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The Pelagornithidae had extremely thin-walled bones widely pneumatized with the air sac extensions of the lungs. Most limb bone fossils are very much crushed for that reason. In life, the thin bones and extensive pneumatization enabled the birds to achieve large size while remaining below critical wing loadings. Though... | Pelagornithidae | Wikipedia | 436 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Altogether, almost no major body part of pelagornithids is known from a well-preserved associated fossil and most well-preserved material consists of single bones only; on the other hand the long occurrence and large size makes for a few rather comprehensive (though much crushed and distorted) remains of individual bir... | Pelagornithidae | Wikipedia | 225 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Unlike the true teeth of Mesozoic stem-birds like Archaeopteryx or Ichthyornis, the pseudoteeth of the pelagornithids do not seem to have had serrated or otherwise specialized cutting edges, and were useful to hold prey for swallowing whole rather than to tear bits off it. Since the teeth were hollow or at best full of... | Pelagornithidae | Wikipedia | 478 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
It is sometimes claimed that as with some other seabirds (e.g. the flightless Plotopteridae), the evolutionary radiation of cetaceans and pinnipeds outcompeted the pseudotooth birds and drove them into extinction. While this may be correct for the plotopterids, for pelagornithids it is not so likely for two reasons: Fi... | Pelagornithidae | Wikipedia | 329 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Thus, direct competition for food between bony-toothed birds and cetaceans or pinnipeds cannot have been very severe. As both the birds and pinnipeds would need level ground near the sea to raise their young, competition for breeding grounds may have affected the birds' population. In that respect, the specializations ... | Pelagornithidae | Wikipedia | 469 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
There is no obvious single reason for the pseudotooth birds' extinction. A scenario of general ecological change – exacerbated by the beginning ice age and changes in ocean currents due to plate tectonic shifts (e.g. the emergence of the Antarctic circumpolar current or the closing of the Isthmus of Panama) – is more l... | Pelagornithidae | Wikipedia | 381 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Irrespective of the cause of their ultimate extinction, during the long time of their existence the pseudotooth birds furnished prey for large predators themselves. Few if any birds that coexisted with them were large enough to harm them while airborne; as evidenced by the Early Eocene Limnofregata, the frigatebirds co... | Pelagornithidae | Wikipedia | 396 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Nothing is known for sure about the colouration of these birds, as they left no living descendants. But some inferences can be made based on their phylogeny: if they were a member of the "higher waterbird" group (see below), they most probably had a plumage similar to that depicted in the reconstruction of Osteodontorn... | Pelagornithidae | Wikipedia | 212 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
If the pseudotooth birds are Galloanseres, phaeomelanins might be more likely to have occurred in their feathers, but it is notable that the most basal lineages of Anseriformes are typically grey-and-black or black-and-white. Among ocean-going birds in general, the upperside tends to be much darker than the underside (... | Pelagornithidae | Wikipedia | 511 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Historically, the disparate bones of the pseudotooth birds were spread across six groups: a number of genera described from leg bones was placed in a family Cyphornithidae, and considered close allies of the pelican family (Pelecanidae). They were united with the latter in a superfamily Pelecanides in suborder Pelecana... | Pelagornithidae | Wikipedia | 496 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Systematics and phylogeny
The systematics of bony-toothed birds are subject of considerable debate. Initially, they were allied with the (then-polyphyletic) "Pelecaniformes" (pelicans and presumed allies, such as gannets and frigatebirds) and the Procellariiformes (tube-nosed seabirds like albatrosses and petrels), be... | Pelagornithidae | Wikipedia | 291 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
In 2005, a cladistic analysis proposed a close relationship between pseudotooth birds and waterfowl (Anseriformes). These are not part of the "higher waterbirds" but of the Galloanserae, a basal lineage of neognath birds. Some features, mainly of the skull, support this hypothesis. For example, the pelagornithids lack ... | Pelagornithidae | Wikipedia | 286 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
As regards other parts of the skeleton, the proposed synapomorphies of pelagornithids and waterfowl are found mainly in the arm- and handbones: the ulna had a strongly convex upper backside at its elbow end – at the handward end of which the scapulotricipital muscles attached –, a point-tipped dorsal cotyle and only a ... | Pelagornithidae | Wikipedia | 426 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
It is unclear what to make of these apomorphies supposedly uniting Anseriformes and bony-toothed birds, for on the other hand, the sternum, distal humerus, leg and foot bones of pelagornithids seem to show apomorphies typical of "higher waterbirds". While details of the braincase bones are held to be very informative p... | Pelagornithidae | Wikipedia | 457 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
While giant Galloanserae were common and diverse in the Paleogene in particular, these (Gastornis and mihirungs) were flightless terrestrial birds; it is perhaps significant though that the only other "bone-toothed" birds known so far are the two species of the moa-nalo genus Thambetochen, extinct giant flightless dabb... | Pelagornithidae | Wikipedia | 294 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
As their relationships are still unresolved between Galloanserae and "higher waterbirds", the pseudotooth birds are here placed in the distinct order Odontopterygiformes as a compromise, rather than in a pelecaniform/ciconiiform or anseriform suborder Odontopterygia or even a family of the Anseriformes, Ciconiiformes o... | Pelagornithidae | Wikipedia | 459 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
While the authors claim it is beyond the paper's scope, the study describing Protodontopteryx suggests that the proposed pro-galloansere traits might actually be plesiomorphic in relation to Aves. It also notes "striking" similarities between pelagornithids and Ichthyornis in terms of jaw anatomy, but still classifies ... | Pelagornithidae | Wikipedia | 474 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Tentatively, the following genera are recognized:
Protodontopteryx (Early Paleocene of New Zealand)
Pseudodontornis (Late Paleocene ?–? Late Oligocene of Charleston, South Carolina, US) – polyphyletic (type species in Palaeochenoides/Pelagornis)?
"Odontoptila" (Late Paleocene/Early Eocene of Ouled Abdoun Basin, Moro... | Pelagornithidae | Wikipedia | 508 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
Pelagornithidae gen. et sp. indet. (Late Eocene of Kazakhstan) – may belong in Zheroia
Pelagornithidae gen. et sp. indet. (Eocene of South Shetland Islands, South Atlantic)
cf. Dasornis (Late Eocene/Early Oligocene of Oregon, US) – Cyphornis?
cf. Macrodontopteryx (Early Oligocene of Hamstead, England) – may belong i... | Pelagornithidae | Wikipedia | 494 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
"Pseudodontornis" stirtoni (Miocene or Pliocene of Motunau Beach, New Zealand) – sometimes Neodontornis
Pelagornithidae gen. et sp. indet. (Yushima Early Pliocene of Maesawa, Japan) – Osteodontornis?
cf. "Pseudodontornis" stirtoni (Tangahoe Mudstone Middle Pliocene of Hawera New Zealand)
Pelagornithidae gen. et sp. ... | Pelagornithidae | Wikipedia | 243 | 9205088 | https://en.wikipedia.org/wiki/Pelagornithidae | Biology and health sciences | Prehistoric birds | Animals | vital_articles |
The Astronomical Almanac is an almanac published by the United Kingdom Hydrographic Office; it also includes data supplied by many scientists from around the world. On page vii, the listed major contributors to its various Sections are: H.M Nautical Almanac Office, United Kingdom Hydrographic Office; the Nautical Alman... | Astronomical Almanac | Wikipedia | 495 | 7082456 | https://en.wikipedia.org/wiki/Astronomical%20Almanac | Technology | Astronomical technology | null | vital_articles |
Section C SUN; covers detailed positional information on the Sun, including the ecliptic and equatorial coordinates, physical ephemerides, geocentric rectangular coordinates, times of transit, and the equation of time.
Section D MOON: contains detailed positional information on the Moon including phases, mean elements... | Astronomical Almanac | Wikipedia | 502 | 7082456 | https://en.wikipedia.org/wiki/Astronomical%20Almanac | Technology | Astronomical technology | null | vital_articles |
Publication history
The Astronomical Almanac is the direct descendant of the British and American navigational almanacs. The British Nautical Almanac and Astronomical Ephemeris had been published since 1766, and was renamed The Astronomical Ephemeris in 1960. The American Ephemeris and Nautical Almanac had been publish... | Astronomical Almanac | Wikipedia | 187 | 7082456 | https://en.wikipedia.org/wiki/Astronomical%20Almanac | Technology | Astronomical technology | null | vital_articles |
In fluid mechanics, Kelvin's circulation theorem states:In a barotropic, ideal fluid with conservative body forces, the circulation around a closed curve (which encloses the same fluid elements) moving with the fluid remains constant with time.
The theorem is named after William Thomson, 1st Baron Kelvin who published... | Kelvin's circulation theorem | Wikipedia | 504 | 7086534 | https://en.wikipedia.org/wiki/Kelvin%27s%20circulation%20theorem | Physical sciences | Fluid mechanics | Physics | vital_articles |
Here is the position of the area of fluid. From Stokes' theorem, this is:
The vorticity of a velocity field in fluid dynamics is defined by:
Then: | Kelvin's circulation theorem | Wikipedia | 35 | 7086534 | https://en.wikipedia.org/wiki/Kelvin%27s%20circulation%20theorem | Physical sciences | Fluid mechanics | Physics | vital_articles |
The Limousin, , is a French breed of beef cattle from the Limousin and Marche regions of France. It was formerly used mainly as a draught animal, but in modern times is reared for beef. A herd-book was established in France in 1886. With the mechanisation of agriculture in the twentieth century, numbers declined. In th... | Limousin cattle | Wikipedia | 458 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
At the beginning of the 19th century, the Limousin region was characterised by the mediocrity of its animals. Texier-Olivier Louis, prefect of the Haute-Vienne, observed that Limousin cattle weighed 300 to 350 kg and measured 1.5 m at the withers. The defect was considered to be attributable to poor genetics, nutrition... | Limousin cattle | Wikipedia | 406 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
The results were not immediate. In 1862, cattle sold at La Souterraine weighed about 600 kg. The decline of Anglomania in favour of economic pragmatism, and the criticism and fall of the aristocracy aided the development of Limousin cattle. The crowning moment was the honour received by the bull Achilles Caillaud to op... | Limousin cattle | Wikipedia | 478 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
One historian reported that the Limousin breed's origins can be traced to the blonde Garonne breed in the fifth century AD. The Garonne breed from the south-west of France was merged into the Blonde d'Aquitaine breed in 1962. The grey Gasconne breed with which Limousin cattle have a close genetic relationship is also r... | Limousin cattle | Wikipedia | 446 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
A less pure form of Limousin is bred up (also known as graded up) from a base animal over a defined number of generations. A parent of each generation's progeny must be registered as a Limousin in the respective country's herd book. In the US, Canada, Australia, and New Zealand, a graded up Limousin, after three genera... | Limousin cattle | Wikipedia | 475 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
July 2007 to June 2008
EU legislation, pressure from French breeders of polled stock, and other developments, including requirements of European Limousin associations (the 11 countries of EUROLIM), contributed to a restructuring of the herd-book that commenced in July 2007.
During the period July 2007 to June 2008, th... | Limousin cattle | Wikipedia | 439 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Base animals selected for the two-stage grading up process to any EU herd book purebred class require a minimum of 3/4 Limousin content. Graded up females using the two-stage process then become eligible for entry into the main section of all EU herd book purebred classes as initial registration (or T.I.) Limousins whe... | Limousin cattle | Wikipedia | 506 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Immediately prior to the restructuring of the herd-book in 2008, French breeders had two months to nominate the class (Pureblood or Purebred) in which they wanted their cattle to be registered. Pureblood cattle have higher business value than Purebreds because they are preferred by French breeders. Also, Full French ca... | Limousin cattle | Wikipedia | 447 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Characteristics considered unacceptable in the French breed standard:
Any pigmentation or black spots on muzzle, black or white hairs anywhere on the coat, particularly in the ears, at the end of the tail and around the muzzle.
White hairs anywhere.
An eliminating count of less than five for any of the different breed ... | Limousin cattle | Wikipedia | 470 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
All females recorded in the French Herd Book are controlled under this system, which focuses mainly on maternal qualities derived from measurements of calving ease, and growth and structure of calves. Females that achieve the best indexes for particular traits are then examined in detail by HBL technicians who assign g... | Limousin cattle | Wikipedia | 501 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
The best bulls go to artificial insemination (AI) cooperatives where semen is taken. AI allows the wide distribution of a bulls' genetics to the benefit of more farmers. However, in order to guarantee their genetic qualities, the bulls are subject to a strict selection scheme to increase the accuracy of the different g... | Limousin cattle | Wikipedia | 429 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
VS – awarded to sires recognised or recommended for weaner production.
VB – awarded to AI sires recognised or recommended for vealer production.
JB – awarded to AI sires recognised or recommended for general beef production.
QM – awarded to AI sires recognised or recommended for breeding stock production.
M – awarded t... | Limousin cattle | Wikipedia | 385 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
A Limousin/Jersey backcross study conducted in Australia and New Zealand to investigate the effects of the F94L myostatin variant concluded that the mutation had no significant effect on birth-weight and growth traits. Averaged over all backcross calves in the trial (total of 766), animals homozygous for the mutation h... | Limousin cattle | Wikipedia | 469 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Britain
British test results of sale bulls in February 2010 indicated that of 142 animals tested, just under 90% were homozygous for the F94L mutation, about 8.5% were heterozygous, and 1.5% did not have the mutation.
USA
Test results of approximately 1,100 cattle recorded in the North American Limousin Foundation her... | Limousin cattle | Wikipedia | 340 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Inconsistent inheritance of myostatin mutations (for example, F94L in Limousins, nt821 in Angus, and Q204X in Charolais) by progeny is expected to result in possible BLUP prediction errors for EBVs and EPDs equalling or exceeding worst case standard errors of prediction. For example, average rib eye area for Limousins ... | Limousin cattle | Wikipedia | 402 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Comparisons with other breeds
A USMARC long-term multi-breed study of Limousins, three British (Red Poll, Hereford, Aberdeen Angus) and five other continental European (Braunvieh, Pinzgauer, Gelbvieh, Simmental, Charolais) cattle breeds reported that Limousin cattle were the most efficient and fastest of all breeds at ... | Limousin cattle | Wikipedia | 436 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
For a market end point of 333 kg carcase weight, the Limousin carcases in the USMARC study were estimated to be on average 63.5% of live weight, compared with an average 59.7% (range 58.6% – 60.4%) for the eight other breeds. Similar figures for Limousin meat yield are reported in other sources.
The USMARC study indic... | Limousin cattle | Wikipedia | 487 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Live weight and daily live weight gain are the simplest and most common of all traits to be measured and reported, which continues to mask Limousin's superior saleable meat production efficiency.
Breed differences are expected to have reduced since the USMARC studies in the 1980s and 1990s because of the wide-scale in... | Limousin cattle | Wikipedia | 471 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Crossbred cows produce up to, and in some cases in excess of, 20% more weaned calf weight as a result of increased reproductive performance and maternal ability. Crossbred cow longevity is also increased by up to two years when compared with straightbred cows. However, the benefits of hybrid vigour in a crossbred cow d... | Limousin cattle | Wikipedia | 512 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
A third form of progeny arises when F1 hybrids are bred with animals genetically dissimilar to their parents. If heterozygosity is maintained or increased as a result, hybrid vigour and other production benefits occurring in the F1 generation will be maintained or increased. Maintenance of heterozygosity is the key to ... | Limousin cattle | Wikipedia | 512 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
The first Brahmousin cattle were produced from a multiple embryo transfer from a French-imported Limousin dam. The resulting progeny were then crossed with Brahman cattle to achieve an F1 hybrid. Further crosses over a broader base led to the production of the 5/8 Limousin – 3/8 Brahman Brahmousin purebred, a mix which... | Limousin cattle | Wikipedia | 453 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
The Lim-Flex certification mark has been adopted in Australia and New Zealand, where "commercial Lim-Flex must be 25 to 75 percent Limousin and 25 to 75 percent Angus or Red Angus", and in Canada, where they "must be 37.5 to 75 percent Limousin and 25 to 62.5 percent Angus or Red Angus, with a maximum allowance of anot... | Limousin cattle | Wikipedia | 303 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Initial exports
Following the creation of the French Limousin Herd-Book in 1886, Limousins were exported to Brazil (1886), New Caledonia (1902), Uruguay (1910), Madagascar (1922), Argentina (1924), and Portugal (1929). However, the only herd that became established outside France during this period was in New Caledonia... | Limousin cattle | Wikipedia | 456 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Limousins in different countries are bred according to different selection practices or objectives, and are connected by limited international gene flows. Poor genetic connectedness between countries has negative implications for estimation accuracies of international genetic prediction programmes. As a result of genet... | Limousin cattle | Wikipedia | 280 | 2953081 | https://en.wikipedia.org/wiki/Limousin%20cattle | Biology and health sciences | Cattle | Animals | vital_articles |
Food groups categorise foods for educational purposes, usually grouping together foods with similar nutritional properties or biological classifications. Food groups are often used in nutrition guides, although the number of groups used can vary widely.
Food groups were a public health education concept invented to te... | Food group | Wikipedia | 461 | 2953473 | https://en.wikipedia.org/wiki/Food%20group | Biology and health sciences | Health and fitness | null | vital_articles |
The most common food groups
Dairy, also called milk products and sometimes categorized with milk alternatives or meat, is typically a smaller category in nutrition guides, if present at all, and is sometimes listed apart from other food groups. Examples of dairy products include milk, butter, ghee, yogurt, cheese, cre... | Food group | Wikipedia | 466 | 2953473 | https://en.wikipedia.org/wiki/Food%20group | Biology and health sciences | Health and fitness | null | vital_articles |
Water is treated in very different ways by different food guides. Some exclude the category, others list it separately from other food groups, and yet others make it the center or foundation of the guide. Water is sometimes categorized with tea, fruit juice, vegetable juice and even soup, and is typically recommended i... | Food group | Wikipedia | 65 | 2953473 | https://en.wikipedia.org/wiki/Food%20group | Biology and health sciences | Health and fitness | null | vital_articles |
Uncommon food groups
The number of "common" food groups varies depending on who is defining them. Canada's Food Guide, which has been in continual publication since 1942 and is the second most requested government document after the income tax form in Canada, recognizes only four official food groups, listing the remai... | Food group | Wikipedia | 66 | 2953473 | https://en.wikipedia.org/wiki/Food%20group | Biology and health sciences | Health and fitness | null | vital_articles |
Ethylenediamine (abbreviated as en when a ligand) is the organic compound with the formula C2H4(NH2)2. This colorless liquid with an ammonia-like odor is a basic amine. It is a widely used building block in chemical synthesis, with approximately 500,000 tonnes produced in 1998. Ethylenediamine is the first member of th... | Ethylenediamine | Wikipedia | 388 | 2955396 | https://en.wikipedia.org/wiki/Ethylenediamine | Physical sciences | Amides and amines | Chemistry | vital_articles |
Precursor to chelation agents, drugs, and agrochemicals
A most prominent derivative of ethylenediamine is the chelating agent EDTA, which is derived from ethylenediamine via a Strecker synthesis involving cyanide and formaldehyde. Hydroxyethylethylenediamine is another commercially significant chelating agent. Numero... | Ethylenediamine | Wikipedia | 475 | 2955396 | https://en.wikipedia.org/wiki/Ethylenediamine | Physical sciences | Amides and amines | Chemistry | vital_articles |
Tetraacetylethylenediamine
The bleaching activator tetraacetylethylenediamine is generated from ethylenediamine. The derivative N,N-ethylenebis(stearamide) (EBS) is a commercially significant mold-release agent and a surfactant in gasoline and motor oil.
Other applications
as a solvent, it is miscible with polar solve... | Ethylenediamine | Wikipedia | 477 | 2955396 | https://en.wikipedia.org/wiki/Ethylenediamine | Physical sciences | Amides and amines | Chemistry | vital_articles |
Safety
Ethylenediamine, like ammonia and other low-molecular weight amines, is a skin and respiratory irritant. Unless tightly contained, liquid ethylenediamine will release toxic and irritating vapors into its surroundings, especially on heating. The vapors absorb moisture from humid air to form a characteristic white... | Ethylenediamine | Wikipedia | 82 | 2955396 | https://en.wikipedia.org/wiki/Ethylenediamine | Physical sciences | Amides and amines | Chemistry | vital_articles |
Glomeromycota (often referred to as glomeromycetes, as they include only one class, Glomeromycetes) are one of eight currently recognized divisions within the kingdom Fungi, with approximately 230 described species. Members of the Glomeromycota form arbuscular mycorrhizas (AMs) with the thalli of bryophytes and the roo... | Glomeromycota | Wikipedia | 437 | 2955810 | https://en.wikipedia.org/wiki/Glomeromycota | Biology and health sciences | Basics | Plants | vital_articles |
Colonization
New colonization of AM fungi largely depends on the amount of inoculum present in the soil. Although pre-existing hyphae and infected root fragments have been shown to colonize the roots of a host successfully, germinating spores are considered to be the key players in new host establishment. Spores are c... | Glomeromycota | Wikipedia | 406 | 2955810 | https://en.wikipedia.org/wiki/Glomeromycota | Biology and health sciences | Basics | Plants | vital_articles |
Phylogeny
Initial studies of the Glomeromycota were based on the morphology of soil-borne sporocarps (spore clusters) found in or near colonized plant roots. Distinguishing features such as wall morphologies, size, shape, color, hyphal attachment and reaction to staining compounds allowed a phylogeny to be constructed... | Glomeromycota | Wikipedia | 354 | 2955810 | https://en.wikipedia.org/wiki/Glomeromycota | Biology and health sciences | Basics | Plants | vital_articles |
Molecular biology
The biochemical and genetic characterization of the Glomeromycota has been hindered by their biotrophic nature, which impedes laboratory culturing. This obstacle was eventually surpassed with the use of root cultures and, most recently, a method which applies sequencing of single nucleus from spores ... | Glomeromycota | Wikipedia | 214 | 2955810 | https://en.wikipedia.org/wiki/Glomeromycota | Biology and health sciences | Basics | Plants | vital_articles |
The foot per second (plural feet per second) is a unit of both speed (scalar) and velocity (vector quantity, which includes direction). It expresses the distance in feet (ft) traveled or displaced, divided by the time in seconds (s). The corresponding unit in the International System of Units (SI) is the meter per seco... | Foot per second | Wikipedia | 91 | 2956372 | https://en.wikipedia.org/wiki/Foot%20per%20second | Physical sciences | Speed | Basics and measurement | vital_articles |
Heaviside–Lorentz units (or Lorentz–Heaviside units) constitute a system of units and quantities that extends the CGS with a particular set of equations that defines electromagnetic quantities, named for Oliver Heaviside and Hendrik Antoon Lorentz. They share with the CGS-Gaussian system that the electric constant and... | Heaviside–Lorentz units | Wikipedia | 497 | 4061767 | https://en.wikipedia.org/wiki/Heaviside%E2%80%93Lorentz%20units | Physical sciences | Measurement systems | Basics and measurement | vital_articles |
As in the Gaussian system (), the Heaviside–Lorentz system () uses the length–mass–time dimensions. This means that all of the units of electric and magnetic quantities are expressible in terms of the units of the base quantities length, time and mass.
Coulomb's equation, used to define charge in these systems, is in... | Heaviside–Lorentz units | Wikipedia | 506 | 4061767 | https://en.wikipedia.org/wiki/Heaviside%E2%80%93Lorentz%20units | Physical sciences | Measurement systems | Basics and measurement | vital_articles |
Note that The quantities , and are dimensionless, and they have the same numeric value. By contrast, the electric susceptibility is dimensionless in all the systems, but has for the same material:
The same statements apply for the corresponding magnetic quantities.
Advantages and disadvantages of Heaviside–Lorent... | Heaviside–Lorentz units | Wikipedia | 436 | 4061767 | https://en.wikipedia.org/wiki/Heaviside%E2%80%93Lorentz%20units | Physical sciences | Measurement systems | Basics and measurement | vital_articles |
Despite Heaviside's urgings, it proved difficult to persuade people to switch from the established units. He believed that if the units were changed, "[o]ld style instruments would very soon be in a minority, and then disappear ...". Persuading people to switch was already difficult in 1893, and in the meanwhile there ... | Heaviside–Lorentz units | Wikipedia | 486 | 4061767 | https://en.wikipedia.org/wiki/Heaviside%E2%80%93Lorentz%20units | Physical sciences | Measurement systems | Basics and measurement | vital_articles |
Mudskippers are any of the 23 extant species of amphibious fish from the subfamily Oxudercinae of the goby family Oxudercidae. They are known for their unusual body shapes, preferences for semiaquatic habitats, limited terrestrial locomotion and jumping, and the ability to survive prolonged periods of time both in and ... | Mudskipper | Wikipedia | 452 | 4063480 | https://en.wikipedia.org/wiki/Mudskipper | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
Behaviour
Mudskippers typically live in burrows in intertidal habitats, and exhibit unique adaptations to this environment that are not found in most intertidal fishes, which typically survive the retreat of the tide by hiding under wet seaweed or in tide pools. These burrows are most often characterised by their smoot... | Mudskipper | Wikipedia | 435 | 4063480 | https://en.wikipedia.org/wiki/Mudskipper | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
Mudskippers have the ability to breathe through their skin and the lining of their mouth (the mucosa) and throat (the pharynx); this is only possible when the mudskippers are wet, limiting them to humid habitats and requiring that they keep themselves moist. The ability to breathe through their skin is associated with ... | Mudskipper | Wikipedia | 378 | 4063480 | https://en.wikipedia.org/wiki/Mudskipper | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
Blinking
Mudskippers evolved the ability to blink independently from terrestrial tetrapods. Their eyes are located high on their head compared to other gobies, and they blink by lowering their eyes as a membrane called the dermal cup rises to cover them. Although other fully aquatic goby species do not have the ability... | Mudskipper | Wikipedia | 455 | 4063480 | https://en.wikipedia.org/wiki/Mudskipper | Biology and health sciences | Acanthomorpha | Animals | vital_articles |
Hyneria is a genus of large prehistoric predatory lobe-finned fish which lived in fresh water during the Famennian stage of the Devonian period.
Etymology
The genus name Hyneria is a reference to the village of Hyner, Pennsylvania, near where the first specimen was found. The species epithet H. lindae is derived from ... | Hyneria | Wikipedia | 506 | 4064886 | https://en.wikipedia.org/wiki/Hyneria | Biology and health sciences | Prehistoric osteichthyans | Animals | vital_articles |
In numerical linear algebra, the method of successive over-relaxation (SOR) is a variant of the Gauss–Seidel method for solving a linear system of equations, resulting in faster convergence. A similar method can be used for any slowly converging iterative process.
It was devised simultaneously by David M. Young Jr. an... | Successive over-relaxation | Wikipedia | 504 | 4068447 | https://en.wikipedia.org/wiki/Successive%20over-relaxation | Mathematics | Linear algebra | null | vital_articles |
In particular, for (Gauss-Seidel) it holds that .
For the optimal we get , which shows SOR is roughly four times more efficient than Gauss–Seidel.
The last assumption is satisfied for tridiagonal matrices since for diagonal with entries and .
Algorithm
Since elements can be overwritten as they are computed i... | Successive over-relaxation | Wikipedia | 374 | 4068447 | https://en.wikipedia.org/wiki/Successive%20over-relaxation | Mathematics | Linear algebra | null | vital_articles |
(defun get-errors (computed-solution exact-solution)
"For each component of the COMPUTED-SOLUTION vector, retrieves its
error with respect to the expected EXACT-SOLUTION vector, returning a
vector of error values.
---
While both input vectors should be equal in size, this condition is
not checked and t... | Successive over-relaxation | Wikipedia | 437 | 4068447 | https://en.wikipedia.org/wiki/Successive%20over-relaxation | Mathematics | Linear algebra | null | vital_articles |
(defun successive-over-relaxation (A b omega
&key (phi (make-zero-vector (length b)))
(convergence-check
#'(lambda (iteration phi)
(declare (ignore phi))
... | Successive over-relaxation | Wikipedia | 507 | 4068447 | https://en.wikipedia.org/wiki/Successive%20over-relaxation | Mathematics | Linear algebra | null | vital_articles |
(* (/ omega (aref A i i))
(- (aref b i) rho))))))
(format T "~&~d. solution = ~a" iteration phi)
;; Check if convergence is reached.
(when (funcall convergence-check iteration phi)
(return))))
(the (vector number *) phi)) | Successive over-relaxation | Wikipedia | 82 | 4068447 | https://en.wikipedia.org/wiki/Successive%20over-relaxation | Mathematics | Linear algebra | null | vital_articles |
;; Summon the function with the exemplary parameters.
(let ((A (make-array (list 4 4)
:initial-contents
'(( 4 -1 -6 0 )
( -5 -4 10 8 )
( 0 9 4 -2 )
( 1 0 -7 5 )... | Successive over-relaxation | Wikipedia | 246 | 4068447 | https://en.wikipedia.org/wiki/Successive%20over-relaxation | Mathematics | Linear algebra | null | vital_articles |
def sor_solver(A, b, omega, initial_guess, convergence_criteria):
"""
This is an implementation of the pseudo-code provided in the Wikipedia article.
Arguments:
A: nxn numpy matrix.
b: n dimensional numpy vector.
omega: relaxation factor.
initial_guess: An initial solution gu... | Successive over-relaxation | Wikipedia | 498 | 4068447 | https://en.wikipedia.org/wiki/Successive%20over-relaxation | Mathematics | Linear algebra | null | vital_articles |
However, the formulation presented above, used for solving systems of linear equations, is not a special case of this formulation if is considered to be the complete vector. If this formulation is used instead, the equation for calculating the next vector will look like
where . Values of are used to speed up converg... | Successive over-relaxation | Wikipedia | 139 | 4068447 | https://en.wikipedia.org/wiki/Successive%20over-relaxation | Mathematics | Linear algebra | null | vital_articles |
In geology, basement and crystalline basement are crystalline rocks lying above the mantle and beneath all other rocks and sediments. They are sometimes exposed at the surface, but often they are buried under miles of rock and sediment. The basement rocks lie below a sedimentary platform or cover, or more generally any... | Basement (geology) | Wikipedia | 441 | 5417918 | https://en.wikipedia.org/wiki/Basement%20%28geology%29 | Physical sciences | Stratigraphy | Earth science | vital_articles |
The basement rocks are often highly metamorphosed and complex, and are usually crystalline. They may consist of many different types of rock – volcanic, intrusive igneous and metamorphic. They may also contain ophiolites, which are fragments of oceanic crust that became wedged between plates when a terrane was accreted... | Basement (geology) | Wikipedia | 369 | 5417918 | https://en.wikipedia.org/wiki/Basement%20%28geology%29 | Physical sciences | Stratigraphy | Earth science | vital_articles |
Oceanic crust can be subducted, while continental crust cannot. Eventually, the subduction of the underthrusting oceanic crust can bring the volcanic arc close to a continent, with which it may collide. When this happens, instead of being subducted, it is accreted to the edge of the continent and becomes part of it. Th... | Basement (geology) | Wikipedia | 498 | 5417918 | https://en.wikipedia.org/wiki/Basement%20%28geology%29 | Physical sciences | Stratigraphy | Earth science | vital_articles |
The term basement is used mostly in disciplines of geology like basin geology, sedimentology and petroleum geology in which the (typically Precambrian) crystalline basement is not of interest as it rarely contains petroleum or natural gas. The term economic basement is also used to describe the deeper parts of a cover ... | Basement (geology) | Wikipedia | 67 | 5417918 | https://en.wikipedia.org/wiki/Basement%20%28geology%29 | Physical sciences | Stratigraphy | Earth science | vital_articles |
Hemp, or industrial hemp, is a plant in the botanical class of Cannabis sativa cultivars grown specifically for industrial and consumable use. It can be used to make a wide range of products. Along with bamboo, hemp is among the fastest growing plants on Earth. It was also one of the first plants to be spun into usable... | Hemp | Wikipedia | 468 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Cognates of hemp in other Germanic languages include Dutch , Danish and Norwegian , Saterland Frisian , German , Icelandic and Swedish . In those languages "hemp" can refer to either industrial fiber hemp or narcotic cannabis strains.
Uses
Hemp is used to make a variety of commercial and industrial products, includi... | Hemp | Wikipedia | 467 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
The share of protein obtained from the hemp seeds can be increased in by processing the seeds, such as by dehulling the seeds, or by using the meal or cake (also called hemp seed flour), that is, the remaining fraction of hemp seed obtained after expelling its oil fraction. The proteins are mostly located in the inner ... | Hemp | Wikipedia | 438 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Hemp seeds are a rich source of dietary fiber (20% DV), B vitamins, and the dietary minerals manganese (362% DV), phosphorus (236% DV), magnesium (197% DV), zinc (104% DV), and iron (61% DV). About 73% of the energy in hemp seeds is in the form of fats and essential fatty acids, mainly polyunsaturated fatty acids, lino... | Hemp | Wikipedia | 459 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Building material
Hemp as a building construction material provides solutions to a variety of issues facing current building standards. Its light weight, mold resistance, breathability, etc. makes hemp products versatile in a multitude of uses. Following the co-heating tests of NNFCC Renewable House at the Building Res... | Hemp | Wikipedia | 495 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Sustainability
Hemp is classified under the green category of building design, primarily due to its positive effects on the environment. A few of its benefits include but are not limited to the suppression of weed growth, anti-erosion, reclamation properties, and the ability to remove poisonous substances and heavy me... | Hemp | Wikipedia | 460 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Hemp insulation's porous materiality allows for air and moisture penetration, with a bulk density going up to 20% without losing any thermal properties. In contrast, the commonly used mineral insulation starts to fail after 2%. The insulation evenly distributes vapor and allows for air circulation, constantly carrying ... | Hemp | Wikipedia | 507 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Cannabis seeds have high-fat content and contain 30-35% of fatty acids. The extracted oil is suited for a variety of construction applications. The biodegradable hemp oil acts as a wood varnish, protecting flooring from mold, pests, and wear. Its use prevents the water from penetrating the wood while still allowing air... | Hemp | Wikipedia | 460 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
A mixture of fiberglass, hemp fiber, kenaf, and flax has been used since 2002 to make composite panels for automobiles. The choice of which bast fiber to use is primarily based on cost and availability.
Various car makers are beginning to use hemp in their cars, including Audi, BMW, Ford, GM, Chrysler, Honda, Iveco, Lo... | Hemp | Wikipedia | 123 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Hemp paper are paper varieties consisting exclusively or to a large extent from pulp obtained from fibers of industrial hemp. The products are mainly specialty papers such as cigarette paper, banknotes and technical filter papers. Compared to wood pulp, hemp pulp offers a four to five times longer fiber, a significantl... | Hemp | Wikipedia | 441 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
However, hemp has had a hard time competing with paper from trees or recycled newsprint. Only the outer part of the stem consists mainly of fibers which are suitable for the production of paper. Numerous attempts have been made to develop machines that efficiently and inexpensively separate useful fibers from less usef... | Hemp | Wikipedia | 499 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Hemp crops are tall, have thick foliage, and can be planted densely, and thus can be grown as a smother crop to kill tough weeds. Using hemp this way can help farmers avoid the use of herbicides, gain organic certification, and gain the benefits of crop rotation. However, due to the plant's rapid and dense growth chara... | Hemp | Wikipedia | 482 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Hemp is usually planted between March and May in the northern hemisphere, between September and November in the southern hemisphere. It matures in about three to four months, depending on various conditions.
Millennia of selective breeding have resulted in varieties that display a wide range of traits; e.g. suited for... | Hemp | Wikipedia | 468 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Cannabis sativa L. subsp. sativa var. sativa is the variety grown for industrial use, while C. sativa subsp. indica generally has poor fiber quality and female buds from this variety are primarily used for recreational and medicinal purposes. The major differences between the two types of plants are the appearance, and... | Hemp | Wikipedia | 292 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Pests
Several arthropods can cause damage or injury to hemp plants, but the most serious species are associated with the Insecta class. The most problematic for outdoor crops are the voracious stem-boring caterpillars, which include the European corn borer, Ostrinia nubilalis, and the Eurasian hemp borer, Grapholita d... | Hemp | Wikipedia | 396 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Environmental impact
Hemp is considered by a 1998 study in Environmental Economics to be environmentally friendly due to a decrease of land use and other environmental impacts, indicating a possible decrease of ecological footprint in a US context compared to typical benchmarks. A 2010 study, however, that compared the... | Hemp | Wikipedia | 396 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
Air-dried stem yields in Ontario have from 1998 and onward ranged from 2.6 to 14.0 tons of dry, retted stalks per hectare (1–5.5 t/ac) at 12% moisture. Yields in Kent County, have averaged 8.75 t/ha (3.5 t/ac). Northern Ontario crops averaged 6.1 t/ha (2.5 t/ac) in 1998. Statistic for the European Union for 2008 to 201... | Hemp | Wikipedia | 501 | 963313 | https://en.wikipedia.org/wiki/Hemp | Biology and health sciences | Rosales | Plants | vital_articles |
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