metabolism: Pyrimidine ribonucleotides: …yield the parent pyrimidine nucleotide, uridylic acid (UMP; reaction [73]).

metabolism: Fragmentation of other sugars: …reactions requiring as a coenzyme uridine triphosphate (UTP). Fructose may also be phosphorylated in animal cells through the action of hexokinase [1], in which case fructose 6-phosphate is the product, or in liver tissue via a fructokinase that gives rise to fructose 1-phosphate [17]. ATP supplies the phosphate group in…

metabolism: Pyrimidine ribonucleotides: …yield the parent pyrimidine nucleotide, uridylic acid (UMP; reaction [73]).

Uriel, in the Jewish and Christian Apocrypha and Pseudepigrapha, a leading angel, sometimes ranked as an archangel with Michael, Gabriel, and Raphael. Because his name in Hebrew means “fire of God” or “light of God,” he has been variously identified in Jewish traditions as an angel of thunder and

Karl Gutzkow: …and topical satirical comedy; and Uriel Acosta (1846), which uses the story of the martyrdom of that forerunner of Spinoza to make a plea for religious freedom. By this time he had published the novel Blasedow und seine Söhne (1838; “Blasedow and His Sons”), a humorous satire on the educational…

André Gide: Symbolist period: His works “Narcissus” (1891), Le Voyage d’Urien (1893; Urien’s Voyage), and “The Lovers’ Attempt” (1893) belong to this period.

feast: The significance of seasonal renewal in ancient Mesopotamia: …removed, and the priest (urigallu) hit him in the face and enjoined him to pray for the forgiveness of his sins and the sins of his people. After a profession of innocence, the priest absolved the king, restored his regal insignia, and performed ceremonies with the king to ensure…

religious dress: Early sacerdotal dress: …which the divinatory devices of Urim and Thummim were kept. The book of Exodus specifies that it was to be woven of golden and linen threads dyed blue, purple, and scarlet (28:15). Because of its oracular function, it was called the “breastpiece of judgment.” On the face of the breastplate…

urinalysis, laboratory examination of a sample of urine to obtain clinical information. Most of the substances normally excreted in the urine are metabolic products dissolved or suspended in water. A deviation from normal in the concentration of urinary constituents or the abnormal presence of

urinary bladder, in most vertebrates, except birds, organ for the temporary storage of urine from the kidneys, connected to the kidneys by means of tubular structures called ureters. A urinary bladder is present in fish as an expansible part of the urinary duct, in amphibians and bladder-possessing

fluke: The urinary blood fluke (S. haematobium), which lives in the veins of the urinary bladder, occurs mainly in Africa, southern Europe, and the Middle East. Eggs, laid in the veins, break through the vein wall into the bladder and are voided during urination. The larval fluke…

renal system disease: Disorders of urine flow: Incontinence, the involuntary passage of urine (or feces), may be due to a faulty nerve supply, which either leaves the sphincters relaxed or allows them to be overcome by distension of the bladder. Comatose and disturbed patients, especially among the elderly, are commonly incontinent. Apart…

schistosomiasis: Types and process of infection: (3) Vesical, or urinary, schistosomiasis is caused by S. haematobium, found throughout Africa and the Middle East.

annelid: Excretory system: The basic units of the annelid excretory system are either protonephridia, which have tubules (solenocytes) that end blindly within cells, contain flagella (whiplike projections), and are joined to a common duct that drains to the outside; or metanephridia, which are funnel-shaped structures containing…

annelid: Excretory system: The basic units of the annelid excretory system are either protonephridia, which have tubules (solenocytes) that end blindly within cells, contain flagella (whiplike projections), and are joined to a common duct that drains to the outside; or metanephridia, which are funnel-shaped structures containing…

urinary tract infection (UTI), in humans, inflammation of the renal system characterized by frequent and painful urination and caused by the invasion of microorganisms, usually bacteria, into the urethra and bladder. Infection of the urinary tract can result in either minor or major illness. For

urinary tract obstruction, blockage or constriction at any point in the urinary tract that impedes the normal flow of urine and causes urine to be retained in the bladder or kidneys. When an obstruction causes urine to become backed up into the kidneys, the condition is known as hydronephrosis.

urination, the process of excreting urine from the urinary bladder. Nerve centres for the control of urination are located in the spinal cord, the brainstem, and the cerebral cortex (the outer substance of the large upper portion of the brain). Both involuntary and voluntary muscles are involved.

urine, liquid or semisolid solution of metabolic wastes and certain other, often toxic, substances that the excretory organs withdraw from the circulatory fluids and expel from the body. The composition of urine tends to mirror the water needs of the organism. Freshwater animals usually excrete

urogenital system, in vertebrates, the organs concerned with reproduction and urinary excretion. Although their functions are unrelated, the structures involved in excretion and reproduction are morphologically associated and often use common ducts. The major structures of the urinary system in

Leon Uris was an American novelist known for panoramic, action-filled works such as the World War II novel Battle Cry (1953) and Exodus (1958), which deals with the struggle to establish and defend the state of Israel. During World War II, Uris dropped out of high school to join the Marine Corps.

Leon Uris was an American novelist known for panoramic, action-filled works such as the World War II novel Battle Cry (1953) and Exodus (1958), which deals with the struggle to establish and defend the state of Israel. During World War II, Uris dropped out of high school to join the Marine Corps.

Urizen, character in the mythology of William Blake. A godlike figure, Urizen personifies reason and law, and Blake believed him to be the true deity worshipped by his contemporaries. Blake first told Urizen’s story, the struggle against the chaos caused by the loss of a true human spirit, in the

Arabic literature: Categories and forms: The urjūzah (a poem composed in rajaz) was also utilized for verbal display and other types of didactic and even obscene poetry.

Hattusilis III: …overthrowing his nephew Urhi-Teshub (Mursilis III).

URL, compact string of numbers, letters, and symbols that a computer uses to find a resource on a network and act upon it. URLs are often colloquially referred to as Web addresses, or simply addresses, since Web pages are the most common resources that users employ URLs to find. However, all files

Brian Urlacher is an American professional gridiron football player known for his aggressive play and hard-hitting tackling. In his senior year of high school, in Lovington, New Mexico, Urlacher played both wide receiver and safety on a team that went 14–0 and won the state football championship.

Brian Urlacher is an American professional gridiron football player known for his aggressive play and hard-hitting tackling. In his senior year of high school, in Lovington, New Mexico, Urlacher played both wide receiver and safety on a team that went 14–0 and won the state football championship.

Gil de Siloé was recognized as the greatest Spanish sculptor of the 15th century. His origins are still a matter of dispute. The many names by which Gil is known are evidence of the confusion surrounding his origin. Urliones, or Urlienes, probably refers to Orléans, and Emberres, or Amberes,

Gil de Siloé was recognized as the greatest Spanish sculptor of the 15th century. His origins are still a matter of dispute. The many names by which Gil is known are evidence of the confusion surrounding his origin. Urliones, or Urlienes, probably refers to Orléans, and Emberres, or Amberes,

Protestantism: Germany: J.A. Urlsperger (1728–1806) sought to promote piety by organizing the Christentumsgesellschaft (“A Society for Christianity”), the German counterpart of the British Society for Promoting Christian Knowledge. Out of it grew the Basel Mission Society. G.C. Storr (1746–1804) and J.F. Flatt (1759–1821) represented the “Old Tübingen…

Austronesian languages: Major subgroups: …which is known today as Proto-Oceanic. The Oceanic hypothesis maintains that all Austronesian languages east of a line that runs through Indonesian New Guinea at approximately 138° E longitude—except for Palauan and Chamorro of western Micronesia—are descended from a single protolanguage spoken many generations after the initial breakup of Proto-Austronesian…

Orūmīyeh, city, capital of West Āz̄arbāyjān province, northwestern Iran. It lies just west of Lake Urmia on a large fertile plain that yields grains, fruits, tobacco, and other crops. The population is mainly Azeri and Kurdish, with Assyrian and Armenian minorities. The remains of ancient

Lake Urmia, lake in northwestern Iran that is the largest lake in the Middle East. It covers an area that varies from 2,000 to 2,300 square miles (5,200 to 6,000 square km). Like the Dead Sea, it is remarkable for the extreme salinity of its waters. Since 1967 it has enjoyed the status of a wetland

polytheism: The nature of polytheism: …the early 20th century an Urmonotheismus, or “original monotheism,” which later became overlaid by polytheism. Like all other theories of religious origins, this theory is speculative and unverifiable. More promising are attempts by sociologists and social anthropologists to penetrate to the uses and significance of the gods in particular societies.

utilitarianism: Utilitarianism since the late 19th century: …utilitarian by another Oxford philosopher, J.O. Urmson; and by the analysis by John Rawls, a Harvard political philosopher, of the significance for utilitarianism of two different conceptions of moral rules. “Act” utilitarianism, on the other hand, was defended by J.J.C. Smart, a British-Australian philosopher.

Urnfield culture: The Urnfield culture first appeared in east-central Europe and northern Italy; from the 12th century bc onward, however, the use of urn cemeteries, or urnfields, gradually spread to Ukraine, Sicily, Scandinavia, and across France to the Iberian peninsula—a movement perhaps associated with folk migrations. In most…

top moss, (Physcomitrium pyriforme), a common species of urn moss formerly known as P. turbinatum. The common name derives from the top-shaped capsules, which open by a small lid at the tip to release the spores. Physcomitrium is a genus of about 80 species in the family Funariaceae of the subclass

urn moss, any plant of the genus Physcomitrium (subclass Bryidae), characterized by urn-shaped or top-shaped capsules (spore cases) with lobed, hoodlike coverings. Fewer than 10 of the 68 species are native to North America. The most common is P. pyriforme, sometimes called top moss, about 2.5 cm

measurement system: Greeks and Romans: sextarius, congius, urna, and amphora for liquids. Since all of these were based on the sextarius and since no two extant sextarii are identical, a mean generally agreed upon today is 35.4 cubic inches, or nearly 1 pint (0.58 litre). The hemina, or half-sextarius, based on this…

Urnfield culture: The Urnfield culture first appeared in east-central Europe and northern Italy; from the 12th century bc onward, however, the use of urn cemeteries, or urnfields, gradually spread to Ukraine, Sicily, Scandinavia, and across France to the Iberian peninsula—a movement perhaps associated with folk migrations. In most…

Urnfield culture, a Late Bronze Age culture of Europe, so called because of the custom of placing the cremated bones of the dead in urns. The Urnfield culture first appeared in east-central Europe and northern Italy; from the 12th century bc onward, however, the use of urn cemeteries, or urnfields,

Guatemala: Civil war years: …in the formation of the Guatemalan National Revolutionary Unity (Unidad Revolucionario Nacional Guatemalteco; URNG). A series of attempted military coups were put down by the defense minister, Gen. Héctor Alejandro Gramajo. Labour and peasant unrest also increased during the Cerezo presidency. Some painful economic progress was made, but the insurgency…

Pridoli Series: …(a type of marine plankton), Urnochitina urna and Fungochitina kosovensis, first occur at or just above the base of the series. The earliest known simple vascular land plants, of the genus Cooksonia, typically occur in the lower portions of the Pridoli Series in many parts of the world. The Pridoli…

renal system: Volume and composition: …jaundice, particularly the obstructive variety; urobilin is greatly increased in certain diseases such as cirrhosis of the liver.

tunicate, any member of the subphylum Tunicata (Urochordata) of the phylum Chordata. Small marine animals, they are found in great numbers throughout the seas of the world. Adult members are commonly embedded in a tough secreted tunic containing cellulose (a glucose polysaccharide not normally

tunicate, any member of the subphylum Tunicata (Urochordata) of the phylum Chordata. Small marine animals, they are found in great numbers throughout the seas of the world. Adult members are commonly embedded in a tough secreted tunic containing cellulose (a glucose polysaccharide not normally

renal system: Volume and composition: …clear yellow from the pigment urochrome, an end product of protein metabolism. There are also traces of other pigments: urobilin and uroerythrin. The colour may be influenced as well by vitamins, food dyes, beetroot, and certain drugs.

gastropod: Classification: …Indies and Central America (Urocoptidae). Suborder Aulacopoda A group of 3 superfamilies. Superfamily Succineacea A problematic group including amber snails (Succineidae), which inhabit swamps and damp areas, and peculiar slugs from the South Pacific (

gray fox, (Urocyon cinereoargenteus), grizzled, gray-furred New World fox of the family Canidae. It is found in forested, rocky, and brush-covered country from Canada to northern South America. Distinguished by the reddish colour on its neck, ears, and legs, the gray fox grows to a length of about

gray fox: …related but smaller form, the island gray fox (U. littoralis), is found on islands off the coast of southern California. The name gray fox is sometimes also applied to the hoary fox (see fox) of Europe.

fungus: Annotated classification: Order Urocystales Parasitic on plants such as arrowhead, causing blister smut, and wheat, causing flag smut; mycelia may form dense clusters in leaves and leaf stalks (petioles); example genera include Urocystis, Ustacystis, and Doassansiopsis. Order Ustilaginales Parasitic on

scorpion: Annotated classification: Family Urodacidae 20 species found only in Australia. Family Chaerilidae 18 species found in southern Asia and continental Southeast Asia. Female reproductive system includes an ovariuterus, with yolk-rich ova developing within. Family Superstitioniidae 9

amphibian: Critical appraisal: …the group names Salientia and Urodela are used.

amphibian: Critical appraisal: …the group names Salientia and Urodela are used.

leaf-nosed bat: …some species, such as the tent-making bat (Uroderma bilobatum), have striped faces. American leaf-nosed bats are 4–13.5 cm (1.6–5.3 inches) without the tail, which may be absent or up to 5.5 cm (2.2 inches) long. The largest member of the family is the spectral bat (Vampyrum spectrum), sometimes called a…

reproductive system disease: In the female: …of the urogenital-tract anomalies, called urogenital cloaca, consists of congenital intercommunication between the rectum and the urinary bladder and vagina or between the rectum and the urethra and vagina.

renal system: General description: …of a membrane called the urogenital diaphragm. The urethra is narrower in this area than at any other point except at its external opening and is encircled by a muscle, the sphincter urethrae. The two small bulbourethral glands are on either side of it. The membranous urethra is not firmly…

urogenital malformation, any defect in the organs and tissues responsible for the formation and excretion of urine or in the sex organs or in both. Some of the more important conditions include: 1. Multicystic dysplastic kidney, a common type of kidney malformation in newborns in which cysts of

urogenital system, in vertebrates, the organs concerned with reproduction and urinary excretion. Although their functions are unrelated, the structures involved in excretion and reproduction are morphologically associated and often use common ducts. The major structures of the urinary system in

urography, X-ray examination of any part of the urinary tract after introduction of a radiopaque substance (often an organic iodine derivative) that casts an X-ray shadow. This contrast fluid, which passes quickly into the urine, may be taken orally or injected intravenously. It may also be

hormone: Endocrine-like glands and secretions: The urohypophysis, an organ found only in elasmobranch and bony fishes, probably developed independently in each group. The neurosecretory cells comprising the urohypophysis are concentrated at the hind end of the spinal cord, where they are associated with a vascular plexus to form a neurohemal organ.…

fibrinolytic drug: Urokinase, a protease enzyme that activates plasminogen directly, is obtained from tissue culture of human kidney cells. Urokinase lyses recently formed pulmonary emboli and, compared with streptokinase, it produces fibrinolysis without extensive breakdown of the coagulation factors.

urology, medical specialty involving the diagnosis and treatment of diseases and disorders of the urinary tract and of the male reproductive organs. (The urinary tract consists of the kidneys, the bladder, the ureters, and the urethra.) The modern specialty derives directly from the medieval

chondrichthyan: Annotated classification: Family Urolophidae (stingrays) Distinguished by having well-developed tail fin supported by cartilaginous rays; tail with at least 1 large saw-toothed spine. Ovoviviparous. The numerous species look very much alike; the largest does not exceed about 70 cm (27.5 inches) in breadth. 2 genera (Urolophus, Urotrygon) with…

chondrichthyan: Growth: The disk of the eastern Pacific round stingray (Urolophus halleri) increases in width on the average from 75 mm (3 inches) at birth to 150 mm (6 inches) when mature (that is, at 2.6 years old). In the next five years it grows about 60 mm (about 2.4 inches)…

spiny-tailed lizard, (Uromastyx), any of more than a dozen species belonging to the lizard family Agamidae. Spiny-tailed lizards live in arid and semiarid habitats from northern Africa to India. They are limbed lizards with broad heads and stout bodies, and most adults grow up to about 25 to 30 cm

Arabian Desert: Animal life: The dab (or dabb), a fat-tailed lizard, lives on the plains and reaches a length of up to three and a half feet (more than one metre). It is a vegetarian with toothless jaws, and its tail, roasted, is a Bedouin delicacy. The monitor lizard reaches lengths up…

malformation: Somatic characters: …have a single foot (uromelus), or limbs fused throughout their length with no separate feet (sirenomelus or symmelus).

malformation: Somatic characters: …have a single foot (uromelus), or limbs fused throughout their length with no separate feet (sirenomelus or symmelus).

carbohydrate: Formation of methyl ethers: …biologically, a product called a uronic acid is formed. Glycosides that are derived from d-glucuronic acid (the uronic acid formed from d-glucose) and fatty substances called steroids appear in the urine of animals as normal metabolic products; in addition, foreign toxic substances are frequently converted in the liver to glucuronides…

bat: Anatomical specializations: …their legs (the uropatagium, or interfemoral membrane). In the midline the interfemoral membrane is usually supported, at least in part, by the tail, with the distal edges often shaped in flight by greatly elongated heel bones, or calcars. The interfemoral membrane, especially well-developed in insectivorous, carnivorous, and fish-eating bats, is…

shieldtail snake, (family Uropeltidae), any of 45 species of primitive burrowing snakes endemic to southern India and Sri Lanka. There are eight genera of shieldtail snakes. Of the 30 Indian species, 18 are members of the genus Uropeltis, and of the 15 species found in Sri Lanka, 8 are members of

hake: … but placed in the genus Urophycis. These fishes resemble Merluccius but are distinguished by long, slim pelvic fins and by a small barbel at the tip of the chin. Economically important members of this genus include the white hake (U. tenuis) and the red hake (U. chuss).

hake: tenuis) and the red hake (U. chuss).

hake: …of this genus include the white hake (U. tenuis) and the red hake (U. chuss).

hormone: Endocrine-like glands and secretions: The urohypophysis, an organ found only in elasmobranch and bony fishes, probably developed independently in each group. The neurosecretory cells comprising the urohypophysis are concentrated at the hind end of the spinal cord, where they are associated with a vascular plexus to form a neurohemal organ.…

crustacean: Appendages: …others and is called the uropods. In shrimps and lobsters the uropods together with the telson form a tail fan.

metabolic disease: Porphyrias: …a deficiency of the enzyme porphobilinogen deaminase. Symptoms usually arise during adolescence, and hormonal changes (e.g., menstruation), alcohol ingestion, certain foods, and some drugs may exacerbate the condition. Diagnosis is made by detecting porphyrins in the urine. Treatment is by administration of heme during acute attacks. A high-

nightjar: The lyre-tailed nightjar (Uropsalis lyra) inhabits northwestern South America. Its outermost tail feathers may measure 60 cm (24 inches) or more, accounting for 80 to 90 percent of the bird’s total length.

mole: Mole diversity: …and American shrew moles (genera Uropsilus, Urotrichus, and Neurotrichus, respectively) differ from typical moles in that they resemble shrews and are much less specialized for burrowing. Their tails are nearly as long as the body. The external ears are large and either extend beyond the fur (Uropsilus) or are hidden…

whip scorpion, (order Uropygi, sometimes Thelyphonida), any of approximately 105 species of the arthropod class Arachnida that are similar in appearance to true scorpions except that the larger species have a whiplike telson, or tail, that serves as an organ of touch and has no stinger. The second

preen gland, in birds, an organ located on the back near the base of the tail. Paired or in two united halves, it is found in most birds. Absent in ostrich, emu, cassowary, bustard, frogmouth, and a few other birds, the oil gland is best-developed in aquatic species, notably petrels and pelicans,

Greece: Thessaly and surrounding regions: …death (1355) the self-styled emperor Symeon Uroš, despotēs of Epirus and Akarnania, was able to seize control of both Epirus and Thessaly and rule independently following the death of Nikephoros II in 1358/59. He was succeeded by his son John, who adopted the monastic life in 1373. The caesar Alexios…

oyster: The oyster drill (Urosalpinx cinenea), a widely occurring snail, drills a tiny hole through the oyster shell, then sucks out the living tissue.

uroscopy, medical examination of the urine in order to facilitate the diagnosis of a disease or disorder. Examining the urine is one of the oldest forms of diagnostic testing, extending back to the days of the ancient Greek physician Hippocrates. Physicians observed the urine to diagnose all forms

urostomy, the surgical formation of a new channel for urine and liquid wastes following the removal of the bladder or ureters. See

Istaravshan, city, Tajikistan, in the northern foothills of the Turkistan Range. One of the most ancient cities of the republic, it may date from the 6th century ce, but it bore its former name only from the 17th to the early 21st century. It was famous in the past for its handicrafts, particularly

mole: Mole diversity: …American shrew moles (genera Uropsilus, Urotrichus, and Neurotrichus, respectively) differ from typical moles in that they resemble shrews and are much less specialized for burrowing. Their tails are nearly as long as the body. The external ears are large and either extend beyond the fur (Uropsilus) or are hidden in…

Nicholas II: Early life and reign: …an extremist right-wing organization, the Union of the Russian People, which sanctioned terrorist methods and disseminated anti-Semitic propaganda. Witte, whom he blamed for the October Manifesto, was soon dismissed, and the first two Dumas were prematurely dissolved as “insubordinate.”

Canadian literature: Fiction: …the past on present lives, Jane Urquhart uses the symbol of the whirlpool to weave together stories of Canadians in 19th-century Ontario in The Whirlpool (1986); Away (1993), a lyrical saga, recounts in retrospect the life of a woman who emigrated from Ireland to Canada in the 1840s, and A…

Sir Thomas Urquhart was a Scottish author best known for his translation of the works of François Rabelais, one of the most original and vivid translations from any foreign language into English. Urquhart studied at King’s College, Aberdeen, and fought against the Covenanters at Turriff (1639). He

Alexander von Humboldt: Expedition to South America: …in the Spanish prime minister Mariano de Urquijo he found an enlightened man who supported his application to the king for a royal permit. In the summer of 1799 he set sail from Marseille accompanied by the French botanist Aimé Bonpland, whom he had met in Paris, then the liveliest…

Justo José de Urquiza was a soldier and statesman who overthrew the powerful Argentine dictator Juan Manuel de Rosas and laid the constitutional foundations of modern Argentina. A member of the Argentine oligarchy, Urquiza was educated at the College of San Carlos in Buenos Aires, from which he

El Salvador: Plant and animal life: …and the royal heron, the urraca (which has a blue breast and a gray head and is known for its call, resembling a scoffing laugh), the blue jay, and many more, some of which have fine plumage. A wide variety of fish, as well as turtles and alligators, inhabit the…

Urraca was the queen of Leon and Castile from 1109 to 1126, daughter of Alfonso VI. Urraca became her father’s heiress when her brother, Sancho, was killed at Uclés (1108). She was the widow of Count Raymond of Burgundy, by whom she had had one son, Alfonso Ramírez (born 1104), the future Alfonso

Philipp von Hutten was the last German captain general of Venezuela. A relative of the humanist poet and satirist Ulrich von Hutten, he sailed to Venezuela under Georg Hohermuth (called George of Spires) to rule on behalf of the Augsburg banking house of Welser, which had been granted a concession

alphabet: Runic and ogham alphabets: The theory of the Urrunen (forerunners of the runes), a supposed prehistoric north Germanic alphabetic script, holds that it is the parent not only of the runes but also of all the Mediterranean alphabets, including the Phoenician. This belief, based on racial and political grounds, need not be seriously…

Cuban Revolution: The fall of Batista: …provisional government was established with Manuel Urrutia Lleó as president and Castro as prime minister.

Latin American literature: Historiographies: The Cuban Ignacio José de Urrutia y Montoya, a distinguished jurist who had studied in Mexico City, left unfinished his Teatro histórico, jurídico, y político militar de la Isla Fernandina de Cuba (1789; “Historical, Legal, Political, and Military Theatre of the Island of Cuba”). The introduction manifests…