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aphidlion (insect larva)
...device. The female green lacewing secretes slender stalks and deposits one egg on top of each stalk. This prevents the predatory larvae from devouring unhatched eggs. The larva, often called an aphidlion, has prominent sucking mouthparts and well-developed legs. These capture and drain body fluids from aphids and other soft-bodied insects. After about two weeks of continuous feeding, the......
aphin (biochemistry)
The polycyclic quinones occur in some bacteria, fungi, and parts of higher plants. One of the more interesting representatives is the aphin group, so called because of their initial recovery from the hemolymph (circulating fluid) of several coloured species of aphids; aphids parasitize plants, as do the other quinone-assimilating insects....
Aphis forbesi (insect)
...ground, locate a new host plant, and immediately seek roots. The woolly aphid can live indefinitely on the roots of apple trees but can exist only part of the year on elm, the alternate host. The strawberry root louse has a sexual cycle in which eggs are laid, but these aphids are dependent upon ants for survival. The ants not only care for the eggs in their nests but they also carry the......
Aphis gossypii (insect)
The melon, or cotton, aphid (Aphis gossypii) is green to black. In warm climates live young are produced all year, while in cooler areas there is an egg stage. Among the dozens of possible hosts are melon, cotton, and cucumber. It is usually controlled by naturally occurring parasites and predators....
Aphis pomi (insect)
The apple aphid (Aphis pomi) is yellow-green with dark head and legs. It overwinters as a black egg on its only host, the apple tree. It produces honeydew that supports growth of a sooty mold....
Aphobus (guardian of Demosthenes)
Despite this self-improvement program, his first youthful speaking efforts in the public Assembly met with disaster; he was laughed at by his audiences. His lawsuits against Aphobus and two other guardians in 363 were more successful; they produced little money, but he learned much about speaking strategy and methods of argument. Three of his speeches against Aphobus and two against the......
aphonia (pathology)
...The oral cavity is reconnected directly to the esophagus. Having lost his pulmonary activator (air from the lungs) and laryngeal sound generator, such an alaryngeal patient is without a voice (aphonic) and becomes effectively speechless; the faint smacking noises made by the remaining oral structures for articulation are practically unintelligible. This type of pseudo-whispering through......
Aphonopelma (spider genus)
In the southwestern United States, species of the genus Aphonopelma can attain a body length up to 5 cm (almost 2 inches) and a leg span up to 12.5 cm (almost 5 inches). The spiders, dark in colour and sluggish in movement, have a hairy body and hairy legs. The most common member of that genus is A. californicum (Eurypelma californicum; sometimes......
Aphonopelma californicum (spider)
...2 inches) and a leg span up to 12.5 cm (almost 5 inches). The spiders, dark in colour and sluggish in movement, have a hairy body and hairy legs. The most common member of that genus is A. californicum (Eurypelma californicum; sometimes E. californica), which is found in California, Texas, and Arizona. A 30-year life span has been recorded for one...
aphorism (statement)
a concise expression of doctrine or principle or any generally accepted truth conveyed in a pithy, memorable statement. Aphorisms have been especially used in dealing with subjects that were late in developing their own principles or methodology—for example, art, agriculture, medicine, jurisprudence, and politics....
Aphorismi (work attributed to Hippocrates)
The term was first used in the Aphorisms of Hippocrates, a long series of propositions concerning the symptoms and diagnosis of disease and the art of healing and medicine. The first aphorism, which serves as a kind of introduction to the book, runs as follows:Life is short, Art long, Occasion sudden and dangerous, Experience deceitful, and Judgment difficult. Neither is it......
“Aphorisms” (work attributed to Hippocrates)
The term was first used in the Aphorisms of Hippocrates, a long series of propositions concerning the symptoms and diagnosis of disease and the art of healing and medicine. The first aphorism, which serves as a kind of introduction to the book, runs as follows:Life is short, Art long, Occasion sudden and dangerous, Experience deceitful, and Judgment difficult. Neither is it......
aphotic zone (oceanography)
...this zone the production of biochemical energy through photosynthesis is greater than its consumption through respiration and decomposition. Animals and decomposers are found in both the photic and aphotic zones. In the aphotic zone, also called the tropholytic zone, the consumption of energy exceeds its production. The zones are demarcated by a plane of compensation at which primary production...
Aphraates (Syrian ascetic)
Syrian ascetic and the earliest-known Christian writer of the Syriac church in Persia....
Aphredoderus sayanus (fish)
(Aphredoderus sayanus), freshwater fish that is the sole member of the family Aphredoderidae. The pirate perch is found in weedy or muddy creeks, rivers, and lakes of eastern North America. Noteworthy is the peculiar position of its anus, which...
Aphrem Syrus, Saint (Christian theologian)
Christian theologian, poet, hymnist, and doctor of the church who, as doctrinal consultant to Eastern churchmen, composed numerous theological-biblical commentaries and polemical works that, in witnessing to the common Christian tradition, have exerted widespread influence on the Greek and Latin churches. He is recognized as the most authoritative representative of 4th-century Syriac Christianity....
Aphriza virgata (bird)
(Aphriza virgata), American shorebird that has a black triangle on its otherwise white tail. Surfbirds are about 25 centimetres (10 inches) long. With the knots, they constitute the subfamily Calidritinae (family Scolopacidae)....
aphrodisiac (sexual stimulant)
any of various forms of stimulation thought to arouse sexual excitement. Aphrodisiacs may be classified in two principal groups: (1) psychophysiological (visual, tactile, olfactory, aural) and (2) internal (stemming from food, alcoholic drinks, drugs, love potions, medical preparations)....
aphrodisiac pheromone (biochemistry)
The males of some insects produce aphrodisiac pheromones that induce females to mate once the two sexes have come together. One of the most remarkable and fully understood examples of this concerns monarch butterflies (although not the well-known North American monarch). Males of these insects seek out plants containing a particular type of alkaloid known as a pyrrolizidine, which is highly......
Aphrodisias (ancient city, Turkey)
ancient city of the Caria region of southwestern Asia Minor (Anatolia, or modern Turkey), situated on a plateau south of the Maeander River (modern Büyük Menderes). Remains of an Ionic temple of Aphrodite and of a stadiu...
Aphrodita (worm)
(Aphrodita), any of a genus of marine worms of the class Polychaeta (phylum Annelida), named for their mouselike appearance and behaviour....
Aphrodita aculeata (worm)
(Aphrodita), any of a genus of marine worms of the class Polychaeta (phylum Annelida), named for their mouselike appearance and behaviour....
Aphrodite (Greek mythology)
ancient Greek goddess of sexual love and beauty, identified with Venus by the Romans. The Greek word aphros means “foam,” and Hesiod relates in his Theogony that Aphrodite was born from the white foam produced by the severed genitals of Uranus (Heaven), after his son Cronus threw them into the sea. Aphrodite was, i...
Aphrodite Genetrix (work by Callimachus)
...other details in his sculptures. Viewed in this light, the elaborate carving that characterizes the Corinthian capital may well be his invention. Modern scholars have attributed to Callimachus the “Aphrodite Genetrix,” a Roman replica of which is in the Louvre. He has also been linked with a series of reliefs of dancing Maenads, such as the Roman copy now in the Metropolitan Museu...
Aphrodite of Cnidus (work by Praxiteles)
His most celebrated work was the “Aphrodite of Cnidus,” which the Roman author Pliny the Elder considered not only the finest statue by Praxiteles but the best in the whole world. The goddess is shown naked, a bold innovation at the time. From reproductions of this statue on Roman coins numerous copies have been recognized; the best known are in the Vatican Museum, Rome, and in the.....
Aphrodite, Temple of (ancient temple, Cnidus, Turkey)
...marble statue of the seated Demeter there. Later excavation revealed the axial plan of the ancient city, a few private dwellings, and numerous public buildings. The most significant of these is the Temple of Aphrodite, a circular Doric temple, excavated by Iris C. Love in 1970. At this site Love found the marble base and fragments of the famous statue of Aphrodite sculpted by Praxiteles in the....
Aphrodite Terra (Venusian surface feature)
the larger of two continent-sized highland areas (terrae) on the planet Venus. Aphrodite lies along Venus’s equator and extends from about longitude 60° E to 150° E. It is about twice the size of Ishtar Terra and comparable in surface area to South America....
Aphroditoidea (annelid)
any member of the superfamily Aphroditoidea (class Polychaeta, phylum Annelida), a group of widely distributed free-moving, segmented marine worms that possess dorsal scales. Scale worms range in size from 0.5 to 25 cm (about 0.2 to 10 inches). The superfamily is made up of several dozen genera and also includes the ...
Aphrophora (insect)
...occur in enormous numbers and secrete large amounts of spittle, which drips from tree branches like rain. The sugarcane froghopper (Tomaspis saccharina) is very destructive in Trinidad. Aphrophora species are serious pests of willow and pine. One group of froghoppers secretes small calcareous tubes that resemble snail shells and were once classified as snails by zoologists....
Aphthartodocetism (Christian heresy)
(Greek aphthartos, “incorruptible”), a Christian heresy of the 6th century that carried Monophysitism (“Christ had but one nature and that divine”) to a new extreme; it was proclaimed by Julian, bishop of Halicarnassus, who asserted that the body of Christ was divine and...
aphthartos (Christian heresy)
(Greek aphthartos, “incorruptible”), a Christian heresy of the 6th century that carried Monophysitism (“Christ had but one nature and that divine”) to a new extreme; it was proclaimed by Julian, bishop of Halicarnassus, who asserted that the body of Christ was divine and...
Aphthona flava (insect)
...and melon vines, E. hirtipennis attacks tobacco plants, and E. fuscula eats tomatoes and potatoes. The flea beetle Aphthona flava has been released in the United States and Canada as a biological control for the weed leafy spurge....
aphthous fever (animal disease)
a highly contagious viral disease affecting practically all cloven-footed domesticated mammals, including cattle, sheep, goats, and pigs. Wild herbivores such as bison, deer, antelopes, reindeer, and giraffes are also susceptible. The horse is resistant to the infection....
aphthous stomatitis (medical disorder)
a small, painful ulcer of the oral cavity. Canker sores are round, shallow, white ulcers on the inner surface of the cheek or lip. They are surrounded by an inflamed area and may reach 2.5 cm (1 inch) in size. Canker sores can occur in three forms: as one to five small lesions that heal within two weeks; as relatively large ...
Aphyocharax rubripinnis (fish)
freshwater fish, a species of characin....
Aphyosemion (fish genus)
any of a half dozen species of fishes in the genus Aphyosemion of the family Cyprinodontidae (order Atheriniformes). All are freshwater species of tropical Africa. They attain lengths of five centimetres (two inches). Female lyretails are drab olive or beige, but the males are brilliantly speckled and spotted with reds, yellows, greens, and blues. The tail is fan-shaped with extended filam...
Aphyosemion australe (fish)
...but the males are brilliantly speckled and spotted with reds, yellows, greens, and blues. The tail is fan-shaped with extended filaments at the top and bottom giving the appearance of a lyre. The Cape Lopez lyretail (A. australe), one of the first species to be imported, is a popular aquarium fish, as are the others. Lyretails belong to the killifish (q.v.) group....
API (computer programming)
sets of standardized requests that allow different computer programs to communicate with each other....
API gravity scale (chemical measurement)
The widely used American Petroleum Institute (API) gravity scale is based on pure water, with an arbitrarily assigned API gravity of 10°. Liquids lighter than water, such as oil, have API gravities numerically greater than 10. Crude oils below 20° API gravity are usually considered heavy, whereas the conventional crudes with API gravities between 20° and 25° are regarde...
api, Le (work by Rucellai)
...showed his wit and stylistic skill. Didactic poetry, already cultivated by humanist writers, was also continued during this period, chiefly by Giovanni Rucellai, who recast in Le api (1539; “The Bees”) the fourth book of the Roman poet Virgil’s Georgics, and by Luigi Alamanni, in six books on agriculture and rustic life called ...
Api, Mount (mountain, Banda Islands, Indonesia)
...deep seas and vary in size from tiny atolls to the large mountainous island of Ceram, which covers more than 6,600 square miles (17,100 square km). After having lain dormant for more than 80 years, Mount Api, an active volcano in the Banda Islands, violently erupted in 1988, causing total evacuation of the surrounding areas—including nearby islands. Ambon island has frequent earthquakes....
Api-Api (Malaysia)
city of Sabah state, East Malaysia, on the northwest coast of Borneo. Although razed by bombing during World War II (1939–45), the site was chosen in 1946 for the new capital of British North Borneo (now Sab...
Apia (Samoa)
town, port, and capital (since 1959) of Samoa. It is located on the northern coast of Upolu Island, in the South Pacific Ocean. The Apia Observatory, the legislative council chambers, and a broadcasting station are on the Mulinuu Pen...
Apia (atoll, Kiribati)
coral atoll of the Gilbert Islands, part of Kiribati, in the west-central Pacific Ocean. Comprising six islets in the northern Gilberts, the atoll has a lagoon (16 miles by 5 miles [26 km by 8 km]) that provides sheltered anchorage. The islets of Abaiang are Teirio, Nuo...
Apiaceae (plant family)
the parsley family, in the order Apiales, comprising between 300 and 400 genera of plants distributed throughout a wide variety of habitats, principally in the north temperate regions of the world. Most members are aromatic herbs with alternate, feather-divided leaves that are sheathed at the base. The flowers are often arran...
Apiales (plant order)
carrot order of flowering plants, containing some 5,500 species. The main families in the order are Apiaceae (parsley family) and Araliaceae (gin...
Apianus, Petrus (German geographer)
...textbooks of geography, astronomy, history, and natural sciences, all illustrated with maps and figures, first appeared in the 16th century. One of the earliest and best known was that of Petrus Apianus in 1524, the popularity of which extended to 15 more editions. That of Sebastian Münster, published in 1544, was larger and remained authoritative and in demand until the end of......
Apiarius (Roman priest)
Even though he confirmed Innocent’s judgment, Zosimus disturbed the African episcopate in a new controversy by espousing the cause of a disreputable priest called Apiarius, who had been excommunicated by Bishop Urbanus of Sicca Veneria. Defying African canon law, Zosimus dispatched legates to Africa with orders that included reorganizing the method of appeal between Africa and Rome and a th...
apical consonant (linguistics)
The third important sound change occurred in the South-Central Dravidian languages. In this group the apical consonants (comprising the alveolar and retroflex consonants) that were in the middle of a word were pushed to the initial (first) position. When the word began with a vowel and was followed by an apical consonant and a vowel, V1CapicalV2, it became a......
apical meristem (plant anatomy)
Roots grow in length only from their ends. The very tip of the root is covered by a protective, thimble-shaped root cap. Just behind the root cap lies the apical meristem, a tissue of actively dividing cells. Some of the cells produced by the apical meristem are added to the root cap, but most of them are added to the region of elongation, which lies just above the meristematic region. It is in......
apical zone (hypha)
The hypha may be roughly divided into three regions: (1) the apical zone about 5–10 micrometres (0.0002–0.0004 inch) in length, (2) the subapical region, extending about 40 micrometres back of the apical zone, which is rich in cytoplasmic components, such as nuclei, Golgi apparatus, ribosomes, mitochondria, the endoplasmic reticulum, and vesicles, but is devoid of vacuoles, and (3).....
Apicius (Roman merchant)
Another famous gourmet of the ancient world was Apicius, a wealthy Roman merchant of the reign of Tiberius (ad 14–37). Apicius’ colossal banquets eventually drove him to bankruptcy and suicide, but he left behind a cookbook so prized that it has been preserved, in numerous editions, down to the 20th century....
apico alveolar articulation (phonetics)
...lip shape, and height of the larynx used to produce a vowel. The primary articulation may still permit some range of movement for other articulators not involved in its formation. For example, an “apico alveolar” articulation involves the tip of the tongue but leaves the lips and back of the tongue free to produce some degree of further stricture in the vocal tract. This latter is...
Apicomplexa (protozoan)
any protozoan of the (typically) spore-producing phylum Apicomplexa, which is called by some authorities Sporozoa. All apicomplexans are parasitic and lack contractile vacuoles and locomotor processes. Apicomplexans live within the body cavities or the cells of almost every kind of animal, including other apicomplexans. Some genera are pathogen...
apicomplexan (protozoan)
any protozoan of the (typically) spore-producing phylum Apicomplexa, which is called by some authorities Sporozoa. All apicomplexans are parasitic and lack contractile vacuoles and locomotor processes. Apicomplexans live within the body cavities or the cells of almost every kind of animal, including other apicomplexans. Some genera are pathogen...
apiculture
care and management of colonies of honeybees. They are kept for their honey and other products or their services as pollinators of fruit and vegetable blossoms or as a hobby. The practice is widespread: honeybees are kept in large cities and villages, on farms and rangelands, in forests and deserts, from the Arctic and Antarctic to the Equator. Honeybees are not domesticated. Th...
Apidae (bee family)
...noted for their elaborate nest structures; Anthophoridae (including carpenter bees and cuckoo bees), a large family that includes three subfamilies that were once considered to be subfamilies of Apidae; and Apidae (bumblebees, honeybees, and digger, or mining, bees)....
Apidium (primate)
...Qatrani formations, has come the first evidence of the emerging Catarrhini. A number of different genera have been described from Fayum, including Catopithecus, Proteopithecus, Apidium, Qatrania, Propliopithecus, Oligopithecus, Parapithecus, and Aegyptopithecus. The first two of these, together with some other primates of uncertain......
apilum (Mesopotamian religion)
In Mari, the two key words for prophet are muḫḫum (an ecstatic, a frenzied one) and āpilum (the one who responds). Both may be connected with the cult, but there are incidents indicating that the muḫḫum was not bound to the cultic setting but received his message in a direct revelation from his god. The āpilum......
Apinagia (plant genus)
The principal genera are Apinagia (50 species, tropical South America), Ledermanniella (43 species, tropical Africa and Madagascar), Rhyncholacis (25 species, northern tropical South America), Marathrum (25 species, Central America and northwestern tropical South America), Podostemum (17 species, worldwide tropics and subtropics), Dicraea (12 species,......
Apion, Ptolemy (ruler of Cyrenaica)
ruler of Cyrenaica who separated it from Egypt and in his will bequeathed the country to Rome....
Apiru (people)
...parents were from the tribe of Levi, one of the groups in Egypt called Hebrews. Originally the term Hebrew had nothing to do with race or ethnic origin. It derived from Habiru, a variant spelling of Ḫapiru (Apiru), a designation of a class of people who made their living by hiring themselves out for various services. The biblical Hebrews had been in Egypt for generations, but......
Apis (Egyptian god)
in ancient Egyptian religion, sacred bull deity worshipped at Memphis. The cult of Apis originated at least as early as the 1st dynasty (c. 2925–c. 2775 bce). Like other bull deities, Apis was probably at first a fertility god concerned with the propagation of grain and herds, but he became associated with Ptah...
Apis (constellation)
constellation in the southern sky at about 13 hours right ascension and 70° south in declination. Its brightest star is Alpha Muscae, with a magnitude of 2.7. This constellation was invented by Pieter Dircksz Keyser, a navigator who joined the first Dutch expedition to the East Indies...
Apis (Serbian army officer)
Serbian army officer and conspirator, leader of the Serbian secret society Crna Ruka (“Black Hand”)....
Apis (insect)
any of a group of insects in the family Apidae (order Hymenoptera) that in a broad sense includes all bees that make honey. In a stricter sense, honeybee applies to any one of four members of the genus Apis—and usually only the single species, Apis mellifera, the domestic honeybee. This s...
Apis dorsata
...or the western honeybee. All other Apis species are confined to Asia. A. florea, the little honeybee, occurs in central Asia, where it builds its nests in trees. A. dorsata, the giant honeybee, occurs in India, Indonesia, and central China and sometimes builds combs nearly three metres (more than nine feet) in diameter. A. indica, the Eastern honeybee, is domesticate...
Apis florea (bee)
...Apis mellifera, the domestic honeybee. This species is also called the European domestic bee or the western honeybee. All other Apis species are confined to Asia. A. florea, the little honeybee, occurs in central Asia, where it builds its nests in trees. A. dorsata, the giant honeybee, occurs in India, Indonesia, and central China and sometimes builds combs nearly......
Apis indica
...in trees. A. dorsata, the giant honeybee, occurs in India, Indonesia, and central China and sometimes builds combs nearly three metres (more than nine feet) in diameter. A. indica, the Eastern honeybee, is domesticated in parts of Asia. There are also a number of races, subspecies, and strains of Apis species....
Apis mellifera (insect)
In 2008 agricultural researchers sought to determine the cause of a mysterious disorder that was destroying colonies of Apis mellifera honeybees. The malady, called colony collapse disorder (CCD), was threatening honeybee populations across the United States, where they were essential for the pollination of many commercially important crops. The disorder had also been reported elsewhere,......
Apithy, Sourou-Migan (president of Benin)
...on August 1, 1960. During the period of decolonization, the nationalist movement in Dahomey became fragmented, with the emergence of three regionally based political parties—led by Sourou-Migan Apithy (president in 1964–65), Justin Ahomadégbé (1972), and Hubert Maga (1960–63 and 1970–72), drawing their principal support respectively from......
Apium graveolens (plant)
(species Apium graveolens), herb of the family Apiaceae (Umbelliferae). Native to the Mediterranean areas and the Middle East, celery was used as a flavouring by the ancient Greeks and Romans and as a medicine by the ancient ...
Apium graveolens rapaceum (herb)
Type of celery (Apium graveolens, variety rapaceum) grown for its knobby edible root, which is used as a raw or cooked vegetable. Originally cultivated in the Mediterranean and in northern Europe, it was introduced into Britain in the 18th century....
Apizaco (Mexico)
city, central Tlaxcala estado (state), east-central Mexico. It lies at 7,900 ft (2,400 m) above sea level in the cool Apizaco valley of the Sierra Madre Oriental. Formerly known as Barrón Escandón, ...
APL (computer language)
Computer programming language based on (and named with the initials of) the book A Programming Language, by Kenneth E. Iverson of IBM (1962). It has been adapted for use in many different computers and fields because of its concise syntax. Statements are expressed with simple nota...
APL (political party, Albania)
In early 2010 the opposition Socialist Party of Albania (PS) continued the boycott of the Albanian parliament that it had begun in September 2009 after the government rejected party leader Edi Rama’s demand for a recount of the general election of June 28, 2009. On February 25, responding to mediation efforts by the Council of Europe, the 64 PS deputies returned to the parliament. Nonethele...
apl.de.ap (American musician)
...(byname of William James Adams, Jr.; b. March 15, 1975Los Angeles, Calif., U.S.) and apl.de.ap (byname of Allan Pineda Lindo; b. Nov. 28, 1974Angeles City, Pampanga, Phil.)...
APLA (South African military organization)
...Democratic Front’s more practical nonracial politics. However, after the unbanning of both the ANC and the PAC in 1990, the aggressively antiwhite postures of the PAC’s military wing (now named the Azanian People’s Liberation Army; APLA), with its slogan of “One settler, one bullet,” became popular. The APLA perpetrated several massacres between 1991 and 1994,...
Aplacophora (mollusk class)
Annotated classification...
Aplahoué plateau (plateau, Benin)
The Benin plateaus, four in number, are to be found in the environs of Abomey, Kétou, Aplahoué (or Parahoué), and Zagnanado. The plateaus consist of clays on a crystalline base. The Abomey, Aplahoué, and Zagnanado plateaus are from 300 to 750 feet high, and the Kétou plateau is up to 500 feet in height....
aplanospore (biology)
...red algae produce monospores (walled, nonflagellate, spherical cells) that are carried by water currents and upon germination produce a new organism. Some green algae produce nonmotile spores called aplanospores. In contrast, zoospores lack true cell walls and bear one or more flagella. These flagella allow zoospores to swim to a favourable environment, whereas monospores and aplanospores have....
aplastic anemia (pathology)
disease in which the bone marrow fails to produce an adequate number of blood cells. There may be a lack of all cell types—white blood cells (leukocytes), red blood cells (erythrocytes), and platelet...
aplastic crisis (pathology)
...the constantly increased rate of their destruction. Parvovirus is known to cause this transient cessation of erythropoiesis, and the development of severe anemia under these circumstances is termed aplastic crisis. Removal of the spleen, which always is enlarged, cures the anemia by eliminating the site of sequestration and destruction of the red blood cells but does not prevent hereditary......
aplite (geology)
any intrusive igneous rock of simple composition, such as granite composed only of alkali feldspar, muscovite mica, and quartz; in a more restricted sense, uniformly fine-grained (less than 2 millimetres [0.08 inch]), light-coloured, intrusive igneous r...
Aplodinotus grunniens (fish)
...are the channel bass, or red drum (Sciaenops ocellatus), a large, reddish species of the western Atlantic Ocean; the white seabass (Atractoscion nobilis) of the eastern Pacific; the freshwater drum (Aplodinotus grunniens), a silvery, lake-and-river fish of the Americas; the kingfish, or whiting (Menticirrhus saxatilis), of the Atlantic, notable among drums in that......
Aplodontia rufa (rodent)
a muskrat-sized burrowing rodent found only in the Pacific Northwest of North America. Unlike the American and Eurasian beavers (genus Castor), the mountain beaver has an extremel...
Aplousobranchia (tunicate order)
Annotated classification...
Aplysia (gastropod genus)
...provide camouflage, or to inhibit the predator’s sense of smell. For example, the ink in cephalopods, the luminous cloud secreted by some deep-sea squids, and the purple fluid from the sea hare (Aplysia; a gastropod of the subclass Opisthobranchia) distract and confuse the predator and conceal the prey. Camouflage or frightening coloration are effective in protecting cuttlefishes,...
Aplysia californica (marine snail)
Elementary forms of learning and memory have been studied at a cellular level by analysis of the neuronal activity of the marine snail (Aplysia californica). This simple mollusk withdraws its gill and siphon in response to a mild tactile stimulus. The neural circuit for this reflex consists of a sensory component from the siphon that forms single-synapse junctions with motor......
Aplysia dactylomela (gastropod)
...flat plate, prominent tentacles (resembling rabbit ears), and a smooth or warty body. Sea hares eat large seaweeds, and all are simultaneous hermaphrodites. An example is the 10-centimetre (4-inch) spotted sea hare (Aplysia dactylomela), a ring-spotted green species living in grassy shallows of the Caribbean. Research involving sea hares has greatly increased the scientific understanding...
Aplysiidae (gastropod)
any marine gastropod of the family Aplysiidae (subclass Opisthobranchia, phylum Mollusca) that is characterized by a shell reduced to a flat plate, prominent tentacles (resembling rabbit ears), and a smooth or warty body. Sea hares eat large seaweeds, and all are simultaneous hermaphrodites. An example is the 10-centimetre (4-inch) spotted sea...
apnea (pathology)
...of ventilation. During sleep and anesthesia, lowering carbon dioxide levels three to four millimetres of mercury below values occurring during wakefulness can cause a total cessation of breathing (apnea)....
apneusis (physiology)
...is characterized by prolonged inspiratory activity that may last for several minutes. This type of breathing, which occasionally occurs in persons with diseases of the brain stem, is called apneustic breathing....
apneustic breathing (physiology)
...is characterized by prolonged inspiratory activity that may last for several minutes. This type of breathing, which occasionally occurs in persons with diseases of the brain stem, is called apneustic breathing....
APNI (political party, Northern Ireland, United Kingdom)
Northern Ireland’s oldest interdenominational party, a small, moderate party that represents middle-class interests primarily in the eastern areas of the province....
APO (political party, South Africa)
The Coloureds of the Cape and Transvaal also mobilized politically in the first nationwide black political organization, the African Political Organization (APO; later African People’s Organization), founded in 1902, which sought to unite Africans in opposition to the South Africa Act of 1909. The formation of a separate Coloured Affairs Department to some extent diverted Coloured political...
Apo Mayta (Inca leader)
...as the seventh emperor, ensuring a peaceful succession to the throne. Yahuar Huacac was never very healthy and apparently spent most of his time in Cuzco. His brothers Vicaquirao (Wika-k’iraw) and Apo Mayta (’Apu Mayta) were able military leaders and incorporated lands south and east of Cuzco into the Inca domain. Yahuar Huacac’s principal wife was apparently an Ayarmaca, i...
Apo, Mount (volcano, Philippines)
active volcano, south central Mindanao, 20 miles (32 km) west of Davao City; it is the highest point in the Philippines, rising to 9,692 feet (2,954 metres). Part of the Cordillera Central, it is covered by a forest of tall, tropical hardwoods; two subsidiary peaks nearly match its height. Mount Apo National Park, established in 1936, has an area of 199,819 acres (80,864 hectares); it is the home ...
APO-1 (protein)
...the cellular contents to leak out and the cell to die. The nongranular cytotoxic T cells often kill cells by inducing apoptosis, usually through the activation of a cell-surface protein called Fas. When a protein on the surface of the cytotoxic T cell interacts with the Fas protein on the target cell, Fas is activated and sends a signal to the nucleus of the target cell, thus initiating......
apoapsis (astronomy)
...or centre of attraction. The line of apsides, connecting the two points, is the major axis of the orbit. The point nearest the focus is the pericentre, or periapsis, and that farthest from it is the apocentre, or apoapsis. Specific terms can be used for individual bodies: if the Sun is the centre, the specific terms perihelion and aphelion are generally used; if the Earth, perigee and apogee......