for convoy work and communications during the First Anglo-Dutch War. The last historical mention of the tenth Lion's Whelp is on 19 October 1654 when she was sold to Jacob Blackpath for £410.
With sale of the tenth, this fleet of Lion's Whelps passes from recorded history. Their fragmentary historical record has provided additional information about the building of small war ships in the 17th century, and activities of the Royal Navy in the Anglo-French War.
Footnotes
External links
Lion's Whelp, 1628 three-masted pinnace, Virginia Historical Society, retrieved 12 December 2010.
16th century large English pinnace - early print. Lacking identity and provenance as depicted on Dr. J.P. Sommerville's page about Elizabeth I: Exploration and Foreign Policy (University of Wisconsin), n.d. Retrieved 18 September 2008.
References
Mystery of the Lion's Whelps, by Bennett Blumenerg, 23 March 2011.
Lion's Whelp 1628 three-masted pinnace , by New Zealand National Maritime Museum, nd. Retrieved 12 December 2010.
Hooker, Hourcre, Hourque, Hoeker Retrieved on Sept.1, 2008.
History of Ten Lions Whelps, by John Wassells, nd. Retrieved 11 February 2011.
The Lion's Whelps – Introduction, History, Construction, What Did They Look Like? by James Wassell, 23 February 2003. Retrieved 11 February 2011.
Mathew Baker and the Art of the Shipwright (in German). Baker was royal ship builder under Elizabeth I. His Fragments of Ancient Shipbuilding (1586) is considered a ground breaking work and invaluable for the study of 16th century shipbuilding. Sept.15, 2005.
When Galleons Ruled the Waves, by Ken Johnson, 30 July 2009. Retrieved 13 March 2011.
1620s conflicts
1627 in France
17th century in France
Anglo-French wars
History of the Royal Navy
Naval architecture
Pinnaces
Ships of the Royal Navy
Sieges involving France
Thirty Years' War
George Villiers, 1st Duke of Buckingham | Lyon's Whelp | Engineering | 4,192 |
39,338,812 | https://en.wikipedia.org/wiki/Tra%20%28gene%29 | Female-specific protein transformer is a protein that in Drosophila melanogaster is encoded by the tra gene. Unlike the related tra2 protein, it is only produced in females.
The transformer protein controls female somatic sexual differentiation. The protein contains an RNA recognition motif. It controls the alternative splicing of the fly sex determination gene doublesex.
References
Drosophila melanogaster genes
Insect proteins | Tra (gene) | Chemistry | 89 |
28,105,864 | https://en.wikipedia.org/wiki/Biogeography%20of%20Deep-Water%20Chemosynthetic%20Ecosystems | The Biogeography of Deep-Water Chemosynthetic Ecosystems is a field project of the Census of Marine Life programme (CoML). The main aim of ChEss is to determine the biogeography of deep-water chemosynthetic ecosystems at a global scale and to understand the processes driving these ecosystems. ChEss addresses the main questions of CoML on diversity, abundance and distribution of marine species, focusing on deep-water reducing environments such as hydrothermal vents, cold seeps, whale falls, sunken wood and areas of low oxygen that intersect with continental margins and seamounts.
Background
Deep-sea hydrothermal vents and their associated fauna were first discovered along the Galapagos Rift in the eastern Pacific in 1977. Vents are now known to occur along all active mid ocean ridges and back-arc spreading centres, from fast to ultra-slow spreading ridges. The interest in chemosynthetic environments was strengthened by the discovery of chemosynthetic-based fauna at cold seeps along the base of the Florida Escarpment in 1983. Cold seeps occur along active and passive continental margins. More recently, the study of chemosynthetic fauna has extended to the communities that develop in other reducing habitats such as whale falls, sunken wood and areas of oxygen minima when they intersect with the margin or seamounts.
Since the first discovery of hydrothermal vents, more than 600 species have been described from vents and seeps. This is equivalent of 1 new description every 2 weeks(!). As biologists, geochemists, and physicists combine research efforts in these systems, new species will certainly be discovered. Moreover, because of the extreme conditions of the vent and seep habitat, certain species may have specific physiological adaptations with interesting results for the biochemical and medical industry.
These globally distributed, ephemeral and insular habitats that support endemic faunas offer natural laboratories for studies on dispersal, isolation and evolution. Here, hydrographic and topographic controls on biodiversity and biogeography might be much more readily resolved than in systems where climate and human activity obscure their role. In addition, hydrothermal vents have been suggested to be the habitat of the origin of life. These hypotheses are being used by ChEss researchers in collaboration with NASA to develop programmes to search for life in planets or moons of the outer space.
Objectives of ChEss
Only a small fraction of the global ridge system (~65000 km) and of the vast continental margin regions have been explored and their communities described. It is the aim of ChEss to improve the knowledge on the diversity, abundance and distribution of species from vents, seeps and other reducing habitats at a global scale, understanding the abiotic and biotic processes that shape and maintain these ecosystems and their biogeography.
Main ChEss Science Questions
I. What are the species' relationships between different habitats: vents, seeps, whale falls, sunken wood and OMZs?
II. What is the role of deep-water circulation and geographical barriers in gene flow and biogeography?
III. What are the factors driving patterns of biodiversity in these habitats?
Objective 1. To create a centralised database
To create a centralised database, ChEssBase, of deep-water vent, cold seep, whalefall and OMZ species. ChEssBase is a web-based database that incorporates archived and newly collected biological material. The database is geo- and bio-referenced. ChEssBase is available online and has been integrated with OBIS.
Objective 2. To develop a long-term field programme
To develop a long-term field programme to locate potential vent and seep sites and continue research on whalefalls and OMZ sites. The field programme aims to explain the main gaps in our knowledge of the diversity, abundance and distribution of chemosynthetic species globally. A limited number of target areas have been selected where specific scientific questions relevant to biogeographical issues will be answered.
The target areas have been grouped into two categories. Category I, combined areas: Area A: Equatorial Atlantic Belt region; Area B: the SE Pacific region; Area C: NZ region; Area D: the Arctic and Antarctic regions, within the International Polar Year. Category II, specific areas: 1 – The ice-covered Gakkel Ridge, 2 – the (ultra)-slow ridges of the Norwegian-Greenland Sea, 3 – the northern MAR between the Iceland and Azores hot-spots; 4 – the Brazilian continental margin, 5 – the East Scotia Ridge and Bransfield Strait, 6 – the SW Indian Ridge, 7 – the Central Indian Ridge.
During the field programme, ChEss will promote the development and refinement of deep-towed, remotely operated (ROV) and autonomous underwater (AUV) vehicle technologies to locate, map and sample new chemosynthetic systems. Using optical, chemical and acoustic techniques, ChEss researchers hope to gain a better understanding of not only biogeographical patterns, but to determine the processes driving these ecosystems.
During the field programme, ChEss will promote the development and refinement of deep-towed, remotely operated (ROV) and autonomous underwater (AUV) vehicle technologies to locate, map and sample new chemosynthetic systems. Using optical, chemical and acoustic techniques, ChEss researchers hope to gain a better understanding of not only biogeographical patterns, but to determine the processes driving these ecosystems.
Objective 3: Outreach and Education
ChEss has multi-lingual education pages related to vents, seeps and whalefalls. There is a dedicated page for key outreach initiatives such as live cruise diaries, open days, schools activities etc.
ChEss has joined forces with the other deep-sea CoML projects and this has resulted in the creation of the DEep-Sea Education and Outreach group (DESEO) that has produced a book "Deeper than Light" published in 5 languages.
References
External links
ChEss Website
title Third SCOR Meeting on Coordination of International Marine Research Projects
Literatur online. Buchdetails
https://web.archive.org/web/20090218015144/http://tos.org/oceanography/issues/issue_archive/20_1.html
Recent ChEss-Related Publications
Biogeography
Biological censuses
Chemical oceanography
Marine biology
Research projects
Projects established in 2000 | Biogeography of Deep-Water Chemosynthetic Ecosystems | Chemistry,Biology | 1,278 |
4,260,103 | https://en.wikipedia.org/wiki/Hazard%20%28logic%29 | In digital logic, a hazard is an undesirable effect caused by either a deficiency in the system or external influences in both synchronous and asynchronous circuits. Logic hazards are manifestations of a problem in which changes in the input variables do not change the output correctly due to some form of delay caused by logic elements (NOT, AND, OR gates, etc.) This results in the logic not performing its function properly. The three different most common kinds of hazards are usually referred to as static, dynamic and function hazards.
Hazards are a temporary problem, as the logic circuit will eventually settle to the desired function. Therefore, in synchronous designs, it is standard practice to register the output of a circuit before it is being used in a different clock domain or routed out of the system, so that hazards do not cause any problems. If that is not the case, however, it is imperative that hazards be eliminated as they can have an effect on other connected systems.
Static hazards
A static hazard is a change of a signal state twice in a row when the signal is expected to stay constant. When one input signal changes, the output changes momentarily before stabilizing to the correct value. There are two types of static hazards:
Static-1 Hazard: the output is currently 1 and after the inputs change, the output momentarily changes to 0,1 before settling on 1
Static-0 Hazard: the output is currently 0 and after the inputs change, the output momentarily changes to 1,0 before settling on 0
In properly formed two-level AND-OR logic based on a Sum Of Products expression, there will be no static-0 hazards (but may still have static-1 hazards). Conversely, there will be no static-1 hazards in an OR-AND implementation of a Product Of Sums expression (but may still have static-0 hazards).
The most commonly used method to eliminate static hazards is to add redundant logic (consensus terms in the logic expression).
Example of a static hazard
Consider an imperfect circuit that suffers from a delay in the physical logic elements i.e. AND gates etc.
The simple circuit performs the function noting:
From a look at the starting diagram it is clear that if no delays were to occur, then the circuit would function normally. However, no two gates are ever manufactured exactly the same. Due to this imperfection, the delay for the first AND gate will be slightly different than its counterpart. Thus an error occurs when the input changes from 111 to 011. i.e. when A changes state.
Now we know roughly how the hazard is occurring, for a clearer picture and the solution on how to solve this problem, we would look to the Karnaugh map.
A theorem proved by Huffman tells us that adding a redundant loop 'BC' will eliminate the hazard.
The amended function is:
Now we can see that even with imperfect logic elements, our example will not show signs of hazards when A changes state. This theory can be applied to any logic system. Computer programs deal with most of this work now, but for simple examples it is quicker to do the debugging by hand. When there are many input variables (say 6 or more) it will become quite difficult to 'see' the errors on a Karnaugh map.
Dynamic hazards
A dynamic hazard are a series of changes of a signal state that happen several times in a row when the signal is expected to change state only once. A dynamic hazard is the possibility of an output changing more than once as a result of a single input change.
Dynamic hazards often occur in larger logic circuits where there are different routes to the output (from the input). If each route has a different delay, then it quickly becomes clear that there is the potential for changing output values that differ from the required / expected output.
E.g. A logic circuit is meant to change output state from 1 to 0, but instead changes from 1 to 0 then 1 and finally rests at the correct value 0. This is a dynamic hazard.
As a rule, dynamic hazards are more complex to resolve, but note that if all static hazards have been eliminated from a circuit, then dynamic hazards cannot occur.
Functional hazards
In contrast to static and dynamic hazards, functional hazards are ones caused by a change applied to more than one input. There is no specific logical solution to eliminate them. One really reliable method is preventing inputs from changing simultaneously, which is not applicable in some cases. So, circuits should be carefully designed to have equal delays in each path.
Others
Combinational logic hazards
In combinational logic is a hazard that depend on the distribution of signal propagation delays in the logic circuits and overall design of a logic circuit function implemented.
Combinational functional hazards
In combinational logic are hazards that can be detected and suppressed at a higher level of programming, by studying and modifying the output logic function.
Sequential hazards Is a kind of undesirable signal changes found in looped systems.
See also
Don't care
Glitch
Hazard (computer architecture)
Race condition
Floating body effect, a probably cause for hazard silicon on Insulator-devices
References
http://www.ee.surrey.ac.uk/Projects/Labview/Sequential/Course/02-Hazards/hazards.htm#FunctionHazards
Digital electronics | Hazard (logic) | Engineering | 1,076 |
26,012,456 | https://en.wikipedia.org/wiki/SECORE | SECORE (SExual COral REproduction) is an international non-profit organization focused on coral reef conservation. The group has over sixty supporters in North America, Europe and Japan, and comprises public aquariums, institutes, and universities. Founded in 2001 at the Rotterdam Zoo in the Netherlands, the organization has been developing methods of captive coral reproduction and preservation, citing studies that have predicted coral reefs could be extinct within decades due to climate change.
Background
Based on the coral reproduction research of Dirk Petersen at the Rotterdam Zoo (The Netherlands), SECORE was born in 2002. Petersen's findings led to innovative techniques on the use sexual coral reproduction for coral reef conservation. Established by the aquarium community and coral conservation scientists, SECORE initially focused on ex situ conservation and later as well on reef restoration (in situ conservation).
In 2004, Mike Brittsan, M.Sc., of the Columbus Zoo & Aquarium joined SECORE to take over the leading role in the USA. Over the years, both institutions, the Rotterdam Zoo and the Columbus Zoo & Aquarium – in collaboration with other organisations – started a very successful workshop program not only to train experts in the SECORE techniques, but also to bring different institutions together for a common goal – help saving the greatest marine ecosystem on our planet, the coral reef. SECORE supports excellent science in various fields, such as coral restoration, coral population genetics or coral cryopreservation.
Together with its more than 60 supporting partner institutions, SECORE reaches millions of people to spread the word about the dramatic situation of our ocean and what we can do about it. In 2018, they were subject of coverage from VICE News for their work in the coral reefs of Curaçao.
Supporters
Asia
Ochanomizu University
Marine Research Station Layang Layang
Europe
The Deep
National Marine Aquarium
Aquarium La Rochelle
Océanopolis
Aquazoo – Löbbecke Museum in Düsseldorf
Cologne Zoo
Hagenbeck Zoo
Ruhr University Bochum
University of Duisburg-Essen
Wilhelma Stuttgart
Acquario di Genova
Musee Oceanographique
Artis Zoo
Burgers Zoo
Rotterdam Zoo
Wageningen University
Oceanario de Lisboa
Planet Neptune Aquarium
Zoo Aquarium de Madrid
The Maritime Museum and Aquarium in Gothenburg
Skansen-Akvariet
North America
Curaçao Sea Aquarium
Audubon Aquarium of the Americas
Aquarium in Moody Gardens
Berkshire Museum Aquarium
Birch Aquarium
Columbus Zoo and Aquarium
Dallas Aquarium at Fair Park
Discovery World
Downtown Aquarium, Houston
The Florida Aquarium
Georgia Aquarium
Hawaii Institute of Marine Biology
Houston Zoo
Indianapolis Zoo
Minnesota Zoo
National Aquarium in Baltimore
National Aquarium in Washington, D.C.
National Zoological Park (United States)
New England Aquarium
North Carolina Aquarium at Fort Fisher
North Carolina Aquarium at Pine Knoll Shores
Omaha's Henry Doorly Zoo
Pennsylvania State University
Pittsburgh Zoo & PPG Aquarium
Point Defiance Zoo & Aquarium
Seattle Aquarium
Seaworld Orlando
Seaworld Texas
Shedd Aquarium
University of Houston
Virginia Living Museum
Virginia Marine Science Museum
See also
Issues with coral reefs
Iliana Baums
References
External links
SECORE website
SECORE Workshop Curacao 2011
Mary Hagedorn and Mike Henley. Rearing Elkhorn coral at the National Zoo
Acropora palmata larve video, Coralscience.org
Pennisi E. 2007. Reefs in trouble - spawning for a better life. Science 318(5857):1712-1717.
Marine conservation organizations
Coral reefs
International environmental organizations
Organizations established in 2002
2002 establishments in the Netherlands | SECORE | Biology | 683 |
725,067 | https://en.wikipedia.org/wiki/Gemfibrozil | Gemfibrozil, sold under the brand name Lopid among others, is a medication used to treat abnormal blood lipid levels. It is generally less preferred than statins. Use is recommended together with dietary changes and exercise. It is unclear if it changes the risk of heart disease. It is taken by mouth.
Common side effects include headache, dizziness, feeling tired, and intestinal upset. Serious side effects may include angioedema, gallstones, liver problems, and muscle breakdown. Use in pregnancy and breastfeeding is of unclear safety. It belongs to the fibrates group of medications and works by decreasing the breakdown of lipids in fat cells.
Gemfibrozil was patented in 1968, and came into medical use in 1982. It is available as a generic medication. In 2022, it was the 231st most commonly prescribed medication in the United States, with more than 1million prescriptions.
Medical uses
Hyperlipidemia (Type III)
Hypertriglyceridemia (Type IV): Gemfibrozil, though not as effective as niacin (nicotinic acid, a form of Vitamin B3), is better tolerated.
Reduce triglyceride levels
Reduce very low density lipoprotein (VLDL) levels
Modest reduction of low density lipoprotein (LDL) levels
Moderate increase in high density lipoprotein (HDL) levels
Side effects
GI distress
Musculoskeletal pain
Increased incidence of gallstone
Hypokalemia (low blood potassium)
Increased risk of cancer
Contraindications
Gemfibrozil should not be given to these patients:
Hepatic dysfunction
Gemfibrozil should be used with caution in these higher risk categories:
Biliary tract disease
Renal dysfunction
Pregnant women
Obese patients
Drug interactions
Anticoagulants: Gemfibrozil potentiates the action of warfarin and indanedione anticoagulants.
Statin drugs: Concomitant administration of fibrates (including gemfibrozil) with statin drugs increases the risk of muscle cramping, myopathy, and rhabdomyolysis.
Gemfibrozil inhibits the activation of the liver's Cytochrome P450 system and CYP2C8, reducing hepatic metabolism of many drugs, and prolonging their half lives and duration of action.
Drugs metabolized by the Cytochrome P450 system include:
Many antidepressants
Many antipsychotics
Many antiepileptics
Theophylline and other methylxanthine drugs
Several anesthetic agents
Oral contraceptive pills
Statins
Warfarin
Selexipag
Mechanism of actions
The exact mechanism of action of gemfibrozil is unknown; however, several theories exist regarding the very low density lipoprotein (VLDL) effect; it can inhibit lipolysis and decrease subsequent hepatic fatty acid uptake as well as inhibit hepatic secretion of VLDL; together these actions decrease serum VLDL levels and increase HDL-cholesterol; the mechanism behind HDL elevation is currently unknown.
Gemfibrozil increases the activity of extrahepatic lipoprotein lipase (LL), thereby increasing lipoprotein triglyceride lipolysis. It does so by activating peroxisome proliferator-activated receptor alpha (PPARα) 'transcription factor ligand', a receptor that is involved in metabolism of carbohydrates and fats, as well as adipose tissue differentiation. This increase in the synthesis of lipoprotein lipase thereby increases the clearance of triglycerides. Chylomicrons are degraded, VLDLs are converted to LDLs, and LDLs are converted to HDL. This is accompanied by a slight increase in secretion of lipids into the bile and ultimately the intestine. Gemfibrozil also inhibits the synthesis and increases the clearance of apolipoprotein B, a carrier molecule for VLDL.
History
Gemfibrozil was selected from a series of related compounds synthesized in the laboratories of the American company Parke-Davis in the late 1970s. It came from research for compounds that lower plasma lipid levels in humans and in animals.
Environmental data
Gemfibrozil has been detected in biosolids (the solids remaining after sewage treatment) at concentrations up to 2650 ng/g wet weight. This indicates that it survives the wastewater treatment process. It is also detected as environmental persistent micropollutant in aquifers and in groundwaters in karstic areas.
References
Further reading
External links
Wikipedia medicine articles ready to translate
Fibrates
Phenol ethers
Carboxylic acids
CYP2C8 inhibitors
Drugs developed by Pfizer | Gemfibrozil | Chemistry | 998 |
11,069,121 | https://en.wikipedia.org/wiki/Monilinia%20laxa | Monilinia laxa is a plant pathogen that is the causal agent of brown rot of stone fruits.
Disease cycle
Monilinia laxa is an ascomycete fungus that is responsible for the brown rot blossom blight disease that infects many different types of stone fruit trees, such as apricots, cherries and peaches. It can also occasionally affect some pome fruits; for example, apples and pears. The pathogen overwinters on infected plant parts, particularly on infected twigs, branches, old flower parts or mummified fruits. In spring, the pathogen produces asexual conidia on the aforementioned infected plant debris. In addition, apothecia, which are small, open cup, mushroom-like sexual propagative structures of M. laxa that produce ascospores, also develop on the fallen fruits on the ground. Both asexual (conidia) and sexual (ascospores) spore types are spread during the spring via wind and rain in which they infect blossoms and young shoots. Floral tissue is the most susceptible to both spores’ infection when the trees are in full bloom. The infected floral tissues are responsible for the production of the secondary inoculums that further continues the disease cycle during the spring season. If the environmental conditions are very conducive (i.e. warm and wet environments), infection can also occur in non-flowering shoots or leaves. Infection is sometimes not visible until after the fruit begins to ripen and the pit hardens. These ripe fruits are at a high risk of being infected and passing the disease onto other plants during harvest.
Importance
Throughout the entire world, brown rot is arguably the most common reason for crop loss of stone fruits both before and after harvest, especially in regions with warmer temperatures and wet climates.[5] This disease has actually been shown to have a variety of incidence from year to year due to environmental variation. Before the discovery of extremely effective fungicides, when fruit ripened during a period of high rainfall, there were significant losses due to Brown rot blossom blight.[5] After centuries of studying this disease in both Europe and North America, the use of fungicides have more recently become effective. Demethylation inhibitor (DMI) fungicides and Benzimidazole (BZI) fungicides are both examples of common fungicides that have been used to treat brown rot. However, since the beginning of these fungicides, another set of problems arose. After time, brown rot has become resistant to a few fungicides including both DMI and BZI. Luckily, scientists have been able to develop strategies for managing or delaying fungicide resistance to Brown rot blossom blight.[6]
In addition to this, brown rot has been shown to be of serious economic importance even though it has been harder to estimate. Brown rot can cause detrimental losses to stone fruits in very wet seasons during flowering or immediately pre-harvest. Brown rot mostly occurs on maturing fruit close to harvest. Moreover, these losses may occur to fruit after postharvest. For example, post harvest decay of fruits have been approximated to be about 9% loss during transporting and marketing just in the US.
Environment
Monilinia laxa proliferates the most in warm and wet weather. Therefore, it is unsurprising to find that it is most commonly found in California as well as the midwestern and northeastern states. Conversely, the disease has not been found in the southeastern states. Outside of the United States, M. laxa is commonly found in Europe, South Africa, and Chile.
Conidia begin to develop on infected plant debris once the temperature reaches . While infection does not occur below , it does occur once the temperature increases beyond that point. The ideal temperature for M. laxa infection is between . The spores produced by this pathogen can be dispersed by both wind and rain. However, the fungus is also able to proliferate in dry and highly humid conditions. Compared to in cooler conditions, at high humidity ash-gray-brown spore masses can form on the diseased flowers and twig cankers. Typically fruit susceptibility to brown rot increases about two to three weeks prior to harvest.
References
Sclerotiniaceae
Fungal plant pathogens and diseases
Apple tree diseases
Stone fruit tree diseases
Fungi described in 1945
Fungus species | Monilinia laxa | Biology | 894 |
30,756,726 | https://en.wikipedia.org/wiki/Creamed%20coconut | Creamed coconut, also known as coconut butter, is a coconut product made from the unsweetened dehydrated fresh pulp of a mature coconut, ground to a semi-solid white creamy paste. It is sold in the form of a hard white block which can be stored at room temperature. (Coconut butter melts at around 24°C, so in warmer weather it is a liquid paste.) The block is generally packaged in a sealed plastic pouch and some separation of the fat and the coconut flesh can be seen. It may also come in bottles similar to how most nut butters are packaged. In cookery, it is chopped into pieces or grated before it is added to dishes. By adding warm water it can be made into coconut milk or coconut cream substitutes. Adding water to creamed coconut in the ratio 5:2 gives a coconut cream substitute, 5:1 gives a coconut milk substitute.
Creamed coconut, or coconut butter can also be made by placing unsweetened shredded coconut into the bowl of a food processor and processing on high speed for 10 to 15 minutes.
Creamed coconut is added to Indian, South East Asian and Caribbean recipes to enrich curries and sauces. In the west, it is primarily used in confectionery items, desserts, ice cream, and sauces. Creamed coconut should not be confused with the related coconut cream, which is a liquid extracted from coconut pulp but does not include the coconut pulp itself.
Creamed coconut is particularly high in saturated fat (61% of total composition), and provides 684 calories in a reference amount of . Values per 100g:
Water: 2 g
Protein: 5 g
Carbohydrate: 22 g
Fats: 69 g
See also
Coco Lopez
Coconut cream
Coconut milk
Coconut oil
Coconut water
References
Websites
Foods containing coconut
Food ingredients
Drink mixers
Creamy dishes | Creamed coconut | Technology | 381 |
292,877 | https://en.wikipedia.org/wiki/F4%20%28mathematics%29 | {{DISPLAYTITLE:F4 (mathematics)}}
In mathematics, F4 is a Lie group and also its Lie algebra f4. It is one of the five exceptional simple Lie groups. F4 has rank 4 and dimension 52. The compact form is simply connected and its outer automorphism group is the trivial group. Its fundamental representation is 26-dimensional.
The compact real form of F4 is the isometry group of a 16-dimensional Riemannian manifold known as the octonionic projective plane OP2. This can be seen systematically using a construction known as the magic square, due to Hans Freudenthal and Jacques Tits.
There are 3 real forms: a compact one, a split one, and a third one. They are the isometry groups of the three real Albert algebras.
The F4 Lie algebra may be constructed by adding 16 generators transforming as a spinor to the 36-dimensional Lie algebra so(9), in analogy with the construction of E8.
In older books and papers, F4 is sometimes denoted by E4.
Algebra
Dynkin diagram
The Dynkin diagram for F4 is: .
Weyl/Coxeter group
Its Weyl/Coxeter group is the symmetry group of the 24-cell: it is a solvable group of order 1152. It has minimal faithful degree , which is realized by the action on the 24-cell. The group has ID (1152,157478) in the small groups library.
Cartan matrix
F4 lattice
The F4 lattice is a four-dimensional body-centered cubic lattice (i.e. the union of two hypercubic lattices, each lying in the center of the other). They form a ring called the Hurwitz quaternion ring. The 24 Hurwitz quaternions of norm 1 form the vertices of a 24-cell centered at the origin.
Roots of F4
The 48 root vectors of F4 can be found as the vertices of the 24-cell in two dual configurations, representing the vertices of a disphenoidal 288-cell if the edge lengths of the 24-cells are equal:
24-cell vertices:
24 roots by (±1, ±1, 0, 0), permuting coordinate positions
Dual 24-cell vertices:
8 roots by (±1, 0, 0, 0), permuting coordinate positions
16 roots by (±1/2, ±1/2, ±1/2, ±1/2).
Simple roots
One choice of simple roots for F4, , is given by the rows of the following matrix:
The Hasse diagram for the F4 root poset is shown below right.
F4 polynomial invariant
Just as O(n) is the group of automorphisms which keep the quadratic polynomials invariant, F4 is the group of automorphisms of the following set of 3 polynomials in 27 variables. (The first can easily be substituted into other two making 26 variables).
Where x, y, z are real-valued and X, Y, Z are octonion valued. Another way of writing these invariants is as (combinations of) Tr(M), Tr(M2) and Tr(M3) of the hermitian octonion matrix:
The set of polynomials defines a 24-dimensional compact surface.
Representations
The characters of finite dimensional representations of the real and complex Lie algebras and Lie groups are all given by the Weyl character formula. The dimensions of the smallest irreducible representations are :
1, 26, 52, 273, 324, 1053 (twice), 1274, 2652, 4096, 8424, 10829, 12376, 16302, 17901, 19278, 19448, 29172, 34749, 76076, 81081, 100776, 106496, 107406, 119119, 160056 (twice), 184756, 205751, 212992, 226746, 340119, 342056, 379848, 412776, 420147, 627912...
The 52-dimensional representation is the adjoint representation, and the 26-dimensional one is the trace-free part of the action of F4 on the exceptional Albert algebra of dimension 27.
There are two non-isomorphic irreducible representations of dimensions 1053, 160056, 4313088, etc. The fundamental representations are those with dimensions 52, 1274, 273, 26 (corresponding to the four nodes in the Dynkin diagram in the order such that the double arrow points from the second to the third).
Embeddings of the maximal subgroups of F4 up to dimension 273 with associated projection matrix are shown below.
See also
24-cell
Albert algebra
Cayley plane
Dynkin diagram
Fundamental representation
Simple Lie group
References
John Baez, The Octonions, Section 4.2: F4, Bull. Amer. Math. Soc. 39 (2002), 145-205. Online HTML version at http://math.ucr.edu/home/baez/octonions/node15.html.
Algebraic groups
Lie groups
Exceptional Lie algebras | F4 (mathematics) | Mathematics | 1,085 |
2,029,932 | https://en.wikipedia.org/wiki/Courant%E2%80%93Friedrichs%E2%80%93Lewy%20condition | In mathematics, the convergence condition by Courant–Friedrichs–Lewy is a necessary condition for convergence while solving certain partial differential equations (usually hyperbolic PDEs) numerically. It arises in the numerical analysis of explicit time integration schemes, when these are used for the numerical solution. As a consequence, the time step must be less than a certain upper bound, given a fixed spatial increment, in many explicit time-marching computer simulations; otherwise, the simulation produces incorrect or unstable results. The condition is named after Richard Courant, Kurt Friedrichs, and Hans Lewy who described it in their 1928 paper.
Heuristic description
The principle behind the condition is that, for example, if a wave is moving across a discrete spatial grid and we want to compute its amplitude at discrete time steps of equal duration, then this duration must be less than the time for the wave to travel to adjacent grid points. As a corollary, when the grid point separation is reduced, the upper limit for the time step also decreases. In essence, the numerical domain of dependence of any point in space and time (as determined by initial conditions and the parameters of the approximation scheme) must include the analytical domain of dependence (wherein the initial conditions have an effect on the exact value of the solution at that point) to assure that the scheme can access the information required to form the solution.
Statement
To make a reasonably formally precise statement of the condition, it is necessary to define the following quantities:
Spatial coordinate: one of the coordinates of the physical space in which the problem is posed
Spatial dimension of the problem: the number of spatial dimensions, i.e., the number of spatial coordinates of the physical space where the problem is posed. Typical values are , and .
Time: the coordinate, acting as a parameter, which describes the evolution of the system, distinct from the spatial coordinates
The spatial coordinates and the time are discrete-valued independent variables, which are placed at regular distances called the interval length and the time step, respectively. Using these names, the CFL condition relates the length of the time step to a function of the interval lengths of each spatial coordinate and of the maximum speed that information can travel in the physical space.
Operatively, the CFL condition is commonly prescribed for those terms of the finite-difference approximation of general partial differential equations that model the advection phenomenon.
The one-dimensional case
For the one-dimensional case, the continuous-time model equation (that is usually solved for ) is:
The CFL condition then has the following form:
where the dimensionless number is called the Courant number,
is the magnitude of the velocity (whose dimension is length/time)
is the time step (whose dimension is time)
is the length interval (whose dimension is length).
The value of changes with the method used to solve the discretised equation, especially depending on whether the method is explicit or implicit. If an explicit (time-marching) solver is used then typically . Implicit (matrix) solvers are usually less sensitive to numerical instability and so larger values of may be tolerated.
The two and general n-dimensional case
In the two-dimensional case, the CFL condition becomes
with the obvious meanings of the symbols involved. By analogy with the two-dimensional case, the general CFL condition for the -dimensional case is the following one:
The interval length is not required to be the same for each spatial variable . This "degree of freedom" can be used to somewhat optimize the value of the time step for a particular problem, by varying the values of the different interval to keep it not too small.
Notes
References
.
.: translated from the German by Phyllis Fox. This is an earlier version of the paper , circulated as a research report.
. A freely downloadable copy can be found here.
Carlos A. de Moura and Carlos S. Kubrusly (Eds.): "The Courant-Friedrichs-Lewy (CFL) Condition: 80 Years After Its Discovery", Birkhauser, ISBN 978-0-8176-8393-1 (2013).
External links
Numerical differential equations
Computational fluid dynamics | Courant–Friedrichs–Lewy condition | Physics,Chemistry | 846 |
25,547,443 | https://en.wikipedia.org/wiki/Nash%20blowing-up | In algebraic geometry, Nash blowing-up is a process in which, roughly speaking, each singular point is replaced by all limiting positions of the tangent spaces at the non-singular points. More formally, let be an algebraic variety of pure dimension r embedded in a smooth variety of dimension n, and let be the complement of the singular locus of . Define a map , where is the Grassmannian of r-planes in the tangent bundle of , by , where is the tangent space of at . The closure of the image of this map together with the projection to is called the Nash blow-up of .
Although the above construction uses an embedding, the Nash blow-up itself is unique up to unique isomorphism.
Properties
Nash blowing-up is locally a monoidal transformation.
If X is a complete intersection defined by the vanishing of then the Nash blow-up is the blow-up with center given by the ideal generated by the (n − r)-minors of the matrix with entries .
For a variety over a field of characteristic zero, the Nash blow-up is an isomorphism if and only if X is non-singular.
For an algebraic curve over an algebraically closed field of characteristic zero, repeated Nash blowing-up leads to desingularization after a finite number of steps.
Both of the prior properties may fail in positive characteristic. For example, in characteristic q > 0, the curve has a Nash blow-up which is the monoidal transformation with center given by the ideal , for q = 2, or , for . Since the center is a hypersurface the blow-up is an isomorphism.
See also
Blowing up
Resolution of singularities
References
Algebraic geometry | Nash blowing-up | Mathematics | 342 |
10,945,642 | https://en.wikipedia.org/wiki/Wildlife%20of%20Algeria | The wildlife of Algeria is composed of its flora and fauna. Mountains, chotts, wetlands, and grassy desert-like regions all support a wide range of wildlife. The most commonly seen animals include the wild boars, jackals, and gazelles, although it is not uncommon to spot fennecs and jerboas. Leopards and cheetahs are seldom seen.
A variety of bird species make the country an attraction for bird watchers. Barbary macaques are the sole native monkey.
Flora
In the north, the native flora includes the Algerian oak, Atlas cedar, and other conifers. The grape vine is indigenous to the coast. In the Sahara region, some oases have date palms. Acacia with wild olives are the predominant flora in the remainder of the Sahara.
In Algeria forest cover is around 1% of the total land area, equivalent to 1,949,000 hectares (ha) of forest in 2020, up from 1,667,000 hectares (ha) in 1990. In 2020, naturally regenerating forest covered 1,439,000 hectares (ha) and planted forest covered 510,000 hectares (ha). Of the naturally regenerating forest 0% was reported to be primary forest (consisting of native tree species with no clearly visible indications of human activity) and around 6% of the forest area was found within protected areas. For the year 2015, 80% of the forest area was reported to be under public ownership, 18% private ownership and 2% with ownership listed as other or unknown.
Fauna
Mammals
There are 104 mammal species in Algeria, of which three are critically endangered, two are endangered, ten are vulnerable, and three are near-threatened. One of the species listed for Algeria is extinct and one can no longer be found in the wild.
Atlantic spotted dolphin
Caracal
Common dolphin
Rough-toothed dolphin
Orca
Pilot whale
Pygmy killer whale
Birds
North African ostrich
Guinea fowl
Egyptian vulture
Golden eagle
Bonelli's eagle
Griffon vulture
Loons
Grebes
Great crested grebe
Little grebe
European turtle dove
Shearwaters
Black stork
White stork
Petrels
Storm-petrels
Pelicans
Gannets
Cormorant
Bitterns
Herons
Egrets
Storks
Ibises
Spoonbills
Flamingos
Ducks
Geese
Swans
Osprey
Hawks
Kites
Eagles
Caracaras
Falcon
Pheasant
Partridge
Buttonquail
Crane
Rails
Crakes
Coots
Arabian bustard
Oystercatchers
Avocet
Stilt
Thick-knee
Pratincole
Courser
Plover
Lapwing
Sandpiper
Skuas
Jaegers
Gulls
Terns
Auks
Murres
Puffins
Sandgrouse
Pigeons
Doves
Cuckoos
Great spotted woodpecker
Eurasian wryneck
Ani
Barn owls
Typical owls
Nightjars
Swifts
Kingfishers
Bee-eaters
Starling
Reptiles
Algerian sand racer
Bedriaga's fringe-fingered lizard
Boomslang
Desert monitor
Egyptian cobra
Egyptian sand boa
Erycinae
European pond terrapin
False smooth snake
Greek tortoise
Horned desert viper
Iberian wall lizard
Lataste's viper
Leatherback turtle (in the Mediterranean Sea)
Loggerhead sea turtle (in the Mediterranean Sea)
Mediterranean chameleon
Mediterranean house gecko
Moorish gecko
Müller’s sand boa
Red-tailed spiny-footed lizard
Sahara sand viper
Saharan spiny-tailed lizard
Saw-scaled viper
Small-spotted lizard
Small three-toed skink
Southern smooth snake
Two-fingered skink
Viperine water snake
Amphibians
Brongersma's toad
Common toad
European green toad
Mediterranean tree frog
Perez's frog
Sahara frog
Algerian ribbed newt
Edough ribbed newt
North African fire salamander
Fish
Atlantic bluefin tuna
Atlantic blue marlin
Atlantic white marlin
European eel
Angular roughshark
Basking shark
Bignose shark
Blacktip shark
Blacktip reef shark
Bluntnose sixgill shark
Bramble shark
Dusky shark
Great hammerhead
Great white shark
Grey nurse shark
Gulper shark
Kitefin shark
Porbeagle
Sandbar shark
Scalloped hammerhead
Sharpnose sevengill shark
Shortfin mako
Spinner shark
Velvet belly lantern shark
Insects
Acilius duvergeri
Calopteryx exul
Chalepoxenus brunneus
Desert locust
Epimyrma africana
Epimyrma algeriana
Honey bee
Monomorium noualhieri
Onychogomphus costae
Pharaoh ant
Red locust
Strongylognathus afer
Strongylognathus foreli
Other invertebrates
Brine shrimp
Common octopus
Fat-tailed scorpion
See also
Algeria
Réghaïa forest
References
Biota of Algeria
Algeria | Wildlife of Algeria | Biology | 945 |
63,122,422 | https://en.wikipedia.org/wiki/The%20Higher%20Infinite | The Higher Infinite: Large Cardinals in Set Theory from their Beginnings is a monograph in set theory by Akihiro Kanamori, concerning the history and theory of large cardinals, infinite sets characterized by such strong properties that their existence cannot be proven in Zermelo–Fraenkel set theory (ZFC). This book was published in 1994 by Springer-Verlag in their series Perspectives in Mathematical Logic, with a second edition in 2003 in their Springer Monographs in Mathematics series, and a paperback reprint of the second edition in 2009 ().
Topics
Not counting introductory material and appendices, there are six chapters in The Higher Infinite, arranged roughly in chronological order by the history of the development of the subject. The author writes that he chose this ordering "both because it provides the most coherent exposition of the mathematics and because it holds the key to any epistemological concerns".
In the first chapter, "Beginnings", the material includes inaccessible cardinals, Mahlo cardinals, measurable cardinals, compact cardinals and indescribable cardinals. The chapter covers the constructible universe and inner models, elementary embeddings and ultrapowers, and a result of Dana Scott that measurable cardinals are inconsistent with the axiom of constructibility.
The second chapter, "Partition properties", includes the partition calculus of Paul Erdős and Richard Rado, trees and Aronszajn trees, the model-theoretic study of large cardinals, and the existence of the set 0# of true formulae about indiscernibles. It also includes Jónsson cardinals and Rowbottom cardinals.
Next are two chapters on "Forcing and sets of reals" and "Aspects of measurability". The main topic of the first of these chapters is forcing, a technique introduced by Paul Cohen for proving consistency and inconsistency results in set theory; it also includes material in descriptive set theory. The second of these chapters covers the application of forcing by Robert M. Solovay to prove the consistency of measurable cardinals, and related results using stronger notions of forcing.
Chapter five is "Strong hypotheses". It includes material on supercompact cardinals and their reflection properties, on huge cardinals, on Vopěnka's principle, on extendible cardinals, on strong cardinals, and on Woodin cardinals.
The book concludes with the chapter "Determinacy", involving the axiom of determinacy and the theory of infinite games. Reviewer Frank R. Drake views this chapter, and the proof in it by Donald A. Martin of the Borel determinacy theorem, as central for Kanamori, "a triumph for the theory he presents".
Although quotations expressing the philosophical positions of researchers in this area appear throughout the book, more detailed coverage of
issues in the philosophy of mathematics regarding the foundations of mathematics are deferred to an appendix.
Audience and reception
Reviewer Pierre Matet writes that this book "will no doubt serve for many years to come as the main reference for large cardinals", and reviewers Joel David Hamkins, Azriel Lévy and Philip Welch express similar sentiments. Hamkins writes that the book is "full of historical insight, clear writing, interesting theorems, and elegant proofs". Because this topic uses many of the important tools of set theory more generally, Lévy recommends the book "to anybody who wants to start doing research in set theory", and Welch recommends it to all university libraries.
References
External links
The Higher Infinite (1st edition) at the Internet Archive
Large cardinals
Mathematics books
1994 non-fiction books
2003 non-fiction books | The Higher Infinite | Mathematics | 733 |
148,550 | https://en.wikipedia.org/wiki/Antiferromagnetism | In materials that exhibit antiferromagnetism, the magnetic moments of atoms or molecules, usually related to the spins of electrons, align in a regular pattern with neighboring spins (on different sublattices) pointing in opposite directions. This is, like ferromagnetism and ferrimagnetism, a manifestation of ordered magnetism. The phenomenon of antiferromagnetism was first introduced by Lev Landau in 1933.
Generally, antiferromagnetic order may exist at sufficiently low temperatures, but vanishes at and above the Néel temperature – named after Louis Néel, who had first in the West identified this type of magnetic ordering. Above the Néel temperature, the material is typically paramagnetic.
Measurement
When no external field is applied, the antiferromagnetic structure corresponds to a vanishing total magnetization. In an external magnetic field, a kind of ferrimagnetic behavior may be displayed in the antiferromagnetic phase, with the absolute value of one of the sublattice magnetizations differing from that of the other sublattice, resulting in a nonzero net magnetization. Although the net magnetization should be zero at a temperature of absolute zero, the effect of spin canting often causes a small net magnetization to develop, as seen for example in hematite.
The magnetic susceptibility of an antiferromagnetic material typically shows a maximum at the Néel temperature. In contrast, at the transition between the ferromagnetic to the paramagnetic phases the susceptibility will diverge. In the antiferromagnetic case, a divergence is observed in the staggered susceptibility.
Various microscopic (exchange) interactions between the magnetic moments or spins may lead to antiferromagnetic structures. In the simplest case, one may consider an Ising model on a bipartite lattice, e.g. the simple cubic lattice, with couplings between spins at nearest neighbor sites. Depending on the sign of that interaction, ferromagnetic or antiferromagnetic order will result. Geometrical frustration or competing ferro- and antiferromagnetic interactions may lead to different and, perhaps, more complicated magnetic structures.
The relationship between magnetization and the magnetizing field is non-linear like in ferromagnetic materials. This fact is due to the contribution of the hysteresis loop, which for ferromagnetic materials involves a residual magnetization.
Antiferromagnetic materials
Antiferromagnetic structures were first shown through neutron diffraction of transition metal oxides such as nickel, iron, and manganese oxides. The experiments, performed by Clifford Shull, gave the first results showing that magnetic dipoles could be oriented in an antiferromagnetic structure.
Antiferromagnetic materials occur commonly among transition metal compounds, especially oxides. Examples include hematite, metals such as chromium, alloys such as iron manganese (FeMn), and oxides such as nickel oxide (NiO). There are also numerous examples among high nuclearity metal clusters. Organic molecules can also exhibit antiferromagnetic coupling under rare circumstances, as seen in radicals such as 5-dehydro-m-xylylene.
Antiferromagnets can couple to ferromagnets, for instance, through a mechanism known as exchange bias, in which the ferromagnetic film is either grown upon the antiferromagnet or annealed in an aligning magnetic field, causing the surface atoms of the ferromagnet to align with the surface atoms of the antiferromagnet. This provides the ability to "pin" the orientation of a ferromagnetic film, which provides one of the main uses in so-called spin valves, which are the basis of magnetic sensors including modern hard disk drive read heads. The temperature at or above which an antiferromagnetic layer loses its ability to "pin" the magnetization direction of an adjacent ferromagnetic layer is called the blocking temperature of that layer and is usually lower than the Néel temperature.
Geometric frustration
Unlike ferromagnetism, anti-ferromagnetic interactions can lead to multiple optimal states (ground states—states of minimal energy). In one dimension, the anti-ferromagnetic ground state is an alternating series of spins: up, down, up, down, etc. Yet in two dimensions, multiple ground states can occur.
Consider an equilateral triangle with three spins, one on each vertex. If each spin can take on only two values (up or down), there are 23 = 8 possible states of the system, six of which are ground states. The two situations which are not ground states are when all three spins are up or are all down. In any of the other six states, there will be two favorable interactions and one unfavorable one. This illustrates frustration: the inability of the system to find a single ground state. This type of magnetic behavior has been found in minerals that have a crystal stacking structure such as a Kagome lattice or hexagonal lattice.
Other properties
Synthetic antiferromagnets (often abbreviated by SAF) are artificial antiferromagnets consisting of two or more thin ferromagnetic layers separated by a nonmagnetic layer. Dipole coupling of the ferromagnetic layers results in antiparallel alignment of the magnetization of the ferromagnets.
Antiferromagnetism plays a crucial role in giant magnetoresistance, as had been discovered in 1988 by the Nobel Prize winners Albert Fert and Peter Grünberg (awarded in 2007) using synthetic antiferromagnets.
There are also examples of disordered materials (such as iron phosphate glasses) that become antiferromagnetic below their Néel temperature. These disordered networks 'frustrate' the antiparallelism of adjacent spins; i.e. it is not possible to construct a network where each spin is surrounded by opposite neighbour spins. It can only be determined that the average correlation of neighbour spins is antiferromagnetic. This type of magnetism is sometimes called speromagnetism.
See also
References
External links
Magnetism: Models and Mechanisms in E. Pavarini, E. Koch, and U. Schollwöck: Emergent Phenomena in Correlated Matter, Jülich 2013,
Quantum phases
Magnetic ordering
Quantum lattice models
Physical phenomena | Antiferromagnetism | Physics,Chemistry,Materials_science,Engineering | 1,343 |
58,398,703 | https://en.wikipedia.org/wiki/Aspergillus%20ellipticus | Aspergillus ellipticus (also named A. helicothrix) is a species of fungus in the genus Aspergillus. A. ellipticus belongs to the group of black Aspergilli, which are important industrial workhorses. A. ellipticus belongs to the Nigri section. The species was first described in 1965, and has been shown to produce sclerotia.
The genome of A. ellipticus was sequenced and published in 2014 as part of the Aspergillus whole-genome sequencing project – a project dedicated to performing whole-genome sequencing of all members of the Aspergillus genus. The genome assembly size was 42.87 Mbp.
Growth and morphology
Aspergillus ellipticus has been cultivated on both Czapek yeast extract agar (CYA) plates and Malt Extract Agar Oxoid® (MEAOX) plates. The growth morphology of the colonies can be seen in the pictures below.
References
ellipticus
Fungi described in 1965
Fungus species | Aspergillus ellipticus | Biology | 210 |
17,563,810 | https://en.wikipedia.org/wiki/Structural%20abuse | Structural abuse is the process by which an individual or group is dealt with unfairly by a social or cultural system or authority. This unfairness manifests itself as abuse in a psychological, financial, physical or spiritual form, and victims often are unable to protect themselves from harm. An individual's inability to protect themselves may lead to their entrapment in the system, preventing them from seeking justice or recompense for crimes endured and damages incurred, creating a feeling of isolation or helplessness.
Systems containing abusive structures are primarily designed to control individuals or manipulate them for material gain. Most social systems contain at least one structure that induces structural abuse. These structures, when allowed to exist, create a cycle of abuse, wherein the abuse is repetitive or contagious in nature, and may become acceptable in other parts of the system.
Structural abuse differs to structural violence in terms of scale – structural violence is a process occurring within an entire society, such as racism or classism, while structural abuse refers to a specific element of society, or a specific system within society. Abuse occurring on this smaller scale is not necessarily endorsed by wider society, such as modern witch hunts, which have been condemned in South Africa, regardless of deaths that still occur in areas retaining anti-Pagan social structures. Structural abuse can be found on a very small scale, such as in instances of bullying involving more than one perpetrator, or in cases of malfeasance, a common example of which is individual police officers conducting investigations without direct evidence, or ignoring formal complaints made by victims.
Process
Types
There are three types of structural abuse:
Structural interference with an individual's personal health; psychological, social, emotional, physical or spiritual.
Structural interference with an individual's relationships; compromising the ability to establish and maintain social relationships – intimate or platonic.
Structural interference with an individual's liberties and rights; compromising the ability to establish and maintain employment, practicing hobbies or executing other liberties and legal rights.
Affected Groups
Structural abuse is often indirect. As such it can affect vulnerable groups, such as:
Children
Young adults
Adults with disabilities
The elderly
Nature
Structural abuses often "survive" on heuristics of fallacies and distortions of logic.
See also
Accumulation by dispossession
Causes of poverty
Conflict theories
Cultural reproduction
Civil Rights Movement
Cycle of abuse
Cycle of poverty
Discrimination
Economic abuse
Economic violence
Extermination through labour
Freak show
Frog pond effect
Global inequality
Global policeman
Golden Rule
Hate-watching
Human zoo
Imperialism
Institutional abuse
Institutional racism
Iron cage
Judicial murder
Kangaroo court
Peacebuilding
Political repression
Privilege hazard
Slow violence
Social conflict
Social exclusion
Social inequality
Social murder
Structural violence
Subsistence crisis
Suicide among LQBTQIA+ people
Symbolic violence
Toxic masculinity
War on Drugs
Washington consensus
Witch-hunts
References
Further reading
Antisocial Supply -- An educational resource to help others identify emotional and psychological abuse -- antiss.net
Psychological abuse
Abuse | Structural abuse | Biology | 587 |
54,457,304 | https://en.wikipedia.org/wiki/NGC%207057 | NGC 7057 is an elliptical galaxy located about 230 million light-years away in the constellation of Microscopium. NGC 7057 was discovered by astronomer John Herschel on September 2, 1836.
Group membership
NGC 7057 is a member of a group of galaxies known as the NGC 7060 group. Other members of the group are NGC 7060, NGC 7072 and NGC 7072A.
See also
List of NGC objects (7001–7840)
NGC 7302
References
External links
Elliptical galaxies
Microscopium
7057
66708
Astronomical objects discovered in 1836 | NGC 7057 | Astronomy | 119 |
201,912 | https://en.wikipedia.org/wiki/List%20of%20spaceflight-related%20accidents%20and%20incidents | This article lists verifiable spaceflight-related accidents and incidents resulting in human death or serious injury. These include incidents during flight or training for crewed space missions and testing, assembly, preparation, or flight of crewed and robotic spacecraft. Not included are accidents or incidents associated with intercontinental ballistic missile (ICBM) tests, fatality or injury to test animals, uncrewed space flights, rocket-powered aircraft projects of World War II, or conspiracy theories about alleged unreported Soviet space accidents.
, there have been 19 astronaut fatalities during spaceflight that either crossed, or was intended to cross, the boundary of space as defined by the United States (50 miles above sea level). Astronauts have also died while training for space missions, such as the Apollo 1 launch pad fire that killed an entire crew of three. There have also been some non-astronaut fatalities during spaceflight-related activities. As of 2025, there have been over 188 fatalities in incidents regarding spaceflight.
Astronaut fatalities
During spaceflight
, in-flight accidents have killed 15 astronauts and 4 cosmonauts in five separate incidents. Three of the flights had flown above the Kármán line (edge of space), and one was intended to do so. In each of these accidents, the entire crew was killed. , a total of 676 people have flown into space and 19 of them have died. This sets the current statistical fatality rate at 2.8 percent.
NASA astronauts who died on duty are memorialized at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Merritt Island, Florida. Cosmonauts who died on duty under the Soviet Union were generally honored by burial at the Kremlin Wall Necropolis in Moscow. No Soviet or Russian cosmonauts have died during spaceflight since 1971.
During training or testing
In addition to accidents during spaceflights, 11 astronauts, test pilots, and other personnel have been killed during training or tests.
Non-fatal incidents during spaceflight
Apart from actual disasters, 38 missions resulted in some very near misses and also some training accidents that nearly resulted in deaths.
Non-fatal training accidents
Spaceflight-related accidents and incidents during assembly, testing, and preparation for flight of crewed and uncrewed spacecraft have occasionally resulted in injuries or the loss of craft since the earliest days of space programs. 35 accidents since 2009.
Non-astronaut fatalities
Fatalities caused by rocket explosions
This list excludes deaths caused by military operations, either by deliberate detonations, or accidental during production – for example German V-2 rockets reportedly caused on average an estimated 6 deaths per operational rocket just during its production stages. Over 113 fatalities.
Other non-astronaut fatalities
47 fatalities.
See also
List of spaceflight non-fatal training accidents
Criticism of the Space Shuttle program
Fallen Astronaut
International Association for the Advancement of Space Safety
Lost Cosmonauts
Skylab 4
Effect of spaceflight on the human body
Space Shuttle
Maintenance of the International Space Station
Space station
Notes
References
Books and journals
Other online sources
External links
The Encyclopedia Astronautica
Manned space programs accident/incident summaries (1963–1969) – NASA report (PDF format)
The Crash Site of the X-15A-3
Manned space programs accident/incident summaries (1970–1971) – NASA report (PDF format)
Interactive Space Shuttle Disaster Memorial
Raw Video Reconstruction of Space Shuttle Columbia Re-entry and More
Significant Incidents & Close Calls in Human Spaceflight
Lists of disasters
Human spaceflight
Lists of people by cause of death
Accidents and incidents
Lists of transport accidents and incidents | List of spaceflight-related accidents and incidents | Engineering | 716 |
70,924 | https://en.wikipedia.org/wiki/Music%20technology%20%28electronic%20and%20digital%29 | Digital music technology encompasses the use of digital instruments to produce, perform or record music. These instruments vary, including computers, electronic effects units, software, and digital audio equipment. Digital music technology is used in performance, playback, recording, composition, mixing, analysis and editing of music, by professions in all parts of the music industry.
History
In the late 19th century, Thaddeus Cahill introduced the Telharmonium, which is commonly considered the first electromechanical musical instrument. In the early 20th century, Leon Theremin created the Theremin, an early electronic instrument played without physical contact, creating a new form of sound creation.
In the mid-20th century, sampling emerged, with artists like Pierre Schaeffer and Karlheinz Stockhausen manipulating recorded sounds on tape to create entirely new compositions. This laid the foundation for future electronic music production techniques.
In the 1960s, the Moog synthesizer, invented by Robert Moog, popularized analog synthesis. Musician Wendy Carlos demonstrated Robert's invention with the album Switched-On Bach, which consisted of works composed by Johann Sebastian Bach interpreted with the Moog synthesizer. Meanwhile, tape-based studios, like the BBC Radiophonic Workshop, were at the forefront of electronic sound design.
The 1980s saw a major shift towards digital technology with the development of the Musical Instrument Digital Interface (MIDI) standard. This allowed electronic instruments to communicate with computers and each other, transforming music production. Digital synthesizers, such as the Yamaha DX7, became widely popular.
The 1990s and 2000s witnessed the explosive growth of electronic dance music and its various subgenres, driven by the accessibility of digital music production tools and the rise of computer-based software synthesizers.
Education
Professional training
Courses in music technology are offered at many different universities as part of degree programs focusing on performance, composition, music research at the undergraduate and graduate level. The study of music technology is usually concerned with the creative use of technology for creating new sounds, performing, recording, programming sequencers or other music-related electronic devices, and manipulating, mixing and reproducing music. Music technology programs train students for careers in "...sound engineering, computer music, audio-visual production and post-production, mastering, scoring for film and multimedia, audio for games, software development, and multimedia production." Those wishing to develop new music technologies often train to become an audio engineer working in research and development. Due to the increasing role of interdisciplinary work in music technology, individuals developing new music technologies may also have backgrounds or training in electrical engineering, computer programming, computer hardware design, acoustics, record producing or other fields.
Use of music technology in education
Digital music technologies are widely used to assist in music education for training students in the home, elementary school, middle school, high school, college and university music programs. Electronic keyboard labs are used for cost-effective beginner group piano instruction in high schools, colleges, and universities. Courses in music notation software and basic manipulation of audio and MIDI can be part of a student's core requirements for a music degree. Mobile and desktop applications are available to aid the study of music theory and ear training. Some digital pianos provide interactive lessons and games using the built-in features of the instrument to teach music fundamentals.
Analog Synthesizers
Classic analog synthesizers include the Moog Minimoog, ARP Odyssey, Yamaha CS-80, Korg MS-20, Sequential Circuits Prophet-5, Roland TB-303, Roland Alpha Juno. One of the most iconic synthesizers is the Roland TB-303, was widely used in acid house music.
Digital synthesizer history
Classic digital synthesizers include the Fairlight CMI, PPG Wave, Nord Modular and Korg M1.
Computer music history
Max Mathews
Computer and synthesizer technology joining together changed the way music is made and is one of the fastest-changing aspects of music technology today. Max Mathews, an acoustic researcher at Bell Telephone Laboratories' Acoustic and Behavioural Research Department, is responsible for some of the first digital music technology in the 1950s. Mathews also pioneered a cornerstone of music technology; analog-to-digital conversion.
At Bell Laboratories, Matthews conducted research to improve the telecommunications quality for long-distance phone calls. Owing to long-distance and low-bandwidth, audio quality over phone calls across the United States was poor. Thus, Matthews devised a method in which sound was synthesized via computer on the distant end rather than transmitted. Matthews was an amateur violinist, and during a conversation with his superior, John Pierce at Bell Labs, Pierce posed the idea of synthesizing music through a computer. Since Matthews had already synthesized speech, he agreed and wrote a series of programs known as MUSIC. MUSIC consisted of two files: an orchestra file containing data telling the computer how to synthesize sound, and a score file instructing the program what notes to play using the instruments defined in the orchestra file. Matthews wrote five iterations of MUSIC, calling them MUSIC I-V respectively. Subsequently, as the program was adapted and expanded to run on various platforms, its name changed to reflect its new changes. This series of programs became known as the MUSIC-N paradigm. The concept of the MUSIC now exists in the form of Csound.
Later Max Matthews worked as an advisor to IRCAMin the late 1980s. There, he taught Miller Puckette, a researcher. Puckette developed a program in which music could be programmed graphically. The program could transmit and receive MIDI messages to generate interactive music in real-time. Inspired by Matthews, Puckette named the program Max. Later, a researcher named David Zicarelli visited IRCAM, saw the capabilities of Max and felt it could be developed further. He took a copy of Max with him when he left and eventually added capabilities to process audio signals. Zicarelli named this new part of the program MSP after Miller Puckette. Zicarelli developed the commercial version of MaxMSP and sold it at his company, Cycling '74, beginning in 1997. The company has since been acquired by Ableton.
Later history
The first generation of professional commercially available computer music instruments, or workstations as some companies later called them, were very sophisticated elaborate systems that cost a great deal of money when they first appeared. They ranged from $25,000 to $200,000. The two most popular were the Fairlight, and the Synclavier.
It was not until the advent of MIDI that general-purpose computers started to play a role in music production. Following the widespread adoption of MIDI, computer-based MIDI editors and sequencers were developed. MIDI-to-CV/Gate converters were then used to enable analogue synthesizers to be controlled by a MIDI sequencer.
Reduced prices in personal computers caused the masses to turn away from the more expensive workstations. Advancements in technology have increased the speed of hardware processing and the capacity of memory units. Powerful programs for sequencing, recording, notating, and mastering music.
MIDI history
At the NAMM Show of 1983 in Los Angeles, MIDI was released. A demonstration at the convention showed two previously incompatible analog synthesizers, the Prophet 600 and Roland Jupiter-6, communicating with each other, enabling a player to play one keyboard while getting the output from both of them. This was a massive breakthrough in the 1980s, as it allowed synths to be accurately layered in live shows and studio recordings. MIDI enables different electronic instruments and electronic music devices to communicate with each other and with computers. The advent of MIDI spurred a rapid expansion of the sales and production of electronic instruments and music software.
In 1985, several of the top keyboard manufacturers created the MIDI Manufacturers Association (MMA). This newly founded association standardized the MIDI protocol by generating and disseminating all the documents about it. With the development of the MIDI File Format Specification by Opcode, every music software company's MIDI sequencer software could read and write each other's files.
Since the 1980s, personal computers developed and became the ideal system for utilizing the vast potential of MIDI. This has created a large consumer market for software such as MIDI-equipped electronic keyboards, MIDI sequencers and digital audio workstations. With universal MIDI protocols, electronic keyboards, sequencers, and drum machines can all be connected together.
Vocal synthesis history until 1980s
VODER on Bell Lab.
Coinciding with the history of computer music is the history of vocal synthesis. Prior to Max Matthews synthesizing speech with a computer, analog devices were used to recreate speech. In the 1930s, an engineer named Holmer Dudley invented the VODER (Voice Operated Demonstrator), an electro-mechanical device which generated a sawtooth wave and white-noise. Various parts of the frequency spectrum of the waveforms could be filtered to generate the sounds of speech. Pitch was modulated via a bar on a wrist strap worn by the operator. In the 1940s Dudley, invented the VOCODER (Voice Operated Coder). Rather than synthesizing speech from scratch, this machine operated by accepting incoming speech and breaking it into its spectral components. In the late 1960s and early 1970s, bands and solo artists began using the VOCODER to blend speech with notes played on a synthesizer.
Singing Kelly-Lochbaum Vocal Tract on Bell Lab.
Meanwhile, at Bell Laboratories, Max Matthews worked with researchers Kelly and Lochbaum to develop a model of the vocal tract to study how its prosperities contributed to speech generation. Using the model of the vocal tract, —a method in which a computer estimates the formants and spectral content of each word based on information about the vocal model, including various applied filters representing the vocal tract—to make a computer (an IBM 704) sing for the first time in 1962. The computer performed a rendition of "Daisy Bell".
CHANT on IRCAM
At IRCAM in France, researchers developed software called CHANT (French for "sing"), the first version of which ran between 1979 and 1983. CHANT was based FOF () synthesis, in which the peak frequencies of a sound are created and shaped using granular synthesis—as opposed to filtering frequencies to create speech.
Concatenation synthesis using MIDI
Through the 1980s and 1990s as MIDI devices became commercially available, speech was generated by mapping MIDI data to samples of the components of speech stored in sample libraries.
Vocal synthesis after 2010s
In the 2010s, Singing synthesis technology has taken advantage of the recent advances in artificial intelligence—deep listening and machine learning to better represent the nuances of the human voice. New high fidelity sample libraries combined with digital audio workstations facilitate editing in fine detail, such as shifting of formats, adjustment of vibrato, and adjustments to vowels and consonants. Sample libraries for various languages and various accents are available. With today's advancements in vocal synthesis, artists sometimes use sample libraries in lieu of backing singers.
Synthesizers and drum machines
Synthesizers
A synthesizer is an electronic musical instrument that generates electric signals that are converted to sound through instrument amplifiers and loudspeakers or headphones. Synthesizers may either imitate existing sounds (instruments, vocal, natural sounds, etc.), or generate new electronic timbres or sounds that did not exist before. They are often played with an electronic musical keyboard, but they can be controlled via a variety of other input devices, including music sequencers, instrument controllers, fingerboards, guitar synthesizers, wind controllers, and electronic drums. Synthesizers without built-in controllers are often called sound modules, and are controlled using a controller device.
Synthesizers use various methods to generate a signal. Among the most popular waveform synthesis techniques are subtractive synthesis, additive synthesis, wavetable synthesis, frequency modulation synthesis, phase distortion synthesis, physical modeling synthesis and sample-based synthesis. Other less common synthesis types include subharmonic synthesis, a form of additive synthesis via subharmonics (used by Mixtur-Trautonium), and granular synthesis, sample-based synthesis based on grains of sound, generally resulting in soundscapes or clouds. In the 2010s, synthesizers are used in many genres of pop, rock and dance music. Contemporary classical music composers from the 20th and 21st century write compositions for synthesizer.
Drum machines
A drum machine is an electronic musical instrument designed to imitate the sound of drums, cymbals, other percussion instruments, and often basslines. Drum machines either play back prerecorded samples of drums and cymbals or synthesized re-creations of drum/cymbal sounds in a rhythm and tempo that is programmed by a musician. Drum machines are most commonly associated with electronic dance music genres such as house music, but are also used in many other genres. They are also used when session drummers are not available or if the production cannot afford the cost of a professional drummer. In the 2010s, most modern drum machines are sequencers with a sample playback (rompler) or synthesizer component that specializes in the reproduction of drum timbres. Though features vary from model to model, many modern drum machines can also produce unique sounds, and allow the user to compose unique drum beats and patterns.
Electro-mechanical drum machines were first developed in 1949, with the invention of the Chamberlin Rhythmate. Transistorized electronic drum machines Seeburg Select-A-Rhythm appeared in 1964.
Classic drum machines include the Korg Mini Pops 120, PAiA Programmable Drum Set, Roland CR-78, LinnDrum, Roland TR-909, Oberheim DMX, E-MU SP-12, Alesis HR-16, and Elektron SPS1 Machinedrum (in chronological order).
Drum machines in Japan
In the late 1970s and 1980s, Japanese manufacturers, including Roland and Korg, assumed pivotal roles in the transformation of the musical landscape. Roland's TR-808 and TR-909 significantly changed the landscape of rhythm production. shaping genres like hip-hop and electronic dance music. Korg's KPR-77 and DDD-1 also made an impact. These drum machines were known for their distinctive sound and affordability. Over time, Japanese companies continued to innovate, producing increasingly sophisticated and user-friendly drum machines, such as the Roland TR-8 and Korg Volca Beats. These instruments continue to influence contemporary music production and remain integral to the electronic music landscape worldwide.Sly and the Family Stone's 1971 album There's a Riot Goin' On helped to popularize the sound of early drum machines, along with Timmy Thomas' 1972 R&B hit "Why Can't We Live Together" and George McCrae's 1974 disco hit "Rock Your Baby" which used early Roland rhythm machines.
Early drum machines sounded drastically different than the drum machines that gained their peak popularity in the 1980s and defined an entire decade of pop music. The most iconic drum machine was the Roland TR-808, widely used in hip hop and dance music.
Sampling technology after 1980s
Digital sampling technology, introduced in the 1970s, Devices that use sampling, record a sound digitally (often a musical instrument, such as a piano or flute being played), and replay it when a key or pad on a controller device (e.g., an electronic keyboard, electronic drum pad, etc.) is pressed or triggered. Samplers can alter the sound using various audio effects and audio processing. Sampling has its roots in France with the sound experiments carried out by musique concrète practitioners.
In the 1980s, when the technology was still in its infancy, digital samplers cost tens of thousands of dollars and they were only used by the top recording studios and musicians. These were out of the price range of most musicians. Early samplers include the 8-bit Electronic Music Studios MUSYS-3 circa 1970, Computer Music Melodian in 1976, Fairlight CMI in 1979, Emulator I in 1981, Synclavier II Sample-to-Memory (STM) option circa 1980, Ensoniq Mirage in 1984, and Akai S612 in 1985. The latter's successor, the Emulator II (released in 1984), listed for $8,000. Samplers were released during this period with high price tags, such as the K2000 and K2500.
Some important hardware samplers include the Kurzweil K250, Akai MPC60, Ensoniq Mirage, Ensoniq ASR-10, Akai S1000, E-mu Emulator, and Fairlight CMI.
One of the biggest uses of sampling technology was by hip-hop music DJs and performers in the 1980s. Before affordable sampling technology was readily available, DJs would use a technique pioneered by Grandmaster Flash to manually repeat certain parts in a song by juggling between two separate turntables. This can be considered as an early precursor of sampling. In turn, this turntablism technique originates from Jamaican dub music in the 1960s and was introduced to American hip hop in the 1970s.
In the 2000s, most professional recording studios use digital technologies. In recent years, many samplers have only included digital technology. This new generation of digital samplers are capable of reproducing and manipulating sounds. Digital sampling plays an integral part in some genres of music, such as hip-hop and trap. Advanced sample libraries have made complete performances of orchestral compositions possible that sound similar to a live performance. Modern sound libraries allow musicians to have the ability to use the sounds of almost any instrument in their productions.
Sampling technology in Japan
Early samplers include the 12-bit Toshiba in 1981.
The first affordable sampler in Japan was the Ensoniq Mirage in 1984. Also the AKAI S612 became available in 1985, retailed for US$895. Other companies soon released affordable samplers, including Oberheim DPX-1 in 1987, and more by Korg, Casio, Yamaha, and Roland. Some important hardware samplers in Japan include the Akai Z4/Z8, Roland V-Synth, Casio FZ-1.
MIDI
MIDI has been the musical instrument industry standard interface since the 1980s through to the present day. It dates back to June 1981, when Roland Corporation founder Ikutaro Kakehashi proposed the concept of standardization between different manufacturers' instruments as well as computers, to Oberheim Electronics founder Tom Oberheim and Sequential Circuits president Dave Smith. In October 1981, Kakehashi, Oberheim and Smith discussed the concept with representatives from Yamaha, Korg and Kawai. In 1983, the MIDI standard was unveiled by Kakehashi and Smith.
Some universally accepted varieties of MIDI software applications include music instruction software, MIDI sequencing software, music notation software, hard disk recording/editing software, patch editor/sound library software, computer-assisted composition software, and virtual instruments. Current developments in computer hardware and specialized software continue to expand MIDI applications.
Computers in music technology after 1980s
Following the widespread adoption of MIDI, computer-based MIDI editors and sequencers were developed. MIDI-to-CV/Gate converters were then used to enable analogue synthesizers to be controlled by a MIDI sequencer.
Reduced prices in personal computers caused the masses to turn away from the more expensive workstations. Advancements in technology have increased the speed of hardware processing and the capacity of memory units. Software developers write new, more powerful programs for sequencing, recording, notating, and mastering music.
Digital audio workstation software, such as Pro Tools, Logic, and many others, have gained popularity among the vast array of contemporary music technology in recent years. Such programs allow the user to record acoustic sounds with a microphone or software instrument, which may then be layered and organized along a timeline and edited on a flat-panel display of a computer. Recorded segments can be copied and duplicated ad infinitum, without any loss of fidelity or added noise (a major contrast from analog recording, in which every copy leads to a loss of fidelity and added noise). Digital music can be edited and processed using a multitude of audio effects. Contemporary classical music sometimes uses computer-generated sounds—either pre-recorded or generated and manipulated live—in conjunction or juxtaposed on classical acoustic instruments like the cello or violin. Music is scored with commercially available notation software.
In addition to the digital audio workstations and music notation software, which facilitate the creation of fixed media (material that does not change each time it is performed), software facilitating interactive or generative music continues to emerge. Composition based on conditions or rules (algorithmic composition) has given rise to software which can automatically generate music based on input conditions or rules. Thus, the resulting music evolves each time conditions change. Examples of this technology include software designed for writing music for video games—where music evolves as a player advances through a level or when certain characters appear—or music generated from artificial intelligence trained to convert biometrics like EEG or ECG readings into music. Because this music is based on user interaction, it will be different each time it is heard. Other examples of generative music technology include the use of sensors connected to computer and artificial intelligence to generate music based on captured data, such as environmental factors, the movements of dancers, or physical inputs from a digital device such as a mouse or game controller. Software applications offering capabilities for generative and interactive music include SuperCollider, MaxMSP/Jitter, and Processing. Interactive music is made possible through physical computing, where the data from the physical world affects a computer's output and vice versa.
Timeline
1917 : Leon Theremin invented the prototype of the Theremin
1944 : Halim El-Dabh produces earliest electroacoustic tape music
1952 : Harry F. Olson and Herbert Belar invent the RCA Synthesizer
1952 : Osmand Kendal develops the Composer-Tron for the Marconi Wireless Company
1956 : Raymond Scott develops the Clavivox
1958 : Yevgeny Murzin along with several colleagues create the ANS synthesizer
1959 : Wurlitzer manufactures The Sideman, the first commercial electro-mechanical drum machine
1963 : The Mellotron starts to be manufactured in London
1964 : The Moog synthesizer is released
1968 : King Tubby pioneers dub music, an early form of popular electronic music
1970 : ARP 2600 is manufactured
1982 : Sony and Philips introduce compact disc
1983 : Introduction of MIDI
1986 : The first digital consoles appear
1987 : Digidesign markets Sound Tools
Timeline in Japan
1963 : Keio Electronics (later Korg) produces the DA-20
1964 : Ikutaro Kakehashi debuts Ace Tone R-1 Rhythm Ace, the first electronic drum
1965 : Nippon Columbia patents an early electronic drum machine
1966 : Korg releases Donca-Matic DE-20, an early electronic drum machine
1967 : Ace Tone releases FR-1 Rhythm Ace, the first drum machine to enter popular music
1967 : First PCM recorder developed by NHK
1969 : Matsushita engineer Shuichi Obata invents first direct-drive turntable, Technics SP-10
1973 : Yamaha release Yamaha GX-1, the first polyphonic synthesizer
1974 : Yamaha build first digital synthesizer
1977 : Roland release MC-8, an early microprocessor-driven CV/Gate digital sequencer
1978 : Roland releases CR-78, the first microprocessor-driven drum machine
1979 : Casio releases VL-1, the first commercial digital synthesizer
1980 : Roland releases TR-808, the most widely used drum machine in popular music
1980 : Roland introduces DCB protocol and DIN interface with TR-808
1980 : Yamaha releases GS-1, the first FM digital synthesizer
1980 : Kazuo Morioka creates Firstman SQ-01, the first bass synth with a sequencer
1981 : Roland releases TB-303, a bass synthesizer that lays foundations for acid house music
1981 : Toshiba's , the first PCM digital sampler in Japan, introduced with Yellow Magic Orchestra's Technodelic
1982 : First MIDI synthesizers released, Roland Jupiter-6 and Prophet 600
1983 : Roland releases MSQ-700, the first MIDI sequencer
1983 : Roland releases TR-909, the first MIDI drum machine
1983 : Yamaha releases DX7, the first commercially successful digital synthesizer
1985 : Akai releases the Akai S612, a digital sampler
1988 : Akai introduces the Music Production Controller (MPC) series of digital samplers
1994 : Yamaha unveils the ProMix 01
See also
List of music software
References
Further reading
Sound recording
Audio electronics
Audio software
Music history
Musical instruments | Music technology (electronic and digital) | Engineering | 4,964 |
59,803,665 | https://en.wikipedia.org/wiki/Grizzly%20399 | Grizzly 399 (1996 – October 22, 2024) was a grizzly bear living in Grand Teton National Park and Bridger-Teton National Forest in Wyoming, United States. She was followed by as many as 40 wildlife photographers, and millions of tourists came to the Greater Yellowstone Ecosystem to see her and other grizzly bears. There are official Facebook, Twitter, and Instagram accounts for Grizzly 399.
Background
Grizzly bears (Ursus arctos horribilis) are a subspecies of the North American Brown bear species U. arctos. Several decades ago, grizzlies were assessed as being at risk of rapid extinction due to the rate at which the population was declining. Protection under the Endangered Species Act of 1973 has resulted in a population rebound: there are now approximately 2,000 grizzly bears in the contiguous United States, of which about half are estimated to live in the Greater Yellowstone Ecosystem. Grizzlies are stereotyped as ferocious, but the typical bear avoids contact with humans, living away from settlements and attacking only to protect themselves when startled by a human.
Life
Grizzly 399 was a grizzly bear who resided on federal land in a range of hundreds of miles throughout the Grand Teton National Park and the Bridger-Teton National Forest. She was born in a den in Pilgrim Creek, Wyoming, in the winter of 1996. She was captured in 2001 and fitted with a radio collar by the Interagency Grizzly Bear Study Team. She was the 399th bear to be tracked with this method as part of the long-term research project. In 2018, monitoring of 399 via radio telemetry ceased, with the research continuing as she resided in an area where she was easily observable.
399 reached age 28, becoming older than is usual for a grizzly bear, as "more than 85 percent of them are killed because of some kind of human activity before they reach old age". She weighed almost . When standing upright on her hind legs, she was . Unlike the typical grizzly, she lived in close proximity to humans, although she was not particularly concerned with their presence; scientists have speculated that this was in response to a death of a cub in a more remote area, so she wanted to avoid that area. She never killed a human despite at least two known close encounters.
Cubs
Grizzly 399 successfully reared many progeny, including 22 cubs and grandcubs. In mid-May 2020 she was observed with four new cubs born the previous winter. She taught her offspring habits to benefit from rather than be harmed by human proximity, such as loitering during the fall elk hunt to consume abandoned elk innards and looking both ways before crossing roadways to avoid being struck by vehicles, a common cause of death among bears.
Despite this, at least three of her cubs were killed due to human encounters, including Grizzly 399's only 2016 cub, nicknamed "Snowy" because of his whitish-blonde facial coloration. In June of that year, Snowy was struck and killed by a car in Grand Teton National Park, an incident investigated as a potential hit-and-run accident. In all, she lost half of her descendants due to encounters with people or male bears.
On May 21, 2020, a wildlife photographer saw Grizzly 399 coming out of hibernation in Pilgrim Creek with four cubs. This was her largest brood to date. On May 16, 2023, Grizzly 399 emerged from hibernation and appeared in the area of Pilgrim Creek in Grand Teton National Park. She was seen with a single cub. At age 26 or 27, this made her the oldest female bear known to have reproduced in the Greater Yellowstone Ecosystem.
Unlike the typical bear, Grizzly 399 regularly gave birth to triplets rather than twins. This typically has a paradoxical effect on the bear population. A mother bear with three cubs expends significantly more energy in caring for them, which can potentially decrease rather than increase the survival rate. Grizzly 399, conversely, typically handled triplets well. One of her triplet cubs also grew to be a prolific mother and was tagged for research as Grizzly 610. In 2011, Grizzly 610 had twins, while Grizzly 399 had another set of triplets. The scientists observing the bears were concerned due to 399's advanced age, but to their surprise Grizzly 610 amicably adopted one of her mother's triplet cubs.
One of 399's 2017 twin cubs, numbered 964, was relocated to Yellowstone in 2019. She was spotted with twins in 2023. Grizzly 610's daughter, numbered 926, released twins in 2023.
Relationship with humans
Grizzly 399 was known to be habituated to people when near roads and lightly developed areas. A researcher determined that she sought out these roadside areas rather than backcountry because it was safer for her cubs, which male bears often attempted to kill. The fact that she spent so much time near roads also contributed to her popularity. In 2011, the sight of a mother grizzly bear and her three cubs near a road in central Grand Teton National Park was enough to cause traffic to come to a halt in both directions for miles. In Willow Flats, Grizzly 399 taught each set of cubs to hunt elk calves, within view of the guests at Jackson Lake Lodge.
Grizzly 399 was usually found along the roadside near the Oxbow Bend of the Snake River. The number of photographers following her grew to approximately 40–50 by of 2015. 399 was considered the "grand matriarch of the park's roadside bears."
In 2016, Grizzly 399 was feared dead after a hunter claimed to have killed her; however, she emerged from hibernation on May 10, 2016, with one cub in tow. She emerged from the Bridger-Teton National Forest into the Grand Teton National Park with a white-faced cub at her side. In 2017, now older than the age beyond which most brown bears usually breed, she was spotted in a spring snowstorm with two cubs following her.
Death
On the evening of October 22, 2024, Grizzly 399 was fatally struck by a vehicle on Highway 26/89 in Snake River Canyon, south of Jackson, Wyoming. The bear's identity was confirmed through ear tags and a microchip.
Grand Teton Wildlife Brigade
Created in 2007 in response to the magnitude of visitors coming to Grand Teton to view Grizzly 399 and her cubs, the Grand Teton Wildlife Brigade keeps animals and people apart and safe. In 2011, ranger Kate Wilmot, whose official title is "bear management specialist", said that that year things had become "completely chaotic". The real duty was managing the behavior of park visitors. This was partly due to social media increasing the popularity of the bears, and drawing more people to seek them out.
Wilmot directs 16 volunteers in the brigade throughout the summer until snowfall. If not for the brigaders, "wildlife watching would be a mess". The brigaders carry bear spray, but their primary role is to persuade tourists to respect the 100-yard viewing guideline established after incidents with Grizzly 610, 399's daughter.
Feeding the bears is illegal, so the brigadiers prevent this. If bears receive food from people, they can become habituated to people and more aggressive toward them. The brigadiers remind tourists of their role in respecting bears' space. The brigadiers' success can be measured in the rarity of major incidents and bear removals from the park. When bears become too habituated to human presence and aggressive in their pursuit of human food, or when a bear attacks a human, the "problem bear" is typically euthanized. Grizzly mothers are known for being aggressively protective of their progeny. In 2011, in Yellowstone National Park, a mother bear fatally mauled a hiker who got too close. Grizzly 610, 399's daughter, twice "charged" tourists who got too close. No injuries were reported.
Endangered species protection and hunting
In 2017, the United States Fish and Wildlife Service officials removed grizzly bears from the endangered species list and turned management of grizzlies outside Yellowstone and Grand Teton National Parks over to Wyoming, Montana, and Idaho. Grizzlies live in ranges covering hundreds of miles, which can place them outside of parks, where they become the targets of hunters. Grizzly 399 lived outside of the parks.
Hunters in the area targeted 399 because she was the biggest and most famous trophy. Daryl Hunter, a wildlife photographer who followed Grizzly 399, related a conversation with an outfitter who said, "I met a guy who wants Grizzly 399's rug on his wall, stating that because she is famous, she makes a better trophy". Grizzly 399 spent part of the year in Grand Teton National Park, but also hibernated in the national forest where hunting is allowed.
For the 2018 hunting season, Montana decided against a hunt. Idaho, with the fewest grizzlies, decided to allow hunting of only one bear. On May 23, 2018, the Wyoming wildlife commission voted unanimously to approve a grizzly bear hunt. The Wyoming Game and Fish Department let a vote decide the number of grizzlies to be killed. The tally came to 22 grizzlies in a unanimous vote of 7–0. The hunting season was planned for September 15 to November 15. This was to be the first authorized hunt in Wyoming in 44 years - since 1975 - a time when they were first listed as endangered, when no hunting was allowed inside the national parks or on the connecting road between them, and when the grizzly population had fallen to around 136 individuals.
Wyoming's planned hunt met with a public outcry. Five women in Jackson Hole quickly organized "Shoot'em With A Camera-Not A Gun", which encouraged opponents of trophy hunting to join the tag lottery in hopes of preventing hunters from winning tags. Approximately 7,000 people applied for Wyoming bear tags, including wildlife photographer Thomas D. Mangelsen, Jane Goodall, and other conservationists.
In July 2018, Mangelsen learned he was positioned high enough on a hunting lottery to actually receive a hunting tag, as he held slot number 8 in the queue. In September, just weeks before hunting season was to begin, a federal judge in Montana restored protection to all of the bears in the Greater Yellowstone Ecosystem. The judge ruled that the United States Fish and Wildlife Service officials were "arbitrary and capricious" when they removed protection from the bears under the Endangered Species Act of 1973. In July 2020, the Ninth Circuit Court of Appeals upheld the Montana judge's ruling.
In March 2021, the U.S. Fish and Wildlife Service recommended no change to the protection status of the grizzly bear in the lower-48 states. According to the ESA after a five-year status review, they remained threatened .
In popular culture
Books
Grizzly 399: The Story of a Remarkable Bear is a children's book published in May 2020 in Idaho Falls. The book is written by Sylvia M. Medina, illustrated by Morgan Spicer and includes photographs by American nature and wildlife photographer, Thomas D. Mangelsen. The publisher published a subsequent book with the same author, illustrator and photographer in April 2021 to include Grizzly 399's new cubs, titled, "Grizzly 399's Hibernation Pandemonium" after the 24-year-old mother bear surprised the world with the birth of four more cubs in the spring of 2020.
Grizzlies of Pilgrim Creek In 2015, Thomas D. Mangelsen collaborated with Wilkinson to create the book about Grizzly 399 and her progeny. Mangelsen made it one of his priorities for over ten years to record her life, including her hibernation schedule, feeding, and mothering; he recorded the birth of three sets of triplets and a set of twins. His photographs, especially the one he dubbed, "An Icon of Motherhood", helped make her the most famous mother grizzly, maybe the most famous grizzly, in the world. Millions of people visit the Greater Yellowstone Ecosystem just to see these grizzly bears.
Facebook account
By 2015, Grizzly 399 had a full social media presence, although it was a mystery who is running the accounts. She had her own Facebook page, Instagram account, and a Twitter handle. "These aren't just any bears", explained Thomas D. Mangelsen, a global wildlife photographer who lives in Jackson Hole, Wyoming, "They might be the most famous grizzlies alive today on the planet. For all these people, catching a glimpse of them is the thrill of a lifetime." Mangelsen followed her movements for over ten years. Grizzly 399 dispelled the stereotype that all grizzlies are agents of terror, wrote Bozeman author Todd Wilkinson: "She's more well-behaved a lot of times than people around her. But she's wild."
See also
List of individual bears
References
External links
Grand Teton Parks Grizzly Bears 399 & 610 − YouTube
Always Endangered − The Story of Grizzly 399 − YouTube
Grizzlies of Pilgrim Creek (Book Trailer) − YouTube
VIDEO: Grizzly 399 and cubs | Multimedia | jhnewsandguide.com
PBS Nature "Grizzly 399: Queen of the Tetons" full episode
1996 animal births
2024 animal deaths
Individual grizzly bears
Female mammals
Roadkill
Road incident deaths in Wyoming
Individual animals in the United States | Grizzly 399 | Engineering,Biology | 2,791 |
28,356 | https://en.wikipedia.org/wiki/Symplectic%20manifold | In differential geometry, a subject of mathematics, a symplectic manifold is a smooth manifold, , equipped with a closed nondegenerate differential 2-form , called the symplectic form. The study of symplectic manifolds is called symplectic geometry or symplectic topology. Symplectic manifolds arise naturally in abstract formulations of classical mechanics and analytical mechanics as the cotangent bundles of manifolds. For example, in the Hamiltonian formulation of classical mechanics, which provides one of the major motivations for the field, the set of all possible configurations of a system is modeled as a manifold, and this manifold's cotangent bundle describes the phase space of the system.
Motivation
Symplectic manifolds arise from classical mechanics; in particular, they are a generalization of the phase space of a closed system. In the same way the Hamilton equations allow one to derive the time evolution of a system from a set of differential equations, the symplectic form should allow one to obtain a vector field describing the flow of the system from the differential of a Hamiltonian function . So we require a linear map from the tangent manifold to the cotangent manifold , or equivalently, an element of . Letting denote a section of , the requirement that be non-degenerate ensures that for every differential there is a unique corresponding vector field such that . Since one desires the Hamiltonian to be constant along flow lines, one should have , which implies that is alternating and hence a 2-form. Finally, one makes the requirement that should not change under flow lines, i.e. that the Lie derivative of along vanishes. Applying Cartan's formula, this amounts to (here is the interior product):
so that, on repeating this argument for different smooth functions such that the corresponding span the tangent space at each point the argument is applied at, we see that the requirement for the vanishing Lie derivative along flows of corresponding to arbitrary smooth is equivalent to the requirement that ω should be closed.
Definition
A symplectic form on a smooth manifold is a closed non-degenerate differential 2-form . Here, non-degenerate means that for every point , the skew-symmetric pairing on the tangent space defined by is non-degenerate. That is to say, if there exists an such that for all , then . Since in odd dimensions, skew-symmetric matrices are always singular, the requirement that be nondegenerate implies that has an even dimension. The closed condition means that the exterior derivative of vanishes. A symplectic manifold is a pair where is a smooth manifold and is a symplectic form. Assigning a symplectic form to is referred to as giving a symplectic structure.
Examples
Symplectic vector spaces
Let be a basis for We define our symplectic form ω on this basis as follows:
In this case the symplectic form reduces to a simple quadratic form. If In denotes the n × n identity matrix then the matrix, Ω, of this quadratic form is given by the block matrix:
Cotangent bundles
Let be a smooth manifold of dimension . Then the total space of the cotangent bundle has a natural symplectic form, called the Poincaré two-form or the canonical symplectic form
Here are any local coordinates on and are fibrewise coordinates with respect to the cotangent vectors . Cotangent bundles are the natural phase spaces of classical mechanics. The point of distinguishing upper and lower indexes is driven by the case of the manifold having a metric tensor, as is the case for Riemannian manifolds. Upper and lower indexes transform contra and covariantly under a change of coordinate frames. The phrase "fibrewise coordinates with respect to the cotangent vectors" is meant to convey that the momenta are "soldered" to the velocities . The soldering is an expression of the idea that velocity and momentum are colinear, in that both move in the same direction, and differ by a scale factor.
Kähler manifolds
A Kähler manifold is a symplectic manifold equipped with a compatible integrable complex structure. They form a particular class of complex manifolds. A large class of examples come from complex algebraic geometry. Any smooth complex projective variety has a symplectic form which is the restriction of the Fubini—Study form on the projective space .
Almost-complex manifolds
Riemannian manifolds with an -compatible almost complex structure are termed almost-complex manifolds. They generalize Kähler manifolds, in that they need not be integrable. That is, they do not necessarily arise from a complex structure on the manifold.
Lagrangian and other submanifolds
There are several natural geometric notions of submanifold of a symplectic manifold :
Symplectic submanifolds of (potentially of any even dimension) are submanifolds such that is a symplectic form on .
Isotropic submanifolds are submanifolds where the symplectic form restricts to zero, i.e. each tangent space is an isotropic subspace of the ambient manifold's tangent space. Similarly, if each tangent subspace to a submanifold is co-isotropic (the dual of an isotropic subspace), the submanifold is called co-isotropic.
Lagrangian submanifolds of a symplectic manifold are submanifolds where the restriction of the symplectic form to is vanishing, i.e. and . Lagrangian submanifolds are the maximal isotropic submanifolds.
One major example is that the graph of a symplectomorphism in the product symplectic manifold is Lagrangian. Their intersections display rigidity properties not possessed by smooth manifolds; the Arnold conjecture gives the sum of the submanifold's Betti numbers as a lower bound for the number of self intersections of a smooth Lagrangian submanifold, rather than the Euler characteristic in the smooth case.
Examples
Let have global coordinates labelled . Then, we can equip with the canonical symplectic form
There is a standard Lagrangian submanifold given by . The form vanishes on because given any pair of tangent vectors we have that To elucidate, consider the case . Then, and . Notice that when we expand this out
both terms we have a factor, which is 0, by definition.
Example: Cotangent bundle
The cotangent bundle of a manifold is locally modeled on a space similar to the first example. It can be shown that we can glue these affine symplectic forms hence this bundle forms a symplectic manifold. A less trivial example of a Lagrangian submanifold is the zero section of the cotangent bundle of a manifold. For example, let
Then, we can present as
where we are treating the symbols as coordinates of . We can consider the subset where the coordinates and , giving us the zero section. This example can be repeated for any manifold defined by the vanishing locus of smooth functions and their differentials .
Example: Parametric submanifold
Consider the canonical space with coordinates . A parametric submanifold of is one that is parameterized by coordinates such that
This manifold is a Lagrangian submanifold if the Lagrange bracket vanishes for all . That is, it is Lagrangian if
for all . This can be seen by expanding
in the condition for a Lagrangian submanifold . This is that the symplectic form must vanish on the tangent manifold ; that is, it must vanish for all tangent vectors:
for all . Simplify the result by making use of the canonical symplectic form on :
and all others vanishing.
As local charts on a symplectic manifold take on the canonical form, this example suggests that Lagrangian submanifolds are relatively unconstrained. The classification of symplectic manifolds is done via Floer homology—this is an application of Morse theory to the action functional for maps between Lagrangian submanifolds. In physics, the action describes the time evolution of a physical system; here, it can be taken as the description of the dynamics of branes.
Example: Morse theory
Another useful class of Lagrangian submanifolds occur in Morse theory. Given a Morse function and for a small enough one can construct a Lagrangian submanifold given by the vanishing locus . For a generic Morse function we have a Lagrangian intersection given by .
Special Lagrangian submanifolds
In the case of Kähler manifolds (or Calabi–Yau manifolds) we can make a choice on as a holomorphic n-form, where is the real part and imaginary. A Lagrangian submanifold is called special if in addition to the above Lagrangian condition the restriction to is vanishing. In other words, the real part restricted on leads the volume form on . The following examples are known as special Lagrangian submanifolds,
complex Lagrangian submanifolds of hyperkähler manifolds,
fixed points of a real structure of Calabi–Yau manifolds.
The SYZ conjecture deals with the study of special Lagrangian submanifolds in mirror symmetry; see .
The Thomas–Yau conjecture predicts that the existence of a special Lagrangian submanifolds on Calabi–Yau manifolds in Hamiltonian isotopy classes of Lagrangians is equivalent to stability with respect to a stability condition on the Fukaya category of the manifold.
Lagrangian fibration
A Lagrangian fibration of a symplectic manifold M is a fibration where all of the fibres are Lagrangian submanifolds. Since M is even-dimensional we can take local coordinates and by Darboux's theorem the symplectic form ω can be, at least locally, written as , where d denotes the exterior derivative and ∧ denotes the exterior product. This form is called the Poincaré two-form or the canonical two-form. Using this set-up we can locally think of M as being the cotangent bundle and the Lagrangian fibration as the trivial fibration This is the canonical picture.
Lagrangian mapping
Let L be a Lagrangian submanifold of a symplectic manifold (K,ω) given by an immersion (i is called a Lagrangian immersion). Let give a Lagrangian fibration of K. The composite is a Lagrangian mapping. The critical value set of π ∘ i is called a caustic.
Two Lagrangian maps and are called Lagrangian equivalent if there exist diffeomorphisms σ, τ and ν such that both sides of the diagram given on the right commute, and τ preserves the symplectic form. Symbolically:
where τ∗ω2 denotes the pull back of ω2 by τ.
Special cases and generalizations
A symplectic manifold is exact if the symplectic form is exact. For example, the cotangent bundle of a smooth manifold is an exact symplectic manifold if we use the canonical symplectic form. The area 2-form on the 2-sphere is a symplectic form that is not exact.
A symplectic manifold endowed with a metric that is compatible with the symplectic form is an almost Kähler manifold in the sense that the tangent bundle has an almost complex structure, but this need not be integrable.
Symplectic manifolds are special cases of a Poisson manifold.
A multisymplectic manifold of degree k is a manifold equipped with a closed nondegenerate k-form.
A polysymplectic manifold is a Legendre bundle provided with a polysymplectic tangent-valued -form; it is utilized in Hamiltonian field theory.
See also
—an odd-dimensional counterpart of the symplectic manifold.
Citations
General and cited references
Further reading
Differential topology
Hamiltonian mechanics
Smooth manifolds
Symplectic geometry | Symplectic manifold | Physics,Mathematics | 2,519 |
50,520,262 | https://en.wikipedia.org/wiki/Mosaic%20protein | A mosaic protein is a protein that is made up of different protein domains, giving the protein multiple functions. These proteins have quaternary structures, as they are made up of multiple tertiary structured protein domains. Protein domains can combine to form different types of proteins, creating a diversity of proteins. These domains are spread throughout the genome because they are mobile, which is why some domains can be found in a variety of proteins, even though they are seemingly unrelated. This also allows the domains to fold independently, and so they don't become deformed and unfolded in a new environment.
Whereas many proteins are encoded by a single gene, many others get peptide chains from several genes; it is the nature of mosaic proteins that they are always polygenic.
Development
All proteins are transcribed and produced from blueprints in the cell, called genes. Mosaic proteins can be made when two adjacent genes are transcribed together and are therefore made into the same protein. This can benefit the protein because it makes the protein more stable and gives the protein a more complex function. For example, if the protein is an enzyme, it will be able to act more efficiently with its substrates.
Additionally, these proteins are most utilized outside of the cell membrane or on the outer side of membrane proteins. This suggests that these multifunctional proteins played a part in the development of multicellular organisms.
Examples
There are many studies comparing different mosaic proteins and their functional domains, trying to understand protein families and the overall functions of different proteins. For example, SpCRL and SpCRS proteins in sea urchins have a variety of functional domains that are also found within other proteins in the animal. By making comparisons, scientists can understand the complex roles these proteins play. Also, scientists are using the concept of mosaic proteins to improve vaccine function. Vaccines are injections of weak germ cells into the body that stimulate the body to produce antibodies specific to that germ. This ensures that the body will build an immunity, and that next time the germ is introduced, it will be more equipped to fight it off. Mosaic proteins of the germs can be designed in order to maximize antibody production and quality.
See also
Fluid mosaic model
References
External links
http://www.hiv.lanl.gov/content/sequence/MOSAIC/mosaic_explanation.html
http://www.nature.com/icb/journal/v71/n3/abs/icb199324a.html
Proteins | Mosaic protein | Chemistry | 504 |
14,135,865 | https://en.wikipedia.org/wiki/Earthflow | An earthflow (earth flow) is a downslope viscous flow of fine-grained materials that have been saturated with water and moves under the pull of gravity. It is an intermediate type of mass wasting that is between downhill creep and mudflow. The types of materials that are susceptible to earthflows are clay, fine sand and silt, and fine-grained pyroclastic material.
When the ground materials become saturated with enough water, they will start flowing (soil liquefaction). Its speed can range from being barely noticeable to rapid movement. The velocity of the flow is dictated by water content: the higher the water content is, the higher the velocity will be. Because of the dependency on water content for the velocity of the flow, it can take minutes or years for the materials to move down the slope.
Features and behavior
Earthflows are just one type of mass movement that can occur on a hill slope. It has been recognized as its own type of movement since the early 20th century. Earthflows are one of the most fluid types of mass movements. Earthflows occur on heavily saturated slopes like mudflows or a debris flow. Though earthflows are a lot like mudflows, overall they are slower and are covered with solid material carried along by flow from within. Earthflows are often made up of fine-grained materials so slopes consisting of clay and silt materials are more likely to create an earthflow.
As earthflows are usually water-dependent, the risk of one occurring is much higher in humid areas especially after a period of heavy rainfall or snowmelt. The high level of precipitation, which saturates the ground and adds water to the slope content, increases the pore-water pressure and reduces the shearing strength of the material. As the slope becomes wet, the earthflow may start as a creep downslope due to the clay or silt having less friction. As the material is increasingly more saturated, the slope will fail, which depends on slope stability. In earthflows, the slope does not fail along a clear shear plane and is instead more fluid as the material begins to move under the force of gravity as friction and slope stability is reduced.
Velocity
Earthflows vary in velocity of flow depending partly on the consistency of the flow for the speed of the entire movement, usually meaning how much water is in the material of the hill slope before the slope fails. Though water is often the key factor in slope failure, triggering an earthflow, there can also be dry granular flows made up of granular material. The speed also depends on the angle of slope as earthflows can happen on moderate or steep slopes. Because earthflows are usually water-dependent, they can take many years or just minutes to move a significant amount. An earthflow may affect as few as several square meters or up to several hectares in either time frame.
Effects
Earthflows can have sudden impacts on the amount of sediment that is deposited into a river system, which can have effects on the life in and around the river itself. They can also cause damage to roads and constructions built near the slope. One of the best mitigation techniques to avoid serious earthflow and landslide damage is properly draining the slope of water, especially in places of high levels of precipitation.
Areas of risk
The areas most at risk for earthflows are:
Slopes that have been undercut or loaded with more sediment for human construction
Slopes that have been undercut by rivers or stream beds
Areas that receive heavy rainfall or snowmelt
Hill slopes made up of clay, silt, or other fine-grained materials
Areas with limited vegetation on hill slopes
Areas with evidence of past earthflows
See also
Landslide mitigation
References
External links
Slumgullion earthflow, USGS Bulletin 2130, a National Natural Landmark in Colorado, USA.
New landslide video: a fascinating and huge Russian earthflow - American Geophysical Union, 17 April 2015
Geological hazards
Soil mechanics | Earthflow | Physics | 814 |
40,306,862 | https://en.wikipedia.org/wiki/Susan%20Shaw%20%28conservationist%29 | Susan D. Shaw (October 24, 1943 – January 27, 2022) was an American environmental health scientist, marine toxicologist, explorer, ocean conservationist, and author. A Doctor of Public Health, she was a professor in the Department of Environmental Health Sciences at the School of Public Health at the State University of New York at Albany, and Founder/President of the Shaw Institute, a nonprofit scientific institution with a mission to improve human and ecological health through innovative science and strategic partnerships. Shaw is globally recognized for pioneering high-impact environmental research on ocean pollution, climate change, oil spills, and plastics that has fueled public policy over three decades. In 1983, with landscape photographer Ansel Adams, she published Overexposure, the first book to document the health hazards of photographic chemicals. Shaw is credited as the first scientist to show that brominated flame retardant chemicals used in consumer products have contaminated marine mammals and commercially important fish stocks in the northwest Atlantic Ocean. She became the first scientist to dive into the Gulf of Mexico oil slick following the 2010 BP Deepwater Horizon oil rig explosion to investigate the impacts of chemical dispersants used in response to the spill.
Recognized as an outspoken voice on emerging contaminants like plastic, Shaw traveled globally to raise awareness on toxic legacy of man-made chemicals and its impact on public health and the environment.
Education and early career
Shaw was born in Dallas, Texas, the daughter of Edward Carrington and Lois (née Bonner) Shaw.
She received a Bachelor of Arts degree from the University of Texas in 1967 with a major in Plan II, an interdisciplinary honors program modeled after the Harvard Society of Fellows Program. She was selected for the UT-Chilean Exchange Program in 1964, and spent a year in Chile as a Fulbright Scholar. Shaw earned two degrees from Columbia University: an MFA degree in Film in 1970, and a doctorate in Public Health/Environmental Health Sciences (Dr.P.H.) in 1999.
In 1980, Ansel Adams commissioned her to write Overexposure, published in 1983 as the first book to document the health hazards of photographic chemicals used in the darkroom. A second edition of the book was published in 1991.
Shaw founded the Shaw Institute in Blue Hill, Maine in 1990 following the deaths of 20,000 harbor seals inhabiting polluted waters of northwestern Europe. This wildlife “signal” event was followed by other mass die-offs of marine mammals in polluted marine regions.
Advancing understanding of the impacts of toxic chemicals on marine mammal health became the Institute's research focus over the next two decades. In the Institute's mission to "discover and expose environmental threats to people and wildlife through innovative science," its focus areas are human exposure, plastics and microplastics, marine wildlife exposure, oil spill response, and Maine coastal monitoring.
Research
For three decades, Shaw's work focused on the health effects of environmental chemical exposure in marine wildlife and humans.
In 2000, the Shaw Institute began its long-term research focused on marine sentinel species to characterize the extent of contamination of the northwest Atlantic marine ecosystem from Maine to New York. Funded by the National Oceanic and Atmospheric Administration (NOAA), this region-wide effort has produced a large body of data on a wide range of persistent organic pollutants, including flame retardants, in marine mammals and fish that has placed the region in a global perspective. This work has shown that levels of toxic chemicals, such as polychlorinated biphenyls (PCBs), in northwest Atlantic harbor seals are among the highest in the world.
In 2007, Shaw was credited as the first scientist to show that brominated flame retardant chemicals used in household and consumer products have contaminated marine mammals and fish in the northwest Atlantic Ocean. This information helped support toxics policy reform in the state of Maine when the Legislature banned Deca-BDE from household products as of 2010.
That same year, Shaw was lead author on a review paper entitled Halogenated Flame Retardants: Do the Fire Safety Benefits Justify the Risks?, which challenged the efficacy of these chemicals in preventing fire deaths. It presented a large body of scientific evidence of the negative health effects, including cancer, that are associated with exposure to halogenated flame retardants in consumer products.
The paper had national policy implications, laying the groundwork for the San Antonio Statement, which cited the need for regulatory action on halogenated flame retardant chemicals worldwide. It was signed by more than 300 scientists from 30 countries. Shaw's paper and the statement were, in turn, the basis for the Chicago Tribune's 2012 exposé of the chemical industry's campaign to market harmful flame retardant chemicals to the American public.
BP Oil Spill
In May 2010, a month after the explosion of the Deepwater Horizon oil rig in the Gulf of Mexico, Shaw dove into the oil slick to investigate the impact of the chemical dispersant Corexit, which was being used to contain the oil spill. Her findings informed the national debate on the dangers of chemical dispersant use. She maintained that the dispersant-oil mixture was more toxic to wildlife and human health than the oil alone, because of the increased exposure to hydrocarbons in the water column, and the synergistic toxicity of Corexit and oil components combined.
Shaw was appointed to the Strategic Sciences Working Group (SSWG), convened by the US Department of the Interior, to assess the consequences of the oil spill and make policy recommendations to federal agencies. In September 2010, she drafted a scientific memo titled “It’s Not About Dose” on behalf of the SSWG stating there is no safe level of exposure to cancer-causing hydrocarbons in oil. The memo warned that the use of Corexit dispersants, in combination with crude oil, would result in long-term damage to wildlife and human health in the Gulf region. The Shaw Institute subsequently launched Gulf EcoTox, an independent investigation into the effects of oil and chemical dispersants in the food web.
Shaw predicted the decimation of deep-water coral, species known to be sensitive to the Corexit-oil mixture, and the deaths of dolphins from unavoidable inhalation of the mixture as they surfaced to breathe. Both outcomes have since occurred. She also predicted with certainty the human health crisis in the Gulf today, stating that a scientific review found that “five of the Corexit ingredients are linked to cancer, 33 are associated with skin irritation from rashes to burns, 33 are linked to eye irritation, 11 are or are suspected of being potential respiratory toxins or irritants, and 10 are suspected kidney toxins.”
She delivered three TEDx talks discussing the long-term damage to the ecosystem and the impending human health crisis in the Gulf as a result of exposure to the oil-Corexit mixture. She appeared in documentary films on the oil spill, including Animal Planet's Black Tide: Voices of the Gulf and Green Planet's The Big Fix.
Later work
The Shaw Institute's research examines the sources, fate, exposure pathways, tissue-specific bioaccumulation/biomagnification, and health effects of organic halogenated chemicals and other toxic man-made chemicals in the environment. The organization's current work focuses on highly exposed populations, including firefighters, to indoor contaminants including flame retardants and carcinogenic combustion by-products that may relate to their elevated rates of cancer. An expert on marine pollution, Shaw led a multinational project with scientists from Sweden, Greenland and Iceland to assess the converging impacts of climate change and flame retardant chemicals on marine mammals from the US Atlantic, Baltic, and Arctic seas.
In 2013, Shaw was lead investigator of a study that tested a group of firefighters in San Francisco and found that their blood contains high levels of flame retardants and cancer-causing chemicals such as dioxins and furans, produced by the burning of flame-retarded household materials. The study's findings suggested that chemical exposure during firefighting may carry higher risk for multiple cancers than previously demonstrated. Based on these findings, in 2014, the Institute announced plans for a long-term study of chemical exposure and cancer risk in U.S. firefighters.
In 2012 Shaw launched a study into microplastics in the Gulf of Maine that influenced a nationwide ban of microbeads in cosmetics. Shaw Institute scientists led a 2018 study on the uptake and expulsion of microplastic fibers by blue mussels (Mytilus edulis) in the Gulf of Maine. In 2018, the Shaw Institute partnered with the international Plastics Health Coalition in order to advance understanding of the damaging effects of microplastics in the human body and to promote plastic reduction across multiple sectors on a global scale. Shaw's final work was to draw attention to the health hazards faced by children employed as waste pickers and e-waste recyclers.
Honors and awards
Shaw was a Woodrow Wilson Visiting Fellow to U.S. universities and was named a Gulf of Maine Visionary by the Gulf of Maine Council on the Marine Environment in 2007. In May 2011, she became the 19th recipient of the Society of Woman Geographers' Gold Medal Award dating back to 1933, when Amelia Earhart became its first recipient. In March 2012, Shaw received the Explorers Club Citation of Merit Award for her work in ocean conservation. In 2011, she was named “Woman of the Gulf” by Audubon Society Women in Conservation at the Rachel Carson Awards. She was a recipient of the 2012 Next Award from Mainebiz magazine for her work in shaping the future and the economy of Maine. On Earth Day 2019, Shaw was named one of the "Top Eco-Warrior Women in the World" by Make it Better magazine.
Personal life
Shaw met artist Cynthia Stroud, her future wife, in 1980 in New York City. They moved to Brooklin, Maine, where they lived for several decades. They played pétanque competitively, including a second-place finish at the 2012 Federation Petanque USA Women's World Qualifier. They moved back to New York City, where Shaw died on January 27, 2022, at the age of 78.
References
External links
1943 births
2022 deaths
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Writers from Dallas | Susan Shaw (conservationist) | Chemistry,Environmental_science | 2,209 |
2,997,610 | https://en.wikipedia.org/wiki/Bauer%E2%80%93Fike%20theorem | In mathematics, the Bauer–Fike theorem is a standard result in the perturbation theory of the eigenvalue of a complex-valued diagonalizable matrix. In its substance, it states an absolute upper bound for the deviation of one perturbed matrix eigenvalue from a properly chosen eigenvalue of the exact matrix. Informally speaking, what it says is that the sensitivity of the eigenvalues is estimated by the condition number of the matrix of eigenvectors.
The theorem was proved by Friedrich L. Bauer and C. T. Fike in 1960.
The setup
In what follows we assume that:
is a diagonalizable matrix;
is the non-singular eigenvector matrix such that , where is a diagonal matrix.
If is invertible, its condition number in -norm is denoted by and defined by:
The Bauer–Fike Theorem
Bauer–Fike Theorem. Let be an eigenvalue of . Then there exists such that:
Proof. We can suppose , otherwise take and the result is trivially true since . Since is an eigenvalue of , we have and so
However our assumption, , implies that: and therefore we can write:
This reveals to be an eigenvalue of
Since all -norms are consistent matrix norms we have where is an eigenvalue of . In this instance this gives us:
But is a diagonal matrix, the -norm of which is easily computed:
whence:
An Alternate Formulation
The theorem can also be reformulated to better suit numerical methods. In fact, dealing with real eigensystem problems, one often has an exact matrix , but knows only an approximate eigenvalue-eigenvector couple, and needs to bound the error. The following version comes in help.
Bauer–Fike Theorem (Alternate Formulation). Let be an approximate eigenvalue-eigenvector couple, and . Then there exists such that:
Proof. We can suppose , otherwise take and the result is trivially true since . So exists, so we can write:
since is diagonalizable; taking the -norm of both sides, we obtain:
However
is a diagonal matrix and its -norm is easily computed:
whence:
A Relative Bound
Both formulations of Bauer–Fike theorem yield an absolute bound. The following corollary is useful whenever a relative bound is needed:
Corollary. Suppose is invertible and that is an eigenvalue of . Then there exists such that:
Note. can be formally viewed as the relative variation of , just as is the relative variation of .
Proof. Since is an eigenvalue of and , by multiplying by from left we have:
If we set:
then we have:
which means that is an eigenvalue of , with as an eigenvector. Now, the eigenvalues of are , while it has the same eigenvector matrix as . Applying the Bauer–Fike theorem to with eigenvalue , gives us:
The Case of Normal Matrices
If is normal, is a unitary matrix, therefore:
so that . The Bauer–Fike theorem then becomes:
Or in alternate formulation:
which obviously remains true if is a Hermitian matrix. In this case, however, a much stronger result holds, known as the Weyl's theorem on eigenvalues. In the hermitian case one can also restate the Bauer–Fike theorem in the form that the map that maps a matrix to its spectrum is a non-expansive function with respect to the Hausdorff distance on the set of compact subsets of .
References
Spectral theory
Theorems in analysis
Articles containing proofs | Bauer–Fike theorem | Mathematics | 756 |
20,756,012 | https://en.wikipedia.org/wiki/Rayleigh%20wave | Rayleigh waves are a type of surface acoustic wave that travel along the surface of solids. They can be produced in materials in many ways, such as by a localized impact or by piezo-electric transduction, and are frequently used in non-destructive testing for detecting defects. Rayleigh waves are part of the seismic waves that are produced on the Earth by earthquakes. When guided in layers they are referred to as Lamb waves, Rayleigh–Lamb waves, or generalized Rayleigh waves.
Characteristics
Rayleigh waves are a type of surface wave that travel near the surface of solids. Rayleigh waves include both longitudinal and transverse motions that decrease exponentially in amplitude as distance from the surface increases. There is a phase difference between these component motions.
The existence of Rayleigh waves was predicted in 1885 by Lord Rayleigh, after whom they were named. In isotropic solids these waves cause the surface particles to move in ellipses in planes normal to the surface and parallel to the direction of propagation – the major axis of the ellipse is vertical. At the surface and at shallow depths this motion is retrograde, that is the in-plane motion of a particle is counterclockwise when the wave travels from left to right. At greater depths the particle motion becomes prograde. In addition, the motion amplitude decays and the eccentricity changes as the depth into the material increases. The depth of significant displacement in the solid is approximately equal to the acoustic wavelength. Rayleigh waves are distinct from other types of surface or guided acoustic waves such as Love waves or Lamb waves, both being types of guided waves supported by a layer, or longitudinal and shear waves, that travel in the bulk.
Rayleigh waves have a speed slightly less than shear waves by a factor dependent on the elastic constants of the material. The typical speed of Rayleigh waves in metals is of the order of 2–5 km/s, and the typical Rayleigh speed in the ground is of the order of 50–300 m/s for shallow waves less than 100-m depth and 1.5–4 km/s at depths greater than 1 km. Since Rayleigh waves are confined near the surface, their in-plane amplitude when generated by a point source decays only as , where is the radial distance. Surface waves therefore decay more slowly with distance than do bulk waves, which spread out in three dimensions from a point source. This slow decay is one reason why they are of particular interest to seismologists. Rayleigh waves can circle the globe multiple times after a large earthquake and still be measurably large. There is a difference in the behavior (Rayleigh wave velocity, displacements, trajectories of the particle motion, stresses) of Rayleigh surface waves with positive and negative Poisson's ratio.
In seismology, Rayleigh waves (called "ground roll") are the most important type of surface wave, and can be produced (apart from earthquakes), for example, by ocean waves, by explosions, by railway trains and ground vehicles, or by a sledgehammer impact.
Speed and dispersion
In isotropic, linear elastic materials described by Lamé parameters and , Rayleigh waves have a speed given by solutions to the equation
where , , , and .
Since this equation has no inherent scale, the boundary value problem giving rise to Rayleigh waves are dispersionless.
An interesting special case is the Poisson solid, for which , since this gives a frequency-independent phase velocity equal to . For linear elastic materials with positive Poisson ratio (), the Rayleigh wave speed can be approximated as , where is the shear-wave velocity.
The elastic constants often change with depth, due to the changing properties of the material. This means that the velocity of a Rayleigh wave in practice becomes dependent on the wavelength (and therefore frequency), a phenomenon referred to as dispersion. Waves affected by dispersion have a different wave train shape. Rayleigh waves on ideal, homogeneous and flat elastic solids show no dispersion, as stated above. However, if a solid or structure has a density or sound velocity that varies with depth, Rayleigh waves become dispersive. One example is Rayleigh waves on the Earth's surface: those waves with a higher frequency travel more slowly than those with a lower frequency. This occurs because a Rayleigh wave of lower frequency has a relatively long wavelength. The displacement of long wavelength waves penetrates more deeply into the Earth than short wavelength waves. Since the speed of waves in the Earth increases with increasing depth, the longer wavelength (low frequency) waves can travel faster than the shorter wavelength (high frequency) waves. Rayleigh waves thus often appear spread out on seismograms recorded at distant earthquake recording stations. It is also possible to observe Rayleigh wave dispersion in thin films or multi-layered structures.
In non-destructive testing
Rayleigh waves are widely used for materials characterization, to discover the mechanical and structural properties of the object being tested – like the presence of cracking, and the related shear modulus. This is in common with other types of surface waves. The Rayleigh waves used for this purpose are in the ultrasonic frequency range.
They are used at different length scales because they are easily generated and detected on the free surface of solid objects. Since they are confined in the vicinity of the free surface within a depth (~ the wavelength) linked to the frequency of the wave, different frequencies can be used for characterization at different length scales.
In electronic devices
Rayleigh waves propagating at high ultrasonic frequencies (10–1000 MHz) are used widely in different electronic devices. In addition to Rayleigh waves, some other types of surface acoustic waves (SAW), e.g. Love waves, are also used for this purpose. Examples of electronic devices using Rayleigh waves are filters, resonators, oscillators, sensors of pressure, temperature, humidity, etc. Operation of SAW devices is based on the transformation of the initial electric signal into a surface wave that, after achieving the required changes to the spectrum of the initial electric signal as a result of its interaction with different types of surface inhomogeneity, is transformed back into a modified electric signal. The transformation of the initial electric energy into mechanical energy (in the form of SAW) and back is usually accomplished via the use of piezoelectric materials for both generation and reception of Rayleigh waves as well as for their propagation.
In geophysics
Generation from earthquakes
Because Rayleigh waves are surface waves, the amplitude of such waves generated by an earthquake generally decreases exponentially with the depth of the hypocenter (focus). However, large earthquakes may generate Rayleigh waves that travel around the Earth several times before dissipating.
In seismology longitudinal and shear waves are known as P waves and S waves, respectively, and are termed body waves. Rayleigh waves are generated by the interaction of P- and S- waves at the surface of the earth, and travel with a velocity that is lower than the P-, S-, and Love wave velocities. Rayleigh waves emanating outward from the epicenter of an earthquake travel along the surface of the earth at about 10 times the speed of sound in air (0.340 km/s), that is ~3 km/s.
Due to their higher speed, the P and S waves generated by an earthquake arrive before the surface waves. However, the particle motion of surface waves is larger than that of body waves, so the surface waves tend to cause more damage. In the case of Rayleigh waves, the motion is of a rolling nature, similar to an ocean surface wave. The intensity of Rayleigh wave shaking at a particular location is dependent on several factors:
The size of the earthquake.
The distance to the earthquake.
The depth of the earthquake.
The geologic structure of the crust.
The focal mechanism of the earthquake.
The rupture directivity of the earthquake.
Local geologic structure can serve to focus or defocus Rayleigh waves, leading to significant differences in shaking over short distances.
In seismology
Low frequency Rayleigh waves generated during earthquakes are used in seismology to characterise the Earth's interior.
In intermediate ranges, Rayleigh waves are used in geophysics and geotechnical engineering for the characterisation of oil deposits. These applications are based on the geometric dispersion of Rayleigh waves and on the solution of an inverse problem on the basis of seismic data collected on the ground surface using active sources (falling weights, hammers or small explosions, for example) or by recording microtremors.
Rayleigh ground waves are important also for environmental noise and vibration control since they make a major contribution to traffic-induced ground vibrations and the associated structure-borne noise in buildings.
Possible animal reaction
Low frequency (< 20 Hz) Rayleigh waves are inaudible, yet they can be detected by many mammals, birds, insects and spiders. Humans should be able to detect such Rayleigh waves through their Pacinian corpuscles, which are in the joints, although people do not seem to consciously respond to the signals. Some animals seem to use Rayleigh waves to communicate. In particular, some biologists theorize that elephants may use vocalizations to generate Rayleigh waves. Since Rayleigh waves decay slowly, they should be detectable over long distances. Note that these Rayleigh waves have a much higher frequency than Rayleigh waves generated by earthquakes.
After the 2004 Indian Ocean earthquake, some people have speculated that Rayleigh waves served as a warning to animals to seek higher ground, allowing them to escape the more slowly traveling tsunami. At this time, evidence for this is mostly anecdotal. Other animal early warning systems may rely on an ability to sense infrasonic waves traveling through the air.
See also
Linear elasticity
Longitudinal wave
Love wave
Phonon
Surface acoustic wave
References
Further reading
Viktorov, I.A. (2013) "Rayleigh and Lamb Waves: Physical Theory and Applications", Springer; Reprint of the original 1st 1967 edition by Plenum Press, New York. .
Aki, K. and Richards, P. G. (2002). Quantitative Seismology (2nd ed.). University Science Books. .
Fowler, C. M. R. (1990). The Solid Earth. Cambridge, UK: Cambridge University Press. .
Lai, C.G., Wilmanski, K. (Eds.) (2005). Surface Waves in Geomechanics: Direct and Inverse Modelling for Soils and Rocks Series: CISM International Centre for Mechanical Sciences, Number 481, Springer, Wien,
External links
Real-time imaging of Rayleigh waves
Acoustics
Seismology
Surface waves
Waves | Rayleigh wave | Physics | 2,192 |
33,594,755 | https://en.wikipedia.org/wiki/Blakers%E2%80%93Massey%20theorem | In mathematics, the first Blakers–Massey theorem, named after Albert Blakers and William S. Massey, gave vanishing conditions for certain triad homotopy groups of spaces.
Description of the result
This connectivity result may be expressed more precisely, as follows. Suppose X is a topological space which is the pushout of the diagram
,
where f is an m-connected map and g is n-connected. Then the map of pairs
induces an isomorphism in relative homotopy groups in degrees and a surjection in the next degree.
However the third paper of Blakers and Massey in this area determines the critical, i.e., first non-zero, triad homotopy group as a tensor product, under a number of assumptions, including some simple connectivity. This condition and some dimension conditions were relaxed in work of Ronald Brown and Jean-Louis Loday. The algebraic result implies the connectivity result, since a tensor product is zero if one of the factors is zero. In the non simply connected case, one has to use the nonabelian tensor product of Brown and Loday.
The triad connectivity result can be expressed in a number of other ways, for example, it says that the pushout square above behaves like a homotopy pullback up to dimension .
Generalization to higher toposes
The generalization of the connectivity part of the theorem from traditional homotopy theory to any other infinity-topos with an infinity-site of definition was given by Charles Rezk in 2010.
Fully formal proof
In 2013 a fairly short, fully formal proof using homotopy type theory as a mathematical foundation and an Agda variant as a proof assistant was announced by Peter LeFanu Lumsdaine; this became Theorem 8.10.2 of Homotopy Type Theory – Univalent Foundations of Mathematics. This induces an internal proof for any infinity-topos (i.e. without reference to a site of definition); in particular, it gives a new proof of the original result.
References
External links
Theorem 6.4.1
Theorems in algebraic topology | Blakers–Massey theorem | Mathematics | 425 |
46,288,668 | https://en.wikipedia.org/wiki/Infill%20wall | The infill wall is the supported wall that closes the perimeter of a building constructed with a three-dimensional framework structure (generally made of steel or reinforced concrete). Therefore, the structural frame ensures the bearing function, whereas the infill wall serves to separate inner and outer space, filling up the boxes of the outer frames. The infill wall has the unique static function to bear its own weight. The infill wall is an external vertical opaque type of closure. With respect to other categories of wall, the infill wall differs from the partition that serves to separate two interior spaces, yet also non-load bearing, and from the load bearing wall. The latter performs the same functions of the infill wall, hygro-thermically and acoustically, but performs static functions too.
The use of masonry infill walls, and to some extent veneer walls, especially in reinforced concrete frame structures, is common in many countries. In fact, the use of masonry infill walls offers an economical and durable solution. They are easy to build, attractive for architecture and have a very efficient cost-performance.
Today, masonry enclosures and partition walls are mainly made of clay units, but also aggregate concrete units (dense and lightweight aggregate) and autoclaved aerated concrete units are used. More recently, industry is also trying to introduce wood concrete blocks. Partition walls, made with both vertically and horizontally perforated clay blocks, represent two-thirds of the corresponding market.
Requirements for enclosure systems
Masonry enclosure walls systems, must meet some structural and non-structural requirements.
Structural
The requirements relating structural stability are currently defined and regulated by Eurocode 6 for load bearing masonry structures and by Eurocode 8 for seismic safety. These codes impose requirements for masonry walls, particularly non-collapse (in-plane/out of plane) and damage limitation, providing methods of calculation to ensure these two requirements.
Some of the non-structural requirements are: fire safety, thermal comfort, acoustic comfort, durability and water leakage.
Fire safety
The safety against fire is one of the requirements that is often required to enclosures walls. However, as usually the more traditionally used materials (blocks, bricks and mortar) are not fuel products, it is relatively easy to achieve the requirements relating to the limitation of spread of fire, thermal insulation and structural strength, which in severe cases, must be guaranteed for 180 minutes.
Thermal comfort
The thermal comfort is a requirement with which the enclosure walls must comply. This requirement has a direct influence on the construction of the walls. The thermal regulations are demanding increasingly higher values of thermal resistance to the walls. To meet these demands new products and building systems, which ensure that the thermal resistances requested by the regulations will be provided, are developed. It is likely that in the near future traditional construction solutions with double leaf walls (with new, more thermally efficient bricks and blocks) will be adapted, and there will be increased use of thermal insulation systems for exterior (ETICS), such as use of single leaf walls. Also the use of insulation systems from the inside will increase. The development of new enclosure wall systems should, apart from trying to improve requisites relating to structural stability in case of earthquake, improve the thermal resistance of the solution.
Durability and waterproofing
To ensure durability and waterproofing, the most important thing is to avoid errors in design and construction, leading to the appearance of (structural and non-structural) pathologies. Some requisites that the walls must have in order to avoid pathologies are: adequate expansion joints, correct support of the walls in the correction of thermal bridges, appropriate clipping between masonry leafs, correct implementation of space between leafs, proper placement of thermal insulation. The proper use of paints, protection against moisture and the correct preparation and application of traditional plasters, among others, are important factors
Interaction between buildings and masonry infills
Global behaviour
When there is the perimeter contact between the masonry infill walls and the frame, in ordinary situations of adherent robust infill walls, the effect of stiffness increase (and also dissipation) influences the building response. In the case of infill walls built disconnected from the structure (not in adherence with the frame elements), it is likely that infill walls act as an additional mass applied to the structure only, and should not have other significant effects.
In general, in the most frequent case of perimeter contact between the masonry panels and the beams and columns of the RC structure, the infill panels interact with the structure, regardless of the lateral resistance capacity of the structure, and act like structural elements, overtaking lateral loads until they are badly damaged or destroyed. In this case, the most important effects of the structure-infill interaction are:
Increased lateral rigidity of the structure; in the case of flexible structures from seismic zones with small values of the period Tc, the seismic forces increase over the normal level;
Creating some vertical irregularities by increasing the ductility demand at one storey, or creating some horizontal irregularities by increasing the ensemble torsion as a result of modifying the centre of rigidity; for the design of buildings in seismic zones, these situations must be always avoided;
Creating some solicitations of short elements type, having a risk of rupture to shear force, due to the fact that on the deformable zone of the column the shear force is substantially larger than in the normal case (also treated as local effect).
Local behavior
The main problems in the local interaction between frame and infill are the formation of short beam, short column effect in the structural elements. The zones in which supplementary shear forces can occur, acting locally on the extremities of the beams and columns, should be dimensioned and transversally reinforced in order to overtake safely these forces.
Infill wall types
Single-leaf wall
A wall without a cavity or continuous vertical joint in its plane.
Cavity wall
A wall consisting of two parallel single-leaf walls, effectively tied together with wall ties or bed joint reinforcement. The space between the leaves is left as a continuous cavity or filled or partially filled with non-loadbearing thermal insulating material. A wall consisting of two leaves separated by a cavity, where one of the leaves is not contributing to the strength or stiffness of the other (possibly loadbearing) leaf, is to be regarded as a veneer wall.
Veneer wall
A wall used as a facing but not bonded or contributing to the strength of the backing wall or framed structure.
References
External links
INSYSME
Structural engineering | Infill wall | Engineering | 1,347 |
12,836,195 | https://en.wikipedia.org/wiki/N-Methylphenethylamine | N-Methylphenethylamine (NMPEA) is a naturally occurring trace amine neuromodulator in humans that is derived from the trace amine, phenethylamine (PEA). It has been detected in human urine (<1 μg over 24 hours) and is produced by phenylethanolamine N-methyltransferase with phenethylamine as a substrate, which significantly increases PEA's effects. PEA breaks down into phenylacetaldehyde which is further broken down into phenylacetic acid by monoamine oxidase. When this is inhibited by monoamine oxidase inhibitors, it allows more of the PEA to be metabolized into nymphetamine (NMPEA) and not wasted on the weaker inactive metabolites.
PEA and NMPEA are both alkaloids that are found in a number of different plant species as well. Some Acacia species, such as A. rigidula, contain remarkably high levels of NMPEA (~2300–5300 ppm). NMPEA is also present at low concentrations (< 10 ppm) in a wide range of foodstuffs.
NMPEA is a positional isomer of amphetamine.
Biosynthesis
Chemistry
In appearance, NMPEA is a colorless liquid. NMPEA is a weak base, with pKa = 10.14; pKb = 3.86 (calculated from data given as Kb). It forms a hydrochloride salt, m.p. 162–164 °C.
Although NMPEA is available commercially, it may be synthesized by various methods. An early synthesis reported by Carothers and co-workers involved conversion of phenethylamine to its p-toluenesulfonamide, followed by N-methylation using methyl iodide, then hydrolysis of the sulfonamide. A more recent method, similar in principle, and used for making NMPEA radio-labeled with 14C in the N-methyl group, started with the conversion of phenethylamine to its trifluoroacetamide. This was N-methylated (in this particular case using 14C – labeled methyl iodide), and then the amide hydrolyzed.
NMPEA is a substrate for both MAO-A (KM = 58.8 μM) and MAO-B (KM = 4.13 μM) from rat brain mitochondria.
Pharmacology
NMPEA is a pressor, with 1/350 x the potency of epinephrine.
Like its parent compound, PEA, and isomer, amphetamine, NMPEA is a potent agonist of human trace amine-associated receptor 1 (hTAAR1). It has comparable pharmacodynamic and toxicodynamic properties to that of phenethylamine, amphetamine, and other methylphenethylamines in rats.
As with PEA, NMPEA is metabolized relatively rapidly by monoamine oxidases during first pass metabolism; both compounds are preferentially metabolized by MAO-B.
Toxicology
The "minimum lethal dose" (mouse, i.p.) of the HCl salt of NMPEA is 203 mg/kg; the LD50 for oral administration to mice of the same salt is 685 mg/kg.
Acute toxicity studies on NMPEA show an LD50 = 90 mg/kg, after intravenous administration to mice.
References
Phenethylamine alkaloids
TAAR1 agonists
Amphetamine
Trace amines
Phenethylamines
Norepinephrine-dopamine releasing agents
Amino acid derivatives
Secondary amines | N-Methylphenethylamine | Chemistry | 782 |
23,197,445 | https://en.wikipedia.org/wiki/John%20Murphy%20%28contractor%29 | John Murphy (5 October 1913 – 7 May 2009) was an Irish business man who established the construction and infrastructure contractor J. Murphy & Sons. The company, based in Kentish Town, with its green vans and lorries, works on building sites across the UK and Ireland. His late brother Joe also went into construction in London, trading as Murphy Ltd and using grey vehicles, but that company went into administration and closed in 2013.
Biography
Murphy was born at Loughmark, near Cahersiveen, County Kerry. He left school at 15 but found work hard to come by. He travelled to London and started up as a subcontractor in the building trade. The Second World War offered him a golden opportunity. New airfields were urgently needed and later on runway repairs were needed also. He was successful in providing this service and at end of the war was well placed to help with large-scale reconstruction. Other ventures included electrification, cable installation, water facilities and road-building.
At his death in 2009, his worth was estimated at £190 million. He valued his privacy and was known to spend little on luxuries, instead preferring to spend time with his own workmen and other Irish friends.
J Murphy & Sons
In the 1970s a specialist division of the company worked on the development of natural gas. Later projects included the Stansted Airport Rail Link, work in the City of London, the Channel Tunnel Rail Link and London's Olympic Park.
In 2007 J Murphy and Sons generated nearly £500 million of revenue and made pre-tax profits of £60 million. It was appointed lead contractor in the £125 million Liverpool-Manchester water pipeline project, which is to carry up to 100 million litres of water per day.
After Murphy's death in May 2009, leadership of the company passed initially to his daughter Caroline, who had been appointed deputy chairperson of the group in 2007. She later planned to turn the business into a worker's Co-op owned by its 3,500 employees, but other board members — notably her mother, brother and half-brother — resisted, and she resigned in 2014.
The company was then led by Steve Hollingshead until the appointment in 2017 of John Murphy's grandson, John B Murphy.
In the year to 31 December 2017 the company made a pre-tax profit of £12.43m from a turnover of £711m, and had 3,878 employees. In 2018, it experienced a slow down in growth, and cancelled its Christmas Party as part of a cost-cutting drive affecting jobs across the business.
References
1913 births
2009 deaths
People from Cahersiveen
Civil engineering contractors
20th-century Irish businesspeople | John Murphy (contractor) | Engineering | 544 |
982,231 | https://en.wikipedia.org/wiki/Rubble%20trench%20foundation | The rubble trench foundation, an ancient construction approach popularized by architect Frank Lloyd Wright, is a type of foundation that uses loose stone or rubble to minimize the use of concrete and improve drainage. It is considered more environmentally friendly than other types of foundation because cement manufacturing requires the use of enormous amounts of energy. However, some soil environments are not suitable for this kind of foundation, particularly expansive or poor load-bearing (< 1 ton/sf) soils. A rubble trench foundation with a concrete grade beam is not recommended for earthquake prone areas.
A foundation must bear the structural loads imposed upon it and allow proper drainage of ground water to prevent expansion or weakening of soils and frost heaving. While the far more common concrete foundation requires separate measures to ensure good soil drainage, the rubble trench foundation serves both foundation functions at once.
To construct a rubble trench foundation a narrow trench is dug down below the frost line. The bottom of the trench would ideally be gently sloped to an outlet. Drainage tile, graded 1":8' to daylight, is then placed at the bottom of the trench in a bed of washed stone protected by filter fabric. The trench is then filled with either screened stone (typically 1-1/2") or recycled rubble. A steel-reinforced concrete grade beam may be poured at the surface to provide ground clearance for the structure.
If an insulated slab is to be poured inside the grade beam, then the outer surface of the grade beam and the rubble trench should be insulated with rigid XPS foam board, which must be protected above grade from mechanical and UV degradation.
The rubble-trench foundation is a relatively simple, inexpensive, and environment-friendly alternative to a conventional foundation, but may require an engineer's approval if building officials are not familiar with it. Frank Lloyd Wright used them successfully for more than 50 years in the first half of the 20th century, and there is a revival of this style of foundation with the increased interest in green building.
References
Shallow foundations
Sustainable building
Civil engineering | Rubble trench foundation | Engineering | 404 |
23,191,617 | https://en.wikipedia.org/wiki/Link%20relation | A link relation is a descriptive attribute attached to a hyperlink in order to define the type of the link, or the relationship between the source and destination resources. The attribute can be used by automated systems, or can be presented to a user in a different way.
In HTML these are designated with the attribute on , , or elements. Example uses include the standard way of referencing CSS, , which indicates that the external resource linked to with the attribute is a stylesheet, so a web browser will generally fetch this file to render the page. Another example is for the popular favicon icon.
Link relations are used in some microformats (e.g. for tagging), in XHTML Friends Network (XFN), and in the Atom standard, in XLink, as well as in HTML. Standardized link relations are one of the foundations of HATEOAS as they allow the user agent to understand the meaning of the available state transitions in a Representational State Transfer system.
The Internet Engineering Task Force (IETF) has a registry of standardized link relations, and a procedure for extending it defined in RFC 5988. HTML5 also defines valid link relations.
In HTML4, the rev attribute of a link is also defined, which defines the relationship between the resources. The attribute is removed in HTML5.
Semantic Web implementation
The RDF typed links are fundamental in LOD datasets for identifying the relationship (predicate) type of RDF triples, contributing to the automatic processability of machine-readable statements of the Giant Global Graph on the Semantic Web. The typed links in RDF are expressed as the value of the rdf:type property, defining the relationship type using well-established controlled vocabulary terms or definitions from LOD datasets such as
<rdf:type rdf:resource="http://schema.org/Person" />
References
External links
rel values defined in HTML 4
rel values to be defined in HTML5
rel values which are defined in some specification
WHATWG blog entry on link relations
HTML | Link relation | Technology | 426 |
285,944 | https://en.wikipedia.org/wiki/Email%20art | Email art refers to artwork created for the medium of email. It includes computer graphics, animations, screensavers, digital scans of artwork in other media, and even ASCII art. When exhibited, Email art can be either displayed on a computer screen or similar type of display device, or the work can be printed out and displayed.
Email art is an evolution of the networking Mail Art movement and began during the early 1990s. Chuck Welch, also known as Cracker Jack Kid, connected with early online artists and created a net-worker telenetlink. The historical evolution of the term "Email art" is documented in Chuck Welch's Eternal Network: A Mail Art Anthology published and edited by University of Calgary Press.
By the end of the 1990s, many mailartists, aware of increasing postal rates and cheaper internet access, were beginning the gradual migration of collective art projects towards the web and new, inexpensive forms of digital communication. The Internet facilitated faster dissemination of Mail Art calls (invitations), Mail Art blogs and websites have become commonly used to display contributions and online documentation, and an increasing number of projects include an invitation to submit Email art digitally, either as the preferred channel or as an alternative to sending contributions by post.
In 2006, Ramzi Turki received an e-mail containing a scanned work of Belgian artist Luc Fierens, so he sent this picture to about 7000 e-mail addresses artists seeking their interactions in order to acquire about 200 contributions and answers.
See also
Cyberculture
Digital art
Fax art
Internet art
Mail art
References
Computer networking
Email
Internet art
New media art
Digital art | Email art | Technology,Engineering | 326 |
27,248,800 | https://en.wikipedia.org/wiki/Middlebrook%207H11%20Agar | Middlebrook 7H11 agar is identical to Middlebrook 7H10 agar, with an addition of pancreatic digest of casein to facilitate the growth of fastidious cultures of M. tuberculosis.
Mycobactin J may also be added to Middlebrook 7H11 agar to allow the recovery of M. genavense.
See also
Lowenstein-Jensen medium
Middlebrook 7H9 broth
References
External links
Middlebrook 7H11 Agar
Microbiological media | Middlebrook 7H11 Agar | Biology | 102 |
464,963 | https://en.wikipedia.org/wiki/One%20half | One half is the multiplicative inverse of 2. It is an irreducible fraction with a numerator of 1 and a denominator of 2. It often appears in mathematical equations, recipes and measurements.
As a word
One half is one of the few fractions which are commonly expressed in natural languages by suppletion rather than regular derivation. In English, for example, compare the compound "one half" with other regular formations like "one-sixth".
A half can also be said to be one part of something divided into two equal parts. It is acceptable to write one half as a hyphenated word, one-half.
Mathematics
One half is the rational number that lies midway between 0 and 1 on the number line. Multiplication by one half is equivalent to division by two, or "halving"; conversely, division by one half is equivalent to multiplication by two, or "doubling".
A number raised to the power of one half is equal to its square root.
The area of a triangle is one half its base and altitude (or height).
The gamma function evaluated at one half is the square root of pi.
It has two different decimal representations in base ten, the familiar and the recurring , with a similar pair of expansions in any even base; while in odd bases, one half has no terminating representation.
The Bernoulli number has the value (its sign depending on competing conventions).
The Riemann hypothesis is the conjecture that every nontrivial complex root of the Riemann zeta function has a real part equal to .
Computer characters
The "one-half" symbol has its own code point as a precomposed character in the Number Forms block of Unicode, rendering as .
The reduced size of this symbol may make it illegible to readers with relatively mild visual impairment; consequently the decomposed forms or may be more appropriate.
See also
Division by two
References
Half
Rational numbers | One half | Mathematics | 393 |
23,776,072 | https://en.wikipedia.org/wiki/Fast%20statistical%20alignment | Fast statistical alignment or FSA is a multiple sequence alignment program for aligning many proteins, RNAs, or long genomic DNA sequences. Along with MUSCLE and MAFFT, FSA is one of the few sequence alignment programs which can align datasets of hundreds or thousands of sequences. FSA uses a different optimization criterion which allows it to more reliably identify non-homologous sequences than these other programs, although this increased accuracy comes at the cost of decreased speed.
FSA is currently being used for multiple projects, including sequencing new worm genomes and analyzing in vivo transcription factor binding in flies.
Input/Output
This program accepts sequences in FASTA format and outputs alignments in FASTA format or Stockholm format.
Algorithm
The algorithm for the aligning of the input sequences has 4 core components.
Pair Hidden Markov Model for generating posterior probabilities
The algorithm starts first by determining posterior probabilities of alignment between any two random sequences from the pool of sequences being aligned. The posterior probabilities for each column reinforce the prediction of alignment probability between a sequence pair and also filter out columns that can be unreliably aligned. These probabilities also allow for the prediction and estimate of homology between any sequence pair. A standard five-state pair hidden Markov model (Pair HMM) is used to determine these posterior probabilities of alignment for any two input sequences. The Pair HMM model uses two sets of Delete (D) and Insert (I) states to account for symbol deletion and insertions between two aligned sequences, but it can also have three states without a significant loss of accuracy.
Since the number of pair-wise comparisons needed to determine the posterior probability distributions of any two pairs of sequences is computationally expensive and quadratic in the amount of sequences that are being aligned, it is decreased by using a randomized approach inspired by the Erdos-Renyi theory of random graphs. This significantly reduces the runtimes of datasets and the computational cost of running the multiple alignments.
Merging Probabilities
The posterior probabilities for each column in the sequence pairs are sorted using a weighting function that uses a steepest-ascent algorithm.
Sequence Annealing
Most existing programs that run multiple sequence alignment algorithms are based on progressive alignment where the process starts with a "null alignment," a state where none of the sequences have been aligned. The pool of sequences is then aligned either through pairwise comparisons or through an alignment of a pair of partial alignments of subsequences. This process can cause issues in alignment because the resulting multiple sequence alignment can and will heavily depend on the sequences that are aligned at the start. There is no realigning of previously aligned sequences that could correct the MSA.
FSA uses the sequence annealing technique to overcome this issue. The sorted posterior probabilities are used with the sequence annealing technique to generate a multiple alignment. The technique finds the alignment between two sequences that minimizes the expected distance to the truth. In this case, the distance between two sequences is the number of columns in which the character from one sequence is not homologous to the character in the same column in the second sequence.
The sequence annealing technique, by determining an alignment with the minimum expected distance to the truth, conversely finds the alignment with the maximum expected accuracy. The accuracy of an alignment depends on a "true" alignment as reference and indicates the fraction of columns where the sequences are homologous. This accuracy is then used as an objective function that starts with the unaligned sequences (null alignment) and aligns characters in different columns based on the increasing accuracy of an alignment.
Ordering of the alignment
FSA aligns multiple sequences based on homology within columns instead of strictly a consideration of indels and substitutions. As such, FSA considers alignments to be equivalent if for every position along the sequences in both alignments, the same statement about homology can be made. For example, when considering pairwise comparisons, if there is a gap at a specific position in two alignments, then it can be said that the two sequences being compared are not homologous at said position. This can result in alignments where gap-open events can differ and yet still be considered equivalent. As such, FSA chooses to output the alignment in which there is a minimum amount of "gap openings".
Parallelization
To handle overly large datasets, FSA is able to divide the work of running all necessary pairwise comparisons and alignments to different processors. This is handled by using a "fixed-size chunking" strategy that distributes the pairwise comparisons to each available processor in chunks. Each processor is therefore able to run the posterior probability calculation on a chunk of pairwise comparisons before merging the collected data back to a single processor for sequence annealing.
Visualization
The results of the multiple sequence alignment under FSA can be displayed under the FSA's own GUI. The GUI is able to display and color label different measures of alignment quality on the columns of characters within the alignment itself. The five different measures that can be observed and are approximated under the FSA model include accuracy, sensitivity, certainty, specificity, and consistency.
Comparisons to other programs
FSA has been benchmarked against multiple alignment databases for protein (SABmark 1.65 and BAliBASE 3), RNA (BRAliBase 2.1 and Consanmix80), and DNA sequences. These benchmarks were conducted alongside other popular alignment programs such as ClustalW, MAFFT, MUSCLE, T-Coffee, and so on. Overall, at the time that FSA's abstract and research paper was received for review, FSA outperformed most alignment programs in accuracy and positive predictive values with sensitivities being on-par with the better-performing programs such as MAFFT and ProbConsRNA. Runtime comparisons were also conducted by comparing the timings to align 16S ribosomal sequences. MAFFT performed the alignment faster than the other alignment programs while MUSCLE and FSA (using a 3-state HMM and with disabled iterative refinement) were the next fastest programs.
References
Schwartz AS, Pachter L (2007) Multiple alignment by sequence annealing.
Bioinformatics 23: e24-9.
Eddy SR. Multiple alignment using hidden Markov models. Proc Int Conf Intell Syst Mol Biol. 1995;3:114-20. PMID 7584426.
External links
FSA web server
FSA source code
Bioinformatics | Fast statistical alignment | Engineering,Biology | 1,341 |
38,567,477 | https://en.wikipedia.org/wiki/Ministry%20of%20Mines%20and%20Energy%20%28Togo%29 | The Ministry of Mines and Energy () is a ministry of the government of Togo. The head office is in Lomé. As of 2013 Dammipi Noupokou is the minister.
References
External links
Ministry of Mines and Energy
Mines and Energy
Togo
Togo | Ministry of Mines and Energy (Togo) | Engineering | 54 |
18,633,469 | https://en.wikipedia.org/wiki/Sinusoidal%20spiral | In algebraic geometry, the sinusoidal spirals are a family of curves defined by the equation in polar coordinates
where is a nonzero constant and is a rational number other than 0. With a rotation about the origin, this can also be written
The term "spiral" is a misnomer, because they are not actually spirals, and often have a flower-like shape. Many well known curves are sinusoidal spirals including:
Rectangular hyperbola ()
Line ()
Parabola ()
Tschirnhausen cubic ()
Cayley's sextet ()
Cardioid ()
Circle ()
Lemniscate of Bernoulli ()
The curves were first studied by Colin Maclaurin.
Equations
Differentiating
and eliminating a produces a differential equation for r and θ:
Then
which implies that the polar tangential angle is
and so the tangential angle is
(The sign here is positive if r and cos nθ have the same sign and negative otherwise.)
The unit tangent vector,
has length one, so comparing the magnitude of the vectors on each side of the above equation gives
In particular, the length of a single loop when is:
The curvature is given by
Properties
The inverse of a sinusoidal spiral with respect to a circle with center at the origin is another sinusoidal spiral whose value of n is the negative of the original curve's value of n. For example, the inverse of the lemniscate of Bernoulli is a rectangular hyperbola.
The isoptic, pedal and negative pedal of a sinusoidal spiral are different sinusoidal spirals.
One path of a particle moving according to a central force proportional to a power of r is a sinusoidal spiral.
When n is an integer, and n points are arranged regularly on a circle of radius a, then the set of points so that the geometric mean of the distances from the point to the n points is a sinusoidal spiral. In this case the sinusoidal spiral is a polynomial lemniscate.
References
Yates, R. C.: A Handbook on Curves and Their Properties, J. W. Edwards (1952), "Spiral" p. 213–214
"Sinusoidal spiral" at www.2dcurves.com
"Sinusoidal Spirals" at The MacTutor History of Mathematics
Plane curves
Algebraic curves | Sinusoidal spiral | Mathematics | 482 |
9,774,444 | https://en.wikipedia.org/wiki/Andrew%20P.%20Vayda | Andrew P. "Pete" Vayda (December 7, 1931 – January 15, 2022) was a Hungarian-born American anthropologist and ecologist who was a distinguished professor emeritus of anthropology and ecology at Rutgers University.
Biographical background
Vayda was born in Budapest, Hungary, on December 7, 1931. He came to the United States in 1939 with his mother. He grew up in New York City. He attended Columbia University, obtaining his B.A. in 1952 and his Ph.D. in anthropology in 1956. His dissertation, based on library research he had done in New Zealand in 1954–1955, was a detailed description and analysis of Maori warfare.
A distinguished professor of anthropology and ecology at Rutgers University in New Brunswick, New Jersey, from 1972 until his retirement in 2002, he had also been a professor at Columbia University (1960–1972) and a lecturer at the University of British Columbia (1958–1960). Beginning in the 1960s and continuing into his retirement years, he taught also at various European, American, Australian, and Indonesian universities for periods of a year or less.
Social and ecological field research was conducted and/or directed by Vayda in the coral atolls of the Northern Cook Islands in 1956–57, in Papua New Guinea during the 1960s, and in Indonesia at various times and on various islands since the 1970s until 2017. He founded the journal Human Ecology in 1972 and served on the editorial boards of this and other journals through the years. From 2002, he was an independent scholar with a home base in New York City and also an adjunct professor at Monash University in Melbourne, Australia, and at the University of Indonesia in Depok, Indonesia, and a senior research associate of the Center for International Forestry Research (CIFOR) in Bogor, Indonesia. A festschrift in his honor was published in 2008. In December 2021, Human Ecology published a tribute to Vayda in celebration of his 90th birthday.
Vayda died on January 15, 2022, at the age of 90. A virtual obituary, with pictures from Vayda's various excursions and of him and his loved ones, was created in his honor.
Contributions
Vayda's long and varied career featured historical, anthropological, ecological, philosophical, and interdisciplinary research. He is known also for his criticisms of the work of others for failures of causal reasoning and explanation and for undue generalizing and theorizing in the absence of adequate supporting evidence. His published works include some hundred articles and three books. He has also edited or co-edited four books.
Maori Warfare, the book based on Vayda's Ph.D. dissertation, was first published in 1960. Now a classic, it has been regarded as the authoritative work on the subject of Maori warfare in its last stage of evolution before being greatly altered by European weapons and ways. As such, it continues to guide archaeological research in New Zealand and has been important also for anthropological and ecological studies of war. In the 1960s, Vayda extended his studies of intergroup fighting to societies in Borneo and New Guinea. His New Guinea findings have special value as products of field research carried out among groups contacted and pacified by outsiders only a few years earlier. The findings figure prominently in an important 1989 article, “Explaining Why Marings Fought.” In this, Vayda admitted to certain errors of reification and fallacies of functional explanation in some of his own earlier work and he showed how avoidable ambiguities in the meaning of questions about why people fight have led to long, unproductive, and acrimonious debates among scholars. This last theme was taken up again in a 1992 review article on the anthropology of war. Both articles are included in Vayda's 2009 essay collection, Explaining Human Actions and Environmental Changes. The 1989 article is noteworthy also as an extended illustration of Vayda's abiding interest in analyzing and explaining explanation itself and in engaging with the philosophical literature on explanation.
Vayda's year (1956–57) in the coral atolls of the Northern Cook Islands failed to produce the ethnographic monograph expected at the time from extended anthropological fieldwork. However, it did result in a number of articles, including some on such unconventional topics as the relation of island size to sexual activity and to openness to cultural innovations. Throughout his career, Vayda's efforts have been directed mainly towards the production of critical, analytic articles on various topics rather than big books with overarching themes.
Having become involved in UNESCO's Man and Biosphere Program, Vayda directed or co-directed in the 1970s and 1980s a series of interdisciplinary projects on the causes of deforestation in the Indonesian province of East Kalimantan on the island of Borneo. The projects resulted in useful data on how, why, and to what extent did specific activities such as legal and illegal logging, pepper farming by migrants from another island, and shifting cultivation, contribute to deforestation. In addition, the projects are notable for certain conceptual and methodological innovations. Thus, breaking with the anthropological tradition of conducting holistic studies of communities or societies within which the activities of interest occurred, the projects concentrated on explaining the activities by relating them to the specific contexts in which they were occurring and by making the contexts themselves the objects of research to make them broader or denser in explanation-relevant ways. This is what Bonnie McCay has referred to as “progressive vs. a priori contextualization.” The methodology, as set forth in Vayda's article, “Progressive Contextualization; Methods for Research in Human Ecology,” has been adopted by many anthropologists, geographers, and others doing applied research, and the article has been and continues to be widely cited. Following the 1980s research related to deforestation, Vayda engaged in or directed other research in Indonesia in projects related to such subjects as integrated pest management, possibilities for relocation of settlers from a national park, and possibilities for control of forest and peat fires.
Vayda's critiques of views and approaches accepted by and popular among colleagues in the social sciences and human ecology are numerous and varied. They have been described as “creative destruction” resulting in influential intellectual innovation. Included in the approaches critiqued were some Vayda himself had previously been partial to. The criticisms have pertained, inter alia, to the following for being based on theories, assumptions, and/or methodologies whereby broad conclusions either poorly supported or actually contradicted by evidence are drawn and/or practical conclusions fail to be drawn:
Earlier anthropologists’ emphasis on the social and/or ceremonial character of such institutions as potlatches in North America and pig feasts in Melanesia, with no recognition and not even consideration of their significance for subsistence.
Julian Steward's cultural ecology and Charles Frake's ethno-ecology.
The “calorific obsession” and equilibrium bias of some ecologists and ecological anthropologists.
Roy Rappaport's metaphysical holism.
Marvin Harris's cultural materialism.
Marshall Sahlins's essentialist structuralism.
The adaptationism of human behavioral ecologists (called “Darwinian Ecological Anthropologists” by Vayda).
Cognitive anthropologists’ failure to deal with the knowledge bases of practical human activities or actions.
Steve Lansing's selective use of evidence to support his modelling of Balinese agro-ecological change.
The undue claims made for the holistic study of local knowledge systems as practical guides to economic development and environmental conservation.
Such whole fields as political ecology and spiritual ecology, criticized for their promotion of confirmation bias by virtue of their causes-to-effects rather than effects-to-causes research methodology (see below).
The methodological approach favored by Vayda and his frequent collaborator, Bradley Walters, drew on pragmatic features of the work of such philosophers as David Lewis on causal explanation and Charles S. Peirce on abductive reasoning. The approach had the following key features (or “admonitions” as the geographer/political ecologist Paul Robbins has called some of them):
Events, including human actions, were made the usual objects of explanation. Among examples from Vayda's work were the events comprising deforestation, intergroup fighting, migration, forest fires, and adoption or non-adoption of integrated pest management.
Explanation and explanation-oriented research proceed from the events that are regarded as the effects to be explained (i.e., the explananda) to their causes and not vice versa, thus reducing the confirmation bias which, according to Vayda and Walters, was promoted by the causes-to-effects research characteristic of such fields as political ecology.
Multiple and/or alternative causal possibilities were investigated, with some usually being eliminated while others, comprising some portion of the causal histories of the explanandum events, were left to stand as likely or possible explanations.
The main goal of research and explanation was seen as simply answering why-questions about concrete changes or events of interest and not as the kind of development or evaluation of general theories or models favored by many scholars, although theories or models were sometimes used as sources of the causal possibilities considered.
In his last decades Vayda used this methodological approach in explanation-oriented research on forest and peat fires in Indonesia.
Publications
Vayda published some hundred articles and several books, including Explaining Human Actions and Environmental Changes, a selection of his essays on explanation and explanation-oriented research in the social sciences and human ecology, published by AltaMira Press in 2009, and Causal Explanation for Social Scientists: A Reader, co-edited by him and Bradley B. Walters, published by AltaMira Press in 2011. A festschrift in his honor, Against the Grain: The Vayda Tradition in Human Ecology and Ecological Anthropology, with a concluding chapter by him on “Causal Explanation as a Research Goal,” was published in 2008 by AltaMira Press.
Books by Vayda
Explaining Human Actions and Environmental Changes, Lanham, MD: AltaMira Press. 2009
War in Ecological Perspective, New York: Plenum Press. 1976.
Maori Warfare, Wellington, NZ: Polynesian Society, 1960, reprinted 1970.
Books Edited
Causal Explanation for Social Scientists: A Reader (co-edited with Bradley B. Walters), Lanham, MD: AltaMira Press. 2011
Environment and Cultural Behavior, Garden City, NY: The Natural History Press. 1969
Peoples and Cultures of the Pacific, Garden City, NY: The Natural History Press. 1968
Man, Culture, and Animals: The Role of Animals in Human Ecological Adjustments (co-edited with Anthony Leeds), Washington, D.C.: American Association for the Advancement of Science, 1965.
Past Graduate and PhD students
Cristina Eghenter, Social Development Deputy Director, World Wide Fund for Nature Indonesia.
Kevin Flesher, Research Director, Centro de Estudos de Biodiversidade, Michelin Ecological Reserve, Ituberá, Brazil.
Timothy C. Jessup, Indonesia Green Growth Specialist, Global Green Growth Institute.
Jay F. Kelly, Associate Professor of Biology and Environmental Science, Raritan Valley Community College.
Bonnie J. McCay, Board of Governors Distinguished Service Professor-Emerita, Rutgers University.
Christine Padoch, Senior Curator Emerita of the Institute of Economic Botany, New York Botanical Garden.
Roy Rappaport (deceased), Professor of Anthropology, University of Michigan.
Iwan Tjitradjaja (deceased), Head, Department of Anthropology, University of Indonesia.
Patricia J. Vondal, International Development Consultant.
Bradley B. Walters, Professor of Geography & Environment at Mount Allison University, Canada
See also
Progressive contextualization
References
Other Sources
Walters, B.B., 2013. “Vayda, Andrew P.” In: McGee, R.J., and Warms, R.L., eds., Theory in Social and Cultural Anthropology: An Encyclopedia, Thousand Oaks, CA: Sage Publications, pp. 889–891.
McCay, B.J., 2008. “An intellectual history of ecological anthropology.” In: Walters, B.B., McCay, B.J., West, P., and Lees, S., eds., Against the Grain: The Vayda Tradition in Human Ecology and Ecological Anthropology, Lanham, MD: AltaMira Press, pp. 11–26.
Vayda, A.P., 1994. “Intellectual roots.” In: Borofsky, R., ed., Assessing Cultural Anthropology, New York: McGraw-Hill. 1994, pp. 339–340.
A 53-minute video interview of Vayda on his life and work as of April 2008. The interview took place on April 5, 2008 in Sackville, New Brunswick, Canada, and was conducted by Dr. Patricia Kelly Spurles of Mount Allison University. Uploaded to YouTube by Professor Alan Macfarlane of King's College, Cambridge University, the video is included in a series of interviews with scholars.
Walters, B. B., Doolittle, W. E., Klooster, D., Rocheleau, D., Turner, B. L., II, and Vayda, A. P., 2011. “Book review forum: Explaining human actions and environmental changes” [Five reviews of Vayda's 2009 book, followed by his reply]. Dialogues in Human Geography 1:370–389.
ResearchGate's almost complete list of Vayda's publications, many of them available for free download (www.researchgate.net). (There is a much less complete list at Academia.edu.)
1931 births
2022 deaths
American anthropologists
Hungarian emigrants to the United States
Rutgers University faculty
Environmental social scientists
Scientists from Budapest
Scientists from New York City
Columbia College (New York) alumni
Columbia Graduate School of Arts and Sciences alumni | Andrew P. Vayda | Environmental_science | 2,858 |
30,940,945 | https://en.wikipedia.org/wiki/Agaricus%20langei | Agaricus langei is a species of fungus in the genus Agaricus.
See also
List of Agaricus species
References
External links
langei
Fungi described in 1950
Fungi of Europe
Edible fungi
Fungus species | Agaricus langei | Biology | 43 |
3,555,539 | https://en.wikipedia.org/wiki/Tau%20effect | The tau effect is a spatial perceptual illusion that arises when observers judge the distance between consecutive stimuli in a stimulus sequence. When the distance from one stimulus to the next is constant, and the time elapsed from one stimulus to the next is also constant, subjects tend to judge the distances, correctly, as equal. However, if the distance from one stimulus to the next is constant, but the time elapsed from one stimulus to the next is not constant, then subjects tend to misperceive the interval that has the shorter temporal interval as also having a shorter spatial interval. Thus, the tau effect reveals that stimulus timing affects the perception of stimulus spacing. Time is also a perceived quantity and subject to its own illusions; research indicates that in the tau effect, perceived stimulus spacing follows perceived (phenomenal) time rather than actual (physical) time.
In different sensory modalities
The tau effect can occur with visual, auditory, or tactile stimuli. In touch, the tau effect was first described by Gelb (1914). It was later given its name by Helson (1930) and characterized in detail by Helson and King (1931). In addition to the unimodal (i.e., purely visual, auditory, or tactile) tau effect, crossmodal tau effects can occur. For instance, Kawabe et al. (2008) showed that the time intervals between auditory tones could affect subjects' perceptual judgements of the spatial interval between visual flashes in a manner consistent with that predicted by the tau effect.
Theories based in velocity expectation
Physically, traversed space and elapsed time are linked by velocity. It is logical, then, to consider that the tau effect occurs as a consequence of the brain's assumption regarding stimulus velocity. Indeed, different theories regarding the brain's expectations about stimulus velocity have been put forward in an effort to explain the tau effect.
Constant velocity hypothesis
According to the constant velocity hypothesis proposed by Jones and Huang (1982), perception incorporates a prior expectation for constant speed. Therefore, given the temporal intervals marked by sequential stimuli, the brain expects spatial intervals that would yield constant velocity movement (i.e., uniform motion). One limitation of this theory, pointed out by Goldreich (2007), is that it does not explain why even two stimuli pressed in rapid succession against the skin are perceived as closer together the shorter the temporal interval between them is. In the absence of a third stimulus that creates a second spatial and temporal interval, the constant velocity hypothesis can have no bearing on this two-stimulus situation.
Low-speed expectation
According to a tactile Bayesian perceptual model put forward by Goldreich (2007), the brain expects that tactile stimuli tend to move slowly. The Bayesian model reaches an optimal probabilistic inference by combining uncertain spatial and temporal sensory information with a prior expectation for low-speeds. The expectation that stimuli tend to move slowly results in the perceptual underestimation of the spatial separation between rapidly consecutive stimuli ("perceptual length contraction"), thereby reproducing the tau effect and related illusions.
Unlike the constant velocity hypothesis, the Bayesian model replicates the underestimation in perceived distance that occurs even when only two stimuli are presented in rapid succession. For the case of two taps to the skin, the Bayesian model perceives the length between taps, l*, to be a function of the actual length, l, and the elapsed time, t:
The parameter tau (τ) is proportional to the observer's spatial uncertainty (specifically, it is the spatial standard deviation divided by the low-speed prior standard deviation). Consistent with this model, Tong et al. (2016) showed that stimulus pairs consisting of weaker taps, which are localized with greater uncertainty than stronger taps, result in more pronounced length contraction. Modeling the tau effect that occurs in the perception of 3-tap sequences, Goldreich and Tong (2013) compared the Bayesian model with a low-speed expectation to a Bayesian model with a low-acceleration expectation — similar to the constant-velocity hypothesis. They found that the low-speed prior model provided better fits to the human tactile tau effect data. When time is inaccurately perceived (i.e., because of the kappa effect), the Bayesian observer model judges stimulus spacing to follow perceived time rather than actual time, consistent with reports from human subjects.
Related illusions
A spatial perceptual illusion that seems to be closely related to the tau effect is the rabbit illusion. In the tactile rabbit illusion, a rapid sequence of taps delivered first near the wrist and then near the elbow creates the sensation of sequential taps hopping up the arm from the wrist towards the elbow, although no physical stimulus was applied between the two actual stimulus locations. Like the tau effect, the rabbit illusion has been observed not just in touch, but also in audition and vision.
If observers interpret rapid stimulus sequences in light of an expectation regarding velocity, then it would be expected that not only spatial, but also temporal illusions would result. This indeed occurs in the kappa effect: When the temporal separation between stimuli is constant and the spatial separation is varied, the observer's temporal interval judgment is influenced by the spatial distance between consecutive stimuli. Specifically, longer spatial intervals are perceived to occupy longer temporal intervals. The kappa effect is therefore the temporal perceptual analog of the tau effect.
Goldreich (2007) linked the tau, rabbit, and kappa effects to the same underlying expectation regarding movement speed. He noted that, when stimuli move rapidly across space, "perception strikingly shrinks the intervening distance, and expands the elapsed time, between consecutive events". Goldreich (2007) termed these two fundamental perceptual distortions "perceptual length contraction" (tau effect, rabbit illusion) and "perceptual time dilation" (kappa effect) in analogy with the physical length contraction and time dilation of the theory of relativity. Perceptual length contraction and perceptual time dilation result from the same Bayesian observer model, one that expects stimuli to move slowly. Analogously, in the theory of relativity, length contraction and time dilation both occur when a physical speed (the speed of light) cannot be exceeded.
Related
General tau theory
References
Auditory illusions
Tactile illusions
Optical illusions
Psychological effects
Perception
Bayesian inference | Tau effect | Physics | 1,324 |
4,111 | https://en.wikipedia.org/wiki/Bioleaching | Bioleaching is the extraction or liberation of metals from their ores through the use of living organisms. Bioleaching is one of several applications within biohydrometallurgy and several methods are used to treat ores or concentrates containing copper, zinc, lead, arsenic, antimony, nickel, molybdenum, gold, silver, and cobalt.
Bioleaching falls into two broad categories. The first, is the use of microorganisms to oxidize refractory minerals to release valuable metals such and gold and silver. Most commonly the minerals that are the target of oxidization are pyrite and arsenopyrite.
The second category is leaching of sulphide minerals to release the associated metal, for example, leaching of pentlandite to release nickel, or the leaching of chalcocite, covellite or chalcopyrite to release copper.
Process
Bioleaching can involve numerous ferrous iron and sulfur oxidizing bacteria, including Acidithiobacillus ferrooxidans (formerly known as Thiobacillus ferrooxidans) and Acidithiobacillus thiooxidans (formerly known as Thiobacillus thiooxidans). As a general principle, in one proposed method of bacterial leaching known as Indirect Leaching, Fe3+ ions are used to oxidize the ore. This step is entirely independent of microbes. The role of the bacteria is further oxidation of the ore, but also the regeneration of the chemical oxidant Fe3+ from Fe2+. For example, bacteria catalyse the breakdown of the mineral pyrite (FeS2) by oxidising the sulfur and metal (in this case ferrous iron, (Fe2+)) using oxygen. This yields soluble products that can be further purified and refined to yield the desired metal.
Pyrite leaching (FeS2):
In the first step, disulfide is spontaneously oxidized to thiosulfate by ferric ion (Fe3+), which in turn is reduced to give ferrous ion (Fe2+):
(1) spontaneous
The ferrous ion is then oxidized by bacteria using oxygen:
(2) (iron oxidizers)
Thiosulfate is also oxidized by bacteria to give sulfate:
(3) (sulfur oxidizers)
The ferric ion produced in reaction (2) oxidized more sulfide as in reaction (1), closing the cycle and given the net reaction:
(4)
The net products of the reaction are soluble ferrous sulfate and sulfuric acid.
The microbial oxidation process occurs at the cell membrane of the bacteria. The electrons pass into the cells and are used in biochemical processes to produce energy for the bacteria while reducing oxygen to water. The critical reaction is the oxidation of sulfide by ferric iron. The main role of the bacterial step is the regeneration of this reactant.
The process for copper is very similar, but the efficiency and kinetics depend on the copper mineralogy. The most efficient minerals are supergene minerals such as chalcocite, Cu2S and covellite, CuS. The main copper mineral chalcopyrite (CuFeS2) is not leached very efficiently, which is why the dominant copper-producing technology remains flotation, followed by smelting and refining. The leaching of CuFeS2 follows the two stages of being dissolved and then further oxidised, with Cu2+ ions being left in solution.
Chalcopyrite leaching:
(1) spontaneous
(2) (iron oxidizers)
(3) (sulfur oxidizers)
net reaction:
(4)
In general, sulfides are first oxidized to elemental sulfur, whereas disulfides are oxidized to give thiosulfate, and the processes above can be applied to other sulfidic ores. Bioleaching of non-sulfidic ores such as pitchblende also uses ferric iron as an oxidant (e.g., UO2 + 2 Fe3+ ==> UO22+ + 2 Fe2+). In this case, the sole purpose of the bacterial step is the regeneration of Fe3+. Sulfidic iron ores can be added to speed up the process and provide a source of iron. Bioleaching of non-sulfidic ores by layering of waste sulfides and elemental sulfur, colonized by Acidithiobacillus spp., has been accomplished, which provides a strategy for accelerated leaching of materials that do not contain sulfide minerals.
Further processing
The dissolved copper (Cu2+) ions are removed from the solution by ligand exchange solvent extraction, which leaves other ions in the solution. The copper is removed by bonding to a ligand, which is a large molecule consisting of a number of smaller groups, each possessing a lone electron pair. The ligand-copper complex is extracted from the solution using an organic solvent such as kerosene:
Cu2+(aq) + 2LH(organic) → CuL2(organic) + 2H+(aq)
The ligand donates electrons to the copper, producing a complex - a central metal atom (copper) bonded to the ligand. Because this complex has no charge, it is no longer attracted to polar water molecules and dissolves in the kerosene, which is then easily separated from the solution. Because the initial reaction is reversible, it is determined by pH. Adding concentrated acid reverses the equation, and the copper ions go back into an aqueous solution.
Then the copper is passed through an electro-winning process to increase its purity: An electric current is passed through the resulting solution of copper ions. Because copper ions have a 2+ charge, they are attracted to the negative cathodes and collect there.
The copper can also be concentrated and separated by displacing the copper with Fe from scrap iron:
Cu2+(aq) + Fe(s) → Cu(s) + Fe2+(aq)
The electrons lost by the iron are taken up by the copper. Copper is the oxidising agent (it accepts electrons), and iron is the reducing agent (it loses electrons).
Traces of precious metals such as gold may be left in the original solution. Treating the mixture with sodium cyanide in the presence of free oxygen dissolves the gold. The gold is removed from the solution by adsorbing (taking it up on the surface) to charcoal.
With fungi
Several species of fungi can be used for bioleaching. Fungi can be grown on many different substrates, such as electronic scrap, catalytic converters, and fly ash from municipal waste incineration. Experiments have shown that two fungal strains (Aspergillus niger, Penicillium simplicissimum) were able to mobilize Cu and Sn by 65%, and Al, Ni, Pb, and Zn by more than 95%. Aspergillus niger can produce some organic acids such as citric acid. This form of leaching does not rely on microbial oxidation of metal but rather uses microbial metabolism as source of acids that directly dissolve the metal.
Feasibility
Economic feasibility
Bioleaching is in general simpler and, therefore, cheaper to operate and maintain than traditional processes, since fewer specialists are needed to operate complex chemical plants. And low concentrations are not a problem for bacteria because they simply ignore the waste that surrounds the metals, attaining extraction yields of over 90% in some cases. These microorganisms actually gain energy by breaking down minerals into their constituent elements. The company simply collects the ions out of the solution after the bacteria have finished.
Bioleaching can be used to extract metals from low concentration ores such as gold that are too poor for other technologies. It can be used to partially replace the extensive crushing and grinding that translates to prohibitive cost and energy consumption in a conventional process. Because the lower cost of bacterial leaching outweighs the time it takes to extract the metal.
High concentration ores, such as copper, are more economical to smelt rather bioleach due to the slow speed of the bacterial leaching process compared to smelting. The slow speed of bioleaching introduces a significant delay in cash flow for new mines. Nonetheless, at the largest copper mine of the world, Escondida in Chile the process seems to be favorable.
Economically it is also very expensive and many companies once started can not keep up with the demand and end up in debt.
In space
In 2020 scientists showed, with an experiment with different gravity environments on the ISS, that microorganisms could be employed to mine useful elements from basaltic rocks via bioleaching in space.
Environmental impact
The process is more environmentally friendly than traditional extraction methods. For the company this can translate into profit, since the necessary limiting of sulfur dioxide emissions during smelting is expensive. Less landscape damage occurs, since the bacteria involved grow naturally, and the mine and surrounding area can be left relatively untouched. As the bacteria breed in the conditions of the mine, they are easily cultivated and recycled.
Toxic chemicals are sometimes produced in the process. Sulfuric acid and H+ ions that have been formed can leak into the ground and surface water turning it acidic, causing environmental damage. Heavy ions such as iron, zinc, and arsenic leak during acid mine drainage. When the pH of this solution rises, as a result of dilution by fresh water, these ions precipitate, forming "Yellow Boy" pollution. For these reasons, a setup of bioleaching must be carefully planned, since the process can lead to a biosafety failure. Unlike other methods, once started, bioheap leaching cannot be quickly stopped, because leaching would still continue with rainwater and natural bacteria. Projects like Finnish Talvivaara proved to be environmentally and economically disastrous.
See also
Phytomining
References
Further reading
T. A. Fowler and F. K. Crundwell – "Leaching of zinc sulfide with Thiobacillus ferrooxidans"
Brandl H. (2001) "Microbial leaching of metals". In: Rehm H. J. (ed.) Biotechnology, Vol. 10. Wiley-VCH, Weinheim, pp. 191–224
Biotechnology
Economic geology
Metallurgical processes
Applied microbiology | Bioleaching | Chemistry,Materials_science,Biology | 2,169 |
985,187 | https://en.wikipedia.org/wiki/Driving%20simulator | Driving simulators are used for entertainment as well as in training of driver's education courses taught in educational institutions and private businesses. They are also used for research purposes in the area of human factors and medical research, to monitor driver behavior, performance, and attention and in the car industry to design and evaluate new vehicles or new advanced driver assistance systems.
Training
Driving simulators are being increasingly used for training drivers. Versions exist for cars, trucks, buses, etc.
Uses
Novice driver training and testing
Professional driver training and testing
Training in critical driving conditions
Testing the effects of impairment on driver performance
Analysis of the driver behaviours
Analysis of driver responses
Evaluating user performances in different conditions (handling of controls)
Assessing fitness to drive for aging drivers
Testing future in-vehicle technologies on drivers or passengers (Human -Machine Interface)
entertainment and fun
Types
Ambulance simulator: Used to train and assess ambulance drivers in basic and advanced vehicle control skills as well as how to respond to emergencies and interact with other emergency responders.
Car simulator: Used to train and test novice drivers in all the skills required to pass a driver's license road test as well as hazard perception and crash risk mitigation.
Modular-design simulator: Interchangeable vehicle cabins or cockpits can be configured for use as tractor/trailer trucks, dump trucks and other construction vehicles, airport-operated vehicles, emergency response and police pursuit vehicles, buses, subway trains, passenger vehicles, and heavy equipment such as cranes.
Multi-station driving simulator: This type of simulator enables one instructor to train more drivers at the same time thus saving time and reducing costs... These systems are equipped with instructor stations connected to control several driving simulators.
Truck simulator: Used to train and assess novice and experienced truck drivers in skills ranging from basic control maneuvers, e.g. shifting and backing, to advanced skills, e.g. fuel efficiency, rollover prevention, defensive driving.
Bus simulator: is used to train bus drivers on route familiarisation, safe driving techniques, fuel efficiency techniques. It can be used for training drivers on a variety of bus models and on different types of gear transmissions.
Physical simulator: Large scale simulators employ Stewart platforms and xy tables to physically move the driver around in 6-axis space, simulating acceleration, braking and centripetal forces, similar to physical flight simulators.
Entertainment
In the 1980s, it became a trend for arcade racing games to use hydraulic motion simulator arcade cabinets. The trend was sparked by Sega's "taikan" games, with "taikan" meaning "body sensation" in Japanese. The "taikan" trend began when Yu Suzuki's team at Sega (later known as Sega AM2) developed Hang-On (1985), a racing video game where the player sits on and moves a motorbike replica to control the in-game actions. Suzuki's team at Sega followed it with hydraulic motion simulator cockpit cabinets for later racing games such as Out Run (1986). Sega have since continued to manufacture motion simulator cabinets for arcade racing games through to the 2010s.
In 1991, Namco released the arcade game Mitsubishi Driving Simulator, co-developed with Mitsubishi. It was a serious educational street driving simulator that used 3D polygon technology and a sit-down arcade cabinet to simulate realistic driving, including basics such as ensuring the car is in neutral or parking position, starting the engine, placing the car into gear, releasing the hand-brake, and then driving. The player can choose from three routes while following instructions, avoiding collisions with other vehicles or pedestrians, and waiting at traffic lights; the brakes are accurately simulated, with the car creeping forward after taking the foot off the brake until the hand-brake is applied. Leisure Line magazine considered it the "hit of the show" upon its debut at the 1991 JAMMA show. It was designed for use by Japanese driving schools, with a very expensive cost of AU$150,000 or per unit.
Advances in processing power have led to more realistic simulators known as sim racing games on home systems, beginning with Papyrus Design Group's groundbreaking IndyCar Racing (1993) and Grand Prix Legends (1998) for PC and Gran Turismo (1997) for home consoles.
Occasionally, a racing game or driving simulator will also include an attachable steering wheel that can be used to play the game in place of a controller. The wheel, which is usually plastic, may also include pedals to add to the game's reality. These wheels are usually used only for arcade and computer games.
In addition to the myriad commercial releases there is a bustling community of amateur coders working on closed and open source free simulators. Some of the major features popular with fans of the genre are online racing, realism and diversity of cars and tracks.
Research
Driving simulators are used at research facilities for many purposes. Many vehicle manufacturers operate driving simulators, e.g. BMW, Ford, Renault. Many universities also operate simulators for research. Driving simulators allow researchers to study driver training issues and driver behavior under conditions in which it would be illegal and/or unethical to place drivers. For instance, studies of driver distraction would be dangerous and unethical (because of the inability to obtain informed consent from other drivers) to do on the road.
With the increasing use of various in-vehicle information systems (IVIS) such as satellite navigation systems, cell phones, DVD players and e-mail systems, simulators are playing an important rule in assessing the safety and utility of such devices.
Fidelity
There exists a number of types research driving simulators, with a wide range of capabilities. The most complex, like the National Advanced Driving Simulator, have a full-sized vehicle body, with six-axis movement and 360-degree visual displays. On the other end of the range are simple desktop simulators that are often implemented using a computer monitor for the visual display and a videogame-type steering wheel and pedal input devices. These low cost simulators are used readily in the evaluation of basic and clinically oriented scientific questions.
The issue is complicated by political and economic factors, as facilities with low-fidelity simulators claim their systems are "good enough" for the job, while the high-fidelity simulator groups insist that their (considerably more expensive) systems are necessary. Research into motion fidelity indicates that, while some motion is necessary in a research driving simulator, it does not need to have enough range to match real-world forces. Recent research has also considered the use of the real-time photo-realistic video content that reacts dynamically to driver behaviour in the environment.
Validity
There is a question of validity—whether results obtained in the simulator are applicable to real-world driving. One review of research studies found that driver behavior on a driving simulator approximates (relative validity) but does not exactly replicate (absolute validity) on-road driving behavior. Another study found absolute validity for the types and number of driver errors committed on a simulator and on the road. Yet another study found that drivers who reported impaired performance on a low fidelity driving simulator were significantly more likely to take part in an accident in which the driver was at least partially at fault, within five years after the simulator session. Some research teams are using automated vehicles to recreate simulator studies on a test track, enabling a more direct comparison between the simulator study and the real world. As computers have grown faster and simulation is more widespread in the automotive industry, commercial vehicle math models that have been validated by manufacturers are seeing use in simulators.
See also
Full motion racing simulator
Virtual reality simulator
Sim racing, collective term for auto racing games which aim to be realistic, but do not necessarily include motion simulation output
Flight simulator
Full flight simulator
Simulator ride
References
Educational software
Automotive software
Simulation software
Simulator | Driving simulator | Technology | 1,570 |
14,118,838 | https://en.wikipedia.org/wiki/Heat%20shock%20factor%20protein%201 | Heat shock factor protein 1 (HSF 1) is a protein that in humans is encoded by the HSF1 gene. HSF1 is highly conserved in eukaryotes and is the primary mediator of transcriptional responses to proteotoxic stress with important roles in non-stress regulation such as development and metabolism.
Structure
Human HSF1 consists of several domains which regulate its binding and activity.
DNA-Binding Domain (DBD)
This N-terminal domain of approximately 100 amino acids is the most highly conserved region in the HSF protein family and consists of a helix-turn-helix loop. The DBD of each HSF1 monomer recognizes the sequence nGAAn on target DNA. Repeated sequences of the nGAAn pentamer constitute heat shock elements (HSEs) for active HSF1 trimers to bind.
Oligomerization Domain (Leucine Zipper Domains)
The two regions responsible for oligomerization between HSF1 monomers are leucine zipper (LZ) domains 1-3 and 4 (these regions are also commonly referred to as HR-A/B and HR-C). LZ1-3 is situated just downstream of the DBD while LZ4 is located between the RD and the C-terminal TAD. Under non-stress conditions, spontaneous HSF1 activation is negatively regulated by the interaction between LZ1-3 and LZ4. When induced by stress, the LZ1-3 region breaks away from the LZ4 region and forms a trimer with other HSF1 LZ1-3 domains to form a triple coiled-coil.
Regulatory Domain (RD)
The structures of the C-terminal RD and TAD of HSF1 have not been clearly resolved due to their dynamic nature. However, it is known that the RD is situated between the two regions of the oligomerization domain. The RD has been shown to regulate the TAD through negative control by repressing TAD in the absence of stress, a role that is inducibly regulated through posttranslational modifications.
Trans-Activation Domain (TAD)
This C-terminal region spans the last 150 amino acids of the HSF1 protein and contains 2 TADs (TAD1 and TAD2). TAD1, which sits at amino acids 401-420, is largely hydrophobic and is predicted to take on an alpha-helical conformation. TAD1 has been shown to directly interact with target DNA to direct HSF1's transcriptional activation. The structure of TAD2, amino acids 431-529, is not expected to be helical as it contains proline residues in addition to hydrophobic and acidic ones. The function of the HSF1 TAD is still largely uncharacterized, but Hsp70 has been shown to bind with this domain, which could describe the mechanism by which Hsp70 negatively regulates HSF1.
Function
The HSF1 protein regulates the heat shock response (HSR) pathway in humans by acting as the major transcription factor for heat shock proteins. The HSR plays a protective role by ensuring proper folding and distribution of proteins within cells. This pathway is induced by not only temperature stress, but also by a variety of other stressors such as hypoxic conditions and exposure to contaminants. HSF1 transactivates genes for many cytoprotective proteins involved in heat shock, DNA damage repair, and metabolism. This illustrates the versatile role of HSF1 in not only the heat shock response, but also in aging and diseases.
Mechanism of action
Under non-stress conditions, HSF1 exists primarily as an inactive monomer located throughout the nucleus and the cytoplasm. In its monomeric form, HSF1 activation is repressed by interaction with chaperones such as heat shock proteins Hsp70 and Hsp90, and TRiC/CCT. In the event of proteotoxic stress such as heat shock, these chaperones are released from HSF1 to perform their protein-folding roles; simultaneously, the export of HSF1 to the cytoplasm is inhibited. These actions allow HSF1 to trimerize and accumulate in the nucleus to stimulate transcription of target genes.
Clinical significance
HSF1 is a promising drug target in cancer and proteopathy.
The genes activated by HSF1 under heat shock conditions have been recently shown to differ from those activated in malignant cancer cells, and this cancer-specific HSF1 panel of genes has indicated poor prognosis in breast cancer. The ability of cancer cells to use HSF1 in a unique manner gives this protein significant clinical implications for therapies and prognoses.
In the case of protein-folding diseases such as Huntington's disease (HD), however, induction of the heat shock response pathway would prove beneficial. In recent years, using cells that express the poly-glutamine expansion found in HD, it has been shown that both the HSR and HSF1 levels are reduced after heat shock. This reduced ability of diseased cells to respond to stress helps to explain the toxicity associated with certain diseases.
Interactions
HSF1 has been shown to interact with:
CEBPB, HSF2, HSPA1A, HSPA4, Heat shock protein 90kDa alpha (cytosolic) member A1, NCOA6, RALBP1 and SYMPK.
See also
Heat shock factor
Heat shock protein
Transcription factor
References
Further reading
External links
Transcription factors | Heat shock factor protein 1 | Chemistry,Biology | 1,135 |
7,514,465 | https://en.wikipedia.org/wiki/Phytotoxin | Phytotoxins are substances that are poisonous or toxic to the growth of plants. Phytotoxic substances may result from human activity, as with herbicides, or they may be produced by plants, by microorganisms, or by naturally occurring chemical reactions.
The term is also used to describe toxic chemicals produced by plants themselves, which function as defensive agents against their predators. Most examples pertaining to this definition of phytotoxin are members of various classes of specialised or secondary metabolites, including alkaloids, terpenes, and especially phenolics, though not all such compounds are toxic or serve defensive purposes. Phytotoxins may also be toxic to humans.
Toxins produced by plants
Alkaloids
Alkaloids are derived from amino acids, and contain nitrogen. They are medically important by interfering with components of the nervous system affecting membrane transport, protein synthesis, and enzyme activities. They generally have a bitter taste. Alkaloids usually end in -ine (caffeine, nicotine, cocaine, morphine, ephedrine).
Terpenes
Terpenes are made of water-insoluble lipids, and synthesized from acetyl-CoA or basic intermediates of glycolysis They often end in -ol (menthol) and comprise the majority of plant essential oils.
Monoterpenes are found in gymnosperms and collect in the resin ducts and may be released after an insect begins to feed to attract the insect's natural enemies.
Sesquiterpenes are bitter tasting to humans and are found on glandular hairs or subdermal pigments.
Diterpenes are contained in resin and block and deter insect feeding. Taxol, an important anticancer drug is found in this group.
Triterpenes mimic the insect molting hormone ecdysone, disrupting molting and development and is often lethal. They are usually found in citrus fruit, and produce a bitter substance called limonoid that deters insect feeding.
Glycosides are made of one or more sugars combined with a non-sugar like aglycone, which usually determines the level of toxicity. Cyanogenic glycosides are found in many plant seeds like cherries, apples, and plums. Cyanogenic glycosides produce cyanide and are extremely poisonous. Cardenolides have a bitter taste and influence NA+/K+ activated ATPases in human heart, they may slow or strengthen the heart rate. Saponins have lipid- and water-soluble components with detergent properties. Saponins form complexes with sterols and interfere with their uptake.
Phenolics
Phenolics are made of a hydroxyl group bonded to an aromatic hydrocarbon. Furanocoumarin is a phototoxic phenolic, and is non-toxic until activated by light. Furanocoumarin blocks the transcription and repair of DNA. Tannins are another group of phenolics important in tanning leather. Lignins, also a group of phenolics, are the most common compounds on Earth, and help conduct water in plant stems and fill spaces in the cell.
Substances toxic to plants
Herbicides
Herbicides usually interfere with plant growth and often imitate plant hormones.
ACCase Inhibitors kill grasses and inhibit the first step in lipid synthesis, acetyl-CoA carboxylase, thus affecting cell membrane production in the meristems. They do not affect dicots plants.
ALS Inhibitors affect grasses and dicots by inhibiting the first step in some amino acid synthesis, acetolactate synthesis. The plants are slowly starved of these amino acids and eventually DNA synthesis stops.
ESPS Inhibitors affect grasses and dicots by inhibiting the first step in the synthesis of tryptophan, phenylalanine and tyrosine, enolpyruvylshikimate 3-phosphate synthase enzyme.
Photosystem II Inhibitors reduce the electron flow from water to NADPH2+ causing electrons to accumulate on chlorophyll molecules and excess oxidation to occur. The plant will eventually die.
Synthetic Auxin mimics plant hormones and can affect the plant cell membrane.
Bacterial phytotoxins
Tabtoxin is produced by Pseudomonas syringae pv. tabaci that may cause toxic concentrations of ammonia to build up. This buildup of ammonia causes leaf chlorosis.
Glycopeptides are produced by a number of bacteria and have been indicated in disease development. A glycopeptide from Corynebacterium sepedonicum causes rapid wilt and marginal necrosis. A toxin from Corynebacterium insidiosum causes plugging of the plant stem interfering with water movement between cells. Amylovorin is a polysaccharide from Erwinia amylovora and causes wilting in rosaceous plants. A polysaccharide from Xanthomonas campestris obstructs water flow through phloem causing black rot in cabbage.
Phaseolotoxin is a modified tripeptide [Nδ-(N′-sulfodiaminophosphinyl)-ornithyl-alanyl-homoarginine] produced by certains strains of Pseudomonas syringae pv. phaseolicola, Pseudomonas syringae pv. actinidiae and strain Pseudomonas syringae pv. syringae CFBP 3388. Phaseolotoxin is a reversible inhibitor of the enzyme ornithine carbamoyltransferase (OCTase; EC 2.1.3.3), which catalyzes the formation of citrulline from ornithine and carbamoylphosphate in the arginine biosynthetic pathway. Phaseolotoxin is an effective inhibitor of OCTase activity from plant, mammalian, and bacterial sources and causes a phenotypic requirement for arginine. Additionally, phaseolotoxin inhibits the enzyme ornithine decarboxylase (EC 4.1.1.17), which is involved in the biosynthesis of polyamines.
Rhizobiotoxine, produced by Rhizobium japonicum, causes the root nodules of some soy bean plants to become chlorotic.
See also
References | Phytotoxin | Chemistry | 1,334 |
2,909,299 | https://en.wikipedia.org/wiki/Santonin | Santonin is a drug which was widely used in the past as an anthelminthic. It is an organic compound consisting of colorless flat prisms, turning slightly yellow from the action of light and soluble in alcohol, chloroform and boiling water.
According to the US Pharmacopoeia, santonin occurs "in colorless, shining, flattened, prismatic crystals, odorless and nearly tasteless when first put in the mouth, but afterward developing a bitter taste; not altered by exposure to air, but turning yellow on exposure to light. Nearly insoluble in cold water; soluble in 40 parts of alcohol at 15 °C. (59 °F.), in 250 parts of boiling water, and in 8 parts of boiling alcohol; also soluble in 140 parts of ether, in 4 parts of chloroform, and in solutions of caustic alkalies. When heated to 170 °C. (338 °F.), santonin melts, and forms, if rapidly cooled, an amorphous mass, which instantly crystallizes oil coming in contact with a minute quantity of one of its solvents. At a higher temperature, it sublimes partly unchanged, and, when ignited, it is consumed, leaving no residue. Santonin is neutral to litmus paper moistened with alcohol. Santonin yields, with an alcoholic solution of potassium hydroxide, a bright pinkish-red liquid, which gradually becomes colorless. From its solution in caustic alkalies, santonin is completely precipitated by supersaturation with an acid".
Isolation
It is derived from santonica (the unexpanded flower-heads of Artemisia maritima var. stechmanniana). Others refer to A. cina or A. chamaemelifolia as being the derivative species.
The determination of the structure of santonin was the subject of intense early work. The initial photoproduct obtained from santonin is lumisantonin. In this rearrangement, the C-3 carbonyl group moves to C-2, the C-4 methyl moves to C-1, and the C-10 carbon inverts.
Anthelminthic use
Santonin paralyzes parasitic worms (helminths), allowing them to be passed out of the body. Santonin has the effect of paralyzing the anterior (front) end of the worm, while having a stimulant effect on the posterior end, depending on the concentration. Because of this, the worm cannot coordinate itself, and loses its ability to maintain its position in the host. By using a purgative, the worm can easily be passed out. Experiments in the 1880s showed that even after 40 hours, santonin had no lethal effect on roundworms using a saturated solution in dilute alkali.
Santonin was formerly listed in U.S. and British pharmacopoeia, but it has fallen out of use with the development of safer ascaricides and is no longer registered as a drug in most countries.
Reactions and properties
Santonin can be converted to santonic acid (C15H20O4) via based-catalyzed hydrolysis followed by a multistep rearrangement process.
Santonin dissolves in alkalies with formation of salts of this carboxylic acid. Santonin, in acetic acid solution, when exposed to sunlight for about a month, is converted into (colorless) photosantonic acid (C15H22O5) which is generally regarded as less toxic. The ethyl ester of the latter is obtained when an alcoholic solution of santonin is exposed to sunlight (Sestini). A yellow coloration is developed upon exposure of santonin to light. Santonin is optically levorotatory.
Proposed biosynthesis
The full biosynthesis of α-santonin has not been elucidated but α-santonin bears much similarity to parthenolide. The proposed biosynthesis begins with the cyclization of farnesyl diphosphate (FPP) to (+)-germacrene A by a sesquiterpene synthase. (+)-germacrene A hydroxylase then hydroxylates the isopropenyl side chain. The oxidation of germacratrien-12-ol to germacratrien-12-oic acid via the intermediate germacratrien-12-al is done by NADP+-dependent dehydrogenase(s). Germacratrien-12-oic acid is then hydroxylated at C6 subsequently followed by lactonization forming (+)-costunolide.
It was proposed that the methylene of (+)-Costunolide is reduced before the second ring closure. The bicyclic decalin ring system is formed via the eudesmyl cation followed by hydroxylation at C1. Further oxidation at C3 forms the β-ketohydroxyl which upon elimination of H2O completes the proposed biosynthetic pathway of α-santonin.
Photochemistry
The chemistry of α-santonin upon exposure to sunlight has the distinction of being the first reported organic photochemical reaction. Trommsdorff reported in 1834 that crystals of α-santonin first turned yellow upon exposure to sunlight before "exploding". The product of this solid-phase reaction was identified by Matsuura in 1968 as the product of photorearrangement, followed by a lattice-controlled Diels–Alder reaction and [2+2]-photocycloaddition. On the other hand, exposure to light in the solution phase results in the formation of monomeric skeletal rearrangement products. The mechanism of the photodimerization has been investigated in detail.
Historical pharmacological use
Santonin was developed in the 1830s by German chemists by extracting the chemical from Artemisia cina, a plant from Turkmenistan. At the time Artemisia was often used as an antihelminthic remedy, and as a perennial it was widely accessible. A common remedy at the time used an infusion of 5–10 g herb in 500 ml water. Castor oil could be used to help the expulsion process. It was reported that by 1843 candy lozenges were available in Germany which contained santonin.
Santonin was used from the mid-19th century to the 1950s as an anthelminthic, typically administered with a purgative. Santonin was used in treatment of infestation by the roundworm Ascaris lumbricoides and in ascarid parasitoses in general (including threadworm parasitosis). It is ineffective in treatment of tapeworm infestation.
Santonin was often found as a major ingredient of patent remedies for intestinal worms. It was sold in numerous formulations with varying degrees of effectiveness, such as worm lozenges, powders, syrups, and tonics.
It was reported by an official of the Eastern & Russian Trading Company that during 1926, Japanese manufacturers were mixing santonin into nearly all pastry, confections, and tonics as part of a government-sponsored effort to eradicate intestinal parasites; Japan at the time imported five tons of santonin from Russia annually.
Encyclopædia Britannica (1911) notes that the typical dose was 2 to 5 grams. (This was a total dose; many regimens called for three doses daily over three days, and the "three teaspoons three times a day for three days" regimen was typical around the 1950s when use of santonin was starting to wane; actual doses per dose were closer to 20–30 milligrams per adult dose in a typical "'50s regimen", but "one-shot" doses of santonin (especially via suppository) were common in the late 19th century–early 20th century.) The only formerly registered British preparation (as of 1911) was the "trochiscus santonini" (santonin lozenge), but the preparation "sodii santoninas" (soda of santonin) was also formerly listed as an official preparation in the U.S. Pharmacopoeia. Commercial preparations containing santonin (usually containing a purgative laxative as well) also appeared in US drug formularies as late as the 1950s; the Modern Drug Encyclopedia and Therapeutic Index of 1955 listed Lumbricide (produced by Massengill) and a generic santonin preparation made by Winthrop-Stearns (now Winthrop-Sanofi).
Santonin also was used in a lesser extent in treatment of atony of the bladder. This usage largely dropped off after the early 20th century.
Dosage forms varied for santonin; in the 19th–20th centuries, santonin lozenges or suppositories designed for single-dosage treatment of ascarid infestation were the typical form of treatment, whilst in the 1950s the two remaining santonin preparations on the market in the United States were liquid medications.
Hazards and difficulty of use of santonin
Santonin was an agent that (compared to more modern anthelminthic drugs) was very complicated to use and entailed rather serious risk to the patient. Nearly every formulary and herbal which lists santonin or santonin-containing plants lists the real risk of yellow vision and of fatal reactions; even small doses of santonin cause disturbances of vision, usually yellow vision or perhaps green (xanthopsia or chromatopsia). Even the Encyclopædia Britannica noted:
...These effects usually pass off in a few days. Large doses, however, produce toxic effects, aphasia, muscular tremors and epileptiform convulsions, and the disturbances of vision may go on to total blindness.
More typical is the warning given regarding side effects of santonin in King's American Dispensatory:
Santonin is an active agent, and, in improper doses, is capable of producing serious symptoms, and even death. As small a dose as 2 grains is said to have killed a weakly child of 5 years, and 5 grains produced death in about 1/2 hour in a child of the same age. Among the toxic effects may be mentioned gastric pain, pallor and coldness of the surface, followed by heat and injection of the head, tremors, dizziness, pupillary dilatation, twitching of the eyes, stertor, copious sweating, hematuria, convulsive movements, tetanic cramps stupor, and insensibility. Occasionally symptoms resembling cholera morbus have been produced, and in all cases the urine presents a characteristic yellowish or greenish-yellow hue. We have observed convulsions caused by the administration of "worm lozenges." Death from santonin is due to respiratory paralysis, and post-mortem examination revealed in one instance a contracted and empty right ventricle, and about an ounce of liquid, black blood in the left heart, an inflamed duodenum, and inflamed patches in the stomach (Kilner).
. . .
Santonin often produces a singular effect upon the vision, causing surrounding objects to appear discolored, as if they were yellow or green, and occasionally blue or red; it also imparts a yellow or green color to the urine, and a reddish-purple color if that fluid be alkaline. Prof. Giovanni was led to believe that the apparent yellow color of objects observed by the eye, when under the influence of santonin, did not depend upon an elective action on the optic nerves, but rather to the yellow color which the drug itself takes when exposed to the air. Santonin colored by the air does not produce this effect, which only follows the white article. The air gives the yellow color to santonin, to passed urine containing it, and to the serum of the blood when drawn from a vein, and, according to Giovanni, it is owing to its direct action upon the aqueous humor, where it is carried by absorption, that objects present this color. The view now held, however, is that of Rose, that the alkaline serum dissolves the santonin, which then acts upon the perspective centers of the brain, producing the chromatopsia or xanthopsia.
At least one modern herbal has also noted these same severe side effects of santonin.
Even were it not for the fact that santonin is among the most toxic of herbal anthelminthic drugs, deworming using santonin is complicated in comparison to more modern anthelminthics. Typically, santonin must be taken whilst fasting completely (both before and after taking the drug) for "single dose" regimens or on a full stomach with all fats and oils in the diet being avoided for 2–3 days before treatment as well as during treatment and 2–3 days afterwards (due to santonin being fat soluble and having an increased risk of side effects); after a course of santonin, a purgative must be given to cleanse the body of the dead worms. (The two remaining registered santonin preparations in the United States as of 1955 were in fact santonin/purgative combinations; Lumbricide contained santonin and senna (among other ingredients) and the Winthrop-Stearns generic preparation was a santonin/cascara sagrada combination drug.)
Due to the severe side effects (even when used as directed), the need for a purgative, and the development of many safer deworming drugs, santonin has largely fallen out of use. Typically mebendazole and pyrantel pamoate are used in modern pharmacopoeia practice where santonin was formerly used; even guides on holistic medicine strongly recommend avoiding the use of santonin due to its severe and occasionally fatal side effects and the availability of far safer anthelminthics . The Council Directive 65/65 European Economic
Community (EEC) (in regards to pharmaceuticals and naturopathic preparations) has officially ruled santonin preparations to have an "unacceptable" risk-benefit ratio and preparations containing santonin are no longer eligible for registration in EU countries .
Santonin and absinthe
While absinthe is certainly more infamous for its content of thujone, the liquor does also contain small amounts of santonin . It has been speculated by some parties that Impressionist art—in particular, Van Gogh's artwork—may have been inspired not by thujone and its presumed psychotropic effects, but on the "yellow vision" or xanthopsia which is a known side effect of santonin. This has been disputed, however, most notably by Arnold and Loftus (1991) who have noted the santonin content would have been insufficient to cause xanthopsia.
See also
Artemisin, a hydroxylated derivative of santonin
References
Sesquiterpene lactones
Enones
Gamma-lactones
Plant toxins
Heterocyclic compounds with 3 rings | Santonin | Chemistry | 3,116 |
1,272,166 | https://en.wikipedia.org/wiki/Castrol | Castrol Limited is a British oil company that markets industrial and automotive lubricants, offering a wide range of oil, greases and similar products for most lubrication applications. The company was originally named CC Wakefield; the name Castrol was originally just the brand name for CC Wakefield's motor oils, but the company eventually changed its name to Castrol when the product name became better-known than the original company name.
Since 2000, Castrol Limited has been a subsidiary of BP, which acquired the company for $4.73 billion.
History
The "Wakefield Oil Company" was founded by Charles Wakefield in Cheapside, London in 1899. Wakefield had previously
left a job at Vacuum Oil to start a new business selling lubricants for trains and heavy machinery.
Eight Vacuum Oil employees joined Wakefield, and the company launched its first lubricant in 1906.
In early 20th century, Wakefield Co. developed lubricants especially suited for automobiles and aeroplanes. The brand "Castrol" originated after researchers added measured amounts of castor oil (a vegetable oil derived from castor beans) to their lubricant formulations.
By 1960, the name of the motor oil had eclipsed the company's name itself so "CC Wakefield & Company" became "Castrol Limited". In 1966, Castrol was acquired by company Burmah Oil, which was renamed "Burmah-Castrol". Burmah-Castrol was purchased by London-based multinational BP (then, "BP Amoco plc") in 2000.
At the time of purchase, Burmah-Castrol had a turnover of nearly £3 billion with operating profits of £284 million. The company also had 18,000 employees worldwide, with operations in 55 countries. Respectively, BP Amoco had 80,400 employees worldwide and revenues of more than £63 billion.
While Burmah's operations folded into the group, Castrol has remained as a subsidiary of BP.
Products
Lubricants
Castrol is a leading manufacturer of lubricants and offers a broad range of products for various applications. The exact names of the product groups and types are :
Passenger car engine oils:
Edge
Magnatec
GTX
Commercial vehicle engine oils:
Vecton
RX
CRB
Automatic transmission fluids, differential and axle fluids, manual transmission fluids:
Transmax
Transynd
Syntrax
Others
Some steam locomotives were fitted with one or more Wakefield mechanical lubricators. These were normally mounted on the locomotive footplate alongside the boiler, in a position where a mechanical linkage could be made with some point on the locomotive's valve gear or another moving part. The reciprocation of this caused a lever on the lubricator to oscillate, and this was converted to a small rotary movement by a ratchet. The gradual rotation caused a small amount of lubricating oil to be fed into pipes leading to the cylinders, valves and other parts. The amount of oil fed was in proportion to the distance travelled by the locomotive in either direction.
Sponsorship
Motorsport
The brand has been involved in Formula One for many years, supplying to a number of teams, including McLaren (1979–1980 and 2017), Williams (1997–2005), Team Lotus (1992–1993), Brabham (1983–1984), Sauber (1994-early 1995), Jaguar (2002–2004), Renault/Alpine (2017–2025), Audi (2026 onwards) and Walter Wolf Racing.
Castrol has sponsored the Ford World Rally Team and M-Sport in the World Rally Championship since 2003, and the Chip Ganassi Racing Ford GT factory team from 2016, to 2019. It has also sponsored Volkswagen Motorsport activities in the Dakar Rally and later the World Rally Championship since 2005. Audi Sport's activities in rallying and touring car racing have been sponsored by Castrol, as well as its Le Mans Prototypes program since 2011. BMW Motorsport was sponsored by Castrol from 1999 to 2014.
Toyota Motorsport had Castrol sponsorship in the World Rally Championship from 1993 to 1999, and Hyundai Motorsport did so from 2000 to 2002. Also, the Honda factory team at the World Touring Car Championship had Castrol sponsorship from 2012 to 2020.
In the All-Japan Grand Touring Championship, the 1997 championship-winning TOM'S Toyota Supra (famous from the Gran Turismo series by Polyphony Digital) and later the Mugen Honda NSX had Castrol sponsorships.
In North America, Castrol has been an active sponsor of NHRA drag racing. Castrol sponsored John Force Racing under the GTX brand from 1987 until the end of the 2014 season. Also, the All American Racers had Castrol sponsorship in the CART World Series from 1996 to 1999. In 2014, Castrol sponsored former Indy 500-winning IndyCar team Bryan Herta Autosport, with English rookie Jack Hawksworth behind the wheel.
Castrol is the name sponsor of Castrol Raceway, a multi-track oval, drag, and motocross racing facility in Edmonton, Alberta, Canada. Castrol is the sponsor of D. J. Kennington in the NASCAR Canada Series and NASCAR Cup Series.
In Australia, Castrol has a long history with the Supercars category, and between 1993 and 2005, Castrol was the title sponsor of Perkins Engineering. It also sponsored Longhurst Racing between 1995 and 1999, Ford Performance Racing between 2007 and 2009, and Paul Morris Motorsport in 2010. In conjunction with a multi-year series sponsorship, between 2014 - 2016 several race events acquired Castrol naming rights including the Castrol Edge Townsville 500 and the Castrol Gold Coast 600. Castrol was the title sponsor of Team Bray, owned by Australian drag car legend, Victor Bray for 17 years.
Castrol was the main sponsor of the Castrol International Rally in Canberra for 11 years between 1976 and 1986. The same was true for an International Rally held in South Africa, ending annually in neighbouring Swaziland. It was the most prestigious event on the South African rally calendar at the time, until Castrol ended its sponsorship of this event. Later only some competitors' cars were carrying the bright green and red colours of Castrol sponsorship in national rally events, notably the S.A. Toyota dealer team.
In 2019, Castrol extended their sponsorship activities by re-forming a partnership with Jaguar, this time supporting them in Formula E and also NASCAR Cup Series giants RFK Racing-Ford since 2020 season due to Ford's commercial relationship with BP plc.
Castrol also briefly made an appearance in 1993 with Nissan in the British Touring Car Championship, where Keith O'Dor managed to win the 9th round of the season at Silverstone with his teammate Win Percy taking 2nd.
American football
Castrol advertising has been a part of telecasts of the National Football League for years. In 2011, Castrol's Edge brand became the official motor oil sponsor for the league, renewed until the 2017 season.
Cricket
The Castrol Cricket Index is a dynamic indicator of the overall performance of a cricket team. It is calculated by taking into consideration the batting momentum, the bowling efficiency, the performance of the teams in the quick start overs and the extreme performance overs and many other factors. Castrol Cricket also ranks cricketers based on their overall performance. India centric initiatives being undertaken like Castrol World Cup ka Hero was created during the 2011 Cricket World Cup.
Rugby Union
In 2011, Castrol signed a four-year sponsorship deal for the Australian national rugby union team and as the naming rights sponsor of The Rugby Championship.
Football
From 1995 until 1997, Castrol were also the shirt sponsors of English Football League side Swindon Town.
Advertising
Castrol products are still marketed under the red, white and green colour scheme that dates from the launch of Castrol motor oil in 1909. Advertisements for Castrol oil historically featured the slogan "Castrol – liquid engineering". This was more recently refreshed and reintroduced as "It's more than just oil. It's liquid engineering."
For many years, the opening notes of the second Nachtmusik movement of Mahler's Seventh Symphony were used as the signature theme of Castrol TV commercials.
Wakefield vehicles advertised the company and Castrol on their sides; models of them were made by Dinky Toys, and in later times became sought-after collectors' items. One example from 1934 to 1935, in very good to excellent condition, was estimated to fetch £1,000-£1,500 at auction in 2016.
References
External links
Automotive companies of the United States
BP subsidiaries
Chemical companies of the United States
Motor oils
British companies established in 1899
Energy companies established in 1899
Multinational companies
Oil companies of the United States
Petroleum products
British brands
1899 establishments in England | Castrol | Chemistry | 1,765 |
60,218,169 | https://en.wikipedia.org/wiki/Cell%20cycle%20withdrawal | Cell cycle withdrawal refers to the natural stoppage of cell cycle during cell division. When cells divide, there are many internal or external factors that would lead to a stoppage of division. This stoppage could be permanent or temporary, and could occur in any one of the four cycle phases (G1, S, G2 and M), depending on the status of cells or the activities they are undergoing. During the process, all cell duplication process, including mitosis, meiosis as well as DNA replication, will be paused. The mechanisms involve the proteins and DNA sequences inside cells.
Permanent cell cycle withdrawal
Permanent cell cycle withdrawal refers to the forever stoppage in divisions of cells. In organisms, cells do not divide endlessly. Certain mechanisms are present to prevent cells from indefinite division, which is mostly done by programmed failure in DNA synthesis. By adapting the above mechanism, cells are prevented from over dividing. The process also enables cells to proceed to senescence, which are further stages of cell life and growth.
Mechanism
The permanent cell cycle withdrawal is mainly done by the wearing off of DNA sequences during S Phase, the second stage during a DNA replication progress. Such progress occurs in the end sequences of the whole linear chromosome named telomeres.
Telomeres are sequences of repetitive nucleotides which serve no genetic use. During the replication process, the DNA replication enzymes are not able to copy the ending sequences at the telomere. Those sequences, located at the end of the telomere and chromosome, would hence get lost gradually. Once all of these sequences have been worn out, the useful genetic information in the cell's chromosome would also get lost. This prevents cells from cell dividing, withdrawing cells from the cell division cycle. Therefore, telomeres act as the buffer for cells to continue dividing and when telomeres are worn out, cells lose their dividing function.
Not all cells carry out cell cycle withdrawal. In some cells, such as germ cells, stem cells and white blood cells, the withdrawal process do not occur. This is to ensure that these cells continue dividing for body growth or reproduction. Such phenomena is brought about by the presence of telomerase, which would catalyse the reaction of adding nucleotide sequences to the ends of telomeres. It replenishes the telomeres that are lost during DNA replication, compensating for enough telomerase sequence so that the useful DNA content would not be damaged. This allows such cells to have continuous division. Some other cells do not have the mechanism of cell cycle withdrawal because they don't even contain the function of cell division. Red blood cells, for example, do not contain genetic material when mature, and hence will not carry out cell cycle or its withdrawal.
Some organisms also do not withdrawal mechanism. Eukaryotic organisms are such examples. The DNA structure in these organisms are in the form of circular chromosomes, meaning there would be no "ends" appearing in their DNA. Therefore, the wearing off of DNA would not occur, and the genetic information would remain the same, and no withdrawal would happen. This is to prevent the stopping of cell division in eukaryotic organisms, or even withdrawing from the basic reproduction procedures of eukaryotic cells.
Significance
There are several significance with regards to the withdrawal of cell cycle, one of which is to prevent unlimited cell division in somatic cells. This is to prevent too many cells from accumulating inside an organism's body, ensuring that cells in different organs are contained in a fixed proportion for achieving optimal function. The stoppage of exponential growth in cells also avoids cell growth diseases, such as tumours or cancer, from occurring in organism bodies. Studies have discovered the linkage between the abnormal replenishing of telomere, overactivity of telomerase, and cancer growth. Here, telomere act as a barrier against cells from dividing abnormally, hence providing a stable environment for body functions. The withdrawal process also prevents diseased cells, or cells with mutated or damaged DNA, from continuing to divide and increasing the percentage of abnormal cells inside the body. It can further allow these cells to stop their functions and differentiations to undergo a programmed cell death process called apoptosis.
Furthermore, the withdrawal process could allow cells to encounter further parts of their cell life, namely senescence and natural apoptosis. During normal body activities, cells divide, grow and differentiate into different cell types and serve different functions. The above procedures are also known as senescence. After senescence, body cells would start to become old, and several functions would be lost during the process. As these cells with limited functions are inefficient in performing body activities, they are programmed to self demolition under the presence of apoptotic signals, such as caspase proteins and Bcl-2 family regulation proteins. Before such process, the cell cycle withdrawal ensures that these aged cells are not divided into other daughter cells before death, so as to maintain the age level of cells in organisms to perform efficient body activities.
Temporary cell cycle withdrawal
Temporary cell cycle withdrawal, also known as cell cycle arrest, refers to the short-term stoppage in cell division. This mechanism often happens in organisms' bodies, mainly due to the reasons of abnormality in growth factors or the replication of DNA. In these cases, the withdrawal starts when abnormality is detected, and ends once the detected errors have been repaired. This process makes sure that cells are functioning properly after dividing, and to prevent mutations from occurring.
Mechanism
The mechanism is brought about by positive and negative regulators, and has specific checkpoints to signal cell cycle to stop. The cell cycle goes on only when a go-ahead signal was received by the checkpoints, meaning the stages of cell cycle are operating as usual.
Cyclins and cyclin-dependent kinases (CDK) are major positive regulators, and appear throughout the cell cycle. The CDK appear as positive regulators, which withdraws cells from their cycle if a certain type of cyclin is not detected in the process of cell division. Throughout the cell cycle, three cyclins, namely G1/S, S and M, would appear at different stages of the cell cycle respectively. The CDK detects the presence of these cyclins by binding with these cyclins and producing a type of target protein to move the cell cycle forward. Once the cyclins are absent, it means the previous process in cell cycle is not finished yet, and hence the cell cycle comes to a halt until the whole process is made. The detection of G1/S, S and M cyclins takes place in G1 phase, at the end of G1 phase, and at the end of G2 phase respectively.
There are two main types of negative regulators in the cell cycle that arrests the cell cycle, and has to be removed in order to resume the process. The first one is retinoblastoma protein, which prevents the cell from getting too large and to prohibit the premature transition from G1 to S phase. It functions by binding to transcription factors, for example E2F, so that the DNA could not be replicated until the cell has grown to a certain extent and the retinoblastoma protein is phosphorylated. Another type of negative regulator is p53, which halts the cell cycle process upon detection of DNA damage so as to provide to for repairing. This regulator can also induce apoptosis when the DNA damage is too large and cannot be repaired.
Checkpoints in cell cycles include DNA replication checkpoints and spindle assembly checkpoints. DNA replication checkpoints are located at the G1, S and G2 phase to check if DNA is normal, and withdraws the cell from the cycle if the DNA is damaged or has undergone incomplete replication. The spindle assembly checkpoints, on the other hand, ensure that the chromosomes in cells are segregated properly by microtubules in cells during mitotic cell division. If errors occur when the microtubules are attaching to the centromere, the centre of a chromosome, the cell cycle will halt until the error is corrected. Possible errors include microtubules not attached properly to the centromere, or chromosomes are not segregated in half.
Significance
The significance of cell cycle arrest is merely to ensure that cells do not undergo improper division. Once such a division occurs, the cell cycle automatically stops until repairs have been made, or directly proceed to the stage of apoptosis once the damage is irreparable. Like permanent cell cycle withdrawal, this mechanism is to prevent damaged cells from continuing to develop or even worse, dividing and spreading.
References
Cell cycle
Cell biology | Cell cycle withdrawal | Biology | 1,772 |
78,854,485 | https://en.wikipedia.org/wiki/Hymenochaete%20microcycla | Hymenochaete microcycla is a species of fungus in the genus Hymenochaete.
References
Hymenochaetaceae
Fungus species
Fungi described in 1844
Taxa named by Joseph-Henri Léveillé | Hymenochaete microcycla | Biology | 47 |
6,428,331 | https://en.wikipedia.org/wiki/Disease%20informatics | Disease Informatics (also known as infectious disease informatics) studies the knowledge production, sharing, modeling, and management of infectious diseases. It became a more studied field as a by-product of the rapid increases in the amount of biomedical and clinical data widely available, and to meet the demands for useful data analyses of such data.
Considering infectious diseases contribute to millions of deaths every year, the ability to identify and understand disease diffusion is crucial for society to apply control and prevention measures. The knowledge gained by researchers in the field of disease informatics can be used to aid policymakers' decisions on issues such as spreading public awareness, updating the training of health professionals, and buying vaccines.
Aside from aiding in policymakers' decisions, the goals of disease informatics also include increased identification of biomarkers for transmissibility, improved vaccine design, and a deeper understanding of host-pathogen interactions, and the optimization of antimicrobial development.
Methods
Artificial intelligence
The use of artificial intelligence (AI) tools, such as machine learning and natural language processing (NLP), in disease informatics increase efficiency by automating and speeding up several data analysis processes. Advances with AI and increased accessibility of data aid in predictive modeling and public health surveillance. AI uses predictive modeling to examine vast data sets and forecast future outcomes to increase the ability to predict disease outbreaks and help guide public health treatments. AI also provides a valuable avenue by combining its ability of spatial modeling with geographic information system (GIS) data to uncover geographical patterns (for example disease clusters) to support data-driven decision-making for local-level predictions of disease diffusion. As the growth of AI continues, more advances for its use in disease informatics are expected to come.
Machine learning
Machine learning (ML) techniques aid the study of disease informatics with its capability to spatially and temporally predict the progression and transmission of infectious diseases. In disease informatics, ML algorithms are used to analyze extensive amounts of complex data sets to identify patterns across varying types of data such as demographics, electronic health records, environmental conditions, etc. The types of ML techniques commonly used are decision trees (decision tree model), random forests, support vector machines (support vector machine), and deep learning networks (deep learning). Using these tools, researchers can apply them to data sets (for example genomic data, social media posts, and health records) to make predictions about the potential sources of an outbreak, the likelihood of an individual contracting a certain disease, and forecasting the number of cases of a disease in a given region. ML models have proven to be just as accurate as traditional statistical methods (especially when multiple ML models are used concurrently) when it comes to predicting the spread and onset of diseases, according to numerous studies.
Text mining
The use of text mining has become a beneficial avenue for querying large amounts of data to aid in gene mapping and the analysis of genomes. This tool provides the ability to query medical databases for processes such as genomic mapping, by integrating the genomic and proteomic data to map the genes and highlight their interrelationships with various diseases. Retrieving data of targeted sequences can be done in two ways, through a similarity search or by keyword search. A similarity search (using software like BLAST (biotechnology) is performed by entering a known sequence as a query sequence to search for sequences that have similarities. A keyword search (public tools include SRS, Entrez, and ACNUC) uses annotations that define the features of genes, such as sequence positions, to retrieve the desired gene sequences being searched for.
Syndromic Surveillance
Through a process called syndromic surveillance (related to public health surveillance) data analysis methods can be successfully used to predict potential disease outbreaks by detecting timely, pre-diagnosis health indicators. Syndromic surveillance combines demographic data (age, gender, ethnicity, etc.) with patient visit data (admission status, chief complaint, type of office visit, etc.) that can be put through natural language processes to highlight potential predictors of an outbreak. Due to the time-sensitivity in predicting possible outbreaks, the use of chief complaint data is valuable as it is available much more quickly than formal diagnosis data from physicians' offices. The key to successfully harnessing surveillance data for disease informatics is to use more than one source. Other important sources that are commonly used synchronically include the following:
Over-the-counter drug (OTC) sales
Hospital admissions
Absenteeism rates from schools and workplaces
Lab test orders
Poison control centers' communications
Case report numbers
Limitations and future prospects
Accessibility concerns
The accuracy of these AI tools and techniques relies upon providing them with high-quality, comprehensive data. Accessibility and collection of such data is still an ongoing challenge because most of the data pulled is incomplete, noisy, and contains human errors (i.e. grammar, abbreviations, spelling) which means the data must undergo a thorough cleaning (data cleansing) before it is eligible to be used.
The data collected will also come from numerous sources (due to differences in data availability and governance) that use varying formatting and software, creating an issue of needing some form of standardized infrastructure to better integrate and manage data. The formation of a standardized taxonomy for data analysis and predictive modeling would facilitate research collaboration, accelerate decisions, and help select the right predictive models to be used.
One method being used is federated learning, which allows the AI to be trained across multiple different centers without the need for sharing raw data, keeping the data safe within its source. However, the same issues of different formatting and software to ensure model convergence still affect this approach as well, so algorithmic improvements are needed.
Another concern is the potential for bias and overfitting of the predictive models, which could lead to inaccurate predictions. Human error can still persist even using these tools to automate tasks, due to the fact that if the AI tools are trained incorrectly, they will produce inaccurate data. A relevant study suggests that implementing AI with wearable devices and other emerging technology in the future would benefit some of the challenges by providing real-time data for the models to use, which could lead to increased accuracy of the data in its raw form, creating less need to spend time cleaning the data, and allowing the models to make more accurate predictions.
Ethical concerns
A critical concern for using AI and predictive modeling in disease informatics is data security and privacy. The data sources being used (electronic health records, demographics, etc.) contain highly sensitive information that must be protected for all parties involved. Any models or techniques being used need to be in compliance with local governmental regulations and laws such as HIPAA in the United States. The data used must also undergo rigorous data anonymization and de-identification protocols to protect patient privacy.
Through the further use and growth of explainable AI, also referred to as XAI, (explainable artificial intelligence) researchers and all parties involved can ensure transparency and accountability when it comes to using data analysis and computational methods in the field of disease informatics. XAI provides explanations of how the algorithms being used work, why they were chosen, what knowledge they produce, and so on.
References
Health informatics
Computational fields of study | Disease informatics | Technology,Biology | 1,473 |
57,190,596 | https://en.wikipedia.org/wiki/Eline%20Tolstoy | Eline Tolstoy, born in 1965, is a distinguished Dutch astronomer recognized for her significant contributions to understanding the formation and evolution of dwarf galaxies through the study of their resolved stellar populations. Educated at the University of Edinburgh and the University of Groningen, where she received her doctorate in 1995, Tolstoy has held postdoctoral positions in Germany and at Oxford University.
Since 2001, she has been affiliated with the University of Groningen, becoming a full professor at the Kapteyn Institute in 2011. Tolstoy's work, which she describes as 'Galactic Palaeontology', aims to shed light on the broader cosmological processes involved in galaxy formation and evolution. Her leadership role in the MICADO instrument project for the European Extremely Large Telescope underscores her prominent position in the field. Tolstoy's excellence in research and teaching has been recognized with several awards, including the 2006 Lecturer of the Year at the Faculty of Mathematics and Natural Sciences in Groningen and the 2007 Pastoor Schmeitsprijs.
Life and education
Tolstoy grew up in Scotland and gained a BSc (Hons) from the University of Edinburgh in 1988. She studied at Leiden University (doctoral, 1990) and then in 1995, she received her doctorate from the University of Groningen, under the supervision of A. Saha, Piet van der Kruit and Harvey Butcher. The title of her thesis was `Modeling the resolved stellar populations of nearby dwarf galaxies'.
Post-doctorate career
She worked as an ESA Postdoctoral Fellow, at ST-ECF Garching, Germany (1996–1998), followed by an ESO postdoctoral fellowship, Garching, Germany (1998–2000). She spent a year at Oxford University as Gemini Support Scientist.
She has been working at the University of Groningen since 2001. In 2007, she received a Vici grant from the Netherlands Organization for Scientific Research. She has been a full professor at the Kapteyn Institute of the University of Groningen since 2011.
Tolstoy is the Dutch project leader for the MICADO instrument that accompanies the European Extremely Large Telescope.
Research interests
Her research interests centre mainly on understanding the formation and evolution of small dwarf galaxies by studying their resolved stellar populations. She is interested to discover what these systems can tell us about larger galaxies and their internal processes and also the clues that they may provide to our cosmological understanding of galaxy formation and evolution; right from the earliest phases up to the present day. This is often called ‘Local Group Cosmology’, or ‘Stellar Archaeology. Tolstoy prefers the term ‘Galactic Palaeontology’
Awards
She was the 2006 Lecturer of the Year of the Faculty of Mathematics and Natural Sciences in Groningen
She won the 2007 Pastoor Schmeitsprijs, simultaneously with Simon Portegies Zwart.
She gave the 2013 Royal Astronomical Society George Darwin Lecture with the title 'Galactic Archaeology.’
References
1965 births
Living people
20th-century Dutch astronomers
21st-century Dutch astronomers
Alumni of the University of Edinburgh
Leiden University alumni
University of Groningen alumni
Academic staff of the University of Groningen
Women astronomers | Eline Tolstoy | Astronomy | 628 |
1,784,516 | https://en.wikipedia.org/wiki/Emission%20intensity | An emission intensity (also carbon intensity or C.I.) is the emission rate of a given pollutant relative to the intensity of a specific activity, or an industrial production process; for example grams of carbon dioxide released per megajoule of energy produced, or the ratio of greenhouse gas emissions produced to gross domestic product (GDP). Emission intensities are used to derive estimates of air pollutant or greenhouse gas emissions based on the amount of fuel combusted, the number of animals in animal husbandry, on industrial production levels, distances traveled or similar activity data. Emission intensities may also be used to compare the environmental impact of different fuels or activities. In some case the related terms emission factor and carbon intensity are used interchangeably. The jargon used can be different, for different fields/industrial sectors; normally the term "carbon" excludes other pollutants, such as particulate emissions. One commonly used figure is carbon intensity per kilowatt-hour (CIPK), which is used to compare emissions from different sources of electrical power.
Methodologies
Different methodologies can be used to assess the carbon intensity of a process. Among the most used methodologies there are:
The whole life-cycle assessment (LCA): this includes not only the carbon emissions due to a specific process, but also those due to the production and end-of-life of materials, plants and machineries used for the considered process. This is a quite complex method, requiring a big set of variables.
The well-to-wheels (WTW), commonly used in the Energy and Transport sectors: this is a simplified LCA considering the emissions of the process itself, the emissions due to the extraction and refining of the material (or fuel) used in the process (also "Upstream emissions"), but excluding the emissions due to the production and end-of-life of plants and machineries. This methodology is used, in the US, by the GREET model and in Europe in the JEC WTW .
WTW-LCA hybrid methods, trying to fill in the gap between the WTW and LCA methods. In example, for an Electric Vehicle, an hybrid method considering also the GHG due to the manufacturing and the end of life of the battery gives GHG emissions 10–13% higher, compared to the WTW
Methods not considering LCA aspects but only the emissions occurring during a specific process; i.e. just the combustion of a fuel in a power plant, without considering the Upstream emissions.
Different calculation methods can lead to different results. The results can largely vary also for different geographic regions and timeframes (see, in example, how C.I. of electricity varies, for different European countries, and how varied in a few years: from 2009 to 2013 the C.I. of electricity in the European Union fell on average by 20%, So while comparing different values of Carbon Intensity it is important to correctly consider all the boundary conditions (or initial hypotheses) considered for the calculations. For example, Chinese oil fields emit between 1.5 and more than 40 g of CO2e per MJ with about 90% of all fields emitting 1.5–13.5 g CO2e. Such highly skewed carbon intensity patterns necessitate disaggregation of seemingly homogeneous emission activities and proper consideration of many factors for understanding.
Estimating emissions
Emission factors assume a linear relation between the intensity of the activity and the emission resulting from this activity:
Emissionpollutant = Activity * Emission Factorpollutant
Intensities are also used in projecting possible future scenarios such as those used in the IPCC assessments, along with projected future changes in population, economic activity and energy technologies. The interrelations of these variables is treated under the so-called Kaya identity.
The level of uncertainty of the resulting estimates depends significantly on the source category and the pollutant. Some examples:
Carbon dioxide (CO2) emissions from the combustion of fuel can be estimated with a high degree of certainty regardless of how the fuel is used as these emissions depend almost exclusively on the carbon content of the fuel, which is generally known with a high degree of precision. The same is true for sulphur dioxide (SO2), since sulphur contents of fuels are also generally well known. Both carbon and sulphur are almost completely oxidized during combustion and all carbon and sulphur atoms in the fuel will be present in the flue gases as CO2 and SO2 respectively.
In contrast, the levels of other air pollutants and non-CO2 greenhouse gas emissions from combustion depend on the precise technology applied when fuel is combusted. These emissions are basically caused by either incomplete combustion of a small fraction of the fuel (carbon monoxide, methane, non-methane volatile organic compounds) or by complicated chemical and physical processes during the combustion and in the smoke stack or tailpipe. Examples of these are particulates, NOx, a mixture of nitric oxide, NO, and nitrogen dioxide, NO2).
Nitrous oxide (N2O) emissions from agricultural soils are highly uncertain because they depend very much on both the exact conditions of the soil, the application of fertilizers and meteorological conditions.
Electric generation
A literature review of numerous total life cycle energy sources emissions per unit of electricity generated, conducted by the Intergovernmental Panel on Climate Change in 2011, found that the emission value, that fell within the 50th percentile of all total life cycle emissions studies were as follows.
Note: 3.6 MJ = megajoule(s) == 1 kW·h = kilowatt-hour(s), thus 1 g/MJ = 3.6 g/kW·h.
Legend: , , , , , , , , .
Carbon intensity of regions
The following tables show carbon intensity of GDP in market exchange rates (MER) and purchasing power parities (PPP). Units are metric tons of carbon dioxide per thousand year 2005 US dollars. Data are taken from the US Energy Information Administration. Annual data between 1980 and 2009 are averaged over three decades: 1980–89, 1990–99, and 2000–09.
In 2009 CO2 intensity of GDP in the OECD countries reduced by 2.9% and amounted to 0.33 kCO2/$05p in the OECD countries. ("$05p" = 2005 US dollars, using purchasing power parities). The USA posted a higher ratio of 0.41 kCO2/$05p while Europe showed the largest drop in CO2 intensity compared to the previous year (−3.7%). CO2 intensity continued to be roughly higher in non-OECD countries. Despite a slight improvement, China continued to post a high CO2 intensity (0.81 kCO2/$05p). CO2 intensity in Asia rose by 2% during 2009 since energy consumption continued to develop at a strong pace. Important ratios were also observed in countries in CIS and the Middle East.
Carbon intensity in Europe
Total CO2 emissions from energy use were 5% below their 1990 level in 2007. Over the period 1990–2007, CO2 emissions from energy use have decreased on average by 0.3%/year although the economic activity (GDP) increased by 2.3%/year. After dropping until 1994 (−1.6%/year), the CO2 emissions have increased steadily (0.4%/year on average) until 2003 and decreased slowly again since (on average by 0.6%/year). Total CO2 emissions per capita decreased from 8.7 t in 1990 to 7.8 t in 2007, that is to say a decrease by 10%.
Almost 40% of the reduction in CO2 intensity is due to increased use of energy carriers with lower emission factors.
Total CO2 emissions per unit of GDP, the “CO2 intensity”, decreased more rapidly than energy intensity: by 2.3%/year and 1.4%/year, respectively, on average between 1990 and 2007.
However, while the reports from 2007 suggest that the CO2 emissions are going down recent studies find that the global emissions are rapidly escalating. According to the Climate Change 2022 Mitigation of Climate Change report, conducted by the IPCC, it states that it 2019 the world emissions output was 59 gigatonnes. This shows that global emissions has grown rapidly, increasing by about 2.1% each year compared from the previous decade.
The Commodity Exchange Bratislava (CEB) has calculated carbon intensity for Voluntary Emissions Reduction projects carbon intensity in 2012 to be 0.343 tn/MWh.
According to data from the European Commission, in order to achieve the EU goal of decreasing greenhouse gas emissions by at least 55% by 2030 compared to 1990, EU-based energy investment has to double from the previous decade to more than €400 billion annually this decade. This includes the roughly €300 billion in yearly investment required for energy efficiency and the roughly €120 billion required for power networks and renewable energy facilities.
Emission factors for greenhouse gas inventory reporting
One of the most important uses of emission factors is for the reporting of national greenhouse gas inventories under the United Nations Framework Convention on Climate Change (UNFCCC). The so-called Annex I Parties to the UNFCCC have to annually report their national total emissions of greenhouse gases in a formalized reporting format, defining the source categories and fuels that must be included.
The UNFCCC has accepted the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories, developed and published by the Intergovernmental Panel on Climate Change (IPCC) as the emission estimation methods that must be used by the parties to the convention to ensure transparency, completeness, consistency, comparability and accuracy of the national greenhouse gas inventories. These IPCC Guidelines are the primary source for default emission factors. Recently IPCC has published the 2006 IPCC Guidelines for National Greenhouse Gas Inventories. These and many more greenhouse gas emission factors can be found on IPCC's Emission Factor Database. Commercially applicable organisational greenhouse gas emission factors can be found on the search engine, EmissionFactors.com.
Particularly for non-CO2e emissions, there is often a high degree of uncertainty associated with these emission factors when applied to individual countries. In general, the use of country-specific emission factors would provide more accurate estimates of emissions than the use of the default emission factors. According to the IPCC, if an activity is a major source of emissions for a country ('key source'), it is 'good practice' to develop a country-specific emission factor for that activity.
Emission factors for air pollutant inventory reporting
The United Nations Economic Commission for Europe and the EU National Emission Ceilings Directive (2016) require countries to produce annual National Air Pollution Emission Inventories under the provisions of the Convention on Long-Range Transboundary Air Pollution (CLRTAP).
The European Monitoring and Evaluation Programme (EMEP) Task Force of the European Environment Agency has developed methods to estimate emissions and the associated emission factors for air pollutants, which have been published in the EMEP/CORINAIR Emission Inventory Guidebook on Emission Inventories and Projections TFEIP.
Intensity targets
Coal, being mostly carbon, emits a lot of when burnt: it has a high emission intensity. Natural gas, being methane (), has 4 hydrogen atoms to burn for each one of carbon and thus has medium emission intensity.
Sources of emission factors
Greenhouse gases
2006 IPCC Guidelines for National Greenhouse Gas Inventories
Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories (reference manual).
IPCC Emission Factor Database
National Inventory Report: Greenhouse Gas Sources and Sinks in Canada.
United Kingdom's emission factor database.
Air pollutants
AP 42, Compilation of Air Pollutant Emission Factors US Environmental Protection Agency
EMEP/CORIMAIR 2007 Emission Inventory Guidebook.
Fugitive emissions leaks from ethylene and other chemical plants.
Well-to-refinery carbon intensity (CI) of all major active oil fields globally
In an August 31, 2018 article by Masnadi et al. which was published by Science, the authors used "open-source oil-sector CI modeling tools" to "model well-to-refinery carbon intensity (CI) of all major active oil fields globally—and to identify major drivers of these emissions." They compared 90 countries with the highest crude oil footprint. The Science study, which was conducted by Stanford University found that Canadian crude oil is the "fourth-most greenhouse gas (GHG) intensive in the world" behind Algeria, Venezuela and Cameroon.
See also
Air pollution
AP 42 Compilation of Air Pollutant Emission Factors
Carbon footprint
Emission inventory
Energy intensity
Greenhouse gas and Greenhouse effect
IPCC list of greenhouse gases
Kaya identity
List of countries by carbon intensity of GDP
Low-carbon economy
Low-carbon fuel standard
Mobile emission reduction credit
Radiative forcing
Resource intensity
Spheroidal carbonaceous particles
Vehicle emission standard
References
External links
Washington Post article with an example of change in carbon intensity
A Note On Variations in UK Grid Electricity CO2e Intensity with Time
IPCC Special Report on Emissions Scenarios
Statistical Energy Review 2012
World Energy Council:Odyssee Database
International Energy Agency: CO2 emissions from fuel combustion
Electricity carbon intensity in European Member States: Impacts on GHG emissions of electric vehicles
A hybrid LCA-WTW method to assess the carbon footprint of electric vehicles
Carbon emissions intensity from different regions
Air pollution emissions
Atmospheric dispersion modeling
Industrial emissions control
Environmental engineering
Energy economics
Greenhouse gas emissions | Emission intensity | Chemistry,Engineering,Environmental_science | 2,783 |
44,632,637 | https://en.wikipedia.org/wiki/Psilocybe%20keralensis | Psilocybe keralensis is a species of psilocybin mushroom in the family Hymenogastraceae. It contains the compounds psilocybin and psilocin. Psilocybe keralensis is known only from Kerala, India. It is in the Psilocybe fagicola complex with Psilocybe fagicola, Psilocybe oaxacana, Psilocybe banderillensis, Psilocybe columbiana, Psilocybe herrerae, Psilocybe neoxalapensis, and Psilocybe teofiloi.
See also
List of psilocybin mushrooms
List of Psilocybe species
References
Entheogens
Fungi described in 2002
Psychoactive fungi
keralensis
Psychedelic tryptamine carriers
Fungi of Asia
Fungi of India
Taxa named by Gastón Guzmán
Fungus species | Psilocybe keralensis | Biology | 176 |
17,016,005 | https://en.wikipedia.org/wiki/Osman%20Ya%C5%9Far | Osman Yaşar () is Empire Innovation Professor at the Computational Science (CPS) department at State University of New York (SUNY) College at Brockport. He holds 3 master's degrees (physics, nuclear engineering, computer sciences) and a Ph.D. degree (engineering physics). His area of interest is supercomputing applications, computational fluid and particle dynamics, engine combustion modeling, parallel computing, plasma and radiation hydrodynamics, and adaptive mesh refinement. He established the first undergraduate program in computational science in the United States. He also established computational approach to math, science, and technology (C-MST) as a pedagogy at K-12 level. Dr. Yaşar testified before U.S. Congress about his efforts in improving math and science education.
He works closely with the industry, including General Motors, Chrysler, Cummins Engine, Intel, and Lockheed Martin. He served as the President of the Intel Supercomputer Users Group. He made important contributions in the field of science, engineering, and education. As a plasma physicist, he tackled the field of ignition in the combustion (mechanical engineering) community with more accurate models and as a computer scientist he developed algorithms to run record-breaking simulations on particle and fluid systems on supercomputers. Dr. Yaşar has more than 70 publications, developed more than 12 industrial codes, and served as Guest Editor for a number of Special Issues in his field.
Notes
References
C. D. Swanson, Computational Science Education Survey, Krell Institute
O. Yaşar, L. Little, R. Tuzun, K. Rajasethupathy, J. Maliekal, and M. Tahar, “Computational Math, Science, and Technology: A Strategy to Improve STEM Workforce and Pedagogy to Improve Math and Science Education,” Lecture Notes in Computer Science, Vol. 3992 (2006), pp. 169–176.
O. Yaşar, J. Maliekal, L. J. Little, and D. Jones, “Computational Technology Approach to Math and Science Education,” IEEE Comp. in Science and Eng., 8 (3), 76 (2006)
H. Dag, et al., “Computational Science and Engineering Education at Istanbul Technical University,” IEEE Comp. in Science and Eng., 7 (1), (2005).
O. Yaşar, “CMST Pedagogical Approach to Math and Science Education,” Lecture Notes in Computer Science, Vol. 3045 (2004), pp. 807–816.
O. Yaşar and R. Landau, Elements of Computational Science and Engineering Education, SIAM Review, 45 (2003), pp. 787–805.
O. Yaşar, “Computational Science Education: Standards, Learning Outcomes and Assessment,” Lecture Notes in Computer Science, Vol. 2073 (2001), pp. 1159–1169.
O. Yaşar, K. Rajasethupathy, R. Tuzun, A. McCoy, and J. Harkin (2000). A New Perspective on Computational Science Education, IEEE J. Comp. in Science & Engineering, 5 (2), 2000.
L. J. Little, “The computational science major at SUNY Brockport”, FGCS 19, 1285-1292 (2003).
State University of New York faculty
American computer scientists
Living people
American academics of Turkish descent
Computational physicists
Year of birth missing (living people) | Osman Yaşar | Physics | 723 |
39,116,569 | https://en.wikipedia.org/wiki/Adaptive%20fluid-infused%20porous%20film | Adaptive fluid-infused porous films change states when stretched, allowing for dynamic control over transparency and wettability. They were developed by researchers at Harvard University. The same team previously invented Slippery Liquid Infused Porous Surfaces (SLIPS) which served as the base technology to control wettability in Adaptive fluid-infused porous film.
Description
The material is a thin elastic film that contains nano-sized pores. When in a normal relaxed state, if droplets of liquid are applied to the film, they will roll freely along the smooth surface. However, when the film is stretched, any droplets of liquid that are applied to the film will be held in place on the film. If the tension on the film is later released, the film will return to its normal relaxed state, and the droplet will again move along the smooth surface. The film also becomes more transparent when stretched, allowing the material to be dynamically controlled with regards to both the wettability and transparency of the material.
References
Synthetic materials | Adaptive fluid-infused porous film | Physics,Chemistry | 203 |
5,121,057 | https://en.wikipedia.org/wiki/List%20of%20Canadian%20plants%20by%20genus | Below is a list of Canadian plants by genus. Due to the vastness of Canada's biodiversity, this page is divided.
Many of the plants seen in Canada are introduced by either intentionally or accidentally. N indicated native and X indicated exotic. Those plants whose status is unknown are marked with a ?.
A | B | C | D | E | F | G | H | I J K | L | M | N | O | P Q | R | S | T | U V W | X Y Z
Ab
Abies
N Abies amabilis – Pacific silver fir, amabilis fir
N Abies balsamea – balsam fir
N Abies grandis – grand fir
N Abies lasiocarpa – subalpine fir
Abutilon
X Abutilon theophrasti – velvetleaf, butterprint, Indian mallow
Ac
Acalypha
N Acalypha virginica – Virginia copperleaf, Virginia threeseed mercury
Acanthospermum
X Acanthospermum hispidum – hispid greenstripe
Acer
X Acer campestre – hedge maple, field maple
X Acer ginnala – Amur maple, ginnala maple
N Acer negundo – Manitoba maple, box-elder, ashleaf maple
N Acer nigrum – black maple, black sugar maple, rock maple
N Acer pensylvanicum – striped maple, moose maple, goosefoot maple
X Acer platanoides – Norway maple, Schwedler maple, crimson king maple
X Acer pseudoplatanus – sycamore maple, Scottish maple, great maple
N Acer rubrum – red maple, swamp maple, scarlet maple
N Acer saccharinum – silver maple, soft maple, white maple, silverleaf maple, river maple
N Acer saccharum – sugar maple, hard maple
N Acer spicatum – mountain maple
N Acer × freemanii (A. rubrum × A. saccharinum) – Freeman's maple
Achillea
X Achillea filipendulina – fernleaf yarrow
N Achillea millefolium subsp. borealis – northern yarrow
N Achillea millefolium subsp. lanulosa – woolly yarrow
X Achillea millefolium subsp. millefolium – common yarrow, milfoil
X Achillea ptarmica – false sneezewort, white tansy, sneezewort yarrow, pearl yarrow
N Achillea sibirica – Siberian yarrow, many-flowered yarrow
Aconitum
X Aconitum napellus – garden monk's-hood, helmet flower, Venus' chariot, aconite
X Aconitum variegatum – Manchurian monk's-hood
X Aconitum × bicolor (A. napellus × A. variegatum) – hybrid monk's-hood, two-coloured wolf's-bane
Acorus
N Acorus americanus – sweetflag
X Acorus calamus – European sweetflag
Acroptilon
X Acroptilon repens – Russian knapweed
Actaea
N Actaea pachypoda – white baneberry, doll's-eyes
N Actaea rubra – red baneberry
N Actaea × ludovici (A. pachypoda × A. rubra) – hybrid baneberry
Ad
Adenocaulon
N Adenocaulon bicolor – trail-plant
Adiantum
N Adiantum aleuticum – western maidenhair fern
N Adiantum capillus-veneris – southern maidenhair fern
N Adiantum pedatum – northern maidenhair fern, five-finger fern
N Adiantum viridimontanum – Green Mountain maidenhair fern
Adlumia
N Adlumia fungosa – Allegheny vine, climbing fumitory
Adonis
X Adonis annua – pheasant's-eye
Adoxa
N Adoxa moschatellina – moschatel, muskroot, townhall clock
Ae
Aegopodium
X Aegopodium podagraria – goutweed, snow-on-the-mountain, goat's-foot, ground elder, bishop's weed
Aesculus
N Aesculus glabra – Ohio buckeye, fœtid buckeye
X Aesculus hippocastanum – common horsechestnut
Aethusa
X Aethusa cynapium – fool's-parsley
Ag
Agalinis
N Agalinis gattingeri – Gattinger's agalinis Endangered
N Agalinis paupercula – small-flowered purple false-foxglove, small-flowered agalinis
N Agalinis purpurea – purple false foxglove, large purple agalinis
N Agalinis skinneriana – Skinner's agalinis Endangered
N Agalinis tenuifolia – slenderleaf purple false foxglove, slenderleaf agalinis
Agastache
N Agastache foeniculum – anise hyssop, blue giant hyssop
N Agastache nepetoides – yellow giant hyssop
N Agastache scrophulariifolia – purple giant hyssop
Agoseris
N Agoseris glauca – pale false-dandelion, prairie agoseris, pale agoseris, pale goat-chicory, large-flowered false-dandelion
Agrimonia
X Agrimonia eupatoria – medicinal agrimony, church steeples, European groovebur
N Agrimonia gryposepala – tall hairy agrimony, tall hairy groovebur
N Agrimonia parviflora – smallflower groovebur, harvestlice agrimony
N Agrimonia pubescens – soft groovebur, soft agrimony
N Agrimonia striata – woodland agrimony, grooved agrimony
Agropyron
X Agropyron cristatum – crested wheatgrass
Agrostemma
X Agrostemma githago – common corncockle
Agrostis
? Agrostis canina – brown bentgrass
X Agrostis capillaris – colonial bentgrass, browntop, Prince Edward Island bentgrass, Rhode Island bentgrass
X Agrostis gigantea – black bentgrass, redtop
N Agrostis hyemalis – winter bentgrass, ticklegrass
N Agrostis mertensii – northern bentgrass
N Agrostis perennans – upland bentgrass, perennial bentgrass
N Agrostis scabra – rough bentgrass, tickle grass, rough hairgrass, twin bentgrass
N Agrostis stolonifera – creeping bentgrass, spreading bentgrass
Ai
Ailanthus
X Ailanthus altissima – tree-of-Heaven, Chinese sumac, stinktree, varnish tree
Aj
Ajuga
X Ajuga genevensis – Geneva bugleweed
X Ajuga reptans – carpet bugleweed, common bugle, creeping bugleweed
Al
Alcea
X Alcea pallida – pale hollyhock
X Alcea rosea – hollyhock
Alchemilla
X Alchemilla filicaulis – thin-stemmed lady's-mantle
X Alchemilla monticola – hairy lady's-mantle
Aletris
N Aletris farinosa – colicroot Threatened
Alisma
N Alisma gramineum – grass-leaved water-plantain
N Alisma subcordatum – southern water-plantain
N Alisma triviale – northern water-plantain
Alliaria
X Alliaria petiolata – garlic mustard, hedge garlic
Allium
N Allium burdickii – narrow-leaved wild leek
N Allium canadense – Canada wild onion, meadow garlic, meadow onion
N Allium cernuum – nodding onion
X Allium oleraceum – wild garlic
X Allium sativum – garlic
X Allium schoenoprasum var. schoenoprasum – chives
N Allium schoenoprasum var. sibiricum – Siberian chives
N Allium stellatum – prairie onion, wild onion
N Allium tricoccum – wild leek, small wild leek, ramps
X Allium vineale – field garlic
Alnus
X Alnus glutinosa – black alder, European alder
N Alnus incana – grey alder, white alder, hoary alder, speckled alder
N Alnus viridis – green alder, mountain alder, American green alder, Siberian alder, Sitka alder
Alopecurus
N Alopecurus aequalis – shortawn foxtail
N Alopecurus alpinus – alpine foxtail
X Alopecurus geniculatus – water foxtail
X Alopecurus pratensis – meadow foxtail
Althaea
X Althaea hirsuta – hairy marsh-mallow
X Althaea officinalis – common marsh-mallow
Alyssum
X Alyssum alyssoides – pale alyssum, small alyssum, yellow alyssum, pale madwort
X Alyssum murale – yellow-tuft
Am
Amaranthus
X Amaranthus albus – white tumbleweed, tumble pigweed, tumbleweed amaranth
X Amaranthus blitoides – prostrate amaranth, prostrate pigweed, matweed
X Amaranthus blitum – purple amaranth
X Amaranthus cruentus – blood amaranth, purple amaranth, red amaranth, caterpillar amaranth, African spinach
X Amaranthus hybridus – smooth amaranth, hybrid amaranth, green pigweed, smooth pigweed, green amaranth
X Amaranthus palmeri – Palmer's amaranth
X Amaranthus powellii – green amaranth, Powell's smooth amaranth
X Amaranthus retroflexus – redroot amaranth, redroot pigweed, wild-beet amaranth, rough pigweed
X Amaranthus spinosus – spiny amaranth
N Amaranthus tuberculatus – roughfruit amaranth, roughfruit waterhemp, tall waterhemp, tall pigweed
Ambrosia
N Ambrosia artemisiifolia – common ragweed, annual ragweed, annual bur-sage
N Ambrosia psilostachya – perennial ragweed, western ragweed, naked-spike ambrosia, Cuman ragweed
N Ambrosia trifida – giant ragweed, great ragweed, buffalo-weed, skeleton-leaf bur-sage
Amelanchier
N Amelanchier alnifolia – Saskatoonberry, northwestern serviceberry
N Amelanchier arborea – downy serviceberry, downy juneberry, common serviceberry
N Amelanchier bartramiana – mountain juneberry, Bartram's shadbush, Bartram's chuckleypear
N Amelanchier canadensis – Canada serviceberry, swamp shadbush, thicket serviceberry
N Amelanchier humilis – low serviceberry, running serviceberry
N Amelanchier laevis – smooth juneberry, Allegheny serviceberry, smooth chuckleypear
N Amelanchier sanguinea var. gaspensis – Gaspé roundleaf juneberry
N Amelanchier sanguinea var. sanguinea – roundleaf juneberry, roundleaf serviceberry, Fernald's chuckleypear
N Amelanchier stolonifera – running serviceberry, running juneberry, running chuckleypear
N Amelanchier × intermedia (A. arborea × A. canadensis) – swamp sugarpear
N Amelanchier × neglecta (A. bartramiana × A. laevis) – hybrid juneberry
N Amelanchier × quinti-martii (A. arborea × A. bartramiana) – Quint-mart's serviceberry
N Amelanchier × wiegandii (A. arborea × A. sanguinea) – Wiegand's serviceberry
Amerorchis
N Amerorchis rotundifolia – small roundleaf orchis, oneleaf orchid
Ammannia
N Ammannia robusta – scarlet ammannia Endangered
Ammophila
N Ammophila breviligulata – American beachgrass
Amorpha
N Amorpha canescens – leadplant, downy indigobush
N Amorpha fruticosa – false indigo
Amphicarpaea
N Amphicarpaea bracteata – American hog-peanut
An
Anagallis
X Anagallis arvensis – scarlet pimpernel
Anaphalis
N Anaphalis margaritacea – pearly everlasting
Anchusa
X Anchusa arvensis – small bugloss, annual bugloss, alkanet
X Anchusa officinalis – common bugloss
Andromeda
N Andromeda glaucophylla – bog rosemary, rosemary-leaf marsh andromeda
N Andromeda polifolia var. jamesiana – James Bay bog rosemary
N Andromeda polifolia var. polifolia – northern bog rosemary, marsh holyrose
Andropogon
N Andropogon gerardii – big bluestem, turkeyfoot
N Andropogon virginicus – broom-sedge
Androsace
? Androsace occidentalis – western rock-jasmine
N Androsace septentrionalis – pygmy-flower rock-jasmine, northern androsace
Anemone
N Anemone acutiloba – sharp-lobed hepatica, sharp-lobed liverleaf
N Anemone americana – round-lobed hepatica, American liverleaf
X Anemone blanda
N Anemone canadensis – Canada anemone, roundleaf thimbleweed
N Anemone cylindrica – long-fruited anemone, thimbleweed, candle anemone, long-headed anemone
N Anemone multifida – cutleaf anemone, cliff anemone, early anemone
N Anemone parviflora – northern anemone, small-flowered anemone
N Anemone patens – pasqueflower, prairie smoke, prairie crocus, cutleaf anemone
N Anemone quinquefolia – wood anemone, snow-drops
N Anemone richardsonii – Richardson's anemone, yellow anemone
N Anemone virginiana – tall thimbleweed, riverbank anemone
Anethum
X Anethum graveolens – dill, Indian dill
Angelica
N Angelica atropurpurea – purplestem angelica, dark-purple alexanders, wild masterwort, great angelica
? Angelica lucida – seabeach angelica, shiny angelica
X Angelica sylvestris
? Angelica venenosa – hairy angelica
Anoda
X Anoda cristata – crested anoda
Antennaria
N Antennaria howellii subsp. canadensis – Canada pussytoes
N Antennaria howellii subsp. howellii – Howell's pussytoes
N Antennaria howellii subsp. neodioica – northern pussytoes, common pussytoes
N Antennaria howellii subsp. petaloidea – small pussytoes
N Antennaria microphylla – littleleaf pussytoes
N Antennaria neglecta – field pussytoes
N Antennaria oxyphylla
N Antennaria parlinii subsp. fallax – largeleaf pussytoes, deceitful pussytoes
N Antennaria parlinii subsp. parlinii – Parlin's pussytoes, smooth pussytoes, plainleaf pussytoes
N Antennaria parvifolia – small-leaf pussytoes, Rocky Mountain cudweed, Nuttall's pussytoes
N Antennaria pulcherrima – showy pussytoes, handsome pussytoes
N Antennaria rosea – rosy pussytoes, pink everlasting
N Antennaria subviscosa
Anthemis
X Anthemis arvensis – corn chamomile, field chamomile
X Anthemis cotula – mayweed, stinking chamomile, fœtid chamomile, dog fennel, stinking mayweed
X Anthemis tinctoria – golden chamomile
Anthoxanthum
X Anthoxanthum odoratum – sweet vernalgrass, sweetgrass
Anthriscus
X Anthriscus cerefolium – common chervil
X Anthriscus sylvestris – wild chervil, woodland chervil, cow parsley, beak-chervil
Anthyllis
X Anthyllis vulneraria – kidney vetch, lady's fingers
Antirrhinum
X Antirrhinum majus – common snapdragon
X Antirrhinum orontium – lesser snapdragon
Ap
Apera
X Apera interrupta – dense silky bentgrass, interrupted bentgrass, interrupted windgrass
X Apera spica-venti – silky bentgrass
Apios
N Apios americana – American groundnut, Indian potato, wild bean, potato-bean
Aplectrum
N Aplectrum hyemale – puttyroot
Apocynum
N Apocynum androsaemifolium – spreading dogbane
N Apocynum cannabinum – Indian hemp, clasping-leaf dogbane, prairie dogbane, velvet dogbane, amyroot
N Apocynum sibiricum – clasping-leaved dogbane
N Apocynum × floribundum (A. androsaemifolium × A. cannabinum) – intermediate dogbane, bitter dogbane
Aq
Aquilegia
N Aquilegia brevistyla – small-flowered columbine
N Aquilegia canadensis – Canadian columbine, red columbine
X Aquilegia vulgaris – European columbine, garden columbine, culverwort, capon's feather
Ar
Arabidopsis
X Arabidopsis thaliana – mouse-ear cress, wall-cress
Arabis
N Arabis alpina subsp. alpina – alpine rockcress
X Arabis alpina subsp. caucasica – wall rockcress, grey rockcress
N Arabis arenicola var. arenicola – arctic rockcress
N Arabis arenicola var. pubescens – sand rockcress
N Arabis canadensis – sicklepod
N Arabis divaricarpa – limestone rockcress
N Arabis drummondii – Drummond rockcress
N Arabis glabra – tower-mustard
N Arabis hirsuta var. adpressipilis – hairy rockcress, creamflower rockcress
N Arabis hirsuta var. pycnocarpa – creamflower rockcress
N Arabis holboelli var. retrofracta – Holboell's rockcress
N Arabis holboelli var. secunda – bristly-leaved rockcress
? Arabis kamchatica – lyreleaf rockcress (species status disputed)
N Arabis laevigata – smooth rockcress
N Arabis lyrata – lyreleaf rockcress
N Arabis shortii – Short's rockcress
Aralia
X Aralia elata – Japanese Angelica-tree, Chinese Angelica-tree
N Aralia hispida – bristly spikenard, bristly sarsaparilla, dwarf elder
N Aralia nudicaulis – wild sarsaparilla, small spikenard
N Aralia racemosa – American spikenard, Indian-root, life-of-man, petty morel
X Aralia spinosa – Hercules' club, Devil's walkingstick, prickly ash, Angelica tree, toothache tree
Arceuthobium
N Arceuthobium americanum – pine mistletoe, American mistletoe, lodgepole pine dwarf mistletoe
N Arceuthobium pusillum – dwarf mistletoe, eastern dwarf mistletoe
Arctagrostis
N Arctagrostis latifolia – polargrass
Arctium
X Arctium lappa – great burdock
X Arctium minus subsp. minus – common burdock
X Arctium minus subsp. nemorosum – lesser burdock
X Arctium pubens – wood burdock
X Arctium tomentosum – woolly burdock, tomentose burdock
X Arctium × nothum (A. lappa × A. minus) – hybrid burdock
Arctophila
N Arctophila fulva – pendant grass
Arctostaphylos
N Arctostaphylos alpina – alpine bearberry
N Arctostaphylos rubra – red manzanita
N Arctostaphylos uva-ursi – bearberry, kinnikinnick, mealberry
Arenaria
N Arenaria humifusa – creeping sandwort, low sandwort, spreading sandwort
X Arenaria serpyllifolia – thymeleaf sandwort
Arethusa
N Arethusa bulbosa – dragon's mouth, swamp pink
Argemone
X Argemone mexicana – Mexican prickly-poppy
Arisaema
N Arisaema dracontium – green dragon Special Concern
N Arisaema triphyllum – Jack-in-the-pulpit
Aristida
N Aristida basiramea – forktip threeawn Endangered
N Aristida dichotoma – Shinner's threeawn
N Aristida longespica var. geniculata – red threeawn
N Aristida longespica var. longespica – slimspike threeawn
X Aristida oligantha – prairie three-awn grass
N Aristida purpurascens – arrow feather threeawn
Aristolochia
X Aristolochia clematitis – birthwort
X Aristolochia macrophylla – pipevine
Armeria
N Armeria maritima – sea thrift, Labrador sea thrift, foxflower
Armoracia
X Armoracia rusticana – horseradish, red cole
Arnica
N Arnica angustifolia – narrowleaf arnica, arctic arnica, arctic leopardbane
N Arnica chamissonis – meadow arnica, Chamisso's arnica, leafy arnica, leafy leopardbane
N Arnica cordifolia – heartleaf arnica, heartleaf leopardbane
N Arnica lonchophylla – northern arnica, longleaf arnica, white-plumed arnica, spearleaf arnica
Arnoglossum
N Arnoglossum platagineum – tuberous Indian-plantain Special Concern
Aronia
N Aronia melanocarpa – black chokeberry
Arrhenatherum
X Arrhenatherum elatius – tall oatgrass, French rye, tuber oatgrass, bulbous oatgrass, false oat grass
Artemisia
X Artemisia abrotanum – southern wormwood, southernwood, lad's love, oldman
X Artemisia absinthium – common wormwood, absinthe, absinthe wormwood, European wormwood
X Artemisia annua – sweet sagewort, annual wormwood, sweet Annie, sweet wormwood, annual mugwort
X Artemisia biennis – biennial wormwood
N Artemisia campestris subsp. borealis – boreal wormwood, Canada wormwood
N Artemisia campestris subsp. caudata – tall wormwood, beach wormwood, wild wormwood, threadleaf sagewort, sagewort wormwood
N Artemisia dracunculus – wild tarragon, dragon wormwood, dragon sagewort, false tarragon, French tarragon, Russian tarragon
N Artemisia frigida – fringed sagebrush, prairie sagebrush, fringed sagewort, prairie sagewort, wormwood sage, pasture sage, arctic sagebrush
N Artemisia ludoviciana – white sage, silver wormwood, prairie sage, western mugwort, darkleaf mugwort, cudweed sagewort, pasture sage, Louisiana wormwood, Louisiana sage, silver king artemisia, white wormwood, white sagebrush
X Artemisia pontica – Roman wormwood, petite wormwood, green ginger
X Artemisia stelleriana – hoary sagebrush, dusty miller, beach wormwood, old woman
N Artemisia tilesii – Tilesius' wormwood, mountain sagewort, oldwoman
X Artemisia vulgaris – common mugwort, common wormwood
Aruncus
X Aruncus dioicus – common goat's-beard
As
Asarum
N Asarum canadense – Canada wild ginger
Asclepias
N Asclepias exaltata – poke milkweed, tall milkweed, four-leaved milkweed
N Asclepias hirtella – tall green milkweed
N Asclepias incarnata – swamp milkweed
N Asclepias ovalifolia – oval-leaf milkweed, dwarf milkweed
N Asclepias purpurascens – purple milkweed
N Asclepias quadrifolia – four-leaved milkweed
N Asclepias sullivantii – Sullivant's milkweed
N Asclepias syriaca – common milkweed, silkweed, silky swallow-wort
N Asclepias tuberosa – butterfly weed, orange milkweed, pleurisy root, chigger flower
? Asclepias variegata – white milkweed
N Asclepias verticillata – whorled milkweed
N Asclepias viridiflora – green milkweed, green comet milkweed, short green milkweed
Asimina
N Asimina triloba – common pawpaw
Asparagus
X Asparagus officinalis – garden asparagus, asparagus-fern
Asperugo
X Asperugo procumbens – German madwort, catchweed
Asperula
X Asperula arvensis – blue woodruff
Asplenium
N Asplenium platyneuron – ebony spleenwort
N Asplenium rhizophyllum – walking fern
N Asplenium ruta-muraria – wall-rue
N Asplenium scolopendrium var. americanum – American Hart's-tongue fern Special Concern
N Asplenium trichomanes – maidenhair spleenwort
N Asplenium viride – green spleenwort
Aster
N Aster alpinus – alpine aster
Astragalus
N Astragalus adsurgens – ascending milkvetch, rattle milkvetch, standing milkvetch
N Astragalus agrestis – field milkvetch, mile-vetch, cock's-head
N Astragalus alpinus – alpine milkvetch
N Astragalus americanus – American milkvetch
N Astragalus australis – Indian milkvetch
N Astragalus canadensis – Canada milkvetch, Carolina milkvetch
X Astragalus cicer – chickpea milkvetch
N Astragalus eucosmus – elegant milkvetch, pretty milkvetch
X Astragalus glycophyllos – wild liquorice
N Astragalus neglectus – Cooper's milkvetch
N Astragalus tenellus – pulse milkvetch, loose-flower milkvetch
At
Athyrium
N Athyrium filix-femina var. angustum – northern lady fern
N Athyrium filix-femina var. cyclosorum – northwestern lady fern
Atriplex
N Atriplex dioica – thickleaf orache, saline saltbush
N Atriplex glabriuscula – smooth orache, Scotland orache, glabrous orache, northeastern saltbush
X Atriplex heterosperma – two-scale orache
X Atriplex hortensis – garden orache
X Atriplex oblongifolia – oblong-leaf orache
N Atriplex patula – spear orache, spreading orache, spearscale, halberdleaf orache, common orache
N Atriplex prostrata – thinleaf orache, triangle orache, fat-hen
X Atriplex rosea – tumbling orache
Au
Aureolaria
N Aureolaria flava – yellow false-foxglove
N Aureolaria pedicularia – fernleaf yellow false-foxglove
N Aureolaria virginica – downy false-foxglove
Aurinia
X Aurinia saxatilis – basket-of-gold, gold dust, gold alyssum
Av
Avena
X Avena fatua – wild oats
X Avena sativa – oats, cultivated oats
X Avena sterilis – animated oats
Ax
Axyris
X Axyris amaranthoides – Russian pigweed, upright axyris
Az
Azolla
N Azolla caroliniana – mosquito fern
References
See: Flora of Canada#References
Plants by genus
Canada,genus | List of Canadian plants by genus | Biology | 6,107 |
25,725,947 | https://en.wikipedia.org/wiki/Network-Integrated%20Multimedia%20Middleware | The Network-Integrated Multimedia Middleware (NMM) is a flow graph based multimedia framework. NMM allows creating distributed multimedia applications: local and remote multimedia devices or software components can be controlled transparently and integrated into a common multimedia processing flow graph. NMM is implemented in C++, a programming language, and NMM-IDL, an interface description language (IDL). NMM is a set of cross-platform libraries and applications for the operating systems Linux, OS X, Windows, and others. A software development kit (SDK) is also provided.
NMM is released under dual-licensing. The Linux, OS X and PS3 versions are distributed free as open-source software under the terms and conditions of the GNU General Public License (GPL). The Windows version is distributed free as binary version under the terms and conditions of the NMM Non-Commercial License (NMM-NCL). All NMM versions (i.e., for all supported operating systems) are also distributed under a commercial license with full warranty, which allows developing closed-source proprietary software atop NMM.
See also
Java Media Framework
DirectShow
QuickTime
Helix DNA
MPlayer
VLC media player (VLC)
Video wall
Sources
Linux gains open source multimedia middleware
KDE to gain cutting-edge multimedia technology
Multimedia barriers drop at CeBIT in March
A Survey of Software Infrastructures and Frameworks for Ubiquitous Computing
External links
NMM homepage
Computer networking
Computer libraries | Network-Integrated Multimedia Middleware | Technology,Engineering | 301 |
53,861,755 | https://en.wikipedia.org/wiki/USAFacts | USAFacts is a not-for-profit organization and website that provides data and reports on the United States population, its government's finances, and government's impact on society. It was launched in 2017.
History and background
USAFacts was founded by former Microsoft CEO and owner of the Los Angeles Clippers, Steve Ballmer. Ballmer invested his own money in the project. USAFacts was launched on April 18, 2017 Tax Day, with the goal of making government data about tax revenues, expenditures, and outcomes more accessible and understandable. USAFacts's platform is designed to provide information to the public about government spending and impact at all levels, from federal to local. It includes information about border apprehensions, climate, immigration, active shooters, medicare, education, military spending and opioids. It also helps entrepreneurs to figure out the best location to launch or invest in businesses.
At launch, the website gathered data from over 70 government agencies and pulls data from more than 130 US government statistical databases and reports. Only official government data is included in the site.
In September 2018, USAFacts launched a new Voter Center. This compares government data with the positions members of Congress state publicly and shares information about education, healthcare, tariffs, jobs, immigration, economy, guns, etc. Partners of the Vote Center are Countable, BallotReady and TurboVote.
In November 2018 USAFacts partnered with GeekWire, to produce the podcast Numbers Geek.
In October 2019, USAFacts linked up with U.S. News & World Report. This provided an outlet to share their data in visual form and in the context of the relevant daily matters to and at the same time increasing U.S. News' 2020 election coverage.
In November 2019, USAFacts in cooperation with AP-Norc, conducted a poll which showed that more than 50% of Americans glean their government-related news from social media, while only 11% would trust its correctness and 64% saw it as untrustworthy information.
During the COVID-19 pandemic, USAFacts launched its USAFacts COVID-19 impact and Recovery Hub. It uses information of government sources, the Bureau of Economic Analysis and the Department of Labor. On March 20, 2020, USAFacts announced its Coronavirus Hub and Map which gives a frequently updated metrics on the daily spread and effect of COVID-19 throughout America.
In 2020, USAFacts partnered with the global nonprofit Earth Day Network.
President Poppy MacDonald testified in front of the United States House Select Committee on the Modernization of Congress in an October 2021 hearing called Strengthening the Lawmaking Process: How Data Can Inform and Improve Policy. She urged the government for datasets that are timely, contextual and relevant to Americans, and talked about the need for more cross-agency and cross-government collaboration.
Awards and recognition
In May 2020, USAFacts won the 2020 Webby Award for Government & Civil Innovation in the category Web.
In August 2021, Fast Company named USAFacts 14th on its third-annual Best Workplaces for Innovators list.
See also
Analytics.usa.gov
Bureau of Justice Statistics
Bureau of Labor Statistics
Data.gov
Data USA
E-government
Open data
United States Census Bureau
USA.gov
References
External links
"CEO Conversation with Steve Ballmer and Patrick Steel" by Politico (2018)
Demography
Organizations established in 2017
American political websites
Internet properties established in 2012
Fact-checking websites | USAFacts | Environmental_science | 708 |
7,806,713 | https://en.wikipedia.org/wiki/Warburg%20hypothesis | The Warburg hypothesis (), sometimes known as the Warburg theory of cancer, postulates that the driver of carcinogenesis (cancer formation) is insufficient cellular respiration caused by insult (damage) to mitochondria. The Warburg effect, on the other hand, describes the observation that cancer cells, and many cells grown in vitro, exhibit glucose fermentation even when enough oxygen is present to properly respire. In other words, instead of fully respiring in the presence of adequate oxygen, cancer cells ferment. The Warburg hypothesis is that the Warburg effect is the root cause of cancer.
Hypothesis
The hypothesis was postulated by the Nobel laureate Otto Heinrich Warburg in 1924. He hypothesized that cancer, malignant growth, and tumor growth are caused by the fact that tumor cells mainly generate energy (as e.g., adenosine triphosphate / ATP) by non-oxidative breakdown of glucose (a process called glycolysis). This is in contrast to healthy cells which mainly generate energy from oxidative breakdown of pyruvate. Pyruvate is an end-product of glycolysis, and is oxidized within the mitochondria. Hence, according to Warburg, carcinogenesis stems from the lowering of mitochondrial respiration. Warburg regarded the fundamental difference between normal and cancerous cells to be the ratio of glycolysis to respiration; this observation is also known as the Warburg effect.
In the somatic mutation theory of cancer, malignant proliferation is caused by mutations and altered gene expression, in a process called malignant transformation, resulting in an uncontrolled growth of cells. The metabolic difference observed by Warburg adapts cancer cells to the hypoxic (oxygen-deficient) conditions inside solid tumors, and results largely from the same mutations in oncogenes and tumor suppressor genes that cause the other abnormal characteristics of cancer cells. Therefore, the metabolic change observed by Warburg is not so much the cause of cancer, as he claimed, but rather, it is one of the characteristic effects of cancer-causing mutations.
Warburg articulated his hypothesis in a paper entitled The Prime Cause and Prevention of Cancer which he presented in lecture at the meeting of the Nobel-Laureates on June 30, 1966 at Lindau, Lake Constance, Germany. In this speech, Warburg presented additional evidence supporting his theory that the elevated anaerobiosis seen in cancer cells was a consequence of damaged or insufficient respiration. Put in his own words, "the prime cause of cancer is the replacement of the respiration of oxygen in normal body cells by a fermentation of sugar."
The body often kills damaged cells by apoptosis, a mechanism of self-destruction that involves mitochondria, but this mechanism fails in cancer cells where the mitochondria are shut down. The reactivation of mitochondria in cancer cells restarts their apoptosis program.
See also
Carcinogen
Carcinogenesis
2-Deoxy-D-glucose
Pyruvic acid
Cellular respiration
Inverse Warburg effect
References
Further reading
Cancer
Oncology
Mitochondria
Molecular biology | Warburg hypothesis | Chemistry,Biology | 657 |
3,213,090 | https://en.wikipedia.org/wiki/Circumambulation | Circumambulation (from Latin circum around and ambulātus to walk) is the act of moving around a sacred object or idol.
Circumambulation of temples or deity images is an integral part of Hindu and Buddhist devotional practice (known in Sanskrit as pradakśiṇā). It is also present in other religions, including Christianity, Judaism, and Islam.
Indian religions
In many Hindu temples, the temple structure reflects the symbolism of the Hindu association of the spiritual transition from daily life to spiritual perfection as a journey through stages. Passageways for circumambulation are present through which worshipers move in a clockwise direction, starting at the sanctuary doorway and moving inward toward the inner sanctum where the deity is enshrined. This is a translation of the spiritual concept of transition through levels in life into bodily movements by the worshipers as they move inwardly through ambulatory halls to the most sacred centre of spiritual energy of the deity. It is done in a clockwise direction and in an odd rather than even number of times. Circumambulatory walking around the shrine, by keeping time, is a common form of Hindu prayer. The ambulatory pathway made of stone around the shrine is called the Pradakshina path.
Buddhism
Also called pradakṣina or caṅkramaṇa in Sanskrit.
Zen Buddhism
In Zen Buddhism, jundō (巡堂) can mean any ritual circuit or circumambulation. At Tassajara each morning, the officiating priest (導師 dōshi) visits four different altars on their way to the zendō, to make bows and offerings of incense. This jundō begins with the first rolldown of the han, and ends as the dōshi enters the zendō with the third rolldown. After offering incense and bowing at the altar, the dōshi walks around the zendō behind the meditators, in what is called the kentan (検単), inspection of the sitting platform. As the dōshi passes, each resident raises their hands in gasshō (合掌) without bowing. This joins the dōshi and sitters in mutual acknowledgement.
Sikhism
In Lavan Pheras, which is performed during wedding ceremonies, the four rounds of symbolize a sacrosanct bond in the form of circumambulation of a purifying object, in this case the holy book, Sri Guru Granth Sahib.
Abrahamic religions
Christianity
In the Catholic Church, a priest sometimes circumambulates an altar while incensing it with a thurible. Also, at some Catholic shrines, it is a tradition to circle the cult object of the place, usually relics of a saint or an image of Jesus or the Virgin Mary. Often this is performed three times, as a reference to the Trinity. In the Tridentine Rite the elements of Bread and Wine are also incensed before the Consecration by encircling them, twice counterclockwise, once clockwise. This incensing was accompanied with Latin prayer.
In Romania, there is an Easter custom to process around the church three times by singing priests leading the people, just before finishing Easter Liturgy. It symbolizes the funerary procession of the burial of Jesus Christ.
Circumambulation is common in many Eastern Orthodox and Oriental Orthodox services. In the Coptic tradition, during the liturgy, the priest circles the altar while an acolyte (altar boy) holds a cross high on the opposite side.
This is also a common practice in Lutheran, Roman Catholic, Anglican and Methodist churches during Lent when Stations of the Cross services are celebrated. The priest along with altar servers process around the interior of the church visiting each of the 14 stations.
On Palm Sunday in the churches of many Christian denominations, members of the congregation, oftentimes children, are given palms that they carry as they walk in a procession around the inside of the church. In the Church of Pakistan, a united Protestant Church, the faithful on Palm Sunday carry palm branches into the church as they sing Psalm 24.
Islam
Tawaf (طواف) is one of the Islamic rituals of pilgrimage. During the Hajj and Umrah, Muslims are to circumambulate the Kaaba (most sacred site in Islam) seven times, in a counter-clockwise direction. The circling is believed to demonstrate the unity of the believers in the worship of God, as they move in harmony together around the Kaaba, while supplicating to Allah.
Judaism
Judaism uses circumambulation in the Hakafot ritual during the Festival of Sukkot culminating in seven Hakafot on Hoshanah Rabbah, the end of the Festival. They are also performed during Hakafot on Simchat Torah, where Jews often dance circling the Torah Scrolls. Traditionally, Jewish brides circumambulate their grooms during the wedding ceremony under the chuppah and much Jewish dancing at weddings and Bar Mitzvahs is done by moving in a circle.
According to the Mishnah in Tractate Middot 2:2, when a person ascended to the Temple Mount in Jerusalem on the Three Pilgrimage Festivals in the time of the Temple's existence, they would circumambulate counter-clockwise. Someone who had something bad happen to them would circumambulate clockwise so that when someone saw them going in this unusual direction the person could tell them what was wrong (i.e., they were a mourner or were excommunicated) and the person encountering them would pray for them in the name of "the One who dwells in this House."
Baháʼí Faith
Followers of the Baháʼí Faith perform circumambulation of both the Shrines of the Báb and Bahá'u'lláh during their lesser pilgrimage to Haifa and Bahjí, in Palestine. While circumambulating, observance of these Manifestations of God is done in complete silence and also performed on holy days such as the birth and ascension of Bahá'u'lláh as well as the birth and martyrdom of the Báb.
Bön
The Bönpo in the Tibet traditionally circumambulate (generally) in a counter-clockwise direction, that is a direction that runs counter to the apparent movement of the Sun.
Freemasonry
Candidates for the three principle degrees of Freemasonry circumambulate the altar in the lodge room. It is done in a clock-wise fashion. The number of times which candidates ambulate around the altar depends on which degree is being presented.
See also
Sunwise (clockwise)
Widdershins (counter-clockwise)
Circle dance
Kora (pilgrimage)
Parikrama
Svastika
Sauvastika
Stupa
References
Ritual
Walking
pl:Pradakszina
ru:Парикрама | Circumambulation | Biology | 1,407 |
32,132,039 | https://en.wikipedia.org/wiki/Ring%20saw | A ring saw is a form of bandsaw where the band is rigid, rather than flexible. This requires the band to be circular, rather than the bandsaw's usual oblong of straight runs between two (or three) guide wheels.
Ringsaw blades are abrasive rather than toothed. The brittleness of this abrasive coating, and the need to avoid flexure, is why they are made as rings rather than oval bands. As the ring is a circle of constant radius, the blade is not flexed or bent in operation. The blades themselves are not usually rigid and may be bent slightly in fitting, but are not designed to be flexed as they rotate.
Abrasive sawblades, as used in ringsaws, are mostly used in the working of art glass. They use a steel band or ring, coated with a diamond abrasive, attached by nickel electroplating. Abrasive saws are used for a range of hard, brittle materials, such as in mineralogy. Ceramic tiles may also be sawn.
The main form of ring saw uses a ring or wire that is like a flat disk. The non-cutting side of the blade is behind the cutting edge, so limits the depth of the cuts that may be made. Wire-saws are coated with an abrasive on all sides and so may cut in any direction. With the ring behind the cutting edge, cuts in the main direction will treat the blade (in mechanical terms) as an arch, which is stiffer than a sideways force on a cylindrical blade. This geometry also gives a vertical cut in thick materials, although the cut must be kept straight and unlike a bandsaw, curves cannot be sawn if the material is thick. They may be used for mineralogy and slabbing.
Many makers of ringsaws offer a similar blade as a bandsaw too. The ringsaw blade in comparison may be made rigid, thus stronger and less flexible under cutting loads, giving a more accurate cut. Some make a particular feature of the ring saw's ability to cut forwards, backwards and sideways. As the bandsaw blade must be flexible enough to pass around the wheels, its blades are limited to cutting on the forward edge. The oblong bandsaw has a blade that is supported on two large wheels. The interval between the two wheels is supported by blade guides immediately behind the cutting zone. Ring saws do not have the same straight run of blade, nor the opportunity to support much of the blade as with the wheels of a bandsaw. A ring saw is thus a somewhat fragile machine and excess pressure on a thin blade is likely to damage it.
Abrasive saws are often water-cooled and most ring saws are designed to enable this, with water pumps or drip feeds, and catch trays.
Concrete ring saws
Concrete and masonry-cutting 'ring' saws are a form of disk cutter and are unrelated to bandsaws. They do however also use a diamond abrasive.
References
Glass art
Saws
Cutting machines | Ring saw | Physics,Technology | 620 |
41,636,873 | https://en.wikipedia.org/wiki/Lepiota%20saponella | Lepiota saponella is a species of agaric fungus in the family Agaricaceae. Found in France, it was described as new to science in 1994.
The fruit bodies (mushrooms) closely resemble those of the widespread species Lepiota cristata. L. saponella can be distinguished by its soapy smell, dingy buff-coloured gills, and smaller scales on the cap surface. Microscopically, its spores are more triangular than those of L. cristata.
See also
List of Lepiota species
References
External links
saponella
Fungi described in 1994
Fungi of Europe
Fungus species | Lepiota saponella | Biology | 127 |
23,997,153 | https://en.wikipedia.org/wiki/Informatics | Informatics (a combination of the words "information" and "automatic") is the study of computational systems. According to the ACM Europe Council and Informatics Europe, informatics is synonymous with computer science and computing as a profession, in which the central notion is transformation of information. In some cases, the term "informatics" may also be used with different meanings, e.g. in the context of social computing, or in context of library science.
Different meanings
In some countries, depending on local interpretations and contexts, the term "informatics" is used synonymously to mean information systems, information science, information theory, information engineering, information technology, information processing, or other theoretical or practical fields. In Germany, the term informatics closely corresponds to modern computer science. Accordingly, universities in continental Europe usually translate "informatics" as computer science, or sometimes information and computer science, although technical universities may translate it as computer science & engineering.
In the United States, however, the term informatics is mostly used in context of data science, library science or its applications in healthcare (health informatics), where it first appeared in the US.
The University of Washington uses this term to refer to social computing. In some countries, this term is associated with natural computation and neural computation.
The Government of Canada uses the term to refer to operational units offering network and computer services to the various departments.
Etymology
In 1956, the German informatician Karl Steinbuch and engineer Helmut Gröttrup coined the word Informatik when they developed the Informatik-Anlage for the Quelle mail-order management, one of the earliest commercial applications of data processing. In April 1957, Steinbuch published a paper called Informatik: Automatische Informationsverarbeitung ("Informatics: Automatic Information Processing"). The morphology—informat-ion + -ics—uses "the accepted form for names of sciences, as conics, mathematics, linguistics, optics, or matters of practice, as economics, politics, tactics", and so, linguistically, the meaning extends easily to encompass both the science of information and the practice of information processing. The German word Informatik is usually translated to English as computer science by universities or computer science & engineering by technical universities (German equivalents for institutes of technology). Depending on the context, informatics is also translated into computing, scientific computing or information and computer technology. The French term informatique was coined in 1962 by Philippe Dreyfus. In the same month was also proposed independently by Walter F. Bauer (1924–2015) and associates who co-founded software company Informatics Inc. The term for the new discipline quickly spread throughout Europe, but it did not catch on in the United States. Over the years, many different definitions of informatics have been developed, most of them claim that the essence of informatics is one of these concepts: information processing, algorithms, computation, information, algorithmic processes, computational processes or computational systems.
The earliest uses of the term informatics in the United States was during the 1950s with the beginning of computer use in healthcare. Early practitioners interested in the field soon learned that there were no formal education programs, and none emerged until the late 1960s. They introduced the term informatics only in the context of archival science, which is only a small part of informatics. Professional development, therefore, played a significant role in the development of health informatics. According to Imhoff et al., 2001, healthcare informatics is not only the application of computer technology to problems in healthcare, but covers all aspects of generation, handling, communication, storage, retrieval, management, analysis, discovery, and synthesis of data information and knowledge in the entire scope of healthcare. Furthermore, they stated that the primary goal of health informatics can be distinguished as follows: To provide solutions for problems related to data, information, and knowledge processing. To study general principles of processing data information and knowledge in medicine and healthcare. The term health informatics quickly spread throughout the United States in various forms such as nursing informatics, public health informatics or medical informatics. Analogous terms were later introduced for use of computers in various fields, such as business informatics, forest informatics, legal informatics etc. These fields still mainly use term informatics in context of library science.
Informatics as information processing science
In the early 1980s, K.A Nicholas published "Informatics: Ready for the Information Society" proposing a definition of Informatics as "the study and the practice of skills related to information, its collection, storage, retrieval, analysis and publication. In short; - Information Handling." It had been developed in the South Australian Education System at a grass roots level. <K.A Nicholas published "Informatics: Ready for the Information Society" 1983 - National Library of Australia>
In the early 1990s, K.K. Kolin proposed an interpretation of informatics as a fundamental science that studies information processes in nature, society, and technical systems.
A broad interpretation of informatics, as "the study of the structure, algorithms, behaviour, and interactions of natural and artificial computational systems," was introduced by the University of Edinburgh in 1994. This has led to the merger of the institutes of computer science, artificial intelligence and cognitive science into a single School of Informatics in 2002.
More than a dozen nearby universities joined Scottish Informatics and Computer Science Alliance. Some non-European universities have also adopted this definition (e.g. Kyoto University School of Informatics).
In 2003, Yingxu Wang popularized term cognitive informatics, described as follows:
Informatics as a fundamental science of information in natural and artificial systems was proposed again in Russia in 2006.
In 2007, the influential book Decoding the Universe was published.
Former president of Association for Computing Machinery, Peter Denning wrote in 2007:
The 2008 Research Assessment Exercise, of the UK Funding Councils, includes a new, Computer Science and Informatics, unit of assessment (UoA), whose scope is described as follows:
The UoA includes the study of methods for acquiring, storing, processing, communicating and reasoning about information, and the role of interactivity in natural and artificial systems, through the implementation, organisation and use of computer hardware, software and other resources. The subjects are characterised by the rigorous application of analysis, experimentation and design.
In 2008, the construction of the Informatics Forum was completed. In 2018, the MIT Schwarzman College of Computing was established. Its construction is planned to be completed in 2021.
Informatics as information science
In the fields of geoinformatics or irrigation informatics, the term -informatics usually mean information science, in context related to library science. This was the first meaning of informatics introduced in Russia in 1966 by A.I. Mikhailov, R.S. Gilyarevskii, and A.I. Chernyi, which referred to a scientific discipline that studies the structure and properties of scientific information. In this context, the term was also used by the International Neuroinformatics Coordinating Facility. Some scientists use this term, however, to refer to the science of information processing, not data management.
In the English-speaking world, the term informatics was first widely used in the compound medical informatics, taken to include "the cognitive, information processing, and communication tasks of medical practice, education, and research, including information science and the technology to support these tasks". Many such compounds are now in use; they can be viewed as different areas of "applied informatics".
Informatics as computer science
In some countries such as Germany, Russia, France, and Italy, the term informatics in many contexts (but not always) can translate directly to computer science.
Related topics
Computer scientists study computational processes and systems. Computing Research Repository (CoRR) classification distinguishes the following main topics in computer science (alphabetic order):
artificial intelligence
computation and language
computational complexity
computational engineering, finance, and science
computational geometry
computational game theory
computer vision and pattern recognition
computers and society
cryptography and security
data structures and algorithms
databases and digital libraries
distributed, parallel and cluster computing
emerging technologies
formal languages and automata theory
general literature
graphics
hardware architecture
human-computer Interaction
information retrieval
information theory
logic in computer science
machine learning
mathematical software
multiagent systems
multimedia
networking and internet architecture
neural computing and evolutionary computing
numerical analysis
operating systems
other computer science
performance
programming languages
robotics
social and information networks
software engineering
sound
symbolic computation
systems and control
Journals and conferences
Information and Computation Acta Informatica Information Processing Letters Neural Information Processing Systems Journal of Automata, Languages and Combinatorics International Journal of Cognitive Informatics and Natural Intelligence Conference on Computer Vision and Pattern Recognition)
Symposium on Theory of Computing European Conference on Computer Vision Brain Informatics International Conference on Computer Vision International Conference on Machine Learning Algorithmica Symposium on Foundations of Computer Science) European Symposium on Algorithms Fundamenta Informaticae Symposium on Discrete Algorithms Journal of Logic and Computation Bioinformatics
Neural Computing and Applications Autonomous Agents and Multi-Agent Systems
International Symposium on Fundamentals of Computation Theory International Colloquium on Automata, Languages and Programming Journal of Scientific Computing Annual IEEE Symposium on Foundations of Computer Science Annual Symposium on Computational Geometry Simulation & Gaming Journal of Machine Learning Research Journal of Artificial Intelligence Research ACM Transactions on Graphics IEEE Transactions on Visualization and Computer Graphics IEEE Transactions on Computers IEEE/ACM International Symposium on Microarchitecture ACM Symposium on Computer and Communications Security Symposium on Parallelism in Algorithms and Architectures Symposium on Foundations of Computer Science''
Community
Related organisations
Informatics Europe
Association for Computing Machinery
IEEE Computer Society
Scottish Informatics and Computer Science Alliance
Computing Research Association
Association for the Advancement of Artificial Intelligence
American Society for Information Science and Technology
International Federation for Information Processing
Association for Logic, Language and Information
Gesellschaft für Informatik
Association for Women in Computing
Computer Science Teachers Association
Computability in Europe
European Association for Theoretical Computer Science
Raspberry Pi Foundation
Academic schools and departments
Information School at University of Washington
College of Emergency Preparedness, Homeland Security and Cybersecurity at University at Albany, SUNY
Department of Informatics at University of California, Irvine
College of Literature, Science, and the Arts at University of Michigan
School of Information at The University of Texas at Austin
Manning College of Information & Computer Sciences at University of Massachusetts Amherst
Texas Women's University
College of Literature, Science, and the Arts at University of Michigan
Department of Informatics at Indiana University Bloomington
School of Informatics and Computing at Indiana University–Purdue University Indianapolis
School of Information at San Jose State University
School of Computing and Informatics at University of Louisiana at Lafayette
Department of Computer Science at The University of Iowa
Ira A. Fulton Schools of Engineering at Arizona State University
School of Informatics, Computing, and Cyber Systems at Northern Arizona University
School of Engineering and Computer Science at Baylor University
College of Information Sciences and Technology at Pennsylvania State University
College of Engineering and Computing at University of South Carolina
Doctoral School of Informatics at University of Debrecen
School of Information Sciences at University of Illinois Urbana-Champaign
University of Sussex
Institute for Data Science & Informatics at University of Missouri
Norwegian University of Science and Technology
Department of Informatics at University of Bergen
School of Informatics at University of Edinburgh
Department of Informatics at Technical University of Munich
Università della Svizzera italiana
List of Information Schools
See also
Artificial intelligence
Behavior informatics
Computational theory of mind
Computer simulation
Data processing
Data engineering
Data analysis
Entscheidungsproblem
Information and computer science
Information engineering
Information science
Information system
Information technology
Information theory
Machine learning
Models of neural computation
Neural computation
Real-time computing
References
Further reading
Cognitive science
Computer science education
Information science
Computational fields of study
Library science
French words and phrases
German words and phrases
Italian words and phrases
Russian words and phrases
Spanish words and phrases | Informatics | Technology | 2,382 |
10,213,695 | https://en.wikipedia.org/wiki/Takifugu%20rubripes | Takifugu rubripes, commonly known as the Japanese puffer, Japanese pufferfish, Tiger puffer, or torafugu (), is a pufferfish in the genus Takifugu. It is distinguished by a very small genome that has been fully sequenced because of its use as a model species and is in widespread use as a reference in genomics.
Taxonomy and etymology
The species is often referred to in the genomics literature as Fugu rubripes. The genus Fugu is a synonym of the currently preferred Takifugu. Takifugu is Japanese for puffer and rubripes comes from the Latin ruber and pēs meaning ruddy foot.
Distribution and habitat
The species is known from the Sea of Japan, East China Sea and Yellow Sea north to southern Sakhalin, at depths of . It is a demersal species. Spawning occurs in estuaries; young fish can tolerate a wide range of salinities and will remain in river mouths and lagoons, maturing for one year before migrating permanently to the open ocean.
Genome
A feature of this species is that it has a very small genome, which is used as a 'reference' for identifying genes and other elements in human and other vertebrate genomes. The genome was published in 2002 by the International Fugu Genome Consortium via whole genome shotgun sequencing. After being initiated in 1989, it was the first vertebrate genome after the human genome to be made publicly available. It remains among the smallest known vertebrate genomes; its number of base pairs is ~6% and the number of previously known protein-coding genes ~13% that of the human genome, although the number of chromosomes (22) is comparable to that of humans (23). This makes it particularly useful for comparative studies. Current estimates show a total of 392,376,244 base pairs, 1,138 known and 18,093 novel protein-coding genes, and 593 RNA genes.
One type of torafugu, 22-seiki fugu (meaning "22nd-century fugu"), has been genetically modified by removing four leptin receptor genes that control appetite. The result has increased appetite and weight gain, growing on average 1.9 times faster than normal torafugu. It is sold commercially as food.
Toxicity
As some other pufferfish, some organs of the Japanese puffer contain tetrodotoxin and are highly toxic. The toxin is highly concentrated in liver and ovaries, slightly present in the intestines and flesh, and absent from skin and testes.
Conservation
The Japanese puffer is classified as Near Threatened by the IUCN. It is one of the most valuable commercial fishes in Japan, and although current catches (101 tonnes / year in 2004, down from a peak of 2,000 tonnes in 1987) are small compared to those of many other commercial species such as sardines and anchovy, they appear to be unsustainable and prevent the recovery of the species from earlier over-exploitation. Gear restrictions (most catches occur by longline fishing) and adjustments of fishery seasons to protect juveniles have been recommended to aid recovery. The species is extensively raised in aquaculture.
References
External links
Fugu Genome Project
Interactive chromosome linkage map
View the fugu genome on Ensembl
rubripes
Fish described in 1850
Animal models
Genomics
Taxa named by Coenraad Jacob Temminck
Taxa named by Hermann Schlegel | Takifugu rubripes | Biology | 717 |
3,678,005 | https://en.wikipedia.org/wiki/Instant%20Messaging%20and%20Presence%20Protocol | Instant Messaging and Presence Protocol (IMPP) was an IETF working group created for the purpose of developing an architecture for simple instant messaging and presence awareness/notification. It was created on and concluded on .
Documents
See also
Presence and Instant Messaging (PRIM)
SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE)
Extensible Messaging and Presence Protocol (XMPP) AKA Jabber
References
External links
– IETF Datatracker
Instant messaging protocols
Working groups | Instant Messaging and Presence Protocol | Technology | 95 |
35,128,195 | https://en.wikipedia.org/wiki/Cunninghamella%20septata | Cunninghamella septata is a species of fungus in the family Cunninghamellaceae. It was described as new to science by mycologist Ru-Yong Zheng in 2001. Colonies of C. septata are low and flat, not greater than 1 mm high. Growth of the fungus is slow at , taking 14 days to reach a diameter of when grown on standard methods agar. The maximum growth temperature is . The specific epithet refers to septa, which are present and common in all parts of the fungus.
References
External links
Fungi described in 2001
Cunninghamellaceae
Fungus species | Cunninghamella septata | Biology | 116 |
1,612,992 | https://en.wikipedia.org/wiki/Scooba%20%28brand%29 | Scooba was a floor-scrubbing robot made by iRobot. It was released in limited numbers in December 2005 for the Christmas season, with full production starting in early 2006. The company introduced a lower-priced version, the Scooba 5800, in the second half of 2006. It introduced a new Scooba 450 at CES 2014 in January 2014.
By 2016, the Scooba line of floor-scrubbers were phased out in favor of the Braava line of floor-mopping robots.
Operation
The Scooba used either a special non-bleach cleaning solution named "Scooba juice" (made by the Clorox Company) formulated to clean the floors while discouraging rust or wheel slippage, or the newer Scooba Natural Enzyme cleaning solution. The robot prepared the floor by vacuuming loose debris, squirted clean solution on the floor, scrubbed the floor, and then sucked up the dirty solution leaving a nearly dry floor behind. The robot was safe to use on sealed hardwood floors and most other hard household surfaces, but could not be used on rugs. Scooba avoided cleaning rugs and stairs, and could clean about on a single tank-load of solution.
Some models of the Scooba included an iRobot Virtual Wall accessory, which projected a beam of infrared light, setting a boundary which the robot would not cross.
The Scooba was the second major commercial product made by iRobot, which popularized vacuum robots with the Roomba. It was available in over 40 countries.
Systems
The Scooba used approximately of cleaning solution per cycle, mixed with of water to fill the cleaning solution tank. The Scooba came with four packets of the new "Natural Enzyme" cleaning solution, enough for about four washes. Additional Clorox cleaning solution comes in five- and nine-packs of bottles, which provided enough solution for about 16 washings per bottle. Polysorbate 20 and tetrapotassium EDTA were the primary ingredients. Some Scooba models could also use white vinegar or plain water in place of the proprietary solution.
Recharge times were typically 3 hours.
Models
The original Scooba
Scooba 5900 was the first Scooba, it could be used with the Scooba Cleaning Solution, or other suitably conductive solutions, but was discontinued in favor of the Scooba 5800 version (basic floor washing model) which could also use plain water in its cleaning tank. iRobot shed several of the 5900's premium features to produce the lower-priced 5800 model. There were no changes to the basic floor cleaning machinery.
The Scooba 5800 could clean about per battery charge.
Scooba 230
Introduced in 2011, the Scooba 230 was a smaller model, less than half the diameter but taller than the previous Scooba models. The reduced diameter allowed the robot to clean more areas in small bathrooms, kitchens, and other tight spaces. In order to reduce the size, the clean water and dirty water tanks were replaced with an internal clean water bladder in a sealed compartment that holds the dirty water, allowing the dirty water storage to expand as the clean water was used up. It worked the same way as the other Scoobas, only there is no scrubbing brushes, but bristles. Only Scooba cleaning solution and water are recommended as vinegar and the original cleaning solution will damage the bladder. The initial vacuuming stage present in other Scooba models was also removed, requiring users to sweep up or vacuum loose debris to start. The Scooba 230 could clean up to in one charge.
The Scooba 230’s. main downfall was that it had to be charged manually and that it did not have screws to hold it together making fixing it near impossible.
Scooba 450
The fourth generation Scooba 450 was introduced at the Consumer Electronics Show 2014. It could mop tile, wood, linoleum, and more. It uses a three-stage cleaning process. First, it sweeps and pre-soaks the floor with cleaning solution, and then it scrubs the floor and squeegees the dirty solution.
Discontinuation
iRobot launched the Braava line of floor mopping robots in 2013, which eventually replaced the Scooba brand by 2016.
References
External links
Scooba homepage
Scooba Product Page
Scooba manual
PC Magazine review
Time gadget of the week
USA Today review
Home appliance brands
Domestic robots
IRobot
2005 robots | Scooba (brand) | Technology | 931 |
25,528,333 | https://en.wikipedia.org/wiki/Transorma | The Transorma was the first large-scale multi-position mail sorting machine, built by the Dutch heavy industrial company, Werkspoor. The name is an acronym for "TRANsport and SORting, Marchand and Andriessen", the last names of the inventors.
Transorma machines had up to five stations where letters were presented one at a time to operators who read the address, selected a routing code that was typed onto the front of the letter, and then sent it off to be automatically sorted into one of up to 300 chutes. Several models were offered; the first U.S. postal station to install a Transorma system used the "5/300" model, which supported 5 sorters and 300 bins. Smaller models, like the "1/150", were similar in concept but were operated by a single sorter and used different mechanism for the sorting.
The Transorma was introduced in the Netherlands in 1927, and the first production version started operations in Rotterdam in 1930. Further sales in the Netherlands followed, but widespread adoption was interrupted by World War II. New installations followed after the war and the machines spread around the world during the 1950s. However, they were used for only a short period of time before computerized systems replaced them in the 1960s.
History
Manual sorting
Traditional manual mail sorting broke the routing task into a hierarchy of sorting stations. Letters were delivered to sorters who examined the address and placed it in one of a number of "pigeon holes". At smaller sorting offices, the pigeon holes could represent individual delivery routes. Runners would collect all the mail from a particular route's pigeon hole from all of the sorting stations in the office and then hand it off to the deliverymen.
At larger sorting stations there were many potential routes, and a single sorter could not be expected to remember them all. For instance, all the out-of-state mail routed to New York state might be sent to a single state-wide sorting station, as stations in other states could not be expected to know how to route to various cities within New York. Sorters at the station would sort the mail by general geographical area, perhaps "Buffalo area" or "Albany". The letters in these pigeon holes would be collected up and sent to other sorting stations, perhaps for the branch office that served a single town, where it would be sorted again to the routes within that city. Mail might have to go through several sorting steps before it reached the level of the deliveryman.
One of the fundamental limits on the number of routes a single sorter could service was the length of their arms. This limited the stack of pigeon holes to a cabinet three to four feet on a side. Making the pigeon holes smaller allowed any one sorter to have more of them within reach, but increased the effort needed to place the letter in the bin, as well as reducing the number of letters that could be sent to a given destination before the pigeon hole filled up. Most stations had about two dozen pigeon holes, which demanded huge numbers of sorters to handle large volumes of mail and routes.
Transorma
Transorma was an attempt to solve the problem of providing more pigeon holes for any one sorter through the use of mechanical switching. Instead of the operator placing the mail directly in a pigeon hole, the machinery would do this for them. This not only greatly increased the number of pigeon holes a sorter could "reach", it also allowed each bin to be much larger, reducing the number of times mail had to be collected out of them.
Sorters read the address and selected a routing code on a keyboard. The machine typed the normally two-letter routing code onto the front of the mail in colored ink, allowing it to be sorted by hand at other offices. The machine then used the same typed route to set up a series of mechanical switches in the mechanism and then moved the mail to the proper bin, often at a long distance from the sorter. In theory, the machine could be expanded to any number of bins, but the majority had either 250 or 300.
The Transorma was first displayed in 1927. The first machine was installed in Rotterdam in 1929 and started full operation in 1930. Another was set up in Haarlem, followed by installations in Utrecht, Breda (a 1/150), 's-Hertogenbosch (Den Bosch) and 's-Gravenhage (The Hague). The original machine in Rotterdam was used until July 1968, and one of these was sent to the Museum voor Communicatie in 1981.
In the U.K. a similar machine had been displayed at the 1924 British Empire Exhibition, but not installed. A decade later, two 5/250 machines were set up in Brighton, officially opening on 7 October 1935. The machines remained in use until 25 May 1968, and were broken up for scrap the next month.
A 5/300 was demonstrated at the 1939 New York World's Fair in New York City, in partnership with Pitney-Bowes who acted as Werkspoor's local sales agent. No sales were made before the war started. Another international sale was made to Rio de Janeiro, which started operation until 1940. In 1942 the Germans moved one of the Dutch Transormas to Steglitz in Berlin and another to Mönchengladbach in the Ruhr. The Mönchengladbach machine was destroyed by bombing in 1943.
Post-war sales
Two were installed in Belgium in 1947, one in Brussels and another in Ghent. Further sales to Brazil were interrupted by the war, but in the post-war period another was set up in São Paulo in 1952, and Belo Horizonte in 1954. Argentina purchased several Transormas following the war, Buenos Aires started their 5/300 in 1948, followed by 5/300's in Rosario and Bahía Blanca in 1949, and another 1/160 in Bahía Blanca in 1955. Venezuela installed a 5/300 in Caracas in 1956.
Transormas were also tested in Linköping and Norrköping in Sweden in 1949 and used through 1950 before the test was abandoned. They felt that the machines placed too much demand on the sorter's memories to be truly effective. Although they were concerned about this problem, the Canadian Post Office installed a 5/300 at their new sorting office in Peterborough, Ontario, in 1955. This machine operated only until 1963, when it was shut down and later sold for scrap in early 1964. Even prior to the Transorma installation, the Canadians had started work on a computerized system that looked up addresses as well as sorted the mail, the Route Reference Computer.
On 10 April 1957 the first U.S. Transorma, a 5/300, started operation at the Blair Station Post Office in Silver Spring, Maryland. At the time it was launched with great fanfare, described at the time "as history-making as the Pony Express, the train, and the plane in speeding up mail handling." However, the U.S. Post Office by this time had seen the Canadian Route Reference Computer prototype and was in the process of launching an effort to build a similar system. The Silver Spring machine was the only Transorma to be installed in the U.S. A plaque is all that remains of this installation, after the buildings were removed in 2003.
Another Transorma was used in Providence (Rhode Island) in early 1960s.
Description
The larger multi-position Transorma machines were 13 foot (4 m) tall, long and about wide, and weighed . They were arranged as a two-story structure with the delivery bins on the bottom and the sorting stations on top. The upper area was ringed by a walkway protected by handrails.
Mail was first sized to remove non-standard packages, and then fed onto a long conveyor belt running from the ground floor up to the sorting stations on the top. The sorting stations would extract letters from the belt and place them at the back of a large queue of letters that for each of the operators. The operators were presented with letters one at a time at the front of the queue, and selected a two-letter routing code from memory.
Once the route was selected, the code was typewritten onto the front of the letter, typically in colored ink printed 90 degrees to the written address. The letter then dropped through the sorting station into a row of spinning wheels that propelled the letter through the bin area. Mechanical shutters, activated by the same keypad entries, opened to allow the letter to drop through into the bins. The bins were much larger than a typical pigeon hole, reducing the number of collections. In full operation, the 5/300 Transorma could sort 15,000 letters per hour. This was about double the rate that the same number of clerks could sort by hand.
The single-user machines were considerably different. These machines were a single floor with the operator sitting at one end. Letters were picked up from the machine and sent to a conveyor running above the sorting bins, then dropped when it was over the right column of bins. A series of shutters behind the bins selected the right one in the stack. Basic workflow was otherwise unchanged.
References
Notes
Bibliography
Allison Marsh, "Former Object of the Month: Transorma Letter Sorting Machine", National Postal Museum (US), July 2006
Jerry McCoy, "Cancelled!", Takoma & Silver Springs Voice
Patents
Jean Joseph Martin Lambert Marchand and Jacobus Cornelus Andriessen, "U.S. Patent 1,774,447, Sorting or Distributing Apparatus", filed 27 October 1925, granted 26 August 1930
Jean Joseph Martin Lambert Marchand and Jacobus Cornelus Andriessen, "U.S. Patent 1,856,165, Mail Distributing Apparatus", filed 30 August 1930, granted 3 May 1932
External links
"Sorting"
"Foreign Transorma", a selection of Transorma marks from around the world
"Transorma Sorting Marks", Charles Livermore's page shows the various two-letter marks that the Canadian Transorma could make
Mail sorting
Postal systems | Transorma | Technology | 2,072 |
1,879,522 | https://en.wikipedia.org/wiki/Dichlorine%20monoxide | Dichlorine monoxide is an inorganic compound with the molecular formula Cl2O. It was first synthesised in 1834 by Antoine Jérôme Balard, who along with Gay-Lussac also determined its composition. In older literature it is often referred to as chlorine monoxide, which can be a source of confusion as that name now refers to the ClO• radical.
At room temperature it exists as a brownish-yellow gas which is soluble in both water and organic solvents. Chemically, it is a member of the chlorine oxide family of compounds, as well as being the anhydride of hypochlorous acid. It is a strong oxidiser and chlorinating agent.
Preparation
The earliest method of synthesis was to treat mercury(II) oxide with chlorine gas. However, this method is expensive, as well as highly dangerous due to the risk of mercury poisoning.
2 Cl2 + HgO → HgCl2 + Cl2O
A safer and more convenient method of production is the reaction of chlorine gas with hydrated sodium carbonate at 20–30 °C.
2 Cl2 + 2 Na2CO3 + H2O → Cl2O + 2 NaHCO3 + 2 NaCl
2 Cl2 + 2 NaHCO3 → Cl2O + 2 CO2 + 2 NaCl + H2O
This reaction can be performed in the absence of water but requires heating to 150–250 °C; as dichlorine monoxide is unstable at these temperatures it must therefore be continuously removed to prevent thermal decomposition.
2 Cl2 + Na2CO3 → Cl2O + CO2 + 2 NaCl
Structure
The structure of dichlorine monoxide is similar to that of water and hypochlorous acid, with the molecule adopting a bent molecular geometry (due to the lone pairs on the oxygen atom) and resulting in C2V molecular symmetry. The bond angle is slightly larger than normal, likely due to steric repulsion between the bulky chlorine atoms.
In the solid state, it crystallises in the tetrahedral space group I41/amd, making it isostructural to the high pressure form of water, ice VIII.
Reactions
Dichlorine monoxide is highly soluble in water, where it exists in an equilibrium with HOCl. The rate of hydrolysis is slow enough to allow the extraction of Cl2O with organic solvents such as CCl4, but the equilibrium constant ultimately favours the formation of hypochlorous acid.
2 HOCl ⇌ Cl2O + H2O K (0 °C) = 3.55x10−3 dm3/mol
Despite this, it has been suggested that dichlorine monoxide may be the active species in the reactions of HOCl with olefins and aromatic compounds, as well as in the chlorination of drinking water.
With inorganic compounds
Dichlorine monoxide reacts with metal halides, with the loss of Cl2, to form unusual oxyhalides.
VOCl3 + Cl2O → VO2Cl + 2 Cl2
TiCl4 + Cl2O → TiOCl2 + 2 Cl2
SbCl5 + 2 Cl2O → SbO2Cl + 4 Cl2
Similar reactions have also been observed with certain inorganic halides.
AsCl3 + 2 Cl2O → AsO2Cl + 3 Cl2
NOCl + Cl2O → NO2Cl + Cl2
With organic compounds
Dichlorine monoxide is an effective chlorinating agent. It can be used for either the side-chain or ring chlorination of deactivated aromatic substrates. For activated aromatics such as phenols and aryl-ethers it primarily reacts to give ring halogenated products. It has been suggested that dichlorine monoxide may be the active species in the reactions of HOCl with olefins and aromatic compounds.
Photochemistry
Dichlorine monoxide undergoes photodissociation, eventually forming O2 and Cl2. The process is primarily radical based, with flash photolysis showing radical hypochlorite (ClO·) to be a key intermediate.
2 Cl2O → 2 Cl2 + O2
Explosive properties
Dichlorine monoxide is explosive, although there is a lack of modern research into this behaviour. Room temperature mixtures with oxygen could not be detonated by an electric spark until they contained at least 23.5% Cl2O which is an exceedingly high minimum explosive limit. There are conflicting reports of it exploding on exposure to strong light. Heating above 120 °C, or a rapid rate of heating at lower temperatures also apparently lead to explosions.
Liquid dichlorine monoxide has been reported to be shock-sensitive.
References
Chlorine oxides
Gases with color
Explosive chemicals
Chlorine(I) compounds | Dichlorine monoxide | Chemistry | 1,002 |
18,616,845 | https://en.wikipedia.org/wiki/3%20mobile%20tv%20%28UK%29 | 3 in the UK offer a Mobile TV service across most of their range of phones. It is provided by 3 and independent companies and offers the main genres of: Comedy, Entertainment, Music, Documentaries, Kids programming and user-submitted content. Some channels adopt the branding of well-known channels such as MTV and Nickelodeon, but their programming consists of a repetitive loop that is typically refreshed once a week. This differs from the complete range of content offered by digital television and cable services.
Pricing
3 Mobile TV is available in 3 ways:
By pay-per-day for 49p. This gives 24 hours of unlimited access to all channels.
By buying a monthly add-on for £5. Open to Pay monthly (contract) customers only. This gives access to all channels for exactly 1 month.
By buying a PAYG Mobile TV add-on for £2. This gives access to a restricted service of 4 channels: ITV1, Kiss, Geek TV and MTV Trax. This add-on is valid for exactly 1 month.
Channel listing
Aardman Animations (exclusive, updated weekly)
ITV1 (live, but due to legal issues, is unable to show advertisement breaks or certain programmes, mostly sports and films)
FHM (updated weekly)
MTV Trax (music videos, updated daily)
MTV Snax (MTV non-music programming, updated weekly)
Nickeleodeon (children's programming, updated weekly)
Vidzone TV (music videos, exclusive, updated weekly)
Paramount Comedy (updated weekly)
Geek TV (comedy clips, cartoons and user-generated content, exclusive, updated weekly)
National Geographic (updated weekly)
Kerrang! (music videos, updated daily)
Kiss (music videos)
Former channels
Zone Reality
Six Degrees Extreme Sports
ITN
ITV Play
BBC1
BBC3
The BBC channels were broadcast on 3 for a trial period, and are not currently available.
Issues
All channels (except ITV1) must be re-connected to after 20 minutes to continue viewing.
ITV1 must be re-connected to after 30 minutes to continue viewing.
Most channels are updated weekly.
The only live channel is ITV1.
ITV 1 cannot show certain shows.
National Geographic shows merely clips of its programmes.
Currently offers no BBC channels.
A high ratio of music channels compared to other genres.
Related services
3 in the UK also offer a selection of "Free videos" or "Free to watch" content. These are funded by advertisements (Unlike mobile TV which has no commercial advertisements).
The main competitor is Sky Mobile TV, available on Vodafone UK, o2 UK and T-mobile UK. MobiTV, which used to be a competitor of Virgin Mobile, is no longer available in Europe as it has ceased its operations there.
References
External links
3 Mobile TV official site
Mobile telephone broadcasting | 3 mobile tv (UK) | Technology | 569 |
450,543 | https://en.wikipedia.org/wiki/Femtochemistry | Femtochemistry is the area of physical chemistry that studies chemical reactions on extremely short timescales (approximately 10−15 seconds or one femtosecond, hence the name) in order to study the very act of atoms within molecules (reactants) rearranging themselves to form new molecules (products). In a 1988 issue of the journal Science, Ahmed Hassan Zewail published an article using this term for the first time, stating "Real-time femtochemistry, that is, chemistry on the femtosecond timescale...". Later in 1999, Zewail received the Nobel Prize in Chemistry for his pioneering work in this field showing that it is possible to see how atoms in a molecule move during a chemical reaction with flashes of laser light.
Application of femtochemistry in biological studies has also helped to elucidate the conformational dynamics of stem-loop RNA structures.
Many publications have discussed the possibility of controlling chemical reactions by this method, but this remains controversial. The steps in some reactions occur in the femtosecond timescale and sometimes in attosecond timescales, and will sometimes form intermediate products. These reaction intermediates cannot always be deduced from observing the start and end products.
Pump–probe spectroscopy
The simplest approach and still one of the most common techniques is known as pump–probe spectroscopy. In this method, two or more optical pulses with variable time delay between them are used to investigate the processes happening during a chemical reaction. The first pulse (pump) initiates the reaction, by breaking a bond or exciting one of the reactants. The second pulse (probe) is then used to interrogate the progress of the reaction a certain period of time after initiation. As the reaction progresses, the response of the reacting system to the probe pulse will change. By continually scanning the time delay between pump and probe pulses and observing the response, workers can reconstruct the progress of the reaction as a function of time.
Examples
Bromine dissociation
Femtochemistry has been used to show the time-resolved electronic stages of bromine dissociation. When dissociated by a 400 nm laser pulse, electrons completely localize onto individual atoms after 140 fs, with Br atoms separated by 6.0 Å after 160 fs.
See also
Attosecond physics (1 attosecond = 10−18 s)
Femtotechnology
Ultrafast laser spectroscopy
Ultrashort pulse
Flash photolysis
References
Further reading
Femtochemistry: Ultrafast Dynamics of the Chemical Bond, Ahmed H Zewail, World Scientific, 1994
External links
Controlling and probing atoms and molecules with ultrafast laser pulses, PhD Thesis
Physical chemistry
Ultrafast spectroscopy
Articles containing video clips
Photochemistry | Femtochemistry | Physics,Chemistry | 571 |
16,770,099 | https://en.wikipedia.org/wiki/Nine%20Herbs%20Charm | The Nine Herbs Charm, Nigon Wyrta Galdor, Lay of the Nine Healing Herbs, or Nine Wort Spell (among other names) is an Old English charm recorded in the tenth century CE. It is part of the Anglo-Saxon medical compilation known as Lacnunga, which survives in the manuscript Harley MS 585 in the British Library. The charm involves the preparation of nine plants.
The poem contains one of two clear Old English mentions of the god Woden in Old English poetry; the other is Maxims I of the Exeter Book. Robert K. Gordon's translation of the section reads as follows:
Nine and three, numbers significant in Germanic paganism and later Germanic folklore, are mentioned frequently throughout the charm.
Scholars have proposed that this passage describes Woden coming to the assistance of the herbs through his use of nine twigs, each twig inscribed with the runic first-letter initial of a plant.
According to Gordon, the poem is "clearly an old heathen thing which has been subjected to Christian censorship." Malcolm Laurence Cameron states that chanting the poem aloud results in a "marvellously incantatory effect".
See also
Galdr
Hávamál
Mímir
Merseburg Incantations
Notes
References
Cameron, Malcolm Laurence (1993). Anglo-Saxon Medicine. Cambridge University Press.
Gordon, R. K. (1962). Anglo-Saxon Poetry. Everyman's Library #794. M. Dent & Sons, LTD.
Macleod, Mindy; Mees, Bernard (2006). Runic Amulets and Magic Objects. Boydell Press.
Mayr-Harting, Henry (1991). The Coming of Christianity to Anglo-Saxon England. Penn State Press
External links
Foys, Martin et al. Old English Poetry in Facsimile Project (Center for the History of Print and Digital Culture, University of Wisconsin-Madison, 2019-); digital facsimile edition and Modern English translation. Accessed February 2023.
Hopkins, Joseph S. 2020. "Nigon Wyrta Galdor: Popularly Known as the Nine Herbs Charm". Mimisbrunnr.info. Full text in normalised Old English with translations. Accessed February 2023.
Hostetter, Aaron K. 2023. "The Metrical Charms". Old English Poetry Project. Rutgers University-Camden. Accessed February 2023.
Jolly, Karen Louise. 1996. "Lay of the Nine Herbs and Lay of the Nine Twigs of Woden". Popular Religion in Late Saxon England: Elf Charms in Context (Chapel Hill: University of North Carolina Press, 1996), pp. 125-127.
Thomas, Val. 2022. "The Nine Herbs Charm: Plants Poisons and Poetry". Herbal History Research Network. Accessed February 2023.
Anglo-Saxon metrical charms
Biologically based therapies
Herbalism
Old English medicine
Pharmacognosy | Nine Herbs Charm | Chemistry | 589 |
20,341,849 | https://en.wikipedia.org/wiki/Teesside%20Steelworks | The Teesside Steelworks was a large steelworks that formed a continuous stretch along the south bank of the River Tees from the towns of Middlesbrough to Redcar in North Yorkshire, England. At its height there were 91 blast furnaces within a 10-mile radius of the area. By the end of the 1970s there was only one left on Teesside. Opened in 1979 and located near the mouth of the River Tees, the Redcar blast furnace was the second largest in Europe.
The majority of the steelworks, including the Redcar blast furnace, Redcar and South Bank coke ovens and the BOS plant at Lackenby closed in 2015. The Teesside Beam Mill and some support services still operate at the Lackenby part of the site.
On 1 October 2022, the Basic Oxygen Steelmaking (BOS) Plant at Lackenby was demolished in one of the largest single explosive demolition operations in the country in 75 years.
History
19th century Origins
Bolckow, Vaughan & Co
In 1850s, iron ore was discovered in near Eston in the Cleveland Hills of Yorkshire, by John Vaughan and his mining geologist John Marley. Vaughan and his partner Henry Bolckow, over the next decades, would build an iron and steel works, which extended, by 1864, over along the banks of the River Tees.
In 1875, Edward Windsor Richards became the General Manager of the Middlesbrough Ironworks. Richards was in charge of the design and construction of the new plant at Eston, the Cleveland Steel Works. It had three coke fired haematite blast furnaces. Richards' work helped to improve the Bessemer process for making steel, in the case when the ore is rich in phosphorus, and an alkaline rock (dolomite, limestone or magnesite) is used. This variant is called the Gilchrist–Thomas process after its inventor Sidney Gilchrist Thomas who persuaded Richards to adopt it.
The firm later acquired the Southbank Steelworks and adopted the Gilchrist–Thomas process at the suggestion of its developer, Sidney Gilchrist Thomas. This allowed the use of local ironstone which had a high phosphorus content. Bolckow, Vaughan & Co Ltd were already well established producers of Iron owning many Ironworks and furnaces and were seen as the driving force behind the rapid expansion of Middlesbrough or "Ironopolis" and Great Britain's leading producer of pig iron. After the company's acquisition of the Clay Lane works at the end of the century and a shift in production from Iron to steel they became the largest producers of steel in Great Britain and possibly the world, owning 21 of the 91 blast furnaces in the Cleveland area.
Dorman Long
In 1876, Arthur Dorman entered into a partnership with Albert de Lande Long to form Dorman Long, taking over the West Marsh Ironworks in Middlesbrough. Over next 10 years Dorman Long would expand further, acquiring the Brittania works in Middlesbrough, and building a new steel works at the Clarence works in a joint venture with Bell Brothers.
Other developments
The amount of slag coming out of the various furnaces of Teesside increased substantially and its disposal became a costly problem for works' owners. One solution, invented in the 1870s, was the Scoria brick which became a major export of the region and can still widely be seen as a road surface in the local area.
20th century expansion
In 1902, Dorman Long would build the first integrated steelworks at Cargo Fleet. In the following year, Lowthian Bell, then aged 87, sold a majority holding of the Bell companies to the rivals Dorman Long.
During the First World War Dorman Long was one of the first non-munitions company in Britain to dedicate itself to shell production. By 1917, they had completed a new blast furnace at Redcar with a cost of £5.4 million. Some of the steel produced here, along with steel from the Brittania and Cargo Fleet steelworks, would be used to build notable structures including the Sydney Harbour Bridge, Tyne Bridge, in the 20s, and later, the Auckland Harbour Bridge.
Interwar period
In 1923, Bolckow, Vaughan & Co acquired Redpath, Brown & Co, manufacturers of structural steel.
As the 1920s went on Bolckow Vaughan found itself in an increasingly difficult financial situation. The works were reorganised, and consultation with the workforce introduced. The causes of these problems included: poor decision-making in the period from 1900–1910 which delayed the introduction of improved steelmaking technology; optimistic belief in promises of funding made by the British government during the war, leading to reliance on costly bank loans in 1918; and failure to invest in its own coal mines to provide enough for steel production, and for cash. By 1929, the financial pressures, forced the company into a takeover by Dorman Long who by this point is also struggling financially.
In 1946, The Lackenby development was built by Dorman Long between the Redcar and Cleveland Works.
Nationalisation
In 1967, Dorman Long was absorbed into the newly created nationalised company, British Steel Corporation.
In 1979, the new blast furnace opened at the former Redcar site using the open hearth process. It was the second largest of its kind in Europe and Teesside's sole remaining blast furnace, at that time.
Privatisation and decline
In 1988, British Steel was re-privatised to form British Steel plc. In 1999, British Steel plc merged with Netherlands-based steel maker Koninklijke Hoogovens to form Corus Group. Corus utilised the site for basic oxygen steelmaking, using iron produced at the company's Redcar blast furnace.
By 2003, Corus considered that the production at Teesside Cast Products (TCP) as a surplus to its needs. Corus was bought by Tata Steel, in 2007.
In 2009, Corus announced partial mothballing of the Teesside blast furnace. Approx. 1,700 jobs eliminated. To help the workers, a Corus Response Group was formed which developed a comprehensive package of support. This plan was in place over the past 10 months of announcement and included employment experts on site from January 2010. Support was put in place to help affected workers with individual sessions to update CVs, highlight job opportunities and look at retraining options. The response group was also supposed to work with the Teesside Cast Products function to offer similar support.
SSI
On 24 February 2011, the steelworks was purchased by Thai-based Sahaviriya Steel Industries (SSI) at $469 million. The acquisition was expected to create more than 800 jobs on top of the existing workforce of 700 and the plant was officially reopened 15 April 2012.
On 18 September 2015, production was paused due to the global decline in steel prices.
On 28 September 2015, the plant was mothballed again amid poor steel trading conditions across the world and a drop in steel prices.
On 2 October, SSI UK entered into liquidation.
On 12 October 2015, the receiver announced there was no realistic prospect of finding a buyer. The coke ovens were scheduled for extinguishing, however this time it was done without the complex decommissioning processes conducted in 2010, which would have allowed the facility to reopen in the future.
British Steel
The remainder of the site is still operational (Teesside Beam Mill and ancillary support services at Lackenby and the deep-water bulk handling terminal), having been sold by Tata Steel to investment firm Greybull Capital on 1 June 2016. As part of the deal, the historic British Steel name was resurrected. The new company includes the UK sites at Skinningrove and Scunthorpe as well as the Hayange rail plant in northern France.
Insolvency of British Steel
In May 2019 British Steel collapsed and was taken over by the Insolvency Service. It was later purchased in March 2020 by Jingye Group, who agreed to save the remaining jobs by modernising the steelworks.
Electric Arc Furnace plans
In April 2024, British Steel won planning permission for an electric arc furnace to be built at the remaining Lackenby site. There is however no clear timetable for the actual construction of the structure.
Demolition and Redevelopment
The steelworks' BOS plant, blast furnace, and power station, along with auxiliary structures, were demolished in between October 2022 and June 2023, creating a 4,500-acre site of brownfield land.
This is to be regenerated as Teesworks, an industrial zone and freeport project.
Environmental aspects
The closure of the steelworks, coupled with the running down of many coal-fired power stations and a UK Government carbon tax, led to a 6% reduction in carbon emissions from the United Kingdom in 2016.
Transport
The site is situated alongside the A66 and A1085 dual carriageways. Main access is via the Lackenby and Redcar entrances, situated on the A1085.
The site is adjacent to Teesport that was used for iron ore, coal, and other raw material imports, and steel exports.
The site was served by the Redcar British Steel railway station, which opened on 19 June 1978. Northern discontinued service to the station in December 2019, prior to this the station (owned by Network Rail), was surrounded by private land, which prevented any public access to or from the station.
See also
Billingham Manufacturing Plant
Darlington Works
Hopetown Carriage Works
Darlington TMD
Billingham Manufacturing Plant
Bowesfield Works
References
External links
Tata Steel Europe
Buildings and structures in Redcar and Cleveland
Buildings and structures in North Yorkshire
Ironworks and steelworks in England
Redcar | Teesside Steelworks | Chemistry | 1,961 |
1,146,140 | https://en.wikipedia.org/wiki/Ganz%20Works | The Ganz Machinery Works Holding is a Hungarian holding company. Its products are related to rail transport, power generation, and water supply, among other industries.
The original Ganz Works or Ganz ( or , Ganz companies, formerly Ganz and Partner Iron Mill and Machine Factory) operated between 1845 and 1949 in Budapest, Hungary. It was named after Ábrahám Ganz, the founder and manager of the company. Ganz is probably best known for the manufacture of tramcars, but was also a pioneer in the application of three-phase alternating current to electric railways.
Ganz also made ships (through its Ganz Danubius division), bridge steel structures (Ganz Acélszerkezet) and high-voltage equipment (Ganz Transelektro). In the early 20th century the company experienced its heyday and became the third-largest industrial enterprise in the Kingdom of Hungary after the Manfréd Weiss Steel and Metal Works and the MÁVAG company.
Since 1989, various parts of Ganz have been taken over by other companies.
History
The company was founded by Ábrahám Ganz in 1844. He was invited to Pest, Hungary, by Count István Széchenyi and became the casting master at the Roller Mill Plant (referred to as Hengermalom in Hungarian). In 1854 he began manufacturing hard cast railroad wheels in his own plant founded in 1844. The management of the steam mill paid a share of the profit to Ganz. This enabled him to buy, in 1844, land and a house for 4500 Forints in Víziváros, Buda castle district. Abraham Ganz built his own foundry on this site and started to work there with seven assistants. They made mostly casting products for the needs of the people of the city.[3] In 1845, he bought the neighbouring site and expanded his foundry with a cupola furnace. He gave his brother, Henrik a job as a clerk, because of the growing administration work. He made a profit in the first year, and his factory grew, even though he had not yet engaged in mass production. In 1846, at the third Hungarian Industrywork Exhibition (Magyar Iparmű Kiállítás), he introduced his stoves to the public. He won the silver medal of the exhibition committee and the bronze medaille from Archduke Joseph, Palatine of Hungary.
During the Hungarian Revolution of 1848 the foundry made ten cannons and many cannonballs for the Hungarian army. Because of this, the Military Court of Austria impeached him. He got seven weeks in prison as penalty, but because of his Swiss citizenship he was acquitted of the charge.[3]
Ganz recognized that, to develop his factory, he had to make products that were mass-produced. In 1846 the Pest-Vác railway line was built. At that time, European foundries made wrought iron rims for spoked wagon wheels by pouring the casts in shapes in sand, and leaving them to cool down. He successfully developed a railway wheel casting technology; it was the new method of "crust-casting" to produce cheap yet sturdy iron railway wheels, which greatly contributed to the rapid railway development in Central Europe. 86,074 pieces of hard cast wheels had been sold to 59 European railway companies until 1866. Consequently, this factory played an important role in building the infrastructure of the Hungarian Kingdom and the Austro-Hungarian Empire. At this time the agricultural machines, steam locomotives, pumps and the railway carriages were the main products. At the beginning of the 20th century, 60 to 80% of the factory's products were sold for export.
After the death of Abraham Ganz, the heirs entrusted the management of the factory to his direct colleagues at Ganz Művek: Antal Eichleter, Ulrik Keller and Andreas Mechwart, which then took the name Ganz & Co. The Ganz family sold the company, which consisted of five departments, and in April 1869 it was transformed into a joint-stock company, and continued its operations under the name of "Ganz és Társa vasontöde és Gépgyár Rt." (Ganz & Partners Iron Foundry and Machine Factory Co.) The technical director was András Mechwart, under whose direction Ganz became one of the most important groups of machine building companies in the Austro-Hungarian Monarchy after 1869.
At the end of the 19th century, the products of the Ganz and Partner Iron Mill and Machine Factory (hereinafter referred to as Ganz Works) promoted the expansion of alternating-current power transmissions.
Prominent engineers
Prominent engineers at Ganz works included András Mechwart, Károly Zipernowsky, Miksa Déri, Ottó Titusz Bláthy, Kálmán Kandó, György Jendrassik and Ernő Wilczek.
Revolution in the milling industry
The invention of the modern industrial mill (the roller mill ) – by András Mechwart in 1874 – guaranteed a solid technological superiority and revolutionized the world's milling industry. Budapest's milling industry grow the second largest in the world, behind the American Minneapolis. The Hungarian grain export increased by 66% within some years.
Power plants, generators turbines and transformers
In 1878, the company's general manager András Mechwart founded the Department of Electrical Engineering headed by Károly Zipernowsky. Engineers Miksa Déri and Ottó Bláthy also worked at the department producing direct-current machines and arc lamps.
In 1878, the company began producing equipment for electric lighting and, by 1883, had installed over fifty systems in Austria-Hungary. Their AC systems used arc and incandescent lamps, generators, and other equipment.
Generators
The first turbo generators were water turbines which drove electric generators. The first Hungarian water turbine was designed by engineers of the Ganz Works in 1866. Mass production of dynamo generators started in 1883.
The missing link of a full Voltage Sensitive/Voltage Intensive (VSVI) system was the reliable alternating current constant voltage generator. Therefore, the invention of the constant voltage generator by the Ganz Works in 1883 had a crucial role in the beginnings of industrial scale AC power generation, because only these type of generators can produce a stable output voltage, regardless of the actual load.
Transformers
In cooperation, Zipernovsky, Bláthy and Déri (known as the ZBD team) constructed and patented the transformer. The "transformer" was named by Ottó Titusz Bláthy. The three invented the first high efficiency, closed core shunt connection transformer. They also invented the modern power distribution system: Instead of a series of connections they connected supply transformers in parallel to the main line.
The transformer patents described two basic principles. Loads were to be connected in parallel, not in series as had been the general practice until 1885. Additionally, the inventors described the closed armature as an essential part of the transformer. Both factors assisted the stabilisation of voltage under varying load, and allowed definition of standard voltages for distribution and loads. The parallel connection and efficient closed core made construction of electrical distribution systems technically and economically feasible.
The Ganz Works built the first transformers using iron plating of enamelled mild iron wire, and started to use laminated cores to eliminate eddy currents
AC Power stations
In 1886, the ZBD engineers designed, and the company supplied, electrical equipment for the world's first power station to use AC generators to power a parallel connected common electrical network. This was the Italian steam-powered Rome-Cerchi power plant.
Following the introduction of the transformer, the Ganz Works changed over to production of alternating-current equipment. For instance, Rome's electricity was supplied by hydroelectric plant and long-distance energy transfer.
Electricity meters
The first mass-produced kilowatt-hour meter (electricity meter), based on Hungarian Ottó Bláthy's patent and named after him, was presented by the Ganz Works at the Frankfurt Fair in the autumn of 1889, and the company was marketing the first induction kilowatt-hour meter by the end of the year. These were the first alternating-current wattmeters, known by the name of Bláthy-meters.
Industrial refrigerators and air conditioners
In 1894, Hungarian inventor and industrialist István Röck started to manufacture a large industrial ammonia refrigerator (together with the Esslingen Machine Works) which was powered by Ganz electric compressors. At the 1896 Millennium Exhibition, Röck and the Esslingen Machine Works presented a 6-tonne capacity artificial ice producing plant. In 1906, the first large Hungarian cold store (with a capacity of 3,000 tonnes, the largest in Europe) opened in Tóth Kálmán Street, Budapest, the machine was manufactured by the Ganz Works. Until nationalisation after the Second World War, large-scale industrial refrigerator production in Hungary was in the hands of Röck and Ganz Works.
The contract between Ganz and Egypt in the 1930s played a key role in the development of cooling equipment: railcars delivered to Egypt were equipped with air-conditioning cooling systems. The collective of the Ganz factory (machine designers: Gábor Hollerung, Rezső Oláh, István Pfeifer, Prónai) designed and built the 3-cylinder, 20 kW compressors with freon refrigerant, air condenser and evaporator. The machine could also be converted to heat pump operation.
ICE engines and vehicles
The beginning of gas engine manufacturing in Hungary is linked to Donát Bánki and János Csonka but it is not clear that they ever worked for Ganz.
Ganz produced engines whose designs were licensed to Western European partners, notably in the United Kingdom and Italy.
Timeline
1889 the first four-stroke gas engine was built by the Ganz factory
1893 the manufacture of paraffin and petrol fuelled engine with carburetor
1898 the manufacture of engines with the Bánki water injection system
1908 the introduction of a new petrol engine type, the series Am
1913 the manufacture of Büssing petrol engines for trucks
1914–18 the manufacture of fighter plane engines
1916 the manufacture of petrol engines, type Fiat
1920 the modification of petrol engines for suction gas operation
1924 György Jendrassik started his engine development activity
1928 the first railway diesel engine was completed, according to the plans of Ganz-Jendrassik
1929 the first export delivery of a railway engine using the system of Ganz-Jendrassik
1934 there was an engine reliability World Competition in the USSR where the Ganz engine achieved the best fuel consumption in its category
1939 Scale model of Ganz Ac Electric locomotive exhibited at the Italy Pavilion of the New York World's Fair
1939–42 construction of the Jendrassik Cs-1 turboprop engine
1944 the first application of the engine type XII JV 170/240 in a motor-train set
1953 modernisationon of the diesel engine system Ganz-Jendrassik
1959 the union of the Ganz factory and the MÁVAG company, establishing Ganz-MÁVAG
Railways
Steam motors
The Ganz Company started to construct steam locomotives and steam railcars from the 1860s.
Between 1901 and 1908, Ganz Works of Budapest and de Dion-Bouton of Paris collaborated to build a number of railcars for the Hungarian State Railways together with units with de Dion-Bouton boilers, Ganz steam motors and equipments, and Raba carriages built by the Raba Hungarian Wagon and Machine Factory in Győr. In 1908, the Borzsavölgyi Gazdasági Vasút (BGV), a narrow-gauge railway in Carpathian Ruthenia (today's Ukraine), purchased five railcars from Ganz and four railcars from the Hungarian Royal State Railway Machine Factory with de Dion-Bouton boilers. The Ganz company started to export steam motor railcars to the United Kingdom, Italy, Canada, Japan, Russia and Bulgaria.
The World's first electrified main railway line in Italy
The Ganz Works, having identified the significance of induction motors and synchronous motors, commissioned Kálmán Kandó to develop them. In 1894, Hungarian engineer Kálmán Kandó developed high-voltage three-phase AC motors and generators for electric locomotives. The first-ever electric rail vehicle manufactured by Ganz Works was a 6 HP pit locomotive with direct current traction system. The first Ganz made asynchronous rail vehicles (altogether 2 pieces) were supplied in 1898 to Évian-les-Bains (France) with a 37 HP asynchronous traction system. The Ganz Works won the tender for electrification of the Valtellina Railway in Italy in 1897. Under the management, and on the basis of plans from Kálmán Kandó, three phase electric power at 3 kV and 15 Hz was fed through two upper wires and the rails.
The electricity was produced in a dedicated power station and the system operated for thirty years from 1902. Italian railways were the first in the world to introduce electric traction for the entire length of a main line rather than just a short stretch. The 106 km Valtellina line was opened on 4 September 1902, designed by Kandó and a team from the Ganz works. The voltage was significantly higher than used earlier and it required new designs for electric motors and switching devices. The three-phase two-wire system was used on several railways in Northern Italy and became known as "the Italian system". Kandó was invited in 1905 to undertake the management of Società Italiana Westinghouse and led the development of several Italian electric locomotives.
Invention of the Phase Converter
In 1918, Kandó invented and developed the rotary phase converter, enabling electric locomotives to use three-phase motors whilst supplied via a single overhead wire, carrying the simple industrial frequency (50 Hz) single phase AC of the high-voltage national networks.
After World War I, at the Ganz Works, Kálmán Kandó constructed a single-phase electric railway system using 16 kV at 50 Hz. A similar system, but using 15 kV at 16.7 Hz, later became widely used in Europe. The main attribute of Kandó's 50 Hz system was that it was fed by the normal power network, so dedicated railway power stations became unnecessary. Because of the early death of Kálmán Kandó, László Verebélÿ continued the work for the Hungarian State Railways (MÁV).
Ganz-MÁVAG rail rolling stock
In 1959 Ganz merged with the MÁVAG company and was renamed Ganz-MÁVAG.
In 1976 Ganz-Mávag supplied ten standard gauge 3-car diesel trainset to the Hellenic Railways Organisation (OSE), designated as Class AA-91 and four metre gauge 4-car trainsets, designated as Class A-6451. In 1981/82 Ganz-Mávag supplied to OSE 11 B-B diesel-hydraulic DHM7-9 locomotives, designated as class A-251. Finally, in 1983, OSE bought eleven 3-car metre gauge trainsets, designated as Class A-6461. All these locomotives and trainsets have been withdrawn with the exception of one standard and one metre gauge trainset.
In 1982/83 Ganz-Mávag supplied an order for electric multiple units to New Zealand Railways Corporation for Wellington suburban services. The order was made in 1979, and was for 44 powered units and 44 trailer units, see New Zealand EM class electric multiple unit.
Ganz-MÁVAG Trams
Ganz-MÁVAG delivered 29 trams (2 car sets) to Alexandria, Egypt from 1985 to 1986.
Shipbuilding, Ganz - Danubius
In 1911, the Ganz Company merged with the Danubius shipbuilding company, which was the largest shipbuilding company in Hungary. From 1911, the unified company adopted the "Ganz–Danubius" brand name. In the beginning of the 20th century the company had 19 shipyards on the Danube and the Adriatic Sea in the city of Rijeka and Pula.
As Ganz Danubius, the company became involved in shipbuilding before, and during, World War I. Ganz was responsible for building the dreadnought , all of the Novara-class cruisers, and built diesel-electric U-boats at its shipyard in Budapest, for final assembly at Fiume. Several U-boats of the U-XXIX class, U-XXX class, U-XXXI class and U-XXXII class were completed, A number of other types were laid down, but remained incomplete at the war's end. By the end of the First World War, 116 naval vessels had been built by The Ganz-Danubius company. The company also produces transatlantic ocean liners for passenger lines Trieste - New York, Trieste - Montevideo, as a reflection of already formed wave of mass migration from Central Europe to America.
Aircraft
The first Hungarian "aeroplane factory" ( UFAG ) was founded by the Ganz Company and Weiss-Manfréd Works in 1912. During World War I, the company made many types of Albatros and Fokker fighter planes.
Before 1919, the company built ocean liners, dreadnought type battleships and submarines, power plants, automobiles and many types of fighter aircraft.
The world's first turboprop engine was the Jendrassik Cs-1 designed by the Hungarian mechanical engineer György Jendrassik. It was built and tested in the Ganz factory in Budapest between 1939 and 1942. It was planned to be fitted to the Varga RMI-1 X/H twin-engined reconnaissance bomber designed by László Varga in 1940, but the program was cancelled. Jendrassik had also designed a small-scale 75 kW turboprop in 1937.
After World War II
In 1947, the Ganz Works was nationalised and in 1949 it became independent and six big companies came into existence, including the Ganz Transformer Factory. In 1959, Ganz Wagon and Machine Factory merged with the MÁVAG Locomotive and Machine Factory under the name of Ganz-MÁVAG Locomotive, Wagon and Machine Works. Of the products of the Works, outstanding results were shown in the field of the manufacture of diesel railcars and multiple units. Traditional products included tramcars as well, and customers included the tramway network of Budapest. In the meantime the Foundry workshop was closed down.
In 1974, the locomotive and wagon Works were merged under the name of Railway Vehicle Factory and then the machine construction branch went through significant development. The production of industrial and apartment house lifts became a new branch. Ganz-MÁVAG took over a lot of smaller plants in the 1960s and 1970s and their product range was extended. Among other things, they increased their bridge-building capacity. They made iron structures for several Tisza bridges, for the Erzsébet Bridge in Budapest, for public road bridges in Yugoslavia and for several industrial halls.
The Ganz Shipyard experienced its most productive times during the four decades following nationalisation. In the course of this period 1100 ship units were produced, the number of completed seagoing ships was 240 and that of floating cranes was 663. As a result of the great economic and social crises of the 1980s, Ganz-MÁVAG had to be reorganised. The company was transformed into seven independent Works and three joint ventures.
Ganz since 1989
In 1989, the British company Telfos Holdings gained a majority of the shares in Ganz Railway Vehicle Factory Co. Ltd. and the name of the company was changed to Ganz-Hunslet Co. Ltd. In the course of 1991 and 1992, the Austrian company Jenbacher Werke obtained 100% of the company's shares and consequently the railway vehicle factory is now a member of the international railway vehicle manufacturing group, Jenbacher Transport Systeme. At present, the Ganz Electric Works, under the name of Ganz-Ansaldo is a member of the Italian industrial giant, AnsaldoBreda. The Ganz Works were transformed into holdings. Ganz-Danubius was wound up in 1994. The Ganz Electric Meter Factory in Gödöllő became the member of the international Schlumberger group.
In 2006, the power transmission and distribution sectors of Ganz Transelektro were acquired by Crompton Greaves, but still doing business under the Ganz brand name, while the unit dealing with electric traction (propulsion and control systems for electric vehicles) was acquired by Škoda Transportation and is now a part of Škoda Electric.
Now the plant is operated by a new investor as a tenant, Ganz Transformer Motor and Manufacturing Ltd., after the previous owner was unable to finance the production.
Timeline
1991: Joint Venture with Italian Ansaldo named Ganz Ansaldo Ltd.
1994: Air-cooled turbogenerator from 20 up to 70MVA
1998: Development of double-cage induction motor for twin-drives first on the world
2000: Acquisition by Tranelektro Group under name of Ganz-Transelektro
2001: Developed 1MW ExN Non-sparking gasturbine starter motors for GE
2002: First transformer in the world for 123 kV with ester liquid
2006: Became a Part of Crompton Greaves Ltd as CG Electric Systerms Hungary
2010: Start of manufacturing Safety Class 3&4 motors for Nuclear Power Plants
2018: Developing VFD-driven Increased Safety LVAC motors for driving OEM pumps used in Oil&gas fields
2020: Establishment of Ganz Transformer Motor and Generator Ltd., Ganz brand back in Hungarian ownership
Divisions
Source:
Transformer division
The Transformer division specializes in the design, manufacture and testing of substation transformers, generation transformers, auxiliary transformers, mobile transformers and traction transformers from 20 to 600 MVA (1000 MVA for autotransformers) from 52 to 800 kV.
Rotating machines division
The production of three-phase, alternating current induction motors began in the factory in 1894. Through the 90's Ganz has developed more advanced motors with decreased total weight, increased efficiency and low noise levels in order to satisfy the actual needs of the market and all conditions of the industrial application and to conform to IEC, NEMA, ATEX and EAC standards.
GIS Service Division
GIS Service division performs onsite works like maintenance, inspection, modification, overhaul, extensions on former GANZ and other brands of switchgears. The activity is mainly focused on the existing substations and equipment.
References
External links
– Ganz Machinery Works Holding, current company
A photo of a Ganz railcar of Hungarian State Railways c1936
A withdrawn Ganz-Mavag DMU at Mendoza, Argentina
Ganz Transelektro Ltd's page in English
Ganz Danubius homepage
Rolling stock manufacturers of Hungary
Hungarian brands
Tram manufacturers
Companies of Austria-Hungary
Motor vehicle manufacturers of Austria-Hungary
Shipbuilding companies of Austria-Hungary
Manufacturing companies established in 1844
1844 establishments in the Austrian Empire
Electrical engineering companies
Avantha Group | Ganz Works | Engineering | 4,694 |
1,403,889 | https://en.wikipedia.org/wiki/Ultraparallel%20theorem | In hyperbolic geometry, two lines are said to be ultraparallel if they do not intersect and are not limiting parallel.
The ultraparallel theorem states that every pair of (distinct) ultraparallel lines has a unique common perpendicular (a hyperbolic line which is perpendicular to both lines).
Hilbert's construction
Let and be two ultraparallel lines.
From any two distinct points and on s draw and perpendicular to with and on .
If it happens that AB = CB', then the desired common perpendicular joins the midpoints of AC and BB' (by the symmetry of the Saccheri quadrilateral ACB'B).
If not, we may suppose AB < CB' without loss of generality. Let E be a point on the line s on the opposite side of A from C. Take A' on CB' so that A'B' = AB. Through A' draw a line s' (A'E') on the side closer to E, so that the angle B'A'E' is the same as angle BAE. Then s' meets s in an ordinary point D'. Construct a point D on ray AE so that AD = A'D'.
Then D' ≠ D. They are the same distance from r and both lie on s. So the perpendicular bisector of D'D (a segment of s) is also perpendicular to r.
(If r and s were asymptotically parallel rather than ultraparallel, this construction would fail because s' would not meet s. Rather s' would be limiting parallel to both s and r.)
Proof in the Poincaré half-plane model
Let
be four distinct points on the abscissa of the Cartesian plane. Let and be semicircles above the abscissa with diameters and respectively. Then in the Poincaré half-plane model HP, and represent ultraparallel lines.
Compose the following two hyperbolic motions:
Then
Now continue with these two hyperbolic motions:
Then stays at , , , (say). The unique semicircle, with center at the origin, perpendicular to the one on must have a radius tangent to the radius of the other. The right triangle formed by the abscissa and the perpendicular radii has hypotenuse of length . Since is the radius of the semicircle on , the common perpendicular sought has radius-square
The four hyperbolic motions that produced above can each be inverted and applied in reverse order to the semicircle centered at the origin and of radius to yield the unique hyperbolic line perpendicular to both ultraparallels and .
Proof in the Beltrami-Klein model
In the Beltrami-Klein model of the hyperbolic geometry:
two ultraparallel lines correspond to two non-intersecting chords.
The poles of these two lines are the respective intersections of the tangent lines to the boundary circle at the endpoints of the chords.
Lines perpendicular to line l are modeled by chords whose extension passes through the pole of l.
Hence we draw the unique line between the poles of the two given lines, and intersect it with the boundary circle; the chord of intersection will be the desired common perpendicular of the ultraparallel lines.
If one of the chords happens to be a diameter, we do not have a pole, but in this case any chord perpendicular to the diameter it is also perpendicular in the Beltrami-Klein model, and so we draw a line through the pole of the other line intersecting the diameter at right angles to get the common perpendicular.
The proof is completed by showing this construction is always possible:
If both chords are diameters, they intersect.(at the center of the boundary circle)
If only one of the chords is a diameter, the other chord projects orthogonally down to a section of the first chord contained in its interior, and a line from the pole orthogonal to the diameter intersects both the diameter and the chord.
If both lines are not diameters, then we may extend the tangents drawn from each pole to produce a quadrilateral with the unit circle inscribed within it. The poles are opposite vertices of this quadrilateral, and the chords are lines drawn between adjacent sides of the vertex, across opposite corners. Since the quadrilateral is convex, the line between the poles intersects both of the chords drawn across the corners, and the segment of the line between the chords defines the required chord perpendicular to the two other chords.
Alternatively, we can construct the common perpendicular of the ultraparallel lines as follows: the ultraparallel lines in Beltrami-Klein model are two non-intersecting chords. But they actually intersect outside the circle. The polar of the intersecting point is the desired common perpendicular.
References
Karol Borsuk & Wanda Szmielew (1960) Foundations of Geometry, page 291.
Articles containing proofs
Hyperbolic geometry
Theorems in geometry | Ultraparallel theorem | Mathematics | 1,012 |
18,603,085 | https://en.wikipedia.org/wiki/Planetarium%20Science%20Center | The Planetarium Science Centre (PSC) is a department in the Bibliotheca Alexandrina located in Alexandria, Egypt. It promotes science centers as an educational tool.
Structure
Pre-Historic Animal Park
The Science Park has a Dinosaur Park that houses models of many prehistoric animals.
ALEXPloratorium
The ALEXPloratorium is located next to the Planetarium, where visitors can interact with multiple exhibits that cover various scientific topics, most commonly physics and astronomy.
Programs and events
The PSC's Remote Sensing Workshop program introduces the scientific principles of remote sensing and offers hands-on applications. The RoboAlex Center at the Alexploratorium offers instruction in robotics. The participating groups design, program, and test robots on a playing field to accomplish certain missions. The result of an alliance between FIRST and LEGO is the FIRST Lego League Challenge (FLL). The FLL is an international hands-on, sport-like robotics program that was intended for children aged 9–14.
Eratosthenes
Eratosthenes is an annual festival that the Bibliotheca Alexandrina organizes to promote science and heritage among school students. The Festivities of 2003–2008 evolved around measuring the Earth's circumference, inspired by the Greek mathematician and poet Eratosthenes.
Intel BASEF
The PSC, in collaboration with Intel, organizes the Intel Bibliotheca Alexandrina Science and Engineering Fair (Intel BASEF), which is hosted by the Bibliotheca Alexandrina in March. Intel BASEF is intended for children in grades 9–12 from Alexandria and the neighboring governorates to compete with each team. The winning projects, one team project and two individual projects, represent Egypt in the Intel International Science and Engineering Fair (Intel ISEF) that takes place in the United States.
Renovation
In 2009, the Bibliotheca Alexandrina reopened its planetarium after a renovation. The renovation included a new dome projection system and a new set of shows. The renovation allowed for the Bibliotheca and the Planetarium Science Center to jointly host the 20th International Planetarium Society conference in June 2010. "Stars of the Pharaohs" is one of the shows that was displayed at the PSC; it was based on ancient Egyptian astronomy. It discusses topics such as how the Ancient Egyptians built observatories to study astronomy and what their legacy is to modern science. "New Horizons" is a show focusing on modern astronomical discoveries.
The Digistar 3 was first introduced in 2002 by the Evans & Sutherland (E&S) Company, which specializes in digital systems for planetariums. The Digistar 3 uses two projectors to display the full hemisphere of the planetarium.
See also
List of planetariums
Bibliotheca Alexandrina
Library of Alexandria
International Planetarium Society
References
External links
Planetarium Science Center official website
Intel Bibliotheca Alexandria Science and Engineering Fair official website
Buildings and structures in Alexandria
Science and technology in Egypt
Scientific organisations based in Egypt
Bibliotheca Alexandrina
Planetaria | Planetarium Science Center | Astronomy | 627 |
399,675 | https://en.wikipedia.org/wiki/Reboot%20%28fiction%29 | In serial fiction, the term "reboot" signifies a new start to an established fictional universe, work, or series. A reboot usually discards continuity to re-create its characters, plotlines and backstory from the beginning. It has been described as a way to "rebrand" or "restart an entertainment universe that has already been established".
Another definition of a reboot is a remake which is part of an established film series or other media franchise. The term has been criticized for being a vague and "confusing" "buzzword", and a neologism for remake, a concept which has been losing popularity since the 2010s. William Proctor proposes that there is a distinction between reboots, remakes and retcons.
Origin
The term is thought to originate from the computing term reboot, meaning to restart a computer system. There is a change in meaning: the computing term refers to restarting the same program unaltered, while the term discussed here refers to revising a narrative from the beginning. The first known use of reboot applied to an entertainment franchise was in a 1994 Usenet posting.
Types
Reboots cut out non-essential elements associated with a pre-established franchise and start it anew, distilling it down to the core elements that made the source material popular. For audiences, reboots allow easier entry for newcomers unfamiliar with earlier titles in a series.
Comic books
In comic books, a long-running title may have its continuity erased to start over from the beginning, enabling writers to redefine characters and open up new story opportunities, allowing the title to bring in new readers. Comic books sometimes use an in-universe explanation for a reboot, such as merging parallel worlds and timelines together, or destroying a fictional universe and recreating it from the beginning.
Film
With reboots, filmmakers revamp and reinvigorate a film series to attract new fans and stimulate revenue. A reboot can renew interest in a series that has grown stale. Reboots act as a safe project for a studio, since a reboot with an established fanbase is less risky (in terms of expected profit) than an entirely original work, while at the same time allowing the studio to explore new demographics.
Television
A television series can return to production after cancellation or a long hiatus. Whereas a reboot disregards the previous continuity of a work, the term has also been used as a "catch all" phrase to categorize sequel series or general remakes due to the rise of such productions in the late 2010s.
A related concept is retooling, which is used to substantially change the premise of a series while keeping some of the core characters. Retools are usually part of an effort to forestall cancellation of a still running production.
Video games
Reboots and remakes are common in the video game industry. Remakes in video games are used to refresh the storyline and elements of the game and to take advantage of technology and features not available at the time of earlier entries.
Soft reboot
A soft reboot is a reboot that shares some continuity with the original series, but that changes the style, tone, or intent. It usually serves to allow writers more creative freedom while mostly maintaining the same setting the audience has grown accustomed to.
The Gritty Reboot
In the 21st century, the notion of the "gritty reboot" gained popularity, in which various franchises that often had a lighter tone in their original form were remade in a darker and more mature form. Christopher Nolan's Dark Knight Trilogy is one of the earlier, more famous, and highly regarded example, and was followed by gritty reboots of DC's Justice League, the James Bond franchise with Casino Royale in 2006, and other including Bel-Air and A Christmas Carol, among many other examples.
See also
Artistic license
Canon (fiction)
Prequel
Reset button technique
References
Comics terminology
Continuity (fiction)
Film and video terminology
Television terminology
Video game terminology | Reboot (fiction) | Technology | 813 |
13,896,453 | https://en.wikipedia.org/wiki/Odfjell%20Drilling | Odfjell Drilling Ltd. is an oil drilling, well service, and engineering company.
Current operations
The company has 3 divisions:
Mobile Offshore Drilling - Owns 6 drillships and operates in Norway, United Kingdom, Angola, Vietnam, and Brazil.
Drilling & Technology - provides platform drilling, project management and engineering services from offices in Bergen, Stavanger, and Aberdeen.
Well Services - provides casing and tubing running services (TRS), drill tool rental, and well intervention services to the onshore and offshore oil and gas industry.
History
The company was established in 1973 as an affiliate of Odfjell. In 1974, the first rigs were delivered from Aker ASA, and started service for ELF and Saga Petroleum. The first production drilling contract was awarded by Statoil on the Statfjord oil field in 1979. In 1984, the company expanded to the United Kingdom with a semi-submersible rig for Hamilton Brothers Oil & Gas. In 1989 the company opened an office in Singapore. In 1995, the company decided to concentrate on the North Sea.
In 2013, the company became a public company via an initial public offering on the Oslo Stock Exchange.
In 2017, the company sold its 37% interest in Robotic Drilling Systems, which it acquired in 2014.
In 2018, the company announced plans to expand its rig count from 4 to 6 to 10.
In 2018, the company acquired a drilling rig from Samsung.
See also
List of oilfield service companies
References
External links
Drilling rig operators
Engineering companies of Norway
Service companies of Norway
Offshore engineering
Petroleum industry in Norway
Companies based in Bergen
Technology companies established in 1973
Companies listed on the Oslo Stock Exchange
Norwegian companies established in 1973 | Odfjell Drilling | Engineering | 341 |
873,929 | https://en.wikipedia.org/wiki/Arabic%20numeral%20variations | There are various stylistic and typographic variations to the Arabic numeral system.
Old-style numerals
The numerals used by Western countries have two forms: lining ("in-line" or "full-height") figures as seen on a typewriter and taught in North America, and old-style figures, in which numerals 0, 1 and 2 are at x-height; numerals 6 and 8 have bowls within x-height, and ascenders; numerals 3, 5, 7 and 9 have descenders from x-height; and the numeral 4 rests along the baseline. Lining figures are generally designed all the same setting width, as this makes the printing of mathematical and trigonometrical tables simpler to do and clearer to read. Non-lining figures tend to be preferred where numbers occur within sentences, for instance when a date is given in figures in a line of text.
British presses have been partial to "old-style" numerals, even though typewriters cannot print them and they are not assigned separate Unicode values. The old-style numeral one can resemble a capital "I" reduced to x-height, and this can lead to confusion e.g. of the number 11 (when written in old-style digits) with the Roman numeral II (meaning the number two). On the other hand, with some sans serif faces, using lining figures, there can be confusion between the figure 1, lower case l (L) and upper case I (I).
Slashed zero
A distinction exists between the Danish/Norwegian letter "Ø," the Latin letter "O," and the numeral "0".
Handwritten data to be typed into a computer necessitates having a distinction between the letter "O" and numeral "0". In English-speaking countries, zero was often slashed in technical writing, and was used in many computer keyboards, screens and printing methods. Some early computerized systems for managers assumed that the numeral would be entered more often than the letter, so they slashed the letter instead. In time this became a minority practice, and it is very confusing for Danish and Norwegian speaking people.
There are three ways of ticking the numeral zero to make it distinct from the letters O and Ø. A tick in the upper right corner derives from the earlier practice, a tick in the upper left corner is used to prevent confusion with all earlier practices, and the very-low-resolution typeface "Fixedsys" has an internal tick, that does not extend beyond the bowl, in both the upper right and lower left. This is the most elegant, but it would take quite a flourish to write it on hundreds of inventory tags. Scandinavian countries prefer a numeral zero with a dot in the middle, although low-resolution displays can confuse this with a numeral eight, and it takes longer to assuredly make a dot with a ballpoint pen than making a tick.
Other variations
The "Crossed Seven" is commonly used throughout Continental Europe, but, outside of mathematics, is only sporadically used in the British Isles or the United States, and it is not permitted to be written on some inventory tags that are optically read by computers.
There are two forms of the numeral one used in France, as seen on Citroën cowls:
numeral one with a long initial stroke and an underserif; and
numeral one with a long initial stroke that starts below the underserif and is concave upward.
Central Europe uses a 'one' that has two half-serifs so it looks somewhat like a 'Z'. The region further uses a numeral four that looks like a lightning bolt, and in some areas of Eastern Europe, as seen on Romanian tanks, there is a numeral four that does not have a closed loop, but has a Greek cross form of strokes. Usually the numeral two is not slashed, whereas the letter Z is, because the handwritten form could be confused with the numeral two.
See also
Regional handwriting variation#Arabic numerals
References
External links
Alternate figures
Numerals
Typography | Arabic numeral variations | Mathematics | 849 |
2,887,043 | https://en.wikipedia.org/wiki/Plumb%20bob | A plumb bob, plumb bob level, or plummet, is a weight, usually with a pointed tip on the bottom, suspended from a string and used as a vertical direction as a reference line, or plumb-line. It is a precursor to the spirit level and used to establish a vertical datum. It is typically made of stone, wood, or lead, but can also be made of other metals. If it is used for decoration, it may be made of bone or ivory.
The instrument has been used since at least the time of ancient Egypt to ensure that constructions are "plumb", or vertical. It is also used in surveying, to establish the nadir (opposite of zenith) with respect to gravity of a point in space. It is used with a variety of instruments (including levels, theodolites, and steel tapes) to set the instrument exactly over a fixed survey marker or to transcribe positions onto the ground for placing a marker.
Etymology
The plumb in plumb bob derives from Latin plumbum ('lead'), the material once used for the weighted bob at the end. The adjective plumb developed by extension, as did the noun aplomb, from the notion of "standing upright".
Use
Until the modern age, plumb bobs were used on most tall structures to provide vertical datum lines for the building measurements. A section of the scaffolding would hold a plumb line, which was centered over a datum mark on the floor. As the building proceeded upward, the plumb line would also be taken higher, still centered on the datum. Many cathedral spires, domes and towers still have brass datum marks inlaid into their floors, which signify the center of the structure above.
A plumb bob and line alone can determine only a vertical reference. However, if they are mounted on a suitable scale the instrument may also be used as an inclinometer to measure angles to the vertical.
Ancient Egyptians used a plumb line attached to the top outer part of a tool resembling a letter E; when placed against a wall, the plumb line would indicate a vertical line. An A-frame level with a plumb line hung from the vertex was also used to find horizontal; these were used in Europe until the mid–19th century. A variation of this tool has the plumb line hung from the top of an inverted T shape.
The early skyscrapers used heavy plumb bobs, hung on wire in their elevator shafts.
A plumb bob may be in a container of water (when conditions are above freezing temperatures), molasses, very viscous oils or other liquids to dampen any swinging movement, functioning as a shock absorber.
Determining center of gravity of an irregular shape
Students of figure drawing will also make use of a plumb line to find the vertical axis through the center of gravity of their subject and lay it down on paper as a point of reference. The device used may be purpose-made plumb lines, or simply makeshift devices made from a piece of string and a weighted object, such as a metal washer. This plumb line is important for lining up anatomical geometries and visualizing the subject's center of balance.
See also
Vertical position
References
External links
60 oz. Plumb Bob.
String Line and Plumb Bob.
Inclinometers
Measuring instruments
Surveying instruments
Woodworking measuring instruments
Orientation (geometry)
Carpentry tools
Stonemasonry tools
Weights | Plumb bob | Physics,Mathematics,Technology,Engineering | 712 |
21,850 | https://en.wikipedia.org/wiki/GNU%20nano | GNU nano is a text editor for Unix-like computing systems or operating environments using a command line interface. It emulates the Pico text editor, part of the Pine email client, and also provides additional functionality. Unlike Pico, nano is licensed under the GNU General Public License (GPL). Released as free software by Chris Allegretta in 1999, nano became part of the GNU Project in 2001. The logo resembles the lowercase form of the Greek letter Eta (η).
History
GNU nano was first created in 1999 with the name TIP (a recursive acronym for TIP Isn't Pico), by Chris Allegretta. His motivation was to create a free software replacement for Pico, which was not distributed under a free-software license. The name was changed to nano on January 10, 2000, to avoid a naming conflict with the existing Unix utility tip. The name comes from the system of SI prefixes, in which nano is 1000 times larger than pico. In February 2001, nano became a part of the GNU Project.
GNU nano implements several features that Pico lacks, including syntax highlighting, line numbers, regular expression search and replace, line-by-line scrolling, multiple buffers, indenting groups of lines, rebindable key support, and the undoing and redoing of edit changes.
On 11 August 2003, Chris Allegretta officially handed the source code maintenance of nano to David Lawrence Ramsey. On 20 December 2007, with the release of 2.0.7, Ramsey stepped down as nano's maintainer. The license was also upgraded to GPL-3.0-or-later. The project is currently maintained by Benno Schulenberg.
On version 2.6.0 in June 2016, the current principal developer and the other active members of the nano project decided in consensus to leave the GNU Project, because of their objections over the Free Software Foundation's copyright assignment policy, and their belief that decentralized copyright ownership does not impede the ability to enforce the GNU General Public License. The step was acknowledged by Debian and Arch Linux, while the GNU Project resisted the move and called it a "fork". On 19 August 2016, Chris Allegretta announced the return of the project to the GNU family, following concessions from GNU on copyright assignment for Nano specifically, which happened when version 2.7.0 was released in September 2016.
Control keys
GNU nano, like Pico, is keyboard-oriented, controlled with control keys. For example, saves the current file; goes to the search menu. GNU nano puts a two-line "shortcut bar" at the bottom of the screen, listing many of the commands available in the current context. For a complete list, gets the help screen.
Unlike Pico, nano uses meta keys to toggle its behavior. For example, toggles smooth scrolling mode on and off. Almost all features that can be selected from the command line can be dynamically toggled. On keyboards without the meta key it is often mapped to the escape key, , such that in order to simulate, say, one has to press the key, then release it, and then press the key.
GNU nano can also use pointing devices, such as a mouse, to activate functions that are on the shortcut bar, as well as position the cursor.
See also
Comparison of text editors
List of text editors
List of POSIX commands
Pico (text editor)
Notes
References
External links
Command-line software
1999 software
Console applications
Cross-platform software
Free and open-source software
Free software programmed in C
Free text editors
Nano
Linux text editors
MacOS text editors
Free software that uses ncurses
Unix text editors
Software using the GNU General Public License | GNU nano | Technology | 768 |
72,293,009 | https://en.wikipedia.org/wiki/O-Octadecylhydroxylamine | O-Octadecylhydroxylamine (ODHA) is a white solid organic compound with the formula . ODHA is a noncanonical lipid, which contains a saturated alkyl tail and an aminooxy headgroup. This noncanonical lipid can be site selectively appended to the N-terminal of desired biopolymers such as peptides. ODHA drives the supramolecular assembly of modified protein, presumably through the hydrophobic collapse of ODHA chains.
Preparation
ODHA is prepared from the reaction between 2-(octadecyloxy)isoindoline-1,3-dione and hydrazine hydrate.
Reaction
ODHA modification
A pH-responsive oxime bond is used to install an ODHA-type synthetic lipid (octadecylhydroxylamine) in place of the N terminal serine residue in N-myristoylation PTM. N-terminal myristoylation is a post-translational modification carried out by the enzyme N-myristoyltransferase. Generally, the 12-carbon myristoyl lipid is added to the N-terminus of proteins. The lipid is attached to the protein via a stable amide bond. However, the ODHA lipid is attached to the protein via an oxime bond, due to the structure of the non-canonical lipid. The reaction is chemical, compared to the enzymatic NMT reaction. Self-assembly is driven by the hydrophobic nature of the attached lipid, and disassembly is controlled by oxime degradation in an acidic environment. The reaction between the lipid and oxidized protein is biomolecular, which means it is following second order rate kinetics since it is dependent on oxidized protein (ELP) and lipids (ODHA).
References
Lipids
Hydroxylamines | O-Octadecylhydroxylamine | Chemistry | 395 |
2,749,927 | https://en.wikipedia.org/wiki/Eta%20Volantis | Eta Volantis, Latinized from η Volantis, is a single star in the southern constellation of Volans. It has an apparent visual magnitude of 5.28, which is bright enough to be seen with the naked eye as a dim, white-hued star. Based upon parallax measurements, it is approximately 387 light years from the Sun. The star is moving further away from the Sun with a radial velocity of .
This is an A-type star with a stellar classification of A0/1 IV/V, displaying blended spectrum that shows aspects of a main sequence star and a subgiant. Stellar evolution models from Zorec and Royer (2012) place it near the main sequence turnoff, having completed 90.7% of its time on the main sequence. The star is estimated to be 347 million years old and is spinning rapidly with a projected rotational velocity of 214 km/s. It has 2.73 times the mass of the Sun and 3.43 times the Sun's radius. Eta Volantis is radiating 84 times the luminosity of the Sun from its photosphere at an effective temperature of .
Eta Volantis has two 12th magnitude optical companions at angular separations of 26.8 and 48.1 arcseconds.
References
A-type main-sequence stars
A-type subgiants
Volans
Volantis, Eta
Durchmusterung objects
071576
041003
3334 | Eta Volantis | Astronomy | 302 |
1,630,512 | https://en.wikipedia.org/wiki/Rear-view%20mirror | A rear-view mirror (or rearview mirror) is a, usually flat, mirror in automobiles and other vehicles, designed to allow the driver to see rearward through the vehicle's rear window (rear windshield).
In cars, the rear-view mirror is usually affixed to the top of the windshield on a double-swivel mount allowing it to be adjusted to suit the height and viewing angle of any driver and to swing harmlessly out of the way if impacted by a vehicle occupant in a collision.
The rear-view mirror is augmented by one or more side-view mirrors, which serve as the only rear-vision mirrors on trucks, motorcycles and bicycles.
History
Early use of fixed mirrors was described as early as 1906, with a trade magazine noting mirrors for showing what is coming behind were now popular on closed bodied automobiles, and were likely to be widely adopted in a short time. The same year, a Mr. Bilal Ghanty from France patented a "Warning mirror for automobiles". The Argus Dash Mirror, adjustable to any position to see the road behind, appeared in 1908. Earliest known rear-view mirror mounted on a racing vehicle appeared on Ray Harroun's Marmon race car at the inaugural Indianapolis 500 race in 1911. Harroun himself claimed he got the idea from seeing a mirror used for a similar purpose on a horse-drawn vehicle in 1904. Harroun also claimed that the mirror vibrated constantly due to the rough brick surface, and it was rendered largely useless.
Elmer Berger is usually credited with inventing the rear-view mirror, though in fact he was the first to patent it (1921) and develop it for incorporation into production street going automobiles by his Berger and Company.
Augmentations and alternatives
Recently, rear-view video cameras have been built into many new model cars, this was partially in response to the rear-view mirrors' inability to show the road directly behind the car, due to the rear deck or trunk obscuring as much as 3–5 meters (10–15 feet) of road behind the car. As many as 50 small children are killed by SUVs every year in the USA because the driver cannot see them in their rear-view mirrors. Camera systems are usually mounted to the rear bumper or lower parts of the car, allowing for better rear visibility.
Aftermarket secondary rear-view mirrors are available. They attach to the main rear-view mirror and are independently adjustable to view the back seat. This is useful to enable adults to monitor children in the back seat.
Anti-glare
A prismatic rear-view mirror—sometimes called a "day/night mirror"—can be tilted to reduce the brightness and glare of lights, mostly for high-beam headlights of vehicles behind which would otherwise be reflected directly into the driver's eyes at night. This type of mirror is made of a piece of glass that is wedge-shaped in cross-section—its front and rear surfaces are not parallel.
On manual tilt versions, a tab is used to adjust the mirror between "day" and "night" positions. In the day view position, the front surface is tilted and the reflective back side gives a strong reflection. When the mirror is moved to the night view position, its reflecting rear surface is tilted out of line with the driver's view. This view is actually a reflection of the low-reflection front surface; only a much-reduced amount of light is reflected in the driver's eyes.
"Manual tilt" day/night mirrors first began appearing in the 1930s and became standard equipment on most passenger cars and trucks by the early 1970s.
Automatic dimming
In the 1940s, American inventor Jacob Rabinow developed a light-sensitive automatic mechanism for the wedge-type day/night mirror. Several Chrysler Corporation cars offered these automatic mirrors as optional equipment as early as 1959, but few customers ordered them for their cars and the item was soon withdrawn from the option lists. Several automakers began offering rear-view mirrors with automatic dimming again in 1983, and it was in the late 1980s that they began to catch on in popularity.
Current systems usually use photosensors mounted in the rear-view mirror to detect light and dim the mirror by means of electrochromism. This electrochromic feature has also been incorporated into side-view mirrors allowing them to dim and reduce glare as well.
Suspending objects
Objects are sometimes hung from the rear-view mirror, including cross necklaces, prayer beads, good luck charms, decorations like fuzzy dice, and air fresheners like Little Trees. In some jurisdictions such hanging is illegal on the basis that it impairs the driver's forward view and so compromises safety. Black Lives Matter protesters have cited this as an example of the minor violations used as grounds for traffic stops disproportionately targeting black drivers.
Trucks and buses
On trucks and buses, the load often blocks rearward vision out the backlight. In the U.S. virtually all trucks and buses have a side view mirror on each side, often mounted on the doors and viewed out the side windows, which are used for rear vision. These mirrors leave a large unviewable ("blind") area behind the vehicle, which tapers down as the distance increases. This is a safety issue which the driver must compensate for, often with a person guiding the truck back in congested areas, or by backing in a curve. "Spot mirrors", a convex mirror which provides a distorted image of the entire side of the vehicle, are commonly mounted on at least the right side of a vehicle. In the U.S. mirrors are considered "safety equipment", and are not included in width restrictions.
Motorcycles
Depending on the type of motorcycle, the motorcycle may or may not have rear-view mirrors. Street-legal motorcycles are generally required to have rear-view mirrors. Motorcycles for off-road use only normally do not have rear-view mirrors. Rear-view mirrors come in various shapes and designs and have various methods of mounting the mirrors to the motorcycle, most commonly to the handlebars. Rear-view mirrors can also be attached to the rider's motorcycle helmet. The Reevu MSX1 helmet uses an internal periscope that allows the user rear vision.
Bicycles
Some bicycles are equipped with a rear-view mirror mounted on a handlebar. Rear-view mirrors may also be fitted to the bicycle frame, on a helmet, on the arm or the frame of a pair of eyeglasses. This allows what is behind to be checked continuously without turning round. Rear-view mirrors almost never come with a new bicycle and require an additional purchase.
Aircraft
By 1956, the Civil Aeronautics Administration had approved a rear-view mirror for light aircraft. They also predicted periscopes in larger aircraft. Fighter aircraft usually have one or more rear-view mirrors mounted on the front canopy frame to watch out for chasing aircraft.
See also
Automatic parking
Backup collision
Backup camera
Blind spot monitor
Blind spot (vehicle)
Dashcam
Intelligent Parking Assist System
Experimental Safety Vehicle (ESV)
Intelligent car
Lane departure warning system
List of auto parts
Precrash system
Wing mirror
References
1911 introductions
Mirrors
Vehicle parts | Rear-view mirror | Technology | 1,461 |
73,734,121 | https://en.wikipedia.org/wiki/Nek5000 | Nek5000 is a highly scalable spectral element computational fluid dynamics code for solving the incompressible Navier-Stokes equations on 2D quadrilateral and 3D hexahedral meshes. Nek5000 was awarded the 1999 Gordon Bell Prize and a 2016 R&D 100 Award.
History
Related and derived codes
Gslib
Nekbone
Neko
NekCEM
NekLBM
NekROM
NekRS
ParRSB
References
Computational fluid dynamics
Free science software
Free computer-aided design software
Scientific simulation software | Nek5000 | Physics,Chemistry | 108 |
49,344,896 | https://en.wikipedia.org/wiki/Oxosilanol | Oxosilanol is a chemical compound. It is the silicon-analogue to formic acid, with silicon replacing carbon.
References
Silanols | Oxosilanol | Chemistry | 31 |
3,193,208 | https://en.wikipedia.org/wiki/Sense%20Plan%20Act | Sense-Plan-Act was the predominant robot control methodology through 1985.
Sense - gather information using the sensors
Plan - create a world model using all the information, and plan the next move
Act
SPA is used in iterations: After the acting phase, the sensing phase, and the entire cycle, is repeated.
see also: OODA loop, PDCA, Continual improvement process
References
Robot architectures | Sense Plan Act | Engineering | 81 |
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