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**Sphalerite**
Sphalerite:
Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula (Zn,Fe)S. It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite (and other sulfides), calcite, dolomite, quartz, rhodochrosite, and fluorite.German geologist Ernst Friedrich Glocker discovered sphalerite in 1847, naming it based on the Greek word sphaleros, meaning "deceiving", due to the difficulty of identifying the mineral.In addition to zinc, sphalerite is an ore of cadmium, gallium, germanium, and indium. Miners have been known to refer to sphalerite as zinc blende, black-jack, and ruby blende. Marmatite is an opaque black variety with a high iron content.
Crystal habit and structure:
Sphalerite crystallizes in the face-centered cubic zincblende crystal structure, which named after the mineral. This structure is a member of the hextetrahedral crystal class (space group F43m). In the crystal structure, both the sulfur and the zinc or iron ions occupy the points of a face-centered cubic lattice, with the two lattices displaced from each other such that the zinc and iron are tetrahedrally coordinated to the sulfur ions, and vice versa. Minerals similar to sphalerite include those in the sphalerite group, consisting of sphalerite, colaradoite, hawleyite, metacinnabar, stilleite and tiemannite. The structure is closely related to the structure of diamond. The hexagonal polymorph of sphalerite is wurtzite, and the trigonal polymorph is matraite. Wurtzite is the higher temperature polymorph, stable at temperatures above 1,020 °C (1,870 °F). The lattice constant for zinc sulfide in the zinc blende crystal structure is 0.541 nm. Sphalerite has been found as a pseudomorph, taking the crystal structure of galena, tetrahedrite, barite and calcite. Sphalerite can have Spinel Law twins, where the twin axis is [111].
Crystal habit and structure:
The chemical formula of sphalerite is (Zn,Fe)S; the iron content generally increases with increasing formation temperature and can reach up to 40%. The material can be considered a ternary compound between the binary endpoints ZnS and FeS with composition ZnxFe(x-1)S, where x can range from 1 (pure ZnS) to 0.6.
Crystal habit and structure:
All natural sphalerite contains concentrations of various impurities, which generally substitute for zinc in the cation position in the lattice; the most common cation impurities are cadmium, mercury and manganese, but gallium, germanium and indium may also be present in relatively high concentrations (hundreds to thousands of ppm). Cadmium can replace up to 1% of zinc and manganese is generally found in sphalerite with high iron abundances. Sulfur in the anion position can be substituted for by selenium and tellurium. The abundances of these impurities are controlled by the conditions under which the sphalerite formed; formation temperature, pressure, element availability and fluid composition are important controls.
Properties:
Physical properties Sphalerite possesses perfect dodecahedral cleavage, having six cleavage planes. In pure form, it is a semiconductor, but transitions to a conductor as the iron content increases. It has a hardness of 3.5 to 4 on the Mohs scale of mineral hardness.It can be distinguished from similar minerals by its perfect cleavage, its distinctive resinous luster, and the reddish-brown streak of the darker varieties.
Properties:
Optical properties Pure zinc sulfide is a wide-bandgap semiconductor, with bandgap of about 3.54 electron volts, which makes the pure material transparent in the visible spectrum. Increasing iron content will make the material opaque, while various impurities can give the crystal a variety of colors. In thin section, sphalerite exhibits very high positive relief and appears colorless to pale yellow or brown, with no pleochroism.The refractive index of sphalerite (as measured via sodium light, average wavelength 589.3 nm) ranges from 2.37 when it is pure ZnS to 2.50 when there is 40% iron content. Sphalerite is isotropic under cross-polarized light, however sphalerite can experience birefringence if intergrown with its polymorph wurtzite; the birefringence can increase from 0 (0% wurtzite) up to 0.022 (100% wurtzite).Depending on the impurities, sphalerite will fluoresce under ultraviolet light. Sphalerite can be triboluminescent. Sphalerite has a characteristic triboluminescence of yellow-orange. Typically, specimens cut into end-slabs are ideal for displaying this property.
Varieties:
Gemmy, colorless to pale green sphalerite from Franklin, New Jersey (see Franklin Furnace), are highly fluorescent orange and/or blue under longwave ultraviolet light and are known as cleiophane, an almost pure ZnS variety. Cleiophane contains less than 0.1% of iron in the sphalerite crystal structure. Marmatite or christophite is an opaque black variety of sphalerite and its coloring is due to high quantities of iron, which can reach up to 25%; marmatite is named after Marmato mining district in Colombia and christophite is named for the St. Christoph mine in Breitenbrunn, Saxony. Both marmatite and cleiophane are not recognized by the International Mineralogical Association (IMA). Red, orange or brownish-red sphalerite is termed ruby blende or ruby zinc, whereas dark colored sphalerite is termed black-jack.
Deposit types:
Sphalerite is amongst the most common sulfide minerals, and it is found worldwide and in a variety of deposit types. The reason for the wide distribution of sphalerite is that it appears in many types of deposits; it is found in skarns, hydrothermal deposits, sedimentary beds, volcanogenic massive sulfide deposits (VMS), Mississippi-valley type deposits (MVT), granite and coal.
Deposit types:
Sedimentary exhalitive Approximately 50% of zinc (from sphalerite) and lead comes from Sedimentary exhalative (SEDEX) deposits, which are stratiform Pb-Zn sulfides that form at seafloor vents. The metals precipitate from hydrothermal fluids and are hosted by shales, carbonates and organic-rich siltstones in back-arc basins and failed continental rifts. The main ore minerals in SEDEX deposits are sphalerite, galena, pyrite, pyrrhotite and marcasite, with minor sulfosalts such as tetrahedrite-freibergite and boulangerite; the zinc + lead grade typically ranges between 10 and 20%. Important SEDEX mines are Red Dog in Alaska, Sullivan Mine in British Columbia, Mount Isa and Broken Hill in Australia and Mehdiabad in Iran.
Deposit types:
Mississippi-Valley type Similar to SEDEX, Mississippi-Valley type (MVT) deposits are also a Pb-Zn deposit which contains sphalerite. However, they only account for 15–20% of zinc and lead, are 25% smaller in tonnage than SEDEX deposits and have lower grades of 5–10% Pb + Zn. MVT deposits form from the replacement of carbonate host rocks such as dolostone and limestone by ore minerals; they are located in platforms and foreland thrust belts. Furthermore, they are stratabound, typically Phanerozoic in age and epigenetic (form after the lithification of the carbonate host rocks). The ore minerals are the same as SEDEX deposits: sphalerite, galena, pyrite, pyrrhotite and marcasite, with minor sulfosalts. Mines that contain MVT deposits include Polaris in the Canadian arctic, Mississippi River in the United States, Pine Point in Northwest Territories, and Admiral Bay in Australia.
Deposit types:
Volcanogenic massive sulfide Volcanogenic massive sulfide (VMS) deposits can be Cu-Zn- or Zn-Pb-Cu-rich, and accounts for 25% of Zn in reserves. There are various types of VMS deposits with a range of regional contexts and host rock compositions; a common characteristic is that they are all hosted by submarine volcanic rocks. They form from metals such as copper and zinc being transferred by hydrothermal fluids (modified seawater) which leach them from volcanic rocks in the oceanic crust; the metal-saturated fluid rises through fractures and faults to the surface, where it cools and deposits the metals as a VMS deposit. The most abundant ore minerals are pyrite, chalcopyrite, sphalerite and pyrrhotite. Mines that contain VMS deposits include Kidd Creek in Ontario, Urals in Russia, Troodos in Cyprus and Besshi in Japan.
Deposit types:
Localities The top producers of sphalerite include the United States, Russia, Mexico, Germany, Australia, Canada, China, Ireland, Peru, Kazakhstan and England.Sources of high quality crystals include:
Uses:
Metal ore Sphalerite is an important ore of zinc; around 95% of all primary zinc is extracted from sphalerite ore. However, due to its variable trace element content, sphalerite is also an important source of several other metals such as cadmium, gallium, germanium, and indium which replace zinc. The ore was originally called blende by miners (from German blind or deceiving) because it resembles galena but yields no lead.
Uses:
Brass and bronze The zinc in sphalerite is used to produce brass, an alloy of copper with 3–45% zinc. Major element alloy compositions of brass objects provide evidence that sphalerite was being used to produce brass by the Islamic as far back as the medieval ages between the 7th and 16th century CE. Sphalerite may have also been used during the cementation process of brass in Northern China during the 12th–13th century CE (Jin Dynasty). Similarly to brass, the zinc in sphalerite can also be used to produce certain types of bronze; bronze is dominantly copper which is alloyed with other metals such as tin, zinc, lead, nickel, iron and arsenic.
Uses:
Other Yule Marble – sphalerite is found as intrusions in yule marble, which is used as a building material for the Lincoln Memorial and Tomb of the Unknown.
Galvanized iron – zinc from sphalerite is used as a protective coating to prevent corrosion and rusting; it is used on power transmission towers, nails and automobiles.
Batteries Gemstone
Additional reading:
Dana's Manual of Mineralogy ISBN 0-471-03288-3 Webster, R., Read, P. G. (Ed.) (2000). Gems: Their sources, descriptions and identification (5th ed.), p. 386. Butterworth-Heinemann, Great Britain. ISBN 0-7506-1674-1 | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Landau reflex**
Landau reflex:
Landau reflex or Landau reaction refers to a reflex seen in infants when held horizontally in the air in the prone position. It emerges 3 months after birth and lasts until up to 12 months to 24 months of age. A normal response of infants when held in a horizontal prone position is to maintain a convex arc with the head raised and the legs slightly flexed. It is poor in those with floppy infant syndrome and exaggerated in hypertonic and opisthotonic infants.
Interpretation:
An abnormal Landau reflex may indicate hypotonia or hypertonia and may indicate a motor development issue. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Slurry transport**
Slurry transport:
Slurry transport uses several methods: hydraulic conveying; conventional lean slurry conveying; and high concentration slurry disposal (HCSD). The latter, HCSD, is a relatively modern approach, which is used to transfer high throughputs of fine fly ash over long distances (>10 km or 6.2 mi) using high pressure diaphragm pumps with velocities of around 2 m/s. Ash disposal is simple as the ash solidifies easily and the system does not produce the waste water or leachate problems which can often be associated with ash lagoons.
Examples:
Typical HCSD systems include the Clyde Bergemann solution designed to reduce water usage (up to 90% by weight), reduce ground and surface water pollution, reduce dust emission surrounding landfill site, increase disposal area working capacity and lower energy consumption. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Villin-1**
Villin-1:
Villin-1 is a 92.5 kDa tissue-specific actin-binding protein associated with the actin core bundle of the brush border. Villin-1 is encoded by the VIL1 gene. Villin-1 contains multiple gelsolin-like domains capped by a small (8.5 kDa) "headpiece" at the C-terminus consisting of a fast and independently folding three-helix bundle that is stabilized by hydrophobic interactions. The headpiece domain is a commonly studied protein in molecular dynamics due to its small size and fast folding kinetics and short primary sequence.
Structure:
Villin-1 is made up of seven domains, six homologous domains make up the N-terminal core and the remaining domain makes up the C-terminal cap. Villin contains three phosphatidylinositol 4,5-biphosphate (PIP2) binding sites, one of which is located at the head piece and the other two in the core. The core domain is approximately 150 amino acid residues grouped in six repeats. On this core is an 87 residue, hydrophobic, C-terminal headpiece The headpiece (HP67) is made up of a compact, 70 amino acid folded protein at the C-terminus. This headpiece contains an F-actin binding domain. Residues K38, E39, K65, 70-73:KKEK, G74, L75 and F76 surround a hydrophobic core and are believed to be involved in the binding of F-actin to villin-1. Residues E39 and K70 form a salt bridge buried within the headpiece which serves to connect N and C terminals. This salt bridge may also orient and fix the C-terminal residues involved in F-actin binding as in the absence of this salt bridge no binding occurs. A hydrophobic “cap” is formed by residue W64 side chains, which is completely conserved throughout the villin family. Below this cap is a crown of alternative positive and negative charged localities.
Structure:
Villin can undergo post-translational modifications like tyrosine phosphorylation. Villin-1 has the ability to dimerize and the dimerization site is located at the amino end of the protein.
Expression:
Villin-1 is an actin binding protein expressed mainly in the brush border of the epithelium in vertebrates but sometimes it is ubiquitously expressed in protists and plants. Villin is found localized in the microvilli of the brush border of the epithelium lining of the gut and renal tubules in vertebrates.
Function:
Villin-1 is believed to function in the bundling, nucleation, capping and severing of actin filaments. In vertebrates, villin proteins help to support the microfilaments of the microvilli of the brush border. However, knockout mice appear to show ultra-structurally normal microvilli reminding us that the function of villin is not definitively known; it may play a role in cell plasticity through F-actin severing. The six-repeat villin core is responsible for Ca2+ actin severing while the headpiece is responsible for actin crosslinking and bundling (Ca independent). Villin is postulated to be the controlling protein for Ca2+ induced actin severing in the brush border. Ca2+ inhibits proteolytic cleavage of the domains of the 6 N-terminal core which inhibits actin severing. In normal mice raising Ca2+ levels induces the severing of actin by villin, whereas in villin knockout mice this activity does not occur in response to heightened Ca2+ levels. In the presence of low concentrations of Ca2+ the villin headpiece functions to bundle actin filaments whereas in the presence of high Ca2+ concentrations the N-terminal caps and severs these filaments. The association of PIP2 with villin inhibits the actin capping and severing action and increases actin binding at the headpiece region, possibly through structural changes in the protein. PIP2 increases actin bundling not only by decreasing the severing action of villin but also through dissociating capping proteins, releasing actin monomers from sequestering proteins and stimulating actin nucleation and cross linking.
Villin subdomain:
The C-terminal subdomain of Villin Headpiece VHP67, denoted VHP35, is stabilised in part, by a buried cluster of three phenylalanine residues. Its small size and high helical content are expected to promote rapid folding, and this has been confirmed experimentally. Villin-4 C-terminal construct VHP76 in Arabidopsis thaliana has been shown to exhibit higher affinity for F-actin in increasing concentrations of Ca2+, which further confirms the function of villin.
Villin subdomain:
Structure It has a simple topology consisting of three α-helices that form a well-packed hydrophobic core.
Degradation and regulation:
Currently, it is theorized the regulation of plant villins are caused by degradation via the binding protein auxin, which targets the headpiece domain (VHP). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**KG-84**
KG-84:
The KG-84A and KG-84C are encryption devices developed by the U.S. National Security Agency (NSA) to ensure secure transmission of digital data. The KG-84C is a Dedicated Loop Encryption Device (DLED), and both devices are General-Purpose Telegraph Encryption Equipment (GPTEE). The KG-84A is primarily used for point-to-point encrypted communications via landline, microwave, and satellite systems. The KG-84C is an outgrowth of the U.S. Navy high frequency (HF) communications program and supports these needs. The KG-84A and KG-84C are devices that operate in simplex, half-duplex, or full-duplex modes. The KG-84C contains all of the KG-84 and KG-84A modes, plus a variable update counter, improved HF performance, synchronous out-of-sync detection, asynchronous cipher text, plain text, bypass, and European TELEX protocol. The KG-84 (A/C) is certified to handle data at all levels of security. The KG-84 (A/C) is a Controlled Cryptographic Item (CCI) and is unclassified when unkeyed. Keyed KG-84 equipment assumes the classification level equal to that of the keying material used.
Characteristics:
KG-84 A/C physical characteristics Height 7.8 in (198 mm) Width 7.5 in (191 mm) Depth 15 in (381 mm) Weight 23 lb (10 kg) Data rate KG-84A 256 kbit/s synchronous and 9.6 kbit/s asynchronous KG-84C Up to 64 kbit/s synchronous and 9.6 kbit/s asynchronous Power 24 V DC, 15 W 115 V AC 220 V AC Operating temperature Operating temperature: 0 to 55 °C MTBF 69,000 hours (7.9 years) | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Immunology Letters**
Immunology Letters:
Immunology Letters is a peer-reviewed academic journal of immunology. The journal was established in 1979 and is published by Elsevier on behalf of the European Federation of Immunological Societies on a monthly basis. The current editor is Vaclav Horejsi.
Indexing and abstracting:
The journal is indexed and abstracted in the following bibliographic databases: | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Gliese 876 e**
Gliese 876 e:
Gliese 876 e is an exoplanet orbiting the star Gliese 876 in the constellation of Aquarius. It is in a 1:2:4 Laplace resonance with the planets Gliese 876 c and Gliese 876 b: for each orbit of planet e, planet b completes two orbits and planet c completes four. This configuration is the second known example of a Laplace resonance after Jupiter's moons Io, Europa and Ganymede. Its orbit takes 124 days to complete.
Gliese 876 e:
Gliese 876 e has a mass similar to that of the planet Uranus. Its orbit takes 124 days to complete, or roughly one third of a year. While the orbital period is longer than that of Mercury around the Sun, the lower mass of the host star relative to the Sun means the planet's orbit has a slightly smaller semimajor axis. Unlike Mercury, Gliese 876 e has a nearly circular orbit with an eccentricity of 0.055 ± 0.012.This planet, like b and c, has likely migrated inward. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**4DX**
4DX:
4DX is a 4D film presentation system developed by CJ 4DPlex, a subsidiary of South Korean cinema chain CJ CGV. It allows films to be augmented with various practical effects, including motion-seats, wind, strobe-lights, simulated-snow, and scents. First introduced commercially in 2009, it presents films in both stereoscopic 3-D and monoscopic 2-D formats.CJ has licensed the technology worldwide. As of September 2019, CJ 4DPlex operates 678 4DX theaters in 65 countries through partnerships with more than 80 theaters, including Wanda Cinemas, Cineworld, Regal Cinemas, Kinepolis, Cinépolis, Event Cinemas, Village Cinemas, and Nu Metro. The company recorded an annual growth rate of more than 50 percent from 2013 to 2018.
History:
South Korea The 4DX technology has made its commercial debut at the CGV Sangam theater in Seoul in 2009. Following the success of Avatar, the technology expanded to more theaters in South Korea.
History:
Mexico In June 2011, Mexico-based Cinépolis have invested $25 million and made an agreement with the CJ Group to bring the 4DX technology to its 11 locations in the country, with the first opening in a theater in Mexico City. It marked the technology's debut in the Americas and outside the Asia region, and the technology expanded throughout Mexico since its debut. In 2019, the company announced that they would install the "4DX Screen" theater, a theater with an expanded multi-sided screen with the 4DX theaters, in the country in the summer season of 2020.
History:
Central America In Central America, the technology is available as well in countries like Guatemala through Cinepolis In Costa Rica, the 4DX technology made its commercial debut at Cinépolis in 2014.
South America In 2012, Cinépolis has expanded its 4DX reach to South America, opening its first location at a theater in São Paulo, Brazil. The company later premiered the 4DX theater in Colombia at the El Limonar Shopping Center in Cali in July 2013. Cine Hoyts (now part of Cinépolis) opened the first 4DX theater in Chile in 2013.
History:
United States At CinemaCon in March 2014, CJ 4DPlex announced that it had reached an agreement with AEG and Regal Cinemas to introduce the country's first 4DX auditorium at Regal Cinemas L.A. Live in downtown Los Angeles. In 2018, CJ and Regal's new parent company Cineworld announced that it planned to expand 4DX to at least 79 Regal locations. As of 2020, there is an approximate total of 32 locations throughout the United States, primarily from various Regal locations, one Marcus Theatres location in Gurnee, two Cinépolis locations, and CGV's second U.S. at The Source OC in Buena Park.
History:
Canada Cineplex Entertainment premiered a 4DX auditorium at one of its Toronto locations on 4 November 2016. It opened a second location in Calgary in August 2019. Currently, there are seven 4DX locations in Canada.
History:
Cineplex Cinemas Metropolis, Burnaby, British Columbia Scotiabank Theatre Chinook, Calgary, Alberta Scotiabank Theatre Edmonton, Edmonton, Alberta Cineplex Cinemas Hamilton Mountain, Stoney Creek, Ontario Cineplex Cinemas Winston Churchill & VIP, Oakville, Ontario Scotiabank Theatre Ottawa, Ottawa, Ontario Cineplex Cinemas Yonge-Dundas and VIP, Toronto, Ontario India In India, only few 4DX screens are currently available - PVR Cinemas has ten in Surat, Ahmedabad, Indore, Noida, Hyderabad,Chandigarh. Bangalore,Thiruvananthapuram, Kochi, Gurugram, Pune, Mumbai and New Delhi and Cinépolis also has five screens in Thane, Navi Mumbai, Saket and New Delhi. The first 4DX theatre in Kerala was launched at the Lulu International Shopping Mall in Kochi on 20 December 2021 with the release of Spider-Man: No Way Home. Talking to press after signing the agreement, Ajay Bijli, CMD at PVR said, "In a small time since the launch in Noida, 4DX format has outperformed by far all other formats." Japan Since opening its first theater in partnership with Korona World Cinemas in April 2013, the theater chain has seen an increase in the installation of 4DX theaters. It operates 4DX theaters nationwide in partnership with large theater chains such as Aeon Cinemas and United Cinemas.
History:
Europe (United Kingdom, Ireland, France, Spain, Austria, Denmark, Slovakia and Romania) In 2015 4DX opened in Romania with a lot of hype since it was the first one.In 2017, CJ 4DPLEX partnered with France's Pathé and Denmark's Nordisk Film Kino to open its first 4DX theater in Europe. It quickened its expansion in Europe by signing partnerships with Austrian theater operator Hollywood Megaplex in February 2017 and Cineworld in the United Kingdom and Republic Of Ireland.
History:
China CJ 4DPLEX started integrating 4DX within the Chinese market in cooperation with its parent company CJ CGV in 2006. In 2013, it signed contracts with UME, a local theater operator in China. In 2014, CJ 4DPLEX made partnerships with Woosang More, WoMai, Beijing Jinbo, and Golden Harvest. In December 2014, CJ 4DPLEX formed a partnership with Wanda Cinema, a Chinese theater operator.
History:
South Africa In 2015, CJ 4DPLEX and Nu Metro Cinemas entered a partnership to open 5 4DX theaters in South Africa, making its debut in the African continent. It opened the first 4DX auditorium in December that year with the release of Star Wars: The Force Awakens at the V&A Waterfront theater.
History:
Australia At CinemaCon 2017, 4DX signed a contract with Australian theater operator Village Cinemas to open its first 4DX theater within a year. It opened at the Century City theater in Melbourne, Victoria on 27 October 2017 with the release of Thor: Ragnarok. It was the first time that the company entered Oceania and the Australian continent, and it made the technology available to all six continents.
Box office performance:
In August 2019, 4DX reached 2.7 million moviegoers. The top three performing films for 4DX in August were Fast and Furious Presents: Hobbs & Shaw, The Lion King, and Aladdin. The local films The Bravest and One Piece: Stampede performed well in China and Japan.As of 6 August 2019, the top five movie titles of 4DX global box office hits in the first half of 2019 were: Avengers: Endgame ($34,705K) Aladdin ($24,759K) Aquaman ($21,301K) The Lion King ($16,841K) Captain Marvel ($14,133K)In 2018, the company attracted a cumulative 24 million viewers a year, recording $290 million in box office revenue. In July 2019, the company attracted 3.07 million viewers and $38 million in ticket sales globally.
Variations:
4DX VR The 4DX technology has expanded to virtual-reality, also known as 4DX VR, which utilizes a set of specific 4DX model seats consisting of VR headsets, similar to that of virtual reality amusement rides, and is described to be the "world's first VR theater". First showcased at the AAE 2017 and later IAAPA Attractions Expo 2017, it plays exclusive virtual reality-produced films, short films, as well as games and movie trailers. There are at least six versions of the 4DX VR technology brand: Disk for horizontal rotation, Ride which consists of four-to-eight seats on a 6-axis motion-platform, Racing for presentations focused on the racing genre, Sway and Twist in which seats enable twist and side movements, motion-chair which is a singular 4DX chair consisting of the VR headsets, and Sports for sports-focused presentations with specific bike, snowboard, and kayak designs.
Variations:
4DX Screen The 4DX Screen technology (formerly 4DX with ScreenX) combines the multi-screen projection, known as ScreenX, and the motion-seats in a theater. It was first introduced in 2018 and made its debut in CinemaCon 2018. Both technologies are owned by CJ 4DPLEX.
Awards:
2014: 4DX won the I3DS (International 3-D and Advanced Imaging Society) "Cinema Innovation of the Year" award.
2015: 4DX won the Edison Awards, Silver Prize for Media and Visual Communication Entertainment Category.
2017: 4DX was chosen as one of "The Most Innovative Companies of 2017" for the Live Events Category by the magazine Fast Company.
2018: 4DX and ScreenX won the Edison Awards, Silver Prize for Media and Visual Communication Entertainment Category.
2018: 4DX won the "Innovation Technology of the Year Award" at Big Cine Expo.
2019: 4DX and ScreenX won the iResearch Award, Originative Cinema Technology Category.
2019: 4DX was chosen as one of "The Most Innovative Companies of 2019" for the Live Events Category by Fast Company. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Fungal prion**
Fungal prion:
A fungal prion is a prion that infects hosts which are fungi. Fungal prions are naturally occurring proteins that can switch between multiple, structurally distinct conformations, at least one of which is self-propagating and transmissible to other prions. This transmission of protein state represents an epigenetic phenomenon where information is encoded in the protein structure itself, instead of in nucleic acids. Several prion-forming proteins have been identified in fungi, primarily in the yeast Saccharomyces cerevisiae. These fungal prions are generally considered benign, and in some cases even confer a selectable advantage to the organism.Fungal prions have provided a model for the understanding of disease-forming mammalian prions. Study of fungal prions has led to a characterisation of the sequence features and mechanisms that enable prion domains to switch between functional and amyloid-forming states.
Sequence features:
Prions are formed by portable, transmissible prion domains that are often enriched in asparagine, glutamine, tyrosine and glycine residues. When a reporter protein is fused with a prion domain, it forms a chimeric protein that demonstrates the conformational switching that is characteristic of prions. Meanwhile, removing this prion domain prevents prionogenesis. This suggests that these prion domains are, in fact, portable and are the sole initiator of prionogenesis. This supports the protein-only hypothesis.A recent study of candidate prion domains in S. cerevisiae found several specific sequence features that were common to proteins showing aggregation and self-templating properties. For example, proteins that aggregated had candidate prion domains that were more highly enriched in asparagine, while non-aggregating domains where more highly enriched in glutamine and charged peptides. There was also evidence that the spacing of charged peptides that prevent amyloid formation, such as proline, is important in prionogenesis. This discovery of sequence specificity was a departure from previous work that had suggested that the only determining factor in prionogenesis was the overall distribution of peptides.
HET-s prion of Podospora anserina:
Podospora anserina is a filamentous fungus. Genetically compatible colonies of this fungus can merge and share cellular contents such as nutrients and cytoplasm. A natural system of protective "incompatibility" proteins exists to prevent promiscuous sharing between unrelated colonies. One such protein, called HET-s, adopts a prion-like form in order to function properly. The prion form of HET-s spreads rapidly throughout the cellular network of a colony and can convert the non-prion form of the protein to a prion state after compatible colonies have merged. However, when an incompatible colony tries to merge with a prion-containing colony, the prion causes the "invader" cells to die, ensuring that only related colonies obtain the benefit of sharing resources.
Prions of yeast:
[PSI+] and [URE3] In 1965, Brian Cox, a geneticist working with the yeast Saccharomyces cerevisiae, described a genetic trait (termed [PSI+]) with an unusual pattern of inheritance. The initial discovery of [PSI+] was made in a strain auxotrophic for adenine due to a nonsense mutation. Despite many years of effort, Cox could not identify a conventional mutation that was responsible for the [PSI+] trait. In 1994, yeast geneticist Reed Wickner correctly hypothesized that [PSI+] as well as another mysterious heritable trait, [URE3], resulted from prion forms of the normal cellular proteins, Sup35p and Ure2p, respectively. The names of yeast prions are frequently placed within brackets to indicate that they are non-mendelian in their passage to progeny cells, much like plasmid and mitochondrial DNA.Further investigation found that [PSI+] is the result of a self-propagating misfolded form of Sup35p (a 201 amino acid long protein), which is an important factor for translation termination during protein synthesis. In [PSI+] yeast cells the Sup35 protein forms filamentous aggregates known as amyloid. The amyloid conformation is self-propagating and represents the prion state. Amazingly distinct prion states exist for the Sup35 protein with distinct properties and these distinctions are self-propagating. Other prions also can form distinct different variants (or strains). It is believed that suppression of nonsense mutations in [PSI+] cells is due to a reduced amount of functional Sup35 because much of the protein is in the amyloid state. The Sup35 protein assembles into amyloid via an amino-terminal prion domain. The structure is based on the stacking of the prion domains in an in-register and parallel beta sheet conformation.An important finding by Chernoff, in a collaboration between the Liebman and Lindquist laboratories, was that a protein chaperone was required for [PSI+] to be maintained. Because the only function of chaperones is to help proteins fold properly, this finding strongly supported Wickner's hypothesis that [PSI+] was a heritable protein state (i.e. a prion). Likewise, this finding also provided evidence for the general hypothesis that prions, including the originally proposed mammalian PrP prion, are heritable forms of protein. Because of the action of chaperones, especially Hsp104, proteins that code for [PSI+] and [URE3] can convert from non-prion to prion forms. For this reason, yeast prions are good models for studying factors like chaperones that affect protein aggregation. Also, the IPOD is the sub-cellular site to which amyloidogenic proteins are sequestered in yeast, and where prions like [PSI+] may undergo maturation. Thus, prions also serve as substrates to understand the intracellular processing of protein aggregates such as amyloid.Laboratories commonly identify [PSI+] by growth of a strain auxotrophic for adenine on media lacking adenine, similar to that used by Cox et al. These strains cannot synthesize adenine due to a nonsense mutation in one of the enzymes involved in the biosynthetic pathway. When the strain is grown on yeast-extract/dextrose/peptone media (YPD), the blocked pathway results in buildup of a red-colored intermediate compound, which is exported from the cell due to its toxicity. Hence, color is an alternative method of identifying [PSI+] -- [PSI+] strains are white or pinkish in color, and [psi-] strains are red. A third method of identifying [PSI+] is by the presence of Sup35 in the pelleted fraction of cellular lysate.
Prions of yeast:
When exposed to certain adverse conditions, in some genetic backgrounds [PSI+] cells actually fare better than their prion-free siblings; this finding suggests that the ability to adopt a [PSI+] prion form may result from positive evolutionary selection. It has been speculated that the ability to convert between prion-infected and prion-free forms acts as an evolutionary capacitor to enable yeast to quickly and reversibly adapt in variable environments. Nevertheless, Reed Wickner maintains that [URE3] and [PSI+] are diseases, although this claim has been challenged using theoretical population genetic models.
Prions of yeast:
[PIN+] / [RNQ+] The term [PIN+] was coined by Liebman and colleagues from Psi-INducibility, to describe a genetic requirement for the formation of the [PSI+] prion. They showed that [PIN+] was required for the induction of most variants of the [PSI+] prion. Later they identified [PIN+] as the prion form of the RNQ1 protein The more precise name [RNQ+] is now sometimes used because other factors or prions can also have a Psi-inducing phenotype.A non-prion function of Rnq1 has not been definitively characterized. Though reasons for this are poorly understood, it is suggested that [PIN+] aggregates may act as "seeds" for the polymerization of [PSI+] and other prions. The basis of the [PIN+] prion is an amyloid form of Rnq1 arranged in in-register parallel beta sheets, like the amyloid form of Sup35. Due to similar amyloid structures, the [PIN+] prion may facilitate the formation of [PSI+] through a templating mechanism.Two modified versions of Sup35 have been created that can induce PSI+ in the absence of [PIN+] when overexpressed. One version was created by digestion of the gene with the restriction enzyme Bal2, which results in a protein consisting of only the M and N portions of Sup35. The other is a fusion of Sup35NM with HPR, a human membrane receptor protein.
Epigenetics:
Prions act as an alternative form of non-Mendelian, phenotypic inheritance due to their self-templating ability. This makes prions a metastable, dominant mechanism for inheritance that relies solely on the conformation of the protein. Many proteins containing prion domains play a role in gene expression or RNA binding, which is how an alternative conformation can give rise to phenotypic variation. For example, the [psi-] state of Sup35 in yeast is a translation termination factor. When Sup35 undergoes a conformational change to the [PSI+] prion state, it forms amyloid fibrils and is sequestered, leading to more frequent stop codon read-through and the development of novel phenotypes. With over 20 prion-like domains identified in yeast, this gives rise to the opportunity for a significant amount of variation from a single proteome. It has been posited that this increased variation gives a selectable advantage to a population of genetically homogeneous yeast.
List of characterized prions:
[*The original paper that proposed Mca1 is a prion was retracted ] | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**N conjecture**
N conjecture:
In number theory the n conjecture is a conjecture stated by Browkin & Brzeziński (1994) as a generalization of the abc conjecture to more than three integers.
Formulations:
Given n≥3 , let a1,a2,...,an∈Z satisfy three conditions: (i) gcd (a1,a2,...,an)=1 (ii) a1+a2+...+an=0 (iii) no proper subsum of a1,a2,...,an equals 0 First formulation The n conjecture states that for every ε>0 , there is a constant C , depending on n and ε , such that: max rad (|a1|⋅|a2|⋅...⋅|an|)2n−5+ε where rad (m) denotes the radical of the integer m , defined as the product of the distinct prime factors of m Second formulation Define the quality of a1,a2,...,an as log max log rad (|a1|⋅|a2|⋅...⋅|an|)) The n conjecture states that lim sup q(a1,a2,...,an)=2n−5
Stronger form:
Vojta (1998) proposed a stronger variant of the n conjecture, where setwise coprimeness of a1,a2,...,an is replaced by pairwise coprimeness of a1,a2,...,an There are two different formulations of this strong n conjecture.
Stronger form:
Given n≥3 , let a1,a2,...,an∈Z satisfy three conditions: (i) a1,a2,...,an are pairwise coprime (ii) a1+a2+...+an=0 (iii) no proper subsum of a1,a2,...,an equals 0 First formulation The strong n conjecture states that for every ε>0 , there is a constant C , depending on n and ε , such that: max rad (|a1|⋅|a2|⋅...⋅|an|)1+ε Second formulation Define the quality of a1,a2,...,an as log max log rad (|a1|⋅|a2|⋅...⋅|an|)) The strong n conjecture states that lim sup q(a1,a2,...,an)=1 | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Nodal homolog**
Nodal homolog:
Nodal homolog is a secretory protein that in humans is encoded by the NODAL gene which is located on chromosome 10q22.1. It belongs to the transforming growth factor beta superfamily (TGF-β superfamily). Like many other members of this superfamily it is involved in cell differentiation in early embryogenesis, playing a key role in signal transfer from the primitive node, in the anterior primitive streak, to lateral plate mesoderm (LPM).Nodal signaling is important very early in development for mesoderm and endoderm formation and subsequent organization of left-right axial structures. In addition, Nodal seems to have important functions in neural patterning, stem cell maintenance and many other developmental processes, including left/right handedness.
Signaling:
Nodal can bind type I and type II serine/threonine kinase receptors, with Cripto-1 acting as its co-receptor. Signaling through SMAD 2/3 and subsequent translocation of SMAD 4 to the nucleus promotes the expression of genes involved in proliferation and differentiation. Nodal also further activates its own expression via a positive feedback loop. It is tightly regulated by inhibitors Lefty A, Lefty B, Cerberus, and Tomoregulin-1, which can interfere with Nodal receptor binding.
Species specific Nodal ligands:
Nodal is a widely distributed cytokine. The presence of Nodal is not limited to vertebrates, it is also known to be conserved in other deuterostomes (cephalochordates, tunicates and echinoderms) and protostomes such as snails, but neither the nematode C. elegans (another protosome) nor the fruit fly Drosophila (an arthropod) have a copy of nodal. Although mouse and human only have one nodal gene, the zebrafish contain three nodal paralogs: squint , cyclops and southpaw, and the frog five (xnr1,2,3,5 and 6). Even though the zebrafish Nodal homologs are very similar, they have specialized to perform different roles; for instance, Squint and Cyclops are important for mesoendoderm formation, whereas the Southpaw has a major role in asymmetric heart morphogenesis and visceral left-right asymmetry. Another example of protein speciation is the case of the frog where Xnr1 and Xnr2 regulate movements in gastrulation in contrast to Xnr5 and Xnr6 that are involved in mesoderm induction. In mouse, Nodal has been implicated in left-right asymmetry, neural pattering and mesoderm induction (see nodal signaling).
Functions:
Nodal signaling regulates mesoderm formation in a species-specific manner. Thus, in Xenopus, Xnr controls dorso-ventral mesoderm formation along the marginal zone. In zebrafish, Squint and Cyclops are responsible for animal-vegetal mesoderm formation. In chicken and mouse, Vg1 and Nodal respectively promote primitive streak formation in the epiblast. In chick development, Nodal is expressed in Koller's sickle. Studies have shown that a nodal knockout in mouse causes the absence of the primitive streak and failure in the formation of mesoderm, leading to developmental arrest just after gastrulation.Compared to mesoderm specification, endoderm specification requires a higher expression of Nodal. Here, Nodal stimulates mixer homeoproteins, which can interact with SMADs in order to up-regulate endoderm specific genes and repress mesoderm specific genes.Left-right asymmetry (LR asymmetry) of visceral organs in vertebrates is also established through nodal signaling. Whereas Nodal is initially symmetrically expressed in the embryo, after gastrulation, Nodal becomes asymmetrically restricted to the left side of the organism. It is highly conserved among deuterostomes. An ortholog of Nodal was found in snails and was shown to be involved in left-right asymmetry as well in 2008.In order to enable anterior neural tissue development, Nodal signaling needs to be repressed after inducing mesendoderm and LR asymmetry.Recent research on mouse and human embryonic stem cells (hESCs) indicates that Nodal seems to be involved in the maintenance of stem cell self-renewal and pluripotent potentials. Thus, overexpression of Nodal in hESCs lead to the repression of cell differentiation. On the contrary, inhibition of Nodal and Activin signaling enabled the differentiation of hESCs. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Periodontal disease**
Periodontal disease:
Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth. In its early stage, called gingivitis, the gums become swollen and red and may bleed. It is considered the main cause of tooth loss for adults worldwide. In its more serious form, called periodontitis, the gums can pull away from the tooth, bone can be lost, and the teeth may loosen or fall out. Bad breath may also occur.Periodontal disease is generally due to bacteria in the mouth infecting the tissue around the teeth. Factors that increase the risk of disease include smoking, diabetes, HIV/AIDS, family history, and certain medications. Diagnosis is by inspecting the gum tissue around the teeth both visually and with a probe and X-rays looking for bone loss around the teeth.Treatment involves good oral hygiene and regular professional teeth cleaning. Recommended oral hygiene include daily brushing and flossing. In certain cases antibiotics or dental surgery may be recommended. Clinical investigations demonstrate that quitting smoking and making dietary changes enhance periodontal health. Globally 538 million people were estimated to be affected in 2015 and has been known to affect 10–15% of the population generally. In the United States nearly half of those over the age of 30 are affected to some degree, and about 70% of those over 65 have the condition. Males are affected more often than females.
Signs and symptoms:
In the early stages, periodontitis has very few symptoms, and in many individuals the disease has progressed significantly before they seek treatment.
Signs and symptoms:
Symptoms may include: Redness or bleeding of gums while brushing teeth, using dental floss or biting into hard food (e.g., apples) (though this may also occur in gingivitis, where there is no attachment loss gum disease) Gum swelling that recurs Spitting out blood after brushing teeth Halitosis, or bad breath, and a persistent metallic taste in the mouth Gingival recession, resulting in apparent lengthening of teeth (this may also be caused by heavy-handed brushing or with a stiff toothbrush) Deep pockets between the teeth and the gums (pockets are sites where the attachment has been gradually destroyed by collagen-destroying enzymes, known as collagenases) Loose teeth, in the later stages (though this may occur for other reasons, as well)Gingival inflammation and bone destruction are largely painless. Hence, people may wrongly assume painless bleeding after teeth cleaning is insignificant, although this may be a symptom of progressing periodontitis in that person.
Signs and symptoms:
Associated conditions Periodontitis has been linked to increased inflammation in the body, such as indicated by raised levels of C-reactive protein and interleukin-6. It is associated with an increased risk of stroke, myocardial infarction, atherosclerosis and hypertension. It also linked in those over 60 years of age to impairments in delayed memory and calculation abilities. Individuals with impaired fasting glucose and diabetes mellitus have higher degrees of periodontal inflammation, and often have difficulties with balancing their blood glucose level owing to the constant systemic inflammatory state, caused by the periodontal inflammation. Although no causal association was proven, there is an association between chronic periodontitis and erectile dysfunction, inflammatory bowel disease, heart disease, and pancreatic cancer.
Signs and symptoms:
Diabetes and periodontal disease A positive correlation between raised levels of glucose within the blood and the onset or progression of periodontal disease has been shown in the current literature.
Signs and symptoms:
Data has also shown that there is a significant increase in the incidence or progression of periodontitis in patients with uncontrolled diabetes compared to those who do not have diabetes or have well-controlled diabetes. In uncontrolled diabetes, the formation of reactive oxygen species can damage cells such as those in the connective tissue of the periodontal ligament, resulting in cell necrosis or apoptosis. Furthermore, individuals with uncontrolled diabetes mellitus who have frequent exposure to periodontal pathogens have a greater immune response to these bacteria. This can subsequently cause and/or accelerate periodontal tissue destruction leading to periodontal disease.Oral cancer and periodontal disease Current literature suggests a link between periodontal disease and oral cancer. Studies have confirmed an increase in systemic inflammation markers such as C-Reactive Protein and Interleukin-6 to be found in patients with advanced periodontal disease. The link between systemic inflammation and oral cancer has also been well established.
Signs and symptoms:
Both periodontal disease and cancer risk are associated with genetic susceptibility and it is possible that there is a positive association by a shared genetic susceptibility in the two diseases.
Signs and symptoms:
Due to the low incidence rate of oral cancer, studies have not been able to conduct quality studies to prove the association between the two, however future larger studies may aid in the identification of individuals at a higher risk.Systemic implications Periodontal disease (PD) can be described as an inflammatory condition affecting the supporting structures of the teeth. Studies have shown that PD is associated with higher levels of systemic inflammatory markers such as Interleukin-6 (IL-6), C-Reactive Protein (CRP) and Tumor Necrosis Factor (TNF). To compare, elevated levels of these inflammatory markers are also associated with cardiovascular disease and cerebrovascular events such as ischemic strokes.The presence of a wide spectrum inflammatory oral diseases can increase the risk of an episode of stroke in an acute or chronic phase. Inflammatory markers, CRP, IL-6 are known risk factors of stroke. Both inflammatory markers are also biomarkers of PD and found to be an increased level after daily activities, such as mastication or toothbrushing, are performed. Bacteria from the periodontal pockets will enter the bloodstream during these activities and the current literature suggests that this may be a possible triggering of the aggravation of the stroke process.Other mechanisms have been suggested, PD is a known chronic infection. It can aid in the promotion of atherosclerosis by the deposition of cholesterol, cholesterol esters and calcium within the subendothelial layer of vessel walls. Atherosclerotic plaque that is unstable may rupture and release debris and thrombi that may travel to different parts of the circulatory system causing embolization and therefore, an ischemic stroke. Therefore, PD has been suggested as an independent risk factor for stroke.
Signs and symptoms:
A variety of cardiovascular diseases can also be associated with periodontal disease. Patients with higher levels of inflammatory markers such as TNF, IL-1, IL-6 and IL-8 can lead to progression of atherosclerosis and the development and perpetuation of atrial fibrillation, as it is associated with platelet and coagulation cascade activations, leading to thrombosis and thrombotic complications.
Signs and symptoms:
Experimental animal studies have shown a link between periodontal disease, oxidative stress and cardiac stress. Oxidative stress favours the development and progression of heart failure as it causes cellular dysfunction, oxidation of proteins and lipids, and damage to the deoxyribonucleic acid (DNA), stimulating fibroblast proliferation and metalloproteinases activation favouring cardiac remodelling.During SARS Covid 19 pandemic, Periodontitis was significantly associated with a higher risk of complications from COVID‐19, including ICU admission, need for assisted ventilation and death and increased blood levels of markers such as D‐dimer, WBC and CRP which are linked with worse disease outcome.
Clinical significance:
Inadequate nutrition and periodontal disease Periodontal disease is multifactorial, and nutrition can significantly affect its prognosis. Studies have shown that a healthy and well-balanced diet is crucial to maintaining periodontal health. Nutritional deficiencies can lead to oral manifestations such as those in scurvy and rickets disease. Different vitamins will play a different role in periodontal health: Vitamin C: Deficiencies may lead to gingival inflammation and bleeding, subsequently advancing periodontal disease Vitamin D: Deficiencies may lead to delayed post-surgical healing Vitamin E: Deficiencies may lead to impaired gingival wound healing Vitamin K: Deficiencies may lead to gingival bleedingNutritional supplements of vitamins have also been shown to positively affect healing after periodontal surgery and many of these vitamins can be found in a variety of food that we eat within a regular healthy diet. Therefore, vitamin intakes (particularly vitamin C) and dietary supplements not only play a role in improving periodontal health, but also influence the rate of bone formation and periodontal regeneration. However, studies supporting the correlation between nutrition and periodontal health are limited, and more long-term research is required to confirm this.
Causes:
Periodontitis is an inflammation of the periodontium, i.e., the tissues that support the teeth. The periodontium consists of four tissues: gingiva, or gum tissue, cementum, or outer layer of the roots of teeth, alveolar bone, or the bony sockets into which the teeth are anchored, and periodontal ligaments (PDLs), which are the connective tissue fibers that run between the cementum and the alveolar bone.The primary cause of gingivitis is poor or ineffective oral hygiene, which leads to the accumulation of a mycotic and bacterial matrix at the gum line, called dental plaque. Other contributors are poor nutrition and underlying medical issues such as diabetes. Diabetics must be meticulous with their homecare to control periodontal disease. New finger prick tests have been approved by the Food and Drug Administration in the US, and are being used in dental offices to identify and screen people for possible contributory causes of gum disease, such as diabetes.
Causes:
In some people, gingivitis progresses to periodontitis – with the destruction of the gingival fibers, the gum tissues separate from the tooth and deepened sulcus, called a periodontal pocket. Subgingival microorganisms (those that exist under the gum line) colonize the periodontal pockets and cause further inflammation in the gum tissues and progressive bone loss. Examples of secondary causes are those things that, by definition, cause microbic plaque accumulation, such as restoration overhangs and root proximity.
Causes:
Smoking is another factor that increases the occurrence of periodontitis, directly or indirectly, and may interfere with or adversely affect its treatment. It is arguably the most important environmental risk factor for periodontitis. Research has shown that smokers have more bone loss, attachment loss and tooth loss compared to non-smokers. This is likely due to several effects of smoking on the immune response including decreased wound healing, suppression of antibody production, and the reduction of phagocytosis by neutrophilsEhlers–Danlos syndrome and Papillon–Lefèvre syndrome (also known as palmoplantar keratoderma) are also risk factors for periodontitis.
Causes:
If left undisturbed, microbial plaque calcifies to form calculus, which is commonly called tartar. Calculus above and below the gum line must be removed completely by the dental hygienist or dentist to treat gingivitis and periodontitis. Although the primary cause of both gingivitis and periodontitis is the microbial plaque that adheres to the tooth surfaces, there are many other modifying factors. A very strong risk factor is one's genetic susceptibility. Several conditions and diseases, including Down syndrome, diabetes, and other diseases that affect one's resistance to infection, also increase susceptibility to periodontitis.
Causes:
Periodontitis may be associated with higher stress. Periodontitis occurs more often in people from the lower end of the socioeconomic scale than people from the upper end of the socioeconomic scale.Genetics appear to play a role in determining the risk for periodontitis. It is believed genetics could explain why some people with good plaque control have advanced periodontitis, whilst some others with poor oral hygiene are free from the disease. Genetic factors which could modify the risk of a person developing periodontitis include: Defects of phagocytosis: person may have hypo-responsive phagocytes.
Causes:
Hyper-production of interleukins, prostaglandins and cytokines, resulting in an exaggerated immune response.
Causes:
Interleukin 1 (IL-1) gene polymorphism: people with this polymorphism produce more IL-1, and subsequently are more at risk of developing chronic periodontitis.Diabetes appears to exacerbate the onset, progression, and severity of periodontitis. Although the majority of research has focused on type 2 diabetes, type 1 diabetes appears to have an identical effect on the risk for periodontitis. The extent of the increased risk of periodontitis is dependent on the level of glycaemic control. Therefore, in well managed diabetes there seems to be a small effect of diabetes on the risk for periodontitis. However, the risk increases exponentially as glycaemic control worsens. Overall, the increased risk of periodontitis in diabetics is estimated to be between two and three times higher. So far, the mechanisms underlying the link are not fully understood, but it is known to involve aspects of inflammation, immune functioning, neutrophil activity, and cytokine biology.
Mechanism:
As dental plaque or biofilm accumulates on the teeth near and below the gums there is some dysbiosis of the normal oral microbiome. As of 2017 it was not certain what species were most responsible for causing harm, but gram-negative anaerobic bacteria, spirochetes, and viruses have been suggested; in individual people it is sometimes clear that one or more species is driving the disease. Research in 2004 indicated three gram negative anaerobic species: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus and Eikenella corrodens.Plaque may be soft and uncalcified, hard and calcified, or both; for plaques that are on teeth the calcium comes from saliva; for plaques below the gumline, it comes from blood via oozing of inflamed gums.The damage to teeth and gums comes from the immune system as it attempts to destroy the microbes that are disrupting the normal symbiosis between the oral tissues and the oral microbe community. As in other tissues, Langerhans cells in the epithelium take up antigens from the microbes, and present them to the immune system, leading to movement of white blood cells into the affected tissues. This process in turn activates osteoclasts which begin to destroy bone, and it activates matrix metalloproteinases that destroy ligaments. So, in summary, it is bacteria which initiates the disease, but key destructive events are brought about by the exaggerated response from the host's immune system.
Classification:
There were several attempts to introduce an agreed-upon classification system for periodontal diseases: in 1989, 1993, 1999, and 2017.
Classification:
1999 classification The 1999 classification system for periodontal diseases and conditions listed seven major categories of periodontal diseases, of which 2–6 are termed destructive periodontal disease, because the damage is essentially irreversible. The seven categories are as follows: Gingivitis Chronic periodontitis Aggressive periodontitis Periodontitis as a manifestation of systemic disease Necrotizing ulcerative gingivitis/periodontitis Abscesses of the periodontium Combined periodontic-endodontic lesionsMoreover, terminology expressing both the extent and severity of periodontal diseases are appended to the terms above to denote the specific diagnosis of a particular person or group of people.
Classification:
Severity The "severity" of disease refers to the amount of periodontal ligament fibers that have been lost, termed "clinical attachment loss". According to the 1999 classification, the severity of chronic periodontitis is graded as follows: Slight: 1–2 mm (0.039–0.079 in) of attachment loss Moderate: 3–4 mm (0.12–0.16 in) of attachment loss Severe: ≥ 5 mm (0.20 in) of attachment loss Extent The "extent" of disease refers to the proportion of the dentition affected by the disease in terms of percentage of sites. Sites are defined as the positions at which probing measurements are taken around each tooth and, generally, six probing sites around each tooth are recorded, as follows: Mesiobuccal Mid-buccal Distobuccal Mesiolingual Mid-lingual DistolingualIf up to 30% of sites in the mouth are affected, the manifestation is classified as "localized"; for more than 30%, the term "generalized" is used.
Classification:
2017 classification The 2017 classification of periodontal diseases is as follows:Periodontal health, gingival disease and conditions Periodontal health and gingival health Clinical gingival health on an intact periodontium Clinical gingival health on an intact periodontium Stable periodontitis Non periodontitis person Gingivitis - Dental biofilm induced Associated with the dental biofilm alone Mediated by systemic and local risk factors Drug induced gingival enlargement.
Classification:
Gingival diseases - Non dental biofilm induced Genetic/developmental disorders Specific infections Inflammatory and immune conditions Reactive processes Neoplasms Endocrine, nutritional and metabolic Traumatic lesions Gingival pigmentation.Periodontitis Necrotizing periodontal diseases Necrotizing Gingivitis Necrotizing periodontitis Necrotizing stomatitis Periodontitis as a manifestation of systemic disease PeriodontitisOther conditions affecting the periodontium (Periodontal Manifestations of Systemic Diseases and Developmental and Acquired Conditions) Systemic disease of conditions affecting the periodontal support tissues Other Periodontal Conditions Periodontal abscesses Endodontic- periodontal lesions Mucogingival deformities and conditions Gingival Phenotype Gingival/Soft Tissue Recession Lack of Gingiva Decreased Vestibular Depth Aberrant Frenum/muscle position Gingival Excess Abnormal Color Condition of the exposed root surface Traumatic occlusal forces Primary Occlusal Trauma Secondary Occlusal Trauma Tooth and prosthesis related factors Localized tooth-related factors Localized dental prostheses-related factorsPeri-implant diseases and conditions Peri-implant health Peri-implant mucositis Peri-implantitis Peri-implant soft and hard tissue deficiencies Staging The goals of staging periodontitis is to classify the severity of damage and assess specific factors that may affect management.According to the 2017 classification, periodontitis is divided into four stages; after considering a few factors such as: Amount and percentage bone loss radiographically Clinical attachment loss, probing depth Presence of furcation Vertical bony defects History of tooth loss related to periodontitis Tooth hypermobility due to secondary occlusal trauma Grading According to the 2017 classification, the grading system for periodontitis consists of three grades: Grade A: Slow progression of disease; no evidence of bone loss over last five years Grade B: Moderate progression; < 2mm of bone loss over last five years Grade C: Rapid progression or future progression at high risk; ≥ 2mm bone loss over five yearsRisk factors affecting which grade a person is classified into include: Smoking Diabetes
Prevention:
Daily oral hygiene measures to prevent periodontal disease include: Brushing properly on a regular basis (at least twice daily), with the person attempting to direct the toothbrush bristles underneath the gumline, helps disrupt the bacterial-mycotic growth and formation of subgingival plaque.
Flossing daily and using interdental brushes (if the space between teeth is large enough), as well as cleaning behind the last tooth, the third molar, in each quarter.
Using an antiseptic mouthwash: Chlorhexidine gluconate-based mouthwash in combination with careful oral hygiene may cure gingivitis, although they cannot reverse any attachment loss due to periodontitis.
Prevention:
Regular dental check-ups and professional teeth cleaning as required: Dental check-ups serve to monitor the person's oral hygiene methods and levels of attachment around teeth, identify any early signs of periodontitis, and monitor response to treatment.Typically, dental hygienists (or dentists) use special instruments to clean (debride) teeth below the gumline and disrupt any plaque growing below the gumline. This is a standard treatment to prevent any further progress of established periodontitis. Studies show that after such a professional cleaning (periodontal debridement), microbial plaque tends to grow back to precleaning levels after about three to four months. Nonetheless, the continued stabilization of a person's periodontal state depends largely, if not primarily, on the person's oral hygiene at home, as well as on the go. Without daily oral hygiene, periodontal disease will not be overcome, especially if the person has a history of extensive periodontal disease.
Management:
The cornerstone of successful periodontal treatment starts with establishing excellent oral hygiene. This includes twice-daily brushing with daily flossing. Also, the use of an interdental brush is helpful if space between the teeth allows. For smaller spaces, products such as narrow picks with soft rubber bristles provide excellent manual cleaning. Persons with dexterity problems, such as with arthritis, may find oral hygiene to be difficult and may require more frequent professional care and/or the use of a powered toothbrush. Persons with periodontitis must realize it is a chronic inflammatory disease and a lifelong regimen of excellent hygiene and professional maintenance care with a dentist/hygienist or periodontist is required to maintain affected teeth.
Management:
Initial therapy Removal of microbial plaque and calculus is necessary to establish periodontal health. The first step in the treatment of periodontitis involves nonsurgical cleaning below the gum line with a procedure called "root surface instrumentation" or "RSI", this causes a mechanical disturbance to the bacterial biofilm below the gumline. This procedure involves the use of specialized curettes to mechanically remove plaque and calculus from below the gumline, and may require multiple visits and local anesthesia to adequately complete. In addition to initial RSI, it may also be necessary to adjust the occlusion (bite) to prevent excessive force on teeth that have reduced bone support. Also, it may be necessary to complete any other dental needs, such as replacement of rough, plaque-retentive restorations, closure of open contacts between teeth, and any other requirements diagnosed at the initial evaluation. It is important to note that RSI is different to scaling and root planing: RSI only removes the calculus, while scaling and root planing removes the calculus as well as underlying softened dentine, which leaves behind a smooth and glassy surface, which is not a requisite for periodontal healing. Therefore, RSI is now advocated over root planing.
Management:
Reevaluation Nonsurgical scaling and root planing are usually successful if the periodontal pockets are shallower than 4–5 mm (0.16–0.20 in). The dentist or hygienist must perform a re-evaluation four to six weeks after the initial scaling and root planing, to determine if the person's oral hygiene has improved and inflammation has regressed. Probing should be avoided then, and an analysis by gingival index should determine the presence or absence of inflammation. The monthly reevaluation of periodontal therapy should involve periodontal charting as a better indication of the success of treatment, and to see if other courses of treatment can be identified. Pocket depths of greater than 5–6 mm (0.20–0.24 in) which remain after initial therapy, with bleeding upon probing, indicate continued active disease and will very likely lead to further bone loss over time. This is especially true in molar tooth sites where furcations (areas between the roots) have been exposed.
Management:
Surgery If nonsurgical therapy is found to have been unsuccessful in managing signs of disease activity, periodontal surgery may be needed to stop progressive bone loss and regenerate lost bone where possible. Many surgical approaches are used in the treatment of advanced periodontitis, including open flap debridement and osseous surgery, as well as guided tissue regeneration and bone grafting. The goal of periodontal surgery is access for definitive calculus removal and surgical management of bony irregularities which have resulted from the disease process to reduce pockets as much as possible. Long-term studies have shown, in moderate to advanced periodontitis, surgically treated cases often have less further breakdown over time and, when coupled with a regular post-treatment maintenance regimen, are successful in nearly halting tooth loss in nearly 85% of diagnosed people.
Management:
Local drug delivery Local drug deliveries in periodontology has gained acceptance and popularity compared to systemic drugs due to decreased risk in development of resistant flora and other side effects. A meta analysis of local tetracycline found improvement. Local application of statin may be useful.
Management:
Systemic drug delivery Systemic drug delivery in conjunction with non-surgical therapy may be used as a means to reduce the percentage of the bacterial plaque load in the mouth. Many different antibiotics and also combinations of them have been tested; however, there is yet very low-certainty evidence of any significant difference in the short and long term compared to non-surgical therapy alone. It may be beneficial to limit the use of systemic drugs, since bacteria can develop antimicrobial resistance and some specific antibiotics might induce temporary mild adverse effects, such as nausea, diarrhoea and gastrointestinal disturbances.
Management:
Adjunctive systemic antimicrobial treatment There is currently low-quality evidence suggesting if adjunctive systemic antimicrobials are beneficial for the non-surgical treatment of periodontitis. It is not sure whether some antibiotics are better than others when used alongside scaling and root planing).
Management:
Maintenance Once successful periodontal treatment has been completed, with or without surgery, an ongoing regimen of "periodontal maintenance" is required. This involves regular checkups and detailed cleanings every three months to prevent repopulation of periodontitis-causing microorganisms, and to closely monitor affected teeth so early treatment can be rendered if the disease recurs. Usually, periodontal disease exists due to poor plaque control resulting from inappropriate brushing. Therefore, if the brushing techniques are not modified, a periodontal recurrence is probable.
Management:
Other Most alternative "at-home" gum disease treatments involve injecting antimicrobial solutions, such as hydrogen peroxide, into periodontal pockets via slender applicators or oral irrigators. This process disrupts anaerobic micro-organism colonies and is effective at reducing infections and inflammation when used daily. A number of other products, functionally equivalent to hydrogen peroxide, are commercially available, but at substantially higher cost. However, such treatments do not address calculus formations, and so are short-lived, as anaerobic microbial colonies quickly regenerate in and around calculus.
Management:
Doxycycline may be given alongside the primary therapy of scaling (see § initial therapy). Doxycycline has been shown to improve indicators of disease progression (namely probing depth and attachment level). Its mechanism of action involves inhibition of matrix metalloproteinases (such as collagenase), which degrade the teeth's supporting tissues (periodontium) under inflammatory conditions. To avoid killing beneficial oral microbes, only small doses of doxycycline (20 mg) are used.Phage therapy may be a new therapeutic alternative.
Prognosis:
Dentists and dental hygienists measure periodontal disease using a device called a periodontal probe. This thin "measuring stick" is gently placed into the space between the gums and the teeth, and slipped below the gumline. If the probe can slip more than 3 mm (0.12 in) below the gumline, the person is said to have a gingival pocket if no migration of the epithelial attachment has occurred or a periodontal pocket if apical migration has occurred. This is somewhat of a misnomer, as any depth is, in essence, a pocket, which in turn is defined by its depth, i.e., a 2-mm pocket or a 6-mm pocket. However, pockets are generally accepted as self-cleansable (at home, by the person, with a toothbrush) if they are 3 mm or less in depth. This is important because if a pocket is deeper than 3 mm around the tooth, at-home care will not be sufficient to cleanse the pocket, and professional care should be sought. When the pocket depths reach 6 to 7 mm (0.24 to 0.28 in) in depth, the hand instruments and ultrasonic scalers used by the dental professionals may not reach deeply enough into the pocket to clean out the microbial plaque that causes gingival inflammation. In such a situation, the bone or the gums around that tooth should be surgically altered or it will always have inflammation which will likely result in more bone loss around that tooth. An additional way to stop the inflammation would be for the person to receive subgingival antibiotics (such as minocycline) or undergo some form of gingival surgery to access the depths of the pockets and perhaps even change the pocket depths so they become 3 mm or less in depth and can once again be properly cleaned by the person at home with his or her toothbrush.
Prognosis:
If people have 7-mm or deeper pockets around their teeth, then they would likely risk eventual tooth loss over the years. If this periodontal condition is not identified and people remain unaware of the progressive nature of the disease, then years later, they may be surprised that some teeth will gradually become loose and may need to be extracted, sometimes due to a severe infection or even pain.
Prognosis:
According to the Sri Lankan tea laborer study, in the absence of any oral hygiene activity, approximately 10% will experience severe periodontal disease with rapid loss of attachment (>2 mm/year). About 80% will experience moderate loss (1–2 mm/year) and the remaining 10% will not experience any loss.
Epidemiology:
Periodontitis is very common, and is widely regarded as the second most common dental disease worldwide, after dental decay, and in the United States has a prevalence of 30–50% of the population, but only about 10% have severe forms.
Epidemiology:
Chronic periodontitis affects about 750 million people or about 10.8% of the world population as of 2010.Like other conditions intimately related to access to hygiene and basic medical monitoring and care, periodontitis tends to be more common in economically disadvantaged populations or regions. Its occurrence decreases with a higher standard of living. In Israeli populations, individuals of Yemenite, North-African, South Asian, or Mediterranean origin have higher prevalence of periodontal disease than individuals from European descent. Periodontitis is frequently reported to be socially patterned, i.e. people from the lower end of the socioeconomic scale are affected more often than people from the upper end of the socioeconomic scale.
History:
An ancient hominid from 3 million years ago had gum disease. Records from China and the Middle East, along with archaeological studies, show that mankind has had periodontal disease for at least many thousands of years. In Europe and the Middle East archaeological research looking at ancient plaque DNA, shows that in the ancient hunter-gatherer lifestyle there was less gum disease, but that it became more common when more cereals were eaten. The Otzi Iceman was shown to have had severe gum disease. Furthermore, research has shown that in the Roman era in the UK, there was less periodontal disease than in modern times. The researchers suggest that smoking may be a key to this.
Society and culture:
Etymology The word "periodontitis" (Greek: περιοδοντίτις) comes from the Greek peri, "around", odous (GEN odontos), "tooth", and the suffix -itis, in medical terminology "inflammation". The word pyorrhea (alternative spelling: pyorrhoea) comes from the Greek pyorrhoia (πυόρροια), "discharge of matter", itself from pyon, "discharge from a sore", rhoē, "flow", and the suffix -ia. In English this term can describe, as in Greek, any discharge of pus; i.e. it is not restricted to these diseases of the teeth.
Society and culture:
Economics It is estimated that lost productivity due to severe periodontitis costs the global economy about US$54 billion each year.
Other animals:
Periodontal disease is the most common disease found in dogs and affects more than 80% of dogs aged three years or older. Its prevalence in dogs increases with age, but decreases with increasing body weight; i.e., toy and miniature breeds are more severely affected. Recent research undertaken at the Waltham Centre for Pet Nutrition has established that the bacteria associated with gum disease in dogs are not the same as in humans. Systemic disease may develop because the gums are very vascular (have a good blood supply). The blood stream carries these anaerobic micro-organisms, and they are filtered out by the kidneys and liver, where they may colonize and create microabscesses. The microorganisms traveling through the blood may also attach to the heart valves, causing vegetative infective endocarditis (infected heart valves). Additional diseases that may result from periodontitis include chronic bronchitis and pulmonary fibrosis. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Certance**
Certance:
Certance, LLC, was a privately held company engaged in design and manufacture of computer tape drives. Based in Costa Mesa, California, Certance designed and manufactured drives using a variety of tape formats, including Travan, DDS, and Linear Tape-Open computer tape drives. Certance was one of the three original technology partners, (Certance, IBM, and Hewlett-Packard), that created the Linear Tape-Open technology. In 2005, Certance was acquired by Quantum Corporation.
History:
The company began as the removable storage systems division of Seagate Technology. The division was formed in 1996 from storage companies Archive Corporation, Irwin Magnetic Systems, Cipher Data Products, and Maynard Electronics. In a restructuring involving Seagate Technology and Veritas Software, the division was spun off in 2000 into the independent company Seagate Removable Storage Systems. The company was the worldwide unit volume shipment leader in 2001, 2002, and 2003.The company name was changed to "Certance" in 2003. In 2004, Quantum Corporation announced plans to acquire Certance. The acquisition was completed in 2005, whereupon Certance ceased to exist as an independent company. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Zeroth-order logic**
Zeroth-order logic:
Zeroth-order logic is a branch of logic without variables or quantifiers. Some authors use the phrase "zeroth-order logic" as a synonym for the propositional calculus, but an alternative definition extends propositional logic by adding constants, operations, and relations on non-Boolean values. Every zeroth-order language in this broader sense is complete and compact. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Position line**
Position line:
A position line or line of position (LOP) is a line (or, on the surface of the earth, a curve) that can be both identified on a chart (nautical chart or aeronautical chart) and translated to the surface of the earth. The intersection of a minimum of two position lines is a fix that is used in position fixing to identify a navigator's location.
Position line:
There are several types of position line: Compass bearing – the angle between north and the line passing through the compass and the point of interest Transit – a line passing through the observer and two other reference points Leading line – the line passing through two marks indicating a safe channel Leading lights – the line passing through two beacons indicating a safe channel Sector lights – the lines created by masked colored lights that indicate a safe channel | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Through line**
Through line:
A through line is a connecting theme or plot used in media such as films and books. It is sometimes also called the 'spine', and was first suggested by Konstantin Stanislavski as a simplified way for actors to think about characterization. He believed actors should not only understand what their character was doing, or trying to do (their objective), in any given unit, but should also strive to understand the through line that linked these objectives together and thus pushed the character forward through the narrative.
Through line:
Through line is increasingly being used in other contexts as substitutes for words like thread, as seen in the following excerpt from an article by Alex Knapp: "There is a constant through line we see starting with A New Hope and running through to the end of the Return of the Jedi of the Emperor consolidating more and more power into his own hands and that of his right-hand man, Darth Vader." | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Audio tour**
Audio tour:
An audio tour or audio guide provides a recorded spoken commentary, normally through a handheld device, to a visitor attraction such as a museum. They are also available for self-guided tours of outdoor locations, or as a part of an organised tour. It provides background, context, and information on the things being viewed. Audio guides are often in multilingual versions and can be made available in different ways. Some of the more elaborate tours may include original music and interviews. They are traditionally rented on the spot, more recently downloaded from the Internet, or available via the mobile phone network. Some audio guides are free or included in the entrance fee, others have to be purchased separately.
History:
Willem Sandberg, director of the Stedelijk Museum in Amsterdam from 1945 to 1962, pioneered the world's first museum audio tours. When invented in 1952, the developers were drawn by its unique potential to mediate an experience individually controllable by each visitor, which was content-rich, was personal to them, was available at any time, and suited learning styles not served by catalog, text panel, or label.
History:
Sandberg's ambulatory lectures were delivered through a closed-circuit shortwave radio broadcasting system in which the amplified audio output of an analog playback tape recorder served as a broadcast station, and transmission was via a loop aerial fixed around the gallery or galleries. Identical lectures in Dutch, French, English, and German were recorded onto magnetic tapes, broadcast in turn through the aerial, and picked up by visitors through a portable radio receiver with headphones, when inside the loop.
History:
The system was such that all visitors with a receiver could only hear a specific piece of commentary at any time; hence, groups of visitors would move through the galleries and look at exhibits as if guided by an invisible force, in complete synchronicity.
Electronic multimedia guides:
A multimedia electronic guide is a device specially designed to provide audio, visual or textual content to museum visitors with or without user interaction. It may also provide alternative content corresponding to different personal preferences. It may include accessories such as headphones, a digital pen and displays with LEDs or LCD screens.
Electronic multimedia guides:
These smart guides may be operated to supply content in different languages and accents, with different voice alternatives, with text, and with age group specific content. They can be operated in several ways: Touch/push-button systems are operated by the visitor. The visitor enters the code assigned to the object or location to the electronic museum guide and the related content is provided.
Electronic multimedia guides:
Location aware systems operate semi-automatically. They sense the location by several alternative technologies and provide the related content. If the sensing area is not narrow enough to detect every different object then the visitor will enter or select the content he or she wants. Location aware systems provides better quality tours to disabled people.
Electronic multimedia guides:
Line of Sight Aware Systems operate automatically. They sense the location and the target object and provides the related content. These systems may include software that will attempt to measure the visitor's aims and interest areas and may provide shallower or deeper information for the object. These systems may need special technologies for target detection.These electronic guides can provide the museum management with useful statistics and reports, which may include tour statistics, visitor statistics, opinions, and other surveys.
Cell phone tours:
A cell phone tour is an audio tour where pre-recorded or stream audio interpretation for a heritage site or a cultural exhibit is provided via a cell phone. Cell phone audio tours have the advantage that most visitors already have the equipment needed to take the audio tour, being their cell phones.
Cell phone tours:
Each venue is assigned a phone number with appropriate stop numbers, displayed next to the exhibit. Once a visitor has dialed in, they will be prompted and can enter the corresponding stop number of the exhibit they’re viewing, to hear the recorded content. These tours also enable the visitors to: fast forward, rewind, pause, as well as leave a feedback message for each exhibit or the whole tour; simply by pressing a number. In addition to audio content, some providers are also able to stream video, and text message recent visitors with updates. This is the old-style approach, not used widely.
Smartphone tours:
Smartphones have significant advantages over cell phones, as they have story-triggering technologies (GPS, bluetooth, NFC, QR-code scanner) and can use the power of mobile apps to deliver the right story in the right language in the right place and in the right context (e.g. the evening tour, or a winter tour). Stories could be adjusted to the pace and mood of the user. Of course, such guided tours will use other types of content, above audio: photo, texts, video, quests. Such apps can work online and offline.
Smartphone tours:
Smartphone tours could guide the user outdoor (streets, highways, zoos, parks, archaeological sites) and indoor (museums), using different guiding techniques.
Smartphone tours:
The museum market changesMuseums can publish guided tours in an hour and change it at any moment. The audio guide is not anymore a one-time-off project Museums finally own the content they develop (in the age of hardware audio guides museums rarely owned the content) Museums can go outside and provide tours for the city Museums can cooperate with other cultural institutions Museums can invite people from the local communities to help them to develop stories (i.e. leverage the crowdsourcing) Museums can finally invade the tourism market and carry on their educational mission on tourists With a new voice, with other museums, with crowdsourced projects, with co-operation with tourism and universities, museums can apply for large grants from public fundsThe tourism market changesCities can control the tourist's traffic, e.g. send tourists away from the city center From the other side, the small cities around big ones can get some tourists by providing guided tours Cities can enrich the rent-a-bike/boat/car experience with storytelling Cities may help tourists to "feel like local" with the help of local communities In the city context, museums and story developers can enjoy local businesses to promote their tours and stories for free, as such tours bring extra value for the users of such businesses. E.g. public transport, mobile operators, hotels, rental services are happy to promote the tours in the vicinity. It is called the Storytelling Smart City concept.The modern technology implicationsSelf-driving cars introduce an opportunity to make mobile storytelling a part of car infotainment system. Passengers will get stories on the roads (presumably for free).
Smartphone tours:
Personal assistant apps like Apple Siri or Google Assistant will use location-based stories as well. Being the audio-based apps, such assistants do need audio-based and location-based content. Development of "storytelling capacity" for Voice Assistants will be a powerful driver for raising public interest to Mobile Storytelling and attract more storytellers and funds.
Latest evolution of smartphone tours:
Given the low download rate of single use native mobile apps, partly due to app fatigue, in recent years museums have been following a growing trend to offer Progressive web applications (PWAs) or Web applications that can be accessed via QR-code without the need to download any app. One of the problems of those browser-based smartphone tours is the difficulty of monetizing them. To solve this problem, some companies resort to unique codes that must be entered into the web-app and expire after a certain period of time, or to non-transferable but reusable unique codes printed on a card that anonymously recognize the device used by the visitor. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Constantan**
Constantan:
Constantan is a proprietary name for a copper–nickel alloy also known as Eureka, Advance, and Ferry. It usually consists of 55% copper and 45% nickel. Its main feature is the low thermal variation of its resistivity, which is constant over a wide range of temperatures. Other alloys with similarly low temperature coefficients are known, such as manganin (Cu [86%] / Mn [12%] / Ni [2%] ).
History:
In 1887, Edward Weston discovered that metals can have a negative temperature coefficient of resistance, inventing what he called his "Alloy No. 2." It was produced in Germany where it was renamed "Konstantan".
Constantan alloy:
Of all alloys used in modern strain gauges, constantan is the oldest, and still the most widely used. This situation reflects the fact that constantan has the best overall combination of properties needed for many strain gauge applications. This alloy has, for example, an adequately high strain sensitivity, or gauge factor, which is relatively insensitive to strain level and temperature. Its resistivity (4.9 x 10−7 Ω·m) is high enough to achieve suitable resistance values in even very small grids, and its temperature coefficient of resistance is fairly low. In addition, constantan is characterized by a good fatigue life and relatively high elongation capability. However, constantan tends to exhibit a continuous drift at temperatures above 65 °C (149 °F); and this characteristic should be taken into account when zero stability of the strain gauge is critical over a period of hours or days. Constantan is also used for electrical resistance heating and thermocouples.
A-alloy:
Very importantly, constantan can be processed for self-temperature compensation to match a wide range of test material coefficients of thermal expansion. A-alloy is supplied in self-temperature-compensation (S-T-C) numbers 00, 03, 05, 06, 09, 13, 15, 18, 30, 40, and 50, for use on test materials with corresponding thermal expansion coefficients, expressed in parts per million by length (or μm/m) per degrees Fahrenheit.
P alloy:
For the measurement of very large strains, 5% (50,000 microstrain) or above, annealed constantan (P alloy) is the grid material normally selected. Constantan in this form is very ductile; and, in gauge lengths of 0.125 inches (3.2 mm) and longer, can be strained to >20%. It should be borne in mind, however, that under high cyclic strains the P alloy will exhibit some permanent resistivity change with each cycle, and cause a corresponding zero shift in the strain gauge. Because of this characteristic and the tendency for premature grid failure with repeated straining, P alloy is not ordinarily recommended for cyclic strain applications. P alloy is available with S-T-C numbers of 08 and 40 for use on metals and plastics, respectively.
Temperature measurement:
Constantan is also used to form thermocouples with wires made of iron, copper, or chromel. It has an extraordinarily strong negative Seebeck coefficient above 0 degrees Celsius, leading to a good temperature sensitivity. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Admittance parameters**
Admittance parameters:
Admittance parameters or Y-parameters (the elements of an admittance matrix or Y-matrix) are properties used in many areas of electrical engineering, such as power, electronics, and telecommunications. These parameters are used to describe the electrical behavior of linear electrical networks. They are also used to describe the small-signal (linearized) response of non-linear networks. Y parameters are also known as short circuited admittance parameters. They are members of a family of similar parameters used in electronic engineering, other examples being: S-parameters, Z-parameters, H-parameters, T-parameters or ABCD-parameters.
The Y-parameter matrix:
A Y-parameter matrix describes the behaviour of any linear electrical network that can be regarded as a black box with a number of ports. A port in this context is a pair of electrical terminals carrying equal and opposite currents into and out of the network, and having a particular voltage between them. The Y-matrix gives no information about the behaviour of the network when the currents at any port are not balanced in this way (should this be possible), nor does it give any information about the voltage between terminals not belonging to the same port. Typically, it is intended that each external connection to the network is between the terminals of just one port, so that these limitations are appropriate.
The Y-parameter matrix:
For a generic multi-port network definition, it is assumed that each of the ports is allocated an integer n ranging from 1 to N, where N is the total number of ports. For port n, the associated Y-parameter definition is in terms of the port voltage and port current, Vn and In respectively.
The Y-parameter matrix:
For all ports the currents may be defined in terms of the Y-parameter matrix and the voltages by the following matrix equation: I=YV where Y is an N × N matrix the elements of which can be indexed using conventional matrix notation. In general the elements of the Y-parameter matrix are complex numbers and functions of frequency. For a one-port network, the Y-matrix reduces to a single element, being the ordinary admittance measured between the two terminals.
Two-port networks:
The Y-parameter matrix for the two-port network is probably the most common. In this case the relationship between the port voltages, port currents and the Y-parameter matrix is given by: 11 12 21 22 )(V1V2) .where 11 12 21 22 =I2V2|V1=0 For the general case of an n-port network, for k≠m Admittance relations The input admittance of a two-port network is given by: 11 12 21 22 +YL where YL is the admittance of the load connected to port two.
Two-port networks:
Similarly, the output admittance is given by: 22 12 21 11 +YS where YS is the admittance of the source connected to port one.
Relation to S-parameters:
The Y-parameters of a network are related to its S-parameters by Y=y(IN−S)(IN+S)−1y=y(IN+S)−1(IN−S)y and S=(IN−zYz)(IN+zYz)−1=(IN+zYz)−1(IN−zYz) where IN is the identity matrix, y is a diagonal matrix having the square root of the characteristic admittance (the reciprocal of the characteristic impedance) at each port as its non-zero elements, 01 02 ⋱y0N) and z=(y)−1 is the corresponding diagonal matrix of square roots of characteristic impedances. In these expressions the matrices represented by the bracketed factors commute and so, as shown above, may be written in either order.
Relation to S-parameters:
Two port In the special case of a two-port network, with the same and real characteristic admittance 01 02 =Y0 at each port, the above expressions reduce to 11 11 22 12 21 12 12 21 21 22 11 22 12 21 ΔSY0 where 11 22 12 21 .
The above expressions will generally use complex numbers for Sij and Yij . Note that the value of Δ can become 0 for specific values of Sij so the division by Δ in the calculations of Yij may lead to a division by 0.
The two-port S-parameters may also be obtained from the equivalent two-port Y-parameters by means of the following expressions.
11 11 22 12 21 12 12 21 21 22 11 22 12 21 Δ where 11 22 12 21 and Z0 is the characteristic impedance at each port (assumed the same for the two ports).
Relation to Z-parameters:
Conversion from Z-parameters to Y-parameters is much simpler, as the Y-parameter matrix is just the inverse of the Z-parameter matrix. The following expressions show the applicable relations: 11 22 12 12 21 21 22 11 |Z| where 11 22 12 21 In this case |Z| is the determinant of the Z-parameter matrix.
Vice versa the Y-parameters can be used to determine the Z-parameters, essentially using the same expressions since Y=Z−1 and Z=Y−1. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**GNU Compiler for Java**
GNU Compiler for Java:
The GNU Compiler for Java (GCJ) is a discontinued free compiler for the Java programming language. It was part of the GNU Compiler Collection.GCJ compiles Java source code to Java virtual machine (JVM) bytecode or to machine code for a number of CPU architectures. It could also compile class files and whole JARs that contain bytecode into machine code.
History:
The GCJ runtime-libraries original source is from GNU Classpath project, but there is a code difference between the libgcj libraries. GCJ 4.3 uses the Eclipse Compiler for Java as a front-end.In 2007, a lot of work was done to implement support for Java's two graphical APIs in GNU Classpath: AWT and Swing. Software support for AWT is still in development. "Once AWT support is working then Swing support can be considered. There is at least one free-software partial implementations of Swing that may be usable.". The GNU CLASSPATH was never completed to even Java 1.2 status and now appears to have been abandoned completely.
History:
As of 2015, there were no new developments announced from GCJ and the product was in maintenance mode, with open-source Java toolchain development mostly happening within OpenJDK. GCJ was removed from the GCC trunk on September 30, 2016. Announcement of its removal was made with the release of the GCC 7.1, which does not contain it. GCJ remains part of GCC 6.
Performance:
The compilation function in GCJ should have a faster start-up time than the equivalent bytecode launched in a JVM when compiling Java code into machine code.
Compiled Native Interface (CNI):
The Compiled Native Interface (CNI), previously named "Cygnus Native Interface", is a software framework for the GCJ that allows Java code to call, and be called by, native applications (programs specific to a hardware and operating-system platform) and libraries written in C++.
CNI closely resembles the JNI (Java Native Interface) framework which comes as a standard with various Java virtual machines.
Compiled Native Interface (CNI):
Comparison of language use The authors of CNI claim for various advantages over JNI: We use CNI because we think it is a better solution, especially for a Java implementation that is based on the idea that Java is just another programming language that can be implemented using standard compilation techniques. Given that, and the idea that languages implemented using Gcc should be compatible where it makes sense, it follows that the Java calling convention should be as similar as practical to that used for other languages, especially C++, since we can think of Java as a subset of C++. CNI is just a set of helper functions and conventions built on the idea that C++ and Java have the *same* calling convention and object layout; they are binary compatible. (This is a simplification, but close enough.) CNI depends on Java classes appearing as C++ classes. For example, given a Java class, one can use the class thus: | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**IEFBR14**
IEFBR14:
IEFBR14 is an IBM mainframe utility program. It runs in all IBM mainframe environments derived from OS/360, including z/OS. It is a placeholder that returns the exit status zero, similar to the true command on UNIX-like systems.
Purpose:
Allocation (also called Initiation) On OS/360 and derived mainframe systems, most programs never specify files (usually called datasets) directly, but instead reference them indirectly through the Job Control Language (JCL) statements that invoke the programs. These data definition (or "DD") statements can include a "disposition" (DISP=...) parameter that indicates how the file is to be managed — whether a new file is to be created or an old one re-used; and whether the file should be deleted upon completion or retained; etc.
Purpose:
IEFBR14 was created because while DD statements can create or delete files easily, they cannot do so without a program to be run due to a certain peculiarity of the Job Management system, which always requires that the Initiator actually execute a program, even if that program is effectively a null statement. The program used in the JCL does not actually need to use the files to cause their creation or deletion — the DD DISP=... specification does all the work. Thus a very simple do-nothing program was needed to fill that role.
Purpose:
IEFBR14 can thus be used to create or delete a data set using JCL.
Purpose:
Deallocation (also called Termination) A secondary reason to run IEFBR14 was to unmount devices (usually tapes or disks) that had been left mounted from a previous job, perhaps because of an error in that job's JCL or because the job ended in error. In either event, the system operators would often need to demount the devices, and a started task – DEALLOC – was often provided for this purpose.
Purpose:
Simply entering the command S DEALLOC at the system console would run the started task, which consisted of just one step. However, due to the design of Job Management, DEALLOC must actually exist in the system's procedure library, SYS1.PROCLIB, lest the start command fail.
Also, all such started tasks must be a single jobstep as the "Started Task Control" (STC) module within the Job Management component of the operating system only accepts single-step jobs, and it fails all multi-step jobs, without exception.
//STEP01 EXEC PGM=IEFBR14 Parsing and validation At least on z/OS, branching off to execute another program would cause the calling program to be evaluated for syntax errors at that point.
Naming:
The "IEF" derives from a convention on mainframe computers that programs supplied by IBM were grouped together by function or creator and that each group shared a three-letter prefix. In OS/360, the first letter was almost always "I", and the programs produced by the Job Management group (including IEFBR14) all used the prefix "IEF". Other common prefixes included "IEB" for dataset utility programs, "IEH" for system utility programs, and "IEW" for program linkage and loading. Other major components were (and still are) "IEA" (Operating System Supervisor) and "IEC" (Input/Output Supervisor).
Naming:
As explained below, "BR 14" was the essential function of the program, to simply return to the operating system. This portion of a program name was often mnemonic — for example, IEBUPDTE was the dataset utility (IEB) that applied updates (UPDTE) to source code files, and IEHINITT was the system utility (IEH) that initialized (INIT) magnetic tape labels (T).
As explained further in "Usage" below, the name "BR14" comes from the IBM assembler-language instruction "Branch (to the address in) Register 14", which by convention is used to "return from a subroutine". Most early users of OS/360 were familiar with IBM Assembler Language and would have recognized this at once.
Usage:
Example JCL would be : To create a Partitioned Data Set:
Implementation:
IEFBR14 consisted initially of a single instruction a "Branch to Register" 14. The mnemonic used in the IBM Assembler was BR and hence the name: IEF BR 14. BR 14 is identically equivalent to BCR 15,14 (Branch Always [ mask = 15 = always ] to the address contained in general purpose register 14). BR is a pseudo instruction for BCR 15. The system assembler accepts many cases of such pseudo-instructions, as logical equivalents to the canonical System/360 instructions. The canonical instance of BR 14 is BCR 15,14.
Implementation:
The linkage convention for OS/360 and its descendants requires that a program be invoked with register 14 containing the address to return control to when complete, and register 15 containing the address at which the called program is loaded into memory; at completion, the program loads a return code in register 15, and then branches to the address contained in register 14. But, initially IEFBR14 was not coded with these characteristics in mind, as IEFBR14 was initially used as a dummy control section, one which simply returned to the caller, not as an executable module.
Implementation:
The original version of the program did not alter register 15 at all as its original application was as a placeholder in certain load modules which were generated during Sysgen (system generation), not as an executable program, per se. Since IEFBR14 was always invoked by the functional equivalent of the canonical BALR 14,15 instruction, the return code in register 15 was always non-zero. Later, a second instruction was to be added to clear the return code so that it would exit with a determinate status, namely zero. Initially, programmers were not using all properties of the Job Control Language, anyway, so an indeterminate return code was not a problem. However, subsequently programmers were indeed using these properties, so a determinate status became mandatory. This modification to IEFBR14 did not in any way impact its original use as a placeholder.
Implementation:
The machine code for the modified program is: SR R15,R15 put zero completion code into register 15 BR R14 branch to the address in register 14 (which is actually an SVC 3 instruction in the Communications Vector Table) The equivalent machine code, eliminating the BR for clarity, is: SR R15,R15 put zero completion code into register 15 SVC 3 issue EXIT SVC to terminate the jobstep This makes perfect sense as the OS/360 Initiator initially "attaches" the job-step task using the ATTACH macro-instruction (SVC 42), and "unwinding" the effect of this ATTACH macro (it being a Type 2 SVC instruction) must be a complementary instruction, namely an EXIT macro (necessarily a Type 1 SVC instruction, SVC 3). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Group Shot**
Group Shot:
Group Shot is a photo combining program developed by Microsoft Research. Its purpose is to solve the problem of individuals in group photographs that might be doing undesirable things such as looking elsewhere, closing their eyes, not smiling, etc. The principle of Group Shot is that multiple group photographs will be taken in each session. Multiple images from a session are loaded into the application, and then the user selects the best parts from all of the different photos and merges them into one.
Group Shot:
It was announced in Bill Gates' keynote at the 2007 Consumer Electronics Show. For a time, the software was available to download for Windows XP users, however it was later removed from the Microsoft Research website, and the project was officially closed. Microsoft Research stated that the beta period has expired.The Group Shot engine was eventually included in Windows Live Photo Gallery Wave 4 under the name of Photo Fuse.A similar feature is available in Adobe Photoshop Elements 6.0 under the name 'Photomerge Group Shot'. Essentially the same functionality is also available in Adobe Photoshop CS3's Photomerge, though not packaged as a separate feature. It is available as well in the open-source application Hugin and the Samsung Galaxy Camera.
Group Shot:
In January 2012, a GroupShot mobile app was released by Macadamia Apps allowing users to create a group image from multiple similar images on their mobile phone. The app is available for download in the iTunes App Store.
Group Shot:
In April 2016, DEVART, the Netherlands introduced a mobile app for iPhone called Snaptric that uses a new hi-tech seam technique enabling users to replace faces in a set of group photos with the same background and people. It does not simply replace the face but makes a nice seam through the original and replacement photos so that the new face blends seamlessly with the background. Users can preview their result in real time, without hassle with layers and traditional Photo-editor procedures. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Phenylalanine adenylyltransferase**
Phenylalanine adenylyltransferase:
In enzymology, a phenylalanine adenylyltransferase (EC 2.7.7.54) is an enzyme that catalyzes the chemical reaction ATP + L-phenylalanine ⇌ diphosphate + N-adenylyl-L-phenylalanineThus, the two substrates of this enzyme are ATP and L-phenylalanine, whereas its two products are diphosphate and N-adenylyl-L-phenylalanine.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is ATP:L-phenylalanine adenylyltransferase. This enzyme is also called L-phenylalanine adenylyltransferase. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Sodium polysulfide**
Sodium polysulfide:
Sodium polysulfide is a general term for salts with the formula Na2Sx, where x = 2 to 5. The species Sx2−, called polysulfide anions, include disulfide (S22−), trisulfide (S32−), tetrasulfide (S42−), and pentasulfide (S52−). In principle, but not in practice, the chain lengths could be longer. The salts are dark red solids that dissolve in water to give highly alkaline and corrosive solutions. In air, these salts oxidize, and they evolve hydrogen sulfide by hydrolysis.
Structure:
The polysulfide anions form chains with S---S bond distances around 2 Å in length. The chains adopt skewed conformations. In the solid state, these salts are dense solids with strong association of the sodium cations with the anionic termini of the chains.
Production and occurrence:
Sodium polysulfide can be produced by dissolving sulfur in a solution of sodium sulfide. Alternatively they are produced by the redox reaction of aqueous sodium hydroxide with sulfur at elevated temperatures. Finally they arise by the reduction of elemental sulfur with sodium, a reaction often conducted in anhydrous ammonia.
These salts are used in the production of polysulfide polymers, as a chemical fungicide, as a blackening agent on copper jewellery, as a component in a polysulfide bromide battery, as a toner in a photochemical solution, and in the tanning industry to remove hair from hides.
Reactions:
As exploited in the sodium-sulfur battery, the polysulfides absorb and release reducing equivalents by breaking and making S-S bonds, respectively. An idealized reaction for sodium tetrasulfide is shown: Na2S4 + 2 Na ⇌ 2 Na2S2Alkylation gives organic polysulfides according to the following idealized equation: Na2S4 + 2 RX → 2 NaX + R2S4Alkylation with an organic dihalide gives polymers called thiokols.
Reactions:
Protonation of these salts gives hydrogen sulfide and elemental sulfur, as illustrated by the reaction of sodium pentasulfide: Na2S5 + 2 HCl → H2S + 4 S + 2 NaCl | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Stone–Wales defect**
Stone–Wales defect:
A Stone–Wales defect is a crystallographic defect that involves the change of connectivity of two π-bonded carbon atoms, leading to their rotation by 90° with respect to the midpoint of their bond. The reaction commonly involves conversion between a naphthalene-like structure into a fulvalene-like structure, that is, two rings that share an edge vs two separate rings that have vertices bonded to each other.
Stone–Wales defect:
The reaction occurs on carbon nanotubes, graphene, and similar carbon frameworks, where the four adjacent six-membered rings of a pyrene-like region are changed into two five-membered rings and two seven-membered rings when the bond uniting two of the adjacent rings rotates. In these materials, the rearrangement is thought to have important implications for the thermal, chemical, electrical, and mechanical properties. The rearrangement is an example of a pyracyclene rearrangement.
History:
The defect is named after Anthony Stone and David J. Wales at the University of Cambridge, who described it in a 1986 paper on the isomerization of fullerenes. However, a similar defect was described much earlier by G. J. Dienes in 1952 in a paper on diffusion mechanisms in graphite and later in 1969 in a paper on defects in graphite by Peter Thrower. For this reason, the term Stone–Thrower–Wales defect is sometimes used.
Structural effects:
The defects have been imaged using scanning tunneling microscopy and transmission electron microscopy and can be determined using various vibrational spectroscopy techniques.It has been proposed that the coalescence process of fullerenes or carbon nanotubes may occur through a sequence of such a rearrangements. The defect is thought to be responsible for nanoscale plasticity and the brittle–ductile transitions in carbon nanotubes.
Chemical details:
The activation energy for the simple atomic motion that gives the bond-rotation apparent in a Stone–Wales defects is fairly high—a barrier of several electronvolts. but various processes can create the defects at substantially lower energies than might be expected.The rearrangement creates a structure with less resonance stabilization among the sp2 atoms involved and higher strain energy in the local structure. As a result, the defect creates a region with greater chemical reactivity, including acting as a nucleophile and creating a preferred site for binding to hydrogen atoms. The high affinity of these defects for hydrogen, coupled with the large surface area of the bulk material, might make these defects an important aspect in the use of carbon nanomaterials for hydrogen storage. Incorporation of defects along a carbon-nanotube network can program a carbon-nanotube circuit to enhance the conductance along a specific path. In this scenario, the defects lead to a charge delocalization, which redirects an incoming electron down a given trajectory. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**2002 RN109**
2002 RN109:
2002 RN109 is a trans-Neptunian object and damocloid on a highly eccentric, cometary-like orbit. It was first observed on 6 September 2002, by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Lab's ETS near Socorro, New Mexico, in the United States. The unusual object measures approximately 4 kilometers (2 miles) in diameter. It has the second highest orbital eccentricity of any known minor planet, after 2005 VX3.
Description:
2002 RN109 may be a dormant comet that has not been seen outgassing. In the past it may have made closer approaches to the Sun that could have removed most near-surface volatiles. It orbits the Sun at a distance of 2.7–1,091 AU once every 12783 years (semi-major axis of 546.7 AU). Its orbit has an eccentricity of 0.9951 and an inclination of 58° with respect to the ecliptic. The body's observation arc begins with a precovery observation at Lincoln Laboratory's Experimental Test Site on 16 August 2002, or three weeks prior to its first observation. The observation arc only spans over 80 days. The object has not been observed since November 2002 about 2 months before it came to perihelion 2.7 AU from the Sun. During perihelion passage the object was 2.9 AU from Earth.
Description:
2002 RN109 belongs to the dynamical group of damocloids due to its low Tisserand parameter (TJupiter of 1.0820). It is also a Jupiter-, Saturn-, Uranus-, and Neptune-crosser. The object has the seventh-largest heliocentric semi-major axis and aphelion of all known minor planets, while its extreme eccentricity brings it well within the orbit of Jupiter when at perihelion. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Rendiconti di Matematica e delle sue Applicazioni**
Rendiconti di Matematica e delle sue Applicazioni:
The Rendiconti di Matematica e delle sue Applicazioni (Reports on Mathematics and its applications) is an open access peer-reviewed mathematics journal, jointly published by the "Guido Castelnuovo" Department of Mathematics of the Sapienza University of Rome and by the Istituto Nazionale di Alta Matematica Francesco Severi, established in 1913. The Journal started his publications a year after, in 1914, and his first director was Vito Volterra.It publishes research articles in pure and applied mathematics, without imposing restrictions on the length of the work: for this reason, the submission of surveys, articles of foundational nature and doctoral dissertations is also encouraged. As in every peer reviewed journal, every article is refereed, and the journal adheres to the EMS Code of Practice.The journal is abstracted and indexed by Mathematical Reviews, Zentralblatt MATH and Scopus.
Historical notes:
Foundation and the first four series The journal was founded in 1913 as the press organ of the "Seminario Matematico della Facoltà di Scienze della Reale Uninversità di Roma": its first director (Editor in chief) was Vito Volterra, who held this position from its foundation to the year 1921. The direction passed to Guido Castelnuovo who held it from 1921 to 1922: with the beginning of and during the publishing of the whole second and third series of the journal, from 1922 to 1935 Federigo Enriques was the director. During fourth series of the journal, at the starting of which it underwent its first name change, the direction passed to Gaetano Scorza, who held it until his death in 1939.
Historical notes:
The INdAM and its influence The founding of the Istituto Nazionale di Alta Matematica in 1939, under the decisive influence of Francesco Severi, had important consequences on the "Rendiconti del Seminario Matematico". On 23 November 1939, during its first meeting, the Scientific Council of the then newborn institute, considering the need of a means to publish the results of the research done by the members and the students working at the institute, decided to merge the needed means and the already existing journal in one single entity, giving birth to the "Rendiconti di Matematica e delle sue Applicazioni". Entrusted with this double function the fifth series of the journal, from the first volume published in 1940 to the first issue of the fourth volume published in 1943, included a section listing the programs of the INdAM courses of the current academic year as well as section listing the research problems proposed by the lecturers currently working at the institute.
Historical notes:
Timeline of Journal series and editors in chief | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Suction pressure**
Suction pressure:
Suction pressure is also called Diffusion Pressure Deficit. If some solute is dissolved in solvent, its diffusion pressure decreases. The difference between diffusion pressure of pure solvent and solution is called diffusion pressure deficit (DPD). It is a reduction in the diffusion pressure of solvent in the solution over its pure state due to the presence of solutes in it and forces opposing diffusion. When a plant cell is placed in a hypotonic solution, water enters into a cell by endosmosis and as a result turgor pressure (TP) develops in the cell. The cell membrane becomes stretched and the osmotic pressure (OP) of the cell decreases. As the cell absorbs more and more water its turgor pressure increases and osmotic pressure decreases. When a cell is fully turgid, its OP is equal to TP and DPD is zero. Turgid cells cannot absorb any more water. Thus, with reference to plant cells, the DPD can be described as the actual thirst of a cell for water and can be expressed as : DPD=OP−TP Thus it is DPD that tends to equate and represents the water-absorbing ability of a cell, it is also called suction force (SF) or suction pressure (SP). The actual pressure with which a cell absorbs water is called "suction pressure".
Factors affecting DPD:
DPD is directly proportional to the height of the plant, tree or organism.
DPD is governed by two factors i.e. turgor pressure and osmotic pressure. Turgor pressure can be denoted as wall pressure in some cases.
DPD is directly proportional to the concentration of the solution. DPD decreases with dilution of the solution.
History:
The term diffusion pressure deficit (DPD) was coined by B.S. Meyer in 1938. Originally DPD was described as suction pressure by German botanist Otto Renner in 1915.
Refrigeration:
In refrigeration and air conditioning systems, the suction pressure' (also called the low-side pressure) is the intake pressure generated by the system compressor while operating. The suction pressure, along with the suction temperature the wet bulb temperature of the discharge air are used to determine the correct refrigerant charge in a system. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Sato–Tate conjecture**
Sato–Tate conjecture:
In mathematics, the Sato–Tate conjecture is a statistical statement about the family of elliptic curves Ep obtained from an elliptic curve E over the rational numbers by reduction modulo almost all prime numbers p. Mikio Sato and John Tate independently posed the conjecture around 1960.
If Np denotes the number of points on the elliptic curve Ep defined over the finite field with p elements, the conjecture gives an answer to the distribution of the second-order term for Np. By Hasse's theorem on elliptic curves, Np/p=1+O(1/p) as p→∞ , and the point of the conjecture is to predict how the O-term varies.
The original conjecture and its generalization to all totally real fields was proved by Laurent Clozel, Michael Harris, Nicholas Shepherd-Barron, and Richard Taylor under mild assumptions in 2008, and completed by Thomas Barnet-Lamb, David Geraghty, Harris, and Taylor in 2011. Several generalizations to other algebraic varieties and fields are open.
Statement:
Let E be an elliptic curve defined over the rational numbers without complex multiplication. For a prime number p, define θp as the solution to the equation cos θp(0≤θp≤π).
Then, for every two real numbers α and β for which 0≤α<β≤π, lim sin sin cos sin cos (β))
Details:
By Hasse's theorem on elliptic curves, the ratio (p+1)−Np2p=ap2p is between -1 and 1. Thus it can be expressed as cos θ for an angle θ; in geometric terms there are two eigenvalues accounting for the remainder and with the denominator as given they are complex conjugate and of absolute value 1. The Sato–Tate conjecture, when E doesn't have complex multiplication, states that the probability measure of θ is proportional to sin 2θdθ.
Details:
This is due to Mikio Sato and John Tate (independently, and around 1960, published somewhat later).
Proof:
In 2008, Clozel, Harris, Shepherd-Barron, and Taylor published a proof of the Sato–Tate conjecture for elliptic curves over totally real fields satisfying a certain condition: of having multiplicative reduction at some prime, in a series of three joint papers.Further results are conditional on improved forms of the Arthur–Selberg trace formula. Harris has a conditional proof of a result for the product of two elliptic curves (not isogenous) following from such a hypothetical trace formula. In 2011, Barnet-Lamb, Geraghty, Harris, and Taylor proved a generalized version of the Sato–Tate conjecture for an arbitrary non-CM holomorphic modular form of weight greater than or equal to two, by improving the potential modularity results of previous papers. The prior issues involved with the trace formula were solved by Michael Harris, and Sug Woo Shin.In 2015, Richard Taylor was awarded the Breakthrough Prize in Mathematics "for numerous breakthrough results in (...) the Sato–Tate conjecture."
Generalisations:
There are generalisations, involving the distribution of Frobenius elements in Galois groups involved in the Galois representations on étale cohomology. In particular there is a conjectural theory for curves of genus n > 1.
Under the random matrix model developed by Nick Katz and Peter Sarnak, there is a conjectural correspondence between (unitarized) characteristic polynomials of Frobenius elements and conjugacy classes in the compact Lie group USp(2n) = Sp(n). The Haar measure on USp(2n) then gives the conjectured distribution, and the classical case is USp(2) = SU(2).
Refinements:
There are also more refined statements. The Lang–Trotter conjecture (1976) of Serge Lang and Hale Trotter states the asymptotic number of primes p with a given value of ap, the trace of Frobenius that appears in the formula. For the typical case (no complex multiplication, trace ≠ 0) their formula states that the number of p up to X is asymptotically log X with a specified constant c. Neal Koblitz (1988) provided detailed conjectures for the case of a prime number q of points on Ep, motivated by elliptic curve cryptography.
Refinements:
In 1999, Chantal David and Francesco Pappalardi proved an averaged version of the Lang–Trotter conjecture. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Melomics**
Melomics:
Melomics (derived from "genomics of melodies") is a computational system for the automatic composition of music (with no human intervention), based on bioinspired algorithms.
Technological aspects:
Melomics applies an evolutionary approach to music composition, i.e., music pieces are obtained by simulated evolution. These themes compete to better adapt to a proper fitness function, generally grounded on formal and aesthetic criteria. The Melomics system encodes each theme in a genome, and the entire population of music pieces undergoes evo-devo dynamics (i.e., pieces read-out mimicking a complex embryological development process). The system is fully autonomous: once programmed, it composes music without human intervention.
Technological aspects:
This technology has been transferred to industry as an academic spin-off, Melomics Media, which has provided and reprogrammed a new computer cluster that created a huge collection of popular music. The results of this evolutionary computation are being stored in Melomics' site, which nowadays constitutes a vast repository of music content. A differentiating feature is that pieces are available in three types of formats: playable (MP3), editable (MIDI and MusicXML) and readable (score in PDF).
Computer clusters:
The Melomics computational system includes two computer clusters: Melomics109 and Iamus, dedicated to popular and artistic music, respectively.
Computer clusters:
Melomics109 cluster Melomics109 is cluster programmed and integrated in the Melomics system. Its first product is a vast repository of popular music compositions (roughly 1 billion), covering all essential styles. In addition to MP3, all songs are available in editable formats (MIDI); and music is licensed under CC0, meaning that it is freely downloadable.0music is the first album published by Melomics109, which is available in MP3 and MIDI formats, under CC0 license.
Computer clusters:
It has been argued that, by making such amount of editable, original and royalty-free music accessible to people, Melomics may accelerate the process of commoditization of music, and change the way music is composed and consumed in the future.
Computer clusters:
Iamus album In the first stages of the development of the Melomics system, Iamus composed Opus one (on October 15, 2010), arguably the first fragment of professional contemporary classical music ever composed by a computer in its own style, rather than attempting to emulate the style of existing composers. The first full composition (also in contemporary classic style), Hello World!, premiered exactly one year after the creation of Opus one, on October 15, 2011. Four later works premiered on July 2, 2012, and were broadcast live from the School of Computer Science at Universidad de Málaga as part of the events included in the Alan Turing year. The compositions performed at this event were before recorded at Real Conservatorio María Cristina, Málaga (Spain), March 2 to 3, 2012, and Angel Studios, London (UK) at April 14, 2012, by the London Symphony Orchestra, creating Iamus' eponymous first album, which New Scientist reported as the "first complete album to be composed solely by a computer and recorded by human musicians."Commenting on the quality and authenticity of the music, Stephen Smoliar, critic of classical music at The San Francisco Examiner, commented "What is primary is the act of making the music itself engaged by the performers and how the listener responds to what those performers do... what is most interesting about the documents generated by Iamus is their capacity to challenge the creative talents of performing musicians".
Applications:
Melomics' empathic music has been tested in a number of therapeutic clinical trials, evidencing positive effects in reducing fear of heights, acute stress and pain perception. One of the studies resulted in a reduction of almost two thirds of pain perception in children undergoing a standard Skin Prick Test during allergy testing, as compared to the standard procedure. Some of these experiments made use of free mobile apps to adapt music to daily activity, such as jogging, or commuting, but also for therapeutic use, such as lessening stress before an exam, reducing chronic pain, insomnia, and to help children go to sleep.Ongoing efforts to allow Melomics to adapt music in real-time to changes in the physiological state of the listener, and to music branding were also reported. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Graphics**
Graphics:
Graphics (from Ancient Greek γραφικός (graphikós) 'pertaining to drawing, painting, writing, etc.') are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone, to inform, illustrate, or entertain. In contemporary usage, it includes a pictorial representation of data, as in design and manufacture, in typesetting and the graphic arts, and in educational and recreational software. Images that are generated by a computer are called computer graphics.
Graphics:
Examples are photographs, drawings, line art, mathematical graphs, line graphs, charts, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings, or other images. Graphics often combine text, illustration, and color. Graphic design may consist of the deliberate selection, creation, or arrangement of typography alone, as in a brochure, flyer, poster, web site, or book without any other element. The objective can be clarity or effective communication, association with other cultural elements, or merely the creation of a distinctive style.
Graphics:
Graphics can be functional or artistic. The latter can be a recorded version, such as a photograph, or interpretation by a scientist to highlight essential features, or an artist, in which case the distinction with imaginary graphics may become blurred. It can also be used for architecture.
History:
The earliest graphics known to anthropologists studying prehistoric periods are cave paintings and markings on boulders, bone, ivory, and antlers, which were created during the Upper Palaeolithic period from 40,000 to 10,000 B.C. or earlier. Many of these were found to record astronomical, seasonal, and chronological details. Some of the earliest graphics and drawings are known to the modern world, from almost 6,000 years ago, are that of engraved stone tablets and ceramic cylinder seals, marking the beginning of the historical periods and the keeping of records for accounting and inventory purposes. Records from Egypt predate these and papyrus was used by the Egyptians as a material on which to plan the building of pyramids; they also used slabs of limestone and wood. From 600 to 250 BC, the Greeks played a major role in geometry. They used graphics to represent their mathematical theories such as the Circle Theorem and the Pythagorean theorem.
History:
In art, "graphics" is often used to distinguish work in a monotone and made up of lines, as opposed to painting.
Drawing Drawing generally involves making marks on a surface by applying pressure from a tool or moving a tool across a surface. In which a tool is always used as if there were no tools it would be art. Graphical drawing is an instrumental guided drawing.
Printmaking Woodblock printing, including images is first seen in China after paper was invented (about A.D. 105). In the West, the main techniques have been woodcut, engraving and etching, but there are many others.
History:
Etching Etching is an intaglio method of printmaking in which the image is incised into the surface of a metal plate using an acid. The acid eats the metal, leaving behind roughened areas, or, if the surface exposed to the acid is very thin, burning a line into the plate. The use of the process in printmaking is believed to have been invented by Daniel Hopfer (c. 1470–1536) of Augsburg, Germany, who decorated armour in this way.
History:
Etching is also used in the manufacturing of printed circuit boards and semiconductor devices.
Line art Line art is a rather non-specific term sometimes used for any image that consists of distinct straight and curved lines placed against a (usually plain) background, without gradations in shade (darkness) or hue (color) to represent two-dimensional or three-dimensional objects. Line art is usually monochromatic, although lines may be of different colors.
History:
Illustration An illustration is a visual representation such as a drawing, painting, photograph or other work of art that stresses subject more than form. The aim of an illustration is to elucidate or decorate a story, poem or piece of textual information (such as a newspaper article), traditionally by providing a visual representation of something described in the text. The editorial cartoon, also known as a political cartoon, is an illustration containing a political or social message.
History:
Illustrations can be used to display a wide range of subject matter and serve a variety of functions, such as: giving faces to characters in a story displaying a number of examples of an item described in an academic textbook (e.g. A Typology) visualizing step-wise sets of instructions in a technical manual communicating subtle thematic tone in a narrative linking brands to the ideas of human expression, individuality, and creativity making a reader laugh or smile for fun (to make laugh) funny Graphs A graph or chart is an graphic that represents tabular or numeric data. Charts are often used to make it easier to understand large quantities of data and the relationships between different parts of the data.
History:
Diagrams A diagram is a simplified and structured visual representation of concepts, ideas, constructions, relations, statistical data, etc., used to visualize and clarify the topic.
Symbols A symbol, in its basic sense, is a representation of a concept or quantity; i.e., an idea, object, concept, quality, etc. In more psychological and philosophical terms, all concepts are symbolic in nature, and representations for these concepts are simply token artifacts that are allegorical to (but do not directly codify) a symbolic meaning, or symbolism.
Maps A map is a simplified depiction of a space, a navigational aid which highlights relations between objects within that space. Usually, a map is a two-dimensional, geometrically accurate representation of a three-dimensional space.
One of the first 'modern' maps was made by Waldseemüller.
History:
Photography One difference between photography and other forms of graphics is that a photographer, in principle, just records a single moment in reality, with seemingly no interpretation. However, a photographer can choose the field of view and angle, and may also use other techniques, such as various lenses to choose the view or filters to change the colors. In recent times, digital photography has opened the way to an infinite number of fast, but strong, manipulations. Even in the early days of photography, there was controversy over photographs of enacted scenes that were presented as 'real life' (especially in war photography, where it can be very difficult to record the original events). Shifting the viewer's eyes ever so slightly with simple pinpricks in the negative could have a dramatic effect.
History:
The choice of the field of view can have a strong effect, effectively 'censoring out' other parts of the scene, accomplished by cropping them out or simply not including them in the photograph. This even touches on the philosophical question of what reality is. The human brain processes information based on previous experience, making us see what we want to see or what we were taught to see. Photography does the same, although the photographer interprets the scene for their viewer.
History:
Engineering drawings An engineering drawing is a type of drawing and is technical in nature, used to fully and clearly define requirements for engineered items. It is usually created in accordance with standardized conventions for layout, nomenclature, interpretation, appearance (such as typefaces and line styles), size, etc.
History:
Computer graphics There are two types of computer graphics: raster graphics, where each pixel is separately defined (as in a digital photograph), and vector graphics, where mathematical formulas are used to draw lines and shapes, which are then interpreted at the viewer's end to produce the graphic. Using vectors results in infinitely sharp graphics and often smaller files, but, when complex, like vectors take time to render and may have larger file sizes than a raster equivalent.
History:
In 1950, the first computer-driven display was attached to MIT's Whirlwind I computer to generate simple pictures. This was followed by MIT's TX-0 and TX-2, interactive computing which increased interest in computer graphics during the late 1950s. In 1962, Ivan Sutherland invented Sketchpad, an innovative program that influenced alternative forms of interaction with computers.
History:
In the mid-1960s, large computer graphics research projects were begun at MIT, General Motors, Bell Labs, and Lockheed Corporation. Douglas T. Ross of MIT developed an advanced compiler language for graphics programming. S.A.Coons, also at MIT, and J. C. Ferguson at Boeing, began work in sculptured surfaces. GM developed their DAC-1 system, and other companies, such as Douglas, Lockheed, and McDonnell, also made significant developments. In 1968, ray tracing was first described by Arthur Appel of the IBM Research Center, Yorktown Heights, N.Y.During the late 1970s, home computers became more powerful, capable of drawing both basic and complex shapes and designs. In the 1980s, artists and graphic designers began to see the personal computer as a serious design tool, one that could save time and draw more accurately than other methods.
History:
3D computer graphics began being used in video games in the 1970s with Spasim for the PLATO system in 1974 and FS1 Flight Simulator in 1979. Atari, Inc.'s Battlezone (1980) exposed 3D graphics to a wide audience. Other wireframe and flat-shaded 3D games appeared throughout the 1980s. Ultima Underworld: The Stygian Abyss (1992) was one of the first major video games with texture-mapped polygons.
History:
Computer systems dating from the 1980s and onwards often use a graphical user interface (GUI) to present data and information with symbols, icons, and pictures, rather than text. 3D computer graphics and creation tools became more accessible to video game and film developers in the late 1980s with SGI computers, which were later used to create some of the first fully computer-generated short films at Pixar.
History:
3D graphics became more popular in the 1990s in video games, multimedia, and animation. In 1995, Toy Story, the first full-length computer-generated animation film, was released in cinemas. Since then, computer graphics have become more accurate and detailed, due to more advanced computers and better 3D modeling software applications, such as Maya, 3D Studio Max, and Cinema 4D. Consumer-level 3D graphics acceleration hardware became common in IBM PC compatibles near the end of the decade.
History:
Another use of computer graphics is screensavers, originally intended to prevent the layout of much-used GUIs from 'burning into' the computer screen. They have since evolved into true pieces of art, their practical purpose obsolete; modern screens are not susceptible to such artifacts.
History:
Web graphics In the 1990s, Internet speeds increased, and Internet browsers capable of viewing images were released, the first being Mosaic. Websites began to use the GIF format to display small graphics, such as banners, advertisements, and navigation buttons, on web pages. Modern web browsers can now display JPEG, PNG and increasingly, SVG images in addition to GIFs on web pages. SVG, and to some extent VML, support in some modern web browsers have made it possible to display vector graphics that are clear at any size. Plugins expand the web browser functions to display animated, interactive and 3-D graphics contained within file formats such as SWF and X3D.
History:
Modern web graphics can be made with software such as Adobe Photoshop, the GIMP, or Corel Paint Shop Pro. Users of Microsoft Windows have MS Paint, which many find to be lacking in features. This is because MS Paint is a drawing package and not a graphics package.
History:
Numerous platforms and websites have been created to cater to web graphics artists and to host their communities. A growing number of people use create internet forum signatures—generally, appearing after a user's post—and other digital artwork, such as photo manipulations and large graphics. With computer games' developers creating their own communities around their products, many more websites are being developed to offer graphics for the fans and to enable them to show their appreciation of such games in their own gaming profiles.
Uses:
Graphics are visual elements often used to point readers and viewers to particular information. They are also used to supplement text in an effort to aid readers in their understanding of a particular concept or make the concept more clear or interesting. Popular magazines, such as Time, Wired and Newsweek, usually contain graphic material in abundance to attract readers, unlike the majority of scholarly journals. In computing, they are used to create a graphical interface for the user; and graphics are one of the five key elements of multimedia technology. Graphics are among the primary ways of advertising the sale of goods or services.
Uses:
Business Graphics are commonly used in business and economics to create financial charts and tables. The term business graphics came into use in the late 1970s, when personal computers became capable of drawing graphs and charts instead of using a tabular format. Business graphics can be used to highlight changes over time.
Advertising Advertising is one of the most profitable uses of graphics; artists often do advertising work or take advertising potential into account when creating art, to increase the chances of selling the artwork.
Most importantly, graphics give a good look to artwork whenever it is applied. Graphics contribute to the general outlook of a designed artwork, this, in turn, lure interested members of the public to look at the work of art or purchasing it.
Any graphical work (especially advertisement) or any work of art that is poorly designed will not persuade the audience. therefore, for an advertisement to persuade and convince readers or viewers, it must be well designed with needed graphical tools so as to bring profit to the designer or advertiser.
Uses:
Political The use of graphics for overtly political purposes—cartoons, graffiti, poster art, flag design, etc.—is a centuries-old practice which thrives today in every part of the world. The Northern Irish murals are one such example. A more recent example is Shepard Fairey's 2008 U.S. presidential election Barack Obama "Hope" poster. It was first published on the web, but soon found its way onto streets throughout the United States.
Uses:
Education Graphics are heavily used in textbooks, especially those concerning subjects such as geography, science, and mathematics, in order to illustrate theories and concepts, such as the human anatomy. Diagrams are also used to label photographs and pictures.
Educational animation is an important emerging field of graphics. Animated graphics have obvious advantages over static graphics when explaining subject matter that changes over time.
The Oxford Illustrated Dictionary uses graphics and technical illustrations to make reading material more interesting and easier to understand. In an encyclopedia, graphics are used to illustrate concepts and show examples of the particular topic being discussed.
In order for a graphic to function effectively as an educational aid, the learner must be able to interpret it successfully. This interpretative capacity is one aspect of graphicacy.
Film and animation Computer graphics are often used in the majority of new feature films, especially those with a large budget. Films that heavily use computer graphics include The Lord of the Rings film trilogy, the Harry Potter films, Spider-Man and War of the Worlds.
Graphics education:
The majority of schools, colleges, and universities around the world educate students on the subject of graphic design and art.
The subject is taught in a broad variety of ways, each course teaching its own distinctive balance of craft skills and intellectual response to the client's needs.
Graphics education:
Some graphics courses prioritize traditional craft skills—drawing, printmaking, and typography—over modern craft skills. Other courses may place an emphasis on teaching digital craft skills. Still, other courses may downplay the crafts entirely, concentrating on training students to generate novel intellectual responses that engage with the brief. Despite these apparent differences in training and curriculum, the staff and students on any of these courses will generally consider themselves to be graphic designers.
Graphics education:
The typical pedagogy of a graphic design (or graphic communication, visual communication, graphic arts or any number of synonymous course titles) will be broadly based on the teaching models developed in the Bauhaus school in Germany or Vkhutemas in Russia. The teaching model will tend to expose students to a variety of craft skills (currently everything from drawing to motion capture), combined with an effort to engage the student with the world of visual culture.
Noted graphic designers:
Aldus Manutius designed the first italic type style which is often used in desktop publishing and graphic design. April Greiman is known for her influential poster design. Paul Rand is well known as a design pioneer for designing many popular corporate logos, including the logo for IBM, NeXT and UPS. William Caslon, during the mid-18th century, designed many typefaces, including ITC Founder's Caslon, ITC Founder's Caslon Ornaments, Caslon Graphique, ITC Caslon No. 224, Caslon Old Face and Big Caslon. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Bowhunting**
Bowhunting:
Bowhunting (or bow hunting) is the practice of hunting game animals by archery. Many indigenous peoples have employed the technique as their primary hunting method for thousands of years, and it has survived into contemporary use for sport and hunting.
Modern history:
The last of the Yahi tribe, an indigenous man known as Ishi, came out of hiding in California in 1911. His doctor, Saxton Pope, learned many of Ishi's traditional archery skills, and popularized them. The Pope and Young Club, founded in 1961 and named in honor of Pope and his friend, Arthur Young, became one of North America's leading bowhunting and conservation organizations. Founded as a nonprofit scientific organization, the Club was patterned after the Boone and Crockett Club and advocated responsible bowhunting by promoting quality, fair chase hunting, and sound conservation practices. Modern game archery owes much of its success to Fred Bear, an American bow hunter and bow manufacturer.
Equipment:
Arrows, bows and sights are commonly of the more modern varieties. However, all effective variations, including crossbows and wooden bows launching wooden arrows with stone points, are used. Arrowheads are chosen to ensure lethality. Broadheads feature blades that jut out from the shaft at an angle to cause more damage to the target; some models have retractable blades that only deploy once they hit the target.
Equipment:
Big game hunting requires a draw weight of more than 35 pounds-force (16 kilograms-force). For larger game such as elk or moose, more than 50 lbf (23 kgf) is suggested. Most male American archers can draw a bow rated at 50–60 lbf (23–27 kgf), most women 30–40 lbf (14–18 kgf).Lighter arrows, all else equal, will give a higher speed and a flatter trajectory. Arrows with greater mass carry more momentum, and penetrate better in large animals; a minimum mass of 650 grains (40 grams) is recommended for animals such as deer, pigs, etc and 900 gr (60 g) for the largest game.
Methods of hunting:
In contrast to a rifle hunter, who may shoot effectively from ranges in excess of 200 yards (180 m); archers usually restrict shots to 2.3 to 42 yards (2 to 38 m). The distance depends upon individual ability, the target animal, the bow strength, terrain, arrow and weather. The bow hunter may walk along the ground slowly, looking for game and stalking it carefully in the final approach. This type of slow, methodical stalking, is called "spot and stalk." Hunters often wear camouflage clothing and walk upwind (with the wind in their face) so that game ahead of them cannot smell them.
Methods of hunting:
In "stand hunting," the hunter waits for game to come to them, usually near food, water, or known trails. Brush and other natural materials may be placed for cover, or a "ground blind" that looks like a camouflage tent may be used. They usually "pop" up and can be set up from folded in a few minutes. The hunter may wait on a wooden or metal stand elevated in a tree, from three to six meters (3.5 to 6.5 yd). Bowhunting for fish is called bowfishing. Bowfishing equipment usually adds a line attached to a spool or a reel as well as a specially designed, heavier, barbed arrow. Most bow-fishers do not use sights, but if they do have sights they are different from standard ones to allow for refraction.
Legal and cultural considerations:
Bowhunting often has different seasons and restrictions from firearm hunting, and they differ significantly between areas. Legal and cultural approaches specific to the area must be taken into consideration by the hunter.
Legal and cultural considerations:
Europe Nations including Denmark, France, Spain, Portugal, Italy, Hungary, Finland and Bulgaria use bow and arrow hunting as a hunting tool in modern game management. Some European countries, including the United Kingdom, prohibit bowhunting. Bowhunting, like target archery, was revived in the UK during the Victorian era, but has been banned since 1965. Recently a law was passed in Estonia that would allow bowhunting of small game.
Legal and cultural considerations:
United States and Canada In the United States and Canada, as with other styles of hunting, bowhunting is regulated by individual provinces and states. Regulations often address issues such as which area to hunt in, what time of year (season), and which sex and species of game may be taken. In many cases, a special archery season is set aside, to minimize interference from rifle hunters. While bowhunting can run into rifle hunting seasons, hunter orange is typically required to be worn during the cross over seasons. In addition, in an effort to maximize game recovery and shot lethality, there are often technical regulations, such as a minimum draw weight, minimum width of head, and lack of barbs.In general most bow hunting for big game begins in late August or early September in northern states and Canadian provinces, and slightly later in southern states.
Legal and cultural considerations:
New Zealand Organized bow hunting began in New Zealand in 1945. The New Zealand government regulates bowhunting. An annual 3 day field shoot tournament is held every Queen's Birthday Weekend at various locations throughout New Zealand. Bowhunters must have permission to hunt on private land, and they cannot hunt in DOC lands, national parks, or any other reserves without a permit. All native species are protected; only introduced species are legal quarry.
Legal and cultural considerations:
There are no special seasons for bowhunters or for hunting with a firearm. There is an active bow hunters' society.
Legal and cultural considerations:
Australia Bowhunting is practiced in Australia and is not specifically subject to regulation by law. Only non-native species are recognized as game by the Australian Bowhunters Association. However, native species may be killed during government-authorized culls.The states of Victoria and New South Wales both regulate bowhunting. In Victoria hunting is regulated through the Department of Sustainability and Environment (DSE). In New South Wales this is done through the Department of Primary Industry. At the current time there are no specific hunting regulations in other states and territories.In July 2013 the New South Wales Government disbanded the Game Council, and temporarily suspended licensed hunting in NSW State forests.While both Victoria and New South Wales place licensing requirements on would-be bowhunters, the sport is self-regulated. The Australian Bowhunters Association and local clubs assess hunters through the Bowhunter Proficiency Certificate (BPC) which is designed to ensure that animals are killed according to humane principles.
Legal and cultural considerations:
Zimbabwe Zimbabwe has legally permitted hunting with compound bows since 1989 as an exception, and since 1999 under formal legislation. Minimum arrow weights and bow draws are mandated. Bowhunting is only allowed on private or tribal lands, but not in national parks. Bowhunters must be accompanied by licensed guides or professional hunters. Bowhunting of elephants is mostly conducted in Zimbabwe. Following international outrage over the illegal hunt for Cecil, the lion, in 2015 the Parks and Wildlife Management Authority banned all bowhunting unless specifically authorized, as well as other hunting restrictions.
Opposition:
Some are deeply opposed to bow hunting in particular, on the grounds of cruelty. The organization People for the Ethical Treatment of Animals states that "quick kills are rare, and many animals suffer prolonged, painful deaths when hunters severely injure but fail to kill them." Wounding rates A study conducted by the Oklahoma Fish and Wildlife Agencies found that approximately 50% of deer that were shot were never recovered, noting that this rate was similar to data from other studies. Some deer survived for up to 5–7 days before succumbing to their wounds. "71% to 82% of all shots taken" miss the target and "shot placement is, for all practical purposes, random".In another study from Maryland, archers who had passed a pre-season accuracy test claimed that 82% of deer hit were recovered within 24 hours.Danish licensed bowhunters are required to complete a report every time that they kill a roe deer. (To become a licensed bowhunter in Denmark it is necessary to pass a very demanding proficiency test, including a test of accuracy in which five of six arrows must hit within the vital area of game targets ranging from roe deer to pheasant in size at unknown distances up to 25 meters (27 yd). Only 2% of Danish bowhunters use traditional equipment.) For 1999–2004, these reports showed that 576 arrows were released at roe deer. 92.5% of these shots resulted in a dead roe deer being collected by the hunter, and 2.6% are documented as misses. In 5% of reports the deer was hit and wounded (as indicated by bodily fluids on the ground or on the arrow), but not recovered by the hunter. The European Bowhunters Association states that "this percentage compares favorably with other means of harvesting roe deer in Europe." | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**ADP-ribosylhydrolase 1**
ADP-ribosylhydrolase 1:
(ADP-ribosyl)hydrolase 1, also termed [Protein ADP-ribosylarginine] hydrolase and protein-Nω-(ADP-D-ribosyl)-L-arginine ADP-ribosylhydrolase (EC 3.2.2.19), is an enzyme that in humans is encoded by the ADPRH gene. This enzyme is a specific mono(ADP-ribosyl)hydrolase that catalyses the removal of an ADP-ribosyl modification from target arginine residues of protein substrates. The chemical reactions can formally be described as follows: Nω-(ADP-D-ribosyl)-L-arginyl-[protein] + H2O ⇌ ADP-D-ribose + L-arginyl-[protein] In addition, the enzyme can reverse the ADP-ribosylation of free arginine: Nω-(ADP-D-ribosyl)-L-arginine + H2O ⇌ ADP-D-ribose + L-arginine | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Involutory matrix**
Involutory matrix:
In mathematics, an involutory matrix is a square matrix that is its own inverse. That is, multiplication by the matrix A is an involution if and only if A2 = I, where I is the n × n identity matrix. Involutory matrices are all square roots of the identity matrix. This is simply a consequence of the fact that any invertible matrix multiplied by its inverse is the identity.
Examples:
The 2 × 2 real matrix (abc−a) is involutory provided that 1.
Examples:
The Pauli matrices in M(2, C) are involutory: One of the three classes of elementary matrix is involutory, namely the row-interchange elementary matrix. A special case of another class of elementary matrix, that which represents multiplication of a row or column by −1, is also involutory; it is in fact a trivial example of a signature matrix, all of which are involutory.
Examples:
Some simple examples of involutory matrices are shown below.
where I is the 3 × 3 identity matrix (which is trivially involutory); R is the 3 × 3 identity matrix with a pair of interchanged rows; S is a signature matrix.Any block-diagonal matrices constructed from involutory matrices will also be involutory, as a consequence of the linear independence of the blocks.
Symmetry:
An involutory matrix which is also symmetric is an orthogonal matrix, and thus represents an isometry (a linear transformation which preserves Euclidean distance). Conversely every orthogonal involutory matrix is symmetric.
As a special case of this, every reflection and 180° rotation matrix is involutory.
Properties:
An involution is non-defective, and each eigenvalue equals ±1 , so an involution diagonalizes to a signature matrix.
A normal involution is Hermitian (complex) or symmetric (real) and also unitary (complex) or orthogonal (real).
Properties:
The determinant of an involutory matrix over any field is ±1.If A is an n × n matrix, then A is involutory if and only if P+ = (I + A)/2 is idempotent. This relation gives a bijection between involutory matrices and idempotent matrices. Similarly, A is involutory if and only if P− = (I − A)/2 is idempotent. These two operators form the symmetric and antisymmetric projections v±=P±v of a vector v=v++v− with respect to the involution A, in the sense that Av±=±v± , or AP±=±P± . The same construct applies to any involutory function, such as the complex conjugate (real and imaginary parts), transpose (symmetric and antisymmetric matrices), and Hermitian adjoint (Hermitian and skew-Hermitian matrices).
Properties:
If A is an involutory matrix in M(n, R), which is a matrix algebra over the real numbers, and A is not a scalar multiple of I, then the subalgebra {x I + y A: x, y ∈ R} generated by A is isomorphic to the split-complex numbers.
If A and B are two involutory matrices which commute with each other (i.e. AB = BA) then AB is also involutory.
If A is an involutory matrix then every integer power of A is involutory. In fact, An will be equal to A if n is odd and I if n is even. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Pneumatic tool**
Pneumatic tool:
A pneumatic tool, air tool, air-powered tool or pneumatic-powered tool is a type of power tool, driven by compressed air supplied by an air compressor. Pneumatic tools can also be driven by compressed carbon dioxide (CO2) stored in small cylinders allowing for portability.Most pneumatic tools convert the compressed air to work using a pneumatic motor. Compared to electric power tool equivalents, pneumatic tools are safer to run and maintain, without risk of sparks, short-circuiting or electrocution, and have a higher power to weight ratio, allowing a smaller, lighter tool to accomplish the same task. Furthermore, they are less likely to self-destruct in case the tool is jammed or overloaded.General grade pneumatic tools with a short life span are commonly less expensive and considered “disposable tools” in tooling industries, while industrial grade pneumatic tools with long life span are more expensive. In general, pneumatic tools are cheaper than the equivalent electric-powered tools. Regular lubrication of the tools is still needed however.Most pneumatic tools are to be supplied with compressed air at 4 to 6 bar.
Advantages and disadvantages:
Pneumatic tools have many benefits which have contributed to their rise in popularity. The benefits of using compressed air to power tools are: Inexpensive Safe to use Easy to operate Portable Low theft ratesThe primary disadvantage of pneumatic tools is the need for an air compressor, which can be expensive. Pneumatic tools also need to be properly maintained and oiled regularly. Failing to maintain tools can lead to deterioration, due to a build up residual oil and water.
Technical terms:
Pneumatic tools are rated using several metrics: Free Speed (rpm), Air Pressure (psi/bar), Air Consumption (cfm/scfm or m3/min), Horse Power (hp), and spindle size. Each individual tool has its own specific requirements which determine their compatibility with air compressor systems.
Technical terms:
Flow or airflow, related to air consumption in pneumatic tools, represents the quantity of compressed air that passes through a section over a unit of time. It is represented in l/min, m3, at the equivalent value in free air in conditions of standard reference atmosphere (SRA). For example: +20 c, 65% of relative humidity, 1013 mbar, in accordance with norms NFE.
Types of pneumatic tools:
Pneumatic tools come in many shapes and form, including small and large-sized hand tools.
The most common types of pneumatic tools include: | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Protein xylosyltransferase**
Protein xylosyltransferase:
In enzymology, a protein xylosyltransferase (EC 2.4.2.26) is an enzyme that catalyzes the chemical reaction in which a beta-D-xylosyl residue is transferred from UDP-D-xylose to the sidechain oxygen atom of a serine residue in a protein.
Protein xylosyltransferase:
This enzyme belongs to the family of glycosyltransferases, specifically the pentosyltransferases. The systematic name of this enzyme class is UDP-D-xylose:protein beta-D-xylosyltransferase. Other names in common use include UDP-D-xylose:core protein beta-D-xylosyltransferase, UDP-D-xylose:core protein xylosyltransferase, UDP-D-xylose:proteoglycan core protein beta-D-xylosyltransferase, UDP-xylose-core protein beta-D-xylosyltransferase, uridine diphosphoxylose-core protein beta-xylosyltransferase, and uridine diphosphoxylose-protein xylosyltransferase. This enzyme participates in the biosynthesis of chondroitin sulfate and glycan structures. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Methylenedioxybenzylpiperazine**
Methylenedioxybenzylpiperazine:
1-(3,4-Methylenedioxybenzyl)piperazine (MDBZP, piperonylpiperazine) is a chemical compound of the piperazine chemical class related to benzylpiperazine (BZP). MDBZP has been sold as a designer drug and has even been found as an ingredient in street Ecstasy pills. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**YME1L1**
YME1L1:
ATP-dependent metalloprotease YME1L1 is an enzyme that in humans is encoded by the YME1L1 gene. YME1L1 belongs to the AAA family of ATPases and mainly functions in the maintenance of mitochondrial morphology. Mutations in this gene would cause infantile-onset mitochondriopathy.
Structure:
Gene The YME1L1 gene is located at chromosome 10p14, consisting of 20 exons. Two transcript variants encoding different isoforms have been found for this gene.
Protein YME1L1 consists of 716 amino acids and is highly similar to all mitochondrial AAA proteases and in particular to yeast Yme1p. Three different domains are identified via sequence analysis, including an AAA consensus sequence between amino acids 317 and 502, an ATP/GTP binding motif, and a HEXXH motif typical of a zinc-dependent binding domain.
Function:
YME1L1 is embedded in the inner mitochondrial membrane and is more abundant in tissues with a high content of mitochondria such as human adult heart, skeletal muscle, and pancreas RNA. YME1L1 is a member of the AAA family of ATPases and has an important role for the maintenance of mitochondrial morphology. Its mature form assembles into a homo-oligomeric complex within the inner mitochondrial membrane (IM). It degrades both intermembrane space and IM proteins, including lipid transfer proteins, components of protein translocases of the IM, and the dynamin-like GTPase optic atrophy 1 (OPA1) Loss of YME1L1 accelerates OMA1-dependent long-form OPA1 cleavage, resulting in short-form OPA1 accumulation, increased mitochondrial fission, and mitochondrial network fragmentation. It's also reported that YME1L1 controls the accumulation of respiratory chain subunits and is required for apoptotic resistance, cristae morphogenesis, and cell proliferation.
Clinical significance:
A homozygous mutation in the YME1L1 gene would cause infantile-onset mitochondriopathy, with severe intellectual disability, muscular impairments, and optic nerve atrophy. The missense mutation affects the MPP processing site and impairs YME1L1 maturation, leading to its rapid degradation, and also leads to a proliferation defect, abnormal OPA1 processing and mitochondrial fragmentation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Actinic cheilitis**
Actinic cheilitis:
Actinic cheilitis is cheilitis (lip inflammation) caused by long term sunlight exposure. Essentially it is a burn, and a variant of actinic keratosis which occurs on the lip. It is a premalignant condition, as it can develop into squamous cell carcinoma (a type of mouth cancer).
Signs and symptoms:
AC almost always affects the lower lip and only rarely the upper lip, probably because the lower lip is more exposed to the sun. In the unusual cases reported where it affects the upper lip, this may be due to upper lip prominence. The commissures (corners of the mouth) are not usually involved.Affected individuals may experience symptoms such as a dry sensation and cracking of the lips.
Signs and symptoms:
It is usually painless and persistent.
Signs and symptoms:
The appearance is variable. White lesions indicate hyperkeratosis. Red, erosive or ulcerative lesions indicate atrophy, loss of epithelium and inflammation. Early, acute lesions may be erythematous (red) and edematous (swollen). With months and years of sun exposure, the lesion becomes chronic and may be grey-white in color and appear dry, scaly and wrinkled.There is thickening whitish discoloration of the lip at the border of the lip and skin. There is also a loss of the usually sharp border between the red of the lip and the normal skin, known as the vermillion border. The lip may become scaly and indurated as AC progresses.
Signs and symptoms:
When palpated, the lip may have a texture similar to rubbing the gloved finger along sandpaper.AC may occur with skin lesions of actinic keratosis or skin cancer elsewhere, particularly on the head and neck since these are the most sun exposed areas. Rarely it may represent a genetic susceptibility to light damage (e.g. xeroderma pigmentosum or actinic prurigo).
Causes:
AC is caused by chronic and excessive exposure to ultraviolet radiation in sunlight.
Risk factors include: Outdoor lifestyle: e.g. farmers, sailors, fishermen, windsurfers, mountaineers, golfers, etc. This has given rise to synonyms for this condition such as "sailor's lip" and "farmer's lip". The prevalence in agricultural workers in a semi-arid region of Brazil is reported to be 16.7%.
Light skin complexion: the condition typically affects individuals with lighter skin tones, particularly Caucasians living in tropical regions. In one report, 96% of persons with AC had phenotype II according to the Fitzpatrick scale.
Age: AC typically affects older individuals, and rarely those under the age of 45.
Gender: the condition affects males more commonly than females. Sometimes this ratio is reported as high as 10:1.Additional factors may also play a role, including tobacco use, lip irritation, poor oral hygiene, and ill-fitting dentures.
Prevention:
To prevent AC from developing, protective measures could be undertaken such as avoiding mid-day sun, or use of a broad-brimmed hat, lip balm with anti UVA and UVB ingredients (e.g. para-aminobenzoic acid), or sun blocking agents (e.g. zinc oxide, titanium oxide) prior to sun exposure.
Treatment:
This condition is considered premalignant because it may lead to squamous cell carcinoma in about 10% of all cases. It is not possible to predict which cases will progress into SCC, so the current consensus is that all lesions should be treated.Treatment options include 5-fluorouracil, imiquimod, scalpel vermillionectomy, chemical peel, electrosurgery, and carbon dioxide laser vaporization. These curative treatments attempt to destroy or remove the damaged epithelium. All methods are associated with some degree of pain, edema, and a relatively low rate of recurrence.
Treatment:
Medication Topical 5-fluorouracil (5-FU, Efudex, Carac) has been shown to be an effective therapy for diffuse, but minor actinic cheilitis. 5-fluorouracil works by blocking DNA synthesis. Cells that are rapidly growing need more DNA, so they accumulate more 5-fluorouracil, resulting in their death. Normal skin is much less affected. The treatment usually takes 2–4 weeks depending on the response. The typical response includes an inflammatory phase, followed by redness, burning, oozing, and finally erosion. Treatment is stopped when ulceration and crusting appear. There is minimal scarring. Complete clearance has been reported in about 50% of patients.Imiquimod (Aldara) is an immune response modifier that has been studied for the treatment of actinic cheilitis. It promotes an immune response in the skin leading to apoptosis (death) of the tumor cells. It causes the epidermis to be invaded by macrophages, which leads to epidermal erosion. T-cells are also activated as a result of imiquimod treatment. Imiquimod appears to promote an "immune memory" that reduces the recurrence of lesions. There is minimal scarring. Complete clearance has been demonstrated in up to 45% of patients with actinic keratoses. However, the dose and duration of therapy, as well as the long-term efficacy, still need to be established in the treatment of actinic cheilitis.
Treatment:
Procedures Both cryosurgery and electrosurgery are effective choices for small areas of actinic cheilitis. Cryosurgery is accomplished by applying liquid nitrogen in an open spraying technique. Local anesthesia is not required, but treatment of the entire lip can be quite painful. Cure rates in excess of 96% have been reported. Cryosurgery is the treatment of choice for focal areas of actinic cheilitis. Electrosurgery is an alternate treatment, but local anesthesia is required, making it less practical than cryosurgery. With both techniques, adjacent tissue damage can delay healing and promote scar formation.More extensive or recurring areas of actinic cheilitis may be treated with either a shave vermillionectomy or a carbon dioxide laser. The shave vemillionectomy removes a portion of the vermillion border but leaves the underlying muscle intact. Considerable bleeding can occur during the procedure due to the vascular nature of the lip. A linear scar may also form after treatment, but this can usually be minimized with massage and steroids. Healing time is short, and effectiveness is very high.A newer procedure uses a carbon dioxide laser to ablate the vermillion border. This treatment is relatively quick and easy to perform, but it requires a skilled operator. Anesthesia is usually required. Secondary infection and scarring can occur with laser ablation. In most cases, the scar is minimal, and responds well to steroids. Pain can be a progressive problem during the healing phase, which can last three weeks or more. However, the carbon dioxide laser also offers a very high success rate, with very few recurrences.Chemical peeling with 50% trichloroacetic acid has also been evaluated, but results have been poor. Healing usually takes 7–10 days with very few side effects. However, limited studies show that the success rate may be lower than 30%. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Hereditary carrier**
Hereditary carrier:
A hereditary carrier (genetic carrier or just carrier), is a person or other organism that has inherited a recessive allele for a genetic trait or mutation but usually does not display that trait or show symptoms of the disease. Carriers are, however, able to pass the allele onto their offspring, who may then express the genetic trait.
Carriers in autosomal inheritances:
Autosomal dominant-recessive inheritance is made possible by the fact that the individuals of most species (including all higher animals and plants) have two alleles of most hereditary predispositions because the chromosomes in the cell nucleus are usually present in pairs (diploid). Carriers can be female or male as the autosomes are homologous independently from the sex.
Carriers in autosomal inheritances:
In carriers the expression of a certain characteristic is recessive. The individual has both a genetic predisposition for the dominant trait and a genetic predisposition for the recessive trait, and the dominant expression prevails in the phenotype. In an individual which is heterozygous regarding a certain allele, it is not externally recognisable that it also has the recessive allele. But if the carrier has a child, the recessive trait appears in the phenotype, in case the descendant receives the recessive allele from both parents and therefore does not possess the dominant allele that would cover the recessive trait. According to Mendelian Law of Segregation of genes an average of 25% of the offspring become homozygous and express the recessive trait. Carriers can either pass on normal autosomal recessive hereditary traits or an autosomal recessive hereditary disease.
Carriers in gonosomal inheritances:
Gonosomal recessive genes are also passed on by carriers. The term is used in human genetics in cases of hereditary traits in which the observed trait lies on the female sex chromosome, the X chromosome. The carriers are always women. Men cannot be carriers because they only have one X chromosome. The Y chromosome is not a really homologous chromosome. For this reason, the genetic make-up of the observed trait is not twofold. If a man has a certain recessive genetic disposition on his X chromosome, this is called hemizygous and it gets phenotypically expressed. Also a recessive genetic disposition on his Y chromosome - also hemizygous - can come to expression, because there is no homologous chromosome with an allele, which could overlay it. If there is no genetic information on the Y chromosome for a certain trait, the effect of the Y is neutral and the allele on his X chromosome, which would be recessive in a heterozygous woman, can now alone come to expression.
Carriers in gonosomal inheritances:
Women have two homologous sex chromosomes (XX). Therefore, women can be carriers of X-linked genes. Examples of traits inherited via the X chromosome are color blindness and the most common hereditary form of Haemophilia. Men are affected much more often than women.
Carriers in gonosomal inheritances:
Queen Victoria, and her daughters Princesses Alice and Beatrix, were carriers of the hemophilia gene (an abnormal allele of a gene, necessary to produce one of the blood clotting factors). Both had children who continued to pass on the gene to succeeding generations of the royal houses of Spain and Russia, into which they married. Since males only have one X chromosome, males who carried the altered gene had hemophilia B. Females have two X chromosomes, so one copy of an X-linked recessive gene would cause them to be an asymptomatic carrier. These females simply passed it to half of their children.Gonosomal dominant inheritances are also known. There are no carriers since owners of a dominant hereditary disposition phenotypically express the trait in each case. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Immunologic adjuvant**
Immunologic adjuvant:
In immunology, an adjuvant is a substance that increases or modulates the immune response to a vaccine. The word "adjuvant" comes from the Latin word adiuvare, meaning to help or aid. "An immunologic adjuvant is defined as any substance that acts to accelerate, prolong, or enhance antigen-specific immune responses when used in combination with specific vaccine antigens."In the early days of vaccine manufacture, significant variations in the efficacy of different batches of the same vaccine were correctly assumed to be caused by contamination of the reaction vessels. However, it was soon found that more scrupulous cleaning actually seemed to reduce the effectiveness of the vaccines, and some contaminants actually enhanced the immune response.
Immunologic adjuvant:
There are many known adjuvants in widespread use, including aluminium salts, oils and virosomes.
Overview:
Adjuvants in immunology are often used to modify or augment the effects of a vaccine by stimulating the immune system to respond to the vaccine more vigorously, and thus providing increased immunity to a particular disease. Adjuvants accomplish this task by mimicking specific sets of evolutionarily conserved molecules, so called pathogen-associated molecular patterns, which include liposomes, lipopolysaccharide, molecular cages for antigens, components of bacterial cell walls, and endocytosed nucleic acids such as RNA, double-stranded RNA, single-stranded DNA, and unmethylated CpG dinucleotide-containing DNA. Because immune systems have evolved to recognize these specific antigenic moieties, the presence of an adjuvant in conjunction with the vaccine can greatly increase the innate immune response to the antigen by augmenting the activities of dendritic cells, lymphocytes, and macrophages by mimicking a natural infection.
Overview:
Types Inorganic compounds: potassium alum, aluminium hydroxide, aluminium phosphate, calcium phosphate hydroxide Oils: paraffin oil, propolis (only in preclinical studies), Adjuvant 65 (based on peanut oil. Adjuvant 65 was tested in influenza vaccines in the 1970s, but was never released commercially.) Bacterial products: killed bacteria of the species Bordetella pertussis, Mycobacterium bovis, toxoids Plant saponins from Quillaja (see Quil A), soybean, Polygala senega Cytokines: IL-1, IL-2, IL-12 Combinations: Freund's complete adjuvant, Freund's incomplete adjuvant Other organic substances: squalene Inorganic adjuvants Aluminium salts There are many adjuvants, some of which are inorganic, that carry the potential to augment immunogenicity. Alum was the first aluminium salt used for this purpose, but has been almost completely replaced by aluminium hydroxide and aluminium phosphate for commercial vaccines. Aluminium salts are the most commonly-used adjuvants in human vaccines. Their adjuvant activity was described in 1926.The precise mechanism of aluminium salts remains unclear but some insights have been gained. It was formerly thought that they function as delivery systems by generating depots that trap antigens at the injection site, providing a slow release that continues to stimulate the immune system. However, studies have shown that surgical removal of these depots had no impact on the magnitude of IgG1 response.Alum can trigger dendritic cells and other immune cells to secrete Interleukin 1 beta (IL‑1β), an immune signal that promotes antibody production. Alum adheres to the cell's plasma membrane and rearranges certain lipids there. Spurred into action, the dendritic cells pick up the antigen and speed to lymph nodes, where they stick tightly to a helper T cell and presumably induce an immune response. A second mechanism depends on alum killing immune cells at the injection site although researchers aren't sure exactly how alum kills these cells. It has been speculated that the dying cells release DNA which serves as an immune alarm. Some studies found that DNA from dying cells causes them to adhere more tightly to helper T cells which ultimately leads to an increased release of antibodies by B cells. No matter what the mechanism is, alum is not a perfect adjuvant because it does not work with all antigens (e.g. malaria and tuberculosis). However, recent research indicates that alum formulated in a nanoparticle form rather than microparticles can broaden the utility of alum adjuvants and promote stronger adjuvant effects.
Overview:
Organic adjuvants Freund's complete adjuvant is a solution of inactivated Mycobacterium tuberculosis in mineral oil developed in 1930. It is not safe enough for human use. A version without the bacteria, that is only oil in water, is known as Freund's incomplete adjuvant. It helps vaccines release antigens for a longer time. Despite the side effects, its potential benefit has led to a few clinical trials.Squalene is a naturally-occurring organic compound used in human and animal vaccines. Squalene is an oil, made up of carbon and hydrogen atoms, produced by plants and is present in many foods. Squalene is also produced by the human liver as a precursor to cholesterol and is present in human sebum. MF59 is an oil-in-water emulsion of squalene adjuvant used in some human vaccines. As of 2021, over 22 million doses of one vaccine with squalene, FLUAD, have been administered with no severe adverse effects reported. AS03 is another squalene-containing adjuvant.The plant extract QS-21 is a liposome made up of plant saponins from Quillaja saponaria, the soap bark tree. It is a part of the Shingrix vaccine approved in 2017.Monophosphoryl lipid A (MPL), a detoxified version of Salmonella minnesota lipopolysaccharide, interacts with the receptor TLR4 to enhance immune response. It is also a part of the Shingrix vaccine.
Adaptive immune response:
In order to understand the links between the innate immune response and the adaptive immune response to help substantiate an adjuvant function in enhancing adaptive immune responses to the specific antigen of a vaccine, the following points should be considered: Innate immune response cells such as dendritic cells engulf pathogens through a process called phagocytosis.
Dendritic cells then migrate to the lymph nodes where T cells (adaptive immune cells) wait for signals to trigger their activation.
In the lymph nodes, dendritic cells mince the engulfed pathogen and then express the pathogen clippings as antigen on their cell surface by coupling them to a special receptor known as a major histocompatibility complex.
T cells can then recognize these clippings and undergo a cellular transformation resulting in their own activation.
γδ T cells possess characteristics of both the innate and adaptive immune responses.
Macrophages can also activate T cells in a similar approach (but do not do so naturally).This process carried out by both dendritic cells and macrophages is termed antigen presentation and represents a physical link between the innate and adaptive immune responses.
Adaptive immune response:
Upon activation, mast cells release heparin and histamine to effectively increase trafficking to and seal off the site of infection to allow immune cells of both systems to clear the area of pathogens. In addition, mast cells also release chemokines which result in the positive chemotaxis of other immune cells of both the innate and adaptive immune responses to the infected area.Due to the variety of mechanisms and links between the innate and adaptive immune response, an adjuvant-enhanced innate immune response results in an enhanced adaptive immune response. Specifically, adjuvants may exert their immune-enhancing effects according to five immune-functional activities.
Adaptive immune response:
First, adjuvants may help in the translocation of antigens to the lymph nodes where they can be recognized by T cells. This will ultimately lead to greater T cell activity resulting in a heightened clearance of pathogen throughout the organism.
Adaptive immune response:
Second, adjuvants may provide physical protection to antigens which grants the antigen a prolonged delivery. This means the organism will be exposed to the antigen for a longer duration, making the immune system more robust as it makes use of the additional time by upregulating the production of B and T cells needed for greater immunological memory in the adaptive immune response.
Adaptive immune response:
Third, adjuvants may help to increase the capacity to cause local reactions at the injection site (during vaccination), inducing greater release of danger signals by chemokine releasing cells such as helper T cells and mast cells.
Fourth, they may induce the release of inflammatory cytokines which helps to not only recruit B and T cells at sites of infection but also to increase transcriptional events leading to a net increase of immune cells as a whole.
Finally, adjuvants are believed to increase the innate immune response to antigen by interacting with pattern recognition receptors (PRRs) on or within accessory cells.
Toll-like receptors:
The ability of the immune system to recognize molecules that are broadly shared by pathogens is, in part, due to the presence of immune receptors called toll-like receptors (TLRs) that are expressed on the membranes of leukocytes including dendritic cells, macrophages, natural killer cells, cells of the adaptive immunity (T and B lymphocytes) and non-immune cells (epithelial and endothelial cells, and fibroblasts).The binding of ligands – either in the form of adjuvant used in vaccinations or in the form of invasive moieties during times of natural infection – TLR marks the key molecular events that ultimately lead to innate immune responses and the development of antigen-specific acquired immunity.As of 2016, several TLR ligands were in clinical development or being tested in animal models as potential adjuvants.
Medical complications:
Humans Aluminium salts used in many human vaccines are regarded as safe by Food and Drug Administration. Although there are studies suggesting the role of aluminium, especially injected highly bioavailable antigen-aluminium complexes when used as adjuvant, in Alzheimer's disease development, the majority of researchers do not support a causal connection with aluminium. Adjuvants may make vaccines too reactogenic, which often leads to fever. This is often an expected outcome upon vaccination and is usually controlled in infants by over-the-counter medication if necessary.
Medical complications:
An increased number of narcolepsy (a chronic sleep disorder) cases in children and adolescents was observed in Scandinavian and other European countries after vaccinations to address the H1N1 “swine flu” pandemic in 2009. Narcolepsy has previously been associated with HLA-subtype DQB1*602, which has led to the prediction that it is an autoimmune process. After a series of epidemiological investigations, researchers found that the higher incidence correlated with the use of AS03-adjuvanted influenza vaccine (Pandemrix). Those vaccinated with Pandemrix have almost a twelve-times higher risk of developing the disease. The adjuvant of the vaccine contained vitamin E that was no more than a day's normal dietary intake. Vitamin E increases hypocretin-specific fragments that bind to DQB1*602 in cell culture experiments, leading to the hypothesis that autoimmunity may arise in genetically susceptible individuals, but there is no clinical data to support this hypothesis. The third AS03 ingredient is polysorbate 80. Polysorbate 80 is also found in both the Oxford–AstraZeneca and Janssen COVID-19 vaccines.
Medical complications:
Animals Aluminium adjuvants have caused motor neuron death in mice when injected directly onto the spine at the scruff of the neck, and oil–water suspensions have been reported to increase the risk of autoimmune disease in mice. Squalene has caused rheumatoid arthritis in rats already prone to arthritis.In cats, vaccine-associated sarcoma (VAS) occurs at a rate of 1–10 per ten thousand injections. In 1993, a causal relationship between VAS and administration of aluminium adjuvated rabies and FeLV vaccines was established through epidemiologic methods, and in 1996 the Vaccine-Associated Feline Sarcoma Task Force was formed to address the problem. However, evidence conflicts on whether types of vaccines, manufacturers or factors have been associated with sarcomas.
Controversy:
TLR signaling As of 2006, the premise that TLR signaling acts as the key node in antigen-mediated inflammatory responses has been in question as researchers have observed antigen-mediated inflammatory responses in leukocytes in the absence of TLR signaling. One researcher found that in the absence of MyD88 and Trif (essential adapter proteins in TLR signaling), they were still able to induce inflammatory responses, increase T cell activation and generate greater B cell abundancy using conventional adjuvants (alum, Freund's complete adjuvant, Freund's incomplete adjuvant, and monophosphoryl-lipid A/trehalose dicorynomycolate (Ribi's adjuvant)).These observations suggest that although TLR activation can lead to increases in antibody responses, TLR activation is not required to induce enhanced innate and adaptive responses to antigens.
Controversy:
Investigating the mechanisms which underlie TLR signaling has been significant in understanding why adjuvants used during vaccinations are so important in augmenting adaptive immune responses to specific antigens. However, with the knowledge that TLR activation is not required for the immune-enhancing effects caused by common adjuvants, we can conclude that there are, in all likelihood, other receptors besides TLRs that have not yet been characterized, opening the door to future research.
Controversy:
Safety Reports after the first Gulf War linked anthrax vaccine adjuvants to Gulf War syndrome in American and British troops. The United States Department of Defense strongly denied the claims.
Controversy:
Discussing the safety of squalene as an adjuvant in 2006, the World Health Organisation stated "follow-up to detect any vaccine-related adverse events will need to be performed." No such followup has been published by the WHO. Subsequently, the American National Center for Biotechnology Information published an article discussing the comparative safety of vaccine adjuvants which stated that "the biggest remaining challenge in the adjuvant field is to decipher the potential relationship between adjuvants and rare vaccine adverse reactions, such as narcolepsy, macrophagic myofasciitis or Alzheimer's disease." | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Conductor-discriminant formula**
Conductor-discriminant formula:
In mathematics, the conductor-discriminant formula or Führerdiskriminantenproduktformel, introduced by Hasse (1926, 1930) for abelian extensions and by Artin (1931) for Galois extensions, is a formula calculating the relative discriminant of a finite Galois extension L/K of local or global fields from the Artin conductors of the irreducible characters Irr(G) of the Galois group G=G(L/K)
Statement:
Let L/K be a finite Galois extension of global fields with Galois group G . Then the discriminant equals dL/K=∏χ∈Irr(G)f(χ)χ(1), where f(χ) equals the global Artin conductor of χ
Example:
Let L=Q(ζpn)/Q be a cyclotomic extension of the rationals. The Galois group G equals (Z/pn)× . Because (p) is the only finite prime ramified, the global Artin conductor f(χ) equals the local one f(p)(χ) . Because G is abelian, every non-trivial irreducible character χ is of degree 1=χ(1) . Then, the local Artin conductor of χ equals the conductor of the p -adic completion of Lχ=Lker(χ)/Q , i.e. (p)np , where np is the smallest natural number such that UQp(np)⊆NLpχ/Qp(ULpχ) . If p>2 , the Galois group G(Lp/Qp)=G(L/Qp)=(Z/pn)× is cyclic of order φ(pn) , and by local class field theory and using that UQp/UQp(k)=(Z/pk)× one sees easily that if χ factors through a primitive character of (Z/pi)× , then f(p)(χ)=pi whence as there are φ(pi)−φ(pi−1) primitive characters of (Z/pi)× we obtain from the formula dL/Q=(pφ(pn)(n−1/(p−1))) , the exponent is ∑i=0n(φ(pi)−φ(pi−1))i=nφ(pn)−1−(p−1)∑i=0n−2pi=nφ(pn)−pn−1. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Combination machine**
Combination machine:
A combination machine is a woodworking machine that combines the functions of two or more separate machines into a single unit. For example, a combination machine might consist of a tablesaw with a side-mounted jointer. Another common example of this type of machine is the jointer-thicknesser (also known as an over-under) which combines the function of a jointer with that of a planer.
Design:
Some combination machines run all of their functions from a single motor; others may use more than one. Cutter heads are often shared: for example a jointer-thicknesser may use the same cutter head for both functions. The machines rely upon well thought-out designs which allow the user to switch from one function to another easily.
Advantages:
One rationale for the production of these machines is space saving. A combination machine takes up much less space than the equivalent separate machines. Most European machines have a sliding table that tends to make them safer than typical North American table saws. Even though top end combination machines can be quite expensive, there usually is a cost saving over separate machines of similar quality.
Disadvantages:
There are some trade offs with combination machines. Set up time is increased when moving from one function to another and back. In some cases, machine settings are lost during the change over and have to be re-established when changing back. In some lower end machines, there may be compromises in design which limit the function or robustness of the machine. Finally, they represent a single point of failure in that a mechanical problem with the machine will generally mean that none of the machine's functions are available. These disadvantages are offset by the small size of the machine footprint and potential cost saving and so they are very popular with hobbyists and workshops in which space is limited.
The Shopsmith:
The Shopsmith is a lathe-based multi-tool that uses a single motor to perform lathe, tablesaw, sanding, and drill press functions. Variations include horizontal boring and disc sander. The original Shopsmith 10E and 10ER were invented by Dr. Hans Goldschmidt of Albany, CA, in 1947; made by the Magna America Corporation in Berkeley, CA, from 1947 to 1953; and sold by Montgomery Ward. The Mark 5 debuted in 1953 but went out of production in 1964. The earliest 10E/10ER Shopsmith machines could be accompanied by optional add-ons such as a jointer, a jig saw, as well as smaller accessories allowing use as a shaper. A bandsaw was introduced in 1957 for the Mark series of machines. Magna also made the Sawsmith radial arm saw, the Mark 2 (1958-60) and the short-lived Mark VII, all compatible with the Mark V accessories. The Shopsmith Mark V was resurrected by Shopsmith Inc. in 1972 in Dayton, OH, by John Folkerth, founder and first chairman of the company. As of 2014 the machines were manufactured by RLF Brands, successor to Shopsmith Inc..
The Shopsmith:
RLF Brands continues to manufacture and market a variety of add-on tools that can be run by the headstock. These tools include a bandsaw (little changed from the original 1957 version), wood shaper, jointer, belt sander, strip sander, scroll saw and thickness planer. Changes from one function to the other is usually less than 90 seconds.
The Shopsmith:
One of the unique features of the Shopsmith is its method of speed control. Rather than multiple pairs of pulleys or an electronic speed control, the Mark V uses a Reeves-type continuously variable transmission consisting of two variable diameter pulleys controlled by a dial and worm gear. (Standard on the Mark V, this system was optionally available on the early 10ER machines.) Not only does this give theoretically infinite speed variation between the maximum and minimum speeds, it is also simple enough to be serviced fairly easily by a hobbyist. The new (as of 2010) Shopsmith Mark 7 uses a computer-controlled motor that offers more power, greater speed range, reversibility and easy conversion to 220 V.
The Shopsmith:
An injury suffered by the user of a Shopsmith gave the Supreme Court of California the opportunity to create the modern rule of strict liability for defective products in 1963.
European Combination Machine:
Several companies in Austria, Italy, France and Belgium manufacture what is commonly known in North America as a Euro(pean) combination machine, which typically contains a sliding-table saw with a scoring blade, a shaper, a thicknesser, a jointer, and a mortiser. These machines generally have 3 motors, one for the table saw, one for the shaper, and one shared by the thickness planer/jointer and mortiser. European combination machines are geared for the serious hobbyist or professional woodworker or cabinet maker. They are constructed of cast iron and heavy gauge steel, weigh from 1000 to 2000 lbs., and range in price from around $5,000 to over $30,000 (2010, U.S. dollars). Manufacturers include Felder (Felder and Hammer brands), Kitty, Knapp, Lurem, Mini-Max, Robland, Rojek, Veba and others. Rojek and Robland manufacture entry level models, Hammer, Lurem, MiniMax and Veba mid-range models, Felder and Knapp high-end models. Robland purchased Knapp from the Metabo group in 2000.
European Combination Machine:
The European combination machine allows efficient processing of both rough-cut timber and sheet stock (i.e. plywood). The sliding table can work in conjunction with either the table saw or the shaper. Outfitted with an 8-foot sliding table and outrigger, a single person can cut 4'x8' plywood very accurately and efficiently. Changing between most functions takes only a few seconds. The sliding table allows a straight edge to be cut on rough lumber, without the use of a fence. It also allows a cut to be made accurately at any angle across a sheet of plywood in just seconds - something that cannot be done nearly as easily, if at all, on a table saw. Used in conjunction with the shaper, the sliding table allows molding, door panels, rails and stiles, to be milled quickly and more accurately than a stand-alone shaper. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cohl Furey**
Cohl Furey:
Cohl Furey, also known as Nichol Furey, is a Canadian mathematical physicist.
Career:
Furey has a bachelor's degree in mathematics and physics from Simon Fraser University (2005), Master's degree from the University of Cambridge (2006) and a Ph.D in theoretical physics from the University of Waterloo (2015). She was a research fellow at the University of Cambridge from 2016 to 2019 and spent a few months at the African Institute for Mathematical Sciences in Cape Town. Since 2020, she has been at the Humboldt University of Berlin on a Freigeist-Fellowship by the Volkswagen Foundation.Her main interests are division algebras, Clifford algebras, and Jordan algebras, and their relation to particle physics. Her work focuses on finding an underlying mathematical structure to the Standard Model of particle physics. She is most noted for her work on octonions.She has worked on attempting to obtain the Standard Model of particle physics from octonionic constructions. In her 2018 paper "SU(3)C × SU(2)L × U(1)Y ( × U(1)X ) as a symmetry of division algebraic ladder operators," according to Quanta Magazine, "she consolidated several findings to construct the full Standard Model symmetry group, SU(3) × SU(2) × U(1), for a single generation of particles, with the math producing the correct array of electric charges and other attributes for an electron, neutrino, three up quarks, three down quarks and their anti-particles. The math also suggests a reason why electric charge is quantized in discrete units — essentially, because whole numbers are." In 2022 together with Mia Hughes, she linked the symmetry breaking in physics to division algebras including octonions.
Media recognition:
In 2019, Wired.com listed her in their article "10 Women in Science and Tech Who Should Be Household Names".
Notable publications:
Furey, Nichol; Hughes, Mia J. (2022-08-10). "Division algebraic symmetry breaking". Physics Letters B. 831: 137186. doi:10.1016/j.physletb.2022.137186. ISSN 0370-2693.
Notable publications:
C. Furey, "Three generations, two unbroken gauge symmetries, and one eight-dimensional algebra", Phys. Lett. B, 785 (2018) p. 84-89 (See addendum, arXiv version C. Furey, "SU(3)C x SU(2)L x U(1)Y ( x U(1)X ) as a symmetry of division algebraic ladder operators", Eur. Phys. J. C, 78 5 (2018) 375 C. Furey, "A demonstration that electroweak theory could violate parity automatically (leptonic case)", Int.J.Mod.Phys.A, (2018) C. Furey, "Standard model physics from an algebra?", PhD thesis, University of Waterloo, [arXiv:1611.09182] C. Furey, "Charge quantization from a number operator", Phys. Lett. B, 742 (2015), pp. 195–199 C. Furey, "Generations: Three prints, in colour", JHEP 10 (2014) 046 [arXiv:1405.4601 hep-th] C. Furey, "Towards a unified theory of ideals", Phys. Rev. D 86 (2012) 025024, [arXiv:1002.1497 hep-th] Furey, DeBenedictis, "Wormhole throats in Rm gravity", Class. Quantum Grav. 22 (2005) 313–322, [arXiv:gr-qc/0410088] | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**1070 aluminium alloy**
1070 aluminium alloy:
1070 is a pure aluminium alloy. It is a wrought alloy with a high corrosion resistance and an excellent brazing ability. 1070 Aluminium alloy has aluminium, iron, silicon, zinc, vanadium, copper, titanium, magnesium, and manganese as minor elements.
Applications:
Aluminium 1070 alloy is used in the following areas: General industrial components Building and construction Transport Electrical material PS plates Strips for ornaments Communication cables Refrigerator and freezer cabinets | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**TextGrid**
TextGrid:
TextGrid is a research group with the goal of supporting access to and the exchange of information in the humanities and social sciences with the help of modern information technology (the grid).
The project is funded by the Federal Ministry of Education and Research (Germany). TextGrid is one project within the D-Grid initiative and part of WissGrid.
Project phases:
The TextGrid project started in February 2006. During the first phase of the project the development of the software begun. In consequence an infrastructure for the virtual research environment was built. During the second project phase (June 2009 to May 2012) a productive version of the software was created and the user base was broadened. Meanwhile, the project reached its third funding phase (June 2012 to May 2015) entitled "TextGrid - Virtual Research Environment for the Humanities". The objective within this phase is the transformation of the project for the continuous operation in financial, legal and technical terms.The following partner institutions are participating during the third funding phase of TextGrid: Berlin-Brandenburg Academy of Sciences and Humanities, Berlin DAASI International GmbH, Tübingen University of Applied Sciences Worms, Faculty of Computer Sciences University of Göttingen, Göttingen State and University Library (project management) Gesellschaft für wissenschaftliche Datenverarbeitung mbH Göttingen Institut für Deutsche Sprache, Mannheim University of Würzburg Max Planck Institute for the History of Science, Berlin Berlin Institute of Technology Technische Universität Darmstadt, Department for Literary Studies
Software:
Scholars from humanities and cultural studies can do their research on textbased data jointly or alone by using the TextGrid software. This environment consists of two main components: The TextGrid Repository is long-term storage of subject specific contents where digital research data can be stored. This is to guarantee the long-term availability and access to data and also to provide cooperation for the scholars.
Software:
The TextGrid Laboratory is the client software of the virtual research environment and combines diverse services and tools within the interface that can be used intuitively. The TextGridLab can be extended and therefore be used by scholars from diverse fields of research and interest. The software is available for all prevalent operation systems.
Further services:
User of TextGrid are able to contact the developers of the software and further involved persons. For this purpose there are different open mailing-lists available. Furthermore, user meetings are arranged on a regular basis and training courses and workshops are offered.
User projects:
Meanwhile, a number of user cases and edition projects which are working with TextGrid are established. More information on these projects and their experiences with TextGrid can be found on the TextGrid Homepage.
Literature:
TextGrid. In: Heike Neuroth, Martina Kerzel, Wolfgang Gentzsch (Hrsg.): Die D-Grid Initiative. Universitätsverlag Göttingen, Göttingen 2007, ISBN 978-3-940344-01-4, S. 64–66 ([1]).
Heike Neuroth, Felix Lohmeier, Kathleen Marie Smith: TextGrid. Virtual Research Environment for the Humanities. In: The International Journal of Digital Curation. 6, Nr. 2, 2011, ISSN 1746-8256, S. 222–231 ([2]). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Boehm garbage collector**
Boehm garbage collector:
The Boehm–Demers–Weiser garbage collector, often simply known as Boehm GC, is a conservative garbage collector for C and C++ developed by Hans Boehm, Alan Demers, and Mark Weiser.Boehm GC is free software distributed under a permissive free software licence similar to the X11 license. The first paper introducing this collector appeared in 1992.
Design:
Hans Boehm describes the operation of the collector as follows: The collector uses a mark-sweep algorithm. It provides incremental and generational collection under operating systems which provide the right kind of virtual memory support. (Currently this includes SunOS[45], IRIX, OSF/1, Linux, and Windows, with varying restrictions.) It allows finalization code to be invoked when an object is collected. It can take advantage of type information to locate pointers if such information is provided, but it is usually used without such information.
Design:
Boehm GC can also run in leak detection mode in which memory management is still done manually, but the Boehm GC can check if it is done properly. In this way a programmer can find memory leaks and double deallocations.
Design:
Boehm GC is also distributed with a C string handling library called cords. This is similar to ropes in C++ (trees of constant small arrays), but instead of using reference counting for proper deallocation, it relies on garbage collection to free objects. Cords are good at handling very large texts, modifications to them in the middle, slicing, concatenating, and keeping history of changes (undo/redo functionality).
Operation:
The garbage collector works with most unmodified C programs, simply by replacing malloc() with GC_MALLOC() calls, replacing realloc() with GC_REALLOC() calls, and removing free() calls. The code piece below shows how one can use Boehm instead of traditional malloc and free in C.
For completeness, Boehm supports explicit deallocation via GC_FREE(). All the substitution can be done using preprocessor macros.
Uses and ports:
The Boehm GC is used by many projects that are implemented in C or C++ like Inkscape, as well as by runtime environments for a number of other languages, including Crystal, the Codon high performance python compiler, the GNU Compiler for Java runtime environment, the Portable.NET project, Embeddable Common Lisp, GNU Guile, the Mono implementation of the Microsoft .NET platform (also using precise compacting GC since version 2.8), GNUstep optionally, and libgc-d (a binding to libgc for the D programming language, used primarily in the MCI). It supports numerous operating systems, including many Unix variants (such as macOS) and Microsoft Windows, and provides a number of advanced features including incremental collection, parallel collection and a variety of finalizer semantics. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Porkchop plot**
Porkchop plot:
In orbital mechanics, a porkchop plot (also pork-chop plot) is a chart that shows contours of equal characteristic energy (C3) against combinations of launch date and arrival date for a particular interplanetary flight. The chart shows the characteristic energy ranges in zones around the local minima, which resembles the shape of a porkchop slice.
Porkchop plot:
By examining the results of the porkchop plot, engineers can determine when a launch opportunity exists (a 'launch window') that is compatible with the capabilities of a particular spacecraft. A given contour, called a porkchop curve, represents constant C3, and the center of the porkchop the optimal minimum C3. The orbital elements of the solution, where the fixed values are the departure date, the arrival date, and the length of the flight, were first solved mathematically in 1761 by Johann Heinrich Lambert, and the equation is generally known as Lambert's problem (or theorem).
Math:
The general form of characteristic energy can be computed as: where v ∞ {\textstyle v_{\infty }\,} is the orbital velocity when the orbital distance tends to infinity. Note that, since the kinetic energy is 1 2 m v 2 {\textstyle {\frac {1}{2}}mv^{2}} , C3 is in fact equal to twice the magnitude of the specific orbital energy, ϵ {\textstyle \epsilon } , of the escaping object.
Use:
For the Voyager program, engineers at JPL plotted around 10,000 potential trajectories using porkchop plots, from which they selected around 100 that were optimal for the mission objectives. The plots allowed them to reduce or eliminate planetary encounters taking place over the Thanksgiving or Christmas holidays, and to plan the completion of the mission's primary goals before the end of the fiscal year 1981. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Solar eclipse of March 20, 2034**
Solar eclipse of March 20, 2034:
A total solar eclipse will occur on Monday, March 20, 2034. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide.
Related eclipses:
Solar eclipses of 2033–2036 This eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.
Related eclipses:
Saros 130 This eclipse is a part of Saros cycle 130, repeating every 18 years, 11 days, containing 73 events. The series started with partial solar eclipse on August 20, 1096. It contains total eclipses from April 5, 1475 through July 18, 2232. There are no annular eclipses in the series. The series ends at member 73 as a partial eclipse on October 25, 2394. The longest duration of totality was 6 minutes, 41 seconds on July 11, 1619. All eclipses in this series occurs at the Moon’s descending node.
Related eclipses:
Tritos series This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee), but groupings of 3 tritos cycles (≈ 33 years minus 3 months) come close (≈ 434.044 anomalistic months), so eclipses are similar in these groupings.
Related eclipses:
Metonic series The metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles. Eclipses occur in nearly the same calendar date. In addition, the octon subseries repeats 1/5 of that or every 3.8 years (1387.94 days). All eclipses in this table occur at the Moon's descending node. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Tumor-like disorders of the lung pleura**
Tumor-like disorders of the lung pleura:
Tumor-like disorders of the lung pleura are a group of conditions that on initial radiological studies might be confused with malignant lesions. Radiologists must be aware of these conditions in order to avoid misdiagnosing patients. Examples of such lesions are: pleural plaques, thoracic splenosis, catamenial pneumothorax, pleural pseudotumor, diffuse pleural thickening, diffuse pulmonary lymphangiomatosis and Erdheim–Chester disease.
Pleural Plaque:
Pathophysiology Exposure to asbestos fibers reach the pleura of the lungs through the lymphatic channels or blood stream. Historically, ship builders and insulation workers are at greater risk.
Symptoms Affected persons are usually asymptomatic.
Diagnosis On radiological studies, pleural plaques are visualized using conventional chest x-rays and computed tomography scans (CT scans). The locations of the lesions are mostly in the parietal pleura of the lungs, especially in the posterior/lateral regions of the thorax, diaphragmatic domes, and lung fissures. In some cases, calcifications are also evident, especially with CT scans.
Treatment No treatment is required since pleural plaques are benign. However, studies have demonstrated that pleural plaques are an independent risk factor for developing bronchogenic carcinoma and/or mesothelioma.
Thoracic Splenosis:
Thoracic splenosis is splenosis that migrated to the thoracic cavity.
Pathophysiology Following thoracoabdominal trauma, most commonly a penetrating injury, laceration of the diaphragm, and spleen allows ectopic splenic tissue to reach the pleural space of the lung.
Symptoms Affected persons are usually asymptomatic. However, on rare occasions, thoracic splenosis can present with chest pain and/or hemoptysis.
Diagnosis On radiological studies, thoracic splenic lesions are visualized using CT scans. Visualized lesions can be described as solitary or multiple nodules. The locations of the lesions are mostly in the lower left pleural space and/or splenic bed. Confirmation can be done using scintigraphy with 99mTc tagged heat-damaged red blood cells.
Treatment No treatment is required since thoracic splenosis is a benign condition.
Catamenial pneumothorax:
Pathophysiology Ectopic endometrial tissue reaches the pleural space of the lung or the right hemi-diaphragmatic region and erodes the visceral pleura, causing the formation of a spontaneous pneumothorax. The condition is often cyclical, due to its associations with the beginning of the menstrual cycle.
Symptoms Affected persons usually present with recurrent spontaneous pneumothorax associated with the onset of the menstrual cycle. Additionally, chest/scapular pain and/or evidence of endometriosis in the abdominopelvic cavity are other manifestations.
Diagnosis On radiological studies, pneumothorax is visualized using conventional chest x-rays and CT scans. In 90% of the cases, the pneumothorax is located on the right side. In some cases, small nodules can be seen in the pleura using CT scans. Confirmation can be done using video assisted thoracoscopic surgery (VATS).
Treatment Treatment for the pneumothorax is with chest tube placement. As for the ectopic endometrial tissue, therapy with gonadotropin-releasing–hormone or resection of the lesions can improve symptoms.
Pleural Pseudotumor:
Pathophysiology Initial formation of a pleural effusion causes retraction of the lung lobules and widening of the fissures. This widening of the fissures allows the accumulation of liquid and the formation of a well-defined lenticular lesion.
Symptoms Affected persons usually present with signs of systemic fluid overload due to conditions such as congestive heart failure (CHF), cirrhosis or chronic kidney disease.
Diagnosis On radiological studies, a pleural pseudotumor is visualized as a biconcave or lenticular lesion using conventional chest x-rays and CT scans. The lesion is most commonly located in the minor (horizontal) fissure of the lung. A pleural pseudotumor is also associated with the presence of dependent pleural effusions.
Treatment Diuretics causes regression of the lesion.
Diffuse Pleural Thickening:
Pathophysiology Inflammatory pleuritis causes fusion of the parietal and visceral pleura of the lungs. In most cases, initial formation of empyema or hemothorax is the triggering factor for this inflammatory reaction. However, it can also be associated with connective tissue disorders and exposure to asbestos.
Symptoms Affected persons usually present with dyspnea.
Diagnosis On radiological studies, thickening of the pleura can be visualized extending along various rib levels using conventional chest x-rays and CT scans. The lesion usually has calcification, poorly defined and irregular borders, and associated blunting of the costophrenic angles.
Treatment No treatment is available.
Diffuse Pulmonary Lymphangiomatosis:
Pathophysiology Congenital anomaly causes abnormal proliferation and dilation of lymphatic channels.
Symptoms Affected persons are usually young adults that present with progressive dyspnea.
Diffuse Pulmonary Lymphangiomatosis:
Diagnosis On radiological studies, diffuse lesions are visualized throughout the thoracic cavity using CT scans. The location of the lesions is mostly in the upper lobes of the lungs, usually in a lymphatic distribution. Thickening of the pleura and interlobular septal is also evident. In addition, pleural/pericardial effusions and mediastinal fat infiltration is appreciated. Definitive diagnosis is achieved through tissue biopsy.
Diffuse Pulmonary Lymphangiomatosis:
Treatment Thoracentesis and pericardiocentesis are procedures performed to remove excess fluid in the pleural and pericardial spaces, respectively. There is evidence in the literature that chemotherapy and radiation therapy helps to improve symptoms. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Self-stereotyping**
Self-stereotyping:
Within social psychology self-stereotyping (or autostereotyping) is a process described as part of social identity theory (SIT) and, more specifically, self-categorization theory (SCT). Self-stereotyping occurs when an individual integrates commonly held characterizations (i.e. stereotypes or prototypes) of an in-group into their self-concept.According to SIT, group membership is most likely to influence self-concept and self-esteem when the cognitive processes of identification and categorization interact. In other words, when an individual identifies strongly with a group and categorizes him or herself as a member of that group, group membership becomes integrated into the person’s identity.
Description:
Self-stereotyping has also been characterized as an overlap between how a person represents their ingroup and how they represent the self. Prior to self-stereotyping, one experiences depersonalization, the process of shedding one's unique identity to merge it with the group identity of the in-group while simultaneously separating themselves from the out-group. Members of low-status groups have been found to be more prone to self-stereotyping than members of high-status groups. Research suggests that members of low-status groups attribute ingroup characteristics to the self via a deduction-to-the-self process. That is, they accept stereotypical characteristics (both positive and negative) of their ingroup as reflective of themselves. Latrofa and colleagues (2012) suggest self-stereotyping increases when low-status groups feel threatened and individuals within the group see more similarities between the group and themselves. Low-status groups' responses to threatening events are influenced by the collective emotion of the group. In contrast, it has been suggested that members of high-status groups tend to project their personal characteristics onto their ingroup using an induction-to-the-ingroup cognitive strategy.
Description:
Positive and negative Self-stereotyping can be characterized as negative and positive. Groups tend to be more accepting of positive stereotypes and ascribe it to themselves and their group, but reject negative stereotypes. However, negative self-stereotyping is sometimes accepted by individuals when it protects the individual from failure and poor judgment being ascribed to the performance of the individual rather than the group.
Description:
Implicit and explicit Self-stereotyping can also occur both implicitly and explicitly. Implicit self-stereotyping is when an individual unconsciously shifts their own beliefs to match that of their social group while explicit self-stereotyping is consciously shifting one’s behavioral traits to match their social group.
Factors:
Age Self-stereotyping emerges in early adolescence then decreases in young adulthood. It has been described as a form of depersonalization in which the self is viewed as a categorically interchangeable member of a salient ingroup. The growth of one’s social identity can directly relate to a decline in one's personal identity since conforming to group goals influences an individual's beliefs and behaviors.
Factors:
Gender Self-stereotyping by gender is seen in children as early as five-years-old. Research examining gender-based self-stereotyping has characterized female ingroups as low status and male ingroups as high status. This is because in modern society gender inequality still exists. Women have been shown to self-stereotype more than men, yet self-stereotyping decreases in men when presented with gender equality information. Coleman and Hong (2008) have pointed out that when women believe gender differences are attributed to biology differences between men and women, negative self-stereotyping also increases. Furthermore, implicit gender self-categorization has been identified as a key mechanism underlying the tendency of women to self-stereotype.
Factors:
Environment Self-stereotyping is not only limited to social group settings, it can also occur with environmental cues. In other words, when an individual is exposed to something in their environment that is relevant to their low status identity, they may shift their own beliefs or behaviors to fit the low status identity. The effects of environmental factors on self stereotyping among low status groups has been studied in gay men. A study found that being in a gay space, such as a gay bookstore, tended to make gay men identify very strongly with positive traits that are stereotypically gay. This pronounced self stereotyping trend was not found in the studied gay men in neutral spaces or heterosexual men.
Factors:
Culture Research has shown that individualist cultures engage in more self-stereotyping because they rely more on interpersonal relationships, group cohesion, and in-group ties compared to collectivist cultures.
Factors:
Group dynamic Some researchers have found that self-stereotyping is somewhat dependent upon an individual’s belief that he/she and the group are capable of change. If the individual believes that the group's needs are different from their own, they may have to adapt his/her self-representation in order to maintain membership within the in-group. However, if other in-group members are flexible to change, an individual is more likely to maintain his/her self-image and avoid self-stereotyping. Individuals tend to adapt to group characteristics more readily if they see this change as an enhancement to the self. Therefore, the individual's perception of the group influences how much he or she is willing to sacrifice in order to be a member.
Factors:
Bisexuality An essential aspect of self stereotyping in low status groups is the presence of a clear prototype. A study investigated the effect that self stereotyping had on bisexual people’s self esteem, identity uncertainty, mood, and stress. This study found that self-stereotyping did not cause bisexual individuals to experience the same well-being boosts observed when other individuals in low status groups, including gay and lesbian people, engage in self-stereotyping. These results may be attributed to the fact that bisexuality, due to being neither heterosexual nor homosexual, is an identity that lacks a distinct and clearly defined group; this absence of a clearly defined group means that there is no defined prototype.
Health:
Members of low status groups may experience prejudice, discrimination, and stress which may negatively impact their physical health. Self-stereotyping has been linked to affecting the physical and emotional health of low status group members who engage in more negative self-stereotyping. River and Paradez (2014) found that negative self-stereotyping can have a negative effect on the self-esteem of low status individuals, therefore making them more likely to experience obesity.
Implications:
Social influence Researchers have explored relationships between self-stereotyping and notable figures in low status groups. Rivera and Benitez (2016) found that when members of low status groups strongly identify with their low status identity and are shown positive examples of role models in their group, they engage in less self-stereotyping. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Transmedicalism**
Transmedicalism:
Transmedicalism is the idea that being transgender is primarily a medical issue related to the incongruence between an individual's assigned sex at birth and their gender identity, characterized by gender dysphoria. Transmedicalists believe individuals who identify as transgender without experiencing gender dysphoria or desiring to undergo a medical transition through methods such as hormone replacement therapy or sex reassignment surgery are not genuinely transgender. They may also exclude those who identify themselves as non-binary from the trans label.Transmedicalists are sometimes referred to as transmeds and truscum, a term coined by a user on microblogging website Tumblr, meaning "true transsexual scum", which has since been reappropriated. Those who believe that gender dysphoria is not required to be transgender are sometimes called tucute, meaning "too cute to be cisgender". Transmedicalists sometimes refer to those who identify as transgender without medicalized criteria as transtrenders.Some critics view transmedicalism akin to the medical model of disability in that it medicalizes an attribute that contains both medical and social components. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cover's theorem**
Cover's theorem:
Cover's theorem is a statement in computational learning theory and is one of the primary theoretical motivations for the use of non-linear kernel methods in machine learning applications. It is so termed after the information theorist Thomas M. Cover who stated it in 1965, referring to it as counting function theorem.
The Theorem:
The theorem expresses the number of homogeneously linearly separable sets of N points in D dimensions as an explicit counting function C(N,D) of the number of points N and the dimensionality D It requires, as a necessary and sufficient condition, that the points are in general position. Simply put, this means that the points should be as linearly independent (non-aligned) as possible. This condition is satisfied "with probability 1" or almost surely for random point sets, while it may easily be violated for real data, since these are often structured along smaller-dimensionality manifolds within the data space.
The Theorem:
The function C(N,D) follows two different regimes depending on the relationship between N and D For N≤D+1 , the function is exponential in N . This essentially means that any set of labelled points in general position and in number no larger than the dimensionality + 1 is linearly separable; in jargon, it is said that a linear classifier shatters any point set with N≤D+1 . This limiting quantity is also known as the Vapnik-Chervonenkis dimension of the linear classifier.For N>D+1 , the counting function starts growing less than exponentially . This means that, given a sample of fixed size N , for larger dimensionality D it is more probable that a random set of labelled points is linearly separable. Conversely, with fixed dimensionality, for larger sample sizes the number of linearly separable sets of random points will be smaller, or in other words the probability to find a linearly separable sample will decrease with N .A consequence of the theorem is that given a set of training data that is not linearly separable, one can with high probability transform it into a training set that is linearly separable by projecting it into a higher-dimensional space via some non-linear transformation, or: A complex pattern-classification problem, cast in a high-dimensional space nonlinearly, is more likely to be linearly separable than in a low-dimensional space, provided that the space is not densely populated.
Proof:
The proof of Cover's counting function theorem can be obtained from the recursive relation C(N+1,D)=C(N,D)+C(N,D−1).
Proof:
To show that, with fixed N , increasing D may turn a set of points from non-separable to separable, a deterministic mapping may be used: suppose there are N points. Lift them onto the vertices of the simplex in the N−1 dimensional real space. Since every partition of the samples into two sets is separable by a linear separator, the property follows. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**NLRP5**
NLRP5:
NLRP5, short for NOD-like receptor family pyrin domain containing 5, is an intracellular protein that plays a role in early embryogenesis. NLRP5 is also known as NACHT, LRR and PYD domains-containing protein 5 (NALP5), Mater protein homolog (MATER), PYPAF8, PAN11, and CLR19.8, and is one of 14 pyrin domain containing members of the NOD-like receptor family of cytoplasmic receptors known to mammals.
NLRP5:
In humans, the NLRP5 protein is encoded by the NLRP5 gene. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Aerodynamic force**
Aerodynamic force:
In fluid mechanics, an aerodynamic force is a force exerted on a body by the air (or other gas) in which the body is immersed, and is due to the relative motion between the body and the gas.
Force:
There are two causes of aerodynamic force: : §4.10 : 29 the normal force due to the pressure on the surface of the body the shear force due to the viscosity of the gas, also known as skin friction.Pressure acts normal to the surface, and shear force acts parallel to the surface. Both forces act locally. The net aerodynamic force on the body is equal to the pressure and shear forces integrated over the body's total exposed area.When an airfoil (such as a wing) moves relative to the air, it generates an aerodynamic force in a rearward direction, at an angle determined by the direction of relative motion. This aerodynamic force is commonly resolved into two components, both acting through the center of pressure:: 14 : § 5.3 drag is the force component parallel to the direction of relative motion, lift is the force component perpendicular to the direction of relative motion.In addition to these two forces, the body may experience an aerodynamic moment.
Force:
The force created by propellers and jet engines is called thrust, and is also an aerodynamic force (since it acts on the surrounding air). The aerodynamic force on a powered airplane is commonly represented by three vectors: thrust, lift and drag.: 151 : § 14.2 The other force acting on an aircraft during flight is its weight, which is a body force and not an aerodynamic force. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**TAE connector**
TAE connector:
TAE (Telekommunikations-Anschluss-Einheit or telecommunications connection unit) is the German standard for telephone plugs and sockets.
The standard covers two TAE types: F ("Fernsprechgerät": for telephones) and N ("Nebengerät" or "Nichtfernsprechgerät": for other devices such as answering machines and modems). U coded sockets and plugs are universal connectors that are suitable for both device types.
E-coded connectors that are used in EAD-sockets are not intended for telephony applications.
History:
The TAE system was introduced in the late 1980s before the German government-owned institution Deutsche Bundespost (DBP, German Federal Post) was divided into Deutsche Post (postal service), Deutsche Telekom (telecommunication services) and Postbank (financial services). Previously, the older ADo type connectors had been used, or telephones had been hardwired to their (VDo) wall sockets, and only officially approved telephones (legally distributable only by the DBP) were allowed to be connected to the telephone system. Furthermore, telephones and other communication devices could only be leased from the DBP and not be sold or bought on the free market.
History:
The introduction of the TAE system was the practical enabling technology of the legal specification in Germany that communication terminal equipment should be in the responsibility of end users. Subsequently, many communication devices became available in the open market that could be plugged into standard TAE sockets. Adaptors allow for connecting devices with registered jacks that are more prevalent internationally.
History:
Today, TAE connectors are common in Germany and other central European countries like Liechtenstein and Luxembourg. Modern TAE sockets also contain circuits referred to as passiver Prüfabschluss, meaning passive test termination. This provides a discernible condition to the telephone exchange indicating that the line is continuous to the TAE-connected device.
TAE socket:
A typical TAE installation is a multi-socket junction box with at least one N connector and one F connector socket in the box, but having usually two N and one F connector. Up to three N connectors are possible. Network service enters the box and connects to pins 1 and 2 on the right-most N connector. Service is daisy-chained from pins 5 and 6 on the N connector to pins 1 and 2 on the next N connector to the left. The F connector is attached to pins 5 and 6 on the last N connector at the end of the chain.
TAE plug:
(Image shown with flat side of connector down and the metallic pins facing you. The cable pigtail exits at the bottom of the connector) When wiring a TAE plug, a mirror image of the illustration (pins 1 through 3 are on the left side) should be used, if wiring the connector with the flat side up.
Observations:
As the TAE connector does not have gold contacts, the contacts may oxidize, which can cause sizzling and crackling noises in analog voice transmission.
Looping the a2 and b2 wires out of the TAE is related to the routing the line through instruments in a house in order that no extension may overhear another. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Secondary fermentation (wine)**
Secondary fermentation (wine):
Secondary fermentation is a process commonly associated with winemaking, which entails a second period of fermentation in a different vessel than the one used to start the fermentation process. An example of this would be starting fermentation in a carboy or stainless steel tank and then moving it over to oak barrels. Rather than being a separate, second fermentation, this is most often one single fermentation period that is conducted in multiple vessels. However, the term does also apply to procedures that could be described as a second and distinct fermentation period.
In wine production:
In sparkling wine production, the secondary fermentation often takes places in the wine bottle that the wine will be sold in. This is most commonly known as the méthode champenoise or "Champagne method" after the region most noted for sparkling wine production. When the base wine (or cuvee) has been produced from single grape varietals or a blend, the wine is bottled with a mixture of yeast and fresh sugar known as the "liqueur de tirage". This secondary fermentation, also known as bottle fermentation, is the process that makes the wine "bubbly" due to the containment of carbon dioxide which is normally released as a by product in regular fermentation. In still wine production, particularly of red wines and some white wines like Chardonnay, the secondary fermentation process can also usher in the use of malolactic fermentation (or MLF) where the hard, green apple-like malic acid is converted into softer, butter-like lactic acid. In the case of a stuck fermentation, a winemaker may wish to transfer the must to a second vessel and use stronger, more aggressive yeasts with high fermentation temperatures to re-initiate the fermentation process. A similar process known as governo has been used by Tuscan winemakers since the 14th century with the isolation after harvest of a batch of grapes that can be added later to the wine to help prevent (or recover from) a stuck fermentation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Space-time adaptive processing**
Space-time adaptive processing:
Space-time adaptive processing (STAP) is a signal processing technique most commonly used in radar systems. It involves adaptive array processing algorithms to aid in target detection. Radar signal processing benefits from STAP in areas where interference is a problem (i.e. ground clutter, jamming, etc.). Through careful application of STAP, it is possible to achieve order-of-magnitude sensitivity improvements in target detection.
Space-time adaptive processing:
STAP involves a two-dimensional filtering technique using a phased-array antenna with multiple spatial channels. Coupling multiple spatial channels with pulse-Doppler waveforms lends to the name "space-time." Applying the statistics of the interference environment, an adaptive STAP weight vector is formed. This weight vector is applied to the coherent samples received by the radar.
History:
The theory of STAP was first published by Lawrence E. Brennan and Irving S. Reed in the early 1970s. At the time of publication, both Brennan and Reed were at Technology Service Corporation (TSC). While it was formally introduced in 1973, it has theoretical roots dating back to 1959.
Motivation and applications:
For ground-based radar, cluttered returns tend to be at DC, making them easily discriminated by Moving Target Indication (MTI). Thus, a notch filter at the zero-Doppler bin can be used. Airborne platforms with ownship motion experience relative ground clutter motion dependent on the angle, resulting in angle-Doppler coupling at the input. In this case, 1D filtering is not sufficient, since clutter can overlap the desired target's Doppler from multiple directions. The resulting interference is typically called a "clutter ridge," since it forms a line in the angle-Doppler domain. Narrowband jamming signals are also a source of interference, and exhibit significant spatial correlation. Thus receiver noise and interference must be considered, and detection processors must attempt to maximize the signal-to-interference and noise ratio (SINR).
Motivation and applications:
While primarily developed for radar, STAP techniques have applications for communications systems.
Basic theory:
STAP is essentially filtering in the space-time domain. This means that we are filtering over multiple dimensions, and multi-dimensional signal processing techniques must be employed. The goal is to find the optimal space-time weights in NM -dimensional space, where N is the number of antenna elements (our spatial degrees of freedom) and M is the number of pulse-repetition interval (PRI) taps (our time degrees of freedom), to maximize the signal-to-interference and noise ratio (SINR). Thus, the goal is to suppress noise, clutter, jammers, etc., while keeping the desired radar return. It can be thought of as a 2-D finite-impulse response (FIR) filter, with a standard 1-D FIR filter for each channel (steered spatial channels from an electronically steered array or individual elements), and the taps of these 1-D FIR filters corresponding to multiple returns (spaced at PRI time). Having degrees of freedom in both the spatial domain and time domain is crucial, as clutter can be correlated in time and space, while jammers tend to be correlated spatially (along a specific bearing).A simple, trivial example of STAP is shown in the first figure, for 10 . This is an idealized example of a steering pattern, where the response of the array has been steered to the ideal target response, s . Unfortunately, in practice, this is oversimplified, as the interference to be overcome by steering the nulls shown is not deterministic, but statistical in nature. This is what requires STAP to be an adaptive technique. Note that even in this idealized example, in general, we must steer over the 2-D angle-Doppler plane at discrete points to detect potential targets (moving the location of the 2-D sinc main lobe shown in the figure), and do so for each of the range bins in our system.
Basic theory:
The basic functional diagram is shown to the right. For each antenna, a down conversion and analog-to-digital conversion step is typically completed. Then, a 1-D FIR filter with PRI length delay elements is used for each steered antenna channel. The lexicographically ordered weights W1 to WNM are the degrees of freedom to be solved in the STAP problem. That is, STAP aims to find the optimal weights for the antenna array. It can be shown, that for a given MN×MN interference covariance matrix, R , the optimal weights maximizing the SINR are calculated as W=κR−1s where κ is a scalar that does not affect the SINR. The optimal detector input is given by: y=Wx where x is a space-time snap-shot of the input data. The main difficulty of STAP is solving for and inverting the typically unknown interference covariance matrix, R . Other difficulties arise when the interference covariance matrix is ill-conditioned, making the inversion numerically unstable. In general, this adaptive filtering must be performed for each of the unambiguous range bins in the system, for each target of interest (angle-Doppler coordinates), making for a massive computational burden. Steering losses can occur when true target returns do not fall exactly on one of the points in our 2-D angle-Doppler plane that we've sampled with our steering vector s
Approaches:
The various approaches can be broken down by processing taxonomy, or by simplifying the data space / data sources.
Approaches:
Direct methods The optimum solution is using all degrees of freedom by processing the adaptive filter on the antenna elements. For adaptive direct methods, Sample Matrix Inversion (SMI) uses the estimated (sample) interference covariance matrix in place of the actual interference covariance matrix. This is because the actual interference covariance matrix is not known in practice. If it is known by some means, then it need not be estimated, and the optimal weights are fixed. This is sometimes called the data-independent variation. The data-dependent variation estimates the interference covariance matrix from the data. In MIMO communications systems, this can be done via a training sequence. The clairvoyant detector is given when the covariance matrix is known perfectly and defined as: Rk=E[xkxkH]|H0 where xk is the space-time snapshot statistic for the kth range cell under the interference only hypothesis, H0 . For SMI, the interference covariance matrix for the kth range cell consisting of the statistics from interfering noise, clutter, and jammers is estimated as follows: R^k=1P∑m=0P−1xmxmH where xm is the training data obtained from the input processor for the mth range cell. Therefore, space-time snapshots surrounding the desired range cell are averaged. Note that the desired range cell space-time snapshot is typically excluded (as well as a number of additional cells, or "guard cells") to prevent whitening of the statistics.The main problem with direct methods is the great computational complexity associated with the estimation and inversion of matrices formed from many degrees of freedom (large number of elements and or pulses). In addition, for methods where R must be estimated using data samples, the number of samples required to achieve a particular error is heavily dependent on the dimensionality of the interference covariance matrix. As a result, for high dimensional systems, this may require an unachievable number of unambiguous range cells. Further, these adjacent data cells must contain stationary statistics as a function of range which is rarely a good assumption for the large number of cells required ( 2NM for 3 dB SINR degradation from optimal, clairvoyant STAP).
Approaches:
Reduced rank methods Reduced rank methods aim to overcome the computational burdens of the direct method by reducing the dimensionality of the data or the rank of the interference covariance matrix. This can be accomplished by forming beams and performing STAP on the beamspace. Both pre and post Doppler methods can be used in the beamspace. Post Doppler methods may also be used on the full antenna element input as well to reduce the data in this dimension only. A popular example is displaced phase center antenna (DPCA), which is a form of data-independent STAP in the beamspace, pre-Doppler. The goal is to perform beamforming such that the beam appears stationary as the airborne radar is in motion over discrete time periods so the clutter appears without Doppler. However, phase errors can cause significant degradation since the algorithm is not adaptive to the returned data. Many other methods may be used to reduce the rank of the interference covariance matrix, and so all methods in the reduced rank category can be thought of as simplifying the covariance matrix to be inverted: R⇒R~ Post-Doppler methods decompose the STAP problem from an MN×MN adaptive filtering problem to M individual adaptive filters of length N (an N×N adaptive filter problem). By performing fixed Doppler processing, the adaptive filters become spatial only. Since the target response is already steered to a specified angle-Doppler location, the dimensionality can be reduced by pre-processing multiple Doppler bins and angles surrounding this point. In addition to reducing the dimensionality of the adaptive processor, this in turn reduces the number of required training data frames when estimating the interference covariance matrix since this quantity is dimension dependent.Since these methods reduce the data dimensionality, they are inherently sub-optimal. There are a number of techniques to compare the performance of reduced-rank methods and estimated direct methods to clairvoyant STAP (direct with perfect knowledge of interference covariance matrix and target steering vector), mostly based around SINR loss. One such example is SINR SINR |W=Wopt where we've taken the ratio of the SINR evaluated with the sub-optimal weights W^ and the SINR evaluated with the optimal weights Wopt . Note in general this quantity is statistical and the expectation must be taken to find the average SINR loss. The clairvoyant SINR loss may also be calculated by taking the ratio of the optimal SINR to the system SNR, indicating the loss due to interference.
Approaches:
Model based methods There are also model based methods that attempt to force or exploit the structure of the covariance interference matrix. The more generally applicable of these methods is the covariance taper matrix structure. The goal is to compactly model the interference, at which point it can then be processed using principal component techniques or diagonal-loading SMI (where a small magnitude, random diagonal matrix is added to attempt to stabilize the matrix prior to inverting). This modeling has an added benefit of decorrelating interference subspace leakage (ISL), and is resistant to internal clutter motion (ICM). The principal component method firsts applies principal component analysis to estimate the dominant eigenvalues and eigenvectors, and then applies a covariance taper and adds an estimated noise floor: R~PC−CMT=(∑m=0P−1λmvmvmH)∘T+σn2 where λm is the mth eigenvalue estimated using PCA, vm is the associated mth eigenvector estimated using PCA, A∘B implies element-by-element multiplication of matrices A and B , T is the estimated covariance matrix taper, and σn2 is the estimated noise floor. The estimation of the covariance taper T can be complicated, depending on the complexity of the underlying model attempting to emulate the interference environment. The reader is encouraged to see for more information on this particular subject. Once this taper is sufficiently modeled, it may also be applied to the more simple SMI adaptation of CMT as follows: R~SMI−CMT=R~SMI∘T+δI where R~SMI is the typical SMI estimated matrix seen in the approximate direct method, δ is the diagonal loading factor, and I is the identity matrix of the appropriate size. It should be seen that this is meant to improve the standard SMI method where SMI uses a smaller number of range bins in its average than the standard SMI technique. Since fewer samples are used in the training data, the matrix often requires stabilization in the form of diagonal loading.More restrictive examples involve modeling the interference to force Toeplitz structures, and can greatly reduce the computational complexity associated with the processing by exploiting this structure. However, these methods can suffer due to model-mismatch, or the computational savings may be undone by the problem of model fitting (such as the nonlinear problem of fitting to a Toeplitz or block-Toeplitz matrix) and order estimation.
Modern applications:
Despite nearly 40 years of existence, STAP has modern applications.
Modern applications:
MIMO communications For dispersive channels, multiple-input multiple-output communications can formulate STAP solutions. Frequency-selective channel compensation can be used to extend traditional equalization techniques for SISO systems using STAP. To estimate the transmitted signal S^ at a MIMO receiver, we can linearly weight our space-time input Z~ with weighting matrix W~ as follows S^=W~TZ~ to minimize the mean squared error (MSE). Using STAP with a training sequence S~ , the estimated optimal weighting matrix (STAP coefficients) is given by: W~≈(Z~Z~T)Z~S~T MIMO radar STAP has been extended for MIMO radar to improve spatial resolution for clutter, using modified SIMO radar STAP techniques. New algorithms and formulations are required that depart from the standard technique due to the large rank of the jammer-clutter subspace created by MIMO radar virtual arrays, which typically involves exploiting the block diagonal structure of the MIMO interference covariance matrix to break the large matrix inversion problem into smaller ones. In comparison with SIMO radar systems, which will have M transmit degrees of freedom, and NL receive degrees of freedom, for a total of M+NL , MIMO radar systems have MNL degrees of freedom, allowing for much greater adaptive spatial resolution for clutter mitigation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Slicer (3D printing)**
Slicer (3D printing):
A slicer is toolpath generation software used in the majority of 3D printing processes for the conversion of a 3D object model to specific instructions for the printer. In particular, the conversion from a model in STL format to printer commands in g-code format in fused filament fabrication and other similar processes.The slicer first divides the object as a stack of flat layers, followed by describing these layers as linear movements of the 3D printer extruder, fixation laser or equivalent. All these movements, together with some specific printer commands like the ones to control the extruder temperature or bed temperature, are finally written in the g-code file, that can afterwards be transferred to the printer.
Additional features of the slicer:
Nearly all slicers have some additional features, like: Infill: solid objects need a large amount of valuable material (filament, ...) and print time. The slicer can automatically convert solid volumes to hollow ones, saving costs and time. The hollow object can be partially filled by internal structures, as internal walls, to provide additional robustness. The amount of these structures is called infill density, this parameter being one of the adjustments to be provided to the slicer.Supports: most of the 3D printing processes create the object layer by layer, down to up, with the layer under construction being deposited over the previous one. As a consequence, all object parts must overlie, at least in some part, over another one. In the case of an object layer that is floating (by example, the flat roof of a house or an horizontally extended arm in a figure), the slicer automatically can add supports for it. The support touches the object in a way that is easily detachable from it at the finish stage of the object production.Rafts, skirts and brims: printing of the first object layer, the one in contact with the printer bed, has some peculiarities, like problems of object adherence to the bed, rugosity, smooth deposition of the first amounts of filament, .... The slicer can automatically add some detachable structures to minimize these problems. Usual types of these base structures are a skirt (a single band around the base of the object without touching it), a brim (several lines of filament around the base of the object, touching it but not under it, and radiating outwards) and rafts (several layers of material that form a detachable base, with the object printed over it).
List of slicer software:
There's a wide collection of slicer applications, some of them free and open-source. Some of the most used ones are: | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Variable Assembly Language**
Variable Assembly Language:
Variable Assembly Language (VAL) is a computer-based control system and language designed specifically for use with Unimation Inc. industrial robots.
Variable Assembly Language:
The VAL robot language is permanently stored as a part of the VAL system. This includes the programming language used to direct the system for individual applications. The VAL language has an easy to understand syntax. It uses a clear, concise, and generally self-explanatory instruction set. All commands and communications with the robot consist of easy to understand word and number sequences. Control programs are written on the same computer that controls the robot. As a real-time system, VAL's continuous trajectory computation permits complex motions to be executed quickly, with efficient use of system memory and reduction in overall system complexity. The VAL system continuously generates robot control commands, and can simultaneously interact with a human operator, permitting on-line program generation and modification.
Variable Assembly Language:
A convenient feature or VAL is the ability to use libraries or manipulation routines. Thus, complex operations may be easily and quickly programmed by combining predefined subtasks.
The VAL language consists of monitor commands and program instructions.
The monitor commands are used to prepare the system for execution of user-written programs. Program instructions provide the repertoire necessary to create VAL programs for controlling robot actions.
Terminology:
The following terms are frequently used in VAL related operations.
Monitor The VAL monitor is an administrative computer program that oversees operation of a system. It accepts user input and initiates the appropriate response; follows instructions from user-written programs to direct the robot; and performs the computations necessary to control the robot.
Editor The VAL editor is an aid for entering information into a computer system, and modifying existing text. It is used to enter and modify robot control programs. It has a list of instructions telling a computer how to do something. VAL programs are written by system users to describe tasks the robot is to perform.
Location Location is a position of an object in space, and the orientation of the object. Locations are used to define the positions and orientations the robot tool is to assume during program execution.
VAL programming:
Several conventions apply to numerical values to be supplied to VAL commands and instructions. Preceding each monitor-command description are two symbols indicating when the command can be typed by the user. A dot (.) signifies the command can be performed when VAL is in its top-level monitor mode and no user program being executed (that is, when the system prompt is a dot). An asterisk (*) indicates the command can be performed at the same time VAL is executing the program (that is, when the system prompt is an asterisk). If both symbols are present the command can be executed in either case. Most monitor commands and program instructions can be abbreviated. When entering any monitor command or program instruction, the function name can be abbreviated to as many characters as are necessary to make the name unique.
VAL programming:
For commands and instructions, angle brackets, < >, are used to enclose an item which describes the actual argument to appear. Thus the programmer can supply the appropriate item in that position when entering the command or instruction. Note that these brackets used here are for clarification, and are never to be included as part of a command or instruction.
VAL programming:
Many VAL commands and instructions have optional arguments. For notations, optional arguments are enclosed in square brackets, [ ]. If there is a comma following such an argument, the comma must be retained if the argument is omitted, unless nothing follows. For example, the monitor BASE command has the form: BASE [<dx>] , [<dy>] , [<dz>] , [<rotation>] To specify only a 300-millimeter change in the Z direction, the command could be entered in any of the following ways: BASE 0,0,300,0 BASE ,,300, BASE ,,300Note that the commas preceding the number 300 must be present to correctly to relate the number with a Z-direction change. Like angle brackets, square brackets are never entered as part of a command or instruction.
VAL programming:
Several types of numerical arguments can appear in commands and instructions. For each type there are restrictions on the values that are accepted by VAL. The following rules should be observed: Distances are entered to define locations to which the robot is to move. The unit of measure for distances is millimeter, although units are never explicitly entered for any value. Values entered for distances can be positive or negative, with their magnitudes limited by a number representative of the maximum reach of the robot (for example, 1024 mm and 700 mm for the PUMA 500 and PUMA 250 robots, respectively). Within the resultant range, distance values can be specified in increments of 0.01 mm. Note, however, that some values cannot be represented internally, and are stored as the nearest representable value.
VAL programming:
Angles in degrees are entered to define and modify orientations the robot is to assume at named locations, and to describe angular positions of robot joints. Angle values can be positive or negative, with their magnitudes limited by 1800 or 3600 depending on the usage. Within the range, angle values can be specified in increments of 0.01°. Values cannot be represented internally, however they are stored asnearest representable value.
The VAL system:
The function of VAL is to regulate and control a robot system by following user commands or instructions. In addition to being a compact stand-alone system, VAL has been designed to be highly interactive to minimize programing time, and to provide as many programming aids as possible.
The VAL system:
External communication The standard VAL system uses an operator's console terminal and manual control box to input commands and data from the user. The operator console serves as the primary communication device and can be either a direct play terminal or a printing terminal. Interaction with other devices in an automated cell is typically handled by monitoring input channels and switching outputs. By this means the robot can control a modest cell without the need for other programmable devices.
The VAL system:
VAL Operating System The controller has two levels or operation: the top level is called the VAL operating system, or monitor, because it administers operations of the system, including interaction with the user; the second level is used for diagnostic work on the controller hardware. The system monitor is a computer program stored VAL programmable read-only memory (PROM) in the Computer/Controller.PROM memory retains its contents finitely, and thus VAL is immediately available when the controller is switched on. The monitor is responsible for control of the robot, and its commands come from the manual control unit, the system terminal, or from programs. To increase its versatility and flexibility, the VAL monitor can perform of its commands even while a user program is being executed. Commands that can be processed in this way include those for controlling the status of the system, defining robot locations, storing and retrieving information on the floppy disk, and creating and editing robot control programs. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Myerson–Satterthwaite theorem**
Myerson–Satterthwaite theorem:
The Myerson–Satterthwaite theorem is an important result in mechanism design and the economics of asymmetric information, and named for Roger Myerson and Mark Satterthwaite. Informally, the result says that there is no efficient way for two parties to trade a good when they each have secret and probabilistically varying valuations for it, without the risk of forcing one party to trade at a loss.
Myerson–Satterthwaite theorem:
The Myerson–Satterthwaite theorem is among the most remarkable and universally applicable negative results in economics—a kind of negative mirror to the fundamental theorems of welfare economics. It is, however, much less famous than those results or Arrow's earlier result on the impossibility of satisfactory electoral systems.
Notation:
There are two agents: Sally (the seller) and Bob (the buyer). Sally holds an item that is valuable for both her and Bob. Each agent values the item differently: Bob values it as vB and Sally as vS . Each agent knows his/her own valuation with certainty, but knows the valuation of the other agent only probabilistically: For Sally, the value of Bob is represented by a probability density function fB which is positive in the range [B_,B¯] . The corresponding cumulative distribution function is FB For Bob, the value of Sally is represented by a probability density function fS which is positive in the range [S_,S¯] . The corresponding cumulative distribution function is FS .A direct bargaining mechanism is a mechanism which asks each agent to report his/her valuation of the item, then decides whether the item will be traded and at what price. Formally, it is represented by two functions: The trade-probability function, t(vB′,vS′) , determines the probability that the item will be transferred from the seller to the buyer (in a deterministic mechanism, this probability is either 0 or 1, but the formalism also allows random mechanisms).
Notation:
The price function, p(vB′,vS′) , determines the price that Bob should pay to Sally. Note that the reported values are marked by v′ since they do not equal the real values.Note that, thanks to the revelation principle, the assumption that the mechanism is direct does not lose generality.
Notation:
Every agent knows his value and knows the mechanism. Hence, every agent can calculate his expected gain from the trade. Since we are interested in mechanisms which are truthful in equilibrium, we assume that each agent assumes that the other agent is truthful. Hence: For Sally, the expected gain is the expected payment minus the expected loss from giving the object: US(vS,vS′)=∫uB=B_B¯p(vS′,uB)fB(uB)duB−vS∫uB=B_B¯t(vS′,uB)fB(uB)duB For Bob, the expected gain is the expected gain from getting the object minus the expected payment: UB(vB,vB′)=vB∫uS=S_S¯t(uS,vB′)fS(uS)duS−∫uS=S_S¯p(uS,vB′)fS(uS)duS
Requirements:
Myerson and Satterthwaite study the following requirements that an ideal mechanism should satisfy (see also Double auction#requirements): 1. individual rationality (IR): The expected value of both Bob and Sally should be non-negative (so that they have an initial incentive to participate). Formally: US(vS,vS)≥0 and UB(vB,vB)≥0 2. Weak balanced budget (WBB): The auctioneer should not have to bring money from home in order to subsidize the trade.
Requirements:
3. Nash equilibrium incentive compatibility (NEIC): for every agent, if the other agent reports the true value, then the best response is to report the true value too. In other words, no one should want to lie. Formally: ∀vs′:US(vS,vS)≥US(vS,vS′) and ∀vB′:UB(vB,vB)≥UB(vB,vB′) 4. ex-post Pareto efficiency (PE): the item should be finally given to the agent who values it the most. Formally: t(vB,vS)=1 if vB>vS and t(vB,vS)=0 if vB<vS
Statement:
If the following two assumptions are true: The intervals [B_,B¯] and [S_,S¯] have a non-empty intersection.
The probability densities for the valuations are strictly positive on those intervals.then, there is no mechanism which satisfies the four properties mentioned above (IR, WBB, NEIC and PE).
Extensions:
Various variants of the Myerson–Satterthwaite setting have been studied.
1. Myerson and Satterthwaite considered a single buyer and a single seller. When there are many buyers and sellers, the inefficiency asymptotically disappears.
Extensions:
However, this is only true in the case of private goods; in the case of public goods the inefficiency is aggravated when the number of agents becomes large.2. Myerson and Satterthwaite considered an asymmetric initial situation, in the sense that at the outset one party has 100% of the good and the other party has 0% of the good. It has been shown that ex post efficiency can be attained if initially both parties own 50% of the good to be traded.3. The latter result has been extended to settings in which the parties can make unobservable ex ante investments in order to increase their own valuations. Yet, ex post efficiency cannot be achieved if the seller's unobservable investment increases the buyer's valuation, even if only the buyer has private information about his or her valuation.4. Another impossibility result where only one party has private information about its valuation can be shown to hold when the outside option payoffs are not exogenously given. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Self-balancing scooter**
Self-balancing scooter:
A self-balancing scooter (also hoverboard, self-balancing board, segway or electric scooter board) is a self-balancing personal transporter consisting of two motorized wheels connected to a pair of articulated pads on which the rider places their feet. The rider controls the speed by leaning forward or backward, and direction of travel by twisting the pads.
Invented in its current form in early 2013, the device is the subject of complex patent disputes. Volume manufacture started in China in 2014 and early units were prone to catching fire due to an overheating battery which resulted in product recalls in 2016, including over 500,000 units sold in the United States by eight manufacturers.
History:
Shane Chen, an American businessman and founder of Inventist filed a patent for a device of this type in February 2013 and launched a Kickstarter fund-raising campaign in May 2013.The devices' increasing popularity in Western countries has been attributed, initially, to endorsement by the wide array of celebrities (including Justin Bieber, Jamie Foxx, Kendall Jenner, Chris Brown, Soulja Boy and Wiz Khalifa). The founders of the American company PhunkeeTree encountered the board at the Hong Kong Electronics Show in 2014 and became involved in its distribution shortly thereafter.By June 2015, the board was being made by several manufacturers, mainly in the Shenzhen region of China. In January 2015 through Inventist, he announced his intention to pursue litigation In April 2015, Ninebot, a significant manufacturer of devices acquired Segway Inc. (which separately asserted that it holds patents for self-balancing scooters.) in order to resolve the dispute. In May Chen voiced his frustrations regarding patent rights in China. In August 2015, Mark Cuban announced plans to purchase the Hovertrax patents from Chen. Many of the units provided in the first year of manufacture were defective and likely to catch fire, resulting in a major product recall from multiple manufacturers during 2016 (more details below).In June 2016 the U.S. International Trade Commission issued an injunction for patent infringement against UPTECH, U.P. Technology, U.P. Robotics, FreeGo China, EcoBoomer, and Roboscooters. Robstep, INMOTION, Tech in the City, FreeGo settled with Segway.
Etymology of "hoverboard":
The use of the term "hoverboard" to describe these devices, despite the fact that they do not hover, has led to considerable discussion in the media.The first use of the term for can be traced back to a 1967 science fiction novel by M. K. Joseph and subsequently popularized in the 1989 film, Back to the Future Part II where Marty McFly uses one after traveling to 2015. While the first trademarked use of hoverboard was registered in 1996 as a collecting and trading game, its first use as a commercial name representing a wheeled scooter was in 1999, and Guinness World Records lists a farthest hoverboard flight entry. In September 2015 the Oxford English Dictionary stated in their view the term had not been in use in the context for long enough for inclusion and that for the time being they would restrict their description to boards "that Marty McFly would recognize". The term "self-balancing electric scooter" remains popular.
Design and operation:
The device has three 6.5 inches (170 mm), 8 inches (200 mm), 10 inches (250 mm) diameter wheel variants connected to a self-balancing control mechanism using built-in gyroscopic and a sensor pad. By tilting the pad the rider can control the speed and direction of travel achieving speeds from 6 to 15 miles per hour (9.7 to 24 km/h) with a range of up to 15 miles (24 km) dependent on model, terrain, rider weight and other factors.As with most wheeled vehicles where the rider is exposed, Consumer Reports has recommended that users wear appropriate safety gear while using them.In 2019, hoverboards now feature a self balancing mode, in which the motors automatically engage the gyroscope in the opposite direction. This way, when the rider leans forward or backward the board is always attempting to level itself, making it easier to ride than its 2016 predecessors.
Issues and incidents:
There were many instances of units catching fire, with claims that they were responsible for numerous residential fires between late 2015 into 2016. In the United Kingdom, authorities expressed concerns with the boards, regarding possible faulty wiring. Many airlines banned the transportation of the boards, both as stored or carry-on luggage.The US Consumer Product Safety Commission (CPSC) launched an investigation into the safety of the device in late 2015 and determined that the lithium-ion battery packs in the self-balancing scooters/hoverboards could overheat and posed a risk of catching fire or exploding, and that defects had led to 60 fires in over 20 states. In July 2016 the commission ordered the recall of over 500,000 units from eight manufacturers. The Swagway model X1 constituted the majority of the recalled "hoverboards," at 267,000 units.In January 2016, the Philippine Department of Health and Trade and Industry issued a joint advisory cautioning the public against buying them, due to reports of injuries and "potential electrocution connected with its usage". The advisory also stated “as a precautionary measure, the DOH and DTI-Consumer Protection Group therefore advise parents against buying hoverboards for children under 14 years of age.”In May 2016, the miniPRO produced by Segway Inc. received UL certification, as did a company in Shenzhen, China. In June 2016, after safety improvements in design, the UL-approved Swagtron was launched in the United States.In March 2017, a self-balancing board was found to be the cause for a fire that killed two children in Harrisburg.In 2018, a self-balancing board was blamed for a fire that severely damaged a Michigan home.In March 2023, a self-balancing board was recalled for causing an April 2022 fire in Hellertown, Pennsylvania that killed two sisters. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Devil's food cake**
Devil's food cake:
Devil's food cake is a moist, rich chocolate layer cake. It is considered a counterpart to the white or yellow angel food cake. Because of differing recipes and changing ingredient availability over the 20th century, it is difficult to precisely qualify what distinguishes devil's food from the more standard chocolate cake. However, it traditionally has more chocolate than a regular chocolate cake, making it darker in colour and with a heavier texture. The cake is usually paired with a rich chocolate frosting.
Devil's food cake:
Devil's food cake was invented in the United States in the early twentieth century, with the recipe in print as early as 1905.
Ingredients:
Devil's food cake traditionally uses unsweetened chocolate baking squares in lieu of unsweetened cocoa powder. However, contemporary recipes typically use cocoa powder for its convenience over the more traditional chocolate baking squares. Also, because of its reduced amount of cocoa butter, cocoa powder has a more intense chocolate flavor than unsweetened chocolate. Moreover, coffee is frequently added as a liquid to enhance the chocolate flavor. Some recipes use hot or boiling water as the cake's main liquid, rather than milk. Its antithetical counterpart, the angel food cake, is a very light white cake that uses stiffly beaten egg whites and no dairy.
Ingredients:
Devil's food cake is sometimes distinguished from other chocolate cakes by the use of additional baking soda (sodium bicarbonate), which raises the pH level and makes the cake a deeper and darker mahogany color. Devil's food cake incorporates butter (or a substitute), flour, and less egg than other chocolate cakes. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Exometabolomics**
Exometabolomics:
Exometabolomics, also known as 'metabolic footprinting', is the study of extracellular metabolites and is a sub-field of metabolomics.While the same analytical approaches used for profiling metabolites apply to exometabolomics, including liquid-chromatography mass spectrometry (LC-MS), nuclear magnetic resonance (NMR) and gas chromatography–mass spectrometry (GC–MS), analysis of exometabolites provides specific challenges and is most commonly focused on investigation of the transformations of exogenous metabolite pools by biological systems. Typically, these experiments are performed by comparing metabolites at two or more time points, for example, spent vs. uninoculated/control culture media; this approach can differentiate different physiological states of wild-type yeast and between yeast mutants. Since, in many cases, the exometabolite (extracellular) pool is less dynamic than endometabolite (intracellular) pools (which are often perturbed during sample processing) and chemically defined media can be used, it reduces some of the experimental challenges of metabolomics.Exometabolomics is also used as a complementary tool with genomic, transcriptomic and proteomic data, to gain insight into the function of genes and pathways. Additionally, exometabolomics can be used to measure polar molecules being consumed or released by an organism, and to measure secondary metabolite production.
History:
The study of extracellular metabolites has been prevalent in scientific literature. However, global exometabolite profiling was only realized with recent advances allowing for improved chromatographic separation and detection of hundreds to thousands of compounds by the mid-2000s. The first work to demonstrate the biological relevance of comparative profiling of exometabolite pools was not until 2003, when the term "metabolite footprinting" was coined by Jess Allen and coworkers. This work attracted a great deal of interest in the community, particularly for characterization of microbial metabolism. The idea of the "exometabolome" encompassing the components of the exometabolite pool was not introduced until 2005.Recent advances in mass spectrometry imaging have allowed for spatial localization of released metabolites. As the field of microbiology becomes increasingly more centered on microbial community structure, exometabolomics has provided for rapid understanding of metabolic interactions between two or more species. Recently, exometabolomics has been used to design co-culture systems. Because the analysis of extracellular metabolites allows for the predictions and determinations of metabolite exchange, exometabolomics analyses can be used for understanding community ecological networks.
Analytical technologies:
In principle, any technologies used for metabolomics can be used for exometabolomics. However, liquid chromatography–mass spectrometry (LC–MS) has been the most widely used. As with typical metabolomic measurements, metabolites are identified based on accurate mass, retention time, and their MS/MS fragmentation patterns, in comparison to authentic standards. Chromatographies typically used are hydrophilic interaction liquid chromatography for the measurement of polar metabolites, or reversed-phase (C18) chromatography for the measurement of non-polar compounds, lipids, and secondary metabolites. Gas chromatography–mass spectrometry can also be used to measure sugars and other carbohydrates, and to obtain complete metabolic profiles.Because LC–MS does not give spatial data on metabolite localization, it can be complemented with mass spectrometry imaging (MSI).
Applications:
Exometabolomic techniques have been used in the following fields: Functional genomics Metabolite utilization to annotate function of unknown genes.
Bioenergy In lignocellulosic feedstock studies.
Agriculture and food Characterization of plant root exometabolites to determine how exometabolites affect Plant-growth promoting rhizobacteria.Metabolic footprinting of yeast strains for identification of yeast strains optimal for enhancing fermentation performance and positive attributes in wine.
Health Differentiating healthy versus cancerous bladder cells with metabolic footprinting.Footprinting, in combination with other techniques, for early recognition of outbreak and strain characterization.Studying aging with C. elegans exometabolomics.Extracellular metabolite analysis to evaluate pathogenic mechanism of intracellular protozoal parasite.
Analysis of carbon cycling Global carbon fixation, phytoplankton/dinoflaggelate interactions, and exometabolomics.
Microbial communities Interaction of E. coli exometabolites with C. elegans affects life span.Bacteria and yeast in dairy systems.
Applications:
Bioremediation Metabolic niche partitioning In 2010, exometabolomics analysis of the cyanobacterium, Synechococcus sp. PCC 7002 by Baran, et al. revealed that this photoautotroph could deplete a diverse pool of exogenous metabolites. A follow-up exometabolomics study on sympatric microbial isolates from biological soil crust, which exist in communities with cyanobacteria in the desert soils of the Colorado Plateau, suggested that metabolite niche partitioning exists in these communities, where each isolate only utilizes 13-26% of metabolites from the soil Secondary metabolites Metabolic footprinting for determination of antifungal substances' mode of action | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Leather conditioner**
Leather conditioner:
Conditioners used on leather take many shapes and forms. They are used mostly to keep leather from drying out and deteriorating.
A very old and widely used conditioner is dubbin. Another common conditioner is Mink oil. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Remote base station**
Remote base station:
A remote base station is a common name for an amateur radio auxiliary station that is controlled and operated from a remote location. Most remote base stations have similar features to any other Amateur radio station but can be controlled over a direct wired connection or the internet, or by radio.
In many ways, remote base stations controlled by radio, resemble repeaters with additional features. Remote base stations are usually run and maintained by individual hobbyists or clubs. Unlike repeaters, they are not usually open to all amateur radio operators. A remote base is one type of station where the primary control point is not at the station location.
Remote base station:
When using a radio link, remotely controlling an auxiliary base station consists of sending the primary signal (voice or data) along with some form of control signal, such as DTMF tones, to another station to change its operating parameters i.e. turn it on or off, change frequency or transmitter power level, rotate the antenna, etc. These signals are considered one form of primary station control, for which the station licensee, and/or a control operator are primarily responsible.
Remote base station:
References in two paragraphs following are noted in square brackets and refer to the United States FCC Regulation 97 28th Revised Edition Updated to January 2012, governing the Amateur Radio Service.
Remote base station:
In the United States, radio control link frequencies must be above 144.5 MHz. [97.201(b)] However, the base station being controlled may operate on any amateur frequency. The FCC says that if a radio link is used, the station where the control commands are performed is an auxiliary station, [97.213(a)] and an auxiliary station is "an amateur station transmitting communications point-to-point within a system of cooperating amateur stations" [97.3(a)(7)] Start of the 21st century technology has enabled ham radio operators to control remote bases via the Internet. Many people use IRLP or Echolink to remotely control their stations.
Remote base station:
Telecommand is defined by the Federal Communications Commission as a one-way transmission to initiate, modify or terminate functions of a device at a distance [97.3(a)(43)]. Control (or telecommand) links for a remote base station may be wire (telephone line, fiber optic line, Internet, etc.) or radio. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Factory reset**
Factory reset:
A factory reset, also known as hard reset or master reset, is a software restore of an electronic device to its original system state by erasing all of the data, settings, and applications that were previously stored on the device. This is often done to fix an issue with a device, but it could also be done to restore the device to its original settings.Since a factory reset entails deleting all information stored in the device, it is essentially the same concept as reformatting a hard drive. Pre-installed applications and data on the card's storage card (such as a microSD card) will not be erased.Factory resets can fix many chronic performance issues (i.e. freezing), but it does not remove the device's operating system. Factory resets may also be used to prepare a device for sale, refurbishing, destruction, donation or other transfers of ownership by removing personal data and configurations associated with the previous owner.
Examples:
Factory resets can be achieved in a variety of ways depending on the electronic device. For some devices, this could be done by going into the device's Service Menu. Other devices may require a complete re-installation of the software. The following section lists a few common electronic devices and how they can be reset to factory settings.Computer factory resets will restore the computer to the computer's original operating system and delete all of the user data stored on the computer. Microsoft's Windows 8 and Windows 10, and Apple's macOS have options for this.On Android devices, there is a factory data reset option in Settings that will appear to erase all of the device's data and reset all of its settings. This method is typically used when the device has a technical problem that cannot be fixed using other methods, or when the owner wants to remove all their personal data before selling, giving away, returning or disposing of the device. Factory Reset Protection (FRP) is a security feature implemented in Android devices starting from Android 5.1 Lollipop. Its purpose is to prevent unauthorized access to a device that has been lost, stolen, or reset to factory settings. If the user does not recall the Google account information, alternative methods such as vnROM FRP bypass are utilized to unlock the Android device. After performing a study, Avast! reported that the data is recoverable using forensics software that is fairly generic and publicly available. On Samsung smartphones, a factory reset operation does not affect the Knox Flag. As such, it does not reset the device to its original factory settings and is not a way to return the device to a state compatible with the manufacturer's warranty. Data on the SIM card and the microSD card is not erased.Many other devices can be restored to factory settings, like televisions, GPS units or tablet computers.Many electronic devices have a menu with tools and settings called the service menu, which commonly includes a tool that performs a factory reset. This tool is most common in devices with displays, such as television sets and computer monitors. These menus are usually accessed through a sequence of button presses.
Examples:
Game cartridges, particularly ones designed for Nintendo handhelds that maintain save data, may feature a factory reset option that can instantly delete all of such data from the cartridge, initiated either by selecting a particular setting in an options menu or by inputting a particular button combination during startup. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Favorskii rearrangement**
Favorskii rearrangement:
The Favorskii rearrangement is principally a rearrangement of cyclopropanones and α-halo ketones that leads to carboxylic acid derivatives. In the case of cyclic α-halo ketones, the Favorskii rearrangement constitutes a ring contraction. This rearrangement takes place in the presence of a base, sometimes hydroxide, to yield a carboxylic acid but most of the time either an alkoxide base or an amine to yield an ester or an amide, respectively. α,α'-Dihaloketones eliminate HX under the reaction conditions to give α,β-unsaturated carbonyl compounds.
History:
The reaction is named for the Russian chemist Alexei Yevgrafovich Favorskii
Reaction mechanism:
The reaction mechanism is thought to involve the formation of an enolate on the side of the ketone away from the chlorine atom. This enolate cyclizes to a cyclopropanone intermediate which is then attacked by the hydroxide nucleophile.
The second step has also been proposed to be stepwise process, with chloride anion leaving first to produce a zwitterionic oxyallyl cation before a disrotatory electrocyclic ring closure takes place to afford the cyclopropanone intermediate.Usage of alkoxide anions such as sodium methoxide, instead of sodium hydroxide, yields the ring-contracted ester product.
Reaction mechanism:
When enolate formation is impossible, the Favorskii rearrangement takes place by an alternate mechanism, in which addition to hydroxide to the ketone takes place, followed by concerted collapse of the tetrahedral intermediate and migration of the neighboring carbon with displacement of the halide. This is sometimes known as the pseudo-Favorskii rearrangement, although previous to labeling studies, it was thought that all Favorskii rearrangements proceeded through this mechanism.
Wallach degradation:
In the related Wallach degradation (Otto Wallach, 1918) not one but two halogen atoms flank the ketone resulting in a new contracted ketone after oxidation and decarboxylation
Photo-Favorskii reaction:
The reaction type also exists as a photochemical reaction. The photo-Favorskii reaction has been used in the photochemical unlocking of certain phosphates (for instance those of ATP) protected by so-called p-hydroxyphenacyl groups. The deprotection proceeds through a triplet diradical (3) and a dione spiro intermediate (4) although the latter has thus far eluded detection. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Contact mechanics**
Contact mechanics:
Contact mechanics is the study of the deformation of solids that touch each other at one or more points. A central distinction in contact mechanics is between stresses acting perpendicular to the contacting bodies' surfaces (known as normal stress) and frictional stresses acting tangentially between the surfaces (shear stress). Normal contact mechanics or frictionless contact mechanics focuses on normal stresses caused by applied normal forces and by the adhesion present on surfaces in close contact, even if they are clean and dry.
Contact mechanics:
Frictional contact mechanics emphasizes the effect of friction forces.
Contact mechanics:
Contact mechanics is part of mechanical engineering. The physical and mathematical formulation of the subject is built upon the mechanics of materials and continuum mechanics and focuses on computations involving elastic, viscoelastic, and plastic bodies in static or dynamic contact. Contact mechanics provides necessary information for the safe and energy efficient design of technical systems and for the study of tribology, contact stiffness, electrical contact resistance and indentation hardness. Principles of contacts mechanics are implemented towards applications such as locomotive wheel-rail contact, coupling devices, braking systems, tires, bearings, combustion engines, mechanical linkages, gasket seals, metalworking, metal forming, ultrasonic welding, electrical contacts, and many others. Current challenges faced in the field may include stress analysis of contact and coupling members and the influence of lubrication and material design on friction and wear. Applications of contact mechanics further extend into the micro- and nanotechnological realm.
Contact mechanics:
The original work in contact mechanics dates back to 1881 with the publication of the paper "On the contact of elastic solids" ("Ueber die Berührung fester elastischer Körper") by Heinrich Hertz. Hertz was attempting to understand how the optical properties of multiple, stacked lenses might change with the force holding them together. Hertzian contact stress refers to the localized stresses that develop as two curved surfaces come in contact and deform slightly under the imposed loads. This amount of deformation is dependent on the modulus of elasticity of the material in contact. It gives the contact stress as a function of the normal contact force, the radii of curvature of both bodies and the modulus of elasticity of both bodies. Hertzian contact stress forms the foundation for the equations for load bearing capabilities and fatigue life in bearings, gears, and any other bodies where two surfaces are in contact.
History:
Classical contact mechanics is most notably associated with Heinrich Hertz. In 1882, Hertz solved the contact problem of two elastic bodies with curved surfaces. This still-relevant classical solution provides a foundation for modern problems in contact mechanics. For example, in mechanical engineering and tribology, Hertzian contact stress is a description of the stress within mating parts. The Hertzian contact stress usually refers to the stress close to the area of contact between two spheres of different radii.
History:
It was not until nearly one hundred years later that Johnson, Kendall, and Roberts found a similar solution for the case of adhesive contact. This theory was rejected by Boris Derjaguin and co-workers who proposed a different theory of adhesion in the 1970s. The Derjaguin model came to be known as the DMT (after Derjaguin, Muller and Toporov) model, and the Johnson et al. model came to be known as the JKR (after Johnson, Kendall and Roberts) model for adhesive elastic contact. This rejection proved to be instrumental in the development of the Tabor and later Maugis parameters that quantify which contact model (of the JKR and DMT models) represent adhesive contact better for specific materials.
History:
Further advancement in the field of contact mechanics in the mid-twentieth century may be attributed to names such as Bowden and Tabor. Bowden and Tabor were the first to emphasize the importance of surface roughness for bodies in contact. Through investigation of the surface roughness, the true contact area between friction partners is found to be less than the apparent contact area. Such understanding also drastically changed the direction of undertakings in tribology. The works of Bowden and Tabor yielded several theories in contact mechanics of rough surfaces.
History:
The contributions of Archard (1957) must also be mentioned in discussion of pioneering works in this field. Archard concluded that, even for rough elastic surfaces, the contact area is approximately proportional to the normal force. Further important insights along these lines were provided by Greenwood and Williamson (1966), Bush (1975), and Persson (2002). The main findings of these works were that the true contact surface in rough materials is generally proportional to the normal force, while the parameters of individual micro-contacts (i.e., pressure, size of the micro-contact) are only weakly dependent upon the load.
Classical solutions for non-adhesive elastic contact:
The theory of contact between elastic bodies can be used to find contact areas and indentation depths for simple geometries. Some commonly used solutions are listed below. The theory used to compute these solutions is discussed later in the article. Solutions for multitude of other technically relevant shapes, e.g. the truncated cone, the worn sphere, rough profiles, hollow cylinders, etc. can be found in Contact between a sphere and a half-space An elastic sphere of radius R indents an elastic half-space where total deformation is d , causing a contact area of radius a=Rd The applied force F is related to the displacement d by F=43E∗R12d32 where 1E∗=1−ν12E1+1−ν22E2 and E1 ,E2 are the elastic moduli and ν1 ,ν2 the Poisson's ratios associated with each body.
Classical solutions for non-adhesive elastic contact:
The distribution of normal pressure in the contact area as a function of distance from the center of the circle is p(r)=p0(1−r2a2)12 where p0 is the maximum contact pressure given by p0=3F2πa2=1π(6FE∗2R2)13 The radius of the circle is related to the applied load F by the equation a3=3FR4E∗ The total deformation d is related to the maximum contact pressure by 16 E∗2R)13 The maximum shear stress occurs in the interior at 0.49 a for 0.33 Contact between two spheres For contact between two spheres of radii R1 and R2 , the area of contact is a circle of radius a . The equations are the same as for a sphere in contact with a half plane except that the effective radius R is defined as 1R=1R1+1R2 Contact between two crossed cylinders of equal radius This is equivalent to contact between a sphere of radius R and a plane.
Classical solutions for non-adhesive elastic contact:
Contact between a rigid cylinder with flat end and an elastic half-space If a rigid cylinder is pressed into an elastic half-space, it creates a pressure distribution described by p(r)=p0(1−r2R2)−12 where R is the radius of the cylinder and p0=1πE∗dR The relationship between the indentation depth and the normal force is given by F=2RE∗d Contact between a rigid conical indenter and an elastic half-space In the case of indentation of an elastic half-space of Young's modulus E using a rigid conical indenter, the depth of the contact region ϵ and contact radius a are related by tan (θ) with θ defined as the angle between the plane and the side surface of the cone. The total indentation depth d is given by: d=π2ϵ The total force is tan tan (θ) The pressure distribution is given by ln cosh −1(ar) The stress has a logarithmic singularity at the tip of the cone.
Classical solutions for non-adhesive elastic contact:
Contact between two cylinders with parallel axes In contact between two cylinders with parallel axes, the force is linearly proportional to the length of cylinders L and to the indentation depth d: F≈π4E∗Ld The radii of curvature are entirely absent from this relationship. The contact radius is described through the usual relationship a=Rd with 1R=1R1+1R2 as in contact between two spheres. The maximum pressure is equal to p0=(E∗FπLR)12 Bearing contact The contact in the case of bearings is often a contact between a convex surface (male cylinder or sphere) and a concave surface (female cylinder or sphere: bore or hemispherical cup).
Classical solutions for non-adhesive elastic contact:
The Method of Dimensionality Reduction Some contact problems can be solved with the Method of Dimensionality Reduction (MDR). In this method, the initial three-dimensional system is replaced with a contact of a body with a linear elastic or viscoelastic foundation (see fig.). The properties of one-dimensional systems coincide exactly with those of the original three-dimensional system, if the form of the bodies is modified and the elements of the foundation are defined according to the rules of the MDR. MDR is based on the solution to axisymmetric contact problems first obtained by Ludwig Föppl (1941) and Gerhard Schubert (1942)However, for exact analytical results, it is required that the contact problem is axisymmetric and the contacts are compact.
Hertzian theory of non-adhesive elastic contact:
The classical theory of contact focused primarily on non-adhesive contact where no tension force is allowed to occur within the contact area, i.e., contacting bodies can be separated without adhesion forces. Several analytical and numerical approaches have been used to solve contact problems that satisfy the no-adhesion condition. Complex forces and moments are transmitted between the bodies where they touch, so problems in contact mechanics can become quite sophisticated. In addition, the contact stresses are usually a nonlinear function of the deformation. To simplify the solution procedure, a frame of reference is usually defined in which the objects (possibly in motion relative to one another) are static. They interact through surface tractions (or pressures/stresses) at their interface.
Hertzian theory of non-adhesive elastic contact:
As an example, consider two objects which meet at some surface S in the ( x ,y )-plane with the z -axis assumed normal to the surface. One of the bodies will experience a normally-directed pressure distribution pz=p(x,y)=qz(x,y) and in-plane surface traction distributions qx=qx(x,y) and qy=qy(x,y) over the region S . In terms of a Newtonian force balance, the forces: Pz=∫Sp(x,y)dA;Qx=∫Sqx(x,y)dA;Qy=∫Sqy(x,y)dA must be equal and opposite to the forces established in the other body. The moments corresponding to these forces: Mx=∫Syqz(x,y)dA;My=∫S−xqz(x,y)dA;Mz=∫S[xqy(x,y)−yqx(x,y)]dA are also required to cancel between bodies so that they are kinematically immobile.
Hertzian theory of non-adhesive elastic contact:
Assumptions in Hertzian theory The following assumptions are made in determining the solutions of Hertzian contact problems: The strains are small and within the elastic limit.
The surfaces are continuous and non-conforming (implying that the area of contact is much smaller than the characteristic dimensions of the contacting bodies).
Each body can be considered an elastic half-space.
The surfaces are frictionless.Additional complications arise when some or all these assumptions are violated and such contact problems are usually called non-Hertzian.
Hertzian theory of non-adhesive elastic contact:
Analytical solution techniques Analytical solution methods for non-adhesive contact problem can be classified into two types based on the geometry of the area of contact. A conforming contact is one in which the two bodies touch at multiple points before any deformation takes place (i.e., they just "fit together"). A non-conforming contact is one in which the shapes of the bodies are dissimilar enough that, under zero load, they only touch at a point (or possibly along a line). In the non-conforming case, the contact area is small compared to the sizes of the objects and the stresses are highly concentrated in this area. Such a contact is called concentrated, otherwise it is called diversified.
Hertzian theory of non-adhesive elastic contact:
A common approach in linear elasticity is to superpose a number of solutions each of which corresponds to a point load acting over the area of contact. For example, in the case of loading of a half-plane, the Flamant solution is often used as a starting point and then generalized to various shapes of the area of contact. The force and moment balances between the two bodies in contact act as additional constraints to the solution.
Hertzian theory of non-adhesive elastic contact:
Point contact on a (2D) half-plane A starting point for solving contact problems is to understand the effect of a "point-load" applied to an isotropic, homogeneous, and linear elastic half-plane, shown in the figure to the right. The problem may be either plane stress or plane strain. This is a boundary value problem of linear elasticity subject to the traction boundary conditions: σxz(x,0)=0;σz(x,z)=−Pδ(x,z) where δ(x,z) is the Dirac delta function. The boundary conditions state that there are no shear stresses on the surface and a singular normal force P is applied at (0, 0). Applying these conditions to the governing equations of elasticity produces the result σxx=−2Pπx2z(x2+z2)2σzz=−2Pπz3(x2+z2)2σxz=−2Pπxz2(x2+z2)2 for some point, (x,y) , in the half-plane. The circle shown in the figure indicates a surface on which the maximum shear stress is constant. From this stress field, the strain components and thus the displacements of all material points may be determined.
Hertzian theory of non-adhesive elastic contact:
Line contact on a (2D) half-plane Normal loading over a region Suppose, rather than a point load P , a distributed load p(x) is applied to the surface instead, over the range a<x<b . The principle of linear superposition can be applied to determine the resulting stress field as the solution to the integral equations: σxx=−2zπ∫abp(x′)(x−x′)2dx′[(x−x′)2+z2]2;σzz=−2z3π∫abp(x′)dx′[(x−x′)2+z2]2σxz=−2z2π∫abp(x′)(x−x′)dx′[(x−x′)2+z2]2 Shear loading over a region The same principle applies for loading on the surface in the plane of the surface. These kinds of tractions would tend to arise as a result of friction. The solution is similar the above (for both singular loads Q and distributed loads q(x) ) but altered slightly: σxx=−2π∫abq(x′)(x−x′)3dx′[(x−x′)2+z2]2;σzz=−2z2π∫abq(x′)(x−x′)dx′[(x−x′)2+z2]2σxz=−2zπ∫abq(x′)(x−x′)2dx′[(x−x′)2+z2]2 These results may themselves be superposed onto those given above for normal loading to deal with more complex loads.
Hertzian theory of non-adhesive elastic contact:
Point contact on a (3D) half-space Analogously to the Flamant solution for the 2D half-plane, fundamental solutions are known for the linearly elastic 3D half-space as well. These were found by Boussinesq for a concentrated normal load and by Cerruti for a tangential load. See the section on this in Linear elasticity.
Hertzian theory of non-adhesive elastic contact:
Numerical solution techniques Distinctions between conforming and non-conforming contact do not have to be made when numerical solution schemes are employed to solve contact problems. These methods do not rely on further assumptions within the solution process since they base solely on the general formulation of the underlying equations. Besides the standard equations describing the deformation and motion of bodies two additional inequalities can be formulated. The first simply restricts the motion and deformation of the bodies by the assumption that no penetration can occur. Hence the gap h between two bodies can only be positive or zero h≥0 where h=0 denotes contact. The second assumption in contact mechanics is related to the fact, that no tension force is allowed to occur within the contact area (contacting bodies can be lifted up without adhesion forces). This leads to an inequality which the stresses have to obey at the contact interface. It is formulated for the normal stress σn=t⋅n At locations where there is contact between the surfaces the gap is zero, i.e. h=0 , and there the normal stress is different than zero, indeed, σn<0 . At locations where the surfaces are not in contact the normal stress is identical to zero; σn=0 , while the gap is positive; i.e., h>0 . This type of complementarity formulation can be expressed in the so-called Kuhn–Tucker form, viz.
Hertzian theory of non-adhesive elastic contact:
These conditions are valid in a general way. The mathematical formulation of the gap depends upon the kinematics of the underlying theory of the solid (e.g., linear or nonlinear solid in two- or three dimensions, beam or shell model). By restating the normal stress σn in terms of the contact pressure, p ; i.e., p=−σn the Kuhn-Tucker problem can be restated as in standard complementarity form i.e. In the linear elastic case the gap can be formulated as where h0 is the rigid body separation, g is the geometry/topography of the contact (cylinder and roughness) and u is the elastic deformation/deflection. If the contacting bodies are approximated as linear elastic half spaces, the Boussinesq-Cerruti integral equation solution can be applied to express the deformation ( u ) as a function of the contact pressure ( p ); i.e., where for line loading of an elastic half space and for point loading of an elastic half-space.After discretization the linear elastic contact mechanics problem can be stated in standard Linear Complementarity Problem (LCP) form.
Hertzian theory of non-adhesive elastic contact:
h=h0+g+Cp,h⋅p=0,p≥0,h≥0, where C is a matrix, whose elements are so called influence coefficients relating the contact pressure and the deformation. The strict LCP formulation of the CM problem presented above, allows for direct application of well-established numerical solution techniques such as Lemke's pivoting algorithm. The Lemke algorithm has the advantage that it finds the numerically exact solution within a finite number of iterations. The MATLAB implementation presented by Almqvist et al. is one example that can be employed to solve the problem numerically. In addition, an example code for an LCP solution of a 2D linear elastic contact mechanics problem has also been made public at MATLAB file exchange by Almqvist et al.
Contact between rough surfaces:
When two bodies with rough surfaces are pressed against each other, the true contact area formed between the two bodies, A , is much smaller than the apparent or nominal contact area A0 . The mechanics of contacting rough surfaces are discussed in terms of normal contact mechanics and static frictional interactions. Natural and engineering surfaces typically exhibit roughness features, known as asperities, across a broad range of length scales down to the molecular level, with surface structures exhibiting self affinity, also known as surface fractality. It is recognized that the self affine structure of surfaces is the origin of the linear scaling of true contact area with applied pressure. Assuming a model of shearing welded contacts in tribological interactions, this ubiquitously observed linearity between contact area and pressure can also be considered the origin of the linearity of the relationship between static friction and applied normal force.In contact between a "random rough" surface and an elastic half-space, the true contact area is related to the normal force F by A=κE∗h′F with h′ equal to the root mean square (also known as the quadratic mean) of the surface slope and κ≈2 . The median pressure in the true contact surface pav=FA≈12E∗h′ can be reasonably estimated as half of the effective elastic modulus E∗ multiplied with the root mean square of the surface slope h′ An overview of the GW model Greenwood and Williamson in 1966 (GW) proposed a theory of elastic contact mechanics of rough surfaces which is today the foundation of many theories in tribology (friction, adhesion, thermal and electrical conductance, wear, etc.). They considered the contact between a smooth rigid plane and a nominally flat deformable rough surface covered with round tip asperities of the same radius R. Their theory assumes that the deformation of each asperity is independent of that of its neighbours and is described by the Hertz model. The heights of asperities have a random distribution. The probability that asperity height is between z and z+dz is ϕ(z)dz . The authors calculated the number of contact spots n, the total contact area Ar and the total load P in general case. They gave those formulas in two forms: in the basic and using standardized variables. If one assumes that N asperities covers a rough surface, then the expected number of contacts is n=N∫d∞ϕ(z)dz The expected total area of contact can be calculated from the formula Aa=NπR∫d∞(z−d)ϕ(z)dz and the expected total force is given by P=43NErR∫d∞(z−d)32ϕ(z)dz where: R, radius of curvature of the microasperity, z, height of the microasperity measured from the profile line, d, close the surface, Er=(1−ν12E1+1−ν22E2)−1 , composite Young's modulus of elasticity, Ei , modulus of elasticity of the surface, νi , Poisson's surface coefficients.Greenwood and Williamson introduced standardized separation h=d/σ and standardized height distribution ϕ∗(s) whose standard deviation is equal to one. Below are presented the formulas in the standardized form.
Contact between rough surfaces:
Fn(h)=∫h∞(s−h)nϕ∗(s)dsn=ηAnF0(h)Aa=πηARσF1(h)P=43ηAErRσ32F32(h) where: d is the separation, A is the nominal contact area, η is the surface density of asperities, E∗ is the effective Young modulus.
Contact between rough surfaces:
A and P can be determined when the Fn(h) terms are calculated for the given surfaces using the convolution of the surface roughness ϕ∗(s) . Several studies have followed the suggested curve fits for Fn(h) assuming a Gaussian surface high distribution with curve fits presented by Arcoumanis et al. and Jedynak among others. It has been repeatedly observed that engineering surfaces do not demonstrate Gaussian surface height distributions e.g. Peklenik. Leighton et al. presented fits for crosshatched IC engine cylinder liner surfaces together with a process for determining the Fn(h) terms for any measured surfaces. Leighton et al. demonstrated that Gaussian fit data is not accurate for modelling any engineered surfaces and went on to demonstrate that early running of the surfaces results in a gradual transition which significantly changes the surface topography, load carrying capacity and friction.
Contact between rough surfaces:
Recently the exact approximants to Ar and P were published by Jedynak. They are given by the following rational formulas, which are approximants to the integrals Fn(h) . They are calculated for the Gaussian distribution of asperities, which have been shown to be unrealistic for engineering surface but can be assumed where friction, load carrying capacity or real contact area results are not critical to the analysis.
Contact between rough surfaces:
exp (−h22) For F1(h) the coefficients are 0.398942280401 0.159773702775 0.0389687688311 0.00364356495452 1.653807476138 1.170419428529 0.448892964428 0.0951971709160 0.00931642803836 6.383774657279 10 −6] The maximum relative error is 9.93 10 −8% For F32(h) the coefficients are 0.430019993662 0.101979509447 0.0229040629580 0.000688602924 1.671117125984 1.199586555505 0.46936532151 0.102632881122 0.010686348714 0.0000517200271 ] The maximum relative error is 1.91 10 −7% . The paper also contains the exact expressions for Fn(h) exp erfc exp (−h24)h((h2+1)K14(h24)−h2K34(h24)) where erfc(z) means the complementary error function and Kν(z) is the modified Bessel function of the second kind.
Contact between rough surfaces:
For the situation where the asperities on the two surfaces have a Gaussian height distribution and the peaks can be assumed to be spherical, the average contact pressure is sufficient to cause yield when av 1.1 0.39 σ0 where σy is the uniaxial yield stress and σ0 is the indentation hardness. Greenwood and Williamson defined a dimensionless parameter Ψ called the plasticity index that could be used to determine whether contact would be elastic or plastic.
Contact between rough surfaces:
The Greenwood-Williamson model requires knowledge of two statistically dependent quantities; the standard deviation of the surface roughness and the curvature of the asperity peaks. An alternative definition of the plasticity index has been given by Mikic. Yield occurs when the pressure is greater than the uniaxial yield stress. Since the yield stress is proportional to the indentation hardness σ0 , Mikic defined the plasticity index for elastic-plastic contact to be Ψ=E∗h′σ0>23.
Contact between rough surfaces:
In this definition Ψ represents the micro-roughness in a state of complete plasticity and only one statistical quantity, the rms slope, is needed which can be calculated from surface measurements. For Ψ<23 , the surface behaves elastically during contact.
In both the Greenwood-Williamson and Mikic models the load is assumed to be proportional to the deformed area. Hence, whether the system behaves plastically or elastically is independent of the applied normal force.
An overview of the GT model The model proposed by Greenwood and Tripp (GT), extended the GW model to contact between two rough surfaces. The GT model is widely used in the field of elastohydrodynamic analysis.
Contact between rough surfaces:
The most frequently cited equations given by the GT model are for the asperity contact area Aa=π2(ηβσ)2AF2(λ), and load carried by asperities 15 π(ηβσ)2σβE′AF52(λ), where: ηβσ , roughness parameter, A , nominal contact area, λ , Stribeck oil film parameter, first defined by Stribeck \cite{gt} as λ=h/σ ,E′ , effective elastic modulus, F2,F52(λ) , statistical functions introduced to match the assumed Gaussian distribution of asperities.Leighton et al. presented fits for crosshatched IC engine cylinder liner surfaces together with a process for determining the Fn(h) terms for any measured surfaces. Leighton et al. demonstrated that Gaussian fit data is not accurate for modelling any engineered surfaces and went on to demonstrate that early running of the surfaces results in a gradual transition which significantly changes the surface topography, load carrying capacity and friction.
Contact between rough surfaces:
The exact solutions for Aa and P are firstly presented by Jedynak. They are expressed by Fn as follows. They are calculated for the Gaussian distribution of asperities, which have been shown to be unrealistic for engineering surface but can be assumed where friction, load carrying capacity or real contact area results are not critical to the analysis.
erfc exp exp (−h24)h32((2h2+3)K34(h24)−(2h2+5)K14(h24)) where erfc(z) means the complementary error function and Kν(z) is the modified Bessel function of the second kind.
Contact between rough surfaces:
In paper one can find comprehensive review of existing approximants to F52 . New proposals give the most accurate approximants to F52 and F2 , which are reported in the literature. They are given by the following rational formulas, which are very exact approximants to integrals Fn(h) . They are calculated for the Gaussian distribution of asperities exp (−h22) For F2(h) the coefficients are 0.5 0.182536384941 0.039812283118 0.003684879001 1.960841785003 1.708677456715 0.856592986083 0.264996791567 0.049257843893 0.004640740133 ] The maximum relative error is 1.68 10 −7% For F52(h) the coefficients are 0.616634218997 0.108855827811 0.023453835635 0.000449332509 1.919948267476 1.635304362591 0.799392556572 0.240278859212 0.043178653945 0.003863334276 ] The maximum relative error is 4.98 10 −8%
Adhesive contact between elastic bodies:
When two solid surfaces are brought into close proximity, they experience attractive van der Waals forces. Bradley's van der Waals model provides a means of calculating the tensile force between two rigid spheres with perfectly smooth surfaces. The Hertzian model of contact does not consider adhesion possible. However, in the late 1960s, several contradictions were observed when the Hertz theory was compared with experiments involving contact between rubber and glass spheres.
Adhesive contact between elastic bodies:
It was observed that, though Hertz theory applied at large loads, at low loads the area of contact was larger than that predicted by Hertz theory, the area of contact had a non-zero value even when the load was removed, and there was even strong adhesion if the contacting surfaces were clean and dry.This indicated that adhesive forces were at work. The Johnson-Kendall-Roberts (JKR) model and the Derjaguin-Muller-Toporov (DMT) models were the first to incorporate adhesion into Hertzian contact.
Adhesive contact between elastic bodies:
Bradley model of rigid contact It is commonly assumed that the surface force between two atomic planes at a distance z from each other can be derived from the Lennard-Jones potential. With this assumption 16 γ3z0[(zz0)−9−(zz0)−3] where F is the force (positive in compression), 2γ is the total surface energy of both surfaces per unit area, and z0 is the equilibrium separation of the two atomic planes.
Adhesive contact between elastic bodies:
The Bradley model applied the Lennard-Jones potential to find the force of adhesion between two rigid spheres. The total force between the spheres is found to be 16 γπR3[14(zz0)−8−(zz0)−2];1R=1R1+1R2 where R1,R2 are the radii of the two spheres.
The two spheres separate completely when the pull-off force is achieved at z=z0 at which point Fa=Fc=−4γπR.
Adhesive contact between elastic bodies:
Johnson-Kendall-Roberts (JKR) model of elastic contact To incorporate the effect of adhesion in Hertzian contact, Johnson, Kendall, and Roberts formulated the JKR theory of adhesive contact using a balance between the stored elastic energy and the loss in surface energy. The JKR model considers the effect of contact pressure and adhesion only inside the area of contact. The general solution for the pressure distribution in the contact area in the JKR model is p(r)=p0(1−r2a2)12+p0′(1−r2a2)−12 Note that in the original Hertz theory, the term containing p0′ was neglected on the ground that tension could not be sustained in the contact zone. For contact between two spheres p0=2aE∗πR;p0′=−(4γE∗πa)12 where a is the radius of the area of contact, F is the applied force, 2γ is the total surface energy of both surfaces per unit contact area, Ri,Ei,νi,i=1,2 are the radii, Young's moduli, and Poisson's ratios of the two spheres, and 1R=1R1+1R2;1E∗=1−ν12E1+1−ν22E2 The approach distance between the two spheres is given by d=πa2E∗(p0+2p0′)=a2R The Hertz equation for the area of contact between two spheres, modified to take into account the surface energy, has the form 12 γπRF+(6γπR)2) When the surface energy is zero, γ=0 , the Hertz equation for contact between two spheres is recovered. When the applied load is zero, the contact radius is a3=9R2γπE∗ The tensile load at which the spheres are separated (i.e., a=0 ) is predicted to be Fc=−3γπR This force is also called the pull-off force. Note that this force is independent of the moduli of the two spheres. However, there is another possible solution for the value of a at this load. This is the critical contact area ac , given by ac3=9R2γπ4E∗ If we define the work of adhesion as 12 where γ1,γ2 are the adhesive energies of the two surfaces and 12 is an interaction term, we can write the JKR contact radius as a3=3R4E∗(F+3ΔγπR+6ΔγπRF+(3ΔγπR)2) The tensile load at separation is F=−32ΔγπR and the critical contact radius is given by ac3=9R2Δγπ8E∗ The critical depth of penetration is dc=ac2R=(R129Δγπ4E∗)23 Derjaguin-Muller-Toporov (DMT) model of elastic contact The Derjaguin-Muller-Toporov (DMT) model is an alternative model for adhesive contact which assumes that the contact profile remains the same as in Hertzian contact but with additional attractive interactions outside the area of contact.
Adhesive contact between elastic bodies:
The radius of contact between two spheres from DMT theory is a3=3R4E∗(F+4γπR) and the pull-off force is Fc=−4γπR When the pull-off force is achieved the contact area becomes zero and there is no singularity in the contact stresses at the edge of the contact area.
Adhesive contact between elastic bodies:
In terms of the work of adhesion Δγ a3=3R4E∗(F+2ΔγπR) and Fc=−2ΔγπR Tabor parameter In 1977, Tabor showed that the apparent contradiction between the JKR and DMT theories could be resolved by noting that the two theories were the extreme limits of a single theory parametrized by the Tabor parameter ( μ ) defined as := dcz0≈[R(Δγ)2E∗2z03]13 where z0 is the equilibrium separation between the two surfaces in contact. The JKR theory applies to large, compliant spheres for which μ is large. The DMT theory applies for small, stiff spheres with small values of μ Subsequently, Derjaguin and his collaborators by applying Bradley's surface force law to an elastic half space, confirmed that as the Tabor parameter increases, the pull-off force falls from the Bradley value 2πRΔγ to the JKR value (3/2)πRΔγ . More detailed calculations were later done by Greenwood revealing the S-shaped load/approach curve which explains the jumping-on effect. A more efficient method of doing the calculations and additional results were given by Feng Maugis-Dugdale model of elastic contact Further improvement to the Tabor idea was provided by Maugis who represented the surface force in terms of a Dugdale cohesive zone approximation such that the work of adhesion is given by Δγ=σ0h0 where σ0 is the maximum force predicted by the Lennard-Jones potential and h0 is the maximum separation obtained by matching the areas under the Dugdale and Lennard-Jones curves (see adjacent figure). This means that the attractive force is constant for z0≤z≤z0+h0 . There is not further penetration in compression. Perfect contact occurs in an area of radius a and adhesive forces of magnitude σ0 extend to an area of radius c>a . In the region a<r<c , the two surfaces are separated by a distance h(r) with h(a)=0 and h(c)=h0 . The ratio m is defined as := ca .In the Maugis-Dugdale theory, the surface traction distribution is divided into two parts - one due to the Hertz contact pressure and the other from the Dugdale adhesive stress. Hertz contact is assumed in the region −a<r<a . The contribution to the surface traction from the Hertz pressure is given by pH(r)=(3FH2πa2)(1−r2a2)12 where the Hertz contact force FH is given by FH=4E∗a33R The penetration due to elastic compression is dH=a2R The vertical displacement at r=c is sin −1(1m)+a2m2−1] and the separation between the two surfaces at r=c is hH(c)=c22R−dH+uH(c) The surface traction distribution due to the adhesive Dugdale stress is cos for for a≤r≤c The total adhesive force is then given by cos −1(1m)+1m2m2−1] The compression due to Dugdale adhesion is dD=−(2σ0aE∗)m2−1 and the gap at r=c is cos −1(1m)+1−m] The net traction on the contact area is then given by p(r)=pH(r)+pD(r) and the net contact force is F=FH+FD . When h(c)=hH(c)+hD(c)=h0 the adhesive traction drops to zero.
Adhesive contact between elastic bodies:
Non-dimensionalized values of a,c,F,d are introduced at this stage that are defied as := := := := πc2;F¯=FπΔγR In addition, Maugis proposed a parameter λ which is equivalent to the Tabor parameter μ . This parameter is defined as := 1.16 μ where the step cohesive stress σ0 equals to the theoretical stress of the Lennard-Jones potential th 16 Δγ93z0 Zheng and Yu suggested another value for the step cohesive stress exp 223 420 0.588 Δγz0 to match the Lennard-Jones potential, which leads to 0.663 μ Then the net contact force may be expressed as sec −1m] and the elastic compression as d¯=a¯2−43λa¯m2−1 The equation for the cohesive gap between the two bodies takes the form sec sec −1m−m+1]=1 This equation can be solved to obtain values of c for various values of a and λ . For large values of λ , m→1 and the JKR model is obtained. For small values of λ the DMT model is retrieved.
Adhesive contact between elastic bodies:
Carpick-Ogletree-Salmeron (COS) model The Maugis-Dugdale model can only be solved iteratively if the value of λ is not known a-priori. The Carpick-Ogletree-Salmeron approximate solution simplifies the process by using the following relation to determine the contact radius a :a=a0(β)(β+1−F/Fc(β)1+β)23 where a0 is the contact area at zero load, and β is a transition parameter that is related to λ by 0.924 ln 1.02 β) The case β=1 corresponds exactly to JKR theory while β=0 corresponds to DMT theory. For intermediate cases 0<β<1 the COS model corresponds closely to the Maugis-Dugdale solution for 0.1 <λ<5 Influence of contact shape Even in the presence of perfectly smooth surfaces, geometry can come into play in form of the macroscopic shape of the contacting region. When a rigid punch with flat but oddly shaped face is carefully pulled off its soft counterpart, its detachment occurs not instantaneously but detachment fronts start at pointed corners and travel inwards, until the final configuration is reached which for macroscopically isotropic shapes is almost circular. The main parameter determining the adhesive strength of flat contacts occurs to be the maximum linear size of the contact. The process of detachment can as observed experimentally can be seen in the film. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Swayback**
Swayback:
Swayback, also known clinically as lordosis, refers to abnormal bent-back postures in humans and in quadrupeds, especially horses. Extreme lordosis can cause physical damage to the spinal cord and associated ligaments and tendons which can lead to severe pain. Moderate lordosis does not generally impact a horse’s usefulness and does not necessarily cause lameness.
Humans:
Swayback posture in humans is characterised by the posterior displacement of the rib cage in comparison to the pelvis. It looks like the person has a hyperextension of the lower back, however this is not necessarily the case. Most sway-back exhibits a posteriorly tilted pelvis; the lumbar region is usually flat (too flexed) and not hyperlordotic (too extended).
Horses:
Usually called "swayback", soft back, or low back, an excessive downward bend in the back is an undesirable conformation trait. Swayback is caused in part from a loss of muscle tone in both the back and abdominal muscles, plus a weakening and stretching of the ligaments. As in humans, it may be influenced by bearing young; it is sometimes seen in a broodmare that has had multiple foals. However, it is also common in older horses whose age leads to loss of muscle tone and stretched ligaments. It also occurs due to overuse or injury to the muscles and ligaments from excess work or loads, or from premature work placed upon an immature animal. Equines with too long a back are more prone to the condition than those with a short back, but as a longer back is also linked to smoother gaits, the trait is sometimes encouraged by selective breeding. It has been found to have a hereditary basis in the American Saddlebred breed, transmitted via a recessive gene. Research into the genetics underlying the condition has several values beyond just the Saddlebred breed as it may "serve as a model for investigating congenital skeletal deformities in horses and other species." | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Collagen, type IX, alpha 2**
Collagen, type IX, alpha 2:
Collagen alpha-2(IX) chain is a protein that in humans is encoded by the COL9A2 gene.This gene encodes one of the three alpha chains of type IX collagen, the major collagen component of hyaline cartilage. Type IX collagen, a heterotrimeric molecule, is usually found in tissues containing type II collagen, a fibrillar collagen. This chain is unusual in that, unlike the other two type IX alpha chains, it contains a covalently attached glycosaminoglycan side chain. Mutations in this gene are associated with multiple epiphyseal dysplasia. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Lower oceanic crust**
Lower oceanic crust:
The lower oceanic crust is the lower part of the oceanic crust and represents the major part of it (volumetrically biggest part). It is generally located 4–8 km below the ocean floor and the major lithologies are mafic (ultramafic and gabbroic rocks) which derive from melts rising from the earth's mantle. This part of the oceanic crust is an important zone for processes such as melt accumulation and melt modification (fractional crystallisation and crustal assimilation). And the recycling of this part of the oceanic crust, together with the upper mantle has been suggested as a significant source component for tholeiitic magmas in Hawaiian volcanoes. Although the lower oceanic crust builds the link between the mantle and the MORB, and can't be neglected for the understanding of MORB evolution, the complex processes operating in this zone remain unclear and there is an ongoing debate in Earth Sciences about this. It is 6KM long.
Processes:
The lower oceanic crust connects the earth's mantle with the MORB, where around 60% of the total magma production of the Earth happens. The three main processes happening in this region of the oceanic crust are partial melting of the earth's mantle, melt accumulation at various depths and the chemical modification of this melts during ascent,. This three processes do not happen in a strict order but occur all simultaneously over a depth range of 4–18 km suggesting that these processes can occur already in the upper mantle. The mantle melts are most commonly modified by fractional crystallisation due to cooling and by assimilation of crustal rocks.
Spreading rates:
The most important parameter controlling the processes operating in the lower oceanic crust is the magma supply, this is further controlled by the spreading rate, and therefore, spreading rate is a critical variable in models for the formation of the lower oceanic crust. The rate at which plate divergence occurs at mid-ocean ridges is not the same for all ridge segments. Ridges with a spreading rate less than 3 cm/a are considered slow-spreading ridges, while those with a rate greater than 5 cm/a are considered fast-spreading ridges Fast-spreading ridges Intensive search spanning over three decades of seismic imaging have shown that the ridge axis is underlain by a crystal mush containing a small percentage of melt, capped by a thin melt lens containing a generally high, but variable melt fraction. The completely liquid body is a thin and narrow sill-like lens (10 to 150 m [33 to 492 ft] thick and < 2 km [1.2 mi] wide). The lens is maintained by reinjection of primitive magma. The lack of any detectable large magma chamber and the common detection of small lens/mush zone at fast-spreading ridges emphasize the small magma chamber model.
Spreading rates:
Modally and compositionally layered gabbroic rock is often found (or abundant) in the lower crustal sections of ophiolite. The layered lower crust is thus one of the key features of all models of fast-spreading lower crust. Nevertheless, distinct modal layering as observed in major ophiolites has rarely been observed or sampled on the ocean floor. The IODP expedition 345 was one of the first drilling project, which sampled a significant thickness of layered igneous rocks. A shallow melt can erupt through cool crust and produce sheeted dikes and volcanics, but the small chamber seems difficult to resolve with traditional ideas of fractional crystallization and crystal settling to form the thick sequence of layered gabbros and foliated gabbros and ultramafics. One proposed model is the so-called "gabbro glacier", where crystals settle in a shallow melt-dominated lens beneath the ridge axis. The weight of the accumulating crystals settling to the bottom of the magma lens induces a ductile flow and deformation within the gabbros, just like the ice in a glacier responds to accumulated snow. Nevertheless, the model fails to explain the layered variations in mineral types, the correlated layering in mineral compositional variations, and the apparently primary near-vertical fabrics in the upper gabbros that appear to represent subvertical melt conduits. Kelemen and co-workers concluded that most of the lower oceanic crust crystallized in place, and proposed "the sheeted sill" model. In the model the sills form when porous flow of rising basaltic liquids (or small melt-filled fractures) are stopped beneath permeability (earth sciences) barriers of earlier crystallized melts and pond to form the sills. Cooling rates are generally sufficiently slow that crystals and their interstitial liquids are in chemical equilibrium, as long as the liquid is immobile. However, buoyancy and/or compaction (geology) may induce liquid migration through the mush, resulting a significant compositional and microstructural modification.
Spreading rates:
Slow-spreading ridges Slow- and intermediate-spreading ridges form typically valleys about 30 to 50 km (19 to 31 mi) wide and 1 to 5 km (0.62 to 3.11 mi) deep, with step-like inward-facing scarps, similar to rift valleys on land. Compared to fast spreading-ridges, the magma supply and therefore the heat flow is low and can't maintain a persistent liquid magma chamber. Sinton and Detrick (1992) modelled a schematic cross section of an axial magma chamber beneath a slow-spreading ridge such as the Mid-Atlantic Ridge. Due to the reduced heat and magma supply, a steady-state eruptible magma lens is relinquished in favor of a sill-like mush zone and a smaller transition zone beneath the well-developed rift valley. Convection and mixing in the magma chamber is far less likely than at fast ridges. Thermal constrains led to the development of different models to reconstruct the accretion history. The "infinite leek" model suggests small magma batches, forming small "nested" intrusions. Another model proposed that crystallization could occur at depth, where temperatures are higher, the formed cumulates are then "dragged" up by mantle flow to form the lower oceanic crust. Today, a model intermediate between these two has become popular. This model is referred to as a "plum pudding", where the lower oceanic crust is constructed from a number of nested plutons that crystallize within the mantle or crust. Schwartz et al. (2005) describes another variant. He postulates that the lower crust is constructed both from the nested shallow-level plutons and from the products of deeper-seated crystallization | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Vesmír**
Vesmír:
Vesmír is a Czech science magazine that has been published since 1871. As of 2012, it is produced by the Czech Academy of Sciences and published by Academia. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Checksum**
Checksum:
A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify data integrity but are not relied upon to verify data authenticity.The procedure which generates this checksum is called a checksum function or checksum algorithm. Depending on its design goals, a good checksum algorithm usually outputs a significantly different value, even for small changes made to the input. This is especially true of cryptographic hash functions, which may be used to detect many data corruption errors and verify overall data integrity; if the computed checksum for the current data input matches the stored value of a previously computed checksum, there is a very high probability the data has not been accidentally altered or corrupted.
Checksum:
Checksum functions are related to hash functions, fingerprints, randomization functions, and cryptographic hash functions. However, each of those concepts has different applications and therefore different design goals. For instance, a function returning the start of a string can provide a hash appropriate for some applications but will never be a suitable checksum. Checksums are used as cryptographic primitives in larger authentication algorithms. For cryptographic systems with these two specific design goals, see HMAC.
Checksum:
Check digits and parity bits are special cases of checksums, appropriate for small blocks of data (such as Social Security numbers, bank account numbers, computer words, single bytes, etc.). Some error-correcting codes are based on special checksums which not only detect common errors but also allow the original data to be recovered in certain cases.
Algorithms:
Parity byte or parity word The simplest checksum algorithm is the so-called longitudinal parity check, which breaks the data into "words" with a fixed number n of bits, and then computes the bitwise exclusive or (XOR) of all those words. The result is appended to the message as an extra word. In simpler terms, for n=1 this means adding a bit to the end of the data bits to guarantee that there is an even number of '1's. To check the integrity of a message, the receiver computes the bitwise exclusive or of all its words, including the checksum; if the result is not a word consisting of n zeros, the receiver knows a transmission error occurred.With this checksum, any transmission error which flips a single bit of the message, or an odd number of bits, will be detected as an incorrect checksum. However, an error that affects two bits will not be detected if those bits lie at the same position in two distinct words. Also swapping of two or more words will not be detected. If the affected bits are independently chosen at random, the probability of a two-bit error being undetected is 1/n.
Algorithms:
Sum complement A variant of the previous algorithm is to add all the "words" as unsigned binary numbers, discarding any overflow bits, and append the two's complement of the total as the checksum. To validate a message, the receiver adds all the words in the same manner, including the checksum; if the result is not a word full of zeros, an error must have occurred. This variant, too, detects any single-bit error, but the pro modular sum is used in SAE J1708.
Algorithms:
Position-dependent The simple checksums described above fail to detect some common errors which affect many bits at once, such as changing the order of data words, or inserting or deleting words with all bits set to zero. The checksum algorithms most used in practice, such as Fletcher's checksum, Adler-32, and cyclic redundancy checks (CRCs), address these weaknesses by considering not only the value of each word but also its position in the sequence. This feature generally increases the cost of computing the checksum.
Algorithms:
Fuzzy checksum The idea of fuzzy checksum was developed for detection of email spam by building up cooperative databases from multiple ISPs of email suspected to be spam. The content of such spam may often vary in its details, which would render normal checksumming ineffective. By contrast, a "fuzzy checksum" reduces the body text to its characteristic minimum, then generates a checksum in the usual manner. This greatly increases the chances of slightly different spam emails producing the same checksum. The ISP spam detection software, such as SpamAssassin, of co-operating ISPs, submits checksums of all emails to the centralised service such as DCC. If the count of a submitted fuzzy checksum exceeds a certain threshold, the database notes that this probably indicates spam. ISP service users similarly generate a fuzzy checksum on each of their emails and request the service for a spam likelihood.
Algorithms:
General considerations A message that is m bits long can be viewed as a corner of the m-dimensional hypercube. The effect of a checksum algorithm that yields an n-bit checksum is to map each m-bit message to a corner of a larger hypercube, with dimension m + n. The 2m + n corners of this hypercube represent all possible received messages. The valid received messages (those that have the correct checksum) comprise a smaller set, with only 2m corners.
Algorithms:
A single-bit transmission error then corresponds to a displacement from a valid corner (the correct message and checksum) to one of the m adjacent corners. An error which affects k bits moves the message to a corner which is k steps removed from its correct corner. The goal of a good checksum algorithm is to spread the valid corners as far from each other as possible, to increase the likelihood "typical" transmission errors will end up in an invalid corner. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Horizontal situation indicator**
Horizontal situation indicator:
The horizontal situation indicator (commonly called the HSI) is an aircraft flight instrument normally mounted below the artificial horizon in place of a conventional heading indicator. It combines a heading indicator with a VHF omnidirectional range-instrument landing system (VOR-ILS) display. This reduces pilot workload by lessening the number of elements in the pilot's instrument scan to the six basic flight instruments. Among other advantages, the HSI offers freedom from the confusion of reverse sensing on an instrument landing system localizer back course approach. As long as the needle is set to the localizer front course, the instrument will indicate whether to fly left or right, in either direction of travel. On the HSI, the aircraft is represented by a schematic figure in the centre of the instrument – the VOR-ILS display is shown in relation to this figure. The heading indicator is usually slaved to a remote compass and the HSI is frequently interconnected with an autopilot capable of following the heading select bug and of executing an ILS approach by following the localizer and glide slope.On a conventional VOR indicator, left–right and to–from must be interpreted in the context of the selected course. When an HSI is tuned to a VOR station, left and right always mean left and right and TO/FROM is indicated by a simple triangular arrowhead pointing to the VOR. If the arrowhead points to the same side as the course selector arrow, it means TO, and if it points behind to the side opposite the course selector, it means FROM. The HSI illustrated here is a type designed for smaller airplanes and is the size of a standard 3 ¼-inch instrument. Airline and jet aircraft HSIs are larger and may include more display elements.
Horizontal situation indicator:
The most modern HSI displays are electronic and often integrated with electronic flight instrument systems into so-called "glass cockpit" systems.
Horizontal situation indicator:
HSI is part of a remote indicating compass system, which was developed to compensate for the errors and limitations of the older type of heading indicators. The two panel-mounted components of a typical system include the HSI and a slaving control and compensator unit, which pilots can set to auto-correct the gyro error using readings from a remotely mounted magnetic slaving transmitter when the system is set to "slave gyro" mode. In a "free gyro" mode, pilots have to manually adjust their HSI. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Xerox Character Code Standard**
Xerox Character Code Standard:
The Xerox Character Code Standard (XCCS) is a historical 16-bit character encoding that was created by Xerox in 1980 for the exchange of information between elements of the Xerox Network Systems Architecture. It encodes the characters required for languages using the Latin, Arabic, Hebrew, Greek and Cyrillic scripts, the Chinese, Japanese and Korean writing systems, and technical symbols.It can be viewed as an early precursor of, and inspiration for, the Unicode Standard.The International Character Set (ICS) is compatible with XCCS.The XCCS 2.0 (1990) revision covers Latin, Arabic, Hebrew, Gothic, Armenian, Runic, Georgian, Greek, Cyrillic, Hiragana, Katakana, Bopomofo scripts, technical, and mathematical symbols.
Code charts:
Character sets overview Character set 0x00 Character set 0x21 Character set 0x22 Character set 0x23 Character set 0x24 Character set 0x25 Character set 0x26 Character set 0x27 Character set 0x28 Character set 0x30 Character set 0x31 Character set 0xE0 Character set 0xE1 Character set 0xE2 Character set 0xE3 Character set 0xEE Character set 0xEF Character set 0xF0 Character set 0xF1 | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Fischer group Fi22**
Fischer group Fi22:
In the area of modern algebra known as group theory, the Fischer group Fi22 is a sporadic simple group of order 217 · 39 · 52 · 7 · 11 · 13 = 64561751654400 ≈ 6×1013.
History:
Fi22 is one of the 26 sporadic groups and is the smallest of the three Fischer groups. It was introduced by Bernd Fischer (1971, 1976) while investigating 3-transposition groups.
The outer automorphism group has order 2, and the Schur multiplier has order 6.
Representations:
The Fischer group Fi22 has a rank 3 action on a graph of 3510 vertices corresponding to its 3-transpositions, with point stabilizer the double cover of the group PSU6(2). It also has two rank 3 actions on 14080 points, exchanged by an outer automorphism.
Fi22 has an irreducible real representation of dimension 78. Reducing an integral form of this mod 3 gives a representation of Fi22 over the field with 3 elements, whose quotient by the 1-dimensional space of fixed vectors is a 77-dimensional irreducible representation.
The perfect triple cover of Fi22 has an irreducible representation of dimension 27 over the field with 4 elements. This arises from the fact that Fi22 is a subgroup of 2E6(22).
All the ordinary and modular character tables of Fi22 have been computed. Hiss & White (1994) found the 5-modular character table, and Noeske (2007) found the 2- and 3-modular character tables.
The automorphism group of Fi22 centralizes an element of order 3 in the baby monster group.
Generalized Monstrous Moonshine:
Conway and Norton suggested in their 1979 paper that monstrous moonshine is not limited to the monster, but that similar phenomena may be found for other groups. Larissa Queen and others subsequently found that one can construct the expansions of many Hauptmoduln from simple combinations of dimensions of sporadic groups. For Fi22, the McKay-Thompson series is T6A(τ) where one can set a(0) = 10 (OEIS: A007254), 10 10 79 352 1431 4160 13015 q5+… and η(τ) is the Dedekind eta function.
Maximal subgroups:
Wilson (1984) found the 12 conjugacy classes of maximal subgroups of Fi22 as follows: 2·U6(2) O7(3) (Two classes, fused by an outer automorphism) O+8(2):S3 210:M22 26:S6(2) (2 × 21+8):(U4(2):2) U4(3):2 × S3 2F4(2)' (This is the Tits group) 25+8:(S3 × A6) 31+6:23+4:32:2 S10 (Two classes, fused by an outer automorphism) M12 | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Hagedorn temperature**
Hagedorn temperature:
The Hagedorn temperature, TH, is the temperature in theoretical physics where hadronic matter (i.e. ordinary matter) is no longer stable, and must either "evaporate" or convert into quark matter; as such, it can be thought of as the "boiling point" of hadronic matter. It was discovered by Rolf Hagedorn. The Hagedorn temperature exists because the amount of energy available is high enough that matter particle (quark–antiquark) pairs can be spontaneously pulled from vacuum. Thus, naively considered, a system at Hagedorn temperature can accommodate as much energy as one can put in, because the formed quarks provide new degrees of freedom, and thus the Hagedorn temperature would be an impassable absolute hot. However, if this phase is viewed as quarks instead, it becomes apparent that the matter has transformed into quark matter, which can be further heated.
Hagedorn temperature:
The Hagedorn temperature, TH, is about 150 MeV/kB or about 1.7×1012 K, little above the mass–energy of the lightest hadrons, the pion. Matter at Hagedorn temperature or above will spew out fireballs of new particles, which can again produce new fireballs, and the ejected particles can then be detected by particle detectors. This quark matter has been detected in heavy-ion collisions at SPS and LHC in CERN (France and Switzerland) and at RHIC in Brookhaven National Laboratory (USA).
Hagedorn temperature:
In string theory, a separate Hagedorn temperature can be defined for strings rather than hadrons. This temperature is extremely high (1030 K) and thus of mainly theoretical interest.
History:
The Hagedorn temperature was discovered by German physicist Rolf Hagedorn in the 1960s while working at CERN. His work on the statistical bootstrap model of hadron production showed that because increases in energy in a system will cause new particles to be produced, an increase of collision energy will increase the entropy of the system rather than the temperature, and "the temperature becomes stuck at a limiting value".
Technical explanation:
Hagedorn temperature is the temperature TH above which the partition sum diverges in a system with exponential growth in the density of states.
Technical explanation:
lim Tr [e−βH]=∞ Because of the divergence, people may come to the incorrect conclusion that it is impossible to have temperatures above the Hagedorn temperature, which would make it the absolute hot temperature, because it would require an infinite amount of energy. In equations: lim lim Tr Tr [e−βH]=∞ This line of reasoning was well known to be false even to Hagedorn. The partition function for creation of hydrogen–antihydrogen pairs diverges even more rapidly, because it gets a finite contribution from energy levels that accumulate at the ionization energy. The states that cause the divergence are spatially big, since the electrons are very far from the protons. The divergence indicates that at a low temperature hydrogen–antihydrogen will not be produced, rather proton/antiproton and electron/antielectron. The Hagedorn temperature is only a maximum temperature in the physically unrealistic case of exponentially many species with energy E and finite size.
Technical explanation:
The concept of exponential growth in the number of states was originally proposed in the context of condensed matter physics. It was incorporated into high-energy physics in the early 1970s by Steven Frautschi and Hagedorn. In hadronic physics, the Hagedorn temperature is the deconfinement temperature.
In string theory:
In string theory, it indicates a phase transition: the transition at which very long strings are copiously produced. It is controlled by the size of the string tension, which is smaller than the Planck scale by some power of the coupling constant. By adjusting the tension to be small compared to the Planck scale, the Hagedorn transition can be much less than the Planck temperature. Traditional grand unified string models place this in the magnitude of 1030 kelvin, two orders of magnitude smaller than the Planck temperature. Such temperatures have not been reached in any experiment and are far beyond the reach of current, or even foreseeable technology. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Mean curvature flow**
Mean curvature flow:
In the field of differential geometry in mathematics, mean curvature flow is an example of a geometric flow of hypersurfaces in a Riemannian manifold (for example, smooth surfaces in 3-dimensional Euclidean space). Intuitively, a family of surfaces evolves under mean curvature flow if the normal component of the velocity of which a point on the surface moves is given by the mean curvature of the surface. For example, a round sphere evolves under mean curvature flow by shrinking inward uniformly (since the mean curvature vector of a sphere points inward). Except in special cases, the mean curvature flow develops singularities.
Mean curvature flow:
Under the constraint that volume enclosed is constant, this is called surface tension flow.
It is a parabolic partial differential equation, and can be interpreted as "smoothing".
Existence and uniqueness:
The following was shown by Michael Gage and Richard S. Hamilton as an application of Hamilton's general existence theorem for parabolic geometric flows.Let M be a compact smooth manifold, let (M′,g) be a complete smooth Riemannian manifold, and let f:M→M′ be a smooth immersion. Then there is a positive number T , which could be infinite, and a map F:[0,T)×M→M′ with the following properties: F(0,⋅)=f F(t,⋅):M→M′ is a smooth immersion for any t∈[0,T) as t↘0, one has F(t,⋅)→f in C∞ for any (t0,p)∈(0,T)×M , the derivative of the curve t↦F(t,p) at t0 is equal to the mean curvature vector of F(t0,⋅) at p if F~:[0,T~)×M→M′ is any other map with the four properties above, then T~≤T and F~(t,p)=F(t,p) for any (t,p)∈[0,T~)×M.
Existence and uniqueness:
Necessarily, the restriction of F to (0,T)×M is C∞ One refers to F as the (maximally extended) mean curvature flow with initial data f
Convergence theorems:
Following Hamilton's epochal 1982 work on the Ricci flow, in 1984 Gerhard Huisken employed the same methods for the mean curvature flow to produce the following analogous result: If (M′,g) is the Euclidean space Rn+1 , where n≥2 denotes the dimension of M , then T is necessarily finite. If the second fundamental form of the 'initial immersion' f is strictly positive, then the second fundamental form of the immersion F(t,⋅) is also strictly positive for every t∈(0,T) , and furthermore if one choose the function c:(0,T)→(0,∞) such that the volume of the Riemannian manifold Euc ) is independent of t , then as t↗T the immersions c(t)F(t,⋅):M→Rn+1 smoothly converge to an immersion whose image in Rn+1 is a round sphere.Note that if n≥2 and f:M→Rn+1 is a smooth hypersurface immersion whose second fundamental form is positive, then the Gauss map ν:M→Sn is a diffeomorphism, and so one knows from the start that M is diffeomorphic to Sn and, from elementary differential topology, that all immersions considered above are embeddings.
Convergence theorems:
Gage and Hamilton extended Huisken's result to the case n=1 . Matthew Grayson (1987) showed that if f:S1→R2 is any smooth embedding, then the mean curvature flow with initial data f eventually consists exclusively of embeddings with strictly positive curvature, at which point Gage and Hamilton's result applies. In summary: If f:S1→R2 is a smooth embedding, then consider the mean curvature flow F:[0,T)×S1→R2 with initial data f . Then F(t,⋅):S1→R2 is a smooth embedding for every t∈(0,T) and there exists t0∈(0,T) such that F(t,⋅):S1→R2 has positive (extrinsic) curvature for every t∈(t0,T) . If one selects the function c as in Huisken's result, then as t↗T the embeddings c(t)F(t,⋅):S1→R2 converge smoothly to an embedding whose image is a round circle.
Properties:
The mean curvature flow extremalizes surface area, and minimal surfaces are the critical points for the mean curvature flow; minima solve the isoperimetric problem.
For manifolds embedded in a Kähler–Einstein manifold, if the surface is a Lagrangian submanifold, the mean curvature flow is of Lagrangian type, so the surface evolves within the class of Lagrangian submanifolds.
Huisken's monotonicity formula gives a monotonicity property of the convolution of a time-reversed heat kernel with a surface undergoing the mean curvature flow.
Related flows are: Curve-shortening flow, the one-dimensional case of mean curvature flow the surface tension flow the Lagrangian mean curvature flow the inverse mean curvature flow
Mean curvature flow of a three-dimensional surface:
The differential equation for mean-curvature flow of a surface given by z=S(x,y) is given by ∂S∂t=2DH(x,y)1+(∂S∂x)2+(∂S∂y)2 with D being a constant relating the curvature and the speed of the surface normal, and the mean curvature being H(x,y)=12(1+(∂S∂x)2)∂2S∂y2−2∂S∂x∂S∂y∂2S∂x∂y+(1+(∂S∂y)2)∂2S∂x2(1+(∂S∂x)2+(∂S∂y)2)3/2.
Mean curvature flow of a three-dimensional surface:
In the limits |∂S∂x|≪1 and |∂S∂y|≪1 , so that the surface is nearly planar with its normal nearly parallel to the z axis, this reduces to a diffusion equation ∂S∂t=D∇2S While the conventional diffusion equation is a linear parabolic partial differential equation and does not develop singularities (when run forward in time), mean curvature flow may develop singularities because it is a nonlinear parabolic equation. In general additional constraints need to be put on a surface to prevent singularities under mean curvature flows.
Mean curvature flow of a three-dimensional surface:
Every smooth convex surface collapses to a point under the mean-curvature flow, without other singularities, and converges to the shape of a sphere as it does so. For surfaces of dimension two or more this is a theorem of Gerhard Huisken; for the one-dimensional curve-shortening flow it is the Gage–Hamilton–Grayson theorem. However, there exist embedded surfaces of two or more dimensions other than the sphere that stay self-similar as they contract to a point under the mean-curvature flow, including the Angenent torus.
Example: mean curvature flow of m-dimensional spheres:
A simple example of mean curvature flow is given by a family of concentric round hyperspheres in Rm+1 . The mean curvature of an m -dimensional sphere of radius R is H=m/R Due to the rotational symmetry of the sphere (or in general, due to the invariance of mean curvature under isometries) the mean curvature flow equation ∂tF=−Hν reduces to the ordinary differential equation, for an initial sphere of radius R0 ,ddtR(t)=−mR(t),R(0)=R0.
Example: mean curvature flow of m-dimensional spheres:
The solution of this ODE (obtained, e.g., by separation of variables) is R(t)=R02−2mt ,which exists for t∈(−∞,R02/2m) | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Gastrointestinal neuroectodermal tumor**
Gastrointestinal neuroectodermal tumor:
A gastrointestinal neuroectodermal tumor is a neuroectodermal tumor that appears in the gastrointestinal system. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**UQCRC2**
UQCRC2:
Cytochrome b-c1 complex subunit 2, mitochondrial (UQCRC2), also known as QCR2, UQCR2, or MC3DN5 is a protein that in humans is encoded by the UQCRC2 gene. The product of UQCRC2 is a subunit of the respiratory chain protein Ubiquinol Cytochrome c Reductase (UQCR, Complex III or Cytochrome bc1 complex), which consists of the products of one mitochondrially encoded gene, MTCYTB (mitochondrial cytochrome b) and ten nuclear genes: UQCRC1, UQCRC2, Cytochrome c1, UQCRFS1 (Rieske protein), UQCRB, "11kDa protein", UQCRH (cyt c1 Hinge protein), Rieske Protein presequence, "cyt. c1 associated protein", and "Rieske-associated protein." Defects in UQCRC2 are associated with mitochondrial complex III deficiency, nuclear, type 5.
Structure:
UQCRC2 is located on the p arm of chromosome 16 in position 12.2 and has 14 exons. The UQCRC2 gene produces a 48.4 kDa protein composed of 453 amino acids. UQCRC2 belongs to the peptidase M16 family and UQCRC2/QCR2 subfamily. UQCRC2 has a transit peptide domain. Ubiquinol Cytochrome c Reductase (b-c1 complex) contains 11 subunits: 3 respiratory subunits (cytochrome b, cytochrome c1 and Rieske/UQCRFS1), 2 core proteins (UQCRC1/QCR1 and UQCRC2/QCR2) and 6 low-molecular weight proteins (UQCRH/QCR6, UQCRB/QCR7, UQCRQ/QCR8, UQCR10/QCR9, UQCR11/QCR10 and a cleavage product of Rieske/UQCRFS1). UQCRC2 is part of the hydrophobic core of the b-c1 complex and is necessary for the stabilization of Ubiquinol Cytochrome c Reductase.
Function:
The protein encoded by this gene is located in the mitochondrion, where it is part of the ubiquinol-cytochrome c reductase complex (also known as complex III). This complex constitutes a part of the mitochondrial respiratory chain. The core protein UQCRC2 is required for the assembly and stabilization of the complex.
Clinical Significance:
Variants of UQCRC2 have been associated with mitochondrial complex III deficiency, nuclear, type 5. Mitochondrial complex III deficiency nuclear type 5 is a disorder of the mitochondrial respiratory chain resulting in a highly variable phenotype depending on which tissues are affected. Clinical features include mitochondrial encephalopathy, psychomotor retardation, ataxia, severe failure to thrive, liver dysfunction, renal tubulopathy, muscle weakness, exercise intolerance, lactic acidosis and hypoglycemia. Homozygous mutations resulting in a change from Arginine to Tryptophan at position 183 have been associated with mitochondrial complex III deficiency due to UQCRC2 dysfunction. Autosomal recessive inheritance has been proposed as a transmission pattern.
Interactions:
UQCRC2 has 98 protein-protein interactions with 90 of them being co-complex interactions. CAC1A, QCR1, UQCRC1, CACNA1A, STOM, a8k1f4, HLA-B, ARF6, and Mapk3 have been found to interact with UQCRC2. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Transversal (combinatorics)**
Transversal (combinatorics):
In mathematics, particularly in combinatorics, given a family of sets, here called a collection C, a transversal (also called a cross-section) is a set containing exactly one element from each member of the collection. When the sets of the collection are mutually disjoint, each element of the transversal corresponds to exactly one member of C (the set it is a member of). If the original sets are not disjoint, there are two possibilities for the definition of a transversal: One variation is that there is a bijection f from the transversal to C such that x is an element of f(x) for each x in the transversal. In this case, the transversal is also called a system of distinct representatives (SDR).: 29 The other, less commonly used, does not require a one-to-one relation between the elements of the transversal and the sets of C. In this situation, the members of the system of representatives are not necessarily distinct.: 692 : 322 In computer science, computing transversals is useful in several application domains, with the input family of sets often being described as a hypergraph.
Existence and number:
A fundamental question in the study of SDR is whether or not an SDR exists. Hall's marriage theorem gives necessary and sufficient conditions for a finite collection of sets, some possibly overlapping, to have a transversal. The condition is that, for every integer k, every collection of k sets must contain in common at least k different elements.: 29 The following refinement by H. J. Ryser gives lower bounds on the number of such SDRs.: 48 Theorem. Let S1, S2, ..., Sm be a collection of sets such that Si1∪Si2∪⋯∪Sik contains at least k elements for k = 1,2,...,m and for all k-combinations { i1,i2,…,ik } of the integers 1,2,...,m and suppose that each of these sets contains at least t elements. If t ≤ m then the collection has at least t ! SDRs, and if t > m then the collection has at least t ! / (t - m)! SDRs.
Relation to matching and covering:
One can construct a bipartite graph in which the vertices on one side are the sets, the vertices on the other side are the elements, and the edges connect a set to the elements it contains. Then, a transversal (defined as a system of distinct representatives) is equivalent to a perfect matching in this graph.
One can construct a hypergraph in which the vertices are the elements, and the hyperedges are the sets. Then, a transversal (defined as a system of not-necessarily-distinct representatives) is a vertex cover in a hypergraph.
Examples:
In group theory, given a subgroup H of a group G, a right (respectively left) transversal is a set containing exactly one element from each right (respectively left) coset of H. In this case, the "sets" (cosets) are mutually disjoint, i.e. the cosets form a partition of the group.
As a particular case of the previous example, given a direct product of groups G=H×K , then H is a transversal for the cosets of K.
In general, since any equivalence relation on an arbitrary set gives rise to a partition, picking any representative from each equivalence class results in a transversal.
Examples:
Another instance of a partition-based transversal occurs when one considers the equivalence relation known as the (set-theoretic) kernel of a function, defined for a function f with domain X as the partition of the domain ker := {{y∈X∣f(x)=f(y)}∣x∈X} . which partitions the domain of f into equivalence classes such that all elements in a class map via f to the same value. If f is injective, there is only one transversal of ker f . For a not-necessarily-injective f, fixing a transversal T of ker f induces a one-to-one correspondence between T and the image of f, henceforth denoted by Im f . Consequently, a function Im f)→T is well defined by the property that for all z in Im f,g(z)=x where x is the unique element in T such that f(x)=z ; furthermore, g can be extended (not necessarily in a unique manner) so that it is defined on the whole codomain of f by picking arbitrary values for g(z) when z is outside the image of f. It is a simple calculation to verify that g thus defined has the property that f∘g∘f=f , which is the proof (when the domain and codomain of f are the same set) that the full transformation semigroup is a regular semigroup. g acts as a (not necessarily unique) quasi-inverse for f; within semigroup theory this is simply called an inverse. Note however that for an arbitrary g with the aforementioned property the "dual" equation g∘f∘g=g may not hold. However if we denote by h=g∘f∘g , then f is a quasi-inverse of h, i.e. h∘f∘h=h
Common Transversals:
A common transversal of the collections A and B (where |A|=|B|=n ) is a set that is a transversal of both A and B. The collections A and B have a common transversal if and only if, for all I,J⊂{1,...,n} ,|(⋃i∈IAi)∩(⋃j∈JBj)|≥|I|+|J|−n
Generalizations:
A partial transversal is a set containing at most one element from each member of the collection, or (in the stricter form of the concept) a set with an injection from the set to C. The transversals of a finite collection C of finite sets form the basis sets of a matroid, the transversal matroid of C. The independent sets of the transversal matroid are the partial transversals of C.An independent transversal (also called a rainbow-independent set or independent system of representatives) is a transversal which is also an independent set of a given graph. To explain the difference in figurative terms, consider a faculty with m departments, where the faculty dean wants to construct a committee of m members, one member per department. Such a committee is a transversal. But now, suppose that some faculty members dislike each other and do not agree to sit in the committee together. In this case, the committee must be an independent transversal, where the underlying graph describes the "dislike" relations.Another generalization of the concept of a transversal would be a set that just has a non-empty intersection with each member of C. An example of the latter would be a Bernstein set, which is defined as a set that has a non-empty intersection with each set of C, but contains no set of C, where C is the collection of all perfect sets of a topological Polish space. As another example, let C consist of all the lines of a projective plane, then a blocking set in this plane is a set of points which intersects each line but contains no line.
Category theory:
In the language of category theory, a transversal of a collection of mutually disjoint sets is a section of the quotient map induced by the collection.
Computational complexity:
The computational complexity of computing all transversals of an input family of sets has been studied, in particular in the framework of enumeration algorithms. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Statistical assumption**
Statistical assumption:
Statistics, like all mathematical disciplines, does not infer valid conclusions from nothing. Inferring interesting conclusions about real statistical populations almost always requires some background assumptions. Those assumptions must be made carefully, because incorrect assumptions can generate wildly inaccurate conclusions.
Here are some examples of statistical assumptions: Independence of observations from each other (this assumption is an especially common error).
Independence of observational error from potential confounding effects.
Exact or approximate normality of observations (or errors).
Linearity of graded responses to quantitative stimuli, e.g., in linear regression.
Classes of assumptions:
There are two approaches to statistical inference: model-based inference and design-based inference. Both approaches rely on some statistical model to represent the data-generating process. In the model-based approach, the model is taken to be initially unknown, and one of the goals is to select an appropriate model for inference. In the design-based approach, the model is taken to be known, and one of the goals is to ensure that the sample data are selected randomly enough for inference.
Classes of assumptions:
Statistical assumptions can be put into two classes, depending upon which approach to inference is used.
Model-based assumptions. These include the following three types: Distributional assumptions. Where a statistical model involves terms relating to random errors, assumptions may be made about the probability distribution of these errors. In some cases, the distributional assumption relates to the observations themselves.
Structural assumptions. Statistical relationships between variables are often modelled by equating one variable to a function of another (or several others), plus a random error. Models often involve making a structural assumption about the form of the functional relationship, e.g. as in linear regression. This can be generalised to models involving relationships between underlying unobserved latent variables.
Cross-variation assumptions. These assumptions involve the joint probability distributions of either the observations themselves or the random errors in a model. Simple models may include the assumption that observations or errors are statistically independent.
Design-based assumptions. These relate to the way observations have been gathered, and often involve an assumption of randomization during sampling.The model-based approach is the most commonly used in statistical inference; the design-based approach is used mainly with survey sampling. With the model-based approach, all the assumptions are effectively encoded in the model.
Checking assumptions:
Given that the validity of any conclusion drawn from a statistical inference depends on the validity of the assumptions made, it is clearly important that those assumptions should be reviewed at some stage. Some instances—for example where data are lacking—may require that researchers judge whether an assumption is reasonable. Researchers can expand this somewhat to consider what effect a departure from the assumptions might produce. Where more extensive data are available, various types of procedures for statistical model validation are available—e.g. for regression model validation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Addressable heap**
Addressable heap:
In computer science, an addressable heap is an abstract data type. Specifically, it is a mergeable heap supporting access to the elements of the heap via handles (also called references). It allows the key of the element referenced by a particular handle to be removed or decreased.
Definition:
An addressable heap supports the following operations: Make-Heap(), creating an empty heap.
Insert(H,x), inserting an element x into the heap H, and returning a handle to it.
Min(H), returning a handle to the minimum element, or Nil if no such element exists.
Extract-Min(H), extracting and returning a handle to the minimum element, or Nil if no such element exists.
Remove(h), removing the element referenced by h (from its respective heap).
Decrease-Key(h,k), decreasing the key of the element referenced by h to k; illegal if k is larger than the key referenced by h.
Merge(H1,H2), combining the elements of H1 and H2.
Examples:
Examples of addressable heaps include: Fibonacci heaps Binomial heapsA more complete list with performance comparisons can be found here. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Zeugma and syllepsis**
Zeugma and syllepsis:
In rhetoric, zeugma ( (listen); from the Ancient Greek ζεῦγμα, zeûgma, lit. "a yoking together") and syllepsis (; from the Ancient Greek σύλληψις, sullēpsis, lit. "a taking together") are figures of speech in which a single phrase or word joins different parts of a sentence.
Definition:
In current usage, there are multiple and sometimes conflicting definitions for zeugma and syllepsis. This article categorizes these two figures of speech into four types, based on four definitions: Type 1 Grammatical syllepsis (sometimes also called zeugma): where a single word is used in relation to two other parts of a sentence although the word grammatically or logically applies to only one.By definition, grammatical syllepsis will often be grammatically "incorrect" according to traditional grammatical rules. However, such solecisms are sometimes not errors but intentional constructions in which the rules of grammar are bent by necessity or for stylistic effect.
Definition:
"He works his work, I mine"This quote from Alfred Tennyson's poem "Ulysses" is ungrammatical from a grammarian's viewpoint, because "works" does not grammatically agree with "I": the sentence "I works mine" would be ungrammatical. On the other hand, Tennyson's two sentences could be taken to deploy a different figure of speech, namely "ellipsis". The sentence would be taken to mean, "He works his work, [and] I [work] mine."Read in this way, the conjunction is not ungrammatical.
Definition:
Type 2 Zeugma (often also called syllepsis, or semantic syllepsis): a single word is used with two other parts of a sentence but must be understood differently in relation to each. Example: "He took his hat and his leave." The type of figure is grammatically correct but creates its effect by seeming, at first hearing, to be incorrect by its exploiting multiple shades of meaning in a single word or phrase.
Definition:
"Here Thou, great Anna! whom three Realms obey,Dost sometimes Counsel take – and sometimes Tea." (Alexander Pope, The Rape of the Lock, Canto III) "Miss Bolo [...] went straight home, in a flood of tears and a sedan-chair." (Charles Dickens, The Pickwick Papers, Chapter 35) “They sought it with thimbles, they sought it with care; / They pursued it with forks and hope.”(Lewis Carroll, “The Hunting of the Snark”) "When she arrived later in the day, she took the point at once, but she also took the spoons." (J.R.R. Tolkien, "The Fellowship of the Ring") "She lowered her standards by raising her glass / Her courage, her eyes and his hopes..."When he asked 'What in heaven?' she made no reply, up her mind, and a dash for the door." (Flanders and Swann, "Have Some Madeira M'Dear") "They covered themselves with dust and glory." (Mark Twain, The Adventures of Tom Sawyer).
Definition:
"He watches afternoon repeats and the food he eats." (Blur, "Country House") "You held your breath and the door for me." (Alanis Morissette, "Head Over Feet") "I took the podium and my second trophy of the evening." (Samuel R. Delany, "Racism and Science Fiction") “My blood sugar fell dramatically and so did I.”(Elaine Stritch, “Elaine Stritch at Liberty”) "Quand les Français à tête folle / S'en allèrent dans l'Italie, / Ils gagnèrent à l'étourdie / Et Gênes et Naples et la Vérole." ["On their flippant way through Italy, the French carelessly picked up Genoa, Naples and syphilis."] (Voltaire)When the meaning of a verb varies for the nouns following it, there is a standard order for the nouns: the noun first takes the most prototypical or literal meaning of the verb and is followed by the noun or nouns taking the less prototypical or more figurative verb meanings.
Definition:
"The boy swallowed milk and kisses," as contrasted with "The boy swallowed kisses and milk".The opposite process, in which the first noun expresses a figurative meaning and the second a more literal meaning, tends to create a comic effect: "and she feeds me love and tenderness and macaroons." (The Stampeders, "Sweet City Woman") Type 3 The Oxford Dictionary of Literary Terms offers a much broader definition for zeugma by defining it as any case of parallelism and ellipsis working together so that a single word governs two or more other parts of a sentence.
Definition:
Vicit pudorem libido timorem audacia rationem amentia. (Cicero, Pro Cluentio, VI.15) "Lust conquered shame; audacity, fear; madness, reason."The more usual way of phrasing this would be "Lust conquered shame, audacity conquered fear, and madness conquered reason." The sentence consists of three parallel clauses, called parallel because each has the same word order: verb, object, subject in the original Latin; subject, verb, object in the English translation. The verb "conquered" is a common element in each clause. The zeugma is created in both the original and the translation by removing the second and third instances of "conquered". Removing words that still can be understood by the context of the remaining words is ellipsis.
Definition:
Histories make men wise; poets, witty; the mathematics, subtle; natural philosophy, deep; moral, grave; logic and rhetoric, able to contend. (Francis Bacon).The more usual way of phrasing this would be "Histories make men wise, poets make them witty, mathematics make them subtle, natural philosophy makes them deep, moral [philosophy] makes them grave, and logic and rhetoric make them able to contend." (Because ellipsis involves the omission of words, ambiguities can arise. The sentence could also be read as, "Histories make men wise, make poets witty, make mathematics subtle, make natural philosophy deep, makes moral [philosophy] grave, and make logic and rhetoric able to contend.") Zeugmas are defined in this sense in Samuel Johnson's 18th-century A Dictionary of the English Language.
Definition:
Type 4 A special case of semantic syllepsis occurs when a word or phrase is used both in its figurative and literal sense at the same time. Then, it is not necessary for the governing phrase to relate to two other parts of the sentence. One example is in an advertisement for a transport company: "We go a long way for you." This type of syllepsis operates in a similar manner to a homonymic pun.
Other types and related figures:
There are several other definitions of zeugma that encompass other ways in which one word in a sentence can relate to two or more others. Even a simple construction like "this is easy and comprehensible" has been called a "zeugma without complication" because "is" governs both "easy" and "comprehensible".Specialized figures have been defined to distinguish zeugmas with particular characteristics such as the following figures, which relate to the specific type and location of the governing word: Diazeugma A diazeugma is a zeugma whose only subject governs multiple verbs. A diazeugma whose only subject begins the sentence and controls a series of verbs is a "disjunction" (disiunctio) in the Rhetorica ad Herennium.
Other types and related figures:
Populus Romanus Numantiam delevit Kartaginem sustulit Corinthum disiecit Fregellas evertit. (Anon. Rhetorica ad Herennium. IV. xxvii.) The Roman people destroyed Numantia, razed Carthage, demolished Corinth, and overthrew Fregellae.
Other types and related figures:
"We shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe to assure the survival and the success of liberty." (Inaugural address of John F. Kennedy) Hypozeugma Hypozeugma or "adjunctions" (adiunctio) is used in a construction containing several phrases and occurs when the word or words on which all of the phrases depend are placed at the end.
Other types and related figures:
Assure yourself that Damon to his Pythias, Pylades to his Orestes, Titus to his Gysippus, Theseus to his Pyrothus, Scipio to his Laelius, was never found more faithful than Euphues will be to his Philautus. (John Lyly, Euphues) Prozeugma A prozeugma,synezeugmenon, or praeiunctio is a zeugma whose governing word occurs in the first clause of the sentence.
Vicit pudorem libido timorem audacia rationem amentia. (Cicero, Pro Cluentio, VI.15) "Lust conquered shame; audacity, fear; madness, reason." Histories make men wise; poets, witty; the mathematics, subtle; natural philosophy, deep; moral, grave; logic and rhetoric, able to contend. (Francis Bacon).
Mesozeugma A mesozeugma is a zeugma whose governing word occurs in the middle of the sentence and governs clauses on either side. A mesozeugma whose common term is a verb is called "conjunction" (coniunctio) in the Roman Rhetorica ad Herennium.
"What a shame is this, that neither hope of reward, nor feare of reproch could any thing move him, neither the persuasion of his friends, nor the love of his country. [sic]" (Henry Peacham) | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Abney effect**
Abney effect:
The Abney effect or the purity-on-hue effect describes the perceived hue shift that occurs when white light is added to a monochromatic light source.The addition of white light will cause a desaturation of the monochromatic source, as perceived by the human observer. However, a less intuitive effect of the perceived white light addition is the change in the apparent hue. This hue shift is physiological rather than physical in nature.
Abney effect:
This variance of hue as a result of the addition of white light was first described by the English chemist and physicist Sir William de Wiveleslie Abney in 1909, although the date is commonly reported as 1910. A white light source can be created by the combination of red, blue, and green light. Abney demonstrated that the cause of the apparent change in hue was the red and green light that comprised this light source, and that the blue light component had no contribution to the Abney effect.
Chromaticity diagrams:
Chromaticity diagrams are two-dimensional diagrams that plot the projection of the International Commission on Illumination (CIE) XYZ color space onto the (x, y) plane. The X, Y, Z values (or tristimulus values) are simply used as weightings to create new colors from the primary colors, much in the same way that RGB is used for creating colors from primaries in televisions or photographs. The x and y values used to create the chromaticity diagram are created from the XYZ values by dividing X and Y by the sum of X, Y, Z. The chromaticity values that can then be plotted are dependent upon two values: dominant wavelength and saturation. Since luminous energy is not included, colors that differ only in its lightness are not distinguished on the diagram. For instance, brown, which is just a low-luminance mixture of orange and red, will not appear as such.The Abney effect can be illustrated on chromaticity diagrams as well. If one adds white light to a monochromatic light, one will obtain a straight line on the chromaticity diagram. We might imagine that the colors along such a line are all perceived as having the same hue. In reality, this does not hold true, and a hue shift is perceived. Correspondingly, if we plot colors that are perceived as having the same hue (and only differing in purity) we will obtain a curved line.In chromaticity diagrams, a line that has constant perceived hue must be curved, so that the Abney effect is accounted for. The chromaticity diagrams that have been corrected for the Abney effect are therefore excellent illustrations of the non-linear nature of the visual system. Also, the Abney effect does not disallow any and all straight lines on chromaticity diagrams. One may mix two monochromatic lights and not see a shift in hue, thereby suggesting a straight-line plot for the different levels of mixture would be appropriate on a chromaticity diagram.
Physiology:
The opponent process model of the visual system is composed of two chromatic neural channels and one achromatic neural channel. The chromatic channels consist of a red-green channel and a yellow-blue channel and transmit color information. The achromatic channel is responsible for luminance, or white-black discrimination. Hue and saturation are perceived due to varying amounts of activity in these neural channels consisting of axon pathways from retinal ganglion cells. These three channels are tied closely to reaction time in response to colors. The achromatic neural channel has a faster response time than the chromatic neural channels under most conditions. The functions of these channels are task-dependent. Some activities are dependent on one channel or the other, as well as both channels. When a colored stimulus is summed with a white stimulus, both the chromatic and achromatic channels are activated. The achromatic channel will have a slightly slowed response time, since it must adjust to the different luminance; however, despite this delayed response, the speed of the achromatic channel will still be faster than that of the chromatic channel. In these conditions of summed stimuli, the magnitude of the signal emitted by the achromatic channel will be stronger than of the chromatic channel. The coupling of a faster response with a higher amplitude from the achromatic channel means that reaction time will most likely depend on the luminance and saturation levels of the stimuli.The customary explanations for color vision explain the difference in hue perception as elemental sensations that are inherent to the physiology of the observer. However, no specific physiological constraints or theories have been able to explain the response to each unique hue. To this end, both the observer’s spectral sensitivity and relative number of cone types have proven to not play any significant role in perceiving different hues. Perhaps the environment plays a larger role in the perception of unique hues than the different physiological features across individuals. This is supported by the fact that color judgments can vary depending on differences in the color environment across long periods of time, but these same chromatic and achromatic judgments are held constant if the color environment is the same, despite aging and other individual physiological factors affecting the retina.Like the Bezold–Brücke effect, the Abney effect suggests a non-linearity between the cone responses (LMS) to the stage of hue perception.
Colorimetric purity:
The saturation, or degree of paleness of a color, is related to colorimetric purity. The equation for colorimetric purity is: P = L/(Lw + L). In this equation, L equals the luminance of the colored light stimulus, Lw is the luminance of the white light stimulus to be mixed with the colored light. The above equation is a way of quantifying the amount of white light that is mixed with the colored light. In the case of pure spectral color, with no white light added, L equals one and Lw equals zero. This means colorimetric purity would equal one, and for any case involving the addition of white light, the colorimetric purity, or the value of P, would be less than one. The purity of a spectral color stimulus can be altered by adding white, black, or gray stimulus. However, the Abney effect describes the change in colorimetric purity by the addition of white light. In order to determine the effect that changing the purity has on the perceived hue, it is important that purity be the only variable in the experiment; luminance must be kept constant.
Hue discrimination:
The term hue discrimination is used to describe the change in wavelength that must be obtained in order for the eye to detect a shift in hue. An expression λ + Δλ defines the required wavelength adjustment that must take place. A small (< 2 nm) change in wavelength causes most spectral colors to appear to take on a different hue. However, for blue light and red light, a much larger wavelength shift must occur in order for a person to be able to identify a difference in hue.
History:
The original article describing the Abney effect was published by Sir William de Wiveleslie Abney in Proceedings of the Royal Society of London, Series A in December 1909. He decided to do quantitative research following the discovery that the visual observations of color did not match the dominant colors obtained photographically when using models of fluorescence.
History:
A color-measuring apparatus commonly used in experiments in the 1900s was used in conjunction with partially silvered mirrors to split one beam of light into two beams. This resulted in two beams of light parallel to one another having the same intensity and color. The beams of light were projected onto a white background, creating patches of light that were 1.25-inch (32 mm) squares. The white light was added to one of the patches of colored light, the patch on the right. A rod was inserted in the path of the two beams so that there would be no space in between the colored surfaces. An additional rod was used to create a shadow where the white light scattered onto the patch that was not to receive addition of white light (the patch on the left side). The amount of white light added was determined as one half of the luminosity of the colored light. The red light source, for example, had more white light added than the yellow light source. He began using two patches of red light, and in fact, the addition of white light to the light patch on the right caused a more yellow tone than the pure red light source. The same results happened when the experimental light source was orange. When the light source was green, the addition of white light caused the appearance of the patch to become yellow-green. Subsequently, when white light was added to yellow-green light, the patch of light appeared primarily yellow. In a mixture of blue-green light (with a slightly higher percentage of blue) with white light, the blue appeared to take on a reddish hue. In the case of a violet light source, the addition of white light caused the violet light to take on a blue tint.Abney hypothesized that the resulting change in hue that occurred was due to the red light and green light that were components of the white light being added. He also thought that the blue light that also comprises the white light beam was a negligible factor that had no effect on the apparent hue shift. Abney was able to prove his hypothesis experimentally by matching his experimental values of percentage composition and luminosities of red, green, and blue sensations to the calculated values almost exactly. He examined the percentage composition and luminosity found in the different spectral colors as well as the white light source that was added.
Similar effect of bandwidth:
While the nonlinearity of neural color-coding, as evidenced by the classical understanding of the Abney effect and its use of white light to particular wavelengths of light, has been thoroughly studied in the past, a new method was undertaken by researchers at the University of Nevada. Rather than adding white light to monochromatic light, the bandwidth of the spectrum was varied. This variation of bandwidth directly targeted the three classes of cone receptors as a means of identifying any hue shifts as perceived by the human eye. The overall goal of the research was to determine whether the appearance of color was affected by the filtering effects of the spectral sensitivity of the eye. Experiments showed that the cone ratios signaled a hue was adjusted so as to produce a constant hue that matched the central wavelength of the light source. Also, the experiments conducted essentially showed that the Abney effect does not hold for all changes in light purity, but is limited very much to certain means of purity degradation, namely the addition of white light. Since the experiments undertaken varied the bandwidth of the light, a similar albeit different means of altering the purity and therefore hue of the monochromatic light, the nonlinearity of the results displayed differently from what had traditionally been seen. Ultimately, the researchers came to the conclusion that variations in spectral bandwidth cause postreceptoral mechanisms to compensate for the filtering effects imposed by cone sensitivities and preretinal absorption and that the Abney effect occurs because the eye has, in a sense, been tricked into seeing a color that would not naturally occur and must therefore approximate the color. This approximation to compensate for the Abney effect is a direct function of the cone excitations experienced with a broadband spectrum.
Miscellaneous facts:
A patent for a color printer that claims to compensate for the Abney effect was published in 1995.The Abney effect must be taken into account when designing the cockpit for modern fighter planes. The colors viewed on the screen become desaturated when white light strikes the screen, so special considerations are made to counteract the Abney effect.A wide array of spectral colors exist that can be made to exactly match a pure color by adding various levels of white light.It remains unknown whether the Abney effect is a resulting phenomenon that occurs by chance during color perception or the effect plays a deliberate function in the way the eye codes for color.
Modeling:
The Abney effect is rarely described by known color appearance models. Of the many models Fairchild reviewed in Color Appearance Models (3 ed.), only the Hunt and ATD models predict the Abney effect. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Precordium**
Precordium:
In anatomy, the precordium or praecordium is the portion of the body over the heart and lower chest.Defined anatomically, it is the area of the anterior chest wall over the heart. It is therefore usually on the left side, except in conditions like dextrocardia, where the individual's heart is on the right side. In such a case, the precordium is on the right side as well.
Precordium:
The precordium is naturally a cardiac area of dullness. During examination of the chest, the percussion note will therefore be dull. In fact, this area only gives a resonant percussion note in hyperinflation, emphysema or tension pneumothorax.
Precordial chest pain can be an indication of a variety of illnesses, including costochondritis and viral pericarditis. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Amantadine**
Amantadine:
Amantadine, sold under the brand name Gocovri among others, is a medication used to treat dyskinesia associated with parkinsonism and influenza caused by type A influenzavirus, though its use for the latter is no longer recommended due to widespread drug resistance. It acts as a nicotinic antagonist, dopamine agonist, and noncompetitive NMDA antagonist. The antiviral mechanism of action is antagonism of the influenzavirus A M2 proton channel, which prevents endosomal escape (i.e. the release of viral genetic material into the host cytoplasm).Amantadine was first used for the treatment of influenza A. After antiviral properties were initially reported in 1963, amantadine received approval for prophylaxis against the influenza virus A in 1976. In 1973, the Food and Drug Administration (FDA) approved amantadine for use in the treatment of Parkinson's disease. In 2017, the extended release formulation was approved for use in the treatment of levodopa-induced dyskinesia.
Amantadine:
Amantadine has a mild side effect profile. Common neurological side effects include drowsiness, light headedness, dizziness, and confusion. Due to its effects on the central nervous system, it is only with caution that it should be combined with additional CNS stimulants or anticholinergic drugs. Amantadine is contraindicated in persons with end stage kidney disease, given that the drug is cleared by the kidneys. It should also be taken with caution in those with enlarged prostates or glaucoma, due to its anticholinergic effects.
Chemical structure:
Amantadine (brand names Gocovri, Symadine, and Symmetrel) is the organic compound 1-adamantylamine or 1-aminoadamantane, which consists of an adamantane backbone with an amino group substituted at one of the four methyne positions. Rimantadine is a closely related adamantane derivative with similar biological properties; both target the M2 proton channel of influenza A virus.
Mechanism of action:
Parkinson's disease The mechanism of its antiparkinsonian effect is poorly understood. Amantadine is a weak antagonist of the NMDA-type glutamate receptor, increases dopamine release, and blocks dopamine reuptake. Amantadine probably does not inhibit monoamine oxidase (MAO) enzyme. Moreover, the drug has many effects in the brain, including release of dopamine and norepinephrine from nerve endings. It appears to be an anticholinergic (specifically at alpha-7 nicotinic receptors) like the similar pharmaceutical memantine.In 2004, it was discovered that amantadine and memantine bind to and act as agonists of the σ1 receptor (Ki = 7.44 μM and 2.60 μM, respectively), and that activation of the σ1 receptor is involved in the dopaminergic effects of amantadine at therapeutically relevant concentrations. There has been speculation that these findings may also extend to the other adamantanes such as adapromine, rimantadine, and bromantane, and could explain the psychostimulant-like effects of this family of compounds, but there does not seem to be any evidence available now regarding this theory.
Mechanism of action:
Influenza The mechanisms for amantadine's antiviral and antiparkinsonian effects are unrelated. Amantadine targets the influenza A M2 ion channel protein. The M2 protein's function is to allow the intracellular virus to replicate (M2 also functions as a proton channel for hydrogen ions to cross into the vesicle), and exocytose newly formed viral proteins to the extracellular space (viral shedding). By blocking the M2 channel, the virus is unable to replicate because of impaired replication, protein synthesis, and exocytosis.Amantadine and rimantadine function in a mechanistically identical fashion, entering the barrel of the tetrameric M2 channel and blocking pore function—i.e., proton translocation.Resistance to the drug class is a consequence of mutations to the pore-lining amino acid residues of the channel, preventing both amantadine and rimantadine from binding and inhibiting the channel in their usual way.
Pharmacokinetics:
Amantadine is well absorbed orally. The onset of action is usually within 48 hours when used for parkinsonian syndromes, including dyskinesia. As plasma concentrations of amantadine increase, there is a greater risk for toxicity.Half-life elimination averages eight days in patients with end-stage kidney disease. Amantadine is only minimally removed by hemodialysis.Amantadine is metabolized to a small extent (5-15%) by acetylation. It is mainly excreted (90%) unchanged in urine by kidney excretion.
Medical uses:
Parkinson's disease Amantadine is used to treat Parkinson's disease-related dyskinesia and drug-induced parkinsonism syndromes. Amantadine may be used alone or in combination with another anti-Parkinson's or anticholinergic drug. The specific symptoms targeted by amantadine therapy are dyskinesia and rigidity. The extended release amantadine formulation is commonly used to treat dyskinesias in people receiving levodopa therapy for Parkinson's disease. A 2003 Cochrane review had concluded there was insufficient evidence to prove the safety or efficacy of amantadine to treat dyskinesia.In 2008, the World Health Organization reported amantadine is not effective as a stand-alone parkinsonian therapy, but recommended it could be used in combination therapy with levodopa.
Medical uses:
Influenza A Amantadine is not recommended for treatment or prophylaxis of influenza A in the United States. Amantadine has no effect preventing or treating influenza B infections. The US Centers for Disease Control and Prevention found 100% of seasonal H3N2 and 2009 pandemic flu samples were resistant to adamantanes (amantadine and rimantadine) during the 2008–2009 flu season.The U.S. Centers for Disease Control and Prevention (CDC) guidelines recommend only neuraminidase inhibitors for influenza treatment and prophylaxis. The CDC recommends against amantadine and rimantadine to treat influenza A infections.Similarly, the 2011 World Health Organization (WHO) virology report showed all tested H1N1 influenza A viruses were resistant to amantadine. WHO guidelines recommend against use of M2 inhibitors for influenza A. The continued high rate of resistance observed in laboratory testing of influenza A has reduced the priority of M2 resistance testing.A 2014 Cochrane review did not find evidence for efficacy or safety of amantadine used for the prevention or treatment of influenza A.
Medical uses:
Extra-pyramidal side effects An extended release formulation is used to treat levodopa-induced dyskinesia in patients with Parkinson's disease. The WHO recommends the use of amantadine as a combination therapy to reduce levodopa side effects.
Medical uses:
Off-label uses Fatigue in multiple sclerosis A 2007 Cochrane literature review concluded that there was no overall evidence supporting the use of amantadine in treating fatigue in patients with MS. A follow-up 2012 Cochrane review stated that there may be some amantadine-induced improvement in fatigue in some people with MS. Despite multiple control trials that have also demonstrated improvements in subjective and objective ratings of fatigue, there is no final conclusion regarding its effectiveness.Consensus guidelines from the German Multiple Sclerosis Society (GMSS) in 2006 state that amantadine produces moderate improvement in subjective fatigue, problem solving, memory, and concentration. Thus, in 2006, GMSS guidelines recommended the use of amantadine in MS-related fatigue.In the UK NICE recommends considering amantadine for MS fatigue.
Medical uses:
Awareness in patients with disorders of consciousness Disorders of consciousness (DoC) include coma, vegetative state (VS), and minimally conscious state (MCS). Amantadine has been shown to increase the rate of emergence from a MCS, defined by consistent demonstration of interactive communication and functional objective use. In traumatic brain injury patients in the intensive care unit, amantadine has also been shown in various randomized control trials to increase the rate of functional recovery and arousal, particularly in the time period immediately following an injury. There are also reports of significantly improved consciousness in patients treated for non-traumatic cases of DoC, such as in the case of a subarachnoid hemorrhage, cerebral hemorrhage, and hypoxic encephalopathy. In 2018 the American Academy of Neurology (AAN) updated treatment guidelines on the use of amantadine for patients with prolonged DoC, recommending the use of amantadine (100–200 mg bid) for adults with DoC 4–16 weeks post injury to support early functional recovery and reduce disability.
Medical uses:
Neuroplasticity and overall functional recovery in patients with brain injury In various studies, amantadine and memantine have been shown to accelerate the rate of recovery from a brain injury. The time-limited window following a brain injury is characterized by neuroplasticity, or the capacity of neurons in the brain to adapt and compensate after injury. Thus, physiatrists will often start patients on amantadine as soon as impairments are recognized. There are also case reports showing improved functional recovery with amantadine treatment occurring years after the initial brain injury. There is insufficient evidence to determine if the functional gains are a result of effects through the dopamine or norepinephrine pathways. Some patients may benefit from direct dopamine stimulation with amantadine, while others may benefit more from other stimulants that act more on the norepinephrine pathway, such as methylphenidate. It is unclear if treatment with amantadine improves long-term outcomes or simply accelerates recovery. Nonetheless, amantadine-induced acceleration of recovery reduces the burden of disability, lessens health care costs, and minimizes psychosocial stressors in patients.
Medical uses:
Attention deficit hyperactivity disorder A 2010 randomized clinical trial showed similar improvements in ADHD symptoms in children treated with amantadine as in those treated with methylphenidate, with less frequent side effects. A 2021 retrospective study showed that amantadine may serve as an effective adjunct to stimulants for ADHD–related symptoms and appears to be a safer alternative to second- or third-generation antipsychotics.
Adverse effects:
Amantadine is generally well tolerated and has a mild side-effect profile.
Adverse effects:
Neurological Side effects include drowsiness (especially while driving), lightheadedness, falls, and dizziness. Patients on amantadine should avoid combination with other central nervous system (CNS) depressing agents, such as alcohol. Excessive alcohol usage may increase the potential for CNS effects such as dizziness, confusion, and light headedness.Rare severe adverse effects include neuroleptic malignant syndrome, depression, convulsions, psychosis, and suicidal ideation. It has also been associated with disinhibited actions (gambling, sexual activity, spending, other addictions) and diminished control over compulsions.
Adverse effects:
Cardiovascular Amantadine may cause orthostatic hypotension, syncope, and peripheral edema.
Gastrointestinal Amantadine has also been associated with dry mouth and constipation.
Skin Rare cases of skin rashes, such as Stevens–Johnson syndrome and livedo reticularis have also been reported in patients treated with amantadine.
Adverse effects:
Kidney Amantadine inhibits the kidney's active-transport removal and transfer of creatinine from blood to urine, which normally occurs in the proximal tubules of the nephrons. The active-transport removal mechanism accounts for about fifteen percent of creatinine clearance. Therefore, amantadine may increase serum creatinine concentrations fifteen percent above normal levels and give the false impression of mild kidney disease in patients whose kidneys are actually undamaged (because kidney function is often assessed by measuring the concentration of creatinine in blood.) Also, if the patient does have kidney disease, amantadine may cause it to appear as much as fifteen percent worse than it actually is.
Adverse effects:
Pregnancy and lactation Amantadine is Food and Drug Administration category C for pregnancy. Teratogenic effects have been observed in humans (case reports) and animal reproduction studies. Amantadine may also be present in breast milk and negatively alter breast milk production or excretion. The decision to breastfeed during amantadine therapy should consider the risk of infant exposure, the benefits of breastfeeding, and the benefits of the drug to the mother.
Interactions:
Amantadine may affect the central nervous system due to dopaminergic and anticholinergic properties. The mechanisms of action are not fully known. Because of the CNS effects, caution is required when prescribing additional CNS stimulants or anticholinergic drugs. Thus, concurrent use of alcohol with Amantadine is not recommended due to enhanced CNS depressant effects. In addition, anti-dopaminergic drugs such as metoclopramide and typical anti-psychotics should be avoided. These interactions are likely related to opposing dopaminergic mechanisms of action, which inhibits amantadine's anti-Parkinson effects.
Contraindications:
Amantadine is contraindicated in persons with end stage kidney disease. The drug is renally cleared.Amantadine may have anticholinergic side effects. Thus, patients with an enlarged prostate or glaucoma should use with caution.Live attenuated vaccines are contraindicated while taking amantadine. It is possible that amantadine will inhibit viral replication and reduce the efficacy of administered vaccines. The U.S. Food and Drug Administration recommends avoiding amantadine for two weeks prior to vaccine administration and 48 hours afterward.
History:
Influenza A Antiviral properties were first reported in 1963 at the University of Illinois Hospital in Chicago. In this amantadine trial study volunteer college students were exposed to a viral challenge. The group that received amantadine (100 milligrams 18 hours before viral challenge) had less Asia influenza infections than the placebo group. Amantadine received approval for the treatment of influenza virus A in adults in 1976. It was first used in West Germany in 1966. Amantadine was approved by the U.S. Food and Drug Administration in October 1968, as a prophylactic agent against Asian (H2N2) influenza and received approval for prophylactic use for influenza A in 1976.During the 1980 influenza A epidemic, the first amantadine-resistance influenza viruses were reported. The frequency of amantadine resistance among influenza A (H3N2) viruses from 1991 and 1995 was as low as 0.8%. In 2004 the resistance frequency increased to 12.3%. A year later resistance increase significantly to 96%, 72%, and 14.5% in China, South Korea, and the United States, respectively. By 2006, 90.6% of H3N2 strains and 15.6% of H1N1 were amantadine-resistant. A majority of the amantadine-resistant H3N2 isolates (98.2%) were found to contain an S31N mutation in the M2 transmembrane domain that confers resistance to amantadine. Currently, adamantane resistance is high among circulating influenza A viruses. Thus, they are no longer recommended for treatment of influenza A.
History:
Parkinson's disease An incidental finding in 1969 prompted investigations about amantadine's effectiveness for treating symptoms of Parkinson's disease. A woman with Parkinson's disease was prescribed amantadine to treat her influenza infection and reported her cogwheel rigidity and tremors improved. She also reported that her symptoms worsened after she finished the course of amantadine. The published case report was not initially corroborated by any other instances by the medical literature or manufacturer data. A team of researchers looked at a group of ten patients with Parkinson's disease and gave them amantadine. Seven of the ten patients showed improvement, which was convincing evidence for the need of a clinical trial, which included 163 patients with Parkinson's disease and 66% experienced subjective or objective reduction of symptoms with a maximum daily dose of 200 mg. Additional studies followed patients for greater lengths of time and in different combinations of neurological drugs. It was found to be a safe drug that could be used over long periods of time with few side effects as monotherapy or in combination with L-dopa or anti-cholinergic drugs. By April 1973, the U.S. Food and Drug Administration approved amantadine for use in the treatment of Parkinson's disease.In 2017, the U.S. Food and Drug Administration approved the use of amantadine in an extended release formulation for the treatment of dyskinesia, an adverse effect of levodopa in people with Parkinson's disease.
Veterinary misuse:
In 2005, Chinese poultry farmers were reported to have used amantadine to protect birds against avian influenza. In Western countries and according to international livestock regulations, amantadine is approved only for use in humans. Chickens in China have received an estimated 2.6 billion doses of amantadine. Avian flu (H5N1) strains in China and southeast Asia are now resistant to amantadine, although strains circulating elsewhere still seem to be sensitive. If amantadine-resistant strains of the virus spread, the drugs of choice in an avian flu outbreak will probably be restricted to neuraminidase inhibitors oseltamivir and zanamivir which block the action of viral neuraminidase enzyme on the surface of influenza virus particles. However, there is an increasing incidence of oseltamivir resistance in circulating influenza strains (e.g., H1N1), highlighting the need for new anti-influenza therapies.In September 2015, the U.S. Food and Drug Administration announced the recall of Dingo Chip Twists "Chicken in the Middle" dog treats because the product has the potential to be contaminated with amantadine. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Plen**
Plen:
PLEN is a small desktop toy humanoid robot that can replicate complex human movements. It is controlled remotely by use of a Bluetooth enabled phone. When programmed, it is able to use a skateboard, rollerskates, pick up, kick and throw small things, and stand up if he tumbles to the floor. It does not feature any sensors or automatic software reactions to certain events, as it is entirely remote-controlled.
Plen:
Videos of PLEN are being widely distributed and featured on sites such as YouTube, notably for its ability to perform roller skating and skateboard stunts. It performs these feats in a very lifelike fashion.
Plen:
PLEN is 9 inches (22.8 cm) tall, weighs 696 grams and is equipped with a 3 axis accelerometer to assist in balancing. It has 18 degrees of freedom and a 32bit ARM7 CPU. PLEN is powered by 6V-950mA NiMH rechargeable battery. The battery pack is on the robot's back and resembles a backpack. Its central positioning is designed to improve overall balance as it heaviest component. New actions are programmable using its Motion Editor software and can be uploaded via USB or Bluetooth. Plen is expected to sell for 250,000 JPY.PLEN was created and manufactured by Akazawa Co. Ltd of Japan, and is currently sold by them for 262,500 ¥. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Veress needle**
Veress needle:
A Veress needle or Veres needle is a spring-loaded needle used to create pneumoperitoneum for laparoscopic surgery. Of the three general approaches to laparoscopic access, the Veress needle technique is the oldest and most traditional.
History:
The tool was first developed in 1932 by János Veres(s) (1903–1979), a Hungarian internist working with tuberculosis patients. At the time, one of the mainstays of treatment was to collapse an infected lung and allow lesions to heal. The needle was introduced as a safer technique to give patients such pneumothoraces. It was not until 1938, when he published his invention in the German literature, that the needle became more broadly known outside of Hungary.Raoul Palmer introduced the use of the Veress needle in laparoscopy to establish a pneumoperitoneum.
Description:
Modern needles are 12 to 15 cm long, with an external diameter of 2 mm. The outer cannula consists of a beveled needle point for cutting through tissues of the abdominal wall. A spring-loaded, inner stylet is positioned within the outer cannula. This inner stylet has a dull tip to protect any viscera from injury by the sharp, outer cannula. Direct pressure on the tip—as when penetrating through tissue—pushes the dull stylet into the shaft of the outer cannula. When the tip of the needle enters a space such as the peritoneal cavity, the dull, inner stylet springs forward. Carbon dioxide is then passed through the Veress needle to inflate the space, creating a pneumoperitoneum.
Use:
In a large survey of 155,987 gynecologic procedures and 17,216 general surgery procedures, the Veress needle technique was used in 78% of them. Gynecologists (81%) used the tool more often than general surgeons (48%) who are far more likely to use the open access technique.
Iatrogenics:
Several studies have pointed out that for various laparoscopic surgical applications (such as cholecystectomy, groin hernia repairs and appendectomies), creating pneumoperitoneum by using a Veress needle is not always as safe and effective as other techniques (e.g. direct trocar insertion (DTI)). However, some other prospective studies point out that there is no significant difference between the technique chosen and incidence of complications by inducing pneumoperitoneum using a Veress needle or the Hasson technique.
Iatrogenics:
Between the complications associated to this instrument it can be found: Injury to hollow viscous Bleeding Failure to achieve pneumoperitoneum Prepneumoperitoneum Biloma due to liver puncture.
Vascular injury | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Ambiguous grammar**
Ambiguous grammar:
In computer science, an ambiguous grammar is a context-free grammar for which there exists a string that can have more than one leftmost derivation or parse tree. Every non-empty context-free language admits an ambiguous grammar by introducing e.g. a duplicate rule. A language that only admits ambiguous grammars is called an inherently ambiguous language. Deterministic context-free grammars are always unambiguous, and are an important subclass of unambiguous grammars; there are non-deterministic unambiguous grammars, however.
Ambiguous grammar:
For computer programming languages, the reference grammar is often ambiguous, due to issues such as the dangling else problem. If present, these ambiguities are generally resolved by adding precedence rules or other context-sensitive parsing rules, so the overall phrase grammar is unambiguous. Some parsing algorithms (such as (Earley or GLR parsers) can generate sets of parse trees (or "parse forests") from strings that are syntactically ambiguous.
Examples:
Trivial language The simplest example is the following ambiguous grammar (with start symbol A) for the trivial language that consists of only the empty string: A → A | ε…meaning that the nonterminal A can be derived to either itself again, or to the empty string. Thus the empty string has leftmost derivations of length 1, 2, 3, and indeed of any length, depending on how many times the rule A → A is used.
Examples:
This language also has an unambiguous grammar, consisting of a single production rule: A → ε…meaning that the unique production can produce only the empty string, which is the unique string in the language.
In the same way, any grammar for a non-empty language can be made ambiguous by adding duplicates.
Examples:
Unary string The regular language of unary strings of a given character, say 'a' (the regular expression a*), has the unambiguous grammar: A → aA | ε…but also has the ambiguous grammar: A → aA | Aa | εThese correspond to producing a right-associative tree (for the unambiguous grammar) or allowing both left- and right- association. This is elaborated below.
Examples:
Addition and subtraction The context free grammar A → A + A | A − A | ais ambiguous since there are two leftmost derivations for the string a + a + a: As another example, the grammar is ambiguous since there are two parse trees for the string a + a − a: The language that it generates, however, is not inherently ambiguous; the following is a non-ambiguous grammar generating the same language: A → A + a | A − a | a Dangling else A common example of ambiguity in computer programming languages is the dangling else problem. In many languages, the else in an If–then(–else) statement is optional, which results in nested conditionals having multiple ways of being recognized in terms of the context-free grammar.
Examples:
Concretely, in many languages one may write conditionals in two valid forms: the if-then form, and the if-then-else form – in effect, making the else clause optional:In a grammar containing the rules Statement → if Condition then Statement | if Condition then Statement else Statement | ...
Condition → ...
Examples:
some ambiguous phrase structures can appear. The expression if a then if b then s else s2 can be parsed as either if a then begin if b then s end else s2 or as if a then begin if b then s else s2 end depending on whether the else is associated with the first if or second if.
Examples:
This is resolved in various ways in different languages. Sometimes the grammar is modified so that it is unambiguous, such as by requiring an endif statement or making else mandatory. In other cases the grammar is left ambiguous, but the ambiguity is resolved by making the overall phrase grammar context-sensitive, such as by associating an else with the nearest if. In this latter case the grammar is unambiguous, but the context-free grammar is ambiguous.
Examples:
An unambiguous grammar with multiple derivations The existence of multiple derivations of the same string does not suffice to indicate that the grammar is ambiguous; only multiple leftmost derivations (or, equivalently, multiple parse trees) indicate ambiguity.
Examples:
For example, the simple grammar S → A + A A → 0 | 1 is an unambiguous grammar for the language { 0+0, 0+1, 1+0, 1+1 }. While each of these four strings has only one leftmost derivation, it has two different derivations, for example S ⇒ A + A ⇒ 0 + A ⇒ 0 + 0 and S ⇒ A + A ⇒ A + 0 ⇒ 0 + 0 Only the former derivation is a leftmost one.
Recognizing ambiguous grammars:
The decision problem of whether an arbitrary grammar is ambiguous is undecidable because it can be shown that it is equivalent to the Post correspondence problem. At least, there are tools implementing some semi-decision procedure for detecting ambiguity of context-free grammars.The efficiency of parsing a context-free grammar is determined by the automaton that accepts it. Deterministic context-free grammars are accepted by deterministic pushdown automata and can be parsed in linear time, for example by an LR parser. They are a strict subset of the context-free grammars, which are accepted by pushdown automata and can be parsed in polynomial time, for example by the CYK algorithm. Unambiguous context-free grammars can be nondeterministic. For example, the language of even-length palindromes on the alphabet of 0 and 1 has the unambiguous context-free grammar S → 0S0 | 1S1 | ε. An arbitrary string of this language cannot be parsed without reading all its symbols first, which means that a pushdown automaton has to try alternative state transitions to accommodate for the different possible lengths of a semi-parsed string.Nevertheless, removing grammar ambiguity may produce a deterministic context-free grammar and thus allow for more efficient parsing. Compiler generators such as YACC include features for resolving some kinds of ambiguity, such as by using the precedence and associativity constraints.
Inherently ambiguous languages:
While some context-free languages (the set of strings that can be generated by a grammar) have both ambiguous and unambiguous grammars, there exist context-free languages for which no unambiguous context-free grammar can exist. Such languages are called inherently ambiguous.
There are no inherently ambiguous regular languages.The existence of inherently ambiguous context-free languages was proven with Parikh's theorem in 1961 by Rohit Parikh in an MIT research report.The language or where n,n′,m,m′≥1} is inherently ambiguous.Ogden's lemma can be used to prove that certain context-free languages, such as {anbmcm|m,n≥1}∪{ambmcn|m,n≥1} , are inherently ambiguous. See this page for a proof.
Inherently ambiguous languages:
The union of {anbmcmdn∣n,m>0} with {anbncmdm∣n,m>0} is inherently ambiguous. This set is context-free, since the union of two context-free languages is always context-free. But Hopcroft & Ullman (1979) give a proof that any context-free grammar for this union language cannot unambiguously parse strings of form anbncndn,(n>0) .More examples, and a general review of techniques for proving inherent ambiguity of context-free languages, are found given by Bassino and Nicaud (2011). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Interference filter**
Interference filter:
An interference filter or dichroic filter is an optical filter that reflects one or more spectral bands or lines and transmits others, while maintaining a nearly zero coefficient of absorption for all wavelengths of interest. An interference filter may be high-pass, low-pass, bandpass, or band-rejection.
Interference filter:
An interference filter consists of multiple thin layers of dielectric material having different refractive indices. There also may be metallic layers. In its broadest meaning, interference filters comprise also etalons that could be implemented as tunable interference filters. Interference filters are wavelength-selective by virtue of the interference effects that take place between the incident and reflected waves at the thin-film boundaries. The important characteristic of the filter is the form of the leaving signal. It is considered that the best form is a rectangle.
Additional sources:
This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22.
M. Bass, Handbook of Optics (2nd ed.) pp. 42.89-42.90 (1995) | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Hydrogen dehydrogenase**
Hydrogen dehydrogenase:
In enzymology, a hydrogen dehydrogenase (EC 1.12.1.2) is an enzyme that catalyzes the chemical reaction H2 + NAD+ ⇌ H+ + NADHThus, the two substrates of this enzyme are H2 and NAD+, whereas its two products are H+ and NADH.
Hydrogen dehydrogenase:
This enzyme belongs to the family of oxidoreductases, specifically those acting on hydrogen as donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is hydrogen:NAD+ oxidoreductase. Other names in common use include H2:NAD+ oxidoreductase, NAD+-linked hydrogenase, bidirectional hydrogenase, and hydrogenase. This enzyme participates in glyoxylate and dicarboxylate metabolism and methane metabolism. It has 6 cofactors: FAD, Iron, FMN, Flavin, Nickel, and Iron-sulfur. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Multi Protocol File System**
Multi Protocol File System:
The Multi Protocol File System (MPFS) is a multi-path network filesystem technology developed and sold by EMC Corporation. MPFS is intended to allow hundreds to thousands of client computer nodes to access shared computer data with higher performance than conventional NAS file-sharing protocols such as NFS.
Description:
MPFS technology is intended for HPC (High Performance Computing) environments in which multiple compute nodes require concurrent access to data sets. This technology can be used to store and access data for grid computing, where the individual computing power of many systems is combined to perform a single process. Example uses include processing geological data, voice recognition datasets, and modal processing. Virtualized computing environments will also benefit from high performance shared storage.MPFS consists of an agent on the client system and a compatible NAS storage system. The client agent splits the data and meta data for the file being requested. This is done using an FMP (File Mapping Protocol). Requests for the data and its location are sent over conventional NFS to the NAS system. Block data is sent and retrieved directly from the storage device via iSCSI or Fibre Channel. Retrieving data directly from the storage device increases performance by eliminating the file system and protocol overhead associated with NFS or SMB.The MPFS protocol was developed by EMC for use in NAS storage environments utilizing EMC Celerra and back end storage environments such as the EMC CLARiiON, EMC VNX and Symmetrix. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Capital region**
Capital region:
A capital region, also called a capital district or capital territory, is a region or district surrounding the country's capital city. It is not always the official term for the region, but may sometimes be used as an informal synonym. Capital regions can exist for either national or subnational capitals. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Douglas Wahlsten**
Douglas Wahlsten:
Douglas Leon Wahlsten (born October 13, 1943) is a Canadian neuroscientist, psychologist, and behavior geneticist. He is a professor emeritus of psychology at the University of Alberta. As of 2011, he was also a visiting professor at the University of North Carolina at Greensboro in North Carolina, United States. He is known for his laboratory research on the behavior of mice, and for his theoretical writings on a wide range of other topics. His laboratory research has included studies of the effects of different laboratory environments and experimenter characteristics on the results of mouse studies. He and his colleagues have also developed an altered form of the rotarod performance test involving wrapping sandpaper around the rod, to reduce the ability of mice to grip the rod and ride around on it. He has criticized some of his fellow behavior geneticists for trying to separate the effects of genes and the environment on human intelligence, an endeavor he considers futile. He also met and became friends with Leilani Muir, later helping to edit her autobiography, A Whisper Past. He was the president of the International Behavioural and Neural Genetics Society from 2000 to 2001.Wahlsten is a member of the editorial board of Genes, Brain and Behavior, has co-edited a book on Techniques for the Genetic Analysis of Brain and Behavior focussing on the mouse, and authored acclaimed books on mouse behavior testing and human behavioral neurogenetics. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**U2 spliceosomal RNA**
U2 spliceosomal RNA:
U2 spliceosomal snRNAs are a species of small nuclear RNA (snRNA) molecules found in the major spliceosomal (Sm) machinery of virtually all eukaryotic organisms. In vivo, U2 snRNA along with its associated polypeptides assemble to produce the U2 small nuclear ribonucleoprotein (snRNP), an essential component of the major spliceosomal complex. The major spliceosomal-splicing pathway is occasionally referred to as U2 dependent, based on a class of Sm intron—found in mRNA primary transcripts—that are recognized exclusively by the U2 snRNP during early stages of spliceosomal assembly. In addition to U2 dependent intron recognition, U2 snRNA has been theorized to serve a catalytic role in the chemistry of pre-RNA splicing as well. Similar to ribosomal RNAs (rRNAs), Sm snRNAs must mediate both RNA:RNA and RNA:protein contacts and hence have evolved specialized, highly conserved, primary and secondary structural elements to facilitate these types of interactions.Shortly after the discovery that mRNA primary transcripts contain long, non-coding intervening sequences (introns) by Sharp and Roberts, Joan Steitz began work to characterize the biochemical mechanism of intron excision. The curious observation that a sequence found in the 5´ region of the U1 snRNA exhibited extensive base pairing complementarity with conserved sequences across 5´ splice junctions in hnRNA transcripts prompted speculation that certain snRNAs may be involved in recognizing splice site boundaries through RNA:RNA contacts. Only recently have atomic crystal structures revealed demonstrably that the original conjecture was indeed correct, even if the complexity of these interactions were not fully realized at the time.
U2 snRNA Recognition Elements:
In Saccharomyces cerevisiae the U2 snRNA is associated with 18 polypeptides, seven of which are structural proteins common to all Sm class snRNPs. These non-specific structural proteins associate with Sm snRNAs through a highly conserved recognition sequence (AUnG,n = 4-6) located within the RNA called Sm-binding sites. Two other proteins, A´ and B´´, are U2-specific and require structural elements unique to U2 snRNA—specifically two 3´ stem loops—for snRNP assembly. The three-subunit SF3a and six-subunit SF3b protein complexes also associate with the U2 snRNA.U2 snRNA is implicated in intron recognition through a 7-12 nucleotide sequence between 18-40 nucleotides upstream of the 3´ splice site known as the branch point sequence (BPS). In yeast, the consensus BPS is 7 nucleotide residues in length and the complementary recognition sequence within the U2 snRNA is 6 nucleotides. Duplex formation between these two sequences results in bulging of a conserved adenosine residue at position 5 of the BPS. The bulged adenosine residue adopts a C3´-endo conformation that with the help of splicing factors Cwc25, Yju2 and Isy1 aligns a 2´ OH for an inline attack of a phosphorus atom at the 5´ splice site. Nucleophilic attack initiates the first of two successive transesterification reactions that splices out the intron—through an unusual 2´-5´-3´ linked lariat intermediate—where the second transesterification involves ligation of the two flanking exons.
Primary and Secondary Structure:
Although the sequence length of U2 snRNAs can vary by up to an order of magnitude across all eukaryotic organisms, all U2 snRNAs contain many phylogenetically constant regions particularly within the first 80 nucleotides downstream of the 5´ end where 85% of the positions are conserved. Moreover, several secondary structural elements are also conserved including stem loops I, II, III, IV, and some of the single stranded regions linking these domains. Stem loop II in yeast U2 snRNA, contains an unusual sheared GA base pair leading into a characteristic U-turn loop motif that shares a geometric conformation similar to that of tRNA anti-codon loops. All U2 snRNAs possess a terminal stem loop (IV) with a 10-16 base pair helix and a conserved 11 nucleotide loop with the consensus sequence 5´-UYGCANUURYN-3´.U2 snRNAs are the most extensively modified of all the small nuclear RNAs. While the exact locations of these post-transcriptional modifications can vary from organism to organism, emerging evidence suggests there is a strong correlation between U2 snRNA modification and biological function. Modifications include the conversion of some uridine residues to pseudouridine, 2´-O-methylation, nucleobase methylation, and conversion of 5´-monomethylated guanosine cap to a 2,2,7-trimethylated guanosine cap. Many of these modifications reside in a 27-nucleotide region on the 5´ end of the molecule.
Conformational Dynamics:
The spliceosome is a dynamic molecular machine that undergoes several conformational rearrangements throughout assembly and splicing. Although many of the biochemical details surrounding spliceosomal rearrangements remains unclear, recent studies have visualized the formation of a critical folding complex between U2 and U6 snRNAs immediately proceeding the first step of the splicing reaction. This folding event facilitates the formation of a four-helix junction, which is believed to provide scaffolding for the critical components of the active site including aligning the 5´ splice site with the branch point adenosine for inline attack by the 2´ OH and coordinating two Mg2+ ions to stabilize negative charge formation in the proceeding steps.
Evolutionary Origins:
A notable characteristic of the U2-U6 fold is its structural similarity to that of domain V in self-splicing group II introns. The AGC triad found in U6 snRNA is conserved in group II introns and has been found to favor the same tertiary stacking interactions as well. The formation of a GU wobble pair early in the U2-U6 folding event is also observed in the formation of the catalytic core of group II introns. Finally, it is likely the spliceosome utilizes the same two-metal ion mechanism as group II introns given the structural conservation of metal binding sites found within the U2-U6 fold. The extent of both secondary and tertiary structure conservation between group II introns and the U2-U6 fold in the active site of the spliceosome strongly suggests both group II introns and the spliceosome share a common evolutionary origin. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Dead or Alive: Dimensions**
Dead or Alive: Dimensions:
Dead or Alive: Dimensions (Japanese: デッド オア アライブ ディメンションズ, Hepburn: Deddo Oa Araibu Dimenshonzu, abbreviated as DOAD) is a fighting game developed by Team Ninja and released by Tecmo Koei and in some regions by Nintendo for the Nintendo 3DS in 2011. Originally planned as a launch title for the 3DS but delayed due to 2011 Tōhoku earthquake and tsunami, DOAD makes use of the console's unique features. The game was well received by critics.
Dead or Alive: Dimensions:
Dimensions can be considered a compilation game rather than a truly new entry in the Dead or Alive series, similar to the likes of Mortal Kombat Trilogy or Tekken Tag Tournament. It offers 26 playable fighters, more than any previous installment in the franchise, and uses a modified engine of Dead or Alive 4. Its plot compiles the stories of the previous four main DOA games with additional details, focusing on Kasumi for 1, Ryu Hayabusa for 2, Ayane for 3, and Helena Douglas for 4.
Dead or Alive: Dimensions:
Dimensions was the first DOA game to be released on a Nintendo system, the first one not fully published by Tecmo (it was jointly published with Nintendo in Europe and Australia), the first DOA fighting game released on a handheld, and most notably, the first released without any involvement from series creator Tomonobu Itagaki. It was also the first game in the series to have a "Teen" rating from the ESRB since Dead or Alive 3 by toning down the sexual content for female characters; nevertheless, the game was not distributed in Sweden and consequently in all Scandinavia, and experienced problems with being released in Australia as well.
Gameplay:
In Dead or Alive Dimensions, the action is displayed on the top screen of the Nintendo 3DS, while the special fighting moves are displayed on the touch screen below. DOAD incorporates a Chronicle Mode feature, which acts as a story mode in the game, going through all four Dead or Alive tournaments as the player assumes the roles of various fighters from the series. The other modes featured are Arcade (in which the player fights for additional time), Survival (in which the player fights until he defeats all opponents or is knocked out), Free Play, Training, Showcase (in which the player position 3D models on a stage and takes 3D photos of them), and 3D Photo Album (in which the player views the photos taken in Showcase mode).The game's stages are mostly taken from Dead or Alive 3 and Dead or Alive 4 (both stage are also taken from Dead or Alive Ultimate). The substantial new content in the game are the Freedom Survivor stage and the inclusion of a stage based on Metroid: Other M – a Wii game co-developed by Team Ninja with Nintendo – with characters from that game appearing as stage hazards (but not playable fighters). The characters Kasumi Alpha, Genra, and Alpha-152 who were boss characters in the previous games are made playable for the first time as unlockable characters. Shiden, who first appeared in Dead or Alive Ultimate, makes his first playable appearance as an unlockable boss character.
Gameplay:
The 3DS's touch screen is used to make the characters execute special fighting moves, while the top screen is used for displaying the fight, in a similar fashion to Super Street Fighter IV: 3D Edition. Dimensions supports in-game frame data that can be displayed on the bottom screen during Training Mode. Dimensions also uses the 3DS' StreetPass feature to make AI representations of the player, based on their play patterns, that can challenge other owners of the game in the Throwdown mode. Dimensions offers a framerate of 60 frames per second with the console's 3D feature turned off. With it turned on, however, the imagery is divided by two for the players individual eyes (30 frames per second to each eye).
Characters:
Dimensions features a roster of 26 playable characters, including an original character created for the game, Shiden. The list of characters are given below, with unlockable characters marked with an asterisk.
Outside of the playable characters, Ridley from the Metroid series appears as a stage hazard in the "Geothermal Power Plant" stage, while Metroid protagonist Samus Aran makes a cameo appearance in the stage to help the fighters.
Plot:
Dead or Alive: Dimensions plot spans the first four main games in the Dead or Alive series, which also unfold the hidden truth within its stories.
Plot:
In the prologue, set before the first game, Kasumi is confronted by her father, the 17th and current leader of the Mugen Tenshin Ninja Clan, Shiden, about her skills as he plans to make her his next heir. Originally, Kasumi's brother and Shiden's eldest child, Hayate, was destined to be Shiden's next heir, but sometime ago, Kasumi's uncle, the exiled ninja Raidou, attacked the village, beating her half-sister Ayane and defeating her brother Hayate. As a result, Hayate was crippled and fell into a coma. Upon learning this, Kasumi decided to run away from the village to take revenge on Raidou for Hayate, even though it meant she would be a fugitive and likely to be killed by her own clan since leaving without permission is against the ninja code. Kasumi is quickly stopped by Ayane, who was ordered by her foster-father Genra to track her down and kill her, but a woman named Christie appears in a helicopter and saves Kasumi. Although Kasumi did not know the woman, she went with Christie to safety. Heading towards Helena Douglas' cruise ship "Freedom Survivor", Kasumi is introduced to both Christie and Bayman and is told about the "DOA tournament", with Raidou being there. Kasumi encounters Ayane, now a contestant, and both meet Raidou with Fame Douglas, the founder and head of the Dead or Alive Tournament Executive Committee (DOATEC). After Kasumi fights her way and manages to reach the final round, she faces against Raidou and defeats him, but then he reawakens more powerful than before. Kasumi uses her magic against him, and with a little help from fellow ninja, Ryu Hayabusa, she finally kills Raidou. However, she gets kidnapped by DOATEC, which prompts Ryu to save her. That same night, Fame Douglas is assassinated by Bayman with a sniper rifle under the orders of DOATEC's scientist, Victor Donovan, who desires to gain control of the committee to perform genetic projects. Although Bayman is successful in Douglas' assassination, Christie leaves Bayman behind as she returns to DOATEC headquarters.
Plot:
Hayate, still in a coma, is abducted from the village by Kasumi Alpha, an evil clone of Kasumi created by the DOATEC Super-human Development Project. Ayane is told by Genra about the return of Tengu and sent to search for Ryu in Europe. After the death of Helena's father Fame, and then later her mother Maria, Helena appears on Freedom Survivor and takes over the Dead or Alive Tournament Executive Committee. To everyone on board the cruise ship, she announces the "second DOA tournament", with herself participating as a competitor, determined to find the truth about the murder of her parents. Aboard Freedom Survivor, Ryu is approached by a woman named Lisa Hamilton. During Lisa's phone call with Victor Donovan, Ryu overhears that Kasumi is in the DOATEC Germany facility. Ryu's friend, Irene Lew, arrives in a helicopter, and they both head to the facility. In DOATEC's facility in Germany, where Kasumi is indeed being held, Alpha sneaks Kasumi out of her cell and reveals that Hayate is also in the facility. As the facility burns down, Ryu saves Kasumi and takes her to safety, while Lisa and Alpha make their escape with Hayate and place him in one of the helicopters, which gets hit and crashes. In the forest, Ryu and Irene learn that Hayate was experimented on in genetics research in the facility and Kasumi runs off to find him. In another part of the forest, a karateka named Hitomi is training when Hayate, who survived the crash, stumbles into her and collapses. Hitomi then offers to help the unconscious Hayate. Sometime later, as Ryu battles his way through the tournament, he tries to warn competitor, Jann Lee, and other competitors of the dangers of the tournament but finds them unwilling to back down, so he proceeds to knock them out of the tournament. Ryu encounters Hayate, who is now going by the name of "Ein" and suffering from amnesia. Ryu defeats him and restores some parts of his memory. Afterwards, Ryu tracks down Tengu and kills him. Ein arrives at Miyama and tries to remember why he knows the place. After defeating Kasumi in battle and knocking her out, Hayate regained his memories, but Genra reveals that he allowed Tengu to pass into the human world and escapes, leaving a brainwashed Ayane and Kasumi Alpha to fight Ryu and Hayate. Ryu, along with Irene, explain to Hayate that Genra may have been involved with DOATEC, and although Ayane returns to normal, both Kasumi and Alpha disappear.
Plot:
During the "third tournament", Helena hires Bayman to protect her and kill Donovan. Bayman accepted the offer as he also desires to kill Donovan for his attempt to assassinate him. Christie, posing as Helena's assistant, attempts to assassinate her but is caught and restrained by Bayman. Alpha over-hears that Helena wants Donovan dead and attacks her, but Helena manages to defeat her. With Genra turned traitor, Hayate requests to his father that he should hunt him down, making Shiden believe Hayate is ready to take over as the next leader of their clan instead of Kasumi. Hayate wants to bring Kasumi home first, but Ayane speaks against it, calling Kasumi a traitor, which enrages Hayate and makes him slap her. Thinking that Hayate now hates her, Ayane attempts suicide, but is found by her mother, Ayame. Ayane is upset believing Hayate only cares about Kasumi, but Ayame reminded her that all four of them are family and asks Ayane to save Kasumi rather than be her enemy as Ayame believes their family's bonds are stronger than the ninja code. Hayate and Ayane join the third tournament to track down Genra. Kasumi spends some time in the geisha district of Kyoto during her running and disguised herself as a normal high school girl and civilian to get by. She developed a fever and passes out on the road. She is found by local maiko, Kokoro, who offered to help her, but Kasumi refuses. Upon seeing Ayane from a distance, Kasumi panics and flees. Ayane ask Kokoro where the girl fled to, but Kokoro quickly caught on to Kasumi's fright and refused to tell Ayane. Ayane then tried to beat the information out of Kokoro. Hayate arrives shortly after their fight, and Ayane informs him that she saw Kasumi while Kokoro fled the scene. While on Freedom Survivor, Hayate meets up with Hitomi again since his departure from her father's dojo when he was Ein, and Hayate tells Hitomi the truth about his and Ayane's ninja identities, much to Hitomi's surprise. Later, Hayate and Ayane come across xinyi-liuhe-quan master Gen Fu, who is giving his apprentice, Eliot, rigorous training. Gen Fu then asks the two ninjas for a friendly tag duel so that his apprentice can experience different fighting styles. After the fight, Eliot proclaims that he is still inexperienced and not yet ready to succeed Gen Fu as xing-yi-quan master. An annoyed Ayane slaps Eliot and tells him to stop putting himself down and toughen up. Eliot thanks her for the advice and they all hope that they can meet each other again. Sometime later, while Hayate and Hitomi were training in Freedom Survivor, they were interrupted by competitor Leifang's crash by Jann Lee. Hitomi steps in to defend Leifang from Jann Lee, but Leifang tells Hitomi to stay out of it therefore starting their rivalry. Jann Lee thinks Hayate is a worthy competitor and asks him for a fight. Sometime later, Hayate meets with Helena, who recognizes him as the subject of Project Epsilon. Hayate demands her to tell him why Genra joined DOATEC, but she claimed she does not know and both Genra and herself are just puppets of DOATEC. After defeating Helena in battle, he tells her that she should leave DOATEC for her own safety. Later, Hayate and Ayane meet up with Ryu and Irene, but Irene gets kidnapped by Christie. Ryu runs off to save her, while Hayate and Ayane are confronted by Genra, who acquired a transformation into his Omega form. When Ryu realizes that Christie was just a decoy, he returns to aid them, and runs Omega-powered Genra through with his Dragon Sword, giving time for Ayane and Hayate to perform a duel magic attack that strikes Genra before he could regenerate, killing him. When they return to the village, Ayane watches Genra's body cremated as she walks away in tears.
Plot:
After Helena became head leader of DOATEC, Donovan discusses with her the biological weapon cloning project, Project Alpha. With the "fourth tournament" on the way, Hayate and the forces of the Mugen Tenshin clan are planning an assault on DOATEC's main headquarters, the Tri-Tower. Fearing the worst, Kasumi finds her brother and tries to convince him not to start a war, but the plea falls on deaf ears. One night, Hayate, Ayane, and Ryu attacks the Tri-Tower with Irene and the CIA aiding them. Inside the tower, Ayane and Ryu are intercepted by Christie. Ayane engages Christie in combat while Ryu tries to regroup with Hayate. At the same time, Kasumi infiltrates the Tri-Tower and confronts Helena, pleading with her to stop the war, but Helena replied that the ninjas would stop at nothing to destroy DOATEC, and the final product of Project Alpha, Alpha-152. Helena attempts to shoot Kasumi with a handgun, but she is saved by Ryu. Hayate is approached by Lisa Hamilton, now a luchadora going by her ring name "La Mariposa". She reveals that she had something to do with his vendetta against DOATEC. Hayate merely replied that she had done him a favor and repaid her with a fight. Afterwards, Hayate meets with Hitomi again, who pleaded for him to come back with him to the dojo. Hayate told her that he couldn't, and the fourth tournament was no tournament at all, but a war between DOATEC and his people. He then asked her to spar for a warm-up, for old time's sake, which she happily accepted. After the fight, they told each other to take care before Hitomi departs. While Kasumi makes her way to fight an awakened Alpha-152, Hayate and Ayane use their magic to destroy the Tri-Tower, only to have to face Alpha-152 themselves. With the Tri-Tower in flames, Helena faces Christie one last time, and learns that it was actually her who killed her mother Maria. After finding out the truth, Helena sets off the building's self-destruction and plans to end her own life, with Kasumi and Ayane helplessly watching from afar. However, she is suddenly saved by Zack, who sweeps in by helicopter and pulls her to safety. The final scene shows Donovan taking off his white mask, and putting on Genra's mask.
Development and release:
Dead or Alive: Dimensions was first revealed as an official title on June 15, 2010 at E3 under the working title Dead or Alive 3D. Dimensions is the fourth Dead or Alive game to feature English voice overs; most of voice actors have been recast. Yosuke Hayashi took over as the director and producer following the departure of the series' creator Tomonobu Itagaki.
Development and release:
DOAD was scheduled for release at the Nintendo 3DS launch on February 26, 2011. However, due to the 2011 Tōhoku earthquake and tsunami of March 11, the release was pushed back by two months. It was eventually released on May 19 in Japan (by Tecmo Koei), on May 20 in Europe (by Nintendo), on May 24 in North America (by Tecmo Koei), and on May 26 in Australia (by Nintendo).
Reception:
Reviews Dead or Alive: Dimensions had consistently favourable reviews. It earned an aggregated score 79/100 at Metacritic.Nintendo Power review praised the "top-notch" cutscenes and the "fast and furious as ever" gameplay, but warned against the 3D effect, as well as having problems with the Tag Mode feature. According to VideoGamer.com, "the Street Pass feature is nice and the controls work well, but the framerate suffers online, and the Chronicle Mode is a narrative mess." GameZone opined that "loads of modes, plenty of unlockable extra goodies, and a very functional multiplayer make Dimensions a series that not only fans must buy, but any gamer with even the slightest itch for a quality portable fighting game. If you’ve been waiting for the next must-buy 3DS title, this is it, folks." Controversy Due to a Swedish controversy, Dead or Alive: Dimensions is not being sold in Sweden, Norway, and Denmark. The concerns were raised when an internet forum user commented that three underage characters in the game could be viewed from angles that could be considered lascivious.Concerns in relation to the game also rose in Australia, when certain media outlets criticized the PG rating for the game. After careful consideration, the Australian Classification Board came to the conclusion that it was not given sufficient information at the time to give it a correct classification. The game's PG rating was subsequently revoked. Nintendo has then resubmitted the game with a more detailed analysis of the game's content. The game was subsequently given the next rating after PG, the M rating, which allows any age to still purchase the game, but is recommended for more mature audiences. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Continuous wound infiltration**
Continuous wound infiltration:
Continuous wound infiltration (CWI) refers to the continuous infiltration of a local anesthetic into a surgical wound to aid in pain management during post-operative recovery.
History:
Continuous wound infiltration first appeared on the market in the late 1990s when a US company (I-Flow Corporation) found a way to evenly spread and continuously infiltrate a local anesthetic, via a specially designed multi holed catheter, inside the wound, to enable post-operative pain treatment.
The benefits of wound infiltration are quite prominent which is the reason why "single shot" wound infiltration had already been done for several decades. The limiting factor of the single shot approach has always been the half-life period of the local anesthetics which would not allow a long term post-op pain treatment.
Technique:
A local anesthetic is administered into the wound with a specially designed, multi-holed catheter. The catheter allows for even spread throughout the entire area of the wound, depending on the size of the catheter.
Technique:
The surgeon places the catheter during surgery shortly before closing the surgical incision. For best catheter placement and nerve blockage, the catheter must be located as close as possible to the nerve. Tunneling should be applied if a distal infiltration of the adjacent nerve root is preferred.For thoracic and abdominal surgeries, the surgeon will place the catheter superior to the respective fascias. For thoracic surgeries, the catheter goes superior to the pleura. For all type of abdominal surgeries the catheter should be close to the peritoneum. A recent systematic review showed that deep wound catheters (placed pre-peritoneally or in the transversus abdominis plane), provide better pain control than subcutaneous wound catheters after abdominal surgery.After being placed, the catheter is connected to an elastomeric pump that ensures a constant delivery of the anesthetic and also serves as the drug container. Depending on the flow rate and the pump size, one pump can provide continuous wound infiltration for several days.
Outcomes:
CWI is considered as an effective alternative to other regional anesthetic techniques such as peripheral nerve blocks and spinal-epidural anesthesia. It is especially applicable where those techniques are contra-indicated, such as in patients using potent coagulants.
Outcomes:
Besides, some patients might prefer an alternative to epidural analgesia because of epidural-related side effects. Epidural analgesia may lead to serious neurological complications (epidural haematoma and abscess, with an incidence of one in 1000–6000 for thoracic epidurals) and need for preoperative placement in awake patients, considered as cumbersome by many patients, sometimes leading to refusal.The outcome in most cases is beneficial for the patient because of a faster return to normal body functions, less pain, faster rehabilitation and less side effects. CWI offers the opportunity to significantly minimize the use of narcotics during post-op pain management and reduces the side-effects (post-operative nausea and vomiting) that come with opioids. Also, CWI has been shown to provide more excellent satisfaction scores compared to alternatives. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Morsicatio buccarum**
Morsicatio buccarum:
Morsicatio buccarum is a condition characterized by chronic irritation or injury to the buccal mucosa (the lining of the inside of the cheek within the mouth), caused by repetitive chewing, biting or nibbling.
Signs and symptoms:
The lesions are located on the mucosa, usually bilaterally in the central part of the anterior buccal mucosa and along the level of the occlusal plane (the level at which the upper and lower teeth meet). Sometimes the tongue or the labial mucosa (the inside lining of the lips) is affected by a similarly produced lesion, termed morsicatio linguarum and morsicatio labiorum respectively. There may be a coexistent linea alba, which corresponds to the occlusal plane, or crenated tongue. The lesions are white with thickening and shredding of mucosa commonly combined with intervening zones of erythema (redness) or ulceration. The surface is irregular, and people may occasionally have loose sections of mucosa that comes away.
Causes:
The cause is chronic parafunctional activity of the masticatory system, which produces frictional, crushing and incisive damage to the mucosal surface and over time the characteristic lesions develop. Most people are aware of a cheek chewing habit, although it may be performed subconsciously. Sometimes poorly constructed prosthetic teeth may be the cause if the original bite is altered. Usually the teeth are placed too far facially (i.e. buccally and/or labially), outside the "neutral zone", which is the term for the area where the dental arch is usually situated, where lateral forces between the tongue and cheek musculature are in balance. Glassblowing involves chronic suction and may produce similar irritation of the buccal mucosa. Identical, or more severe damage may be caused by self-mutilation in people with psychiatric disorders, learning disabilities or rare syndromes (e.g. Lesch–Nyhan syndrome and familial dysautonomia).
Diagnosis:
The diagnosis is usually made on the clinical appearance alone, and biopsy is not usually indicated. The histologic appearance is one of marked hyperparakeratosis producing a ragged surface with many projections of keratin. Typically there is superficial colonization by bacteria. There may be vacuolated cells in the upper portion of the prickle cell layer. There is a similarity between this appearance and that of hairy leukoplakia, linea alba and leukoedema. In people with human immunodeficiency virus, who are at higher risk of oral hairy leukoplakia, a tissue biopsy may be required to differentiate between this and frictional keratosis from cheek and tongue chewing.
Diagnosis:
Classification Morsicatio buccarum is a type of frictional keratosis. The term is derived from the Latin words, morusus meaning "bite" and bucca meaning "cheek". This term has been described as "a classic example of medical terminology gone astray".The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) classifies the condition under "Other Specified Obsessive-Compulsive and Related Disorder" (300.3) as a body-focused repetitive behavior; the DSM-5 uses the more descriptive terms lip biting and cheek chewing (p. 263) instead of morsicatio buccarum.
Treatment:
The lesions are harmless, and no treatment is indicated beyond reassurance, unless the person requests it. The most common and simple treatment is construction of a specially made acrylic prosthesis that covers the biting surfaces of the teeth and protects the cheek, tongue and labial mucosa (an occlusal splint). This is either employed in the short term as a habit breaking intention, or more permanently (e.g. wearing the prosthesis each night during sleep). Psychological intervention has also been attempted, with some studies reporting negative findings, while some individuals seem to benefit from behavioral procedures involving habit reversal training and decoupling.
Epidemiology:
This phenomenon is fairly common, with one in every 800 adults showing evidence of active lesions at any one time. It is more common in people who are experiencing stress or psychological conditions. The prevalence in females is double the prevalence in males, and it is two or three times more prevalent in people over the age of thirty-five. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
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