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The aorta is an elastic artery, and as such is quite distensible. The aorta consists of a heterogeneous mixture of smooth muscle, nerves, intimal cells, endothelial cells, immune cells, fibroblast-like cells, and a complex extracellular matrix. The vascular wall is subdivided into three layers known as the tunica exter... | Aorta | Wikipedia | 480 | 2089 | https://en.wikipedia.org/wiki/Aorta | Biology and health sciences | Circulatory system | Biology |
In patent ductus arteriosus, a congenital disorder, the fetal ductus arteriosus fails to close, leaving an open vessel connecting the pulmonary artery to the proximal descending aorta.
Function
The aorta supplies all of the systemic circulation, which means that the entire body, except for the respiratory zone of the... | Aorta | Wikipedia | 390 | 2089 | https://en.wikipedia.org/wiki/Aorta | Biology and health sciences | Circulatory system | Biology |
Mean arterial pressure (MAP) is highest in the aorta, and the MAP decreases across the circulation from aorta to arteries to arterioles to capillaries to veins back to atrium. The difference between aortic and right atrial pressure accounts for blood flow in the circulation. When the left ventricle contracts to force b... | Aorta | Wikipedia | 404 | 2089 | https://en.wikipedia.org/wiki/Aorta | Biology and health sciences | Circulatory system | Biology |
All amniotes have a broadly similar arrangement to that of humans, albeit with a number of individual variations. In fish, however, there are two separate vessels referred to as aortas. The ventral aorta carries de-oxygenated blood from the heart to the gills; part of this vessel forms the ascending aorta in tetrapods ... | Aorta | Wikipedia | 248 | 2089 | https://en.wikipedia.org/wiki/Aorta | Biology and health sciences | Circulatory system | Biology |
In mathematics, the axiom of regularity (also known as the axiom of foundation) is an axiom of Zermelo–Fraenkel set theory that states that every non-empty set A contains an element that is disjoint from A. In first-order logic, the axiom reads:
The axiom of regularity together with the axiom of pairing implies that n... | Axiom of regularity | Wikipedia | 505 | 2113 | https://en.wikipedia.org/wiki/Axiom%20of%20regularity | Mathematics | Axiomatic systems | null |
No infinite descending sequence of sets exists
Suppose, to the contrary, that there is a function, f, on the natural numbers with f(n+1) an element of f(n) for each n. Define S = {f(n): n a natural number}, the range of f, which can be seen to be a set from the axiom schema of replacement. Applying the axiom of regular... | Axiom of regularity | Wikipedia | 438 | 2113 | https://en.wikipedia.org/wiki/Axiom%20of%20regularity | Mathematics | Axiomatic systems | null |
Simpler set-theoretic definition of the ordered pair
The axiom of regularity enables defining the ordered pair (a,b) as {a,{a,b}}; see ordered pair for specifics. This definition eliminates one pair of braces from the canonical Kuratowski definition (a,b) = {{a},{a,b}}.
Every set has an ordinal rank
This was actually... | Axiom of regularity | Wikipedia | 508 | 2113 | https://en.wikipedia.org/wiki/Axiom%20of%20regularity | Mathematics | Axiomatic systems | null |
Regularity and the rest of ZF(C) axioms
Regularity was shown to be relatively consistent with the rest of ZF by Skolem and von Neumann, meaning that if ZF without regularity is consistent, then ZF (with regularity) is also consistent.
The axiom of regularity was also shown to be independent from the other axioms of Z... | Axiom of regularity | Wikipedia | 435 | 2113 | https://en.wikipedia.org/wiki/Axiom%20of%20regularity | Mathematics | Axiomatic systems | null |
If a theory is extended by adding an axiom or axioms, then any (possibly undesirable) consequences of the original theory remain consequences of the extended theory. In particular, if ZF without regularity is extended by adding regularity to get ZF, then any contradiction (such as Russell's paradox) which followed from... | Axiom of regularity | Wikipedia | 489 | 2113 | https://en.wikipedia.org/wiki/Axiom%20of%20regularity | Mathematics | Axiomatic systems | null |
Skolem and von Neumann pointed out that non-well-founded sets are superfluous and in the same publication von Neumann gives an axiom which excludes some, but not all, non-well-founded sets. In a subsequent publication, von Neumann gave an equivalent but more complex version of the axiom of class foundation:
The contem... | Axiom of regularity | Wikipedia | 187 | 2113 | https://en.wikipedia.org/wiki/Axiom%20of%20regularity | Mathematics | Axiomatic systems | null |
Apple II ("apple two") is a series of microcomputers manufactured by Apple Computer, Inc. from 1977 to 1993. The first Apple II model, that gave the series its name, was designed by Steve Wozniak, and was first sold on June 10, 1977. Its success led to it being followed by the Apple II Plus, Apple IIe, Apple IIc, and A... | Apple II | Wikipedia | 504 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
Unlike preceding home microcomputers, the Apple II was sold as a finished consumer appliance rather than as a kit (unassembled or preassembled). Apple marketed the Apple II as a durable product, including a 1981 ad in which an Apple II survived a fire started when a cat belonging to one early user knocked over a lamp.... | Apple II | Wikipedia | 478 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
Much commercial Apple II software shipped on self-booting disks and does not use standard DOS disk formats. This discouraged the copying or modifying of the software on the disks, and improved loading speed.
Models
Apple II
The first Apple II computers went on sale on June 10, 1977 with a MOS Technology 6502 (later ... | Apple II | Wikipedia | 413 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
The Apple II's multiple expansion slots permitted a wide variety of third-party devices, including Apple II peripheral cards such as serial controllers, display controllers, memory boards, hard disks, networking components, and real-time clocks. There were plug-in expansion cards – such as the Z-80 SoftCard – that perm... | Apple II | Wikipedia | 479 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
The Apple II Plus was followed in 1983 by the Apple IIe, a cost-reduced yet more powerful machine that used newer chips to reduce the component count and add new features, such as the display of upper and lowercase letters and a standard 64 KB of RAM.
The IIe RAM was configured as if it were a 48 KB Apple II Plus with... | Apple II | Wikipedia | 504 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
Two different monochrome LC displays were sold for use with the IIc's video expansion port, although both were short-lived due to high cost and poor legibility. The IIc had an external power supply that converted AC power to 15 V DC, though the IIc itself will accept between 12 V and 17 V DC, allowing third parties to ... | Apple II | Wikipedia | 437 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
The final Apple II model was the Apple IIc Plus introduced in 1988. It was the same size and shape as the IIc that came before it, but the 5.25-inch floppy drive had been replaced with a -inch drive, the power supply was moved inside the case, and the processor was a fast 4 MHz 65C02 processor that actually ran 8-bit A... | Apple II | Wikipedia | 382 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
With a breakout cable which connected to the back of the card, the user could attach up to two UniDisk or Apple 5.25 Drives, up to one UniDisk 3.5 drive, and a DE-9 Apple II joystick. Many of the LC's built-in Macintosh peripherals could also be "borrowed" by the card when in Apple II mode, including extra RAM, the Ma... | Apple II | Wikipedia | 446 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
Apple ran the first advertisement for the Apple II, a two-page spread ad titled "Introducing Apple II", in BYTE in July 1977. The first brochure, was entitled "Simplicity" and the copy in both the ad and brochure pioneered "demystifying" language intended to make the new idea of a home computer more "personal." The App... | Apple II | Wikipedia | 442 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
Even after disk drives made the cassette tape interfaces obsolete they were still used by enthusiasts as simple one-bit audio input-output ports. Ham radio operators used the cassette input to receive slow scan TV (single frame images). A commercial speech recognition Blackjack program was available, after some user-sp... | Apple II | Wikipedia | 475 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
Later, double-sided drives, with heads to read both sides of the disk, became available from third-party companies. (Apple only produced double-sided 5.25-inch disks for the Lisa 1 computer).
On a DOS 3.x disk, tracks 0, 1, and most of track 2 were reserved to store the operating system. (It was possible, with a speci... | Apple II | Wikipedia | 412 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
The Apple Disk II stored 140 KB on single-sided, "single-density" floppy disks, but it was very common for Apple II users to extend the capacity of a single-sided floppy disk to 280 KB by cutting out a second write-protect notch on the side of the disk using a "disk notcher" or hole puncher and inserting the disk flipp... | Apple II | Wikipedia | 471 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
The Apple II's popularity bootstrapped the computer game and educational software markets and began the boom in the word processor and computer printer markets. The first spreadsheet application, VisiCalc, was initially released for the Apple II, and many businesses bought them just to run VisiCalc. Its success drove I... | Apple II | Wikipedia | 481 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
In 2017, the band 8 Bit Weapon released the world's first 100% Apple II-based music album entitled, "Class Apples". The album featured dance-oriented cover versions of classical music by Bach, Beethoven, and Mozart recorded directly off the Apple II motherboard. | Apple II | Wikipedia | 56 | 2116 | https://en.wikipedia.org/wiki/Apple%20II | Technology | Early computers | null |
In organic chemistry, hydrocarbons (compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. aleiphar, fat, oil). Aliphatic compounds can be saturated (in which all the C-C bonds are single requiring the structure to be completed, or 'saturated', b... | Aliphatic compound | Wikipedia | 457 | 2120 | https://en.wikipedia.org/wiki/Aliphatic%20compound | Physical sciences | Aliphatic hydrocarbons | Chemistry |
Armour (Commonwealth English) or armor (American English; see spelling differences) is a covering used to protect an object, individual, or vehicle from physical injury or damage, especially direct contact weapons or projectiles during combat, or from a potentially dangerous environment or activity (e.g. cycling, const... | Armour | Wikipedia | 437 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
Well-known armour types in European history include the lorica hamata, lorica squamata, and the lorica segmentata of the Roman legions, the mail hauberk of the early medieval age, and the full steel plate harness worn by later medieval and renaissance knights, and breast and back plates worn by heavy cavalry in several... | Armour | Wikipedia | 481 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
Mail, sometimes called "chainmail", made of interlocking iron rings is believed to have first appeared some time after 300 BC. Its invention is credited to the Celts; the Romans are thought to have adopted their design.
Gradually, small additional plates or discs of iron were added to the mail to protect vulnerable ar... | Armour | Wikipedia | 447 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
In the early years of low velocity firearms, full suits of armour, or breast plates actually stopped bullets fired from a modest distance. Crossbow bolts, if still in use, would seldom penetrate good plate, nor would any bullet unless fired from close range. In effect, rather than making plate armour obsolete, the use ... | Armour | Wikipedia | 440 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
At the start of World War I, thousands of the French Cuirassiers rode out to engage the German Cavalry. By that period, the shiny metallic cuirass was covered in a dark paint and a canvas wrap covered their elaborate Napoleonic style helmets, to help mitigate the sunlight being reflected off the surfaces, thereby alert... | Armour | Wikipedia | 477 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
In modern ground forces' usage, the meaning of armour has expanded to include the role of troops in combat. After the evolution of armoured warfare, mechanised infantry were mounted in armoured fighting vehicles and replaced light infantry in many situations. In modern armoured warfare, armoured units equipped with tan... | Armour | Wikipedia | 420 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
Armoured trains saw use from the mid-19th to the mid-20th century, including the American Civil War (1861–1865), the Franco-Prussian War (1870–1871), the First and Second Boer Wars (1880–81 and 1899–1902), the Polish–Soviet War (1919–1921), the First (1914–1918) and Second World Wars (1939–1945) and the First Indochina... | Armour | Wikipedia | 471 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
The armoured personnel carrier (APC) was devised during the First World War. It allows the safe and rapid movement of infantry in a combat zone, minimising casualties and maximising mobility. APCs are fundamentally different from the previously used armoured half-tracks in that they offer a higher level of protection f... | Armour | Wikipedia | 433 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
Body armour for war horses has been used since at least 2000 BC. Cloth, leather, and metal protection covered cavalry horses in ancient civilisations, including ancient Egypt, Assyria, Persia, and Rome. Some formed heavy cavalry units of armoured horses and riders used to attack infantry and mounted archers. Armour for... | Armour | Wikipedia | 400 | 2147 | https://en.wikipedia.org/wiki/Armour | Technology | Weapons | null |
Armadillos () are New World placental mammals in the order Cingulata. They form part of the superorder Xenarthra, along with the anteaters and sloths. 21 extant species of armadillo have been described, some of which are distinguished by the number of bands on their armor. All species are native to the Americas, where ... | Armadillo | Wikipedia | 431 | 2186 | https://en.wikipedia.org/wiki/Armadillo | Biology and health sciences | Mammals | null |
(from ) in Argentina, Bolivia, Chile, Colombia and Peru;
(from Nahuatl) in Costa Rica, El Salvador, Honduras and Nicaragua;
in Argentina and Uruguay;
in Argentina, Chile, Colombia and Uruguay;
in Argentina, Brazil, Chile, Colombia and Paraguay;
in Colombia and Venezuela
in Tolima, Caldas and Antioquia, Colo... | Armadillo | Wikipedia | 240 | 2186 | https://en.wikipedia.org/wiki/Armadillo | Biology and health sciences | Mammals | null |
Family Chlamyphoridae
Subfamily Chlamyphorinae
Genus Calyptophractus
Greater fairy armadillo, Calyptophractus retusus
Genus Chlamyphorus
Pink fairy armadillo, Chlamyphorus truncatus
Subfamily Euphractinae
Genus Chaetophractus
Screaming hairy armadillo, Chaetophractus vellerosus
Big hairy armadillo, Chaetophractu... | Armadillo | Wikipedia | 404 | 2186 | https://en.wikipedia.org/wiki/Armadillo | Biology and health sciences | Mammals | null |
Distribution
Like all of the Xenarthra lineages, armadillos originated in South America. Due to the continent's former isolation, they were confined there for most of the Cenozoic. The recent formation of the Isthmus of Panama allowed a few members of the family to migrate northward into southern North America by the e... | Armadillo | Wikipedia | 442 | 2186 | https://en.wikipedia.org/wiki/Armadillo | Biology and health sciences | Mammals | null |
Armadillos have very poor eyesight, and use their keen sense of smell to hunt for food. They use their claws not only for digging and finding food but also for digging burrows for their dwellings, each of which is a single corridor the width of the animal's body. They have five clawed toes on their hind feet, and three... | Armadillo | Wikipedia | 471 | 2186 | https://en.wikipedia.org/wiki/Armadillo | Biology and health sciences | Mammals | null |
Movement
Armadillos have short legs, but can move quite quickly. The nine-banded armadillo is noted for its movement through water, which is accomplished via two different methods: it can walk underwater for short distances, holding its breath for as long as six minutes; or, to cross larger bodies of water, it can inc... | Armadillo | Wikipedia | 447 | 2186 | https://en.wikipedia.org/wiki/Armadillo | Biology and health sciences | Mammals | null |
The nine-banded armadillo also serves science through its unusual reproductive system, in which four genetically identical offspring are born, the result of one original egg. Because they are always genetically identical, the group of four young provides a good subject for scientific, behavioral, or medical tests that ... | Armadillo | Wikipedia | 428 | 2186 | https://en.wikipedia.org/wiki/Armadillo | Biology and health sciences | Mammals | null |
In mathematics, analytic geometry, also known as coordinate geometry or Cartesian geometry, is the study of geometry using a coordinate system. This contrasts with synthetic geometry.
Analytic geometry is used in physics and engineering, and also in aviation, rocketry, space science, and spaceflight. It is the foundat... | Analytic geometry | Wikipedia | 498 | 2202 | https://en.wikipedia.org/wiki/Analytic%20geometry | Mathematics | Geometry | null |
Persia
The 11th-century Persian mathematician Omar Khayyam saw a strong relationship between geometry and algebra and was moving in the right direction when he helped close the gap between numerical and geometric algebra with his geometric solution of the general cubic equations, but the decisive step came later with D... | Analytic geometry | Wikipedia | 340 | 2202 | https://en.wikipedia.org/wiki/Analytic%20geometry | Mathematics | Geometry | null |
Pierre de Fermat also pioneered the development of analytic geometry. Although not published in his lifetime, a manuscript form of Ad locos planos et solidos isagoge (Introduction to Plane and Solid Loci) was circulating in Paris in 1637, just prior to the publication of Descartes' Discourse. Clearly written and well r... | Analytic geometry | Wikipedia | 474 | 2202 | https://en.wikipedia.org/wiki/Analytic%20geometry | Mathematics | Geometry | null |
In cylindrical coordinates, every point of space is represented by its height z, its radius r from the z-axis and the angle θ its projection on the xy-plane makes with respect to the horizontal axis.
Spherical coordinates (in a space)
In spherical coordinates, every point in space is represented by its distance ρ fro... | Analytic geometry | Wikipedia | 489 | 2202 | https://en.wikipedia.org/wiki/Analytic%20geometry | Mathematics | Geometry | null |
Specifically, let be the position vector of some point , and let be a nonzero vector. The plane determined by this point and vector consists of those points , with position vector , such that the vector drawn from to is perpendicular to . Recalling that two vectors are perpendicular if and only if their dot product... | Analytic geometry | Wikipedia | 509 | 2202 | https://en.wikipedia.org/wiki/Analytic%20geometry | Mathematics | Geometry | null |
In analytic geometry, geometric notions such as distance and angle measure are defined using formulas. These definitions are designed to be consistent with the underlying Euclidean geometry. For example, using Cartesian coordinates on the plane, the distance between two points (x1, y1) and (x2, y2) is defined by the ... | Analytic geometry | Wikipedia | 494 | 2202 | https://en.wikipedia.org/wiki/Analytic%20geometry | Mathematics | Geometry | null |
Transformations can be applied to any geometric equation whether or not the equation represents a function.
Transformations can be considered as individual transactions or in combinations.
Suppose that is a relation in the plane. For example,
is the relation that describes the unit circle.
Finding intersections o... | Analytic geometry | Wikipedia | 497 | 2202 | https://en.wikipedia.org/wiki/Analytic%20geometry | Mathematics | Geometry | null |
Also for this may be used the common language use as a: normal (perpendicular) line, otherwise in engineering as axial line.
In geometry, a normal is an object such as a line or vector that is perpendicular to a given object. For example, in the two-dimensional case, the normal line to a curve at a given point is the ... | Analytic geometry | Wikipedia | 406 | 2202 | https://en.wikipedia.org/wiki/Analytic%20geometry | Mathematics | Geometry | null |
The Arctic fox (Vulpes lagopus), also known as the white fox, polar fox, or snow fox, is a small species of fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome. It is well adapted to living in cold environments, and is best known for its thick, warm fur that is also... | Arctic fox | Wikipedia | 484 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
Arctic foxes tend to select dens that are easily accessible with many entrances, and that are clear from snow and ice making it easier to burrow in. The Arctic fox builds and chooses dens that face southward towards the sun, which makes the den warmer. Arctic foxes prefer large, maze-like dens for predator evasion and ... | Arctic fox | Wikipedia | 340 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
Arctic foxes are primarily monogamous and both parents will care for the offspring. When predators and prey are abundant, Arctic foxes are more likely to be promiscuous (exhibited in both males and females) and display more complex social structures. Larger packs of foxes consisting of breeding or non-breeding males or... | Arctic fox | Wikipedia | 424 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
Arctic foxes survive harsh winters and food scarcity by either hoarding food or storing body fat subcutaneously and viscerally. At the beginning of winter, one Arctic fox has approximately 14740 kJ of energy storage from fat alone. Using the lowest BMR value measured in Arctic foxes, an average sized fox of would need... | Arctic fox | Wikipedia | 428 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
Sensory modalities
The Arctic fox has a functional hearing range between 125 Hz–16 kHz with a sensitivity that is ≤ 60 dB in air, and an average peak sensitivity of 24 dB at 4 kHz. Overall, the Arctic foxes hearing is less sensitive than the dog and the kit fox. The Arctic fox and the kit fox have a low upper-frequency... | Arctic fox | Wikipedia | 406 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
About 22% of the total body surface area of the Arctic fox dissipates heat readily compared to red foxes at 33%. The regions that have the greatest heat loss are the nose, ears, legs, and feet, which is useful in the summer for thermal heat regulation. Also, the Arctic fox has a beneficial mechanism in their nose for e... | Arctic fox | Wikipedia | 481 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
It was originally described by Carl Linnaeus in the 10th edition of Systema Naturae in 1758 as Canis lagopus. The type specimen was recovered from Lapland, Sweden. The generic name vulpes is Latin for "fox". The specific name lagopus is derived from Ancient Greek λαγώς (lagōs, "hare") and πούς (pous, "foot"), referring... | Arctic fox | Wikipedia | 456 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
The Arctic fox has a circumpolar distribution and occurs in Arctic tundra habitats in northern Europe, northern Asia, and North America. Its range includes Greenland, Iceland, Fennoscandia, Svalbard, Jan Mayen (where it was hunted to extinction) and other islands in the Barents Sea, northern Russia, islands in the Beri... | Arctic fox | Wikipedia | 491 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
Arctic foxes closer to goose colonies (located at the coasts) are less likely to migrate. Meanwhile, foxes experiencing low-density lemming populations are more likely to make sea ice trips. Residency is common in the Arctic fox population so that they can maintain their territories. Migratory foxes have a mortality ra... | Arctic fox | Wikipedia | 469 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
The Arctic fox is losing ground to the larger red fox. This has been attributed to climate change—the camouflage value of its lighter coat decreases with less snow cover. Red foxes dominate where their ranges begin to overlap by killing Arctic foxes and their kits. An alternative explanation of the red fox's gains invo... | Arctic fox | Wikipedia | 487 | 2208 | https://en.wikipedia.org/wiki/Arctic%20fox | Biology and health sciences | Canines | Animals |
The Apicomplexa (also called Apicomplexia; single: apicomplexan) are organisms of a large phylum of mainly parasitic alveolates. Most possess a unique form of organelle structure that comprises a type of non-photosynthetic plastid called an apicoplastwith an apical complex membrane. The organelle's apical shape (e.g., ... | Apicomplexa | Wikipedia | 511 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
The phylum Apicomplexa contains all eukaryotes with a group of structures and organelles collectively termed the apical complex. This complex consists of structural components and secretory organelles required for invasion of host cells during the parasitic stages of the Apicomplexan life cycle. Apicomplexa have comple... | Apicomplexa | Wikipedia | 263 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
All members of this phylum have an infectious stage—the sporozoite—which possesses three distinct structures in an apical complex. The apical complex consists of a set of spirally arranged microtubules (the conoid), a secretory body (the rhoptry) and one or more polar rings. Additional slender electron-dense secretory ... | Apicomplexa | Wikipedia | 479 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
Most members have a complex lifecycle, involving both asexual and sexual reproduction. Typically, a host is infected via an active invasion by the parasites (similar to entosis), which divide to produce sporozoites that enter its cells. Eventually, the cells burst, releasing merozoites, which infect new cells. This ... | Apicomplexa | Wikipedia | 510 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
The gregarines are generally parasites of annelids, arthropods, and molluscs. They are often found in the guts of their hosts, but may invade the other tissues. In the typical gregarine lifecycle, a trophozoite develops within a host cell into a schizont. This then divides into a number of merozoites by schizogony. The... | Apicomplexa | Wikipedia | 392 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
The main difference between the coccidians and the gregarines is in the gamonts. In the coccidia, these are small, intracellular, and without epimerites or mucrons. In the gregarines, these are large, extracellular, and possess epimerites or mucrons. A second difference between the coccidia and the gregarines also lies... | Apicomplexa | Wikipedia | 337 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
Marosporida
The class Marosporida Mathur, Kristmundsson, Gestal, Freeman, and Keeling 2020 is a newly recognized lineage of apicomplexans that is sister to the Coccidia and Hematozoa. It is defined as a phylogenetic clade containing Aggregata octopiana Frenzel 1885, Merocystis kathae Dakin, 1911 (both Aggregatidae, ori... | Apicomplexa | Wikipedia | 255 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
Many of the apicomplexan parasites are important pathogens of humans and domestic animals. In contrast to bacterial pathogens, these apicomplexan parasites are eukaryotic and share many metabolic pathways with their animal hosts. This makes therapeutic target development extremely difficult – a drug that harms an apico... | Apicomplexa | Wikipedia | 446 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
Similar strategies to increase the likelihood of transmission have evolved in multiple genera. Polyenergid oocysts and tissue cysts are found in representatives of the orders Protococcidiorida and Eimeriida. Hypnozoites are found in Karyolysus lacerate and most species of Plasmodium; transovarial transmission of parasi... | Apicomplexa | Wikipedia | 419 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
History
The first Apicomplexa protozoan was seen by Antonie van Leeuwenhoek, who in 1674 saw probably oocysts of Eimeria stiedae in the gall bladder of a rabbit. The first species of the phylum to be described, Gregarina ovata, in earwigs' intestines, was named by Dufour in 1828. He thought that they were a peculiar gr... | Apicomplexa | Wikipedia | 452 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
Sporozoa is no longer regarded as biologically valid and its use is discouraged, although some authors still use it as a synonym for the Apicomplexa. More recently, other groups were excluded from Apicomplexa, e.g., Perkinsus and Colpodella (now in Protalveolata).
The field of classifying Apicomplexa is in flux and cl... | Apicomplexa | Wikipedia | 448 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
Roberts and Janovy (1996)
Roberts and Janovy in 1996 divided the phylum into the following subclasses and suborders (omitting classes and orders):
Subclass Gregarinasina (the gregarines)
Subclass Coccidiasina
Suborder Adeleorina (the adeleorins)
Suborder Eimeriorina (the eimeriorins)
Suborder Haemospororina (the h... | Apicomplexa | Wikipedia | 328 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
Perkins et al. proposed the following scheme. It is outdated as the Perkinsidae have since been recognised as a sister group to the dinoflagellates rather that the Apicomplexia:
Class Aconoidasida
Conoid present only in the ookinete of some species
Order Haemospororida
Macrogamete and microgamete develop separately... | Apicomplexa | Wikipedia | 451 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
These phylogenetic relations have rarely been studied at the subclass level. The Haemosporidia are related to the gregarines, and the piroplasms and coccidians are sister groups. The Haemosporidia and the Piroplasma appear to be sister clades, and are more closely related to the coccidians than to the gregarines. Maros... | Apicomplexa | Wikipedia | 154 | 2221 | https://en.wikipedia.org/wiki/Apicomplexa | Biology and health sciences | SAR supergroup | Plants |
In computer science, the analysis of algorithms is the process of finding the computational complexity of algorithms—the amount of time, storage, or other resources needed to execute them. Usually, this involves determining a function that relates the size of an algorithm's input to the number of steps it takes (its ti... | Analysis of algorithms | Wikipedia | 498 | 2230 | https://en.wikipedia.org/wiki/Analysis%20of%20algorithms | Mathematics | Algorithms | null |
Cost models
Time efficiency estimates depend on what we define to be a step. For the analysis to correspond usefully to the actual run-time, the time required to perform a step must be guaranteed to be bounded above by a constant. One must be careful here; for instance, some analyses count an addition of two numbers a... | Analysis of algorithms | Wikipedia | 476 | 2230 | https://en.wikipedia.org/wiki/Analysis%20of%20algorithms | Mathematics | Algorithms | null |
Take as an example a program that looks up a specific entry in a sorted list of size n. Suppose this program were implemented on Computer A, a state-of-the-art machine, using a linear search algorithm, and on Computer B, a much slower machine, using a binary search algorithm. Benchmark testing on the two computers ru... | Analysis of algorithms | Wikipedia | 460 | 2230 | https://en.wikipedia.org/wiki/Analysis%20of%20algorithms | Mathematics | Algorithms | null |
Empirical orders of growth
Assuming the run-time follows power rule, , the coefficient can be found by taking empirical measurements of run-time } at some problem-size points }, and calculating so that . In other words, this measures the slope of the empirical line on the log–log plot of run-time vs. input size, at ... | Analysis of algorithms | Wikipedia | 426 | 2230 | https://en.wikipedia.org/wiki/Analysis%20of%20algorithms | Mathematics | Algorithms | null |
The loops in steps 4, 5 and 6 are trickier to evaluate. The outer loop test in step 4 will execute ( n + 1 )
times, which will consume T4( n + 1 ) time. The inner loop, on the other hand, is governed by the value of j, which iterates from 1 to i. On the first pass through the outer loop, j iterates from 1 to 1: The... | Analysis of algorithms | Wikipedia | 472 | 2230 | https://en.wikipedia.org/wiki/Analysis%20of%20algorithms | Mathematics | Algorithms | null |
In this instance, as the file size n increases, memory will be consumed at an exponential growth rate, which is order . This is an extremely rapid and most likely unmanageable growth rate for consumption of memory resources.
Relevance
Algorithm analysis is important in practice because the accidental or unintentional ... | Analysis of algorithms | Wikipedia | 498 | 2230 | https://en.wikipedia.org/wiki/Analysis%20of%20algorithms | Mathematics | Algorithms | null |
An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in some instances eliminate, sensation, although analgesia and anesthesia are neu... | Analgesic | Wikipedia | 486 | 2246 | https://en.wikipedia.org/wiki/Analgesic | Biology and health sciences | Drugs and pharmacology | null |
These drugs have been derived from NSAIDs. The cyclooxygenase enzyme inhibited by NSAIDs was discovered to have at least two different versions: COX1 and COX2. Research suggested most of the adverse effects of NSAIDs to be mediated by blocking the COX1 (constitutive) enzyme, with the analgesic effects being mediated by... | Analgesic | Wikipedia | 248 | 2246 | https://en.wikipedia.org/wiki/Analgesic | Biology and health sciences | Drugs and pharmacology | null |
Morphine, the archetypal opioid, and other opioids (e.g., codeine, oxycodone, hydrocodone, dihydromorphine, pethidine) all exert a similar influence on the cerebral opioid receptor system. Buprenorphine is a partial agonist of the μ-opioid receptor, and tramadol is a serotonin norepinephrine reuptake inhibitor (SNRI) w... | Analgesic | Wikipedia | 459 | 2246 | https://en.wikipedia.org/wiki/Analgesic | Biology and health sciences | Drugs and pharmacology | null |
When used appropriately, opioids and other central analgesics are safe and effective; however, risks such as addiction and the body's becoming used to the drug (tolerance) can occur. The effect of tolerance means that frequent use of the drug may result in its diminished effect. When safe to do so, the dosage may need ... | Analgesic | Wikipedia | 509 | 2246 | https://en.wikipedia.org/wiki/Analgesic | Biology and health sciences | Drugs and pharmacology | null |
While the use of paracetamol, aspirin, ibuprofen, naproxen, and other NSAIDS concurrently with weak to mid-range opiates (up to about the hydrocodone level) has been said to show beneficial synergistic effects by combating pain at multiple sites of action, several combination analgesic products have been shown to have ... | Analgesic | Wikipedia | 477 | 2246 | https://en.wikipedia.org/wiki/Analgesic | Biology and health sciences | Drugs and pharmacology | null |
Adjuvant analgesics, also called atypical analgesics, include orphenadrine, mexiletine, pregabalin, gabapentin, cyclobenzaprine, hyoscine (scopolamine), and other drugs possessing anticonvulsant, anticholinergic, and/or antispasmodic properties, as well as many other drugs with CNS actions. These drugs are used along w... | Analgesic | Wikipedia | 329 | 2246 | https://en.wikipedia.org/wiki/Analgesic | Biology and health sciences | Drugs and pharmacology | null |
Topical analgesia is generally recommended to avoid systemic side-effects. Painful joints, for example, may be treated with an ibuprofen- or diclofenac-containing gel (The labeling for topical diclofenac has been updated to warn about drug-induced hepatotoxicity.); capsaicin also is used topically. Lidocaine, an anesth... | Analgesic | Wikipedia | 301 | 2246 | https://en.wikipedia.org/wiki/Analgesic | Biology and health sciences | Drugs and pharmacology | null |
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which produces steroid hormones and an inner medulla. The adrenal cortex itself is... | Adrenal gland | Wikipedia | 499 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
The adrenal glands are surrounded by a fatty capsule and lie within the renal fascia, which also surrounds the kidneys. A weak septum (wall) of connective tissue separates the glands from the kidneys. The adrenal glands are directly below the diaphragm, and are attached to the crura of the diaphragm by the renal fascia... | Adrenal gland | Wikipedia | 490 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Zona reticularis
The innermost cortical layer, the zona reticularis, lies directly adjacent to the medulla. It produces androgens, mainly dehydroepiandrosterone (DHEA), DHEA sulfate (DHEA-S), and androstenedione (the precursor to testosterone) in humans. Its small cells form irregular cords and clusters, separated by c... | Adrenal gland | Wikipedia | 497 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
The central adrenomedullary vein, in the adrenal medulla, is an unusual type of blood vessel. Its structure is different from the other veins in that the smooth muscle in its tunica media (the middle layer of the vessel) is arranged in conspicuous, longitudinally oriented bundles.
Variability
The adrenal glands may no... | Adrenal gland | Wikipedia | 462 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Glucocorticoids
Cortisol is the main glucocorticoid in humans. In species that do not create cortisol, this role is played by corticosterone instead. Glucocorticoids have many effects on metabolism. As their name suggests, they increase the circulating level of glucose. This is the result of an increase in the mobiliza... | Adrenal gland | Wikipedia | 500 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
The initial part of conversion of cholesterol into steroid hormones involves a number of enzymes of the cytochrome P450 family that are located in the inner membrane of mitochondria. Transport of cholesterol from the outer to the inner membrane is facilitated by steroidogenic acute regulatory protein and is the rate-li... | Adrenal gland | Wikipedia | 495 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Mineralocorticoid secretion is regulated mainly by the renin–angiotensin–aldosterone system (RAAS), the concentration of potassium, and to a lesser extent the concentration of ACTH. Sensors of blood pressure in the juxtaglomerular apparatus of the kidneys release the enzyme renin into the blood, which starts a cascade ... | Adrenal gland | Wikipedia | 406 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Formation
Catecholamines are produced in chromaffin cells in the medulla of the adrenal gland, from tyrosine, a non-essential amino acid derived from food or produced from phenylalanine in the liver. The enzyme tyrosine hydroxylase converts tyrosine to L-DOPA in the first step of catecholamine synthesis. L-DOPA is then... | Adrenal gland | Wikipedia | 405 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Development
The adrenal glands are composed of two heterogenous types of tissue. In the center is the adrenal medulla, which produces adrenaline and noradrenaline and releases them into the bloodstream, as part of the sympathetic nervous system. Surrounding the medulla is the cortex, which produces a variety of steroid... | Adrenal gland | Wikipedia | 238 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Cortex
Adrenal cortex tissue is derived from the intermediate mesoderm. It first appears 33 days after fertilisation, shows steroid hormone production capabilities by the eighth week and undergoes rapid growth during the first trimester of pregnancy. The fetal adrenal cortex is different from its adult counterpart, as ... | Adrenal gland | Wikipedia | 448 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Medulla
The adrenal medulla is derived from neural crest cells, which come from the ectoderm layer of the embryo. These cells migrate from their initial position and aggregate in the vicinity of the dorsal aorta, a primitive blood vessel, which activates the differentiation of these cells through the release of protein... | Adrenal gland | Wikipedia | 480 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Primary aldosteronism
When the zona glomerulosa produces excess aldosterone, the result is primary aldosteronism. Causes for this condition are bilateral hyperplasia (excessive tissue growth) of the glands, or aldosterone-producing adenomas (a condition called Conn's syndrome). Primary aldosteronism produces hypertensi... | Adrenal gland | Wikipedia | 414 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Secondary adrenal insufficiency
In secondary adrenal insufficiency, a dysfunction of the hypothalamic–pituitary–adrenal axis leads to decreased stimulation of the adrenal cortex. Apart from suppression of the axis by glucocorticoid therapy, the most common cause of secondary adrenal insufficiency are tumors that affect... | Adrenal gland | Wikipedia | 430 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
Pheochromocytomas are tumors of the adrenal medulla that arise from chromaffin cells. They can produce a variety of nonspecific symptoms, which include headaches, sweating, anxiety and palpitations. Common signs include hypertension and tachycardia. Surgery, especially adrenal laparoscopy, is the most common treatment ... | Adrenal gland | Wikipedia | 483 | 2296 | https://en.wikipedia.org/wiki/Adrenal%20gland | Biology and health sciences | Animal: General | null |
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