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61,129,384 | https://en.wikipedia.org/wiki/Sheila%20Essey%20Award | The Sheila Essey Award for ALS Research was established in 1996 and is sponsored by the American Academy of Neurology. The prize is funded through the philanthropy of the Essey family and the ALS Association. The award recognizes an individual who has made seminal research contributions in the search for the cause, prevention of, and cure for amyotrophic lateral sclerosis.
The award includes a trophy, a $50,000 prize, and a 20-minute lecture at the American Academy of Neurology annual meeting. The prize is named after Sheila Essey (wife of Richard Essey) who was diagnosed with amyotrophic lateral sclerosis in 1994.
Awardees
Source: American Academy of Neurology
1996 Robert H. Brown Jr.
1996 Teepue Siddique
1997 Jeffrey Rothstein
1998 Theodore Munsat
1998 Lewis P. Rowland
1999 Don Cleveland
2000 Jean Pierre Julien
2001 Pamela Shaw
2002 Serge Przedborski
2003 Stanley Appel
2004 Peter Nigel Leigh
2005 Michael Strong
2006 Peter Carmeliet
2007 Christopher Henderson
2008 Wim Robberecht
2009 Merit Cudkowicz
2009 Orla Hardiman
2010 Clive Svendsen, PhD
2011 Leonard van den Berg
2012 Christopher Shaw, MD, FRACP
2013 Rosa Rademakers
2013 Bryan J. Traynor
2014 Jeremy Shefner
2015 Robert Bowser, PhD
2015 Adriano Chiò
2016 Ammar Al-Chalabi
2017 John M. Ravits
2018 Timothy Miller
2019 Aaron Gitler
See also
List of medicine awards
References
Awards established in 1996
Medicine awards
American science and technology awards
Neuroscience awards
1996 establishments in the United States | Sheila Essey Award | [
"Technology"
] | 320 | [
"Science and technology awards",
"Medicine awards",
"Neuroscience awards"
] |
61,130,095 | https://en.wikipedia.org/wiki/Dust%20defense | Dust defense, sometimes called environmental defense, was a proposed anti-ballistic missile (ABM) system considered for protecting both Minuteman and MX Peacekeeper missile silos from Soviet attack.
Operation
The system works by burying a number of high-yield warheads near the missile field below the anticipated flight corridor of approaching enemy reentry vehicles (warheads). Approximately five to ten minutes before the arrival of the enemy warheads, the dust defense warheads would be detonated, sending a cloud of dust high into the atmosphere. Enemy RVs would strike this cloud of dust at approximately which would rapidly abrade the RV's heat shield causing the warhead to fail due to reentry heating or for the warhead to be knocked off course.
The effectiveness of the system depended on the hardness of enemy RVs to abrasion and the yield of the weapon used. Approximately of dust would be produced per megaton of warhead yield. While it's possible that an RV could be hardened against the effects of this dust, doing so would carry a steep penalty in RV weight.
Advantages and disadvantages of the system
The advantage of the system compared to more conventional interceptor based ABM systems is that dust defense provides a "screen" thatwhile activeprovides protection regardless of decoys and the number of warheads used.
Dust defense also has the advantage of being an "unambiguous" defense, in that the system is only seen as suitable for defending hard targets such as ICBM silos and therefore it only protects retaliatory capability. By only protecting retaliatory capability the system is thought to help preserve the balance of mutually assured destruction instead of degrading this balance as an ABM system protecting population centers would. Ignoring the issues of detonating a dust defense warhead near population centers, dust defense only provides protection for thirty minutes to an hour; long enough to allow for ICBMs to launch, but once the dust cloud settles the city remains to be retargeted.
One of the issues with the system is that of a false alarm. Due to fallout and the consequences of detonating a nuclear weapon on your own soil, the consequences of a false alarm are much more severe than in found in interceptor based ABM. However, during a false alarm if a nation is forced to use launch on warning to prevent the destruction of their ICBM force on the ground, a nation would receive massive casualties from the enemy's retaliatory attack. Therefore, a dust defense system to prevent the need for launch on warning would be safer as in a false alarm you have only slightly irradiated some of your nation instead of facing the full brunt of a retaliatory attack.
Dust defenselike any other ground burst nuclear detonationwould produce fallout. However, the stationary nature of the system means that weight and size is not an issue, so very low fission fraction technologies developed for Project Plowshare could be used to reduce the effects of fallout. One source alleges that fission fractions of less than 2% in a weapon would be possible. This would be less than a percent of the fission produced by Soviet warheads the system stops. Another source claims that by assembling the weapons inside underground vaults and then surrounding the weapons with borated water (which readily absorbs neutrons), fission fractions could be reduced to 1% of that of a conventional fission fraction weapon.
Variations
A variation of dust defense was proposed to instead time detonation to several seconds before the RVs detonated. Instead of destroying enemy RVs through dust, this would destroy RVs through the impact (instead of abrasion) of material thrown up by the blast. This proposal was believed to have a greater chance of success than the abrasion concept (which was thought to require testing and had uncertainties) while also providing a cloud of abrasive dust that could also destroy RVs. This system was proposed to defend Dense Pack.
Dense pack itself was based on the dust defense concept, except in its basic form the dust was created by Soviet warheads attacking dense pack.
See also
Ash CarterAuthor of Ballistic Missile Defense and later US Secretary of Defense.
References
Nuclear warfare | Dust defense | [
"Chemistry"
] | 858 | [
"Radioactivity",
"Nuclear warfare"
] |
61,131,263 | https://en.wikipedia.org/wiki/CTL%20Corporation | CTL Corporation is an Oregon-based computer manufacturer that produces Chromebooks and Chromeboxes.
Company
CTL was founded as Computer Technology Link Corp in 1989 and is based in Beaverton, Oregon. In 2015 it opened offices in Vigo, Spain as well. The chief executive officer is Erik Stromquist.
Computers
In 1999, CTL began providing computers and technical support to the government of Malaysia and its education system. CTL began manufacturing all-in-one PCs again in the early 2010s. In 2014 CTL partnered with CryptoRig in order to produce currency-mining computer systems. In 2016 CTL Chromebooks were provided to teachers and students in Nevada education system via a legislative appropriation of $20 million passed through the Nevada State House.
In 2018 CTL partnered with Google and Sprint in order to develop a Chromebook with access to LTE mobile service, creating the Chromebook NL7 LTE. It also released the Core i7 version. In 2019 the company released the CTL Chromebook Tab Tx1, with two Cortex-A72 cores and four further Cortex-A53, and 4 GB of memory and 32 GB of storage. That year CTL also released the Chromebox CBx1-7 for mounting to visual displays.
See also
References
1989 establishments in Oregon
Computer companies of the United States
Companies based in Beaverton, Oregon
Computer hardware companies
Computer systems companies | CTL Corporation | [
"Technology"
] | 283 | [
"Computer hardware companies",
"Computer systems companies",
"Computers",
"Computer systems"
] |
61,132,898 | https://en.wikipedia.org/wiki/Mamanteo | A mamanteo or amuna is a pre-Columbian water harvesting system used in mountainous parts of Peru.
It works by 'delaying' rainy-season runoff in the mountains so it can be used in lowlands settlements during the dry season. Using canals, the system targets floods to permeable sections of soil or rock. The water is filtered by the ground layers and emerges in downslope springs weeks or months later, where it can be used to mitigate drought.
The technology may have been used by the Andean Wari culture as early as 700 AD, and some of the ancient systems have been restored in the 21st century to serve modern cities.
Modern restoration work
Lima is the world's second-largest desert city, behind Cairo, and served by a much smaller river than Cairo. To meet the needs of a 'desert city which keeps growing', Sunass, the Peruvian national water agency, intends to '[combine] grey infrastructure with green infrastructure' and has created a tax-supported PES fund; some of this money has gone to regrouting mamanteos. As of 2016, ten mamanteos had been restored.
A study of the system in Huamantanga, Peru modeled an expansion to serve modern Lima, claiming it could extend the growing season for local farms. The study authors measured the amount of water stored and the time taken to deliver the water downslope, and proposed an extrapolation model to estimate large-scale effects of up-scaling the system.
A climate risk study by Peruvian hydrology agencies includes the restoration of amunas on its shortlist of adaptive practices that have 'low cost and high hydrological benefit', along with management of grasslands, restoration of wetlands and forests, and other hydrological engineering projects.
External links
Ancestral technology, cheese and water for Lima, weadapt.org
Ancient intervention could boost dwindling water reserves in coastal Peru, phys.org
Ancient Peruvian engineering could help solve modern water shortages, Ars Technica
Seeking relief from dry spells, Peru’s capital looks to its ancient past, National Geographic
Amunas, Siembra de Agua, Cusqueña
See also
Qanat—an ancient Persian irrigation system for bringing wellwater downslope
References
Pre-Columbian cultures
Water wells
Irrigation
Water supply
Ancient technology | Mamanteo | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 466 | [
"Hydrology",
"Water wells",
"Water supply",
"Environmental engineering"
] |
61,138,636 | https://en.wikipedia.org/wiki/Jordans%27%20anomaly | Jordans' anomaly (also known as Jordan anomaly and Jordans bodies) is a familial abnormality of white blood cell morphology. Individuals with this condition exhibit persistent vacuolation of granulocytes and monocytes in the peripheral blood and bone marrow. Jordans' anomaly is associated with neutral lipid storage diseases.
Genetics
Jordans' anomaly is a characteristic finding in Chanarin-Dorfman syndrome and other neutral lipid storage diseases. The anomaly is associated with mutations in the PNPLA2 gene, which produces the enzyme adipose triglyceride lipase (ATGL), and the ABHD5 gene, which encodes a cofactor of ATGL. These mutations lead to defective triglyceride breakdown and accumulation of lipid droplets in cells throughout the body.
Histopathology
The vacuoles of Jordans' anomaly contain neutral lipids that stain positive with Sudan staining techniques.
History
The anomaly was first described in 1953, by Dr. G. H. Jordans, who identified abnormal vacuolation in the white blood cells of two brothers with congenital muscular dystrophy. Using special staining, Jordans demonstrated that the vacuoles contained lipids. In 1966, two further cases of persistent lipid vacuoles were reported in sisters presenting with ichthyosis. The Chanarin-Dorfman syndrome, comprising Jordans' anomaly, ichthyosis and lipid storage abnormalities, was defined in the 1970s, definitively connecting Jordans' anomaly to lipid storage disease. Jordans' anomaly was linked to genetic mutations affecting triglyceride metabolism in 2006.
References
Hematology
Hematopathology
Histopathology
Abnormal clinical and laboratory findings for blood
Lipid storage disorders | Jordans' anomaly | [
"Chemistry"
] | 359 | [
"Histopathology",
"Microscopy"
] |
61,139,017 | https://en.wikipedia.org/wiki/Estradiol%20benzoate/progesterone/methandriol%20dipropionate | Estradiol benzoate/progesterone/methandriol dipropionate (EB/P4/MADP), sold under the brand name Progestandron (Organon), is an injectable combination medication of estradiol benzoate (EB), an estrogen, progesterone (P4), a progestogen, and methandriol dipropionate (MADP), an androgen/anabolic steroid. It contained 3 mg EB, 20 mg P4, and 50 mg MADP, was provided in the form of ampoules, and was administered by intramuscular injection. The medication was marketed by 1957. It is no longer available.
See also
List of combined sex-hormonal preparations § Estrogens, progestogens, and androgens
References
Abandoned drugs
Combined estrogen–progestogen–androgen formulations | Estradiol benzoate/progesterone/methandriol dipropionate | [
"Chemistry"
] | 199 | [
"Drug safety",
"Abandoned drugs"
] |
61,141,504 | https://en.wikipedia.org/wiki/C22H30N2O2 | {{DISPLAYTITLE:C22H30N2O2}}
The molecular formula C22H30N2O2 (molar mass: 354.485 g/mol) may refer to:
A-796,260
Eprozinol
Martinostat
Molecular formulas | C22H30N2O2 | [
"Physics",
"Chemistry"
] | 62 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,141,699 | https://en.wikipedia.org/wiki/FARME | FARME also known as Functional Antibiotic Resistance Metagenomic Element is a database that compiles publicly available DNA elements and predicted proteins that confer antibiotic resistance, regulatory elements and mobile genetic elements. It is the first database to focus on functional metagenomics. This allows the database to understand 99% of bacteria which cannot be cultured, the relationship between environmental antibiotic resistance sequences and antibiotic genes derived from cultured isolates. This information was derived from 20 metagenomics projects from GenBank. Also from GenBank are the protein sequence predictions and annotations.
See also
Antimicrobial Resistance databases
References
Metagenomics
Biological databases
Antimicrobial resistance organizations | FARME | [
"Biology"
] | 139 | [
"Bioinformatics",
"Biological databases"
] |
61,142,179 | https://en.wikipedia.org/wiki/C18H18N2O | {{DISPLAYTITLE:C18H18N2O}}
The molecular formula C18H18N2O (molar mass: 278.348 g/mol) may refer to:
AC-262,536
Demexiptiline
Mariptiline
Proquazone
Molecular formulas | C18H18N2O | [
"Physics",
"Chemistry"
] | 65 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,143,497 | https://en.wikipedia.org/wiki/C22H25NO5 | {{DISPLAYTITLE:C22H25NO5}}
The molecular formula C22H25NO5 (molar mass: 383.437 g/mol, exact mass: 383.1733 u) may refer to:
Acetylpropionylmorphine
Sacubitrilat
Molecular formulas | C22H25NO5 | [
"Physics",
"Chemistry"
] | 69 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,143,617 | https://en.wikipedia.org/wiki/Anton%20Sushkevich | Anton Kazimirovich Sushkevich (Антон Казимирович Сушкевич) (23 January 1889, Borisoglebsk, Russia — 30 August 1961, Kharkiv, Ukraine) was a Russian mathematician and textbook author who expanded group theory to include semigroups and other magmas.
Sushkevich attended secondary school in Voronezh and studied in Berlin from 1906 to 1911. There he attended lectures of F. G. Frobenius, Issai Schur, and Hermann Schwarz. Sushkevich studied piano with L. V. Rostropovich, father of Mstislav Rostropovich. In 1906 he was a cello student at Stern Conservatory (now part of Berlin University of the Arts). In 1911 he moved to Saint Petersburg, graduating from the Imperial University in 1913.
Moving to Kharkiv, Suskevich taught in secondary education while he pursued a graduate degree at Kharkov State University. His dissertation was The theory of operations as the general theory of groups. Obtaining the degree, he became an assistant professor at the university in 1918, and adjunct professor in 1920.
Voronezh State University employed Sushkevich in 1921 as professor of mathematics. He published the first edition of his Higher Algebra (1923). He published a generalization of Cayley's theorem for certain finite semigroups in 1926. The next year he was in Moscow for the Russian Mathematical Congress, and the following year in Bologna for the International Congress of Mathematicians.
In Kharkiv, the Ukrainian Scientific Research Institute of Mathematics and Mechanics was established in 1929 with Sushkevich as a member. With a rising interest in abstract algebra, he wrote a second book on algebra: Foundations of Higher Algebra which was published both in Russian and Ukrainian. In 1933 he directed the Algebra & Number Theory section of Kharkov State University's department of mathematics. At that time Stalin caused a famine in Ukraine, the Holodomor, killing millions especially in rural areas. Suskevich survived to edit new editions of his textbook that included "new algebra": fields, integral domains, rings, ideals, and quaternions. His original work, The Theory of Generalized Groups (1937) opened up the area of semigroups. According to biographer Hollings, "He sought to describe his semigroups of interest in terms of certain of their subgroups: from Sushkevich's point of view, groups were objects of known structure."
Selected works
1928: .
1929: "On a generalization of the associative law", Transactions of the American Mathematical Society 31(1):204–14
1951: "Materials for the History of Algebra in Russia in the 19th and beginning of the 20th centuries",
1954: Theory of Numbers, second edition 1956
References
Christopher Hollings (2009) "The early development of the algebraic theory of semigroups", Archive for History of Exact Sciences 63(5): 497–536, especially 511–513.
Christopher Hollings Summary of "Finite groups without unique invertibiility" (PDF) via WebCite
20th-century Russian mathematicians
Russian textbook writers
Algebraists
Soviet textbook writers
Soviet male writers
Soviet mathematicians
20th-century Russian male writers | Anton Sushkevich | [
"Mathematics"
] | 681 | [
"Algebra",
"Algebraists"
] |
61,143,705 | https://en.wikipedia.org/wiki/C20H12N2Na2O7S2 | {{DISPLAYTITLE:C20H12N2Na2O7S2}}
The molecular formula C20H12N2Na2O7S2 (molar mass: 502.42 g/mol, exact mass: 501.9881 u) may refer to:
Acid_Red_13
Azorubine
Ponceau 6R | C20H12N2Na2O7S2 | [
"Chemistry"
] | 78 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,144,035 | https://en.wikipedia.org/wiki/C6428H9912N1694O1987S46 | {{DISPLAYTITLE:C6428H9912N1694O1987S46}}
The molecular formula C6428H9912N1694O1987S46 (molar mass: 144190.3 g/mol) may refer to:
Adalimumab
Infliximab | C6428H9912N1694O1987S46 | [
"Chemistry"
] | 75 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,144,542 | https://en.wikipedia.org/wiki/Siegel%20modular%20variety | In mathematics, a Siegel modular variety or Siegel moduli space is an algebraic variety that parametrizes certain types of abelian varieties of a fixed dimension. More precisely, Siegel modular varieties are the moduli spaces of principally polarized abelian varieties of a fixed dimension. They are named after Carl Ludwig Siegel, the 20th-century German number theorist who introduced the varieties in 1943.
Siegel modular varieties are the most basic examples of Shimura varieties. Siegel modular varieties generalize moduli spaces of elliptic curves to higher dimensions and play a central role in the theory of Siegel modular forms, which generalize classical modular forms to higher dimensions. They also have applications to black hole entropy and conformal field theory.
Construction
The Siegel modular variety Ag, which parametrize principally polarized abelian varieties of dimension g, can be constructed as the complex analytic spaces constructed as the quotient of the Siegel upper half-space of degree g by the action of a symplectic group. Complex analytic spaces have naturally associated algebraic varieties by Serre's GAGA.
The Siegel modular variety Ag(n), which parametrize principally polarized abelian varieties of dimension g with a level n-structure, arises as the quotient of the Siegel upper half-space by the action of the principal congruence subgroup of level n of a symplectic group.
A Siegel modular variety may also be constructed as a Shimura variety defined by the Shimura datum associated to a symplectic vector space.
Properties
The Siegel modular variety Ag has dimension g(g + 1)/2. Furthermore, it was shown by Yung-Sheng Tai, Eberhard Freitag, and David Mumford that Ag is of general type when g ≥ 7.
Siegel modular varieties can be compactified to obtain projective varieties. In particular, a compactification of A2(2) is birationally equivalent to the Segre cubic which is in fact rational. Similarly, a compactification of A2(3) is birationally equivalent to the Burkhardt quartic which is also rational. Another Siegel modular variety, denoted A1,3(2), has a compactification that is birationally equivalent to the Barth–Nieto quintic which is birationally equivalent to a modular Calabi–Yau manifold with Kodaira dimension zero.
Siegel modular varieties cannot be anabelian.
Applications
Siegel modular forms arise as vector-valued differential forms on Siegel modular varieties. Siegel modular varieties have been used in conformal field theory via the theory of Siegel modular forms. In string theory, the function that naturally captures the microstates of black hole entropy in the D1D5P system of supersymmetric black holes is a Siegel modular form.
In 1968, Aleksei Parshin showed that the Mordell conjecture (now known as Faltings's theorem) would hold if the Shafarevich finiteness conjecture was true by introducing Parshin's trick. In 1983 and 1984, Gerd Faltings completed the proof of the Mordell conjecture by proving the Shafarevich finiteness conjecture. The main idea of Faltings' proof is the comparison of Faltings heights and naive heights via Siegel modular varieties.
See also
Hilbert modular surface
Hilbert scheme
Jacobian variety
References
Algebraic geometry
Algebraic varieties
Moduli theory | Siegel modular variety | [
"Mathematics"
] | 675 | [
"Fields of abstract algebra",
"Algebraic geometry"
] |
61,146,406 | https://en.wikipedia.org/wiki/Log-rank%20conjecture | In theoretical computer science, the log-rank conjecture states that the deterministic communication complexity of a two-party Boolean function is polynomially related to the logarithm of the rank of its input matrix.
Let denote the deterministic communication complexity of a function, and let denote the rank of its input matrix (over the reals). Since every protocol using up to bits partitions into at most monochromatic rectangles, and each of these has rank at most 1,
The log-rank conjecture states that is also upper-bounded by a polynomial in the log-rank: for some constant ,
Lovett
proved the upper bound
This was improved by Sudakov and Tomon, who removed the logarithmic factor, showing that
This is the best currently known upper bound.
The best known lower bound, due to Göös, Pitassi and Watson, states that . In other words, there exists a sequence of functions , whose log-rank goes to infinity, such that
In 2019, an approximate version of the conjecture has been disproved.
See also
List of unsolved problems in computer science
References
Communication
Computational complexity theory
Conjectures
Unsolved problems in computer science
Information theory | Log-rank conjecture | [
"Mathematics",
"Technology",
"Engineering"
] | 248 | [
"Unsolved problems in mathematics",
"Telecommunications engineering",
"Unsolved problems in computer science",
"Applied mathematics",
"Conjectures",
"Information theory",
"Computer science",
"Mathematical problems"
] |
53,500,559 | https://en.wikipedia.org/wiki/Floristic%20diversity | Floristic diversity is variety in the genome of flowering plants, as well as variety at the species and ecosystem level. Floristic diversity covers how many varieties of plant species in a specific area there are. There are multiple factors that contribute to floristic diversity, including both biotic (living) and abiotic (not living) elements. Elements that alter floristic diversity include climate, weather, soil, and animals. Floristic diversity allows different regions to analyze the environment and the evolution of the area.
The genome of plants can be different based on size, number of chromosomes, and order of gene. Analyzing genomes in plants helps scientists to determine differences and similarities within plant species.
Etymology
In the word floristic, "flora" means "flower" in Latin. Floristic is used to describe something relating plants or flowers.
In the word diversity, the Latin root "diversus" means "various." Diversity is used to describe variety or a range of differences.
Floristic diversity in Latin America
One region in Latin America with one of the largest amount of floristic diversity in plants is the Andes Mountains Tropical Hotspot, known for being biodiverse and having one-sixth of the worlds plant species residing there. By having a wide variety in climate such as having multiple elevations, many types of ecosystems, and temperature differences, this mountain strip has the ability to host multiple types of plants.
References
External links
Floristic diversity in a model system using experimental microcosms
Biodiversity
Flowers | Floristic diversity | [
"Biology"
] | 310 | [
"Biodiversity"
] |
53,501,645 | https://en.wikipedia.org/wiki/The%20Deserter%27s%20Wife | The Deserter's Wife () is a 1991 French-Israeli co-production dramatic independent underground art film directed by Michal Bat-Adam.
Synopsis
Nina (Fanny Ardant), a French concert pianist, meets Ilan (), an Israeli computer specialist who is on vacation, in Paris. They fall in love, marry, and, move to Israel with their son, Gili (Daniele Napolitano). Not much later, Ilan is drafted into the Israeli military for compulsory military service, as the situation in the Middle East is worsening: Saddam Hussein has attacked Kuwait with his Iraqi forces and the Second Gulf War is imminent. After Nina is accepted into the Israel Philharmonic Orchestra, she receives a call from the military and learns that her husband was wounded during a battle. She hurries to him and finds out, to her horror, that Ilan was not injured by enemy troops but by Israeli soldiers when he tried to leave his post illegally. While Ilan is wounded in a hospital and is unable to speak due to a state of shock, the accusations that he is a deserter, she finds out, are true. Despite this revelation, Nina continues to take care of him, breaks off an affair with another man, and tries to understand his motives. Their environment's reaction, however, extends not only to Ilan but also to Nina. When Nina's concert debut with the Israel Philharmonic Orchestra is about to take place, symbolically, on the day of the United Nations' ultimatum to Saddam Hussein, the social pressure grows immeasurably. Nina leaves Ilan and returns to France with Gili.
Background
Actress Fanny Ardant and cinematographer got to know each other while filming Margarethe von Trotta's Love and Fear during 1988. In 1990 their daughter Baladine was born. Ardant and Conversi eventually parted. However, they worked together again and again, as with La Femme du déserteur, as well as in 2008, on the comedy Hello Goodbye, which Conversi produced, while Ardant played alongside Gérard Depardieu. La Femme du déserteur premiered on 20 December 1991 in France. Critic Lisa Alspector opined that "[t]his 1991 melodrama creates only generic sympathy for the disgraced, misunderstood husband, and none at all for the smarmy, selfish wife, whose motives are ambiguous throughout." In Israel, Al HaMishmar critic underscored that "had this film never been made, it would have needed to be invented," while Yedioth Ahronoth critic Yehuda Stav wrote that the film is "humble and sympathetic, its material taken from daily Israeli experiences," and, Davar critic Uri Shin praised the film's uncompromising refusal to placate the audience.
References
External links
La Femme du déserteur at the TCM Movie Database
1991 drama films
1991 independent films
1991 films
1991 multilingual films
Films about adultery
Films about classical music and musicians
Films about computing
Films about diseases and disorders
Films about families
Films about immigration
Films about pianos and pianists
Films about psychiatry
Films about the United Nations
Films directed by Michal Bat-Adam
Films set in concert halls
Films set in Israel
Films set in Paris
Films shot in Israel
Films shot in Paris
French drama films
French independent films
French multilingual films
1990s French-language films
1990s Hebrew-language films
Films set in hospitals
Israeli drama films
Israeli independent films
Israeli multilingual films
Films about post-traumatic stress disorder
1990s French films
French-language Israeli films | The Deserter's Wife | [
"Technology"
] | 716 | [
"Works about computing",
"Films about computing"
] |
53,502,028 | https://en.wikipedia.org/wiki/Gambierol | Gambierol is a marine polycyclic ether toxin which is produced by the dinoflagellate Gambierdiscus toxicus. Gambierol is collected from the sea at the Rangiroa Peninsula in French Polynesia. The toxins are accumulated in fish through the food chain and can therefore cause human intoxication. The symptoms of the toxicity resemble those of ciguatoxins, which are extremely potent neurotoxins that bind to voltage-sensitive sodium channels and alter their function. These ciguatoxins cause ciguatera fish poisoning. Because of the resemblance, there is a possibility that gambierol is also responsible for ciguatera fish poisoning. Because the natural source of gambierol is limited, biological studies are hampered. Therefore, chemical synthesis is required.
Structure and reactivity
Gambierol is a ladder-shaped polyether, composed of eight ether rings, 18 stereocenters, and two challenging pyranyl rings having methyl groups that are in a 1,3-diaxial orientation to one another.
Different structural analogues were synthesized to determine which groups and side chains attached to the gambierol are essential for its toxicity. Not only the fused polycyclic ether core is essential, but also the triene side chain at C51 and the C48-C49 double bond were indispensable. In the triene side chain, the double bond between C57 and C58 was essential. The C1 and C8 hydroxy groups were not essential, but they enhance the activity. The conjugate diene in the triene side chain also enhances the toxicity.
Synthesis
The synthesis of gambierol consists of two tetracyclic precursor molecules, one alcohol and one acetic acid, that fuse together. The whole synthesis of gambierol is depicted in the figure below. After obtaining the octacyclic backbone, the tail is added via Stille coupling. The acetic acid (compound 1) and alcohol (compound 2) are converted to compound 3. The reaction of compound 3 with the titanium alkylidene from dibromide 1,1-dibromoethane, provides cyclic enol ether (compound 4). Oxidation of the alcohols gives majorly compound 5, but also compound 6. These are both ketones, but they have other stereochemistry. Compound 6 can be converted back in compound 5 with reactant c, thereby moving the equilibrium towards compound 5. This ketone can be converted further to produce reactive gambierol. By reductive cyclization of the D ring, the octacyclic core structure (compound 7) was made. Oxidation of compound 7 to the aldehyde was followed by formation of the diiodolefin. Stereoselective reduction, global deprotection and Stille coupling of compound 8 with dienyl stannane (compound 9) provide gambierol.
Mechanism of action
Gambierol acts as a low-efficacy partial agonist at voltage-gated sodium channels (VGSC's) and as a high affinity inhibitor of voltage-gated potassium currents. It reduces the current through potassium channels irreversibly by stabilizing some of the closed channels. It acts as an intermembrane anchor where it displaces lipids and prohibits the voltage sensor domain of the channel from moving during physiologically important changes. This causes the channel to remain in the closed state and lowers the current. Gambierol also decreases the amplitude of inward sodium currents and hyperpolarizes the inward sodium current activation.
Gambierol has a high affinity for especially K1.1-1.5 channels and the K3.1 channel. K1.1-1.5 channels are responsible for repolarization of the membrane potential. The K1.3 channel however, has additional functions by regulating the Ca2+ signaling for T cells. If they are blocked, the T cells at the site of inflammation paralyse and are not reactivated. K3.1 channels are responsible for the high frequency firing of action potentials. If the K channels are closed, the depolarized membrane cannot repolarize to its resting state, causing a permanent action potential. This leads to paralysis of, for example, the respiratory system and therefore suffocation of the organism.
In neurons, gambierol has been reported to induce Ca oscillations because of blockage of the voltage-gated potassium channels. The Ca oscillations involve glutamate release and activation of NMDARs (glutamate receptors). This is however secondary to the blockade of potassium channels. The oscillations reduce the cytoplasmic Ca threshold for the activation of Ras. Ras stimulates MAPKs to phosphorylate ERK1/2 which induce outgrowth of neurites. This is however dependent on intracellular concentrations and interaction of the NMDAR receptors They both work bidirectionally.
An increase in intracellular calcium concentration also activates the nitric oxide synthase to produce nitric oxide. In combination with a superoxide, nitric oxide forms peroxynitrite and causes oxidative stress in different sorts of tissues. This explains the toxic symptoms derived from intake of gambierol.
Metabolism
Metabolism of gambierol is not known yet, but the expectation is that gambierol acts almost the same as the ciguatoxins. Ciguatoxins are polycyclic polyether compounds. Their molecular weight is between 1.023 and 1.159 Dalton. Gambierol is structurally similar to ciguatoxins and it can be synthesized together with them. Excretion of these ciguatoxins is largely via the feces and in smaller amounts via urine. The compounds are very lipophilic and will therefore diffuse to multiple organs and tissues, for example the liver, fat and the brain. The highest concentration was found in the brain, but muscles contained the highest total amount after a few days. Because gambierol is lipophilic, it can easily persist and accumulate in the fish food chain. The detoxification pathways are still unknown, but it is possible to eliminate the gambierol. This will take several months or years.
Efficacy and side effects
The membrane potential and calcium signaling in T lymphocytes are controlled by ion channels. T cells can be activated if membrane potential and calcium signaling are altered, because they are coupled to signal transduction pathways. If these signal transduction pathways are disrupted, it can prevent the T cells from responding to antigens. This is called immune suppression. Gambierol is a potent blocker of potassium channels, which for a part determine the membrane potential. Gambierol is therefore a good option for the development of a drug that can be used in immunotherapy. This is for example used in diseases like multiple sclerosis, diabetes mellitus type 1 and rheumatoid arthritis.
Treatment with gambierol is not being used yet, because the compound is toxic and also blocks other channels and thereby disrupts important processes. Intake of gambierol can also cause pain, because Kv1.1 and Kv1.4 channels are blocked and that increases the excitability of central circuits. It also causes illness for several weeks. This is explained by the fact that gambierol is very lipophilic. Lipophilic compounds have high affinity for the lipid bilayer of cell membranes. It is likely that gambierol remains in the cell membrane for days or a few weeks, which explains the long term illness associated with gambierol treatment. There are also other symptoms already explained by the mechanism of action of gambierol, for example difficulties with respiration and hypotension.
Gambierol is also an interesting compound in research into treatments of pathologies like Alzheimer's disease, which are caused by increased expression of β-amyloid and/or tau hyperphosphorylation. Increases in β-amyloid accumulation and/or tau phosphorylation affects neurons the most. The neurons will then be degenerated and therefore this process has effects on the nervous system. However, gambierol can reduce this overexpression of β-amyloid and/or tau hyperphosphorylation in vitro and in vivo.
Gambierols function in inducing outgrowth of neurites in a bidirectional manner can potentially be used after neural injury. After for example a trauma or a stroke, gambierol can be used to change the structural plasticity of the brain. The possibility of gambierol to cross the blood–brain barrier is very important in this case.
Toxicity
Poisoning by gambierol is normally caused after eating contaminated fish. Gambierol exhibits potent toxicity against mice at 50-80 μg/kg by intraperitoneal injection or 150 μg/kg when consumed orally. Symptoms resemble those of ciguatera poisoning. The symptoms concerning the gastrointestinal tract are:
Abdominal pain
Nausea
Vomiting
Diarrhea
Painful defecation
The neurological symptoms include:
Paradoxical temperature reversion; cold objects feel hot and vice versa.
Dental pain; teeth feel loose.
Treatment
There is no known antidote for gambierol poisoning.
References
Neurotoxins
Polyether toxins
Ion channel toxins
Non-protein ion channel toxins
Potassium channel blockers
Heterocyclic compounds with 7 or more rings | Gambierol | [
"Chemistry"
] | 1,986 | [
"Polyether toxins",
"Neurochemistry",
"Neurotoxins",
"Toxins by chemical classification"
] |
53,502,953 | https://en.wikipedia.org/wiki/Skysite | Skysite, stylized as SKYSITE, is a document management platform designed for construction and facility owners and managers. The cloud-based drawing management and distribution software allows the management of documents related to construction projects. Skysite includes features like RFI, Punch List and photo management. Skysite’s track and report functionality is designed to prevent mistakes and delivery delays. The system can be accessed to generate reports for all documents that are shared with the team. The reports can also be deleted, downloaded, or marked up to increase employee accountability.
Once constructed, facility managers can use Skysite to store, access, distribute, and manage the documents related to the operations of the building. As-builts, O&Ms, warranties and more can be organized and searched. Skysite’s real-time synchronization of documents allows access to current information whenever and wherever needed from tablets and mobile devices. All the building’s information can be archived and searched with custom attributes, along with document retention to mitigate risk.
History
Skysite was founded in 2015 with the goal of helping manage documents in active construction projects. Skysite offers users desktop sync and a mobile app that has been designed to add mobility to the industry.
Product
The software allows users to manage, view, collaborate, and distribute encrypted construction documents in real time on mobile device or desktop device. The app has been designed to store all critical information in the cloud, for local or offline access. It also has built-in mark-up tools to communicate issues. The offerings of the app includes improved hyperlinking of construction documents, image and more attachments to a Punch list item and document search. Users can upload documents and files with drag and drop, pictures can be pinned to construction drawings and RFIs can be answered. A sample project aids users in getting started.
Facility management professionals can manage, sync, organize, search and share important information from computers and mobile devices. Skysite allows to sync all documents with mark-ups, and annotations, along with revision updates, so that the team can uses the right information to make decisions. The revamped application program interface (API) of Skysite is designed to fit to an existing information technology infrastructure and integrate with other project applications. Skysite’s API integrates with various productivity tools including Google Drive Box, Dropbox, OneDrive, and Egnyte.
Skysite software can be accessed to reduce errors and inadequacies associated with paper-based document management systems during all the phases of construction. The system is designed to reduce information management costs, increase work efficiency, enable secure file access and sharing, and make collaboration better, easier, and faster. The Skysite mobile app is available on the iOS App Store and Google Play Store.
References
Construction software
Document management systems | Skysite | [
"Engineering"
] | 585 | [
"Construction",
"Construction software"
] |
53,504,436 | https://en.wikipedia.org/wiki/Fr%C3%A9d%C3%A9rique%20Vidal | Frédérique Vidal (born 9 May 1964) is a Monegasque-born French-based biochemist, academic administrator, and politician who served as Minister of Higher Education, Research and Innovation in the government of Prime Ministers Édouard Philippe and Jean Castex from 2017 to 2022. She was the president of the University of Nice from 2012 to 2017.
Early life
Vidal was born in Monaco. She was educated in Monaco and earned a master's degree in biochemistry from the University of Nice Sophia Antipolis. She earned a Master of Advanced Studies in molecular virology from the Pasteur Institute, and a PhD in biology from the University of Nice Sophia Antipolis.
Career
Vidal began her career as a biochemist for Virbac.
Vidal joined her alma mater, the University of Nice, as an associate professor in 1995. She became a full professor in 2002, and she served as the chair of the biology department from 2005 to 2008. There is no evidence that Vidal officially directed a thesis; she published one scientific peer-reviewed paper as last author and has an h-index of 14 (retrieved on Web of Science, February 2021).
She was the vice dean of its college of sciences from 2007 to 2009, and its dean from 2009 to 2012. She succeeded Albert Marouani as the university president in 2012. During her first term, Vidal founded Université Côte d'Azur, a consortium consisting of the university, and local business schools and research centres, to increase the international attractiveness of the university. She was re-elected as president in 2016.
Vidal was opposed to the circulaire Guéant, a failed proposal by Interior Minister Claude Guéant whose aim was to curtail the ability of non-EU foreign students to stay in France after the completion of their studies. She suggested the University of Nice should not discriminate on the basis of national origin or financial resources.
On 17 May 2017, Vidal was appointed Minister of Higher Education, Research and Innovation in the First Philippe Government.
In March 2019, Vidal criticized the Polish Institute of National Remembrance for its role in the disruption of Holocaust conference in Paris.
References
1964 births
French people of Monegasque descent
French women academics
Living people
Monegasque women
Pasteur Institute
Côte d'Azur University alumni
Academic staff of Côte d'Azur University
Women biochemists
Women government ministers of France | Frédérique Vidal | [
"Chemistry"
] | 479 | [
"Biochemists",
"Women biochemists"
] |
53,505,342 | https://en.wikipedia.org/wiki/Victor%20Mbarika | Victor Mbarika is an American professor from Cameroon. He is currently the Stallings International Distinguished Scholar and MIS professor at East Carolina University within the University of North Carolina System, in Greenville, North Carolina, United States. He is the President, Board of Trustees of the ICT University.
Education
Mbarika earned his Master's degree in Management Information Systems (MIS) from The University of Illinois at Chicago in 1997, and a Ph.D. degree in MIS from Auburn University in 2000.
Career and research
Mbarika's research is focused on ICT implementation in Africa, and has provided a theoretically informed framework for understanding ICTs in less developed countries. His work provides a base from which to begin to understand the contextual differences that dictate information systems research in less advantaged environments. He is founding editor-in-chief of The African Journal of Information Systems and senior board member for several academic journals internationally.
He is also the founder of the International Center for Information Technology and Development (ICITD), East Carolina University, Greenville, which focuses on advancing IT training and development in Sub Saharan Africa especially on e-health, e-education and e-democracy. In 2016, he was among the first recipients of the Fulbright-MCMC research grants.
In 2020, Premium Times reported that a spokesperson for Abdullahi Umar Ganduje, governor of Kano State of Nigeria, claimed that Ganduje had received a letter from Mbarika indicating Ganduje's appointment as a visiting professor at East Carolina University. East Carolina University later released a statement that confirmed Mbarika was part of its faculty but denied that the appointment was made and that Mbarika was authorised to make such an appointment at the university.
Other initiatives
Other initiatives facilitated by him include The ICT for Africa conference series (ICT4 Africa), African Journal of Information Systems (AJIS), the ICT University Foundation and Cameroon Youths for Jesus (CYJ). Through the ICT University Foundation, he has donated e-learning facilities to some universities in sub-Saharan Africa which is aimed to advance learning activities for economic and societal development.
Publications
Professor Mbarika has authored over 200 academic publications (books, book chapters, journals articles).
Selected books
Ayo, C. K. and Mbarika, V. (Eds.). (2017). Sustainable ICT Adoption and Integration for Socio-Economic Development. IGI Global, Hershey, Pennsylvania, USA.
Mbarika, V. and Adebayo, A. P. (2015). Information and Communication Technology for Secondary Schools. AGWECAMS Publishers.
Kituyi G., Moya, M. and Mbarika, V. (2013). Computerized Accounting and Finance: Applications in Business. Makerere University Business School.
Hinson, R., Boateng, R. and Mbarika, V. (Eds.). (2009). Electronic Commerce and Customer Management in Ghana. Accra, Ghana: Pro Write Publishing.
Kizza, J.M., Muhirwe, J., Aisbett, J., Getao, K., Mbarika, V., Patel, D. and Rodrigues, A. J. (Eds.). (2007). Strengthening the Role of ICT in Development. Fountain Publishers: Kampala, Uganda.
Sankar, C.S., Mbarika, V., & Raju, P.K. (2006). Use of Information Technologies in Businesses and Society: Learning Through Real-World Case Studies. Anderson, SC: Tavenner Publishers.
Raju, P.K., Sankar, C. & Mbarika, V. (2005). POWERTEL Case Study: Coverage of a Larger Area versus Better Frequency Re-Use in Wireless Communications. Anderson, SC: Tavenner Publishers.
Mbarika, V. (2001). Africa’s Least Developed Countries’ Teledensity Problems and Strategies. Yaounde, Cameroon: ME & Agwecam Publishers.
Honors and awards
Mbarika is a recipient of three lifetime achievement awards, for his "Outstanding contribution to computer science and telecommunications" and his "Contribution to ICT Research and Education".
He receipts African Achievers Award on July 14, 2023 in London, United Kingdom.
References
External links
ICITD
American scientists
20th-century American scientists
Auburn University alumni
Cameroonian scientists
Information systems researchers
Living people
Year of birth missing (living people) | Victor Mbarika | [
"Technology"
] | 897 | [
"Information systems",
"Information systems researchers"
] |
53,506,002 | https://en.wikipedia.org/wiki/List%20of%20condominiums%20in%20Las%20Vegas | Since the 1990s, various condominium projects have been proposed for the Las Vegas Valley. Park Towers and Turnberry Place, two high-rise condominium properties located near the Las Vegas Strip, were completed in 2001; they subsequently inspired a condominium boom that started in 2003, when various developers began announcing projects that were planned throughout the Las Vegas Valley.
Many projects were ultimately cancelled because of a rise in construction costs, as well as a lack of skilled construction workers and contractors who were qualified to build high-rises; both reasons were attributed to the large number of projects being announced. The following list includes notable condominium projects that were both completed and cancelled, as well as projects that are on hold.
History
Early history
Regency Towers, built in 1974, was the first high-rise condominium property to open in the Las Vegas Valley, with 226-units. The property was initially unsuccessful, selling only eight units before going into foreclosure. In the late 1990s, Las Vegas was the fastest-growing area in the United States. As a result, five new high-rise condominium projects were being planned for the Las Vegas Valley in 1998, for a total of 12 new condominium towers. Among the five proposed projects was Turnberry Place and Park Towers.
Condominium boom
High-rise condominiums became a popular trend in the Las Vegas Valley after the opening of Turnberry Place and Park Towers in 2001. Numerous high-rise condominium projects were subsequently announced beginning in 2003, starting a condominium boom. Real estate experts predicted that only 20 to 50 percent of the announced projects would actually get built. The condo-hotel concept was introduced in the Las Vegas Valley in September 2003, at MonteLago Village at Lake Las Vegas. At the end of the year, plans were underway for the first high-rise condominium in downtown Las Vegas: Soho Lofts.
The condominium boom was sometimes referred to as the "Manhattanization of Las Vegas". The term was first used in 1999, by Steve Bottfeld, the owner of a Las Vegas real estate consulting firm. The term was popularized by Richard Lee – director of public relations for First American Title Company – after he used it during a presentation. Lee was a well-known local proponent of the high-rise condominium boom, and spoke frequently about it at local conferences and seminars. Lee had used the term as early as 2003; it was later used as the title for Manhattanizing Las Vegas, a 2005 book by Paul Murad that chronicled the Las Vegas condominium boom. A website called Manhattanization.com was also created to cover the local high-rise market.
By January 2005, 122 high-rise condominium buildings with a total of nearly 17,000 units had been announced. The tallest proposed project was the 73-story Summit, which also had the most expensive price listed for a unit: $35 million. The lowest price was $139,900 for units at the 51-story Las Vegas Central. New condominium projects, when completed, were expected to create an increase in visitation to local casinos. Many of the proposed high-rise condominiums were to be built along the Las Vegas Strip in hopes of maximizing buyer interest.
The Krystle Sands high-rise, to be built on the Las Vegas Strip, became the first of the newly proposed condominium projects to be cancelled, in March 2005. By May 2005, there were plans for approximately 25,000 condominium units and 8,300 condo-hotel units in the Las Vegas Valley. Some condominium projects were aided by the publicity of celebrities who purchased units in them. As of December 2005, at least 70 condominium towers had been announced for the Las Vegas Valley during the previous 12 months. Multiple projects had been cancelled up to that point. Some developers sold their land to make back a profit. Most of the surviving condo projects were those situated on and near the Las Vegas Strip.
Many projects were cancelled because of rising construction costs, as well as a lack of skilled construction workers and contractors who were capable of building high-rise structures. The rising costs and limited workers were both attributed to the large number of high-rise condominium projects that were being planned. While most of the cancelled condominium projects did not have difficulty selling, their respective developers could not build the projects at a suitable cost due to construction expenses rising 30 percent to 50 percent. In February 2006, representatives from six projects announced the formation of the Las Vegas High Rise and Condominium Alliance, which would promote the mid-rise and high-rise condominium market in Las Vegas.
In April 2006, Murad – who was planning the 39-story Gateway Las Vegas condominium tower – stated that Las Vegas had entered its second phase of "Manhattanization", saying, "This first phase of Manhattanizing is over. Now we're entering the second phase. What happened in Las Vegas over the last few years is amazing, going from a couple of high rises to a hundred. That hasn't happened anywhere else in the world." The Platinum and The Signature at MGM Grand, the first projects near the Las Vegas Strip to offer condo-hotel units, were completed in 2006.
By that point, after the cancellations of several high-rise condominium projects, banks had become more resistant to developers who were seeking construction financing for proposed projects. Two banks were heavily involved in Las Vegas' high-rise condominium market at that time: Corus Bank and Hypo Real Estate Corporation. Corus had $770 million of its loan portfolio allocated to Las Vegas condominium projects, while Hypo had approximately $850 million allocated to such projects. During 2006, multiple condominium projects were under construction in downtown Las Vegas. Mayor Oscar Goodman, who was elected in 1999, had made it a priority to revitalize the downtown area. Sky Las Vegas, finished in 2007, was the first high-rise condominium to be completed on the Las Vegas Strip.
Economic downturn and resurgence
Sales of high-rise condominiums began to decrease in 2008. The condo-hotel market, consisting of projects on and near the Las Vegas Strip, also suffered that year because of low sales; thousands of condo-hotel units had been cancelled up to that point. By the end of 2008, only three additional developers had successfully completed condominium high-rises near the Las Vegas Strip: MGM Mirage (The Signature), Donald Trump (Trump International), and Andrew Fonfa (Allure Las Vegas). In 2009, condominium and condo-hotel units on and near the Las Vegas Strip were still struggling to sell because of the financial crisis of 2007–2008.
As of August 2009, less than 25 percent of the proposed condominium projects had been built, as predicted by some analysts; developers of projects that were completed were having difficulty selling their units as a result of the 2008 recession. Sales of high-rise condominiums increased seven percent in the third quarter of 2009, although condo-hotels continued to struggle. Poor condominium sales continued into the following year. In June 2010, there were 5,500 high-rise condominium units and 5,400 condo-hotel units in the Las Vegas Valley. By that point, developers of several high-rise condominium properties had begun renting their vacant units, which were left unsold because of the poor economy.
Sales of high-rise condominiums had increased in 2011, with many units being sold at a reduced cost through bank sales, short sales, and foreclosures to investors, who would subsequently improve and flip the units. The largest increase occurred at properties on and near the Las Vegas Strip. However, sales of new condominiums were down, and the condo-hotel market also continued to suffer. High-rise sales were expected to increase in 2015 as the market continued to recover.
By 2016, the construction industry in Las Vegas had been revived, although there were no plans for any new high-rise condominium projects. Prices for existing high-rise condominiums had increased by that time. Demand for high-rise homes on the Las Vegas Strip was projected to increase because of the opening of the T-Mobile Arena, as well as the announcement of an NHL expansion franchise and discussions about a potential NFL team in Las Vegas. Sales continued to increase through 2018, partly because of the relocation of the Oakland Raiders to Las Vegas.
Completed projects
Allure Las Vegas
Allure began construction in 2005. Located west of the Las Vegas Strip, it was completed in December 2007, and was the tallest residential building within Las Vegas city limits at that time, standing 41 stories high with a total of 428 units. The tower was built at a cost of $150 million. A second tower was cancelled because of poor sales in the first tower caused by the Great Recession, and because of an oversupply of condominium high-rises on the Las Vegas Strip.
Boca Raton
Boca Raton consists of two seven-story buildings with a total of 378 units, located south of the Las Vegas Strip. Groundbreaking took place in 2004, and the project ultimately opened in 2007. However, sales were poor due to the Great Recession, and plans for two additional buildings were canceled.
Jockey Club
The Jockey Club is located on the Strip, surrounded on three sides by the Cosmopolitan of Las Vegas. It consists of two 11-story towers with a total of 348 units. Of those units, 78 are wholly owned as condos, and the remaining 270 are fractionally owned through a timeshare program.
Development of the property began in 1972. Sales were initially sluggish, and most of the units were used as short-term rentals for several years. In 1977, the developers began converting units into timeshares. The timeshare program initially included 85 units, and later expanded to include most of the building. A second phase of construction was originally planned to add a third tower with 650 units on 30 floors, as well as a casino, restaurants, and showrooms. The casino was built in 1981, but never opened; instead, the developer went into bankruptcy, and the land was sold off.
After a series of ownership changes, the land was bought in 2004 by the developers who would build the Cosmopolitan. They decided to build around the Jockey Club instead of attempting to buy and demolish it because of the estimated $400- to $500-million cost of buying out all of the condo and timeshare owners.
Juhl
Juhl is a mixed-use development project that includes a 15-story condominium tower, in addition to restaurants and retail. It is located in downtown Las Vegas. Construction began in 2006, but the opening was delayed by more than a year, due to construction issues. It ultimately opened in 2009, and buyers initially had trouble finalizing their purchases due to the effects of the Great Recession. Some units were temporarily turned into rentals.
Manhattan
Manhattan is a 700-unit condominium property located on South Las Vegas Boulevard, south of the Las Vegas Strip. It was announced by Gemstone Development in 2004, and was built by Martin-Harris Construction.
The project cost $250 million, and the first of several buildings was completed in 2006. The building exteriors were designed to resemble the various architectural styles present in the borough of Manhattan. Units were priced low to appeal to a broad customer base.
Metropolis
Metropolis is a condominium tower with 71 units, located at 360 East Desert Inn Road, east of the Las Vegas Strip. It was built on less than an acre of land, previously occupied by a closed low-rise timeshare known as Royal Aloha.
Metropolis was developed by Randall Davis, who had previously developed other properties in Houston. He was attracted to the Las Vegas market following the success of Park Towers and Turnberry Place. The property is named after Davis' Metropolis condominium property in Houston, but it differs in appearance, featuring a 1920s Art Deco design inspired by the Argyle Hotel in California.
Davis purchased the land in July 2003, at a cost of $1.9 million. He demolished the Royal Aloha and broke ground on Metropolis in September. Construction began in January 2004, and the project was originally scheduled for completion that November. Although concrete and steel prices increased during construction, Davis chose not to raise prices on the units, ultimately breaking even. The tower was topped off in December 2004, and was opened the following December.
Newport Lofts
Newport Lofts is a 23-story, 168-unit tower located at 200 Hoover Street in downtown Las Vegas. The project was co-developed by Sam Cherry, who also developed Soho Lofts. In August 2004, Cherry was planning Newport Lofts as a 17-story tower with 131 units, to be built at the northeast corner of Casino Center and Hoover Avenue. The project was a joint venture between Cherry and Seegmiller Partners, a company based in Newport Beach, California, with Clark and West Seegmiller as its principals. The property for the project had been purchased several years earlier by Clark Seegmiller.
In October 2004, the Las Vegas City Council approved Newport Lofts as a 22-story tower with 168 units. Groundbreaking was to begin in late May 2005, with completion expected in fall 2006. Reservations began in January 2005, while groundbreaking began in early July 2005, with Breslin Builders as the project's general contractor. Completion was expected for 2007. That month, the project received $81 million in construction financing from George Smith Partners, based in Irvine, California. In March 2006, the elevator shaft and center staircase had been built up to the 12th floor, while shear walls were up to the eighth floor.
Construction was still underway in August 2007, although some new residents had already begun moving into the building by that time. More than 70 percent of the building's units had been sold up to that point. Construction concluded at a cost of $115 million. Corus Bank helped financed the project for $67.1 million. West Seegmiller said Newport Lofts was designed with a Southern California theme, as its target demographic was California residents who desired to purchase a second home in Las Vegas. In 2007, Newport Lofts won a Mayor's Urban Design Award.
In January 2008, an auction of 60 units was cancelled after Pyramis Global Advisors – a division of Fidelity Investments – took over management of the building. Condo prices at Newport Lofts were decreased 30 percent later that year. At the end of 2008, artist Brett Sperry opened the Brett Wesley Gallery inside his penthouse at Newport Lofts. When Corus Bank failed in September 2009, the property was acquired by ST Residential. In April 2011, ST Residential announced that the last of Newport Lofts' units had been sold to buyers.
One Las Vegas
One Las Vegas consists of two 20-story towers, located south of the Las Vegas Strip. Construction was underway in 2006, and the project opened in June 2008.
One Queensridge Place
One Queensridge Place, located in Summerlin, began construction in 2005. The project was finished two years later, at a cost of $400 million. One Queensridge Place consists of two 18-story towers with 219 condominium units, and is located on part of a property near the Suncoast Hotel and Casino and the Tivoli Village shopping mall.
Palms Place
Palms Place is a 47-story condo hotel tower with 599 units, located next to the Palms Casino Resort. It began construction in 2006, and was opened in 2008.
Panorama Towers
Panorama Towers was announced in September 2003, and began construction the following year. The first tower was opened in 2006, followed by a second tower in 2007. Both towers stand 33 stories high, and were built at an estimated cost of $300 million. A third tower, standing 45 stories, was renamed as The Martin in 2011, and received a $3 million renovation to increase sales. The complex is located west of Interstate 15 and CityCenter.
Park Towers
Park Towers is a two-tower, 20-story condominium property with 84 units, located east of the Las Vegas Strip. Park Towers was announced by developer Irwin Molasky in 1998, and began construction the following year, with Steve Wynn as a co-developer. The project was completed in 2001.
Regency Towers
Regency Towers is located at 3111 Bel Air Drive, at the Las Vegas Country Club in Winchester, Nevada. Regency Towers was built in 1974, and was the first high-rise condominium property to open in the Las Vegas Valley, standing 28 stories with 226 units. Only eight of the units sold after opening, before the property went into foreclosure. Irwin Molasky, who was among the eight buyers, later purchased the entire structure and renovated it before ultimately selling the remaining units. Regency Towers was designed by Las Vegas architect Homer A. Rissman, who also lived at the property for years. In March 2001, approximately 80 residents were evacuated after the explosion of a meth lab operated by a resident inside one of the condominiums. In March 2007, six weeks of filming began at Regency Towers for the second season of the television series HGTV Design Star. The season was shot inside the penthouse formerly owned by Molasky.
Notable tenants at Regency Towers have included George Carlin, Don Miguel Ruiz, Hank Greenspun and his wife, Shaun King, musician Larry Hart, Norm Clarke, casino executive Burton Cohen, Russian-art collector Dr. Rupert Perrin, Sandra Murphy, and Anthony Spilotro. Moe Dalitz owned a penthouse unit until his death there in 1989; his unit, which included his furniture and books, was for sale in 2002 at a cost of $1.2 million. Also for sale at that time was Rodney Dangerfield's unit, at a cost of $275,000. Actress Debbie Reynolds, who purchased a condominium unit on the 12th floor in 1974, put her unit up for sale in 2011, at a cost of $269,900. La Toya Jackson owned a unit from 1996 until 2009, when it was foreclosed.
Sky Las Vegas
Sky Las Vegas is a 45-story tower with 409 condominium units that is located on the Las Vegas Strip. Sky Las Vegas was announced in July 2004, and was opened in May 2007, becoming the first high-rise condominium project to be completed on the Las Vegas Strip.
Soho Lofts
Soho Lofts, named after the Manhattan neighborhood of SoHo, is a 16-story condominium tower with 112 units, located within the city's arts district at 900 South Las Vegas Boulevard in downtown Las Vegas. The project was developed by Sam Cherry, who also developed Newport Lofts. Cherry and his father-in-law, Harris Rittoff, were planning Soho Lofts in December 2003. JMA Architecture Studios designed the project. Soho Lofts was to be built at a cost of $40 million to $50 million, on of vacant property at the southwest corner of South Las Vegas Boulevard and Hoover Avenue. It was the first high-rise condominium project to be announced for the downtown area. Groundbreaking was scheduled for May 2004. The project was to include of ground-level retail space. The property was purchased in January 2004, at a cost of $1.2 million.
The project's general contractor was Breslin Builders. Digging for the building's support columns began in July 2004. Construction was expected to cost $60 million. Crews were preparing to begin the structure's foundation work in October 2004. Occupancy was initially expected for early December 2005. Occupancy was later expected for February 2006, although construction was ongoing in April 2006.
In May 2006, an automobile dealership – for Lamborghinis, Ferraris, and Rolls-Royces – was being planned for the building's ground floor, while residents were expected to begin occupying the building later that month. In December 2007, a lease was signed for the Dust Contemporary Fine Art gallery to occupy a space inside Soho Lofts. The gallery opened two months later. Globe Salon was the first business to occupy Soho Lofts' commercial space, beginning in July 2008; the rest of the space remained vacant because of the poor economy.
By 2009, the Naomi Arin Contemporary Art gallery was operating inside Soho Lofts. In January 2011, a small grocery store, Resnicks Grocery, opened inside a space inside Soho Lofts that was previously occupied by an art gallery. A lounge, known as The Lady Silvia, opened inside Soho Lofts in July 2011. The Amanda Harris Gallery opened inside Soho Lofts in January 2012. The Contemporary Arts Center later operated from within one of Soho Loft's ground-level spaces. As of April 2023, Globe Salon, The Goodwich restaurant (which remodeled the former Resnicks Grocery space), and Millenium Fandom bar (which took over the former Lady Silvia bar) were all operating in Soho Lofts, which is within the Downtown Las Vegas Arts District.
The Ogden
The Ogden, located in downtown Las Vegas, was initially opened as the Streamline Tower in May 2008. It opened with 275 condominium units in a 21-story tower, although sales suffered as a result of the weak local and national economy. The units were converted into apartments in 2010, and the property was renamed as The Ogden a year later. In 2014, The Ogden was converted back into condominiums.
The Platinum
The Platinum is a 17-story, 255-unit condo hotel built on of land, east of the Las Vegas Strip. The project was developed by Platinum Condominium Development, LLC, a joint venture of Diversified Real Estate Concepts, Inc. and Marcus Hotels and Resorts. Construction began in 2005, and the project opened in October 2006.
The Signature at MGM Grand
The Signature is a condo hotel located near the MGM Grand Las Vegas resort. The project was jointly developed by MGM Mirage and Turnberry Associates, and opened in 2006, on the former land of MGM Grand Adventures Theme Park.
Trump International
Trump International is located near the Las Vegas Strip. Groundbreaking took place in 2005. The 64-floor tower was built on of property that had been used as part of the Frontier's rear parking lot. The project cost $500 million, and was opened in 2008, with a total of 1,282 condominium units and hotel rooms. A second tower had been planned, but was postponed due to poor economic conditions. Construction of the second tower had been expected to begin in late 2008.
Turnberry Place
Turnberry Place was announced in June 1998, and consists of four 40-story condominium towers located east of the Las Vegas Strip.
Turnberry Towers
Turnberry Towers is a two-tower property near the Las Vegas Strip. The towers stand 45 stories and contain a total of 636 units.
Vdara
Vdara is a condo hotel located within CityCenter on the Las Vegas Strip. It opened in December 2008, and includes 1,495 units.
Veer Towers
Veer Towers, also located within CityCenter, consists of twin towers that stand 37 stories high and include 670 condominium units. The towers opened in July 2010.
Waldorf Astoria Las Vegas
The Waldorf Astoria hotel includes 225 condominiums and is located within CityCenter. It was opened in December 2009 as the Mandarin Oriental, and rebranded as the Waldorf Astoria in 2018.
Proposed projects
Four Seasons
Four Seasons Private Residences Las Vegas is a $1 billion condominium project. It is being constructed on 11 acres in the community of MacDonald Highlands, located within the city of Henderson, itself a part of the Las Vegas Valley. The project will include 171 units, spread across two towers rising 24 and 25 stories. It will be the first high-rise structure in Henderson, and the first new condominium high-rise in the Las Vegas Valley since Veer Towers, finished in 2010.
The project was announced in November 2021, by Azure Resorts and Luxus Developments, and was originally known as Pinnacle Residences at MacDonald Highlands. It was conceived by Azure founder Jim Reilly, a resident of nearby Seven Hills who had become personally interested in high-rise living. He soon found that there was demand for a high-rise condominium property in Henderson. In 2023, a branding and management deal was announced with Four Seasons Hotels. Site preparation began that year, and construction is expected to conclude by 2026.
On hold
St. Regis Residences
An unfinished condominium tower, known as "The St. Regis Residences at the Venetian Palazzo, Las Vegas", is located on the Las Vegas Strip, between the Palazzo and Venetian resorts. Construction was underway in 2007, and the opening was eventually scheduled for March 2010. The tower was to stand 50 stories, with a total of 398 condominium units. The project was expected to cost $600 million, but construction was indefinitely suspended in November 2008 because of the Great Recession. In 2014, the project was no longer expected to be finished as a condominium tower because of uncertainty in the high-end, high-rise residential market. Up to that point, several other options had been considered regarding the building's future use.
Cancelled projects
Ambling Development Company project
In 2004, the Atlanta-based Ambling Development Company held meetings with mayor Oscar Goodman, councilman Lawrence Weekly, and other city officials regarding a condominium project. Ambling was planning a complex of three 28-story condominium towers with a total of 840 units, to be built at a cost of $330 million on at the northwest corner of Alta Drive and South Martin Luther King Boulevard. The land had previously been occupied by a gas station, which was later burned down during a riot.
Ambling invested $2 million to acquire the land, to open a Las Vegas office, and to perform initial design work. Months later, on December 15, 2004, the City Council voted unanimously to reject Ambling's project because of opposition from nearby residents, who believed that the tall modern-style glass buildings would not go well with the neighborhood's southwestern theme and its 600 single-story houses. Residents also believed the new project would create traffic problems and overcrowd nearby schools. Weekly criticized city staff members, alleging that they misled Ambling to believe that their project was guaranteed to be approved by the City Council. The manager of the city's Economic Development division, who had worked with Ambling on their project, resigned from his position two days after the vote.
In June 2005, Ambling was unanimously approved by the City Council for a smaller version of its initial project to be constructed on the same property. The new project was to consist of three nine-story buildings and one five-story building, with retail space and a total of 664 condominium units. The project was to be built in phases, with construction planned to begin at the end of 2005, and the first phase being potentially completed in 2007. The project was ultimately cancelled due to further opposition from nearby residents. The land was subsequently sold in February 2006.
Aqua Blue
By December 2004, the newly created high-rise development division of Prudential Americana Group Realtors was planning Aqua Blue, a luxury condominium-hotel project. Aqua Blue was the division's flagship project, with gross sales expected to exceed $550 million. The project was approved that year, and was to be constructed east of the Las Vegas Strip near the intersection of Flamingo Road and Koval Lane, on of property that was occupied at the time by a Super 8 motel, located adjacent to the Ellis Island Casino & Brewery. The motel was to be demolished to make room for Aqua Blue, while Ellis Island would continue operations but would receive an exterior renovation to match the appearance of the new project.
Aqua Blue would have included a casino that would be operated by Gary Ellis, who owned the Ellis Island. Ellis decided to become involved in the Aqua Blue after meeting with the project's developer, Michael Peterson, who had developed and owned condominiums and restaurants in Wisconsin and Chicago. Aqua Blue was to stand 46 stories, and would have included 825 units, priced between $399,000 and $1,125,000. The project's expected cost was $600 million. Construction was expected to begin in fall 2005, and its opening was expected to occur by fall 2007.
In January 2005, retired basketball player Michael Jordan became involved in Aqua Blue. Jordan was to open two restaurants at Aqua Blue: Michael Jordon's Steak House and Michael Jordon's 23 Sportcafe. Jordan would also open the Michael Jordan Athletic Center inside the new building. In June 2005, Peterson began considering offers for the property. After three weeks, Peterson announced on June 29, 2005, that the project had been cancelled due to a large increase of proposed nearby condominium projects and a lack of buyers to sustain the increase. The property was sold to David Schwartz and his Chicago-based company, Waterton Associates, with plans to keep the Super 8 motel operational.
Champions of Las Vegas
Champions of Las Vegas was to consist of a 21-story tower with 844 condominium units that would be priced at approximately $1 million each. The project was being planned in 1995, and by March 1998, it had received approval by the Clark County Commission. The project was to be located near the southern entrance to Red Rock Canyon National Conservation Area. As of 1998, the project was scheduled for completion in 2006, because of the necessity to perform extensive infrastructure work on the property.
Charlie Palmer Hotel
The Charlie Palmer Hotel was announced by chef Charlie Palmer in April 2006. The project was to include a 35-story boutique condo hotel with 400 to 500 rooms, and initially was to be built at the intersection of Tropicana Avenue and Dean Martin Drive. The $400 million project was scheduled to break ground later in 2006, with completion expected for mid-2008. The project's proposed location was later changed to Symphony Park in downtown Las Vegas, with the condominium aspect removed.
Cielo Vista
In March 2005, the Seattle-based Northwest Resource Management Group filed plans with the city of Las Vegas for Cielo Vista, a 25-story condominium tower with 414 units, as well as of commercial space on the first floor. Above the first floor would be six floors used for parking, and 18 floors for condominium units. The project was designed by Las Vegas-based MWT Ofra, and was scheduled for a vote by the Las Vegas Planning Commission and the City Council in May and June 2005, respectively.
Cielo Vista would have been the company's first Las Vegas project. The company had previously developed single-family residential homes in California, as well as an 11-story building in Seattle. Cielo Vista was to be built at the southeast corner of East Washington Avenue and Veterans Memorial Drive, west of Cashman Field and north of downtown Las Vegas, on a 2.8-acre site that the company purchased for $1.2 million on March 29, 2005. A local expert believed that the project was in a bad location: an older part of Las Vegas with little development. The area was also known for a high rate of crime and homelessness; Steve Hartley, a partner for Northwest Resource Management Group, said the company had previously developed a project in California that had similar demographics.
The low price of the land allowed the company to sell condominium units ranging from to at a starting price of $295,000, and exceeding $500,000. Condominium units in the project could be reserved for a refundable fee of $5,000, compared to a $25,000 fee that was being charged by some other high-rise condominium projects in the city. Construction was expected to begin in late 2005, as long as the project received approval from the city. Completion was expected by early 2007. The project received unanimous approval from the Las Vegas Planning Commission in June 2005. At the time, 155 units had been reserved.
Three months after the announcement of Cielo Vista, Northwest Resource suspended sales and delayed the project because of rising construction costs, choosing instead to wait until it was further along in the construction cost process before beginning sales; 300 units had been reserved up to that point, and some buyers received a refund. As final construction costs were being determined in March 2006, Eric Radovich, Northwest Resource's managing director of public relations and marketing, said, "We're getting close to a number and we think it's real. We didn't feel we could tell people truthfully what the product was going to cost and whether we can afford to build it." The project never materialized.
Club Renaissance
The Club Renaissance was announced in 2005, and would have been built in downtown Las Vegas. It would consist of a 60-story tower, and was planned as the least-expensive high-rise condominium in the Las Vegas Valley. The tower, expected to be 702 feet high, was one of the taller high-rise projects to be approved for the downtown area. The project was affected by rising construction costs, and it ultimately did not materialize.
Elysium
By 2008, ex-NBA player Jackie Robinson and real estate veteran Michael Bellon had teamed up to develop a multibillion-dollar project on Bulloch and Gaffin's property called Elysium. It called for condos and hotel rooms, a dome-covered ocean-beach swimming complex, and more. It was to be located on the southeast of the Las Vegas Strip.
Icon
In November 2004, Jorge M. Pérez and The Related Companies were planning Icon, a twin-tower condominium project to be built on of property, located on the Las Vegas Strip at the northeast corner of Convention Center Drive. The land was located east of a Ross department store, and the project would be built behind the store. Related purchased the vacant land in January 2004, at a cost of $15 million. The land had previously been owned by Luke Brugnara, who also owned the adjacent Silver City Casino. Initially, Icon was to include two 47-story towers, standing 500 feet, with a total of 502 luxury condominiums, all facing the Las Vegas Strip. Two-thirds of the project's units would include views on both sides of the buildings for views of the Las Vegas Strip and nearby mountains. Unit prices would start at $500,000. The $30 million project was designed by Bernardo Fort Brescia of Arquitectonica, which teamed up with interior designer Yabu Pushelberg for the project. Construction on the first tower was to begin in 2005, with work on the second tower scheduled to begin after the first was completed.
By April 2005, the project had been redesigned after Lorenzo Doumani, developer of the adjacent Majestic Las Vegas, raised concerns about the Icon blocking views for tenants at the Majestic, among other issues. By that time, M.J. Dean had signed on as the general contractor for Icon, and the first tower was expected to take 18 to 24 months to construct. At that point, the towers were expected to be 48 stories high, with a total of 514 units. The Clark County Commission approved Icon in April 2005, despite objections from Doumani, who then filed lawsuits against Related. Later that month, a lawsuit was filed against Related by Sasson Hallier Properties LLC, developer of Panorama Towers. The two companies had previously negotiated a possible joint venture for the Panorama Towers project, and Sasson Hallier provided various database information – including contracts, financials, and marketing information – to Related as part of the negotiations. Ultimately, negotiations failed, and Sasson Hallier alleged that Related kept the database information to develop its Icon project.
In January 2006, Related announced the cancellation of Icon despite that buyers had signed contracts for most of the project's 514 units. Related stated, "In the several months needed to resolve lawsuits and finally be in a position to break ground, construction prices had increased so drastically that after pursuing every possible way to move forward, Related was unable to build Icon based on original pricing without seriously impacting the integrity of the development." A decrease in high-rise sales was also a factor in the cancellation. In May 2006, a lawsuit was filed by buyers against Related, stating that the company had no right to cancel purchase agreements for Icon's units.
Krystle Sands
Krystle Sands would have featured a 45-story condo hotel, to be built on the Las Vegas Strip. Construction was to begin in 2004, but developer F.W. "Freddie" Schinz eventually sold the land to Turnberry Associates, which used the site for part of its Fontainebleau resort.
Las Ramblas
Las Ramblas was announced in 2005, as a joint project between Centra Properties and The Related Companies. The $3 billion project was planned as a mixed-use complex that would have included 11 high-rise buildings, which would be used for hotel rooms and condominiums, with a total of 4,400 units. Las Ramblas was to be built east of the Las Vegas Strip on Harmon Avenue. Later in 2005, actor George Clooney and nightclub developer Rande Gerber announced that they would invest in the project. Because of a declining market and rising construction costs, Las Ramblas was cancelled in 2006, before the start of construction.
Las Vegas Plaza
Las Vegas Plaza was planned as a multibillion-dollar resort on the site of the demolished New Frontier hotel and casino. The project was to include 2,600 condominium units. The project never materialized, and in 2014, the property was sold to Crown Resorts, which planned to build the Alon Las Vegas on the site.
Liberty Tower / Monument / Stratorise
Liberty Tower was announced in June 2004, as a 21-story building to be built on at 1801 South Las Vegas Boulevard, at the southern end of downtown Las Vegas. The project would be located north of the Stratosphere tower and near the Las Vegas Arts District, on land that was purchased for $900,000. The project was designed by JMA Architecture Studios and was to be developed by Harvard Securities of Australia. Groundbreaking was expected by November 2004, with completion occurring a year and a half later at a cost of $35 million.
In August 2004, the 21-story project was approved by the Las Vegas City Council to include 18 condominium units, 116 apartments, and of ground-level retail space. That month, it was announced that Australian developers Joseph Di Mauro and Victor Altomare would finance the project, which they also planned to do for The Summit. By January 2005, the closed Holy Cow Casino and Brewery (the planned future site of The Summit) had been converted into a $1 million sales office for Liberty Tower. At that time, construction on the project was expected to begin in July 2005, with a cost of $100 million.
Construction of Liberty Tower never began. In December 2005, Altomare sold the property for $5.5 million to Stratorise South, a limited liability company based in Nevada. That month, plans were announced for a $105 million condominium project called Monument to be built on the property. The project was to be 22 stories, with 236 units, and was to be developed by Constellation Property Group, an Australia-based company owned by Eugene Marchese, with financing by partner David Rifkind. By August 2006, a new project known as Stratorise was being planned for the property. The project would stand 517 feet, and would include 45 stories. In September 2006, a hearing on the proposed project was delayed until November 1, 2006, at the request of the owner.
Majestic Las Vegas
Majestic Las Vegas was announced in 2004, and was to be built on the property occupied by the La Concha Motel on the Las Vegas Strip. Majestic Las Vegas initially was to consist of a 42-story tower, although the project later went through several redesigns, before being cancelled in 2007.
ManhattanWest
ManhattanWest was a mixed-use project that was to include 700 condominium units upon completion. It was proposed by Gemstone Development, which also created the Manhattan project. Construction was suspended in 2008, because of financial problems, and the project was ultimately finished as The Gramercy, with the condominium units opening as apartment rentals instead.
One Las Vegas / Vegas 888
In August 2004, Chris DelGuidice, who was developing Vegas Grand through his Del American company, announced plans for a second project to be known as One Las Vegas. The project would include a 565-foot 50-story condominium tower with 542 units, to be built at a cost of $500 million on 10 acres of land on Flamingo Road, east of the Palms Casino Resort. DelGuidice negotiated for a year and a half to purchase the property.
Early design plans included a 400-foot waterfall, rooftop hot tubs, a dance floor, a gourmet grocer, restaurants, a pool with cabanas, a health spa on the 35th floor, valet and housekeeping services, 24-hour concierge, a pet park, and a business center. Sales were expected to begin in early 2005, with prices starting at $500,000 and exceeding $10 million. Groundbreaking was reported to be a year away. The following month, construction was scheduled to begin in summer 2005. The project was to be financed by Lehman Brothers, with a loan of up to $79.45 million. Lehman Brothers also financed Vegas Grand.
Del American closed escrow on the property in January 2005, at a cost of $50 million. In February 2005, Amland Development took legal action against Del American to continue using the name for its own condominium project, also known as One Las Vegas. Amland Development won the right to use the name. In November 2005, Del American announced that the project would be named Vegas 888. The sales office for Vegas 888 closed in July 2006, at which point the property was reportedly for sale. Approximately $250 million worth of condominium units had been presold, with approximately $75 million spent on the project, most of which came from Lehman Brothers. In August 2006, Del American announced intentions to instead build a mixed-use resort, hotel and casino on the property.
The new project remained un-built. In 2007, the property was foreclosed and acquired by Lehman Brothers. Christopher Beavor, a Las Vegas investor, purchased the property in 2016, at a cost of $13.5 million. Beavor's initial, unfinalized plans included retail space, a five-story apartment complex, and a hotel, with construction expected to begin in six to seven months. Ultimately, Beavor decided to build a Delta hotel on the property. Groundbreaking took place in 2019, with a scheduled opening in 2021.
Opus Las Vegas / unnamed mixed-use project
The Opus Las Vegas was approved in November 2004, and was announced on March 25, 2005, at a conference that was related to high-rise development and was held at the Bellagio resort on the Las Vegas Strip. The $550 million project would have consisted of two 50-story towers with 350 condominium units each, for a total of 700. The project, to be developed by The Congress Group of Boston, was planned for a property that was presently occupied by the city's Scandia Family Fun Center, located west of the Las Vegas Strip at 2900 Sirius Avenue. Up to that point, The Congress Group had spent a year determining construction costs. Scandia and The Congress Group agreed to delay the initial escrow closing date of May 2005, so that final costs for the new project could be completed. As part of the agreement, the Scandia fun center would remain open through the summer, its busiest period, before its scheduled closing date on September 6, 2005.
At the time of the announcement, the property was in the process of being sold by Highrise Partners to The Congress Group for an undisclosed amount of money, with escrow expected to close in September 2005. Groundbreaking was expected to occur in the first quarter of 2006, with the first units available for occupancy in spring 2008. Opus Las Vegas would have featured 1,400 parking spaces spread across four levels, along with of residential retail stores. A pool would be located on the property's six-story deck. Floor plans would have ranged from , and would have come in one-, two-, and three-bedroom designs, while the top two floors would be occupied by two-story penthouses. Prices would have ranged from $200,000 to more than $4 million. Developer Michael Jabara said the project would offer "a metropolitan lifestyle for people who really want it all, great views, easy access to nearby neighborhood amenities, but at the same time it's an urban project."
In June 2005, Scandia said their fun center would remain open as the property had not been sold. On September 7, 2005, Fisher Brothers purchased the property occupied by Scandia, as well as nearby land. In December 2006, Station Casinos and Fisher Brothers announced a joint venture to develop a mixed-use project on up to of land, including the property of the closed Scandia fun center, which was demolished in 2007. As of July 2007, the mixed-use project was to be developed on nearly of land, which had been zoned for several thousand high-rise condominium or hotel units, and would have connected to Station's nearby Palace Station resort. Details about the new project's construction and costs were still undetermined at that time. In 2011, a business named Dig This opened on the vacant property, allowing customers to take control of an excavator on the dirt lot.
Paramount Las Vegas
Paramount Las Vegas was a casino, hotel, and condo resort with more than 1,800 units that was being planned by Royal Palms Las Vegas, a subsidiary of Royal Palms Communities. The project was to replace the Klondike Hotel and Casino at the south end of the Las Vegas Strip, beside the Las Vegas welcome sign. The resort was approved in October 2006, but an investor pulled out of the project in August 2007, and the land was put up for sale in May 2008.
Pinnacle
Pinnacle was to include two 36-story towers, near The Orleans hotel-casino. The project was announced in 2005, and was delayed several times before its cancellation in 2008, as a result of financial issues caused by the Great Recession.
Red Rock project
Announced in July 2005, as a joint venture between Station Casinos and developers Stephen Cloobeck and Steven Molasky. The project was to be built on the same property as the adjacent Red Rock resort, and was known under the names "Red Rock Residences" and "The Residences at Red Rock". The partnership dissolved in 2006, and the project was ultimately cancelled.
Rocker Tower
In 1995, Thomas Greenough relocated his bar and restaurant, Tommy Rocker's, to Dean Martin Drive, west of Interstate 15 and the Las Vegas Strip. In 2004, Greenough began receiving numerous offers from condominium developers for the one-acre lot that Tommy Rocker's occupied. Greenough, who was unable to work out a deal with potential developers that would incorporate Tommy Rocker's into any planned condominiums, later chose to build his own condominium on the property. In January 2006, Greenough received approval for a 46-story, 252-unit condominium tower, to be constructed on his property at a cost of $150 million. The structure was to be named Rocker Tower.
The tower was expected to be the first in southern Nevada to feature a computerized automated parking structure, with the intention of saving space and decreasing pollution. Greenough had toured Viennese parking garages as part of his research into automated-garage technology. Greenough hoped that the building would be certified by the Leadership in Energy and Environmental Design Green Building Rating System. Construction was expected to begin approximately one year later, with completion expected in summer 2008. Later in 2006, construction was scheduled to begin in fall 2007, with completion scheduled for January 2009. By January 2007, Greenough had shelved his plans to build the condominium due to increasing labor and material costs in the Las Vegas Valley.
Sandhurst
The Sandhurst was announced in 2004. The project, to be located in downtown Las Vegas, would have included a 35-story tower with 398 units. The tower would have also included commercial space for shops and restaurants. Groundbreaking was initially planned to begin in March 2005, with completion expected by September 2006. However, construction was delayed several times because of rising construction costs. The project was ultimately cancelled in 2007.
The Harmon Residences
The Harmon hotel, located within CityCenter, initially was to include 207 condominiums. Construction on the building stopped in 2008, after structural defects were discovered. MGM later had the building demolished in 2015.
The Summit / Ivana Las Vegas
Originally announced as The Summit in August 2004, and renamed as Ivana Las Vegas in 2005, when Ivana Trump became involved in the project. Ivana Las Vegas would have consisted of a $500 million, 73-floor tower with 945 condominium units. The tower was to begin construction in summer 2006, at the north end of the Las Vegas Strip, on of land that was occupied by the closed Holy Cow Casino and Brewery at the time. Ivana Las Vegas had been scheduled for completion in December 2008, but was cancelled in December 2005, due to rising construction costs.
Vegas Grand
Vegas Grand was announced by developer Del American in 2003, and initially was to consist of 440 apartments and 440 condominiums. The apartment aspect was removed later that year because of rising construction costs, with all 880 units to be used as condominiums. Construction began east of the Las Vegas Strip in March 2006. Vegas Grand was co-financed by Lehman Brothers, which took over the project in 2007, after Del American defaulted on its loan. The project was ultimately completed as an apartment complex known as Las Vegas Grand.
Viva
In 2005, Station Casinos started purchasing land next to the Wild Wild West Gambling Hall & Hotel it already owned. While no specific plans have been announced, it is widely expected that this move means that a major redevelopment is planned at this location.
According to an article in Forbes, the site has evolved to nearly 1/2-square-mile or at a cost of $335 million. With a working title of Viva, the three casino, hotel condo arena project would wind up costing $10 billion.
W Las Vegas
W Las Vegas was announced as a condo hotel in 2005. The project was expanded in 2006, after the purchase of adjacent land that was to be used for Las Ramblas. W Las Vegas was cancelled in 2007, before beginning construction.
See also
List of Las Vegas casinos that never opened
List of Las Vegas Strip hotels
References
Condo
Las Vegas
Condominiums in Las Vegas | List of condominiums in Las Vegas | [
"Engineering"
] | 10,337 | [
"Architecture lists",
"Architecture"
] |
53,506,177 | https://en.wikipedia.org/wiki/William%20Schooling | Sir William Schooling (16 December 1860 – 18 February 1936) was a British expert on insurance and statistics. He was named a CBE in the 1918 Birthday Honours and a KBE in 1920 for his work with the War Savings Committee.
Schooling was the editor of Bourne's Directory, a listing of British insurance companies, and the author of several books on insurance and on the history of the Hudson's Bay Company.
With Mark Barr, he also did pioneering work on the mathematics of the golden ratio.
References
External links
1860 births
1936 deaths
British statisticians
Golden ratio | William Schooling | [
"Mathematics"
] | 115 | [
"Golden ratio"
] |
53,506,444 | https://en.wikipedia.org/wiki/Unequal%20hours | Unequal hours are the division of the daytime and the nighttime into 12 sections each, whatever the season. They are also called temporal hours, seasonal hours, biblical or Jewish hours, as well as ancient or Roman hours (). They are unequal duration periods of time because days are longer and nights shorter in summer than in winter. Their use in everyday life was replaced in the late Middle Ages by the now common ones of equal duration.
The first temporal hour of daylight begins at sunrise, the first of night at sunset. For example, if daylight and night are each divided into twelve temporal hours, midday and midnight are each the beginning of the seventh hour.
A clock that displays the temporal hours is called a temporal clock.
Astronomical basics
To the concept of light day corresponds the astronomical concept Day arc of the Sun. With the exception of the equator, the duration of daylight depends on the latitude and the season. At 49° north/south latitude (e.g., in Karlsruhe), it varies between 16 equinoctal hours in summer and 8 equinoctial hours in winter.
Due to the continuous change of the duration of daylight over the course of the year, the duration of the day division, i.e. the temporal day hours and the temporal night hours, also changes over the year.
The temporal hours of day and night are equal only at the spring and autumn equinoxes.
From 66.5° north/south latitude (polar circles) the sun no longer sets (the horizon) every day in summer and rises every day in winter. Day does not occur.
History
Temporal hours were common in many cultures. A division of day and night into twelve hours each was first recorded in Ancient Egypt. A similar division of day and night was later made in the Mediterranean basin from about Classical Greek Antiquity into twelve temporal hours each ().
In Western culture they were adopted from the Roman calendar and were adopted in the European Medieval era. They had particular relevance in the fixed daily schedule of the monastic orders. This division of time allowed the work of the day -such as eating, praying, or working -to always be performed at the same (temporal) hour, regardless of season (Prayer of the Hours).
This chronology is used by Jewish religious law (Halacha), hence the Jewish Halachic division of hours.
Mechanical clocks encouraged the adoption of equinoctial hours.
Temporal time
For the display of temporal hours almost exclusively the sundial with as hand was once used. The position of the Sun, which varied throughout the year, served as a parameter on which the varying duration of the temporal hours during the year depended.
Many astronomical clocks created during the transition to the equal-duration equinoctial hours display temporal hours in addition to the new equal-duration hours.
Even where temporal hours continued to be used (especially in monasteries), the mechanical clock was used. This required two different settings for the day and for the night, or one clock each for the day and the night. For the latter, the speed of the verge escapement (Waag) was changed, for example, in 26 steps (i.e., half the numerical value of 52 weeks). In the weeks of the equinox, both clocks could be operated with the middle weight position on the balance.
See also
Twilight
Terminator (solar)
(in German)
Time perception
Civil time
equinoctial hours
Danna
Julian day
Chronobiology
Bibliography
Karlheinz Deußer: Temporaluhren: Die Suche nach mechanischen Uhren, die mit Temporalstunden liefen. In: Jahresschrift der deutschen Gesellschaft für Chronometrie. Band 51, 2012, S. 143–160.
Jürgen Osing: Hieratische Papyri aus Tebtunis I (Carsten Niebuhr Institute of Ancient Eastern Studies Copenhagen). Museum Tusculanum Press, Copenhagen 1998, ISBN 8-7728-9280-3.
Rudolf Wendorff: Zeit und Kultur. Geschichte des Zeitbewusstseins in Europa. Westdeutscher Vlg, Wiesbaden 1980, ISBN 3-531-11515-4.
References
External links
Die Temporalstunden
Jewish law
Timekeeping
Pages with unreviewed translations
History of timekeeping | Unequal hours | [
"Physics"
] | 890 | [
"Spacetime",
"Timekeeping",
"Physical quantities",
"Time"
] |
53,506,646 | https://en.wikipedia.org/wiki/Dishwasher%20detergent | Dishwasher detergent is a detergent made for washing dishes in a dishwasher. Dishwasher detergent is different from dishwashing liquid made to wash dishes by hand.
Uses
When using a dishwasher, the user must select a special detergent for its use. All detergents are designed for use after the user scrapes leftover food from the dishes before washing. To function, the user places dishes in the dishwasher in such fashion that the surface of all dishes is open to the flow of water.
Most dishwasher detergents are incompatible for use with silver, brass, cast iron, bronze, aluminum, pewter, and goldleaf. They can also harm disposable plastic, anything wood, knives with hollow handles, and fine glassware.
Types
There are specific examples of chemical reactions we use in our everyday lives. For example, a dishwasher detergent uses sodium hypochlorite and sodium carbonate (simple bleach) in a chemical reaction to clean the dishes. Dishes washed in cold water are less clean than dishes washed in hot water.
Composition
Different kinds of dishwashing detergent contain different combinations of ingredients. Common ingredients include:
Phosphates: Bind calcium and magnesium ions to prevent 'hard-water' type limescale deposits. They can cause ecological damage, and have been partially banned or phased out.
Oxygen-based bleaching agents (older-style powders and liquids contain chlorine-based bleaching agents): Break up and bleach organic deposits.
Non-ionic surfactants: Lower the surface tension of the water, emulsifies oil, lipid and fat food deposits, prevents droplet spotting on drying.
Alkaline salts: These are a primary component in older and original-style dishwasher detergent powders. Highly alkaline salts attack and dissolve grease, but are extremely corrosive (fatal) if swallowed. Salts used may include metasilicates, alkali metal hydroxides, sodium carbonate etc.
Enzymes: Break up protein-based food deposits, and possibly oil, lipid and fat deposits. The enzymes used are similar to the ones used in laundry.
Anti-corrosion agent(s): Often sodium silicate, this prevents corrosion of dishwasher components.
Dishwashing detergent may also contain:
Anti-foaming agents: Foam interferes with the washing action. Foam may affect operation of the machine's water-level sensors and will leak past the door seals.
Additives to slow down the removal of glaze & patterns from glazed ceramics
Perfumes
Anti-caking agents (in granular detergent)
Starches (in tablet based detergents)
Gelling agents (in liquid/gel based detergents)
Dishwasher detergents are generally strongly alkaline (basic).
Inexpensive powders may contain sand. Such detergents may harm the dishes and the dishwasher. Powdered detergents are more likely to cause fading on china patterns.
Besides older style detergents for dishwashers, biodegradable detergents also exist for dishwashers. These detergents may be more environmentally friendly than conventional detergents.
Hand-washing dish detergent (washing up liquid) creates a large foam of bubbles which will leak from the dishwasher.
Rinse aid
Rinse aid (sometimes called rinse agent) contains surfactants and uses Marangoni stress to prevent droplet formation, so that water drains from the surfaces in thin sheets, rather than forming droplets.
Rinse aid prevents "spotting" on glassware (caused by droplets of water drying and leaving behind dissolved limescale minerals), and improves drying performance as there is less water remaining to be dried, and a thinner sheet of water has a much larger surface area than a droplet of the same volume.
See also
Dishwashing liquid
Cleaning agent
List of cleaning agents
List of cleaning products
Soap
Green cleaning
Washing
References
Detergents
Dishwashing
Cleaning products | Dishwasher detergent | [
"Chemistry",
"Technology"
] | 824 | [
"Cleaning products",
"Products of chemical industry"
] |
53,506,936 | https://en.wikipedia.org/wiki/Leonard%20Benedict%20Loeb | Leonard Benedict Loeb (September 16, 1891 – June 17, 1978) was a Swiss-born American physicist. He was the son of Jacques Loeb a German-born American physiologist and biologist.
Leonard B. Loeb wrote a number of physics books, including Atomic Structure.
References
External links
Archival collections
Leonard B. Loeb student notebooks, 1914-1915, Niels Bohr Library & Archives
1891 births
1978 deaths
Scientists from Zurich
Experimental physicists
University of California, Berkeley faculty
University of Chicago alumni
Fellows of the American Physical Society
Swiss emigrants to the United States | Leonard Benedict Loeb | [
"Physics"
] | 119 | [
"Experimental physics",
"Experimental physicists"
] |
53,507,375 | https://en.wikipedia.org/wiki/Stears%20%28company%29 | Stears is a market intelligence company for investing in Africa, with headquarters in Lagos, Abuja, and London. Initially established as a media publication called Stears Business, the company was founded in 2017 by Preston Ideh, Abdul Abdulrahim, Foluso Ogunlana, and Michael Famoroti, who met at the London School of Economics and Imperial College in the United Kingdom.
Stears has become a provider of subscription-based data collection tools and analysis services for investing in Africa.
Stears has provided bespoke content around specific issues such as market entry, country analysis, and digital economy for international organisations such as the United Nations Development Programme, the Foreign Commonwealth and Development Office, and knowledge workers. This provides data for the work of analysts, portfolio managers, researchers, and economists.
In 2022, Stears raised $3.3 million in funding from MaC Venture Capital, Serena Ventures (the investment firm of retired tennis star Serena Williams), Melo 7 Tech Partners, Omidyar Group's Laminate Fund and Cascador.
References
Data
Data and information organizations
Nigerian websites | Stears (company) | [
"Technology"
] | 225 | [
"Information technology",
"Data",
"Data and information organizations"
] |
53,508,070 | https://en.wikipedia.org/wiki/CodePen | CodePen is an online community for testing and showcasing user-created HTML, CSS and JavaScript code snippets. It functions as an online code editor and open-source learning environment, where developers can create code snippets, called "pens," and test them. It was founded in 2012 by full-stack developers Alex Vazquez and Tim Sabat and front-end designer Chris Coyier. Its employees work remotely, rarely all meeting together in person. CodePen is a large community for web designers and developers to showcase their coding skills, with an estimated 330,000 registered users and 14.16 million monthly visitors.
References
External links
Computing websites
Web development
Software developer communities
Online integrated development environments | CodePen | [
"Technology",
"Engineering"
] | 147 | [
"Computing websites",
"World Wide Web stubs",
"Web development",
"Software engineering",
"Computing stubs"
] |
53,508,444 | https://en.wikipedia.org/wiki/Hobart%20Hurd%20Willard | Hobart Hurd Willard (June 3, 1881 – May 7, 1974) was an analytical chemist and inorganic chemist who spent most of his career at the University of Michigan. He was known for his teaching skill and his authorship of widely used textbooks. His research interests were wide-ranging and involved the characterization of perchloric acid and periodic acid salts.
Early life and education
Willard was born on June 3, 1881, in Erie, Pennsylvania. His family relocated to Union City, Michigan, in 1883 and he spent the rest of his early life there. His father and later his high school teachers encouraged his interest in chemistry, which he pursued as an undergraduate at the University of Michigan. He received his A.B. in 1903 and his M.A. in 1905. Meanwhile, he was briefly hired as an instructor of chemistry, but at the encouragement of coworkers he decided to pursue his Ph.D. at Harvard University. He received his Ph.D. in 1909 under the supervision of Theodore William Richards.
Academic career
After finishing his Ph.D., Willard returned to Michigan to rejoin the faculty; he became a full professor in 1922 and retired from the university, assuming professor emeritus status, in 1951. He was designated the Henry Russel Lecturer in 1948, noted as the university's highest distinction. He was known for his strong teaching skills and continued teaching at a variety of institutions after his retirement.
During his tenure at Michigan, Willard wrote several widely used and positively reviewed chemistry textbooks and laboratory course manuals, often with former students as coauthors. He also performed consulting work for local industry throughout his career, serving as the Director of the Chemistry and Metallurgy Laboratories for Detroit's Bureau of Aircraft Production in 1917-18 and as a long-term consultant for the Parker Rust-Proof Company.
Willard served as a director of the American Chemical Society from 1934 to 1940 and received the ACS' Fisher Award in Analytical Chemistry in 1951. He was the inaugural recipient of the Anachem Award given by the Association of Analytical Chemists in 1953.
Research
Willard's research interests focused on analytical chemistry and quantitative analysis of inorganic substances. With student G. Frederick Smith, he was particularly productive in studying perchloric acid and periodic acid salts. In addition, he is credited with important work in determining precise atomic weights of chemical elements such as lithium, silver, and antimony, and with development of metal alloy techniques.
Personal life
Willard and his wife Margaret had two daughters, Ann and Nancy. Willard was a photography enthusiast and hobbyist who occasionally sold his work. He died in Ann Arbor, Michigan, on May 7, 1974. Michigan holds a named professorship in his honor; the current Willard Professor of Chemistry is Robert T. Kennedy.
References
Analytical chemists
University of Michigan alumni
Harvard University alumni
University of Michigan faculty
1881 births
1974 deaths
People from Erie, Pennsylvania
People from Union City, Michigan | Hobart Hurd Willard | [
"Chemistry"
] | 586 | [
"Analytical chemists"
] |
53,510,000 | https://en.wikipedia.org/wiki/Diseases%20of%20abnormal%20polymerization | Diseases of abnormal polymerization, or simply DAPs, are a class of disorders characterized by a novel alteration in base unit proteins that results in a structure with pathogenic potential. This functional alteration in a protein in relation to its thermodynamic and kinetic properties enacts an extended chain response among neighboring proteins until an extensive and potentially harmful polymerized structure is formed. Due to this endogenous foreign formation, these diseases are often untreatable and very severe in clinical manifestation. Although DAPs are rare infections, the poor outcome in patients and the need for further understanding makes this class of diseases a pillar for future research.
Replication by recruitment
Diseases of abnormal polymerization are said to undergo "replication", or rather that the number of proteins that are polymerized is shown to generally increase much like in a natural course of infection. Since the functional "pathogens" of DAPs are protein units the diseases are almost entirely independent from the use of nucleic acids. Multiple models illustrating this recruitment function exist, including the PrP protein in prion disease. The PrP protein is the major agent in spongiform encephalopathies and undergoes a clear process of polymerization based upon the natural balancing of thermodynamic states and kinetic summation. Like most proteins PrP can exist in two forms, one major and one minor, an alpha helix structure and a beta-pleated sheet structure respectively, that are balanced during nearly all conditions, but with dominance granted to the stable helix form. In certain instances, it may be possible for two beta forms to contact each other at the same time, and in this case the pair can form bonds that successfully stabilize the beta forms thermodynamically and allowing these structures to remain. This is termed the "seed" of polymerization as from this point the continued interaction, or recruitment, amongst the beta forms is increased perpetually, since there is a constant presence of stable beta forms, as well as the fact that beta forms, or beta-pleated sheets, have a greater number of reactive nucleation sites. This progression forms extended fibrils slowly over time that will then cause localized cytopathology, resulting in the characteristic sites of cell degradation or "sponginess". This general template of recruitment is also characteristic in the condition sickle cell anemia in which the red blood cells are misshapen because of the formation of extended polymer fibrils.
Scenarios for pathogenesis
Spontaneous development
ADPs can be generated in a spontaneous nature by the existence of multiple thermodynamic states and the kinetic equilibrium between the alpha helix and beta-pleated sheets polymerizing into extended fibrils.
Genetic predisposition
In certain ADPs, such as Gerstmann-Straussler or fatal familial insomnia, individuals naturally encode a form of the PrP protein that shifts the equilibrium slightly to make the beta form more favorable, thus increasing the likelihood of additional nucleation and extended polymerization.
Infectious etiology
Many ADPs, including Creutzfeldt-Jakob disease and Kuru, have an infectious nature and can be transmitted to other hosts through various means. In the case of Kuru, familial and cultural rituals in indigenous peoples of Papua New Guinea promoted the consumption of a relative's body upon death, and if contaminated, resulting in the transmission of the original "seed" of polymerization.
Examples
Spongiform encephalopathies Prion Disease (Kuru, CJD, GSS, BSE)
Alzheimer's disease
Sickle cell anemia
Parkinson's disease
Huntington's disease
References
abnormal polymerization of
Polymerization reactions | Diseases of abnormal polymerization | [
"Chemistry",
"Materials_science"
] | 747 | [
"Polymerization reactions",
"Polymer chemistry"
] |
53,510,659 | https://en.wikipedia.org/wiki/Ships%20husbandry | Ships husbandry or ship husbandry is all aspects of maintenance, cleaning, and general upkeep of the hull, rigging, and equipment of a ship. It may also be used to refer to aspects of maintenance which are not specifically covered by the technical departments. The term is used in both naval and merchant shipping, but naval vessel husbandry may also be used for specific reference to naval vessels.
Etymology
Ships husbandry diving
Underwater ships husbandry can be financially advantageous when it eliminates the need for dry-dock repairs or extends the interval between dry-dockings, and reduces the time a ship is required to stay in dry-dock.
Underwater ship husbandry includes the following operations, usually done by commercial divers, though some can be done by ROVs or robotic machinery:
Underwater hull cleaning to remove fouling organisms which increase drag, and therefore reduce top speed and increase fuel consumption. Such cleaning may be of the entire hull or parts thereof, particularly propellers, shafts and thrusters. The underwater hull may be inspected prior to cleaning, and the amount of cleaning done may depend on the inspection results. Hull cleaning may be done by divers using hand held or self-propelled mechanical brushing equipment, water jets or scrapers.
Non-destructive testing and inspection including fouling surveys, inspection of known or suspected damage to structure, equipment or coatings, and inspection of repairs. Several methods may be used, including visual inspection, video recording and magnetic particle testing.
Underwater painting is done to repair paintwork after repairs, or where small areas of paint have been damaged or have worn out. Suitable paints are applied by the diver using brush or roller.
Fiberglass repair, can be hull repair or propeller shaft protective coating repair. Repair of fibreglass shaft coating is generally done in a dry habitat mounted over the shaft, allowing access through the open bottom for the divers. The shaft is first cleaned before wrapping with a new layer of sheathing.
Underwater welding is either done in a submerged dry habitat or wet. Better quality welds can be achieved in dry conditions as the cooling rate is reduced and there is less problem with hydrogen embrittlement. Weld surfaces are prepared by cleaning with scrapers, chipping hammers or hand-held brushes, and pneumatic or hydraulic grinding tools.
Minor repairs to the rubber coating of sonar domes can be done by divers. This entails removal of damaged rubber, preparation of the surface and application of a rubber patch using a suitable adhesive.
Environmental impact
Several of the operations classified as ship husbandry will release some quantity of harmful material into the water, particularly hull cleaning operations which will release antifouling toxins. Underwater ship husbandry can cause an adverse environmental effect as significant amounts of copper and zinc are released by underwater hull scrubbing. Alien biofouling organisms may also be released during this process.
Diving under the hull
The underside of the hull is an overhead environment with no direct vertical access to the surface. As such it constitutes an entrapment hazard, particularly under large vessels where it may be too dark due to low natural light or turbid water to see the way to the side of the hull. The bottom of the largest ships is mostly flat and featureless, exacerbating the problem. Only surface-supplied diving is authorised for this work in most jurisdictions, as this not only secures the diver's breathing gas supply, but also provides a guideline to the exit point. The use of mechanised bottom scrubbing devices which are steered along the hull surface by a diver and scrub it with rotary brushes has been linked with high release of environmental toxins. There is also a hazard of crushing if the clearance is small and the tide range is large.
References
Shipbuilding | Ships husbandry | [
"Engineering"
] | 757 | [
"Shipbuilding",
"Marine engineering"
] |
53,511,508 | https://en.wikipedia.org/wiki/International%20Beacon%20Project | The International Beacon Project (IBP) is a worldwide network of radio propagation beacons. It consists of 18 continuous wave (CW) beacons operating on five designated frequencies in the high frequency band. The IBP beacons provide a means of assessing the prevailing ionospheric signal propagation characteristics to both amateur and commercial high frequency radio users.
The project is coordinated by the Northern California DX Foundation (NCDXF) and the International Amateur Radio Union (IARU). The first beacon of the IBP started operations from Northern California in 1979. The network was expanded to include 8 and subsequently 18 international transmission sites.
History
The first beacon was put into operation in 1979 using the call sign . It transmitted a 1 minute-long beacon every 10 minutes on 14.1 MHz using custom built transmitter and controller hardware. The signal consisted of the beacon's call sign transmitted in Morse code at 100 watts, four 9 second long dashes, each at 100 watts, 10 watts, 1 watt, and 0.1 watt, followed by sign-out at 100 watts.
Northern California DX Foundation and seven partnering organizations from the United States, Finland, Portugal, Israel, Japan, and Argentina operated the first iteration of the beacon network. Due to difficulties encountered in building beacon hardware, each site used a Kenwood TS-120 transceiver keyed and controlled by a custom built beacon controller. The network operated on 14.1 MHz and the beacon format remained unchanged.
In 1995, work began to improve the existing beacon network, so it could operate on 5 designated frequencies on the high frequency band. The new beacon network used Kenwood TS-50 transceivers keyed and controlled by an upgraded beacon controller unit. The number of partner organizations were expanded to 18 and the new 10 second beacon format was adopted.
Notable Projects
Beyond helping amateur radio operators better understand HF radio propagation the project has aided scientists in better understanding the earths ionosphere,
improved prediction models,
and aided in radio direction finding.
Frequencies and transmission schedule
The beacons transmit around the clock on the frequencies
14.100 MHz
18.110 MHz
21.150 MHz
24.930 MHz
28.200 MHz
Each beacon transmits its signal once on each frequency, in sequence from low (14.100 MHz) to high (28.200 MHz), followed by a 130 second pause during which beacons at other sites transmit in turn on the same frequencies, after which the cycle repeats. Each transmission is 10 second-long, and consists of the call sign of the beacon transmitted at 22 words per minute () followed by four dashes. The call sign and the first dash is transmitted at 100 watts of power. Subsequent three dashes are transmitted at 10 watts, 1 watt, and 0.1 watt respectively.
All beacon transmissions are coordinated using GPS time. As such, at a given frequency, all 18 beacons transmit in succession once every 3 minutes.
Hardware
Beacons transmit using commercial HF transceivers (Kenwood TS-50 or Icom IC-7200) keyed and coordinated by a purpose-built, hardware beacon controller.
Beacons
The International Beacon Project operates the following beacons as of January 2024.
{| class="wikitable"
!
! Beacon region
! Call sign
! Transmit site
! Gridsquare
! Operator
|-
|style="text-align:center;"| 1
| United Nationsheadquarters
|
| New York City
|style="text-align:left;"|
| United Nations Staff Recreation CouncilAmateur Radio Club (UNRC)
|-
|style="text-align:center;"| 2
| northernCanada
| VE8AT
| Inuvik, NT
|style="text-align:left;"| CP 38 gh
| RAC/NARC
|-
|style="text-align:center;"| 3
| California,United States
|
| Mt. Umunhum
|style="text-align:left;"|
| Northern California DX Foundation (NCDXF)
|-
|style="text-align:center;"| 4
| Hawaii,United States
|
| Maui
|style="text-align:left;"|
| Maui Amateur Radio Club (Maui ARC)
|-
|style="text-align:center;"| 5
| New Zealand
|
| Masterton
|style="text-align:left;"|
| New Zealand Association of Radio Transmitters (NZART)
|-
|style="text-align:center;"| 6
| Western Australia
|
| Roleystone
|style="text-align:left;"|
| Wireless Institute of Australia (WIA)
|-
|style="text-align:center;"| 7
| Honshū, Japan
|
| Mt. Asama
|style="text-align:left;"|
| Japan Amateur Radio League (JARL)
|-
|style="text-align:center;"| 8
| Siberia, Russia
|
| Novosibirsk
|style="text-align:left;"|
| Russian Amateur Radio Union (SRR)
|-
|style="text-align:center;"| 9
| Hong Kong
|
| Hong Kong
|style="text-align:left;"|
| Hong Kong Amateur Radio Transmitting Society (HARTS)
|-
|style="text-align:center;"| 10
| Sri Lanka
|
| Colombo
|style="text-align:left;"|
| Radio Society of Sri Lanka (RSSL)
|-
|style="text-align:center;"| 11
| South Africa
|
| Pretoria
|style="text-align:left;"|
| South Africa Radio Society (SARL)
|-
|style="text-align:center;"| 12
| Kenya
|
| Kariobangi
|style="text-align:left;"|
| Amateur Radio Society of Kenya (ARSK)
|-
|style="text-align:center;"| 13
| Israel
|
| Tel Aviv
|style="text-align:left;"|
| Israel Amateur Radio Club (IARC)
|-
|style="text-align:center;"| 14
| Finland
|
| Lohja
|style="text-align:left;"|
| Finnish Amateur Radio League (SRAL)
|-
|style="text-align:center;"| 15
| Madeira Island,Portugal
|
| Santo da Serra
|style="text-align:left;"|
| Rede dos Emissores Portugueses (REP)
|-
|style="text-align:center;"| 16
| Argentina
|
| Buenos Aires
|style="text-align:left;"|
| Radio Club Argentino (RCA)
|-
|style="text-align:center;"| 17
| Peru
|
| Lima
|style="text-align:left;"|
| Radio Club Peruano (RCP)
|-
|style="text-align:center;"| 18
| northern Venezuela
|
| Caracas
|style="text-align:left;"|
| Radio Club Venezolano (RCV)
|}
References
Radio frequency propagation
Beacons | International Beacon Project | [
"Physics"
] | 1,501 | [
"Physical phenomena",
"Spectrum (physical sciences)",
"Radio frequency propagation",
"Electromagnetic spectrum",
"Waves"
] |
53,512,240 | https://en.wikipedia.org/wiki/Zygacine | Zygacine is a steroidal alkaloid of the genera Toxicoscordion, Zigadenus, Stenanthium and Anticlea of the family Melanthiaceae. These plants are commonly known and generally referred to as death camas. Death camas is prevalent throughout North America and is frequently the source of poisoning for outdoor enthusiasts and livestock due to its resemblance to other edible plants such as the wild onion. Despite this resemblance, the death camas plant lacks the distinct onion odor and is bitter to taste.
The effects of zygacine consumption are lethal. Symptoms in humans include nausea, vomiting, slowed heart rate, low blood pressure and ataxia. Poisoned animals suffer from loss of appetite, lack of coordination, digestive and excretory disorders, labored breathing, racing heartbeat and frequently death.
Suggested treatment of poisoning in humans include administering dopamine and atropine to the patient. For animals, treatment consists of atropine, picrotoxin and activated charcoal.
History
Scientists first attempted to determine the toxic ingredient(s) of alkaloid extracts of Zygadenus plants in 1913. They were able to isolate zygadenine, the alkamine present in alkaloids of the genus Zigadenus. The minimal pharmacological activity of zygadenine led to subsequent investigations of Zygadenus venenosus and Zygadenus paniculatus which revealed that zygacine was one of the primary toxic components. Although it was first isolated in 1913, the structure and configuration of zygacine weren't reported until 1959.
Zygacine poisoning via ingestion of death camas had been reported in both livestock and humans as early as the nineteenth century. It has been for many years - and continues to be - responsible for the poisonings and deaths of many types of livestock including sheep, cattle, horses, pigs and fowl. A one-time loss of 500 sheep was reported in 1964 and in 1987, 250 sheep died from death camas poisoning. Poisonings generally occur in the early spring when the death camas plant is most abundant and other food sources for livestock are limited. Sheep seem to be poisoned most often due to their grazing behavior as they pull up and consume the entire plant. Moist conditions are more conducive to cattle poisoning as it makes it easier to extract the plant from the soil. Humans have also fallen victim to zygacine poisoning by mistaking the death camas for other edible plants. In 1994, a man presented to the emergency department with gastrointestinal symptoms, a depressed heart rate and low blood pressure after inadvertently eating plant material derived from a species of Zigadenus. He recovered after being treated.
Toxicity
Zygacine is a highly potent compound with an of 2.0 +/- 0.2 mg/kg when administered intravenously and 132 +/- 21 mg/kg when administered orally to mice. The lethal dose conversions for a 60 kg human, 600 kg cow and 80 kg sheep are included in the table below.
General symptoms of zygacine poisoning among humans and animals alike include but are not limited to gastrointestinal and cardiovascular ailments such as nausea, vomiting, diarrhea and irregular heartbeat.
Within an hour of ingesting the toxic death camas plant, a human will begin to experience nausea, vomiting, abdominal cramping and diarrhea. Other symptoms include low heart rate and blood pressure as well as ataxia and muscle spasms.
Initial signs of zygacine poisoning in animals include frothy salivation around the mouth, followed by nausea and vomiting. Severely poisoned animals will suffer from a loss in appetite, lack of coordination and depression. Sheep, in particular, will stand with their heads and ears dropped with their backs are arched. Intestinal peristalsis, a condition characterized by involuntary movement of the muscles in the digestive tract, results in frequent defecation and urination. Fatally poisoned animals develop a weak and rapid pulse and labored breathing. The shuddering struggle to breathe may be confused with convulsions.
Mechanism
Zygacine is a steroidal alkaloid of the veratrum type. Veratrum alkaloid compounds act by attaching to voltage-gated sodium ion channels, altering their permeability. Veratrum alkaloids cause affected sodium channels to reactivate 1000x slower than unaffected channels. They also block inactivation of sodium channels and change their activation threshold so they remain open even at resting potential. As a result, sodium concentrations within the cell rise, leading to increased nerve and muscle excitability. This biochemical activity causes muscle contractions, repetitive firing of the nerves and an irregular heart rhythm from stimulation of vagal nerves which control the parasympathetic functions of the heart, lungs and digestive tract.
Treatment
There is no antidote for zygacine poisoning so only the symptoms arising from poisoning in humans are usually treated, of which bradycardia and hypotension are prioritized. These symptoms are initially treated with atropine, a muscarinic receptor antagonist. In a case study in which atropine was not sufficient, hypotension and bradycardia were successfully treated using dopamine. Dopamine increases renal sodium excretion, blood pressure and the heart rate.
For animals, reported effective treatment of zygacine poisoning consists of injection of 2 mg of atropine sulfate and 8 mg of picrotoxin per 45 kg of body weight. Intravenous fluid therapy is used to increase blood pressure. A stomach tube can be used to relieve stomach pressure in bloated animals.
References
Steroidal alkaloids
Toxins
Plant toxins
Heterocyclic compounds with 6 rings
Nitrogen heterocycles | Zygacine | [
"Chemistry",
"Environmental_science"
] | 1,203 | [
"Toxicology",
"Chemical ecology",
"Steroidal alkaloids",
"Plant toxins",
"Alkaloids by chemical classification",
"Toxins"
] |
53,512,425 | https://en.wikipedia.org/wiki/Jussi%20Pekka%20Kasurinen | Jussi Pekka Kasurinen (born 24 April 1982) is a Finnish non-fiction writer and a post-doctoral scholar, born in Savonlinna, Finland, in 1982.
Academic career
He graduated as a master of science (in engineering) from Lappeenranta University of Technology (LUT) in 2007 and finished his PhD in 2011, also in LUT.
Awards received in academia
Jussi Kasurinen has received the best paper award in the Computer Systems and Technologies conference in 2016 with his paper "Games as Software – Similarities and Differences between the Implementation Projects".
Non-academic career
Kasurinen has also utilized his knowledge gained in academia to popularize science as a writer. He has written several books and articles in IT magazines, such as Skrolli. Kasurinen uses his full name when writing books so that he would not be confused with another Jussi Kasurinen who is also a writer.
List of books Kasurinen has written
Kasurinen, Jussi. Outoa ohjelmointia (Weird programming), publisher Docendo Oy, 192 pages, 2016,
Kasurinen, Jussi. Ohjelmistotestauksen käsikirja (Guidebook to Software Testing), publisher Docendo Oy, 240 pages, 2013.
Kasurinen, Jussi. Ruby on Rails-ohjelmointi (Programming with Ruby on Rails), publisher Docendo/WSOYPro Oy, 260 pages, 2011.
Kasurinen, Jussi. Python 3-ohjelmointi (Introduction to Python 3 Programming), publisher Docendo/WSOYPro Oy, 255 pages, 2009.
Kasurinen, Jussi. Python 3 programming (e-book), 180 pages, 2010. Published by Viope Oy as a part of Python 3 programming course. Available at Viope web store.
Python – ohjelmointiopas (Python – programming manual), Lappeenranta University of Technology, 167 pages, 2007.
Other career events
Kasurinen is credited as actor in Iron Sky: Coming Race and producer in the 2016 short film Infirmity.
Kasurinen is a member of Finnish Software Measurement Association (FiSMA), working as a board member and chairman of the research forum.
Kasurinen has Bacon-Erdos-index of 8.
References
1982 births
Living people
Academic staff of Lappeenranta University of Technology
People in information technology
Finnish writers
Finnish scientists
LUT University alumni | Jussi Pekka Kasurinen | [
"Technology"
] | 516 | [
"People in information technology",
"Information technology"
] |
53,513,088 | https://en.wikipedia.org/wiki/Decarbamoylsaxitoxin | Decarbamoylsaxitoxin, abbreviated as dcSTX, is a neurotoxin which is naturally produced in dinoflagellate. DcSTX is one of the many analogues of saxitoxin (STX).
Saxitoxin is a tricyclic alkaloid compound, which has multiple structural related neurotoxins. One of those related neurotoxins is neosaxitoxin (NSTX) in which the nitrogen at position 2 is not bound to a hydrogen, but to a hydroxyl group. Another toxic analogue of saxitoxin is gonyautoxin (GTX). The difference between GTX and STX is that on the carbon at position 11, a hydrogensulfate is bound.
Between dcSTX, NSTX and GTX, dcSTX is the one which varies most from saxitoxin. In dcSTX there is a double bond between carbons 2 and 3, while there is a single bond in STX. This also results in that the double-bonded N to carbon number 3 in STX, is a single bound NH2 in dcSTX. Another difference between decarbamoylsaxitoxin and saxitoxin is that the amino-carbonyl-oxy-methyl group at position 1 in STX, is only a CH2OH group in dcSTX.
Even though there are slight differences between all saxitoxin-related compounds, all those saxitoxins are neurotoxins which affect the sodium channels. When in contact with one of the saxitoxins it can cause a severe illness, which is known as paralytic shellfish poisoning (PSP).
Source in nature
From eating shellfish, under which mussels, clams, whelks and scallops, multiple illnesses can result. One of them is sensory and motor paralysis, known as paralytic shellfish poisoning (PSP), which results from ingestion of saxitoxin and its derivatives, such as decarbamoylsaxitoxin. Shellfish can concentrate a dinoflagellate known as Gonyaulax tamarensis, which elaborates saxitoxin. Mussels are known to filter up to 20 litres of water a day, which is why they are very likely to carry the toxin when the surrounding water is contaminated. This dinoflagellate does not affect the shellfish, but when an organism eats the scallop shuckings, it risks getting poisoned. Some species, such as the littleneck clam, possess an enzyme that converts saxitoxin into decarbamoylsaxitoxin, which reportedly decreases the toxicity to humans of the saxitoxins present.
Structure and synthesis
Structure and properties
Synonyms of decarbamoylsaxitoxin are; dcSTX-saxitoxin, decarbamoylsaxitoxin, decarbamylsaxitoxin
Synthesis
Decarbamoylsaxitocin is like saxitoxin a very hygroscopic solid. Since saxitoxins and their derivatives are mainly produced by the Gonyaulax tamarensis dinoflagellate, for a long time the exact synthesis pathway was unknown. Saxitoxin was the first paralytic shellfish toxin for which a total synthesis was described. This was done by Kishi and his research group in 1977. In 1991 they managed to describe the synthesis of decarbamoylsaxitoxin as well.
Metabolism
Decarbamoylsaxitoxin enters the body via the mouth. There it can be absorbed through the mucosa, and later on it can be absorbed through the small intestine. After absorption, the toxin is distributed through the body water. It gets removed by the kidneys and is excreted via urine.
An exact biotransformation of decarbamoylsaxitoxin is not known yet. In 2004, a study on people who died from paralytic shellfish poisoning reported detected oxidation of saxitoxin into neosaxitoxin.
In a more recent study on human liver samples, a metabolic pathway was proposed for saxitoxin which is shown in figure 2. They found that saxitoxin can be converted into neosaxitoxin in the human body, which harmonizes the earlier research. The neosaxitoxin will however be converted further into either a sugar-binding state or into GTX4/GTX1, a pair of gonyautotoxin epimers. These epimers can be converted to a sugar-binding state as well. Also, the sugar-bound state of saxitoxin can be formed. As this study shows, the phase II conjugation reaction is a very common glucoronidation reaction. Due to this, the substance gets more hydrophilic which makes it more easily excretable.
Even though this study was done on saxitoxin exclusively, it is very likely that the metabolic pathway of decarbamoylsaxitoxin will be the same, since the major structural difference between them is the shown OONH2 substituent, indicated with a yellow circle in the figure, which is a hydroxyl substituent in decarbamoylsaxitoxin. This group is not affected in the proposed metabolism and will most likely not interrupt the shown mechanism.
Mechanisms of action
Decarbamoylsaxitoxin is a known neurotoxin, which mechanism is based on that of saxitoxin. Both namely bind to sodium channels, as shown in figure 3 Sodium channels contain negative residues at the top of their pore. These negatively charged residues are part of the filter for sodium. Decarbamoylsaxitoxin contains two guanidine substructures which can be protonated easily. Protonation of the guanidine substructures leads to a positive charge on the decarbamoylsaxitoxin and because of this positive charge the decarbamoylsaxitoxin can bind to the sodium channels. This binding to sodium channels prevents sodium passing through the channel. Because sodium passage is blocked, the channel cannot fulfil its function and it will be impossible to generate an action potential in the cell with the blocked sodium channels.
There has been a study performed on which sodium channels are mainly targeted by the neurotoxin. This study showed that the neuromuscular transmission in the motor axon and the muscular membrane is targeted whereas the end-plate is left unaffected. It also showed that the atrioventicular node is the main target inside the heart. The consequences of decarbamoylsaxitoxin are paralysis and death. In vitro tests declared decarbamoylsaxitoxin more toxic than saxitoxin. It is not clear why this is the case; it can be speculated that it is caused by the alcohol group that is present on decarbamoylsaxitoxin instead of the amide group on saxitoxin. However, what can be concluded for sure is that decarbamoylsaxitoxin is converted into other compounds in the body or has trouble reaching the sodium channels. In vivo tests declared decarbamoylsaxitoxin half as toxic as saxitoxin.
Illness and poisoning
Toxicology
In coastal waters, mostly in temperate and subtropical regions, dinoflagellate blooms can occur when the conditions for growth and aggregation are optimal. They cause so called ‘red tides’ or ‘red waters’ and the concentration of toxic can be of great risk for both marine life and humans. However, also when the water is clear shellfish can contain toxins, which are not destroyed by heating or freezing. In case of a red tide, a mussel can contain as much as 180 g of toxin. To human, a dose of only 1 mg saxitoxin can be fatal. Worldwide the limits for toxins in shellfish which cause paralytic shellfish poisoning is set at 80 μg per 100 g of meat.
Illness in humans
Usually, within minutes of ingestion of the poisoned shellfish, paranesthesia of the oral region and fingertips are noticed. This gradually proceeds to the neck, arms, legs and toes, together with general muscular incoordination. Patients can start feeling numb, due to which it is hard to make voluntary movements. Also symptoms as dizziness, weakness and incoherence can occur. In the final stage of the poisoning, respiratory distress and full muscular paralysis occur, usually between 2 and 12 hours after ingestion.
The symptoms are sometimes difficult to interpret, since they are also associated with drunkenness. Alcohol can increase the severity of symptoms.
Treatment
There is no antidote to paralytic shellfish poisoning. However, with proper medical care, most patients will survive. The most important in treatment is assistance of the patient with ventilation. Also alkaline and sodium-containing fluids can be used to block the effect of paralytic shellfish toxins on nerve conduction.
See also
Saxitoxin
Gonyautoxin
Neosaxitoxin
Paralytic Shellfish Poisoning (PSP)
Sodium channels
References
Marine neurotoxins
Guanidine alkaloids
Voltage-gated sodium channel blockers
Geminal diols | Decarbamoylsaxitoxin | [
"Chemistry"
] | 1,929 | [
"Alkaloids by chemical classification",
"Guanidine alkaloids"
] |
53,513,295 | https://en.wikipedia.org/wiki/Science%20and%20technology%20in%20Pacific%20Island%20countries |
Socio-economic context
Trends
Pacific Island economies are mostly dependent on natural resources, with a tiny manufacturing sector and no heavy industry. In Fiji and Papua New Guinea, for instance, there is a need to adopt automated machinery and design in forestry and to improve training, in order to add value to exports.
Papua New Guinea experienced the strongest economic growth between 2005 and 2013 (60%), during the commodities boom. Even during the global financial and economic crisis of 2008-2009, its economy grew by 13%. Vanuatu saw the next strongest growth (35%) over this period, including 10% growth in 2008-2009. Growth was more pedestrian in the Marshall Islands (a cumulative 19%), Tuvalu (16%), Samoa (15%), Kiribati (13%), Fiji (12%) and Tonga (8%). The economies of the Federated States of Micronesia and Palau actually shrank over this nine-year period. Samoa, the Marshall Islands and Fiji all experienced recession in 2008 and 2009.
The trade balance is more skewed towards imports than exports, with the exception of Papua New Guinea, which has a mining industry. There is growing evidence that Fiji is becoming a re-export hub in the Pacific; between 2009 and 2013, its re-exports grew threefold, accounting for more than half of all exports by Pacific Island states. Samoa can also expect to become more integrated in global markets from now on, having joined the World Trade Organization in 2012. Fiji, Papua New Guinea and the Solomon Islands are also members of the World Trade Organization.
Pacific Island states make up a very small share of the South Pacific's high-tech exports. These exports receded between 2008 and 2013 by 46% for Fiji and by 41% for Samoa, according to the United Nations' Comtrade database. Fiji's high-tech exports were down from US$5.0 million to US$2.7 million and Samoa's from US$0.3 to US$0.2 million.
In 2013, the majority of Fijian high-tech exports were pharmaceutical products (84%), whereas Samoa exports mainly scientific instruments (86%) and Kiribati non-electrical machinery (79%). Armaments make up 92% of high-exports from the Solomon Islands.
Internet access
By 2013, one in three inhabitants of Fiji, Tonga and Tuvalu had Internet access. Growth in Internet access since 2010 has levelled out the disparity between countries to some extent, although connectivity remained extremely low in Vanuatu (11%), the Solomon Islands (8%) and Papua New Guinea (7%) in 2013.
Advances in mobile phone technology have clearly been a factor in the provision of Internet access to remote areas. The flow of knowledge and information through internet is likely to play an important role in the more effective dissemination and application of knowledge across the vast Pacific Island nations.
Mobile Internet penetration was the lowest (18%) of any region in the world in 2018 but this figure is expected to double by 2023. In this remote region, high-speed Internet access comes from laying an expensive undersea cable. Recent links have been created for Papua New Guinea (2020), the Solomon Islands (2020) and Tonga (2018).
Pacific countries are reshaping their social and economic environments to meet digital demands. To benefit from modern digital and other technological tools, regulatory bodies have adopted social media platforms and messaging systems in official protocols to disseminate disaster warnings in Samoa, Tonga, Fiji and Niue, as well as weather forecasts and information on climate change.
In 2015, the Pacific Islands Forum Leaders established an ICT Working Group made up of CROP agencies that is co-ordinated by the University of the South Pacific. However, no regional mechanism has since emerged in this area.
In the Boe Declaration on Regional Security, produced during the 2018 Pacific Islands Forum, Pacific leaders expanded the concept of security to include cybersecurity. Efforts are under way to assess cybersecurity capacity in Polynesia, Melanesia and Micronesia, in tandem with the United Nations International Telecommunication Union and other partners. Samoa has been the first to develop a National Cyber Security Strategy 2016–2021.
Regional initiatives
Regional bodies addressing technological issues
Both the largest and smallest Pacific nations acknowledge that taking a regional approach to science and technology offers them greater opportunities for institutional development. This approach is encapsulated in the Framework for Pacific Regionalism (2014). All 14 nations have mandated the agencies attached to the Council of Regional Organisations of the Pacific (CROP) to conduct technical backstopping. CROP agencies partially fulfill the role that a science council might play in other regions. However, none of these agencies has a specific mandate or policy for science and technology.
Pacific Island states have established a number of regional bodies to address technological issues for sectorial development. Examples are the Council of Regional Organisations of the Pacific, such as the Pacific Community (SPC); Pacific Islands Forum Secretariat; and Secretariat of the Pacific Region Environmental Programme.
The Ministers of Education from Pacific Island countries signed a Ministerial communiqué on Pacific Science, Technology and Innovation in 2017, in which they committed to developing regional and national STI policies and roadmaps. However, no policy or roadmap has since been published for want of resources.
The 2014 Small Island Developing States (SIDS) Accelerated Modalities of Action Pathway (SAMOA Pathway) identified science and technology as being critical to SIDS’ sustainable development.
The need for research is being recognized at the regional level. The Pacific Community Centre for Ocean Science was established in New Caledonia in 2015, hosted by SPC. Construction of the Pacific Climate Change Centre was completed in Apia, Samoa in 2019 (see below).
Pacific–Europe Network for Science, Technology and Innovation
The establishment of the Pacific–Europe Network for Science, Technology and Innovation (PACE-Net Plus) goes some way towards filling the void in science policy, at least temporarily. Funded by the European Commission within its Seventh Framework Programme for Research and Innovation (2007–2013), this project has spanned the period 2013–2016 and thus overlaps with the European Union’s Horizon 2020 programme.
The objectives of PACE–Net Plus are to reinforce the dialogue between the Pacific region and Europe in science, technology and innovation; to support biregional research and innovation through calls for research proposals; and to promote scientific excellence and industrial and economic competition. Ten of its 16 members come from the Pacific region and the remainder from Europe.
The Pacific partners are the Australian National University, Montroix Pty Ltd (Australia), University of the South Pacific, Institut Malardé in French Caledonia, National Centre for Technological Research into Nickel and its Environment in New Caledonia, South Pacific Community, Landcare Research Ltd in New Zealand, University of Papua New Guinea, Samoa National University and the Vanuatu Cultural Centre.
The other six partners are: the Association of Commonwealth Universities, the Institut de recherche pour le développement in France, the Technical Centre for Agricultural and Rural Cooperation, a joint international institution of the African, Caribbean and Pacific Group of States and the European Union, the Sociedade Portuguesa de Inovação, United Nations Industrial Development Organization and Leibniz Centre for Tropical Marine Ecology in Germany.
PACE-Net Plus focuses on three societal challenges:
Health, demographic change and well-being;
Food security, sustainable agriculture, marine and maritime research and the bio-economy; and
Climate action, resource efficiency and raw materials.
PACE–Net Plus has organized a series of high-level policy dialogue platforms alternately in the Pacific region and in Brussels, the headquarters of the European Commission. These platforms bring together key government and institutional stakeholders in both regions, around STI issues.
A conference held in Suva (Fiji) in 2012 under the umbrella of PACE–Net Plus produced recommendations for a strategic plan for research, innovation and development in the Pacific. The conference report published in 2013 identified R&D needs in the Pacific in seven areas:
health;
agriculture and forestry;
fisheries and aquaculture;
biodiversity and ecosystem management;
freshwater;
natural hazards; and
energy.
Pacific Islands University Research Network
Noting the general absence of regional and national policies and plans for science, technology and innovation in the Pacific, the PACE–Net Plus conference established the Pacific Islands University Research Network to support intra- and inter- regional knowledge creation and sharing and to prepare succinct recommendations for the development of a regional policy framework for science, technology and innovation.
This formal research network will complement the Fiji-based University of the South Pacific, which has campuses in other Pacific Island countries.
Importance of data to inform policy
It was intended for the policy role of the Pacific Islands University Research Network to be informed by evidence gleaned from measuring capability in science, technology and innovation but the absence of data presents a formidable barrier. As of 2015, only Fiji had recent data on expenditure on research and development (R&D) and there were no recent data on researchers and technicians for any of the developing Pacific island countries.
Without relevant data, it will be difficult for developing Pacific Island states to monitor their progress towards Sustainable Development target 9.5, namely: Enhance scientific research, upgrade the technological capabilities of industrial sectors in all countries, in particular developing countries, including, by 2030, encouraging innovation and substantially increasing the number of research and development workers per 1 million people and public and private research and development spending. The two indicators chosen by the United Nations to measure progress are research and development expenditure as a proportion of GDP (9.5.1) and Researchers (in full-time equivalent) per million inhabitants (9.5.2).
Efforts to collate and co-ordinate regional and national data are growing. Such efforts include the PRISM database from the SPC Statistics for Development Division and the national and regional environmental data portals created by countries with the support of the Inform Project.
National policy issues
Fiji
Higher education
Fiji, Papua New Guinea and Samoa all consider education to be one of the key policy tools for driving science, technology and innovation, as well as modernization. Fiji, in particular, has made a supreme effort to re-visit existing policies, rules and regulations in this sector. The Fijian government allocates a larger portion of its national budget to education than any other Pacific Island country (4.2% of GDP in 2011), although this is down from 6% of GDP in 2000. The proportion of the education budget allocated to higher education (0.5% of GDP) amounts to 13% of the public education budget. Scholarship schemes like National Toppers, introduced in 2014, and the availability of student loans have made higher education attractive and rewarding in Fiji.
According to an internal investigation into the choice of disciplines in school-leaving examinations (year 13), Fijian students have shown a greater interest in science since 2011. A similar trend can be observed in enrolment figures at all three Fijian universities.
Many Pacific Island countries take Fiji as a benchmark for education. The country draws education leaders from other Pacific Island countries for training and, according to the Ministry of Education, teachers from Fiji are in great demand in these countries.
One important initiative has been the creation of the Higher Education Commission (FHEC) in 2010, the regulatory body in charge of tertiary education in Fiji. FHEC has embarked on registration and accreditation processes for tertiary-level education providers to improve the quality of higher education in Fiji. In 2014, FHEC allocated research grants to universities with a view to enhancing the research culture among faculty.
Research and development
Fiji is the only developing Pacific Island country with recent data for gross domestic expenditure on research and development (GERD). The national Bureau of Statistics cites a GERD/GDP ratio of 0.15% in 2012. Private-sector research and development (R&D) is negligible. Between 2007 and 2012, government investment in R&D tended to favour agriculture. Scientists publish much more in geosciences and medical sciences than in agricultural sciences, however.
Agriculture
Food security has been given high priority in the Fiji 2020 Agriculture Sector Policy, as part of a shift from subsistence to commercial agriculture and agro-processing. Strategies outlined in Fiji 2020 include:
modernizing agriculture in Fiji;
developing integrated systems for agriculture;
improving delivery of agricultural support systems;
enhancing innovative agricultural business models; and
strengthening the capacity for policy formulation.
Fiji has taken the initiative of shifting away from subsistence agriculture towards commercial agriculture and agro-processing of root crops, tropical fruits, vegetables, spices, horticulture and livestock. In 2013, the Ministry of Agriculture revived Fiji’s Agricultural Journal in 2013, which had been dormant for 17 years.
In 2007, agriculture and primary production accounted for just under half of government expenditure on R&D, according to the Fijian National Bureau of Statistics. By 2012, this had risen to almost 60%. Scientists publish much more in the field of geosciences than in agriculture, though. Between 2008 and 2014, agriculture accounted for only 11 out of Fiji's 460 articles catalogued in Thomson Reuters' Web of Science (Science Citation Index Expanded), compared to 85 articles in geosciences.
The rise in government spending on agricultural research has come to the detriment of research in education, which dropped to 35% of total research spending between 2007 and 2012. Government expenditure on health has remained fairly constant, at about 5% of the total for research, according to the Fijian National Bureau of Statistics.
Health
Over the six years to 2012, government expenditure on health remained fairly constant but low in Fiji, at about 5% of the total for research, according to the Fijian National Bureau of Statistics. This may explain why medical sciences accounted for only 72 out of Fiji's 460 articles catalogued in Thomson Reuters' Web of Science (Science Citation Index Expanded) between 2008 and 2014.
The Fijian Ministry of Health is seeking to develop endogenous research capacity through the Fiji Journal of Public Health, which it launched in 2012. A new set of guidelines are now in place to help build endogenous capacity in health research through training and access to new technology. The new policy guidelines require that all research projects initiated in Fiji with external bodies demonstrate how the project will contribute to local capacity-building in health research.
Fisheries
The desire to ensure that fisheries remain sustainable is fuelling the drive to use science and technology to make the transition to value-added production. The fisheries sector in Fiji is currently dominated by the catch of tuna for the Japanese market. The Fijian government plans to diversify this sector through aquaculture, inshore fisheries and offshore fish products such as sunfish and deep-water snapper. Accordingly, many incentives and concessions are being offered to encourage the private sector to invest in these areas.
ICT sector
Fiji has shown substantial growth in access to Internet and mobile phone services. This trend has been supported by its geographical location, service culture, pro-business policies, English-speaking population and well-connected e-society. Relative to many other South Pacific Islands, Fiji has a fairly reliable and efficient telecommunications system with access to the Southern Cross submarine cable linking New Zealand, Australia and North America. A recent move to establish the University of the South Pacific Stathan ICT Park, the Kalabo ICT economic zone and the ATH technology park in Fiji should boost the ICT support service sector in the Pacific region.
Papua New Guinea
Higher education
In its Higher Education Plan III 2014–2023, Papua New Guinea sets out a strategy for transforming tertiary education and R&D through the introduction of a quality assurance system and a programme to overcome its limited R&D capacity.
Research and development
The National Vision 2050 was adopted in 2009. It has led to the establishment of the Research, Science and Technology Council. At its gathering in November 2014, the Council re-emphasized the need to focus on sustainable development through science and technology.
Vision 2050’s medium-term priorities are:
emerging industrial technology for downstream processing;
infrastructure technology for the economic corridors;
knowledge-based technology;
Science and engineering education; and
to reach the target of investing 5% of GDP in R&D by 2050.
By 2016, the share of GDP invested in research and development measured just 0.03%.
Between 2008 and 2014, 82% of scientific articles from Papua New Guinea concerned the biological and medical sciences. Less than 10% of the country's 517 articles catalogued in Thomson Reuters' Web of Science (Science Citation Index Expanded) focused on geosciences.
In 2016, women represented 33.2% of the scientists in Papua New Guinea, on par with the global share.
Professor Teatulohi Matainaho serves as Chief Science Advisor to Papua New Guinea, appointed in 2013.
Sustainable development
Disaster resilience
Countries around the Pacific Rim are seeking ways to link their national knowledge base to regional and global advances in science. One motivation for this greater interconnectedness is the region’s vulnerability to geohazards such as earthquakes and tsunamis – the Pacific Rim is not known as the Ring of Fire for nothing. In 2009, Samoa suffered a submarine earthquake of a magnitude of 8.1 on the Richter Scale, the strongest earthquake recorded that year. The subsequent tsunami caused substantial damage and loss of life in Samoa, American Samoa, and Tonga.
The need for greater disaster resilience is inciting countries to develop collaboration in the geosciences.
Climate change
Climate change is a parallel concern, as the Pacific Rim is also one of the most vulnerable regions to rising sea levels and increasingly capricious weather patterns. In March 2015, for instance, much of Vanuatu was flattened by Cyclone Pam.
Climate change seems to be the most pressing environmental issue for Pacific Island countries, as it is already affecting almost all socio-economic sectors. The consequences of climate change can be seen in agriculture, food security, forestry and even in the spread of communicable diseases. Climate change mostly concerns marine issues, such as the growing frequency and severity of storms, rising sea levels and the increased salinity of soils and groundwater.
The Secretariat of the Pacific Community has initiated several activities to tackle problems associated with climate change. These cover a great variety of areas, including fisheries, freshwater, agriculture, coastal zone management, disaster management, energy, traditional knowledge, education, forestry, communication, tourism, culture, health, weather, gender implications and biodiversity. Almost all Pacific Island countries are involved in one or more of these activities.
The Seventh Pacific Islands Leaders Meeting with Japan in 2015 pledged to establish a Pacific Climate Change Centre. Construction of the centre was completed in Apia, Samoa, in 2019. A shared regional asset, the centre has four mutually reinforcing functions: knowledge brokerage; applied research; capacity-building; and innovation to promote climate change adaptation and mitigation. The government of Samoa, the Pacific Regional Environment Programme and the Japan International Cooperation Agency are all collaborating to deliver 12 courses for trainees from all Pacific Island countries and territories by 2022. The centre also houses a research node of Australia’s University of Newcastle in partnership with the Pacific Regional Environment Programme; it has offered PhD scholarships since 2018 and hosts an ‘innovation incubator’. Research undertaken at the centre aligns with the four priority areas defined by the Pacific leaders, namely: climate change resilience; ecosystems and biodiversity protection; waste management; and environmental governance.
Pacific Adaptation to Climate Change
The first major scheme focusing on adaptation to climate change and climate variability dates back to 2009. Pacific Adaptation to Climate Change involves 13 Pacific Island nations, with international funding from the Global Environment Facility, as well as from the US and Australian governments.
Secretariat of the Pacific Region Environment Programme
Several projects related to climate change are also being co-ordinated by the United Nations Environment Programme, within the Secretariat of the Pacific Region Environmental Programme (SPREP). The aim of SPREP is to help all members improve their ‘capacity to respond to climate change through policy improvement, implementation of practical adaptation measures, enhancing ecosystem resilience to the impacts of climate change and implementing initiatives aimed at achieving low-carbon development’.
Samoa Pathway
The blueprint for the subregion’s sustainable development over the coming decade is the Samoa Pathway, the action plan adopted by countries at the third United Nations Conference on Small Island Developing States in Apia (Samoa) in September 2014. The Samoa Pathway focuses on, inter alia, sustainable consumption and production; sustainable energy, tourism and transportation; climate change; disaster risk reduction; forests; water and sanitation, food security and nutrition; chemical and waste management; oceans and seas; biodiversity; desertification, land degradation and drought; and health and non-communicable diseases.[1]
Forestry
Forestry is an important economic resource for Fiji and Papua New Guinea. However, forestry in both countries uses low and semi-intensive technological inputs. As a result, product ranges are limited to sawed timber, veneer, plywood, block board, moulding, poles and posts and wood chips. Only a few limited finished products are exported. Lack of automated machinery, coupled with inadequately trained local technical personnel, are some of the obstacles to introducing automated machinery and design. Policy-makers need to turn their attention to eliminating these barriers, in order for forestry to make a more efficient and sustainable contribution to national economic development.
Energy
On average, 10% of the GDP of Pacific Island countries funds imports of petroleum products but in some cases this figure can exceed 30%. In addition to high fuel transport costs, this reliance on fossil fuels leaves Pacific economies vulnerable to volatile global fuel prices and potential spills by oil tankers.
Consequently, many Pacific Island countries are convinced that renewable energy will play a role in their socio-economic development. In Fiji, Papua New Guinea, Samoa and Vanuatu, renewable energy sources already represent significant shares of the total electricity supply: 60%, 66%, 37% and 15% respectively. Tokelau has even become the first country in the world to generate 100% of its electricity using renewable sources.
According to the Secretariat of the Pacific Community, renewable energy still represented less than 10% of total energy use in the 22 Pacific Island countries and territories in 2015. The Secretariat of the Pacific Community observed that, 'while Fiji, Papua New Guinea and Samoa are leading the way with large-scale hydropower projects, there is enormous potential to expand the deployment of other renewable energy options such as solar, wind, geothermal and ocean-based energy sources'.
International development partners are participating in several projects to develop renewable energy in the Pacific island states.
Cook Islands Renewable Energy Chart Implementation Plan
In the Cook Islands, for instance, the Asian Development Bank plans to supply electricity from renewable energy to all inhabited islands by 2020, within the Cook Islands Renewable Energy Chart Implementation Plan for 2012–2020. New solar photovoltaic power plants with lithium-ion batteries were being built on up to six islands of the Southern Group in 2014.
Fiji's Rural Electrification Fund
The Fiji Rural Electrification Fund will bring affordable solar power and battery storage to 300 rural communities that rely on diesel generators or are without electricity access. Initiated in 2018 and lasting ten years, this fund is a public–private partnership.
Vanuatu's National Green Energy Fund
To equip its National Energy Road Map 2016–2030, Vanuatu approved the National Green Energy Fund in 2016 with the goal of mobilising US$ 20 million to provide all households with access to electricity (primarily through individual solar systems) and to improve energy efficiency by 2030. In off-grid areas, households’ access to electricity increased from 9% in 2015 to 64.4% in 2017. The increase was attributed to investments in imported, plug-in solar home systems, supported by the Vanuatu Rural Electrification Project in 2016. However, the share of renewable energy in electricity generation declined from 29% to 18% over the same period, owing in part to a reduction in the use of biofuels in Vanuatu’s largest electricity concession in Port Vila.
Pacific Centre for Renewable Energy and Energy Efficiency
In April 2014, Pacific Ministers for Energy and Transport agreed to establish the Pacific Centre for Renewable Energy and Energy Efficiency, 'a first for the Pacific'. The centre will become part of the United Nations Industrial Development Organization's network of regional Sustainable Energy for All Centres of Excellence, along with centres for the Caribbean Community, Economic Community of West African States, the Southern African Development Community and the East African Community.
The Pacific Centre for Renewable Energy and Energy Efficiency was established in Tonga in 2016 to advise the private sector on related policy matters, provide capacity-building and promote business investment. The centre facilitates a financial mechanism offering competitive grants for start-ups to spur the adoption of renewable energy by the business sector. The centre is part of the Global Network of Regional Sustainable Energy Centres and SIDS DOCK framework designed to attract international investment in the renewable energy sector.
Renewable Energy in Pacific Island Countries Developing Skills and Capacity programme
Efforts are under way to improve countries’ capacity to produce, conserve and use renewable energy. For example, the European Union has funded the Renewable Energy in Pacific Island Countries Developing Skills and Capacity programme (EPIC). Since its inception in 2013, EPIC has developed two master’s programmes in renewable energy management and helped to establish two Centres of Renewable Energy, one at the University of Papua New Guinea and the other at the University of Fiji. Both centres became operational in 2014 and aim to create a regional knowledge hub for the development of renewable energy.
Adapting to Climate Change and Sustainable Energy programme
In February 2014, the European Union and the Pacific Islands Forum Secretariat signed an agreement for a programme on Adapting to Climate Change and Sustainable Energy worth €37.26 million which will benefit 15 Pacific Island states. These are the Cook Islands, Fiji, Kiribati, Marshall Islands, Federated States of Micronesia, Nauru, Niue, Palau, Papua New Guinea, Samoa, Solomon Islands, Timor-Leste, Tonga, Tuvalu and Vanuatu.
Inclusion of traditional knowledge
Limited freedom of expression and, in some cases, religious conservatism discourage research in certain areas but the experience of Pacific Island countries shows that sustainable development and a green economy can benefit from the inclusion of traditional knowledge in formal science and technology, as underlined by the Sustainable Development Brief prepared by the Secretariat of the Pacific Community in 2013.
Renewable energy targets
As part of their Nationally Determined Contributions under the Paris Agreement, the Pacific Island countries are building national renewable energy systems. All 14 countries now have energy strategies, although some extend only to 2020. Nearly all place a strong emphasis on electricity generation using renewable resources.
Scientific output in the region
Trends in scientific authorship
According to the Web of Science, Papua New Guinea had the largest number of publications (110) among Pacific Island states in 2014, followed by Fiji (106). Fijian research was concentrated in a handful of scientific disciplines, such as medical sciences, geosciences and biology. Nine out of ten scientific publications from Papua New Guinea focused on immunology, genetics, biotechnology and microbiology.
This pattern contrasts with the trend observed in the French territories of New Caledonia and French Polynesia, where there was a strong emphasis on geosciences: six to eight times the world average for this field.
Trends in international co-authorship
More than three-quarters of articles published by scientists from Pacific Island nations between 2008 and 2014 were signed by international collaborators, according to Thomson Reuters' Web of Science, Science Citation Index Expanded. International co-authorship was higher for Papua New Guinea and Fiji (90% and 83% respectively) than for New Caledonia and French Polynesia (63% and 56% respectively).
All countries counted North American partners among their top five partners. Fijian research collaboration with North American partners even exceeded that with India, even though a large proportion of Fijians are of Indian origin.
Research partnerships also involved Australia and countries in Europe. Surprisingly, there was little co-authorship with authors based in France, with the notable exception of Vanuatu. Some Pacific Island states counted their neighbours among their closest scientific collaborators, as in the case of the Solomon Islands and Vanuatu.
Many of the smaller Pacific Island states have a near-100% rate of co-authorship This extremely high rate can be a double-edged sword. According to the Fijian Ministry of Health, research collaboration often results in an article being published in a reputed journal but gives very little back in terms of strengthening health in Fiji. A new set of guidelines are now in place in Fiji to help build endogenous capacity in health research through training and access to new technology. The new policy guidelines require that all research projects initiated in Fiji with external bodies demonstrate how the project will contribute to local capacity-building in health research.
Top five foreign collaborators for South Pacific scientists, 2008-2014
Source: UNESCO Science Report: towards 2030 (2015), Figure 27.8. Data from Thomson Reuters' Web of Science, Science Citation Index Expanded, data treatment by Science Metrix
A need to focus on local goals
Countries are struggling to steer their scientific efforts toward sustainable development, at a time when the United Nations’ Sustainable Development Goals have taken over from the Millennium Development Goals in 2016. It has been suggested that countries could begin by encouraging their scientists to focus more on attaining local goals for sustainable development, rather than on publishing in high-profile international journals on topics that may be of lesser local relevance. The difficulty with this course of action is that the key metrics for recognizing scientific quality are publications and citation data. The answer to this dilemma most likely lies in the need to recognize the global nature of many local development problems. 'We are dealing with problems without boundaries and we underestimate the scale and nature of their consequences at our collective peril. As global citizens, the research and policy communities have an obligation to collaborate and deliver, so arguing for national priorities seems irrelevant'.
New scientific journals
In 2012, the Fijian Ministry of Health launched the Fiji Journal of Public Health, in an attempt to develop endogenous research capacity. In parallel, the Ministry of Agriculture revived Fiji’s Agricultural Journal in 2013, which had been dormant for 17 years.
In addition, two regional journals were launched in 2009 as a focus for Pacific scientific research, the Samoan Medical Journal and the Papua New Guinea Journal of Research, Science and Technology.
References
Sources
Science and technology by location | Science and technology in Pacific Island countries | [
"Technology"
] | 6,171 | [
"Science and technology by location"
] |
53,513,426 | https://en.wikipedia.org/wiki/Lie%20group%20integrator | A Lie group integrator is a numerical integration method for differential equations built from coordinate-independent operations such as Lie group actions on a manifold. They have been used for the animation and control of vehicles in computer graphics and control systems/artificial intelligence research.
These tasks are particularly difficult because they feature nonholonomic constraints.
See also
Euler integration
Lie group
Numerical methods for ordinary differential equations
Parallel parking problem
Runge–Kutta methods
Variational integrator
References
Numerical analysis | Lie group integrator | [
"Mathematics"
] | 97 | [
"Applied mathematics",
"Computational mathematics",
"Applied mathematics stubs",
"Mathematical relations",
"Numerical analysis",
"Approximations"
] |
53,513,683 | https://en.wikipedia.org/wiki/NGC%202681 | NGC 2681 is a lenticular galaxy in the constellation Ursa Major. The galaxy lies 50 million light years away from Earth, which means, given its apparent dimensions, that NGC 2681 is approximately 55,000 light years across. NGC 2681 has an active galactic nucleus and it is a type 3 Seyfert galaxy. Its nucleus is also a low-ionization nuclear emission-line region.
NGC 2681 has possibly three bars, with a relatively large bar at the outer side. Because the galaxy is seen nearly face-on, the bar like structures cannot be projection effects. From Earth based observations, in B-I images the galaxy showed neither grand design spirals nor a ring, but only two symmetrical spiral arms starting from the end of the primary bar. In Hα images some HII regions were observed in the spiral arms. A dust spiral is seen in Hubble space telescope images extending to the centre. The lack of stellar gradient in the central regions and the data from Faint Object Camera, Faint Object Spectrograph and International Ultraviolet Explorer indicate that the galaxy had a starburst event approximately one billion years ago, possibly after the tidal interaction with another galaxy, which involved all the galaxy.
Dynamical modeling of the velocity dispersions suggests that NGC 2681 hosts a supermassive black hole whose upper mass limit was set at 6×107 M⊙. As observed from Chandra X-ray Observatory, NGC 2681 displayed three stellar sources within the central kiloparsec of the galaxy. The active galactic nucleus had luminosity 1.8 × 1038 erg/s, which accounts for approximately the 20% of the total luminosity of the central kiloparsec.
References
External links
Lenticular galaxies
Seyfert galaxies
Ursa Major
2681
04645
24961 | NGC 2681 | [
"Astronomy"
] | 371 | [
"Ursa Major",
"Constellations"
] |
67,591,918 | https://en.wikipedia.org/wiki/Rugulosin | Rugulosin is an anthraquinoid mycotoxin with the molecular formula C30H22O10 which is produced by Penicillium species. Rugulosin is hepatotoxic and is cancerogenic.
References
Further reading
Mycotoxins | Rugulosin | [
"Chemistry"
] | 57 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
67,592,191 | https://en.wikipedia.org/wiki/Luteoskyrin | Luteoskyrin is a carcinogenic mycotoxin with the molecular formula C30H22O12 which is produced by the mold Penicillium islandicum. Luteoskyrin has strong cytotoxic effects. Luteoskyrin can cause the yellow rice disease.
References
Further reading
Mycotoxins
Polycyclic organic compounds | Luteoskyrin | [
"Chemistry"
] | 78 | [
"Organic compounds",
"Polycyclic organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
67,592,206 | https://en.wikipedia.org/wiki/Reverse%20waterfall | Reverse waterfall is a phenomenon in which water is blown upward due to strong wind in waterfalls giving an apparent perception of water flowing upwards. Strong blowing of wind above about 75 km/h can cause such phenomena.
List of observed location
These have been observed in Australia, India, Japan, the UK, the US and various parts of the world where there is chance of strong wind such as:
Australia: A wind of 70 km/h caused reverse waterfalls in various location in Sydney, Central Coast, Mid North Coast, Hunter, Illawarra areas and in the Royal National Park.
India:
A waterfall at Naneghat in Malshej Ghat Road near Mumbai
Samrad village in the Sandhan Valley has waterfalls showing reverse waterfall during monsoon.
Amboli hills near Belgaum have various waterfalls that becomes active in monsoon which gets blown upward due to strong wind.
Japan: Shiretoko National Park in Japan has Furepe Falls to the Sea of Okhotosk. This fall also gets reversed during strong wind.
Brazil: In the Chapada Diamantina National Park the Cachoeira da Fumaça (Smoke Waterfall) shows the phenomenon.
Chile: The waterfall in Talca shows the phenomenon.
United Kingdom: Has been observed in the Peak District amongst other highland areas, commonly in autumn and winter when strong winds can occur. The Kinder Downfall waterfall in the Kinder Scout area of the Peak District regularly exhibits this phenomenon.
"Ireland": at the Cliffs of Moher, during storm Ciaran (November, 2023).
United States:
Observed on a cliff in Ivins, Utah, Utah on 16 January 2023. Winds created updrafts strong enough to spray the waterfall upwards to the plateau.
The Waipuhia Falls in Oahu, Hawaii gets reversed due to north-easterly trade winds.
References
Earth phenomena
Waterfalls | Reverse waterfall | [
"Physics"
] | 376 | [
"Physical phenomena",
"Earth phenomena"
] |
67,592,296 | https://en.wikipedia.org/wiki/Cold%20data | In computer storage, cold data refers to data that is rarely accessed, therefore considered "cold".
Cold data is the opposite of hot data, which is data that is frequently accessed.
Uses
To optimize storage costs, cold data can be stored on lower performing and less expensive storage media. For example, solid state disks may be used for storing hot data, while cold data can be moved to hard drives, optical discs, tapes, or migrated to cloud storage.
See also
References
Data storage
Computer data storage
Backup | Cold data | [
"Engineering"
] | 105 | [
"Reliability engineering",
"Backup"
] |
67,594,543 | https://en.wikipedia.org/wiki/Hantzsch%20pyridine%20synthesis | The Hantzsch pyridine synthesis or Hantzsch dihydropyridine synthesis is a multi-component organic reaction between an aldehyde such as formaldehyde, 2 equivalents of a β-keto ester such as ethyl acetoacetate and a nitrogen donor such as ammonium acetate or ammonia. The initial reaction product is a dihydropyridine which can be oxidized in a subsequent step to a pyridine. The driving force for this second reaction step is aromatization. This reaction was reported in 1881 by Arthur Rudolf Hantzsch.
A 1,4-dihydropyridine dicarboxylate is also called a 1,4-DHP compound or a Hantzsch ester. These compounds are an important class of calcium channel blockers and as such commercialized in for instance nifedipine, amlodipine or nimodipine.
The reaction has been demonstrated to proceed in water as reaction solvent and with direct aromatization by ferric chloride, manganese dioxide or potassium permanganate in a one-pot synthesis.
The Hantzsch dihydropyridine synthesis has been effected by microwave chemistry.
Mechanism
At least five significant pathways have been proposed for the Hantzch reaction synthesis of 1,4-dihydropyridine. Low yield and unexpected products may arise under varying reactants and reaction conditions. Previous studies have tested the reactions of preformed intermediates to determine the most likely mechanism and design successful syntheses. An early study into the mechanism using 13C and 15N NMR indicated the intermediacy of the chalcone 6 and enamine 3. This data suggested the following route for the reaction.
Later research using mass spectrometry monitoring with charge-tagged reactants supported intermediate pathway A as a likely route and showed evidence that the reaction followed two additional intermediate pathways which converge to precursor 7. Reagents likely influence the route taken as when the methyl group of 1 is replaced by an electron-withdrawing group, the reaction instead proceeds through a diketone intermediate.
Optimization of reaction conditions
The classical method for synthesis of Hantzsch 1,4-dihydropyridines, which involves a one-pot condensation of aldehydes with ethyl acetoacetate and ammonia, have several drawbacks such as harsh reaction conditions, long reaction times, and generally low yield of products. A synthesis of 1,4-dihydropyridines in aqueous micelles catalyzed by PTSA under ultrasonic irradiation. Using condensation of benzaldehyde, ethyl acetoacetate and ammonium acetate as a model, experiments have proven that when catalyzed by p-toluenesulfonic acid (PTSA) under ultrasonic irradiation, the reaction can have a product yield of 96% in aqueous (SDS, 0.1M). The reaction had also been carried out in various solvent system, and it was discovered that the ultrasonic irradiation in aqueous micelles gave better yields than in solvents such as methanol, ethanol, THF. Using the optimized reaction conditions, a series of 1,4-dihydropyridine were synthesized, and they all have a reaction yield above 90%.
Aromatization
Oxidation of 1,4-DHPs accounts for one of the easiest ways of accessing pyridine derivatives. Common oxidants used to promote aromatization of 1,4-DHPs are CrO3, KMnO4, and HNO3. However, aromatization is often accompanied by: low chemical yields, strong oxidative conditions, burdensome workups, the formation of side products, or the need of excess oxidant. As such, particular attention has been paid to developing methods of aromatization to yield pyridine derivatives under milder and efficient conditions. Such conditions include, but are not limited to: iodine in refluxing methanol, chromium dioxide(CrO2), sodium chlorite, and under metal-free, photochemical conditions using both UV-light and visible light. Upon metabolism, 1,4-DHP based antihypertensive drugs undergo oxidation by way of cytochrome P-450 in the liver and are thus converted to their pyridine derivatives. As a result, particular attention has been paid to the aromatization of 1,4-DHPs as a means to understand biological systems and so as to develop new methods of accessing pyridines.
Green chemistry
As a multi-component reaction, the Hantzsch pyridine synthesis is much more atom efficient with a simpler number of reaction steps than a linear-strategy synthesis.In recent years, research has looked to make this an even more environmentally friendly reaction by investigating "greener" solvents and reaction conditions. One line of study has experimented with using ionic liquids as catalysts for room temperature reactions. Ionic liquids are an easy to handle and non-toxic option to replace traditional catalysts. Additionally, this catalyst lead to a high yield at room temperature, reducing the impact of heating the reaction for an extended time. A second study used ceric ammonium nitrate (CAN) as an alternate catalyst and achieved a solvent-free room temperature reaction.
Knoevenagel–Fries modification
The Knoevenagel–Fries modification allows for the synthesis of unsymmetrical pyridine compounds.
See also
Hantzsch pyrrole synthesis
1,4-Dihydropyridine
References
Pyridine forming reactions
Name reactions
Multiple component reactions | Hantzsch pyridine synthesis | [
"Chemistry"
] | 1,178 | [
"Name reactions",
"Ring forming reactions",
"Organic reactions"
] |
67,595,838 | https://en.wikipedia.org/wiki/Hamiltonian%20truncation | Hamiltonian truncation is a numerical method used to study quantum field theories (QFTs) in spacetime dimensions. Hamiltonian truncation is an adaptation of the Rayleigh–Ritz method from quantum mechanics. It is closely related to the exact diagonalization method used to treat spin systems in condensed matter physics. The method is typically used to study QFTs on spacetimes of the form , specifically to compute the spectrum of the Hamiltonian along . A key feature of Hamiltonian truncation is that an explicit ultraviolet cutoff is introduced, akin to the lattice spacing a in lattice Monte Carlo methods. Since Hamiltonian truncation is a nonperturbative method, it can be used to study strong-coupling phenomena like spontaneous symmetry breaking.
Principles
Energy cutoff
Local quantum field theories can be defined on any manifold. Often, the spacetime of interest includes a copy of , like (flat space), (an infinite hollow cylinder), (space is taken to be a torus) or even Anti-de Sitter space in global coordinates. On such a manifold we can take time to run along , such that energies are conserved. Solving such a QFT amounts to finding the spectrum and eigenstates of the Hamiltonian H, which is difficult or impossible to do analytically. Hamiltonian truncation provides a strategy to compute the spectrum of H to arbitrary precision. The idea is that many QFT Hamiltonians can be written as the sum of "free" part and an "interacting" part that describes interactions (for example a term or a Yukawa coupling), schematically
where V can be written as the integral of a local operator over M. There may be multiple interaction terms , but that case generalizes straightforwardly from the case with a single interaction . Hamiltonian truncation amounts to the following recipe:
Fix a UV cutoff , and find all eigenstates of with energy . Normalize these eigenstates such that . Let be the number of low-energy states.
Compute the Hamiltonian explicitly restricted to these low-energy states. The result will be a matrix of size , explicitly with
Compute the energies and eigenstates of the finite matrix , obeying .
In a UV-finite quantum field theory, the resulting energies have a finite limit as the cutoff is taken to infinity, so at least in principle the exact spectrum of the Hamiltonian can be recovered. In practice the cutoff is always finite, and the procedure is performed on a computer.
Range of validity
For a given cutoff , Hamiltonian truncation has a finite range of validity, meaning that cutoff errors become important when the coupling g is too large. To make this precise, let's take R to be the rough size of the manifold M, that is to say that
up to some c-number coefficient. If the deformation V is the integral of a local operator of dimension , then the coupling g will have mass dimension , so the redefined coupling
is dimensionless. Depending on the order of magnitude of , we can distinguish three different regimes:
: perturbation theory is valid. Generically, perturbation theory is either asymptotic or it converges up to some value . For infinitesimal values of , quantum effects can be neglected.
: perturbation theory is no longer reliable, but the truncated energies provide a good approximation to their continuum values for reasonable values of the cutoff .
: for very large values of (or equivalently, when the volume of M becomes very large), Hamiltonian truncation only provides good results when the cutoff is taken to be astronomically large. In practice, this regime is not accessible. This is an avatar of the orthogonality catastrophe.
Truncation errors and ultraviolet divergences
There are two intrinsic but related issues with Hamiltonian truncation:
In some cases, the do not have a finite limit as .
Even when the continuum limit exists, we only have access to cutoff data for a range of finite values of the cutoff.
The first case is due to ultraviolet divergences of the quantum field theory in question. In this case, cutoff-dependent counterterms must be added to the Hamiltonian H in order to obtain a physically meaningful result. In order to understand the second problem, one can perform perturbative computations to understand the continuum limit analytically.
Let us spell this out using an example. We have in mind a perturbation of the form gV with
where is a local operator. Suppose that we want to compute the first corrections to the vacuum energy due to V. In Rayleigh–Schrödinger perturbation theory, we know that
where
where the sum runs over all states other than the vacuum itself. Whether this integral converges or not depends on the large-E behavior of the spectral density . In turn, this depends on the short-distance behavior of the two-point correlation function of the operator . Indeed, we can write
where evolves in Euclidean time in the interaction picture.
Hence the large-E behavior of the spectral density encodes the short-time behavior of the vacuum correlator, where both x,y are integrated over space. The large-E scaling can be computed in explicit theories; in general it goes as
where is the scaling or mass dimension of the operator and c is some constant.
There are now two possibilities, depending on the value of :
If , the truncated Casimir energy diverges in the continuum limit. In this case, a cutoff-dependent counterterm must be added to H in order to cancel this divergence.
If , the truncated Casimir energy converges as . The truncation error can be estimated to be
A similar analysis applies to cutoff errors in excited states and at higher orders in perturbation theory.
Example of the massive scalar theory
Quantization
As an example, we can consider a massive scalar field on some spacetime , where M is compact (possibly having a boundary). The total metric can be written as
Let's consider the action
where is the Laplacian on . The g=0 theory can be canonically quantized, which endows the field with a mode decomposition
where the creation and annihilation operators obey canonical commutation relations . The single-particle energies and the mode functions depend on the spatial manifold M. The Hamiltonian at t=0 is then given by
Hamiltonian truncation
The Hilbert space of the theory is the Fock space of the modes . That is to say that there exists a vacuum state obeying for all n, and on top of that there are single- and multi-particle states. Explicitly, a general eigenstate of is labeled by a tuple of occupation numbers:
where the can take values in the integers: .
Such a state has energy
so finding a basis of low-energy states amounts to finding all tuples obeying . Let's denote all such states schematically as . Next, the matrix elements can be computed explicitly using the canonical commutation relations. Finally, the explicit Hamiltonian has to be diagonalized.
The resulting spectra can be used to study precision physics. Depending on the values of g and , the above theory can be in a symmetry-preserving or a symmetry-broken phase, which can be studied explicitly using the above algorithm. The continuous phase transition between these two phases can also be analyzed, in which case the spectrum and eigenstates of H contain information about the conformal field theory of the Ising universality class.
Special cases
Truncated Conformal Space Approach
The truncated conformal space approach (TCSA) is a version of the Hamiltonian truncation that applies to perturbed conformal field theories. This approach was introduced by Yurov and Al. Zamolodchikov in 1990
and has become a standard ingredient used to study two-dimensional QFTs. The d-dimensional version of TCSA was first studied in 2014.
A RG flow emanating from a conformal field theory (CFT) is described by an action
where is a scalar operator in the CFT of scaling dimension . At large distances, such theories are strongly coupled. It is convenient to study such RG flows on the cylinder , taking the sphere to have radius R and endowing the full space with coordinates . The reason is that the unperturbed (g=0) theory admits a simple description owing to radial quantization. Schematically, states on the cylinder are in one-to-one correspondence with local operators inserted at the origin of flat space:
where is the CFT vacuum state. The Hamiltonian on the cylinder is precisely the dilatation operator D of the CFT: the unperturbed energies are given by
where is the scaling dimension of the operator . Finally, the matrix elements of the deformation V
are proportional to OPE coefficients in the original CFT.
Lightcone truncation methods
Real-time QFTs are often studied in lightcone coordinates
Although the spectrum of the lightcone Hamiltonian is continuous, it is still possible to compute certain observables using truncation methods. The most commonly used scheme, used when the UV theory is conformal, is known as lightcone conformal truncation (LCT). Notably, the spatial manifold M is non-compact in this case, unlike the equal-time quantization described previously. See also the page for light-front computational methods, which describes related computational setups.
Numerical implementation
Hamiltonian truncation computations are normally performed using a computer algebra system, or a programming language like Python or C++.
The number of low-energy states tends to grow rapidly with the UV cutoff, and it is common to perform Hamiltonian truncation computations taking into account several thousand states. Nonetheless, one is often only interested in the first O(10) energies and eigenstates of H. Instead of diagonalizing the full Hamiltonian explicitly (which is numerically very costly), approximation methods like Arnoldi iteration and the Lanczos algorithm are commonly used.
In some cases, it is not possible to orthonormalize the low-energy states , either because this is numerically expensive or because the underlying Hilbert space is not positive definite. In that case, one has to solve the generalized eigenvalue problem
where and is the Gram matrix of the theory. In this formulation, the eigenstates of the truncated Hamiltonian are .
In practice, it is important to keep track of the symmetries of the theory, that is to say all generators that satisfy . There are two types of symmetries in Hamiltonian truncation:
Global symmetries, for instance the symmetry in theory.
Symmetries of the spatial manifold M, for instance the orthogonal group when .
When all states are organized in symmetry sectors with respect to the the Hamiltonian is block diagonal, so the effort required to diagonalize H is reduced.
References
Quantum field theory
Quantum mechanics | Hamiltonian truncation | [
"Physics"
] | 2,257 | [
"Quantum field theory",
"Theoretical physics",
"Quantum mechanics"
] |
67,596,148 | https://en.wikipedia.org/wiki/Coralloidiomyces | Coralloidiomyces is a genus of fungi belonging to the order Rhizophydiales, family unknown.
The species of this genus are found in Denmark.
Species:
Coralloidiomyces digitatus Letcher
References
Chytridiomycota
Chytridiomycota genera | Coralloidiomyces | [
"Biology"
] | 63 | [
"Fungus stubs",
"Fungi"
] |
67,596,445 | https://en.wikipedia.org/wiki/Fennellomyces | Fennellomyces is a genus of fungi belonging to the family Syncephalastraceae.
Species:
Fennellomyces gigacellularis
Fennellomyces heterothallicus
Fennellomyces linderi
Fennellomyces verticillatus
References
Fungi | Fennellomyces | [
"Biology"
] | 59 | [
"Fungi"
] |
67,596,513 | https://en.wikipedia.org/wiki/Globomyces | Globomyces is a genus of fungi belonging to the family Globomycetaceae.
The species of this genus are found in Europe.
Species:
Globomyces pollinis-pini (A.Braun) Letcher
References
Chytridiomycota
Chytridiomycota genera | Globomyces | [
"Biology"
] | 70 | [
"Fungus stubs",
"Fungi"
] |
67,596,528 | https://en.wikipedia.org/wiki/Gorgonomyces | Gorgonomyces is a genus of fungi belonging to the family Gorgonomycetaceae.
Species:
Gorgonomyces haynaldii (Schaarschm.) Letcher
References
Chytridiomycota
Chytridiomycota genera | Gorgonomyces | [
"Biology"
] | 61 | [
"Fungus stubs",
"Fungi"
] |
67,596,548 | https://en.wikipedia.org/wiki/Halteromyces | Halteromyces is a genus of fungi belonging to the family Cunninghamellaceae.
Species:
Halteromyces radiatus Shipton & Schipper
References
Fungi | Halteromyces | [
"Biology"
] | 36 | [
"Fungi"
] |
67,596,590 | https://en.wikipedia.org/wiki/Kappamyces | Kappamyces is a genus of fungi belonging to the family Kappamycetaceae.
The species of this genus are found in Southeastern Asia and Australia.
Species:
Kappamyces laurelensis Letcher & M.J.Powell
References
Chytridiomycota
Chytridiomycota genera | Kappamyces | [
"Biology"
] | 64 | [
"Fungus stubs",
"Fungi"
] |
67,596,607 | https://en.wikipedia.org/wiki/Kochiomyces | Kochiomyces is a genus of fungi belonging to the family Spizellomycetaceae.
The species of this genus are found in Denmark.
Species:
Kochiomyces dichotomus (Umphlett) D.J.S.Barr
References
Chytridiomycota
Chytridiomycota genera | Kochiomyces | [
"Biology"
] | 69 | [
"Fungus stubs",
"Fungi"
] |
67,596,942 | https://en.wikipedia.org/wiki/Camille%20No%C3%BBs | Camille Noûs is a fictional name assumed by the French collective academic project RogueESR. The character of "Camille Noûs" was created in 2020 when the group signed an open letter concerning French science policy. "Camille Noûs" has been listed as an author on 180 journal papers in several scientific disciplines.
Background
The intent of the Camille Noûs character has been described as a protest against changes in research culture, including the rise of temporary academic positions, the decline in researcher job security and tenure protections, and research assessment metrics that emphasise citation numbers.
The Camille Noûs campaign has been criticized as "ethically questionable" due to concerns about responsibility and accountability for research results. There has also been criticism that has arisen from some researchers including Camille Noûs on the author list without informing journal editors that it is a fictitious name.
The intention of the Camille Noûs character is to protest individualism in scientific research, and to promote collaboration over individual accomplishment.
In April 2021, a manifesto by Camille Noûs was published on the science blog 3 Quarks Daily.
See also
Citation impact
Scientific citation
References
Sources
Further reading
RogueESR, . & Noûs, C. (2023). Comment Camille devint Noûs. La Pensée, 414, 108-111. https://doi.org/10.3917/lp.414.0108
Camille Noûs and Collective of Journals in Struggle. (2019). Why French Academic Journals are Protesting. European Journal of Turkish Studies, 29. https://doi.org/10.4000/ejts.6441
External links
Who is Camille Noûs, the fictitious French researcher with nearly 200 papers?
We, Camille Noûs -Research As A Common
2020 in science
Academic journal articles
Academic scandals
Science and technology studies
Scientific misconduct incidents
Sociology of scientific knowledge | Camille Noûs | [
"Technology"
] | 375 | [
"Science and technology studies"
] |
67,597,535 | https://en.wikipedia.org/wiki/Monoblepharis | Monoblepharis is a genus of fungi belonging to the family Monoblepharidaceae.
The genus has almost cosmopolitan distribution.
Species
Species:
Monoblepharis bullata
Monoblepharis fasciculata
Monoblepharis hypogyna
Monoblepharis insignis
Monoblepharis laevis
Monoblepharis macranda
Monoblepharis macrandra
Monoblepharis micrandra
Monoblepharis ovigera
Monoblepharis polymorpha
Monoblepharis regignens
Monoblepharis sphaerica
Monoblepharis thalassinosa
References
Fungi | Monoblepharis | [
"Biology"
] | 128 | [
"Fungi"
] |
67,599,601 | https://en.wikipedia.org/wiki/HD%20141399 | HD 141399 is a K-type main-sequence star 121 light-years away in the constellation of Boötes. Its surface temperature is 5602 K. HD 141399 is enriched in heavy elements compared to the Sun, with a metallicity Fe/H index of 0.36. Its age is unknown. The star has very low starspot activity.
Planetary system
In 2014, four planets orbiting HD 141399 were discovered by the radial velocity method. Planet HD 141399c is possibly located within the habitable zone. The planetary orbits are close to high-order mean-motion resonance and closely conform to the Titius–Bode law. Two additional planets, one with a period of 462.9 days, are suspected by analogy with the orbits of the Solar System planets. The planetary orbits around HD 141399 are expected to "jump" periodically on a timescale of a few million years between several quasi-stable configurations due to planet-planet interactions. HD 141399 is one of only two known planetary systems consisting of at least four massive gas giants (the other is the system of planets around the young star HR 8799).
References
Boötes
K-type main-sequence stars
Planetary systems with four confirmed planets
J15465382+4659105
077301
BD+47 2267
141399 | HD 141399 | [
"Astronomy"
] | 280 | [
"Boötes",
"Constellations"
] |
67,601,526 | https://en.wikipedia.org/wiki/Jean-Luc%20Sandoz | Jean-Luc Sandoz (born 1960 in Montandon) is a French-Swiss engineer and an expert in wood construction. He is the founder of several companies in the field of engineering, industrialization, construction and expertise, all related to wood. Formerly, he was a professor and lecturer at EPFL (École Polytechnique Fédérale de Lausanne).
Career
Born into a family of farmers in the Haut-Doubs region, he became acquainted with the material wood, starting with a vocational training certificate in carpentry, followed by a BEP (vocational training certificate) in cabinetmaking, before joining the Lycée Bois de Mouchard in 1976, where he obtained a BTS (vocational training certificate) in wood construction.
After studies at ENSTIB (École Nationale Supérieure des Technologies et des Industries du Bois), in 1985, he began his thesis on the subject of ultrasound and the mechanical strength of wood, under the direction of Julius Natterer at EPFL. He obtained his PhD in 1990 for his thesis entitled "Triage et fiabilité des bois de construction: validité de la méthode ultrason" (Sorting and reliability of construction timber: validity of the ultrasonic method).
He continued research at the IBOIS (Laboratory for Timber Construction) at EPFL in two areas: non-destructive technologies to measure the mechanical quality of wood material and the optimisation of wooden structures for the application in large buildings.
In 1993, he was appointed assistant professor at EPFL.
Together with Julius Natterer and Martial Rey, Sandoz authored the textbook "Construction en Bois" (Wood Construction that has remained in print since its release in 1996 (20 new editions).
During this period he organised several international symposia among them the Symposium on Nondestructive Testing of Wood and the World Conference on Timber Engineering.
He registered several patents such as for a device for measuring the characteristics of wood using ultrasound (Sylvatest), and an application for measuring wooden poles for overhead electricity and telephone lines (K-Store & Polux), as well as for the construction of wood and mixed wood-concrete slabs as the Ariane truss.
In 1999, Sandoz left the academic world to devote himself to his company CBS-Lifteam.
Wooden structures
Sandoz integrates wood in all types of structures and buildings and optimises spans and heights, as well as for thermal and acoustic performance. Several of his projects won awards.
Examples of Sandoz' structures:
In 2000, he inspected the wooden structure of the Valère Basilica in Sion.
For the Swiss national exhibition Expo.02 in 2002, he designed and built the offshore platforms that were placed on the lakes of Neuchâtel and Bienne to house the temporary exhibition pavilions. Made of local wood, the entire wooden structure was dismantled and reused after the expo period.
In 2006–2007, he inspected the residual performance of the wooden structure of the Forbidden City in Beijing
In 2017, he collaborated on the construction of the Guiana Space Centre and helped with the characterisation and employment of local wood from the Amazonian forest.
In 2019, he used wood to clad the Vortex building, which served as the Olympic village for the 2020 Winter Youth Olympic Games in Lausanne before taking on its present function as student accommodation
Selected works
References
External links
Website of the company CBS-CBT
1960 births
Living people
École Polytechnique Fédérale de Lausanne alumni
Structural engineers
French engineers
Swiss engineers | Jean-Luc Sandoz | [
"Engineering"
] | 708 | [
"Structural engineering",
"Structural engineers"
] |
67,601,864 | https://en.wikipedia.org/wiki/List%20of%20presentation%20programs | The following is a list of notable presentation software.
Free and open-source software
Apache OpenOffice Impress - Linux, macOS, Windows
Beamer - Unix-like, Windows
Calligra Stage - Linux, Windows
Collabora Online - Android, ChromeOS, iOS, iPadOS, Linux, macOS, Windows
LibreOffice Impress - Android, Linux, macOS, Windows, unofficial: ChromeOS, FreeBSD, Haiku, iOS, iPadOS, NetBSD, OpenBSD, Solaris
OnlyOffice Desktop Editors - Android, iOS, macOS, Linux, Windows
Powerdot - LaTeX
Proprietary software
Commercial
Apple Keynote - MacOS
Corel Presentations - Windows
Hancom Office - Android, iOS, macOS, Windows
Microsoft PowerPoint - Mac, Windows
Polaris Office - Android, iOS, MacOS, Windows
QuickOffice - Android, BlackBerry, iOS, Palm, Symbian, webOS
SoftMaker Presentations - Android, iOS, Linux, macOS, Windows
WPS Office Presentation - Android, iOS, Fire OS, Linux, Windows
Freeware
Atlantis Nova - Windows
Baraha - Windows
Bean - Mac OS X
SoftMaker Presentations - Android, iOS, Linux, macOS, Windows
WPS Office Presentation Personal Edition - Android, Fire OS, HarmonyOS, iOS, Linux, Windows
Online
Apple Keynote
Brainshark
Google Slides
Hancom Office Show
Mentimeter
Microsoft PowerPoint Online – free online service
Microsoft Sway
OnlyOffice
Prezi
SlideShare
Wooclap
Canva
Historical
Adobe Persuasion - Classic Mac OS, Windows
AppleWorks (formerly ClarisWorks presentation editing) - Classic Mac OS, Mac OS X, Windows 2000 or later
CA-Cricket Presents - Apple Macintosh, Windows
Gobe Productive - BeOS, Linux, Windows
Harvard Graphics - DOS, Windows
IBM Lotus Symphony - Linux, Mac OS X, Windows
Lotus Freelance Graphics - Windows
Jarte - Windows
MagicPoint - Unix-like
NeoOffice - macOS
Microsoft PowerPoint Viewer - Windows
SlideRocket - Web-based
See also
List of office suites
Presentation program
References
Presentation software
presentation programs | List of presentation programs | [
"Technology"
] | 422 | [
"Computing-related lists",
"Lists of software"
] |
67,601,948 | https://en.wikipedia.org/wiki/Bioinstructive%20material | Bioinstructive materials provide instruction to biological cells or tissue, for example immune instruction when monocytes are cultured on certain polymers they polarise to pro- or anti-inflammatory macrophages with potential applications in implanted devices, or materials for the repair of musculoskeletal tissues. Due to the paucity of information on the mechanism of materials control of cells, beyond the general recognition of the important role of adsorbed biomolecules, high throughput screening of large libraries of materials, topographies, and shapes are often used to identify cell instructive material systems. Applications of bioinstructive materials as substrates for stem cell production, cell delivery and reduction of foreign body reaction and coatings to reduce infections on medical devices. This non-leaching approach is distinct from strategies of infection control relying on antibiotic release, cytokine delivery or guidance of cells by surface located epitopes inspired by nature.
Multifunctional alginate scaffolds for T cell engineering and release
An example of bioinstructive scaffolds utilized is the Multifunctional alginate scaffolds for T cell engineering and release (MASTER). MASTER is technique for in situ engineering, replication and release of genetically engineered T cells. It is an evolution of CAR-T cell therapy. T cells are extracted from the patient and mixed with a genetically engineered virus that contains a cancer targeting gene (as with CAR T). The mixture is then added to a MASTER (scaffold), which absorbs them. The MASTER contains antibodies that activate the T cells and interleukins that trigger cell proliferation. The MASTER is then implanted into the patient. The activated T cells interact with the viruses to become CAR T cells. The interleukins stimulate these CAR T cells to proliferate, and the CAR T cells exit the MASTER to attack the cancer. The technique takes hours instead of weeks. And because the cells are younger, they last longer in the body, show stronger potency against cancer, and display fewer markers of exhaustion. These features were demonstrated in mouse models. The treatment was more effective and longer lasting against lymphoma.
References
Biotechnology | Bioinstructive material | [
"Biology"
] | 452 | [
"Biotechnology",
"nan"
] |
67,603,592 | https://en.wikipedia.org/wiki/5-Methyl-2-%28%282-nitrophenyl%29amino%29-3-thiophenecarbonitrile | 5-Methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, also known as ROY (red-orange-yellow), is an organic compound which is a chemical intermediate to the drug olanzapine. It has been the subject of intensive study because it can exist in multiple well-characterised crystalline polymorphic forms.
Synthesis
The preparation of ROY was first disclosed in a series of patents from Eli Lilly & Co. in the 1990s, which covered the pharmaceutical active ingredient later marketed as olanzapine. In the first step, a Gewald reaction using propionaldehyde, sulfur and malononitrile formed the thiophene ring system, as 2-amino-5-methylthiophene-3-carbonitrile. The amino group was then reacted with 2-fluoro-nitrobenzene in tetrahydrofuran to provide 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile.
Polymorphism
ROY has been crystallised in at least thirteen polymorphic forms. Five of them, including red, orange and yellow examples are shown in Figure 1.
When this ability to form multiple crystalline versions of different colours was reviewed in 2010, it was described as "extraordinary", particularly because many alternatives can crystallise simultaneously from a single solvent. As the thermodynamic properties of the various versions have been established, ROY has become an important test of computational models. By 2020, ROY held the record for having the largest number of well-characterised polymorphs, with its nearest competitors being aripiprazole and galunisertib. The various crystal forms display alternative conformers, a type of stereoisomerism where rotation at single bonds leads to a distinct three-dimensional configuration in the solid. The molecule is piezochromic, with yellow and pale orange crystalline forms which transform reversibly to red at high pressure.
In 2022, it was suggested that all the ROY polymorphs which are stable at ambient pressure have already been found and characterised. This work also calculated that additional polymorphs might be discovered using high pressures of about 10 GPa.
References
Thiophenes
Nitriles
Secondary amines
2-Nitrophenyl compounds | 5-Methyl-2-((2-nitrophenyl)amino)-3-thiophenecarbonitrile | [
"Chemistry"
] | 489 | [
"Nitriles",
"Functional groups"
] |
67,603,895 | https://en.wikipedia.org/wiki/Time%20in%20Lithuania | Time in Lithuania is given by Eastern European Time (EET; UTC+02:00). Daylight saving time, which moves one hour ahead to UTC+03:00 is observed from the last Sunday in March to the last Sunday in October. Latvia adopted EET in 1920.
History
Lithuania observed DST between 1941 and 1944, and since 1989 (with a brief break between 2000 and 2002).
IANA time zone database
In the IANA time zone database, Lithuania is given one zone in the file zone.tab – Europe/Vilnius. Data for Lithuania directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
See also
Time in Europe
List of time zones by country
List of time zones by UTC offset
References
External links
Current time in Lithuania at Time.is
Geography of Lithuania | Time in Lithuania | [
"Physics"
] | 173 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
67,604,799 | https://en.wikipedia.org/wiki/Time%20in%20Luxembourg | In Luxembourg, the standard time is Central European Time (CET; UTC+01:00). Daylight saving time is observed from the last Sunday in March (02:00 CET) to the last Sunday in October (03:00 CEST).
History
Luxembourg first introduced CET in 1904, but switched to UTC+00:00 in 1918. CET was reintroduced in 1940 under German occupation.
IANA time zone database
In the IANA time zone database, Luxembourg is given one zone in the file zone.tab – Europe/Luxembourg. Data for Luxembourg directly from zone.tab of the IANA time zone database; columns marked with * are the columns from zone.tab itself:
See also
Time in Europe
List of time zones by country
List of time zones by UTC offset
References
External links
Current time in Luxembourg at Time.is
Geography of Luxembourg | Time in Luxembourg | [
"Physics"
] | 175 | [
"Spacetime",
"Physical quantities",
"Time",
"Time by country"
] |
52,008,300 | https://en.wikipedia.org/wiki/Tomorrow%20%28time%29 | Tomorrow is a temporal construct of the relative future; literally of the day after the current day (today), or figuratively of future periods or times. Tomorrow is usually considered just beyond the present and counter to yesterday. It is important in time perception because it is the first direction the arrow of time takes humans on Earth.
Philosophy
The use of terms such as tomorrow, now and future are part an a-series view which is part of the presentism philosophy of time.
Learning and language
For a young child, "tomorrow" is "an undefined, infinite time of the idea that time is just an infinite and arbitrary definition of an yet unidentified of what we like to call time, yet the child slowly learns the meaning of tomorrow." The concept of "tomorrow" is rarely understood by 3-year-old children, but 4-year-olds understand the idea.
References
Future
Days | Tomorrow (time) | [
"Physics"
] | 181 | [
"Physical quantities",
"Time",
"Time stubs",
"Future",
"Spacetime"
] |
52,008,610 | https://en.wikipedia.org/wiki/ZYYX | ZYYX is a Swedish desktop 3D printer, designed primarily for office and educational applications. Originally launched in 2014 by Magicfirm Europe AB, based at Chalmers Innovation in Gothenburg, the ZYYX 3D Printer is based on FFF technology and features include an automated levelling function, smell-free operation (most 3D printers tend to smell heavily of hot plastic) and an extruder head which is less prone to jamming.
Models
The first model was released in 2014. The ZYYX 3D Printer was designed to provide an enclosed print environment with a fan and carbon filter to scrub fumes produced by the melted filament before exhausting them into the environment. The XYYZ+ Printer was released in 2016 to introduce improvements that provided a more stable printing environment.
See also
Comparison of 3D printers
Digital modeling and fabrication
List of 3D printer manufacturers
References
External links
Official website
3D printers
Computer-related introductions in 2014
2014 establishments in Sweden
Swedish brands
Robotics in Sweden
Fused filament fabrication
Chalmers University of Technology | ZYYX | [
"Technology",
"Engineering"
] | 204 | [
"Computer hardware stubs",
"Design stubs",
"3D printers",
"Computing stubs",
"Design",
"Industrial machinery"
] |
52,009,652 | https://en.wikipedia.org/wiki/List%20of%20U.S.%20states%20by%20changes%20in%20life%20expectancy%2C%201985%E2%80%932010 | This article ranks states of the United States sorted by changes in the life expectancy of their residents between 1985 and 2010. Changes in the life expectancy of men and women in each state are also sorted. States are also ranked for three risk factors controllable by the individual: obesity, smoking, and physical activity.
The data is taken from the Institute for Health Metrics and Evaluation, an independent global health research center at the University of Washington.
Note: May not add to total due to rounding.
Life expectancy (years)
Note: may not add to total due to rounding
Controllable risk factors
This list ranks U.S. states for three factors, controllable by the individual: obesity, smoking, and physical activity. These factors affect longevity: obesity and smoking reduce longevity and a higher level of physical activity increases longevity.
See also
List of U.S. states and territories by life expectancy
List of U.S. counties with shortest life expectancy
List of U.S. counties with longest life expectancy
References
Life expectancy changes,1985
State life expectancy changes,1985
Life expectancy changes,1985
Lists of people-related superlatives
United States | List of U.S. states by changes in life expectancy, 1985–2010 | [
"Biology"
] | 240 | [
"Senescence",
"Life expectancy"
] |
52,010,423 | https://en.wikipedia.org/wiki/Maximum%20agreement%20subtree%20problem | The maximum agreement subtree problem is any of several closely related problems in graph theory and computer science. In all of these problems one is given a collection of trees each containing leaves. The leaves of these trees are given labels from some set with so that no pair of leaves in the same tree sharing the same label, within the same tree the labelling for each leaf is distinct. In this problem one would like to find the largest subset such that the minimal spanning subtrees containing the leaves in , of are the "same" while preserving the labelling.
Formulations
Maximum homeomorphic agreement subtree
Source:
This version requires that the subtrees are homeomorphic to one another.
Rooted maximum homeomorphic agreement subtree
This version is the same as the maximum homeomorphic agreement subtree, but we further assume that are rooted and that the subtrees contain the root node. This version of the maximum agreement subtree problem is used for the study of phylogenetic trees. Because of its close ties with phylogeny this formulation is often what is mean when one refers to the "maximum agreement subtree" problem.
Other variants
There exits other formulations for example the (rooted) maximum isomorphic agreement subtree where we require the subtrees to be isomorphic to one another.
See also
Frequent subtree mining
References
Computational problems in graph theory | Maximum agreement subtree problem | [
"Mathematics"
] | 272 | [
"Computational problems in graph theory",
"Computational mathematics",
"Graph theory",
"Computational problems",
"Mathematical relations",
"Mathematical problems"
] |
52,010,888 | https://en.wikipedia.org/wiki/Initiator%20protein | The initiator proteins are the proteins that recognize a specific DNA sequence within the origin of replication. The origin of replication is the site where the helicase attaches to the template strand and starts to unwind the DNA into two strands.
References
Proteins by function | Initiator protein | [
"Chemistry"
] | 55 | [
"Biochemistry stubs",
"Protein stubs"
] |
52,011,522 | https://en.wikipedia.org/wiki/Dido%20%28train%29 | In British railway parlance Dido trains were typically provided to transport workers to a remote place of railway employment on a Day in, day out basis.
The most common provision of this nature was to engine sheds away from centres of population where substantial numbers of staff would need to travel to or from work at times when other forms of public transport were not available. An example of this was the "Annesley Dido" which served the Great Central Railway-built Annesley engine shed north of Nottingham from at least 1929 to 8 September 1962.
A variant on this theme occurred to and from Langwith Junction engine shed in Derbyshire. This service was provided after Tuxford engine shed closed in 1959, when many Tuxford staff were transferred to work at Langwith Junction.
Workmen's trains
Dido trains were a variant within the broad class of workmen's trains which were provided by railways from their early days until well after the Second World War. Such trains ran to meet the needs of people working at establishments with significant numbers signing on and off at given times, such as collieries, factories, quarries, docks and railway workshops. Such trains were often made up of substandard coaching stock hauled by ancient locomotives, with occasional exceptions when a service's customary locomotive was indisposed. By the nature of their destinations such trains often required special platforms or other stopping places, which usually did not appear on public timetables and did not cater for the general public. Like the rolling stock, these stations were typically substandard, amounting in some cases to an agreed stopping point where users clambered to and from the trackside.
Where public stations existed near places of employment some workmen's trains called, usually not shown on the station's public timetable. Occasionally workmen's carriages were attached to regular service trains.
Whatever the variety of workmen's service used, passengers bought "workmen's tickets" at significantly reduced fares.
Examples
Many workmen's services existed over the years. Examples were provided by:
the Festiniog and Blaenau Railway to for the quarries at Blaenau Ffestiniog
the Great Western Railway to for the quarries at Blaenau Ffestiniog
the Lowca Light Railway to for the colliery, washery and coking plant at Lowca
the London and North Western Railway to for the same places
the London and North Western Railway along the Willis Branch to Huyton Quarry
the London, Midland and Scottish Railway to ROF Chorley
contractors to whilst Immingham Docks were under construction
the Padarn Railway to the Dinorwic Slate Quarries
the Penrhyn Quarry Railway to the Penrhyn Quarry
the Great Central Railway to and from to
Trafford Park Estates Co.from Barton to the Third Avenue tram route
British Railways to for Barrow docks
the Cleator and Workington Junction Railway to and for Walkmill Colliery
References
Sources
Trains
Passenger rail transport in the United Kingdom | Dido (train) | [
"Technology"
] | 598 | [
"Trains",
"Transport systems"
] |
52,011,926 | https://en.wikipedia.org/wiki/Teissier%20affair | The Teissier affair was a controversy that occurred in France in 2001. French astrologer Élizabeth Teissier was awarded a doctorate in sociology by Paris Descartes University for a doctoral thesis in which she argued that astrology was being oppressed by science. Her work was contested by the scientific community within the context of the science wars, and compared to the Sokal hoax. Criticisms included the alleged failure to work within the field of sociology and also lacking the necessary scientific rigour for a doctoral thesis in any scientific field. The university and jury who awarded the degree were harshly criticised, though both they and Teissier had supporters and defenders.
Teissier's doctorate
On April 7, 2001, Elizabeth Teissier defended her thesis entitled Situation épistémologique de l'astrologie à travers l'ambivalence fascination-rejet dans les sociétés postmodernes ("The Epistemological Situation of Astrology in Relation to the Ambivalent Fascination/Rejection of Postmodern Societies") – accounts of the defense have been published. Her studies at the University of Paris Descartes were under the supervision of Michel Maffesoli, an Emeritus Professor of Sociology. The central idea of the thesis was described by The New York Times as being that astrology is being oppressed by science, which Teissier called "official science" and "monolithic thought". Teissier argued, however, that her work is devoid of bias and had "focused only on the misunderstanding that astrology as a multimillennial knowledge vehicle" provokes. Her prepared statement was enthusiastically received by her supporters, but there was also a declaration from the editor-in-chief of Science et Vie Junior that what was occurring was a "farce". At end of the defense, the jury deliberated only briefly before Serge Moscovici admitted Teissier to her doctoral degree with the "very honourable" distinction.
Initial reaction
Controversy erupted in the scientific community following the decision, and several sociologists also publicly challenged its legitimacy. The university was criticised for granting the degree, as was the jury, along with Teissier's statements in support of astrology as a science, though the university rejected accusations of "irresponsibility". A petition signed by over 370 sociologists was sent to Professor Pierre Daumard, the President of the university; he responded that the Teissier had complied with all university requirements and it is not his place to question the "guarantees of the scientific validity of the thesis" from the independent jury. Daumard also defended that astrology is a legitimate subject for sociological study for its impact on society, a point on which Teissier's critics agreed. These critics were themselves criticised for their "incendiary" complaints which targeted her personally for her astrological beliefs instead of based on her thesis. Critics were also described as engaging in a witch-hunt whose true target was the academic reputation of Michel Maffesoli. Maffesoli addressed the controversy in an email on 23 April 2001, acknowledging that the thesis included some "slippages" but minimising the importance of these errors. Maffesoli added that there is a "manhunt" against him and more broadly against scientific and intellectual rigor in "diverse approaches to sociology", but still engaged with critics such as Christian Baudelot at an ASES-organised symposium on the Teissier affair. Maffesoli did state during the defense that he had tried to keep Teissier focused on the sociological impact of astrology rather than discussing its scientific legitimacy, while still maintaining that the thesis demonstrated sufficient sociological significance to justify awarding the doctorate.
AFIS analysis
Once the thesis was available following the defense, the Association française pour l'information scientifique (AFIS) organised a group to critique the thesis; the analysis was published by a multi-disciplinary group (two experts in pseudoscience, including the editor of the AFIS Science et pseudo-sciences, three astrophysicists, two sociologists, and a philosopher) on 6 August 2001. They looked at the scientific, philosophical, and sociological aspects of Teissier's thesis, describing it as "not a thesis in sociology but actually pro-astrological advocacy". They concluded that the Teissier's work did not meet the requirements of scientific rigor of doctoral research, regardless of the discipline in question. They described the jury as having accepted the thesis "in defiance of basic academic requirements of objectivity and intellectual honesty" in part because the AFIS group's multidisciplinary analysis shows that "no relevant standard (analytical rigor, objectivity, indication of sources, style of writing, etc.) had truly been fulfilled". They comment all Teissier has achieved is to "demonstrate once again that [astrology] does not deserve the status of an intellectual discipline that can be taught in a university course". According to the journal Skepter, the "thesis pretends to provide irrefutable proof that astrology is a science, but the author has no idea what constitutes a scientific proof, she is muddleminded about basic astronomical and astrological facts, and the pièce de resistance of her argument consists of statements about Michel Gauquelin which can only be called lies." Examples of excerpts from the thesis which bear this out, according to Broch, include unsupported medical claims, fundamental errors in astronomy, and a lack of proper evidence. Teissier was "completely appalled" that a "tiny group" would question the award of her doctorate and did not exclude the possibility of suing the AFIS, who published the critique of her thesis, after its "intolerable attack" on academic freedom.
Wider context
Discussion of the circumstances of Teissier's doctorate occurred and continues to occur with the context of the science wars, a dispute which pitted humanities academics taking postmodernist perspectives against scientists taking positivist and rationalist approaches. In particular, comparisons have been made to the Sokal hoax, in that each case exemplifies the alleged support for pseudoscience and hostility to science within postmodernist circles. The emphatic language and personalised tone of the debate around Teissier's work was fuelled by the broader ongoing conflict, as was the targeting of Maffesoli and the description of the university as "heavily influenced by so-called post-modern ideologists" (emphasis in original). It also explains criticisms of the jury for its failure to seek input from scientists (a bone of contention in the science wars), and the unusually personalised tone of comments such as that Teissier, "very astutely, has taken advantage of the intellectual weakness and/or incompetence of ... the nincompoops who accepted to ratify such nonsense" (bold emphases from original omitted).
References
2001 controversies
Controversies in France
Paris Descartes University
Education controversies in France
Theses
Astrology
2001 in France
History of sociology
Scientific controversies | Teissier affair | [
"Astronomy"
] | 1,448 | [
"Astrology",
"History of astronomy"
] |
52,012,420 | https://en.wikipedia.org/wiki/K%20band%20%28NATO%29 | The NATO K band is the obsolete designation given to the radio frequencies from 20 to 40 GHz (equivalent to wavelengths between 1.5 and 0.75 cm) during the cold war period. Since 1992 frequency allocations, allotment and assignments are in line to NATO Joint Civil/Military Frequency Agreement (NJFA).
However, in order to identify military radio spectrum requirements, e.g. for crises management planning, training, electronic warfare activities, or in military operations, this system is still in use.
References
Microwave bands
Satellite broadcasting | K band (NATO) | [
"Engineering"
] | 110 | [
"Telecommunications engineering",
"Satellite broadcasting"
] |
52,012,421 | https://en.wikipedia.org/wiki/K%20band%20%28infrared%29 | In infrared astronomy, the K band is an atmospheric transmission window centered on 2.2 μm (in the near-infrared 136 THz range). HgCdTe-based detectors are typically preferred for observing in this band.
Photometric systems used in astronomy are sets of filters or detectors that have well-defined windows of absorption, based around a central peak detection frequency and where the edges of the detection window are typically reported where sensitivity drops below 50% of peak. Various organizations have defined systems with various peak frequencies and cutoffs in the K band, including , and KS, and Kdark.
See also
Absolute magnitude
References
Electromagnetic spectrum
Infrared imaging | K band (infrared) | [
"Physics",
"Astronomy"
] | 133 | [
"Astronomy stubs",
"Spectrum (physical sciences)",
"Electromagnetic spectrum"
] |
52,012,422 | https://en.wikipedia.org/wiki/K%20band%20%28IEEE%29 | The IEEE K-band is a portion of the radio spectrum in the microwave range of frequencies from 18 to 27 gigahertz (GHz). The range of frequencies in the center of the K-band between 18 and 26.5 GHz are absorbed by water vapor in the atmosphere due to its resonance peak at 22.24 GHz, . Therefore these frequencies experience high atmospheric attenuation and cannot be used for long-distance applications. For this reason, the original K-band has been split into three bands: Ka-band, K-band, and Ku-band as detailed below.
The K stands for , the German word for 'short'.
Subdivisions
Because of the water vapor absorption peak in the center of the band, the IEEE K-band is conventionally divided into three sub-bands:
Ku-band (K-under band, 12–18 GHz): mainly used for satellite communications, direct-broadcast satellite television, terrestrial microwave communications, and radar, especially police traffic speed detectors.
K-band (18–27 GHz): due to the 22 GHz water vapor absorption line, this band has high atmospheric attenuation and is only useful for short-range applications.
Ka-band (K-above band, 26.5–40 GHz): mainly used for satellite communications, radar and experimental communications. NASA's Kepler space telescope is the first NASA mission to use Ka-band NASA Deep Space Network (NASA DSN) communications.
Amateur radio
The Radio Regulations of the International Telecommunication Union (ITU) allow amateur radio and amateur satellite operations in the frequency range 24.000 GHz to 24.250 GHz, which is known as the 1.2-centimeter band. It is also referred to as the K-band by AMSAT.
See also
K band (infrared)
K band (NATO)
K band (Radar Codes)
References
Microwave bands
Satellite broadcasting | K band (IEEE) | [
"Engineering"
] | 383 | [
"Telecommunications engineering",
"Satellite broadcasting"
] |
52,014,798 | https://en.wikipedia.org/wiki/Thermodesulforhabdus | Thermodesulforhabdus is an acetate-oxidizing bacterial genus from the order Syntrophobacterales. Up to now there is only on species of this genus known (Thermodesulforhabdus norvegica).
See also
List of bacterial orders
List of bacteria genera
References
Thermodesulfobacteriota
Monotypic bacteria genera
Bacteria genera | Thermodesulforhabdus | [
"Biology"
] | 81 | [
"Bacteria stubs",
"Bacteria"
] |
52,016,575 | https://en.wikipedia.org/wiki/Bibi-binary | The Bibi-binary system for numeric notation (, or abbreviated "") is a hexadecimal numeral system first described in 1968 by singer/mathematician Robert "Boby" Lapointe (1922–1972). At the time, it attracted the attention of André Lichnerowicz, then engaged in studies at the University of Lyon.
The notational system directly and logically encodes the binary representations of the digits in a hexadecimal (base sixteen) numeral. In place of the Arabic numerals 0–9 and letters A–F currently used in writing hexadecimal numerals, it presents sixteen newly devised symbols (thus evading any risk of confusion with the decimal system). The graphical and phonetic conception of these symbols is meant to render the use of the Bibi-binary "language" simple and fast.
The description of the language first appeared in Les Cerveaux non-humains ("Non-human brains"), and the system can also be found in Boby Lapointe by Huguette Long Lapointe.
Name
The central observation driving this system is that sixteen can be written as 2 to the power of 2, to the power of 2. As we use the term binary for numbers written in base two, Lapointe reasoned that one could also say "bi-binary" for base four, and thus "bibi-binary" for base 16. Its name may also be a pun, as the word bibi in French is slang for "me" or "myself"; various forms of word play were at the centre of Lapointe's artistic œuvre.
Pronunciation
In addition to unique graphical representations, Lapointe also devised a pronunciation for each of the sixteen digits. Using four consonants (HBKD) and four vowels (OAEI), one obtains sixteen combinations:
HO, HA, HE, HI, BO, BA, BE, BI, KO, KA, KE, KI, DO, DA, DE, DI.
To express any number, it suffices to enumerate the (hexadecimal) digits that make it up. For example: the number written as "2000" in decimal, which translates to "7D0" in conventionally-written hexadecimal, would in Bibi-binary be spoken aloud as "BIDAHO".
References
External links
Conversion en ligne décimal ↔ bibi-binaire (in French)
Hexadecimal numeral system
Positional numeral systems | Bibi-binary | [
"Mathematics"
] | 530 | [
"Numeral systems",
"Positional numeral systems"
] |
52,017,892 | https://en.wikipedia.org/wiki/William%20J.%20Evans%20%28chemist%29 | William J. Evans is a Distinguished Professor at the University of California, Irvine, who specializes in the inorganic and organometallic chemistry of heavy metals, specifically the rare earth metals (i.e. Sc, Y, and the lanthanides), actinides, and bismuth. He has published over 500 peer-reviewed research papers on these topics.
Evans was born in Madison, Wisconsin, and raised in Menomonee Falls, Wisconsin. He received a Bachelor of Science degree at the University of Wisconsin-Madison in 1969 where he did undergraduate research on pentaborane chemistry with Professor Donald F. Gaines. Subsequently, he attended the University of California, Los Angeles, where he obtained his PhD degree in 1973. His PhD research on the synthesis of metallocarboranes was supervised by Professor M. Frederick Hawthorne. He did postdoctoral research at Cornell University on the synthesis of transition metal phosphite complexes under the direction of Professor Earl L. Muetterties.
Evans began his independent research career in 1975 at the University of Chicago. He chose an area of research completely different from his training and experience, namely the chemistry of the rare-earth metals and actinides, with the central thesis that the special properties of these metals should lead to unique chemistry. He used exploratory synthesis to generate the new molecular species with the appropriate coordination environments to allow the special chemistry of these metals to be accessed. After receiving tenure at Chicago in 1982, he was recruited to the University of California, Irvine, where he has been a Professor since 1983. Among his recent accomplishments at UCI is the discovery of molecular species containing nine new rare earth and actinide oxidation states.
Evans is one of the few people to have received the American Chemical Society (ACS) Awards in both Inorganic Chemistry and Organometallic Chemistry. He has also received the Sir Edward Franklin Award and the Centenary Prize of the Royal Society of Chemistry, the Frank Spedding Award for Excellence in the Science and Technology of Rare Earths, the Terrae Rarae Award of the Tage der Seltenen Erden Society in Germany, the Richard C. Tolman Award of the Southern California Section of the ACS, a Special Creativity Extension Award from the National Science Foundation, the UCI Distinguished Faculty Award for Research, and the UCI Physical Sciences Outstanding Contributions to Undergraduate Education Award. He was also honored with UCI's highest faculty award, the Lauds and Laurels Outstanding Faculty Achievement Award. Recently, he was named Director of the Eddleman Quantum Institute at UCI and has been active in promoting interdisciplinary quantum science.
Research
Evans initially examined metal vapor methods to make new classes of lanthanide complexes in the 0 oxidation state. In efforts to characterize these products he identified the first crystallographically characterized lanthanide hydrides, [(C5H5)2(THF)Ln(μ-H)]2 (Ln = rare-earth metal), and the first soluble organometallic complex of samarium in the +2 oxidation state, (C5Me5)2Sm(THF)2. The latter complex demonstrated that lanthanide complexes could accomplish small molecule activation in unique ways, e.g. by reductive homologation of three CO molecules to (O2CC=C=O)2-. Desolvation of (C5Me5)2Sm(THF)2 formed the first bent metallocene with no other ligands, (C5Me5)2Sm.
Decamethylsamarocene, as it was called, was surprising because it was previously thought that large cyclooctatetraenyl rings were required with lanthanides and actinides to form two ring metallocenes. (C5Me5)2Sm was even more unusual in that it had a bent geometry instead of the parallel plane ferrocene-like structure expected for a simple ionic complex of a +2 ion with two large anionic cyclopentadienyl rings.
(C5Me5)2Sm provided the first evidence of a rare-earth metal dinitrogen complex, [(C5Me5)2Sm]2(μ-η2:η2-N2). More importantly, this was the first example of a coplanar arrangement of dinitrogen with two metal atoms. Previous M2N2 complexes had a butterfly geometry in which each metal could interact with a perpendicular N−N pi bond.
Subsequent studies of lanthanide-based dinitrogen reduction led to over forty crystallographically characterized examples of the formerly unprecedented planar M2(μ-η2:η2-N2) structures. These studies also led to the first examples of complexes of (N2)3- and (NO)2- radical anions. In collaboration with Professor Jeffrey R. Long, the (N2)3- complexes were found to constitute a new class of single-molecule magnets.
Evans' synthetic study of (C5Me5)2Sm led to the discovery a series of sterically crowded tris(pentamethylcyclopentadienyl) (C5Me5)3M complexes (M = rare earth and actinide). Previously, it was thought that three of these large ligands could not fit around any metal. This discovery was significant because of the metal-ligand bond lengths in these complexes were 0.1 Å longer than conventional distances. The sterically crowded (C5Me5)3M complexes exhibit reduction chemistry termed sterically induced reduction (SIR), as well as η1-alkyl reactivity.
Further exploration of dinitrogen reduction led to the synthesis of the first crystallographically characterizable molecular complexes containing Pr2+, Gd2+, Tb2+, Ho2+, Y2+, Er2+, and Lu2+ ions. These new lanthanide ions unexpectedly had 4fn5d1 electron configurations, and not the conventional 4fn+1 configuration generated by reduction of 4fn Ln3+ ions of Eu, Yb, Sm, Tm Dy, and Nd. The first molecular complexes of U2+ and Th2+ were also discovered in the Evans lab. In the Th2+ case, the complex contained the first example of any ion with a 6d2 electron configuration. This is the configuration expected for superheavy metal ions like Rf2+ and Db3+.
References
Year of birth missing (living people)
Living people
21st-century American chemists
American inorganic chemists
University of California, Irvine faculty
University of California, Los Angeles alumni
Chemists from Wisconsin | William J. Evans (chemist) | [
"Chemistry"
] | 1,375 | [
"American inorganic chemists",
"Inorganic chemists"
] |
52,018,554 | https://en.wikipedia.org/wiki/%CE%944-Tibolone | δ4-Tibolone (developmental code name ORG-OM-38), also known as 7α-methylnorethisterone or as 7α-methyl-17α-ethynyl-19-nortestosterone, is a synthetic androgen and progestin which was never marketed. The compound is a major active metabolite of tibolone, which itself is a prodrug of δ4-tibolone along with 3α-hydroxytibolone and 3β-hydroxytibolone (which, in contrast to δ4-tibolone, are estrogens). Tibolone and δ4-tibolone are thought to be responsible for the androgenic and progestogenic activity of tibolone, while 3α-hydroxytibolone and 3β-hydroxytibolone are thought to be responsible for its estrogenic activity.
See also
List of androgens/anabolic steroids
List of progestogens
References
{{DISPLAYTITLE:δ4-Tibolone}}
Abandoned drugs
Tertiary alcohols
Alkene derivatives
Ethynyl compounds
Anabolic–androgenic steroids
Estranes
Human drug metabolites
Ketones
Progestogens | Δ4-Tibolone | [
"Chemistry"
] | 262 | [
"Ketones",
"Functional groups",
"Drug safety",
"Human drug metabolites",
"Chemicals in medicine",
"Abandoned drugs"
] |
52,018,760 | https://en.wikipedia.org/wiki/IAS%2011 | The IAS 11 standard of International Accounting Standards set out requirements for the accounting treatment of the revenue and costs associated with long-term construction contracts. By their nature, construction activities and contracts are long-term projects, often beginning and ending in different accounting periods. Until its replacement with IFRS 15 in January 2018, IAS 11 helped accountants with measuring to what extent costs, revenue and possible profit or loss on the project are incurred in each period.
History
This is a timeline of IAS 11:
Content
How accounting revenue and costs are to be recognized depends first on whether the stage of completion of a project can be reliably measured. If this is the case, cost and revenue (including profit if any) can be recognized up to the percentage of completion during the current accounting period. If the stage of completion of a project cannot be reliably measured, the revenue can only be recognized up to the costs that have been incurred and any profit is only recognized at the end of the last accounting period. In the case a company is expecting to make a loss on the contract, this loss will be immediately recognized in the current accounting period.
References
International Accounting Standards
International Financial Reporting Standards
Civil engineering | IAS 11 | [
"Engineering"
] | 241 | [
"Construction",
"Civil engineering"
] |
52,019,270 | https://en.wikipedia.org/wiki/E-SCREEN | E-SCREEN is a cell proliferation assay based on the enhanced proliferation of human breast cancer cells (MCF-7) in the presence of estrogen active substances. The E-SCREEN test is a tool to easily and rapidly assess estrogenic activity of suspected xenoestrogens (singly or in combination). This bioassay measures estrogen-induced increase of the number of human breast cancer cell, which is biologically equivalent to the increase of mitotic activity in tissues of the genital tract. It was originally developed by Soto et al. and was included in the first version of the OECD Conceptual Framework for Testing and Assessment of Endocrine Disrupters published in 2012. However, due to failed validation, it was not included in the updated version of the framework published in 2018.
The E-SCREEN test
The E-SCREEN cell proliferation assay is performed with the human MCF-7 breast cancer cell line, an established estrogenic cell line that endogenously expresses ERα.
Human MCF-7 are cultivated in Dulbecco’s modified Eagle’s medium (DMEM) with fetal bovine serum (FBS) and phenol red as buffer tracer (culture medium), at 37 °C, in an atmosphere of 5% CO₂ and 95% air under saturating humidity. To accomplish the E-SCREEN assay the cells are trypsinized and plated in well culture plates. Cells are allowed to attach for 24 h, and the 4 seeding medium is then removed and replaced with the experimental culture medium (phenol red free DMEM with charcoal dextran treated fetal bovine serum -steroid-free-).
For assaying suspected estrogen active substances, a range of concentrations of the test compound is added to the experimental medium. In each experiment, the cells are exposed to a dilution series of 17β-estradiol (0.1 pM–1000 pM) for providing a positive control (standard dose-response curve), and treated only with hormone-free medium as a negative control. The bioassay ends on day 6 (late exponential phase) by removing the media from the wells and fixing the cells with trichloroacetic acid. After incubation (30 min; 4 °C) the trichloroacetic acid is removed by washing the plates under a gentle stream of cold water. After drying the plates at 40 °C the cell protein is stained with sulforhodamine B (SRB). After incubation (10 min) the dye is washed off with aqueous acetic acid (1%) and the plates are dried again at 40 °C. Finally, bound dye is solubilized with tris-buffer and incubated (20 min; 4 °C) and the absorbance is read at 492 nm.
The estrogenic activity results are expressed as mean ± standard deviation of the proliferative effect (PE), which represents the maximum proliferation induced by the test compound, and is the ratio between the highest cell number achieved with the sample or 17-β-estradiol and the cell number in the control group:
The estrogenic activity of a sample is evaluated by determining the relative efficacy of stimulation, called the relative proliferative effect (RPE%). The RPE compares the maximum proliferation induced by a sample with that induced by 17-β-estradiol:
The RPE can be used to define full agonists for ER, between 80% and 100% relative proliferation. Partial and weak agonists induce a relative cell proliferation from 25% up to 80%, or 10% to 25%, respectively.
Shortcomings/Limitations: One of the limitations for determining estrogenicity of chemicals by checking the proliferation of ER positive MCF-7 cell line is that mitogens other than estrogens can also influence cell proliferation thus rendering non-specific responses by chemicals.
The rationality for the use of this cell line is that:
It is a cell line of endocrine origin and is ER positive.
Expresses aromatase and 5α-reductase like other steroidogenic cells.
Possesses endogenous aromatase activity which converts androgens to estrogens.
Can elicit an estrogen-induced response involving both genomic and non-genomic pathways.
Mechanisms of action
The biological effects of estrogens (and xenoestrogens) are mediated through the estrogen receptor (ER). Estrogen receptors, which belong to a large superfamily of nuclear receptors, are transcription factors that induce transcription of target genes after binding to specific DNA sequences in their promoter.
There are two isoforms (ERα and ERβ):
The ERα is present in the uterus, and it is thought to drive the uterotropic response, since the uteri of the ERα "knock-out" mice do not respond to the estrogen administration.
The ERβ is present in organs such as prostate, hypothalamic nuclei and pituitary gland. It is also present, together with ERα in some human breast cancer cell lines.
The ER mediates most of the biological effects at the level of gene regulation by interacting through its site-specific DNA and with other coregulatory proteins. The classical mechanism of activation of ERs depends on ligand binding to the nuclear hormone receptors, after which the receptors dimerize and bind to estrogen response elements (EREs) located in the promoters of estrogen-responsive genes.
Nevertheless, basic scientific research shows that estrogens (and xenoestrogens) may also exert actions through nonnuclear steroid hormone receptors (e.g., membrane ERs), nonsteroid receptors (e.g., neurotransmitter receptors such as the serotonin receptor, dopamine receptor, norepinephrine receptor), orphan receptors (e.g., aryl hydrocarbon receptor (AhR)), enzymatic pathways involved in steroid biosynthesis and/or metabolism, and numerous other mechanisms that converge upon endocrine and reproductive systems.
Human health implications
Several reports suggest that xenoestrogens are clinically significant because they can mimic the effects of endogenous estrogen and directly or indirectly have been implicated in precocious puberty and other disorders of the reproductive system in wildlife and humans.
For example, many xenoestrogens are suspected to contribute to the development of breast cancer in women and prostate and testicular cancers in men, to reduce male fertility and to interact with the immune system.
Other tests to identify estrogens and/or xenoestrogens
In vivo tests (animal testing)
Uterotrophic Bioassay in Rodents: OECD Test Guideline 440
The gain of the number of human breast cancer cell is biologically identic to the rise, in tissues of the genital tract, of the mitotic activity such as the rodent endometrium. In the 1930s, a new screening test called the uterotrophic bioassay was created, but it was not until 1962 that was firstly normalized by an expert committee. This assay quantifies the addition of uterine wet weight or the intensification of uterotrophic response and, additionally, it measures vaginal cornification. The test estimates a chemical’s ability to evoke biological activities in accord with agonists or antagonists of endogenous estrogens (e.g. 17ß-estradiol); nevertheless, its use for agonists investigation is much more ordinary than for antagonist.
The uterus responds to estrogens in two ways:
An initial response is an addition of weight owing to water imbibition.
This response is succeeded by a weight gain as a result of tissue growth.
The uterus responses in rats and mice can be qualitatively compared.
Shortcomings/Limitations: The increase of uterine wet weight is not a specific estrogen respond. In addition, this assay has problems inherent to animal testing, is costly and time consuming.
Vitellogenin assay
Exposure to estrogens (xenoestrogens) may be also easily assessed in fish, reptiles or birds by measuring their vitellogenin (VTG) plasma levels. An example is that expression of the egg yolk precursor protein vitellogenin can be measured by the E-SCREEN test in juvenile brown trout. Usually, vitellogenin is only produced by female fish, because it is estrogen-dependent. Nevertheless, the synthesis of this protein in males and young fish can also occur, as xenoestrogens can also affect the hepatic receptors and activate it. Hence, a frequently used biomarker of exposure to estrogen active substances in the environment is the measurement of vitellogenin levels in male and juvenile trout.
In vitro test (quantitative bioassays using cells in culture)
Induction of estrogen-related proteins, such as pS2, prolactine or transforming growth factor β-3 (TGF β-3)
In several stable cell lines, it is possible to induce specific estrogen-related proteins. For example, in the human MCF-7 breast cancer cell line the protein pS2 is strongly up-regulated by estrogen. Induction of the pS2 protein can be detected already one hour after estrogen, or a given compound acting as an estrogen, is added to the cells.
Induction of reporter genes under control of estrogen-responsible elements
It is possible to generate an estrogen-responsive reporter cell line by introducing into a situable cell line specific DNA sequences that induce transcription of target genes of a readily measurable protein (the so-called reporter gene; e.g. firefly luciferase). That is an in vitro reporter gene assays detecting estrogen receptor (ER) activation. These bioassays form a group of the so-called CALUX (Chemically Activated LUciferase eXpression) bioassays. These systems are exemplified by the estrogen receptor ER CALUX bioassay consisting of the human T-47D breast tumor cell line expressing estrogen receptors (ER) endogenously together with an ER-specific Luciferase construct. A version of the ER CALUX bioassay, consisting of the human U2OS osterosarcoma cell line transfected with both ERα and ER-specific Luciferase construct is currently under validation to be included in OECD Test Guideline 455.
References
Other references
Xenoestrogens
Biological techniques and tools | E-SCREEN | [
"Biology"
] | 2,178 | [
"nan"
] |
52,019,329 | https://en.wikipedia.org/wiki/NGC%20291 | NGC 291 is a barred spiral galaxy in the constellation Cetus. It was discovered on September 27, 1864, by Albert Marth.
References
External links
0291
18640927
Cetus
Barred spiral galaxies
003140 | NGC 291 | [
"Astronomy"
] | 47 | [
"Cetus",
"Constellations"
] |
52,019,358 | https://en.wikipedia.org/wiki/NGC%20293 | NGC 293 is a barred spiral galaxy in the constellation Cetus. It was discovered on September 27, 1864 by Albert Marth.
References
External links
0293
18640927
Cetus
Barred spiral galaxies
Discoveries by Albert Marth
003195 | NGC 293 | [
"Astronomy"
] | 52 | [
"Cetus",
"Constellations"
] |
52,019,383 | https://en.wikipedia.org/wiki/NGC%20294 | NGC 294 is an open cluster located in the Small Magellanic Cloud in the constellation Tucana. It was discovered on April 11, 1834, by John Herschel, although it was possibly observed on September 5, 1826, by James Dunlop.
References
External links
0294
18340411
18260905
Tucana
Discoveries by James Dunlop
Small Magellanic Cloud
Open clusters | NGC 294 | [
"Astronomy"
] | 78 | [
"Tucana",
"Constellations"
] |
52,019,423 | https://en.wikipedia.org/wiki/NGC%20297 | NGC 297 is an elliptical galaxy in the constellation Cetus. It was discovered on September 27, 1864, by Albert Marth and is classified as type E3, based on galaxy morphological classification.
To date, according to redshift measurements, a current distance of 236 Mpc (~770 Mly) is given for NGC 297. This value falls within the range of Hubble distance values.
References
External links
0297
Elliptical galaxies
18640927
Cetus
003243
Discoveries by Albert Marth | NGC 297 | [
"Astronomy"
] | 104 | [
"Cetus",
"Constellations"
] |
52,019,619 | https://en.wikipedia.org/wiki/Penicillium%20imranianum | Penicillium imranianum is a species of fungus in the genus Penicillium.
Penicillium imranianum has been isolated from a man made solar saltern in Phetchaburi province in Thailand in 2010. The species information was deposited in NCBI, Mycobank and Index Fungorum. The species is present in TISTR with code 3655 and holotype EMCB-HF08 at RUBEM. The species is published as research article in Pakistan journal of Botany.
References
imranianum
Fungus species | Penicillium imranianum | [
"Biology"
] | 114 | [
"Fungi",
"Fungus species"
] |
52,020,068 | https://en.wikipedia.org/wiki/NGC%20298 | NGC 298 is a spiral galaxy in the constellation Cetus. It was discovered on September 27, 1864, by Albert Marth. NGC 298 is situated close to the celestial equator and, as such, it is at least partly visible from both hemispheres in certain times of the year. Given its B magnitude of 14.7, NGC 298 is visible with the help of a telescope having an aperture of 20 inches (500 millimetre) or more.
One supernova has been observed in NGC 298: SN 1986K (type II, mag. 16.5) was discovered by Thomas Schildknecht on 1 September 1986.
References
External links
0298
18640927
Cetus
Spiral galaxies | NGC 298 | [
"Astronomy"
] | 146 | [
"Cetus",
"Constellations"
] |
52,020,120 | https://en.wikipedia.org/wiki/NGC%20299 | NGC 299 is an open cluster of stars in the main body of the Small Magellanic Cloud – a nearby dwarf galaxy. It is located in the southern constellation of Tucana, just under 200,000 light years distant from the Sun. The cluster was discovered on August 12, 1834, by English astronomer John Herschel.
The cluster is around 25 million years old with 600 times the mass of the Sun. It spans a radius of . The metallicity of the cluster, what astronomers term the abundance of elements more massive than helium, is almost identical to that of the Sun. The cluster is old enough that the stellar winds from the most massive members has dispersed all of the original dust and gas. Hence, star formation has come to a halt. Two eclipsing binaries and one probable Be star have been identified, but the cluster is lacking any low-amplitude pulsating variables.
References
External links
Open clusters
Small Magellanic Cloud
0299
18340812
Tucana | NGC 299 | [
"Astronomy"
] | 200 | [
"Tucana",
"Constellations"
] |
52,020,220 | https://en.wikipedia.org/wiki/NGC%20301 | NGC 301 is a spiral galaxy located approximately 204 million light-years from the Solar System in the constellation Cetus. It was discovered in 1886 by Frank Muller.
See also
List of NGC objects (1–1000)
References
External links
SEDS
0301
3345
?
Cetus
Spiral galaxies | NGC 301 | [
"Astronomy"
] | 59 | [
"Cetus",
"Constellations"
] |
52,020,456 | https://en.wikipedia.org/wiki/Privatization%20%28computer%20programming%29 | Privatization is a technique used in shared-memory programming to enable parallelism, by removing dependencies that occur across different threads in a parallel program. Dependencies between threads arise from two or more threads reading or writing a variable at the same time. Privatization gives each thread a private copy, so it can read and write it independently and thus, simultaneously.
Each parallel algorithm specifies whether a variable is shared or private. Many errors in implementation can arise if the variable is declared to be shared but the algorithm requires it to be private, or vice versa.
Traditionally, parallelizing compilers could apply privatization to scalar elements only.
To exploit parallelism that occurs across iterations within a parallel program (loop-level parallelism), the need grew for compilers that can also perform array variable privatization. Most of today's compilers can performing array privatization with more features and functions to enhance the performance of the parallel program in general. An example is the Polaris parallelizing compiler.
Description
A shared-memory multiprocessor is a "computer system composed of multiple independent processors that execute different instruction streams". The shared memory programming model is the most widely used for parallel processor designs. This programming model starts by identifying possibilities for parallelism within a piece of code and then mapping these parallel tasks into threads.
The next step is to determine the scope of variables used in a parallel program, which is one of the key steps and main concerns within this model.
Variable scope
The next step in the model groups tasks together into bigger tasks, as there are typically more tasks than available processors. Typically, the number of execution threads that the tasks are assigned to, is chosen to be less than or equal to the number of processors, with each thread assigned to a unique processor.
Right after this step, the use of variables within tasks needs to be analyzed. This step determines whether each variable should be shared-by-all or private-to-each thread. This step is unique to shared-memory programming. (An alternative is message passing, in which all variables are private.)
According to their behavior, the variables are then categorized as:
Read-Only: when a variable is only read by all the parallel tasks.
Read/Write Non-conflicting: when a variable is read, written, or both by only one task. If the variable is not scalar, different elements may be read/written by different parallel tasks.
Read/Write Conflicting: when a variable is written by a task and may be read by another. If the variable is not scalar, different elements are read/written by different parallel tasks.
As it appears from their definition, Read/Write Conflicting variables introduce dependencies between different execution threads and hence prevent the automatic parallelization of the program. The two major techniques used to remove these dependencies are privatization and reduction. In reduction, each thread is provided with a copy of the R/W Conflicting variable to operate on it and produce a partial result, which is then combined with other threads' copies to produce a global result. Another technique similar to privatization is called expansion, in which a scalar variable is expanded into an array, which makes each thread access a different array element. If the variable to be expanded is an array, then expansion adds another dimension to the array.
Privatization
Dependencies – potential conflicts between different threads during execution – prevent parallelization, and these conflicts appear when we have Read/Write Conflicting variables. One technique to remove these conflicts is privatization. The basic principle involves making a private copy of a variable for each thread, rather than share one instance. This changes the category of the variable from Read/Write Conflicting to Read/Write Non-conflicting.
The actual local (private) instances of the Read/Write Conflicting variables are created at compile time, by allocating several areas of memory for the variables stored at different memory locations. The architecture of shared-memory multiprocessors helps, as threads share an address space.
There are two situations in which a variable can be described as privatizable:
When the variable is written before it is read by the same task during the original program's sequential order. In this case, if the task wrote to its private copy rather than the shared one, the conflict/dependency would be removed. The reason for this is that the program's sequential order will ensure that the value will be the one written by the same task, removing any conflicts that might occur by other threads accessing the same variable. See .
When the variable is read before it is written by the same task. The difference here is that the value the task is trying to read is one from a prior computing step in another task. But if each task wrote to its own private copy, any conflicts or dependencies would be solved during execution, as they would all read a value known ahead of time and then write their correct values on their own copies. See .
Because Read/Write Conflicting variables are the only category that prevents parallelization, there is no need explicitly to declare Read-only and Read/Write Non-conflicting variables as private. Doing so will not affect the correctness of the program, but may use more memory for unnecessary copies.
Limitations
Sometimes a variable can be neither privatized nor reduced to remove the read/write conflict. In these cases, the Read/Write Conflicting variable needs to be updated by different tasks at different points of time. See .
This problem can sometimes be solved by changing the scope of parallelism to explore a different parallel region. This might produce good results, as it is often that after reanalyzing the code, some Read/Write Conflicting variables may change to Read/Write Non-conflicting. If the variable still causes conflicts, the last resort is to declaring it as shared and protecting its access by some form of mutual exclusion, and providing synchronization if accesses to the variable needs to happen in a specified order to ensure correctness.
Arrays
Read/Write Conflicting variables can be scalar, or compound types such as arrays, matrices, structured types an so on. Privatization can be applied to both types of variables.
When applied to scalar variables, the additional space and overhead introduced by making the extra private copies per thread is relatively small, because scalars are small. However, applying privatization on arrays, matrices or other compound types is much more complex.
When dealing with arrays, the compiler tries to analyze the behavior of each array element separately and check for the order it is read and written. If each element is written before it is read in the same iteration, this array can be privatized. To do this, the compiler needs to further analyze the array to combine its accesses into sections. Moreover, the compiler should have extra functions, to be able to manipulate and deal with the array elements. For example, some array expressions may have symbolic terms, hence, to be able to privatize such array, the compiler needs to have some advanced symbolic manipulation functions.
Examples
Example 1
A variable can be privatized if each task will write to it before reading from it. In this case, it does not matter whether other threads are doing so. In the code below, the variable x is used to help swap three different pairs of variables. Because it is always written to before being read, it can be privatized.
//Sequential Code:
x = a;
a = b;
b = x;
x = c;
c = d;
d = x;
x = e;
e = f;
b = x;
This code cannot be made parallel without privatizing x. With x privatized, it can run on three different threads, each with its own private x:
//Parallel Code:
//Thread 1:
x[1] = a;
a = b;
b = x[1];
// Thread 2:
x[2] = c;
c = d;
d = x[2];
// Thread 3:
x[3]= e;
e = f;
b = x[3];
Example 2
Privatization is possible when a variable's value is known before it is used – even if it is written to by a different task. The code below demonstrates this. The variable x is written to in the middle of each task, but that value could be computed when the program was compiled. By making x private and defining it at the beginning of each task, the code can be run in parallel:
//Sequential Code:
x = 1;
y = x * 3;
x = 4;
z = y/x;
a = x * 9;
x = 3;
b = a/x;
c = x * 1;
x = 11;
d = c/x;
To make the sequential code above parallel, a few lines of code must be added so that x can be privatized:
//Parallel Code
//Thread 0:
x[0] = 1;
y = x[0] * 3;
x[0] = 4;
z = y/x[0];
//Thread 1:
x[1] = 4;
a = x[1] * 9;
x[1] = 3;
b = a/x[1];
//Thread 2:
x[2] = 3;
c = x[2] * 1;
x[2] = 11;
d = c/x[2];
Because of the extra code, this short example may not actually see much of a speed up. But in real-life, longer code this technique can greatly improve performance.
Example 3
Privatization fails is when a variable is written in one task and read in another, and the value is not known ahead of time. An example is summing the elements of an array. The sum is a shared variable and is read/written in each iteration of the loop.
In sequential code, this works fine. But if the iterations were each done in a different thread, the wrong sum would be calculated. In this case, privatization does not work. The sum cannot be made private because it relies on its value from the previous iteration.
//Sequential Code:
sum = 0;
for (i = 0; i < 100; i++)
sum += a[i];
This problem can be solved in part by loop unrolling. Because it does not matter which order the elements are added, the loop can be split into an arbitrary number of parts:
// Thread 0:
sum[0] = 0;
for (i[0] = 0; i[0] < 100; i[0] += 3)
sum[0] += a[i[0]];
// Thread 1:
sum[1] = 0;
for (i[1] = 1; i[1] < 100; i[1] += 3)
sum[1] += a[i[1]];
// Thread 2:
sum[2] = 0;
for (i[2] = 2; i[2] < 100; i[2] += 3)
sum[2] += a[i[2]];
// "Master" thread:
wait_for_all(thread[0], thread[1], thread[2]);
sum = sum[0] + sum[1] + sum[2];
OpenMP
OpenMP is a programming language that supports multiprocessor programming with shared memory. Because of this, Read/Write Conflicting variables will undoubtedly occur. In these cases, privatization can sometimes be used to allow parallel execution of the code.
Given the sequential code:
do i = 10, N - 1
x = (b(i) + c(i))/2
b(i) = a(i + 1) + x
enddo
For each iteration of the loop, x is written to and then read from. Because x is only a scalar variable, the loop cannot be executed in parallel because it would be overwritten in different threads, and b(i) would not always be assigned the correct value.
Equivalent parallelized code using privatization is:
!$omp parallel do shared(a, b) private(x)
do i = 10, N - 1
x = (b(i) + c(i))/2
b(i) = a(i + 1) + x
enddo
Because x is declared as private, each thread gets its own copy and the dependence is removed.
Comparison with other techniques
Normally, when a variable is Read/Write Conflicting, the solution will be declaring it as shared and protecting access to it by mutual exclusion, providing synchronization when needed. Because mutual exclusion slows things down, this technique is avoided as much as possible.
Thus, the compiler or programmer first checks whether the variable can be reduced. If it cannot, the next check is for privatization. Privatization trades space for time, so mutual exclusion can be a better option when memory is limited.
Compared to reduction, privatization requires one modelling step: merely to analyze the code to identify the privatizable variables. On the other hand, the two steps required by reduction are: identifying the reduction variable, and then parallelizing the reduction operator. By observing each of the two techniques, it is easy to tell what type of overhead each one adds to the parallel program; reduction increases the computation overhead while privatization increases the memory consumed by the program.
Compared to expansion, privatization has less memory overhead. The memory space needed for privatization is proportional to the number of processors, while in expansion, it is proportional to the number of iterations. Since the number of tasks is typically higher than the number of processors, the memory required by expansion is much larger than by privatization.
Changing the scope of parallelism can be done to explore a different parallel region. Doing so may sometimes greatly change the behavior of the variables. So reanalyzing the code and performing this technique may often change Read/Write Conflicting variables to be Non-conflicting.
See also
Parallel computing
Loop-level parallelism
References
Computer programming | Privatization (computer programming) | [
"Technology",
"Engineering"
] | 2,868 | [
"Software engineering",
"Computer programming",
"Computers"
] |
52,020,976 | https://en.wikipedia.org/wiki/Nicolas%20Corcione | Nicolas Corcione (born 1969) is, since 2013, the president of the Grupo Corcione Foundation, a non-profit organization that focuses on helping children and youth in situations of social vulnerability, through the pillars of education, sports, environmental protection and social contribution.
Corcione received his Master in Construction Project Management and his B.S. in Civil Engineering from the Worcester Polytechnic Institute (WPI). Nicolas is a member of the Panama Canal Authority Board of Directors, the WPI's Advisory Board and a Chairman of the Board at Grupo Corcione.
Corcione is a member and director of the Chamber of Commerce since 2005, Green Building Council Panama Chapter, ACOBIR-NAR Panama. EO Organization since 2005.
References
External links
- Panama Canal Authority
- Grupo Corcione Foundation
- Grupo Corcione
- Grupo Corcione Foundation gives donation to Martin Feuillet School in Chorrera
- Grupo Corcione Foundation bets on recycling on the Coastal Drive
1969 births
Living people
Civil engineers
Panamanian activists | Nicolas Corcione | [
"Engineering"
] | 221 | [
"Civil engineering",
"Civil engineers"
] |
52,022,163 | https://en.wikipedia.org/wiki/L%20band%20%28infrared%29 | In infrared astronomy, the L band is an atmospheric transmission window centred on 3.5 micrometres (in the mid-infrared).
References
Electromagnetic spectrum
Infrared imaging | L band (infrared) | [
"Physics",
"Astronomy"
] | 35 | [
"Astronomy stubs",
"Spectrum (physical sciences)",
"Electromagnetic spectrum"
] |
52,022,359 | https://en.wikipedia.org/wiki/M%20band%20%28infrared%29 | In infrared astronomy, the M band is an atmospheric transmission window centered on 4.8 micrometres (in the mid-infrared).
References
Electromagnetic spectrum
Infrared imaging | M band (infrared) | [
"Physics",
"Astronomy"
] | 35 | [
"Astronomy stubs",
"Spectrum (physical sciences)",
"Electromagnetic spectrum"
] |
52,022,736 | https://en.wikipedia.org/wiki/C14H18O8 | {{DISPLAYTITLE:C14H18O8}}
The molecular formula C14H18O8 may refer to:
Glucovanillin
Pungenin | C14H18O8 | [
"Chemistry"
] | 37 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
56,312,951 | https://en.wikipedia.org/wiki/List%20of%20personal%20finance%20software | Personal finance software can be used to track spending, create budgets, and plan for future expenses. Some software differs by feature support, software code and development transparency, mobile app features, import methods, Monetization model, privacy and data storage practices.
Risks
The use of expense tracking, budgeting, and other personal finance software carries some risk, most notably is due to the disclosure of a username, password, or other account credentials used to automatically synchronize banking information with an expense tracking application. Another significant area of risk is due to sensitive personal information that is stored anytime data is digitized. This risk may be compounded based on the security the software vendor has implemented as well as the availability of the data and where specifically it is stored (online or a local application). An often overlooked form of risk is due to the monetization model and privacy practices of the vendor or software provider, whether the application is "free" or fee based. Open source software is one way of potentially minimizing the risks of privacy and monetization related risks of data exposure.
The following is a list of personal financial management software. The first section is devoted to free and open-source software, and the second is for proprietary software.
Free and open-source personal financial management software
Proprietary personal financial management vendors and software
{| class="wikitable"
|+
!Name
!Spending Tracking
!Budgeting
!Investment Tracking
!Third-Party Bill Paying
!Operating Systems
!Mobile Support
!Software Type
!Direct Cost
!Other Monetization Models
!Description
|-
|Banktivity
|Yes
|Yes
|Yes
|Yes
|macOS
|iOS
|Stand alone
|Yearly Fee
|
|Personal finance software for Mac OS.
|-
|Mint
|Yes
|Yes
|Yes
|No
|Any
|iOS, Android
|Web-Based
|Free
|Financial product referrals
|Deprecated
|-
|Moneydance
|Yes
|
|Yes
|
|Any (JVM based)
|
|Stand alone
|
|
|
|-
|Moneyspire
|
|
|
|
|
|
|
|
|
|
|-
|MoneyWiz
|Yes
|Yes
|Yes
|No
|macOS
|iOS
|Stand alone
|Yearly Fee
|
|
|-
|More Money
|Yes
|No
|Yes
|No
|Windows
|
|Stand alone
|TBC
|
|
|-
|Personal Capital
|Manual or Automated
|
|Yes
|No
|Any
|
|Web-Based
|Free
|Fee-based in-house financial planning. Primarily a wealth management company that provides free services to non-clients.
|Offers financial advising for a fee, which establishes a client-fiduciary relationship that they claim makes them less incentivized to sell private client data as they are bound by law to act in their client's best interests.
|-
|Quicken
|Manual or Automated
|Yes
|Yes
|Yes
|Windows, macOS (limited)
|Android, iOS
|Stand alone or Web-Based for full functionality
|Yearly fee
|
|
|-
|You Need a Budget
|Manual or Automated
|Yes
|Yes
|No
|Any
|Android, iOS, Apple Watch, Alexa
|Web-Based
|Yearly or Monthly Fee
|
|Differentiates itself by providing budgeting advice.
|}
See also
Comparison of accounting software
List of free and open-source software packages
List of project management software
References
Personal financial software
Free accounting software | List of personal finance software | [
"Technology"
] | 693 | [
"Computing-related lists",
"Lists of software"
] |
56,313,570 | https://en.wikipedia.org/wiki/V357%20Muscae | V357 Muscae was a bright nova (Nova Muscae 2018) in the constellation Musca. It was discovered on January 14, 2018 by Rob Kaufman of Bright, Victoria, Australia with a magnitude of 7.0.
As well as being observed optically, the nova was also detected at radio wavelengths using the Australia Telescope Compact Array.
See also
List of novae in the Milky Way galaxy
References
Sources
PNV J11261220-6531086: nova (7 mag) in Musca (discovered by Rob Kaufman)
CBAT "Transient Object Followup Reports"
CBET 4472 "NOVA MUSCAE 2018" (access limited)
"Alert Notice 609: Nova Muscae 2018 - PNV J11261220-6531086"
Novae
20180114
Musca
Muscae, V357 | V357 Muscae | [
"Astronomy"
] | 179 | [
"Musca",
"Astronomical events",
"Constellations",
"Novae"
] |
56,314,301 | https://en.wikipedia.org/wiki/Surface%20treatment%20of%20PTFE | Polytetrafluoroethylene (PTFE), better known by its trade name Teflon, has many desirable properties which make it an attractive material for numerous industries. It has good chemical resistance, a low dielectric constant, low dielectric loss, and a low coefficient of friction, making it ideal for reactor linings, circuit boards, and kitchen utensils, to name a few applications. However, its nonstick properties make it challenging to bond to other materials or to itself.
A number of adhesion promotion methods have been developed to enhance PTFE bond strength. The primary methods currently used in industry are sodium etching and plasma etching. Results of ion beam treatment and laser surface roughening have also been reported in the literature, but do not have a significant presence as commercial processes.
Sodium etching
Wetting the surface of PTFE with commercially available solvents and liquid adhesives is virtually impossible. The exception to this is with special halogenated solvents that have a surface energy lower than PTFE, such as 3M's FC series solvents. These 3M solvents are, however, toxic and expensive. Additionally, even if wettability is acceptable, the PTFE will not form hydrogen bonds which are the primary source of adhesion strength. The PTFE surface therefore must be chemically modified to produce a surface which is capable of forming hydrogen bonds.
Early sodium etching solutions
Sodium etching of fluoropolymers has been used for decades to enhance bondability of PTFE. It is performed by immersion of the PTFE in a solution containing sodium followed by rinsing in alcohol and water. The process was originally performed by dissolving sodium metal in liquid ammonia. An alternative method was to form a complex with naphthalene, which was then dissolved in an ether such as tetrahydrofuran (THF). Both types of solutions carry risks to the user – both ammonia and THF are irritants, and both are flammable. At higher concentrations, THF is also a central nervous system depressant. In rats, the inhalation LC(50) (Lethal Concentration which kills 50% of test subjects) is 21,000 ppm for 3 hours. In humans, chronic effects have not been reported, but researchers using THF have developed severe occipital headaches and marked decreases in white blood cell counts.
Newer sodium etching solutions
More recently, glycol ethers (known as glymes) have come into use as carriers for the sodium naphthalene complex for PTFE etching. These glymes are ethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), and tetraethylene glycol dimethyl ether (tetraglyme). Glymes pose minimal or no health risks to the user, and the solutions do not require special storage conditions. When using glyme-based etchants, it is recommended that the etching process be performed at moderately elevated temperatures, about 50 °C. The elevated temperature causes the etchant to release more active sodium. It also lowers the viscosity of the etchant which enhances wetting of high aspect ratio features such as plated through-holes in printed circuit boards. Tests of diglyme-based etchants used at 50 °C have shown bond strength increases of 50% or more over room temperature etching.
Commercially available etchants today are primarily glyme-based. Rogers Corporation, a manufacturer of PTFE printed circuit board laminates, refers to Poly-Etch and FluoroEtch etchants in its Fabrication Guidelines, "Bonding PTFE Materials for Microwave Stripline Packages and Other Multilayer Circuits". Poly-Etch is a sodium naphthalene complex in tetraglyme, while Fluoro-Etch is a sodium naphthalide complex in diglyme Matheson, the manufacturer of Poly-Etch, also manufactures a monoglyme-based etchant called Poly-Etch W. Fulcrum Chemicals manufactures three different etchants called Natrex25, NatrexHighFp and Natrex64.
Sodium etching mechanism
The main effect of sodium etching is defluorination of the PTFE, stripping the fluorine molecules from the carbon backbone of the polymer. The fluorine-to-carbon atomic ratio (F/C ratio) is reduced from PTFE's theoretical ratio of 2.0 to 0.2 or less, after exposure to sodium naphthalene for 1 minute. The fluorine atoms are replaced with hydroxyl, carbonyl, and other functional groups which can form hydrogen bonds.
Topographically, chemical etching of PTFE with sodium results in a highly porous defluorinated layer. Superficially, it displays a characteristic "mud crack" appearance.
Wettability is improved significantly by the sodium etching process. The resultant surface has an increased surface energy, reported in one study as increasing from 16.4 mN/m to 62.2 mN/m. Contact angle is reduced from approximately 115 degrees to approximately 60 degrees.
Bond strengths
Relative to untreated PTFE, the sodium etching process has been well-documented to increase PTFE bond strengths significantly regardless of the test method (tensile, peel, lap shear) used to evaluate samples bonded with epoxy. Virtually all sodium etching bond strengths reported in academic journals predate the advent of glymes as carriers for sodium naphthalene complex.
In adhesion tests per ASTM D4541, in which an aluminum stud is bonded to the test surface and the stud is pulled in the direction normal to the surface, both surfaces of the failure interface were analyzed by X-ray photoelectron spectroscopy (XPS). F/C ratio was used as an indicator of the failure mode: F/C of zero corresponds to failure in the epoxy, while an F/C ratio near 2.0 indicates failure in the bulk PTFE. Intermediate F/C ratios indicate that failure occurred in the zone modified by the pretreatment.
Using this analysis method, failure in sodium etched samples is shown to be cohesive, occurring between the modified layer and the bulk PTFE and not between the epoxy and the treated PTFE. The adhesion properties therefore are assumed to be limited by the properties of the treated layer.
Sodium treated PTFE will degrade with exposure to UV radiation. Immediately after sodium treatment, the PTFE surface is dark brown. The weaker the etching solution, the lighter the color change and the weaker the bond will be. When exposed to UV radiation, the treated PTFE will gradually return to its original white color. Exposure to light, abrasion, heat and some oxidizing agents will also degrade the treated surface. The shelf life of treated surfaces may be as high as 3 to 4 months when stored below 5 °C in a dark oxygen- and moisture-free environment.
Plasma etching
In plasma etching, the PTFE is exposed to plasma, an electrically charged gas. Various gases may be used to generate the plasma.
Like chemical etching, plasma etching also defluorinates the PTFE, though not to the same degree. F/C ratios drop from 2.0 to 1.4 with an argon plasma, and to 1.8 with an oxygen plasma, and to 0.7-0.8 with an ammonia or hydrogen plasma.
Topographically, plasma treatment changes the surface morphology, with different morphologies resulting from different plasma gases used.
Contact angle decreased with treatment by some, but not all, plasma gases – in one study, argon plasma decreased the contact angle from about 105 degrees to 30 degrees after 1 hour of treatment, but oxygen plasma did not affect the contact angle.
Surface energy increased from 16.4 mN/m to 48.8 mN/m after ammonia plasma treatment and 36.8 mN/m after hydrogen plasma.
The aluminum stud pull-off test showed an increase from 31 N to about 200 N after either ammonia or hydrogen plasma treatment. XPS analysis of the plasma treated failure interface indicated cohesive failure between the modified layer and the bulk PTFE, similar to the chemically etched samples.
Comparison between chemical etching and plasma etching
Despite similar failure mechanisms in both sodium-etched and plasma-etched samples, sodium etching produces much higher bond strengths than plasma etching. Sodium-etched samples exhibited 4 to 5 times the strength of plasma-etched samples when tested in tension per ASTM D4541. When tested in peel, sodium-etched samples exhibited 3 to 12 times the peel strength of plasma-etched samples, depending on the type of plasma used.
One proposed explanation for the large difference in bond strengths is that chemical etching modifies the PTFE to a greater depth than plasma etching, increasing the tortuosity of the fracture path through the etched layer during adhesion testing. Another explanation for the large difference in bond strengths is that, in addition to defluorination, sodium etching results in cross-linking which may stabilize the modified PTFE interface, while plasma etching may cause chain scission (breakage of the PTFE polymer chain), since the C-C bond is weaker than the C-F bond. This polymer chain scission weakens the strength of the modified PTFE.
While plasma etching is not able to achieve adhesion increases approaching those of chemical etching, it does provide some improvement to PTFE adhesion over untreated PTFE.
Other PTFE surface treatments
Ion beam and laser treatments have also been studied as methods to improve PTFE adhesion. However, neither of these treatment modalities appears to be in use commercially.
Ion beam-treated PTFE exhibits significantly greater surface morphology changes than either chemical etching or plasma etching. Ion beam treatments with pure argon or pure oxygen result in minimal defluorination as determined by F/C ratio. Contact angle actually increased with ion beam treatment.
Peel strength with ion beam treatment increased as a function of the ion beam dose, achieving higher peel strengths than plasma-treated samples at doses above 5E15 ions/cm2.
The primary effect of ion beam treatment therefore is morphology modification, with little chemical effect. Longer ion beam treatment time is assumed to increase surface area for bonding, which in turn increases peel strength.
Laser surface roughening of PTFE has also been studied as a potential method for increasing bond strength to PTFE. In one study, Rauh et al. treated PTFE with a pulsed ArF laser at 193 nm. Multiple pulses were required to achieve a uniform roughness across the surface due to inhomogeneity of the untreated material. Peel test results using epoxy resin showed an increase from 0.9 N/cm to 8.9 N/cm.
References
Fluoropolymers
Biomaterials
Dielectrics
Dry lubricants
DuPont
DuPont products
Fluorocarbons
Plastics | Surface treatment of PTFE | [
"Physics",
"Biology"
] | 2,279 | [
"Biomaterials",
"Unsolved problems in physics",
"Materials",
"Medical technology",
"Dielectrics",
"Amorphous solids",
"Matter",
"Plastics"
] |
56,314,501 | https://en.wikipedia.org/wiki/C10H8S | {{DISPLAYTITLE:C10H8S}}
The molecular formula C10H8S (molar mass: 160.24 g/mol, exact mass: 160.0347 u) may refer to:
1-Naphthalenethiol
2-Naphthalenethiol | C10H8S | [
"Chemistry"
] | 65 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
56,314,867 | https://en.wikipedia.org/wiki/Lane%20centering | In road-transport terminology, lane centering, also known as lane centering assist, lane assist, auto steer or autosteer, is an advanced driver-assistance system that keeps a road vehicle centered in the lane, relieving the driver of the task of steering. Lane centering is similar to lane departure warning and lane keeping assist, but rather than warn the driver, or bouncing the car away from the lane edge, it keeps the car centered in the lane. Together with adaptive cruise control (ACC), this feature may allow unassisted driving for some length of time. It is also part of automated lane keeping systems.
Starting in 2019, semi-trailer trucks have also been fitted with this technology.
Comparison with other systems
Lane centering keeps the vehicle centered in the lane and almost always comes with steering assist to help the vehicle take gentle turns at highway speeds. Lane departure warning generates a warning when the vehicle crosses a line, while lane keeping assist helps the vehicle to avoid crossing a line, standardized in ISO 11270:2014.
In farming, "machine autosteer" is a technology which make automated steering and positioning of a machine in a landscape.
History
The first commercially available lane centering systems were based on off-the-shelf systems created by Mobileye, such as Tesla Autopilot and Nissan ProPilot, although Tesla switched to an in-house design when Mobileye ended their partnership. A handful of companies like Bosch, Delphi, ZF and Mobileye provide sensors, control units, or algorithms to car makers, who then integrate and refine those systems.
While not directly attributable to lane centering, crash rates on the Tesla Model S and Model X equipped with the Mobileye system were reduced by almost 40% while Tesla Autopilot was in use.
Operation
The lane detection system used by the lane departure warning system uses image processing techniques to detect lane lines from real-time camera images fed from cameras mounted on the automobile. Examples of image processing techniques used include the Hough transform, Canny edge detector, Gabor filter and deep learning. A basic flowchart of how a lane detection algorithm works to produce lane departure warning is shown in the figures.
Limitations
Features that differentiate systems include how well they perform on turns, speed limitations, and whether the system resumes from a stop.
Current lane centering systems rely on visible lane markings. They typically cannot decipher faded, missing, incorrect or overlapping lane markings. Markings covered in snow, or obsolete lane markings left visible, can affect the accuracy of the system.
GM's Super Cruise only works on known freeways that have been previously mapped, as it uses a combination of these maps and a precise GNSS position provided by Trimble's RTX GNSS correction service to determine if Super Cruise can be enabled or not. Most vehicles require the driver's hands to remain on the wheel, but GM's Super Cruise monitors the driver's eyes to ensure human attention to the road, and thus allows hands-free driving.
2018 Mobileye EyeQ4
Mobileye claimed in 2018 that 11 automakers would incorporate their EyeQ4 chip that enables L2+ and L3 autonomous systems; this would collectively represent more than 50% of the auto industry. Level 2 automation is also known as "hands off": this system takes full control of the vehicle (accelerating, braking, and steering). Level 3 is also known as "eyes off": the driver can safely turn their attention away from driving, e.g. the driver can text or watch a movie.
In 2018, the average selling price for the EyeQ4 chip to auto makers was about $450 U.S. dollars.
Nissan uses the EyeQ4 chip for their hands-off ProPilot 2.0 system.
Regulations
In the United States, in 2018, lane centering systems are not covered by any Federal Motor Vehicle Safety Standards, according to the NHTSA.
Territories such as the European union, Japan, Russia, Turkey, Egypt and the United Kingdom follow UNECE 79 regulation. In those territories following UNECE 79 regulation, automatically commanded steering functions are classified in several categories, for instance:
Category A function helps the driver at speed no greater than 10 km/h for parking maneuvering;
Category B1 function helps the driver to keep the vehicle within the chosen lane;
Category B2 function "keeps the vehicle within its lane by influencing the lateral movement of the vehicle for extended periods without further driver command/confirmation";
Category C and D and E are related to specific manoeuvres such as lane change
While all those functions are related to automated steering, lane centering is a concept close to the concept related to category B2, while LKA is closer to category B1.
Current international regulations require assistance systems to monitor that the driver keeps their hands on the steering wheel, with escalating warnings and eventual disengagement if they fail to do so. In North America, some manufacturers have "hands-off" systems which instead monitor whether the driver is paying attention to the road ahead.
Examples of level 2 automated cars
Because all of these vehicles also have adaptive cruise control that can work in tandem with lane centering, they meet the SAE standard for level 2 automation. Adaptive cruise control and lane centering are often only available in more expensive trim levels rather than just the base trim. An example is the Hyundai Kona EV, which only has adaptive cruise control available on the "ultimate" edition.
Nissan ProPilot
Nissan ProPilot is based on Mobileye technology and assists with acceleration, steering and braking input under single lane highway driving conditions. ProPilot keeps the car centered in the lane and will deactivate below 31 mph if not tracking a car in front of it. Adaptive cruise control handles stop-and-go traffic if stopped for less than 4 seconds and helps maintain a set vehicle speed and maintain a safe distance between the vehicle ahead. ProPilot, which can follow curves, uses a forward-facing camera, forward-facing radar and other sensors. A traffic sign recognition system provides drivers with the most recent speed limit information detected by a camera on the windshield, in front of the rear-view mirror.
In a review by ExtremeTech, ProPilot worked well in 1,000 miles of testing and only on some twisty sections did it require driver intervention. During Euro NCAP 2018 testing, ProPilot failed some tests as did all other systems tested. Consumer Reports indicates that ProPilot is especially helpful in stop and go traffic.
Honda Sensing/AcuraWatch
Honda Sensing and AcuraWatch are a suite of advanced driver assistance features including Lane Keeping Assist System (LKAS) which helps keep the vehicle centered in a lane, by applying mild steering torque if the vehicle is deviating from the center of a detected lane with no turn-signal activation by the driver. The Lane Keeping Assist System (LKAS) does not work at speeds below . However, certain vehicles equipped with Traffic Jam Assist (TJA) will have the system take over the lane-keeping task when the speed falls below until a stop, and it will automatically switch to Lane Keeping Assist System (LKAS) when the speed exceeds .
The Honda Sensing and AcuraWatch packages also include:
Adaptive cruise control with Low-Speed Follow
Traffic-sign recognition
Auto high beam
Blind Spot Information System
2018 evaluation by IIHS
Quote from David Zuby, chief research officer at the American Insurance Institute for Highway Safety:
The report indicated that only the Tesla Model 3 stayed within the lane on all 18 trials.
Quote from the report:
See also
Advanced driver-assistance system
Hands-free driving
References
External links
Comma.ai open source lane centering system
Real-world analysis of fatal run-out-of-lane crashes using the national motor vehicle crash causation survey to assess lane keeping technologies Real-World Analysis of Fatal Run-Out-of-Lane Crashes Using the National Motor Vehicle Crash Causation Survey to Assess Lane Keeping Technologies
News
Which Cars Have Autopilot for 2019?
Not much faith in lane-centering technology Oct 2019
Cars with Autopilot in May 2019
Why Level 3 automated technology has failed to take hold. July 21, 2019
Comparisons
Tesla's Autopilot battles BMW's driver-assist Youtube Dec 27, 2019
Advanced driver assistance systems
Warning systems | Lane centering | [
"Technology",
"Engineering"
] | 1,694 | [
"Self-driving cars",
"Safety engineering",
"Measuring instruments",
"Automotive engineering",
"Warning systems"
] |
56,315,066 | https://en.wikipedia.org/wiki/Rectangular%20polyconic%20projection | The rectangular polyconic projection is a map projection was first mentioned in 1853 by the United States Coast Survey, where it was developed and used for portions of the U.S. exceeding about one square degree. It belongs to the polyconic projection class, which consists of map projections whose parallels are non-concentric circular arcs except for the equator, which is straight. Sometimes the rectangular polyconic is called the War Office projection due to its use by the British War Office for topographic maps. It is not used much these days, with practically all military grid systems having moved onto conformal projection systems, typically modeled on the transverse Mercator projection.
Description
The rectangular polyconic has one specifiable latitude (along with the latitude of opposite sign) along which scale is correct. The scale is also true on the central meridian of the projection. Meridians are spaced such that they meet the parallels at right angles in equatorial aspect; this trait accounts for the name rectangular.
The projection is defined by:
where:
λ is the longitude of the point to be projected;
φ is the latitude of the point to be projected;
λ is the longitude of the central meridian,
φ is the latitude chosen to be the origin along λ;
φ is the latitude whose parallel is chosen to have correct scale.
To avoid division by zero, the formulas above are extended so that if φ = 0 then x = 2A and y = −φ. If φ= 0 then A = (λ − λ).
See also
List of map projections
American polyconic projection
References
External links
Mapthematics page describing the rectangular polyconic projection.
Map projections | Rectangular polyconic projection | [
"Mathematics"
] | 332 | [
"Map projections",
"Coordinate systems"
] |
56,315,222 | https://en.wikipedia.org/wiki/Tethered%20flight%20test | A tethered flight test is a type of flight testing where a machine is connected by a tether to the ground. Tethered testing may be used when motion through the atmosphere is not required to sustain flight, such as for airship; vertical take-off and landing (VTOL), rotary wing or tiltwing aircraft (tethered hovering); or for tests of certain rockets, such as vertical takeoff, vertical landing (VTVL). Fixed wing scale models can be tested on a tether in a wind tunnel, simulating motion through the atmosphere.
History
Numerous vertical take-off and landing (VTOL) aircraft conducted their initial flights while tethered. Early vertical flights of the Short SC.1, an early experimental aircraft that was the first British fixed-wing VTOL aircraft as well as the first one to transition between vertical and horizontal flight modes. For these flights, a custom-built gantry was developed that accommodated only a limited amount of freedom, up to 15 ft vertically and 10 ft off-centre in any direction, vertical velocity was also restricted to less than 10 ft/second; progressive arresting of the aircraft occurred beyond these limitation. It would take off from a grid platform positioned 6 ft above the ground itself in order to circumvent the ground effect phenomenon; considerable effort on the part of Shorts had been made during development of a suitable platform to eliminate the negative impact of ground effect and was redesigned several times. The gantry facility was used for ab initio training and familiarisation purposes for the first 8 pilots to fly the SC.1.
Insight from the SC.1 heavily influenced the Hawker Siddeley P.1127, the forerunner to the Hawker Siddeley Harrier VTOL fighter. Its initial flights were also performed while tethered; such flights were largely conducted so that test pilots could familiarise themselves with the aircraft's controls in hover in a less risky environment. As confidence in the aircraft's handling grew, tethered flights without the aid of its onboard auto-stabiliser system were conducted. Finally, on 19 November 1960, the first un-tethered free-flight hover of a P.1127 took place; flight testing of the type proceeded over the rest of the decade ahead of the first production aircraft being introduced to service in 1969.
Numerous VTOL aircraft that would eventually be cancelled mid-development underwent tethered test flights. A pair of prototype EWR VJ 101 fighters were produced, the first performing its first hovering flight on 10 April 1963. Prior to this, the VJ 1010's propulsion concept had been evaluated on a specially-produced test rig, often informally referred to as the Wippe (seesaw), during the early 1960s; it incorporated a rudimentary cockpit fixed upon a horizontal beam, which had a "lift" engine mounted vertically at the centre, for the purpose of performing preliminary single-axis tests of the control system. A second "hover rig" was later assembled, possessing the skeletal fuselage of the VJ 101C along with a total of three Rolls-Royce RB108 engines installed in the approximate positions that they would occupy in the final flight-capable version and capable of lifting the test rig. Starting in May 1961, initial testing was conducted from a telescopic column, in March 1962, the new rig conducted its first "free flight" successfully.
The experimental Dassault Balzac V, a forerunner to the larger Dassault Mirage IIIV, was another experimental VTOL aircraft. The Balzac commenced tethered hover flights on 12 October 1962, and achieved the first free-hover only six days later; flight testing of the type ended in September 1965 following an accident. The Yakovlev Yak-36, an experimental VTOL aircraft developed in the Soviet Union as a forerunner to the Yakovlev Yak-38 production carrier aircraft, was also subject to a number of tethered flights in advance of freely hovering. During early development work for the Ryan X-13 Vertijet, test rigs were repeatedly flown via remote control while tethered.
References
Citations
Bibliography
Hirschel, Ernst Heinrich., Horst Prem and Gero Madelung. Aeronautical Research in Germany: From Lilienthal until Today. Springer Science & Business Media, 2012. .
Jackson, Paul. Modern Combat Aircraft 23 - Mirage. London: Guild Publishing, 1985. .
Jefford, C.G., ed. The RAF Harrier Story. London: Royal Air Force Historical Society, 2006. .
Lean D. and Chinn H.W. Review of General Operating Experience with a Jet-Lift VTOL Research Aircraft (Short S.C.l.) (Aeronautical Research Council Current Papers CP No. 832). London: HMSO, 1965. Retrieved: 2 December 2008.
Mason, Francis K. The Hawker P.1127 and Kestrel (Aircraft in Profile 93). Leatherhead, Surrey, UK: Profile Publications Ltd., 1967.
Rogers, Mike. VTOL: Military Research Aircraft. New York: Orion Books, 1989. .
External links
Aerospace system testing | Tethered flight test | [
"Engineering"
] | 1,050 | [
"Aerospace system testing",
"Aerospace engineering"
] |
56,315,321 | https://en.wikipedia.org/wiki/Aquaglyceroporins | Aquaglyceroporins are recognized as a subset of the aquaporin family of proteins which conduct water, glycerol and other small, uncharged solutes. They are the only mammal proteins which are able to permeate glycerol through the plasma membrane. Aquaglyceroporins are found in many species including bacteria, plants and humans. Because of their ubiquitous nature they are important in agriculture as well as medicine. They have been identified as a possible source of metalloid contamination in agriculture as aquaglyceroporins were have been shown to conduct As(III) and Sb(III) in yeast and could be a possible source of metalloids entering the food sources of humans.
Clinical Significance
Aquaporin-7 has been the subject of study in adipose tissue as it is a major source of circulating glycerol in the mammalian metabolism. The dysregulation of Aquaporin-7 has been associated with obesity in humans and has been associated with the regulation of adipocyte metabolism.
Aquaporin-9 a major glycerol channel in mouse erythrocytes has been found to contribute to the intraethrocytic stages of malarial infection and the dysfunction of the protein has been found to increase the survival in clinical studies involving mice.
References
Protein families
Membrane proteins | Aquaglyceroporins | [
"Biology"
] | 275 | [
"Protein families",
"Protein classification",
"Membrane proteins"
] |
56,315,819 | https://en.wikipedia.org/wiki/Arithmetic%20billiards | In recreational mathematics, arithmetic billiards provide a geometrical method to determine the least common multiple and the greatest common divisor of two natural numbers. It makes use of reflections inside a rectangle which has sides with length of the two given numbers. This is an easy example of trajectory analysis used in dynamical billiards.
Arithmetic billiards can be used to show how two numbers interact. Drawing squares within the rectangle of length and width of one allows a reader to find information of the two numbers. Coprime integers will interact with every unit square within the rectangle.
Properties
Arithmetic billiards is a name given to finding both the least common multiple (LCM) and the greatest common divisor (GCD) of two integers using a geometric method. It is named this way due to looking similar to the movement of a billiard ball.
A rectangle is drawn with a base of the larger number, and height of the larger number. Constructing a path at the bottom left corner at 45° angle, keep the line going until it hits a side of the rectangle. Every time that the path hits a side, it reflects with the same angle (the path makes either a left or a right 90° turn). Eventually (i.e. after a finite number of reflections) the path hits a corner and there it stops.
If one side length divides the other, the path is a zigzag consisting of one or more segments.
Else, the path has self-intersections and consists of segments of various lengths in two orthogonal directions.
In general, the path is the intersection of the rectangle with a grid of squares (oriented at 45° with respect to the rectangle sides).
Features
For the rectangle, shaped similar to a billiard table, we give and as the side lengths. This can be divided into unit squares. The least common multiple is the number of unit squares crossed by the arithmetic billiard path or, equivalently, the length of the path divided by .
Suppose that none of the two side lengths divides the other. Then the first segment of the arithmetic billiard path contains the point of self-intersection which is closest to the starting point. The greatest common divisor is the number of unit squares crossed by the first segment of the path up to that point of self-intersection. The path goes through each unit square if and only if and are coprime integers - they have a GCD of 1.
The number of bouncing points for the arithmetic billiard path on the two sides of length equals , and similarly for the two sides of length . In particular, if and are coprime, then the total number of contact points between the path and the perimeter of the rectangle (i.e. the bouncing points plus starting and ending corner) equals .
The ending corner of the path is opposite to the starting corner if and only if and are exactly divisible by the same power of two (for example, if they are both odd), else it is one of the two adjacent corners, according to whether or has more factors in its prime factorisation. The path will be symmetric if the starting and the ending corner are opposite. The path will be point symmetric in conjunction
with the center of the rectangle, else it is symmetric with respect to the bisector of the side connecting the starting and the ending corner.
The contact points between the arithmetic billiard path and the rectangle perimeter are evenly distributed: the distance along the perimeter (i.e. possibly going around the corner) between two such neighbouring points equals . Setting coordinates in the rectangle such that the starting point is and the opposite corner is . Then any point on the arithmetic billiard path which has integer coordinates has the property that the sum of the coordinates is even (the parity cannot change by moving along diagonals of unit squares). The points of self-intersection of the path, the bouncing points, and the starting and ending corner are exactly the points in the rectangle whose coordinates are multiples of and such that the sum of the coordinates is an even multiple of .
Proof
There are a few ways to show a proof of arithmetic billiards.
Consider a square with side . By displaying multiple copies of the original rectangle (with mirror symmetry) we can visualise the arithmetic billiard path as a diagonal of that square. In other words, we can think of reflecting the rectangle rather than the path segments.
It is convenient to rescale the rectangle dividing and by their greatest common divisor, operation which does not alter the geometry of the path (e.g. the number of bouncing points).
The motion of the path is “time reversible”, meaning that if the path is currently traversing one particular unit square
(in a particular direction), then there is absolutely no doubt from which unit square and from which direction it just came.
One generalisation
If we allow the starting point of the path to be any point in the rectangle with integer coordinates, then there are also periodic paths unless the rectangle sides are coprime. The length of any periodic path equals .
Usage
Arithmetic billiards have been discussed as mathematical puzzles by both Hugo Steinhaus and Martin Gardner. Arithmetic billiards is sometimes used by teachers to show GCD and LCM. They are sometimes referred to by the name 'Paper Pool' due to a common version of billiards called pool. They have been used as a source of questions in mathematical circles.
External links
A website version drawing the lines themed around billiards
References
Arithmetic dynamics
Cue sports
Geometry | Arithmetic billiards | [
"Mathematics"
] | 1,141 | [
"Recreational mathematics",
"Arithmetic dynamics",
"Geometry",
"Number theory",
"Dynamical systems"
] |
56,316,763 | https://en.wikipedia.org/wiki/Testing%20of%20advanced%20thermoplastic%20composite%20welds | Welding of advanced thermoplastic composites is a beneficial method of joining these materials compared to mechanical fastening and adhesive bonding. Mechanical fastening requires intense labor, and creates stress concentrations, while adhesive bonding requires extensive surface preparation, and long curing cycles. Welding these materials is a cost-effective method of joining concerning preparation and execution, and these materials retain their properties upon cooling, so no post processing is necessary. These materials are widely used in the aerospace industry to reduce weight of a part while keeping strength.
For many industries there are codes and standards that need to be followed when being implemented into service. The quality of the welds made on these materials are important in ensuring people receive safe products. There are not codes made specifically for the welding of advanced thermoplastic composite welds, so the codes for adhesive bonding of plastics and metals are slightly altered, and used in order to properly test these materials. Even though the joining method is different these materials have mechanical requirements they need to meet.
Weld testing and analysis
There are several mechanical properties that need to be tested to ensure the quality of welds. The testing methods talked about in this article will be referenced from the ASTM adhesive bonding standards. The properties needed to be tested are shear strength, fracture toughness, and fatigue properties. Optical microscopy is also often done to look for weld defects.
Testing for shear strength
According to ASTM D1002 The specimens tested will be configured as lap joints. They will need to be sectioned in a way that they can fit in the grips used for the tensile testing. The length of the overlap for the lap joint is determined by the thickness of the material, the yield point of the metal, and the value that is 50% of the estimated average shear strength in an adhesive bond, but for the purpose of this article it will be specified for a welded joint. The code also specifies the required capabilities of the machine used to test the shear strength. The breaking load of the specimens must fall between 15 and 85 percent of the full scale capabilities of the apparatus. For thermoplastic composites these machines need to be able to maintain a loading rate of 80–100 kg/cm2. The jaws of the machine must align with test specimen so as soon as the test gets started the long axis of the test specimen will be aligned with the direction of the applied tension. The machines grip on the test specimen must be 63 mm (2.5 in). The code specifies what needs to be recorded from the test such as material used, material thickness and other necessary sample measurements, and material properties. ASTM also governs on precision of testing, and avoiding bias in the results.
Fatigue strength
ASTM D3166 specifies fatigue testing methods for metal to metal adhesive joints. It references ASTM D1002 for creating test specimens. The testing machine must be capable of applying a sinusoidal cyclic axial load. The cycle rate and type of equipment can influence the results of the tests being run. 1800 cycles/minute are recommended unless otherwise specified. Tests are generally run at ambient temperature and humidity which is specified at 50% relative humidity ±4%, and 23 °C ±1.1 °C. At least 5 S-N curves need to be generated for a welded joint to give a usable range of cyclical loads on the material. The loads need to be varied from a minimal value that is ideally above 2000 cycles, to a load with 10% of the materials max strength.
Fracture toughness
Impact testing is done to test the fracture toughness of the joints welded. ASTM D5041 is used for reference when doing impact tests on advanced thermoplastic composites. Impact tests can get data for figuring out how much energy is needed to break the material, and it can also shed light on modes of failure for a certain joint. The testing machine needs to be something that moves at a constant speed before impact, it needs to be able to give a force readout on impact, generally a wedge is used as the impact tool, along other requirements specified by the code. The code calls for the tests to be done at ambient lab conditions, but depending on the application of the material this may change. Standard speed of testing for impacts is 127 mm/min, where the standard chart speed is 250 mm/min.
Optical microscopy
Optical microscopy is a necessary testing method in order to observe the quality of the weld joint. There are defects that can occur during welded that can weaken the joint or cause stress concentrations. Voids can occur during processes such as induction, ultrasonic, and resistance welding, so visual inspection is important to ensuring a quality joint, while developing weld procedures, and for using parts for service. Inspection can be done with the naked eye, an optical microscope, and more high-powered devices such as a scanning electron microscope (SEM). Taking a cross section of the welded joint will allow the joint to be inspected for defects.
Non-destructive Testing of Thermoplastic Composite Welds
Many of the nondestructive testing (NDT) methods available for testing of thermoplastic composite base materials can be used for welds in thermoplastic composites as well. In some cases, modifications are necessary. International standards like EN 13100-1, 13100-2, 13100-3 & 13100-4 govern inspection of the base materials. While these standards were not necessarily developed specifically for the welds in said materials, the physical principles are often still applicable.
The methods include:
Visual Inspection (VT) is typically the first option for any attempt at NDT, being the least expensive, as it requires the least specialized training and usually few if any special tools. Defects on the surfaces of thermoplastic composite welds can be detected visually if they are of sufficient size. Weld defects such as misalignment, porosity, lack of fusion and degradation of the matrix and/or fibers may be visually apparent. Subsurface defects may not be visible, unless the composite matrix was nearly transparent and the embedded fibers did not obscure them.
Ultrasonic testing (UT) can offer detailed NDT information for welded thermoplastic composites. Tests can be done with shear wave or transverse waves, though the composite materials often attenuate the signals significantly and care must be taken to account for this. Contact methods using either manual or automated transducers coupled to the part being inspected or non-contact methods using water immersion or a bubbler (i.e. a continuous stream of water through which the ultrasound passes) can be effective if designed and calibrated properly. Amplitude of reflection data may be used to generate B-scan or C-scan images, which can show the materials being welded at various, discrete depths or cross sections, a capability not available with traditional radiographic methods. Ultrasound can detect delaminations, lack of fusion, porosity, voids, inclusions and other defects mostly regardless of their orientation. Deterring factors include that the method is time consuming and the data are open to some interpretation, requiring skilled technician to perform and interpret the test.
Radiographic testing (RT) can be performed in several ways. Typically low energies are required for testing of composites in order to see any detail, which restricts the radiation sources to be used to x-ray types rather than gamma sources like Ir-192 or Cobalt-60, which tend to have higher energy levels. Data may be recorded either on film or digitally, using specially developed screens for detecting and saving an image than can be manipulated later with the proper software and hardware. Because radiographic testing relies on differences in material density to provide an image, resolution of fibers like carbon from the thermoplastic matrix is not always very high, since the density of the plastic does not differ much from that of the carbon or glass filaments. For digital imaging, the lack of contrast may be partially addressed after the radiographic images are taken, using digital imaging software. Radiography can detect porosity, voids and possibly differences in fiber density or orientation in the composite matrix due to the welding process. Lack of fusion may not be visible by RT unless it is perpendicular to the direction of the source of radiation.
Computed Tomography (CT), a subset of radiographic testing, is proving useful for the inspection of thermoplastic composite welds. CT involves the computerized building of a 3-D image using X-rays taken from numerous, incremental angles. It is particularly useful for the determination of fiber orientation in welds of glass reinforced composites.
Thermography involves testing the part for discontinuities that can be seen by an infrared camera when the part is heated or cooled. It offers a significant improvement on some of the more traditional NDT methods in that it can be used on large areas of, for example, airplane parts or storage tanks.
Eddy Current testing (ET) has been found to be useful for characterizing the nature of fibers and their orientation in certain composite materials, particularly those with conductive reinforcing fibers. It would not be useful for composites reinforced with glass or aramid fibers, for example, as no currents can be induced in these insulating materials. Much higher magnetic field frequencies are used to generate the eddy currents used for testing plastic composites than are typically used for metals. Though delaminations in the material were either undetectable or nearly so, more recent research has found that by induction heating the part in addition to exciting an alternating magnetic field, some delaminations could also be detected in CFRP.Laser Shearography involves accurately measuring perturbations in the surfaces of a (usually thin) part under load or strain with the aid of lasers scanning across the surface being evaluated. Voids, pores, delaminations and other defects in composite welds can be detected by this method.
Acoustic Emission testing provides qualitative information on the presence and potential growth of defects such as cracks and delaminations in welded composite materials. Typically this method is used to help narrow down the locations(s) of defects in large structures before using a more precise NDT method such as radiography or ultrasonic testing to help localize and characterize the nature of the defect.
References
Materials testing
Materials science
Plastic welding
Welding | Testing of advanced thermoplastic composite welds | [
"Physics",
"Materials_science",
"Engineering"
] | 2,107 | [
"Applied and interdisciplinary physics",
"Welding",
"Materials science",
"Materials testing",
"Mechanical engineering",
"nan"
] |
56,318,054 | https://en.wikipedia.org/wiki/Buglossoporus%20magnus | Buglossoporus magnus is a rare species of poroid fungus in the family Fomitopsidaceae. Recorded from only three locations in old growth lowland rainforest of Peninsular Malaysia, it is considered a vulnerable species by the IUCN.
The large, orange-pinkish fruit bodies of the fungus–measuring wide–were discovered by British mycologist E.J.H. Corner. He noted "I met this massive fungus but once, on a large, slowly decomposing, fallen trunk that I had often passed by in previous years." The holotype specimen was found in a forest reserve in Bukit Timah, Singapore. Although the original observation of the fungus is dated to 1940, it was not officially described as a new species until 1984.
See also
List of fungi by conservation status
Largest fungal fruit bodies
References
Fungi of Asia
Fomitopsidaceae
Fungi described in 1984
Fungus species | Buglossoporus magnus | [
"Biology"
] | 181 | [
"Fungi",
"Fungus species"
] |
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