(from the article "human cardiovascular system") ...form what is termed the azygous system, which serves as a connecting link between the superior and inferior vena cava. The terminal veins of this system are the azygous, hemiazygous, ...
(from the article "nervous system, human") ...the hypothalamus and on the dorsal surface of the internal capsule. The subthalamic region is traversed by fibres related to the globus pallidus. Discrete lesions of the subthalmic nucleus produce ...
any of a group of complex carbohydrates that, with other carbohydrates (e.g., pectins), surround the cellulose fibres of plant cells. The most common hemicelluloses contain xylans (many molecules of the ... [2 Related Articles]
any of a group of wormlike marine invertebrates closely related to both chordates and echinoderms and usually considered to constitute a phylum, the Hemichordata. The term Hemichordata-from the Greek hemi, ... [5 Related Articles]
(from the article "medicine, history of") ...Brunschwig, of Chicago, in 1937. Then, in 1960, Charles S. Kennedy, of Detroit, after a long discussion with Brunschwig, put into practice an operation that he had been considering for ...
(from the article "Miocene Epoch") ...and Merychippus are genera that represent great diversification and development. Also, the first dogs and bears appeared; the timing of the first emergence of the bear-dog Hemicyon occurs close to ...
(from the article "hedgehog") ...of India. The western European hedgehog inhabits forest margins, grasslands, scrub, hedgerows, and suburban gardens. It also has been introduced into New Zealand. The desert hedgehog (Hemiechinus aethiopicus) survives in ...
(from the article "nervous system disease") In hemifacial spasm repetitive twitching of one side of the face occurs. Irritation of the facial nerve as it leaves the brainstem appears to be the cause, and in many ...
(from the article "theatre") ...a throne on a round or square podium. New machines were added in the Hellenistic period, by which time the theatre had almost completely lost its religious basis. Among these ...
(from the article "coffee rust") the most devastating disease of coffee plants, caused by the fungus Hemileia vastatrix. Long known in coffee-growing areas of Africa, the Near East, India, Asia, and Australasia, rust was discovered ...
(from the article "malformation") ...to this type of malformation. Besides malformed individuals with rudimentary limbs (phocomelus; having "seal-like limbs"), others have incomplete or underdeveloped extremities (hemimelus, micromelus, ectromelus).peromelia
(from the article "insect") ...until the final molt, when the larva undergoes substantial changes in body form to become a winged adult with fully developed genitalia. These insects, termed hemimetabolous, are said to undergo ...
one of two minerals formerly called calamine in the U.S., a white silicate mineral that is an important zinc ore. A secondary mineral formed from the alteration of sphalerite, it ...
(from the article "Fischer, Hans") German biochemist who was awarded the Nobel Prize for Chemistry in 1930 for research into the constitution of hemin, the red blood pigment, and chlorophyll, the green pigment in plants.
(from the article ""Tom and Sally": the Jefferson-Hemings paternity debate") ...learned about the sexual escapades of their 20th-century presidents-Warren Harding, John Kennedy, and Bill Clinton were the chief offenders-there was the story of Thomas Jefferson and Sally Hemings. Until recently, ...
American novelist and short-story writer, awarded the Nobel Prize for Literature in 1954. He was noted both for the intense masculinity of his writing and for his adventurous and widely ... [17 Related Articles]
("MARGAUX"), U.S. model and actress--and the granddaughter of Ernest Hemingway--who was paid $1 million as the spokesperson for the Faberge fragrance Babe and made her film debut in 1976 in ...
(from the article "marine sediment") The sediments deposited on continental shelves and rises, frequently referred to as hemipelagic sediments, ordinarily accumulate too rapidly to react chemically with seawater. In most cases, individual grains thus retain ...
(from the article "reptile") ...that of the female. The male then discharges semen into the female's cloaca. In all other reptiles, males have either a penis (as in turtles [order Testudines] and crocodiles [order ...
(from the article "Anura") ...development; 37 genera and 630 species; adult length 1.7 to about 14 cm (0.7 to 5.5 inches); 4 subfamilies: Pelodryadinae (Australo-Papuan region), Phyllomedusinae (Central and South America), Hemiphractinae (Central and ...
(from the article "Anura") ...in the back, whereas in other genera, such as the Surinam toad (Pipa pipa) and its relatives, each egg occupies its own individual depression. In
paralysis of the muscles of the lower face, arm, and leg on one side of the body. The most common cause of hemiplegia is damage to the corticospinal tracts in ... [3 Related Articles]
(Greek: "half foot"), generally any bird of the suborder Turnices (order Gruiformes), which includes the plains wanderer (q.v.; family Pedionomidae), the button quail, and the lark quail (family Turnicidae), but ... [1 Related Articles]
(from the article "scorpion") 9 species, mostly in caves of the American Southwest and Mexico. 7 dangerous species of eastern Africa and southwestern Asia.7 species of...
(from the article "Anura") ...or absent. Larvae carried on backs of adults; Central and South America; 9 genera, about 162 species; adult length 1.5-5 cm (0.5-2 inches).No fossil record; 7 presacral vertebrae; vertebral ...
(from the article "sundial") Another early device was the hemispherical sundial, or hemicycle, attributed to the Greek astronomer Aristarchus of Samos about 280 BC. Made of stone or wood, the instrument consisted of a ...
(from the article "acoustics") ...The intensity of a spherical sound wave decreases in intensity at a rate of six decibels for each factor of two increase in distance from the source, as shown above. ...
(from the article "pentatonic scale") ...it is found, in different forms, in most of the world's music. The most widely known form is anhemitonic (without semitones; e.g., c-d-f-g-a-c'), the hemitonic form (with semitones; e.g., c-e-f-g-b-c') ...
any of about 14 species of coniferous evergreen trees comprising the genus Tsuga of the family Pinaceae, native to North America and central and eastern Asia. Some are important timber ... [2 Related Articles]
(from the article "Belgian literature") In the mid-1980s a number of younger prose writers gained attention. They include Kristien Hemmerechts, who wrote about loss and sexual tensions in an understated manner, the more philosophical Patricia ...
British actor, director, and producer (b. Nov. 18, 1941, Guildford, Surrey, Eng.-d. Dec. 3, 2003, Bucharest, Rom.), played the lead, a mod fashion photographer, in Michelangelo Antonioni's classic "swinging '60s" ...
(from the article "primate") ...found in the lemurs and lorises, several cellular layers separate the maternal and fetal bloodstreams and thus limit the passage of molecules of serum proteins. In the second type (hemochorial), ...
inborn metabolic defect characterized by an increased absorption of iron, which accumulates in body tissues. The clinical manifestations include skin pigmentation, diabetes mellitus, enlargement of the spleen and liver, cirrhosis, ... [2 Related Articles]
compound of the iron-containing pigment heme with a protein or other substance. The hemochromogens include hemoglobin, found in red blood cells, and the cytochromes, which are widely distributed compounds important ...
(from the article "circulation") Blood and coelomic fluid are often physically separated by the blood-vessel walls; where a hemocoel (a blood-containing body cavity) exists, however, blood rather than coelomic fluid occupies the cavity. The ...
(from the article "coloration") Copper-containing proteins called hemocyanins occur notably in the blood of larger crustaceans and of gastropod and cephalopod mollusks. Hemocyanins are colourless in the reduced, or deoxygenated, state and blue when ...
(from the article "circulation") Invertebrate blood may contain a number of cells (hemocytes) arising from the embryonic mesoderm. Many different types of hemocytes have been described in different species, but they have been studied ...
(from the article "erythrocyte") The erythrocyte develops in bone marrow in several stages: from a hemocytoblast, a multipotential cell in the mesenchyme, it becomes an erythroblast (normoblast); during two to five days of development, ...
iron-containing protein in the blood of many animals-in the red blood cells (erythrocytes) of vertebrates-that transports oxygen to the tissues. Hemoglobin forms an unstable, reversible bond with oxygen; in the ... [36 Related Articles]
(from the article "Number of amino acids per protein molecule") Hemoglobin is composed of a porphyrin compound (heme) and globin. Normal adult hemoglobin (Hb A) consists of globin containing two pairs of polypeptide chains, alpha (alpha) and beta (beta). A ...
(from the article "blood disease") ...contain alpha-chains, there is no increase in Hb F or Hb A1. The extra non-alpha-chains may combine into tetramers to form beta4 (hemoglobin H) or gamma4 (hemoglobin Bart). These tetramers ...
(from the article "hemoglobinopathy") ...some protection from the lethal effects of malaria, thereby allowing more persons to reach reproductive age. The most important of the hemoglobinopathies are sickle-cell anemia and thalassemia. Hemoglobin C (Hb ...
(from the article "hemoglobinopathy") Hemoglobin D is found mainly in people of Afghan, Pakistani, and northwestern Indian descent, but it also occurs in those of European ancestry. Hemoglobin D disease (two genes for Hb ...
(from the article "hemoglobinopathy") ...mainly in people of Afghan, Pakistani, and northwestern Indian descent, but it also occurs in those of European ancestry. Hemoglobin D disease (two genes for Hb D) may produce mild ...
(from the article "blood disease") ...occurs, but there may be combinations of hemoglobin abnormalities, or a hemoglobin abnormality may be inherited from one parent and thalassemia from the other. Thus, sickle-thalassemia and Hb E-thalassemia are ...
(from the article "blood disease") ...chains, alpha (alpha) and beta (beta). A minor fraction of normal adult hemoglobin consists of Hb A2, which contains alpha- and delta- (delta-) chains. A different hemoglobin (Hb F) is ...
(from the article "hemoglobinopathy") ...in a mild microcytic (small red blood cell) anemia. Hemoglobin E-thalassemia disease (one gene for Hb E, one gene for thalassemia) is severe and clinically closely resembles thalassemia major. Hemoglobin ...
(from the article "race") ...has been another major factor in the evolution of human diversity, and some of the most important of human genetic variations reflect differences in immunities to diseases. The sickle cell ...
(from the article "Haldane, John Scott") ...procedures for studying the physiology of breathing and the physiology of the blood and for the analysis of gases consumed or produced by the body. Among his most widely used ...
any of a group of disorders caused by the presence of variant hemoglobin in the red blood cells. Variant-hemoglobin disorders occur geographically throughout the Old World in a beltlike area ... [1 Related Articles]
(from the article "insect") ...to increase the capacity of the rectum for reabsorbing water and salts. The products of digestion, discharged into the hemocoele, or general body cavity, are transported by the circulatory fluid, ...
breakdown or destruction of red blood cells so that the contained hemoglobin is freed into the surrounding medium. Antibody (lysin) attaches to the red cell but cannot cause bursting in ... [5 Related Articles]
(from the article "blood disease") Destruction of red cells at a rate substantially greater than normal, if not compensated for by accelerated red cell production, causes hemolytic anemia. Increased red cell destruction is recognized by ...
(from the article "blood group") ...Denis, court physician to King Louis XIV, had also been transfusing lambs' blood into human subjects and described what is probably the first recorded account of the signs and symptoms ...
(from the article "Health and Disease") ...The typical symptoms-severe bloody diarrhea and abdominal cramps-developed within three to four days of eating the contaminated spinach. About 16% of the patients developed hemolytic uremic syndrome, a type of ...
(from the article "American literature") ...who won acclaim for Drown (1996), a collection of stories, and whose novel The Brief Wondrous Life of Oscar Wao (2007) won a Pulitzer Prize; and the Bosnian immigrant Aleksandar ...
hereditary bleeding disorder caused by a deficiency of a substance necessary for blood clotting (coagulation). In hemophilia A, the missing substance is factor VIII. The increased tendency to bleeding usually ... [9 Related Articles]
(from the article "Common hereditary and acquired coagulation disorders") The best-known coagulation disorder is hemophilia, which is due to an inherited defect transmitted by the female but manifested almost exclusively in the male. The most common form of hemophilia, ...
(from the article "Common hereditary and acquired coagulation disorders") ...absence of the coagulation protein factor VIII (antihemophilic globulin). Of persons with hemophilia, approximately 85 percent have factor VIII deficiency. The next most common form of hemophilia, hemophilia B, is ...
(from the article "respiratory disease") The organism Hemophilus influenzae is commonly isolated from the sputum of patients with chronic bronchitis during acute exacerbations of infection and is an important cause of pneumonia ...
(from the article "Bayliss, Sir William Maddock") ...where he became professor of general physiology (1912-24). Their study in the 1890s of nerve-controlled contraction and dilation of blood vessels resulted in the development of an improved hemopiezometer (a ...
(from the article "cytochrome") ...hemoprotein cell components that, by readily undergoing reduction and oxidation (gain and loss of electrons) with the aid of enzymes, serve a vital function in the transfer of energy within ...
(from the article "tuberculosis") ...lung, the lesion consists of a collection of dead cells in which tubercle bacilli may be seen. This lesion may erode a neighbouring bronchus or blood vessel, causing the patient ...
(from the article "animal disease") ...part, which is referred to by the term congestion, or hyperemia, occurs during inflammation; a diminished blood flow to tissues is referred to by the term ischemia, or a local ...
(from the article "Ebola") virus of the family Filoviridae that is responsible for a severe and often fatal viral hemorrhagic fever; outbreaks in primates such as gorillas and chimpanzees as well as humans have ...
(from the article "nutritional disease") ...of vitamin K across the placenta, newborn infants in developed countries are routinely given the vitamin intramuscularly or orally within six hours of birth to protect against a condition known ...
(from the article "hantavirus") There are several different hantaviruses, each with its specific rodent carrier, and they cause two basic groups of disease. The first group is known as hemorrhagic fever with renal syndrome ...
(from the article "nervous system disease") Hemorrhagic strokes, in which a blocked vessel bleeds, are usually due to small-vessel disease in individuals with high blood pressure. Such intracerebral hemorrhage occurs most often in the deep white ...
mass formed by distension of the network of veins under the mucous membrane that lines the anal channel or under the skin lining the external portion of the anus. A ... [5 Related Articles]
(from the article "respiratory disease") ...but its cause is not fully understood. Pulmonary hemorrhage also occurs as part of a condition known as pulmonary hemosiderosis, which results in the accumulation of the iron-containing substance hemosiderin ...
(from the article "blood") The blood is contained under pressure in a vascular system that includes vast areas of thin and delicate capillary membranes. Even the bumps and knocks of everyday life are sufficient ...
(from the article "surgery") During an operation, hemostasis (the arresting of bleeding) is achieved by use of the hemostat, a clamp with ratchets that grasps blood vessels or tissue; after application of hemostats, suture ...
collection of a bloody fluid in the pleural cavity, between the membrane lining the thoracic cage and the membrane covering the lung. Hemothorax may result from injury or surgery, especially ...
(from the article "venom") ...(characterized by such symptoms as muscle cramps, twitching, vomiting, and convulsions) or nervous depression (with such symptoms as paralysis and weakening or arrest of respiration and heartbeat). Hemotoxins affect the ...
(from the article "coloration") Pale-green pigment, hemovanadin, is found within the blood cells (vanadocytes) of sea squirts (Tunicata) belonging to the families Ascidiidae and Perophoridae. The biochemical function of hemovanadin, a strong reducing agent, ...
(species Cannabis sativa), plant of the family Cannabaceae and its fibre, one of the bast fibre group. The plant is also grown for its seed, which contains ... [9 Related Articles]
(from the article "stage design") ...fly loft) by means of mechanical hoists. There are two main types of flying systems: hand-operated and machine-driven. Hand-operated systems can be further subdivided into two types: rope-set, or hemp, ...
German-born American philosopher, formerly a member of the Berlin school of logical positivism, a group that viewed logical and mathematical statements as revealing only the basic structure of language, but ... [3 Related Articles]
U.S. saxophonist and composer (b. c. 1940, Fort Worth, Texas--d. April 2, 1995, New York, N.Y.), elicited a varied, reedy sound that was punctuated by rhythmic improvisations and produced compositions ...
town (township), Nassau county, New York, U.S. Situated in the west-central part of Long Island, it comprises 22 incorporated villages and 34 unincorporated communities. The city of Long Beach fronts ...
(from the article "Akbar") Humayun had barely established his authority when he died, in 1556. Within a few months his governors lost several important places, including Delhi itself, to Hemu, a Hindu minister who ...
(from the article "China") In the region of the lower Yangtze River (Chang Jiang), the Hemudu site in northern Zhejiang has yielded caldrons, cups, bowls, and pot supports made of porous, charcoal-tempered black pottery. ...
(from the article "agricultural sciences, the") ...decades of intensive selection and crossbreeding starting in the 1950s. Swine now yield more lean pork, grow faster, and require less feed to reach market weight than before. By the ...
(from the article "harrier") The best-known harrier is the hen harrier (British), usually called marsh hawk in the United States (Circus cyaneus), which breeds in temperate and boreal regions throughout the Northern Hemisphere and ...
(from the article "Polyporales") ...States. Dryad's saddle (P. squamosus) produces a fan- or saddle-shaped mushroom. It is light coloured with dark scales, has a strong odour, and grows on many deciduous trees. The edible ...
(from the article "Celtic literature") The poems associated with the name Llywarch Hen are the verse remains of at least two sagas composed toward the middle of the 9th century by unknown poets of Powys, ...
(from the article "hen-and-chickens") any of a number of succulent plants of the genera Echeveria and Sempervivum, in the family Crassulaceae; members of the latter genus are commonly known as houseleeks.common houseleekCommon ...
(from the article "Nisibis, School of") The Nestorian theology of the school, however, was undermined by the administration of Henana (c. 570-c. 609), who preferred Origen (a Christian theologian who flourished in the early 3rd century) ...
(from the article "Deffand, Marie de Vichy-Chamrond, Marquise du") ...whose mistress she became. She was frequently seen at Sceaux, where the Duchess du Maine held court amid a brilliant company that included Fontenelle, the Marquise de Lambert, Voltaire, and ...
(Hyoscyamus niger), highly toxic plant of the family Solanaceae indigenous to Great Britain and found growing wild in waste places and on rubbish heaps. It also occurs in central and ... [1 Related Articles]
group of 13 meteorite craters in a desert area 8 mi (13 km) west-southwest of Henbury, Northern Territory, central Australia, within the Henbury Meteorite Conservation Park. The craters, recognized in ...
American designer (b. June 29, 1908, Cedar Rapids, Iowa-d. Feb. 5, 2004, Burbank, Calif.), was closely associated with the Disney brand, designing theme parks, providing sketches for motion pictures (he ...
American physician who with Edward C. Kendall in 1948 successfully applied an adrenal hormone (later known as cortisone) in the treatment of rheumatoid arthritis. With Kendall and Tadeus Reichstein of ... [2 Related Articles]
(from the article "Armenian massacres") ...encouraged by Russia, began promoting Armenian territorial autonomy. As the movement grew, various political groups were organized, culminating in the formation of two revolutionary parties called Henchak ("The Bell") and ...
(from the article "Performing Arts") ...and the Tafelmusik Baroque Orchestra and Chamber Choir, while Jean-Philippe Rameau's Les Indes galantes (Opus Arte) was given a fanciful reading by William Christie and Les Arts Florissants. Herbert Henck ...
amateur astronomer who found the fifth and sixth minor planets to be discovered. Professional astronomers had largely given up the search for asteroids in 1816, when four were known. Hencke, ... [1 Related Articles]
