United Nations Security Council: History: …force known as the hybrid United Nations/African Union Mission in Darfur (UNAMID), authorized by the Security Council in July 2007. Large-scale UNAMID troop deployment did not begin until 2008, some five years after the violence began, and obstruction by the government of Sudanese Pres. Omar al-Bashir limited the mission’s effectiveness.

Roméo Dallaire: …Dallaire took command of the UN Assistance Mission for Rwanda (UNAMIR). As a lightly armed force of approximately 2,500 troops, UNAMIR was given a mandate to oversee the peace agreement ending a civil war. The death of the Rwandan president, however, whose plane was shot down over Kigali airport in…

Miguel de Unamuno was an educator, philosopher, and author whose essays had considerable influence in early 20th-century Spain. Unamuno was the son of Basque parents. After attending the Vizcayan Institute of Bilbao, he entered the University of Madrid in 1880 and in four years received a doctorate

Miguel de Unamuno was an educator, philosopher, and author whose essays had considerable influence in early 20th-century Spain. Unamuno was the son of Basque parents. After attending the Vizcayan Institute of Bilbao, he entered the University of Madrid in 1880 and in four years received a doctorate

Aleut language, one of two branches of the Eskimo-Aleut languages (Eskaleut languages). Two mutually intelligible dialects survive: Eastern Unangam Tunuu (Eastern Aleut) and Atkan Unangam Tunuu (Atkan Aleut). A third dialect, Attu Unangam Tunuu (Attu Aleut), now extinct in Alaska, survives on

Aleut, an Indigenous person of the Aleutian Islands and western portion of the Alaska Peninsula of northwestern North America. The name Aleut derives from Russian; depending upon dialect, the people refer to themselves as Unangan or Unangas (the plural of Unangax̂) and Sugpiat (the plural of

Henry Knowles Beecher was an American anesthesiologist and researcher who was an outspoken advocate of ethical standards in human-subjects research and a pioneer in the study of pain, analgesia, and clinical trials that took into account the placebo effect. He also was influential in the growth of

Unani medicine, a traditional system of healing and health maintenance observed in South Asia. The origins of Unani medicine are found in the doctrines of the ancient Greek physicians Hippocrates and Galen. As a field, it was later developed and refined through systematic experiment by the Arabs,

Unani medicine, a traditional system of healing and health maintenance observed in South Asia. The origins of Unani medicine are found in the doctrines of the ancient Greek physicians Hippocrates and Galen. As a field, it was later developed and refined through systematic experiment by the Arabs,

Unanimism, French literary movement based on the psychological concept of group consciousness and collective emotion and the need for the poet to merge with this transcendent consciousness. Founded by Jules Romains about 1908, Unanimism particularly influenced some members of the Abbaye de Créteil

Unanimism, French literary movement based on the psychological concept of group consciousness and collective emotion and the need for the poet to merge with this transcendent consciousness. Founded by Jules Romains about 1908, Unanimism particularly influenced some members of the Abbaye de Créteil

Lorna Simpson: …a series of collages titled Unanswerable (2018). The collages considered the representation of African American women by assembling photographs from vintage Jet and Ebony magazines to create absurd juxtapositions.

Charles Ives: In The Unanswered Question (composed before 1908), a string quartet or string orchestra repeats simple harmonies; placed apart from them, a trumpet reiterates a question-like theme that is dissonantly and confusedly commented upon by flutes (optionally with an oboe or a clarinet). In the second movement…

Rihanna: Later works: Rated R, Talk That Talk, and Unapologetic: …hit “We Found Love,” and Unapologetic (2012), which was anchored by the starry-eyed “Diamonds.” The latter release also controversially featured a duet with Brown, with whom she rekindled her relationship for a brief time. Her eighth studio album, Anti, was released in 2016. Rihanna began working on a new record,…

Terence Tiller: …Inward Animal (1943) and especially Unarm, Eros (1947) contain his most highly acclaimed poems, noted for their strong formal pattern, heraldic imagery, and striking sensuousness. Later volumes include Reading a Medal (1957), Notes for a Myth (1968), and That Singing Mesh (1979).

phase: Unary systems: …representation of a one-component (unary) system, in contrast to a two-component (binary), three-component (ternary), or four-component (quaternary) system. The phases coesite, low quartz, high quartz, tridymite, and cristobalite are solid phases composed of silicon dioxide; each has its own atomic arrangement and distinctive set of physical and chemical properties.…

Unas was the last king of the 5th dynasty (c. 2435–c. 2306 bce) of ancient Egypt and the first pharaoh to inscribe the interior of his pyramid at Ṣaqqārah with religious and magical texts known as Pyramid Texts. According to later king lists, Unas was the last ruler of the 5th dynasty, but the

UNASUR, South American organization created in 2008 to propel regional integration on issues including democracy, education, energy, environment, infrastructure, and security and to eliminate social inequality and exclusion. It was inspired by and modeled after the European Union. UNASUR’s members

sloth: Two-toed sloths: Both species of two-toed sloths (family Megalonychidae), also called unaus, belong to the genus Choloepus. Linnaeus’s two-toed sloth (C. didactylus) lives in northern South America east of the Andes and south to the central Amazon basin. Hoffmann’s two-toed sloth (C. hoffmanni) is

four-colour map problem: …a catalog of 1,936 “unavoidable” configurations, at least one of which must be present in any graph, no matter how large. Then they showed how each of these configurations could be reduced to a smaller one so that, if the smaller one could be coloured with four colours, so…

Saki: ” His novel The Unbearable Bassington (1912) describes the adventures of a fastidious and likable but maladjusted hero, in a manner anticipating that of the early work of the English satirist Evelyn Waugh. Munro was killed in action in World War I.

The Unbearable Lightness of Being, novel by Milan Kundera, first published in 1984 in English and French translations. In 1985 the work was released in the original Czech, but it was banned in Czechoslovakia until 1989. Through the lives of four individuals, the novel explores the philosophical

Juliette Binoche: …married to a philanderer in The Unbearable Lightness of Being, her first English-language film. Binoche’s performance was highlighted by her ability to relate a range of emotions without speaking or falling into cliché.

Nicolas Cage: …a version of himself in The Unbearable Weight of Massive Talent (2022), an action comedy that references a number of his other movies. The actor also lent his voice to such animated films as The Croods (2013), Spider-Man: Into the Spider-Verse (2018), and The Croods: A New Age (2020).

Adolf Ludwig Follen: …also the leader of the Unbedingten (Uncompromising Ones), or Schwarzen (Blacks), a radical student group whose ideas resulted in the assassination of the conservative dramatist August Kotzebue in 1819. Based on an idealized picture of the medieval Christian empire, Follen’s political ideas were aimed at incorporating the German states into…

Sigmund Freud: Religion, civilization, and discontents: …Unbehagen in der Kultur (1930; Civilization and Its Discontents), was devoted to what Rolland had dubbed the oceanic feeling. Freud described it as a sense of indissoluble oneness with the universe, which mystics in particular have celebrated as the fundamental religious experience. Its origin, Freud claimed, is nostalgia for the…

Toni Collette: …rapes in the limited series Unbelievable (2019); for her performance, she received an Emmy nomination. In Pieces of Her (2022– ), a series based on Karin Slaughter’s best-selling book, Collette played a mother with a mysterious past. Also in 2022 she starred with Colin Firth in The Staircase, a true-crime…

cosmology: Friedmann-Lemaître models: …as negatively curved spaces (“open” universes). The difference between the approaches of Friedmann and Lemaître is that the former set the cosmological constant equal to zero, whereas the latter retained the possibility that it might have a nonzero value. To simplify the discussion, only the Friedmann models are considered…

hydrocarbon: Physical properties: …number of carbon atoms, an unbranched alkane has a higher boiling point than any of its branched-chain isomers. This effect is evident upon comparing the boiling points (bp) of selected C8H18 isomers. An unbranched alkane has a more extended shape, thereby increasing the number of intermolecular attractive forces that must…

M. Night Shyamalan: Other successful films followed, including Unbreakable (2000), a superhero story about a train wreck victim (Willis) who, after suffering no injuries, realizes that he possesses special powers; Signs (2002), a science-fiction thriller about a preacher (Mel Gibson) who, after losing his faith, must contend with an alien invasion; and The…

Janet Jackson: Unbreakable (2015), billed as a comeback album, used contemporary electronic arrangements to bolster the velvety vocals that had established Jackson as an R&B star. In 2019 Jackson was inducted into the Rock and Roll Hall of Fame.

Tina Fey: …notably cocreated the Netflix series Unbreakable Kimmy Schmidt (2015–19), a comedy about a woman who moves to New York after being rescued from a doomsday cult. In 2018 she added Broadway to her credits with the premiere of the musical Mean Girls. Fey wrote the script for the stage production,…

Kentucky Derby: History: …of 92 with the colt Unbridled.

Angelina Jolie: Directing: …the World War II drama Unbroken (2014). The script for the film, based on the true story of an Olympic runner and U.S. Air Force officer who became a Japanese prisoner of war after his plane crashed, was written by the Coen brothers. In 2015 she directed, wrote, and starred…

Trinidad and Tobago: Independent Trinidad and Tobago: …the main opposition party, the United National Congress (UNC), which was supported chiefly by Indo-Trinidadians; the two Tobago seats went to the NAR, led by Robinson. The latter gave his support to the UNC, whose leader, Basdeo Panday, thus became prime minister. Panday was the first Indo-Trinidadian prime minister, and…

Battle of the Chosin Reservoir: Crossing into North Korea: …Inch’ŏn in September 1950, the United Nations Command (UNC), under the direction of U.S. Pres. Harry S. Truman’s administration and the UN General Assembly, pursued the remnants of the communist Korean People’s Army into North Korea. On the orders of Gen. Douglas MacArthur, commander of all allied forces in the…

Cameroon: Political process: …parties; it was renamed the Cameroon People’s Democratic Movement in 1985. After significant political unrest and a number of violent clashes, a constitutional amendment in 1990 established a multiparty system. Other major political parties include the National Union for Democracy and Progress, the Cameroon Democratic Union, and the Social Democratic…

uncanny valley, theorized relation between the human likeness of an object and a viewer’s affinity toward it. The hypothesis originated in a 1970 essay by Japanese roboticist Masahiro Mori, in which he proposed that as human likeness increases in an object’s design, so does one’s affinity for the

Rubiaceae: Major genera and species: …is used in tanning, from Uncaria gambir; and kratom (Mitragyna speciosa), which is used in traditional medicine and recreationally as a stimulant. Some trees in the family provide useful timber. Common madder (Rubia tinctorum) was formerly cultivated for the red dye obtained from its roots (alizarin); the roots of crosswort…

Mohegan: …a rebellion by the subchief Uncas led to Mohegan independence. After the destruction of the Pequot in 1637, most of the Pequot survivors and the former Pequot territories came under Mohegan control. Uncas strengthened his position by making an alliance with the English; by the end of King Philip’s War…

Milton, town (township), Norfolk county, eastern Massachusetts, U.S. It lies along the Neponset River, just south of Boston. Settled in 1636 as a part of Dorchester, it was early known as Uncataquisset, from an Algonquian word meaning “head of tidewater,” and was separately incorporated in 1662. At

desertification: The global reach of desertification: According to the United Nations Convention to Combat Desertification, the lives of 250 million people are affected by desertification, and as many as 135 million people may be displaced by desertification by 2045, making it one of the most severe environmental challenges facing humanity.

United Nations Capital Development Fund (UNCDF), United Nations (UN) organization established by the General Assembly in 1966 and fully operational in 1974. Headquartered in New York City, the UNDF, a semi-autonomous unit of the United Nations Development Programme, provides grants and loans to the

United Nations Conference on Environment and Development (UNCED), conference held at Rio de Janeiro, Brazil (June 3–14, 1992), to reconcile worldwide economic development with protection of the environment. The Earth Summit was the largest gathering of world leaders as of 1992, with 117 heads of

Kingsley Amis: Amis’s next novel, That Uncertain Feeling (1955), had a similar antihero. A visit to Portugal resulted in the novel I Like It Here (1958), while observations garnered from a teaching stint in the United States were expressed in the novel One Fat Englishman (1963).

Raoul Walsh: At Warner Brothers: The Roaring Twenties, High Sierra, and White Heat: Walsh and Flynn reteamed for Uncertain Glory (1944), in which a French criminal must make the supreme sacrifice to save 100 hostages held by the Nazis. Their next collaboration, Objective, Burma! (1945), was one of the decade’s best—and grittiest—war movies, with Flynn starring in one of his finest performances as…

uncertainty principle, statement, articulated (1927) by the German physicist Werner Heisenberg, that the position and the velocity of an object cannot both be measured exactly, at the same time, even in theory. The very concepts of exact position and exact velocity together, in fact, have no

Theodore Hesburgh: …Education, the Rockefeller Foundation, the United Negro College Fund, the U.S. Overseas Development Council, the U.S. Select Commission on Immigration and Refugee Policy, the International Atomic Energy Agency, the Knight Commission on Intercollegiate Athletics, and the Harvard University Board of Overseers. He received numerous awards, including the Presidential Medal of…

Mark Wahlberg: …appeared in several movies, including Uncharted, about treasure hunters.

measurement system: Greeks and Romans: 73 inch); the inch (uncia or pollicus), or 112 Roman foot, was 24.67 mm (0.97 inch); and the palm (palmus), or 14 Roman foot, was 74 mm (2.91 inches).

libra: …of the libra, the Roman uncia, is the ancestor of the English ounce.

snow leopard, large long-haired Asian cat, classified as either Panthera uncia or Uncia uncia in the family Felidae. The snow leopard inhabits the mountains of central Asia and the Indian subcontinent, ranging from an elevation of about 1,800 metres (about 6,000 feet) in the winter to about 5,500

uncial, in calligraphy, ancient majuscular book hand characterized by simple, rounded strokes. It apparently originated in the 2nd century ad when the codex form of book developed along with the growing use of parchment and vellum as writing surfaces. Unlike its prototype square roman, uncial is

hookworm disease, parasitic infestation of humans, dogs, or cats caused by bloodsucking worms living in the small intestine—sometimes associated with secondary anemia. Several species of hookworms can cause the disease. Necator americanus, which ranges in size from 5 to 11 mm (0.2 to 0.4 inch), is

bird: Skeleton: …a flat, backward-pointing spur, the uncinate process, characteristic of birds. The sternum, ribs, and their articulations form the structural basis for a bellows action, by which air is moved through the lungs. Posterior to the thoracic vertebrae is a series of 10 to 23 fused vertebrae, the synsacrum, to which…

Ascomycota: …such as those that cause powdery mildew of grape (Uncinula necator), Dutch elm disease (Ophiostoma ulmi), chestnut blight (Cryphonectria parasitica), and apple scab (Venturia inequalis).

San Francisco Conference, international meeting (April 25–June 26, 1945) that established the United Nations. The basic principles of a worldwide organization that would embrace the political objectives of the Allies had been proposed at the Dumbarton Oaks Conference in 1944 and reaffirmed at the

avunculate: …typically involves for the maternal uncle a measure of authority over his nephews (and sometimes his nieces), coupled with specific responsibilities in their upbringing, initiation, and marriage. These children, in turn, often enjoy special rights to their uncle’s property, often taking precedence in inheritance over the uncle’s children.

Apichatpong Weerasethakul: …Loong Boonmee raleuk chat (2010; Uncle Boonmee Who Can Recall His Past Lives), which won the Palme d’Or at the 2010 Cannes film festival. It tells the story of a dying man who is visited in turn by the ghost of his dead wife and that of his missing son…

John Hughes: …later appeared in the Hughes-penned Uncle Buck (1989).

Daniel Beard was an American illustrator, author, and outdoor enthusiast who was a pioneer of the youth scouting movement in the United States. Beard’s article on woodcraft appeared in the 14th edition of the Encyclopædia Britannica (see the Britannica Classic: woodcraft). Beard was the son of

Sholem Asch: …period belong Onkl Mozes (1918; Uncle Moses), Khayim Lederers tsurikkumen (1927; Chaim Lederer’s Return), and Toyt urteyl (1926; “Death Sentence”; Eng. trans. Judge Not—). These novels describe the cultural and economic conflicts experienced by eastern European Jewish immigrants in America.

Joel Chandler Harris: This and successive Uncle Remus stories won for Harris a secure place in American literature. The pattern was new: Uncle Remus, the wise, genial old black man, tells stories about Brer Rabbit, Brer Fox, and other animals to the little son of a plantation owner and interweaves his…

Georgia: Cultural life: …American trickster tales (collected as Uncle Remus: His Songs and Sayings [1880]) that have remained a vital part of American folkloric tradition.

Georgia: Cultural life: …American trickster tales (collected as Uncle Remus: His Songs and Sayings [1880]) that have remained a vital part of American folkloric tradition.

Uncle Sam, popular symbol for the United States, usually associated with a cartoon figure having long white hair and chin whiskers and dressed in a swallow-tailed coat, vest, tall hat, and striped trousers. His appearance is derived from two earlier symbolic figures in American folklore: Yankee

Uncle Tom, title character in the antislavery novel Uncle Tom’s Cabin (serialized 1851–52, published as a book in 1852) by Harriet Beecher Stowe. Initially, the character Tom—called “Uncle” Tom in the Southern fashion of showing respect for an older man—was viewed sympathetically by the novel’s

Uncle Tom’s Cabin: Criticism: The term Uncle Tom also became an insult used to describe a Black person who shows subservience to whites or is otherwise considered complicit with oppression by whites. This sense can be traced to at least the early 20th century, and early public use of it (c.…

Uncle Tom’s Cabin, novel by Harriet Beecher Stowe, published in serialized form in the United States in 1851–52 and in book form in 1852. An abolitionist novel, it achieved wide popularity, particularly among white readers in the North, by vividly dramatizing the experience of slavery. Uncle Tom’s

Uncle Tom’s Cabin, novel by Harriet Beecher Stowe, published in serialized form in the United States in 1851–52 and in book form in 1852. An abolitionist novel, it achieved wide popularity, particularly among white readers in the North, by vividly dramatizing the experience of slavery. Uncle Tom’s

Uncle Tom’s Children, collection of four novellas by Richard Wright, published in 1938. The collection, Wright’s first published book, was awarded the 1938 Story magazine prize for the best book written by anyone involved in the WPA Federal Writers’ Project. Set in the contemporary American Deep

the Jayhawks: …emerging genre’s other principal bellwether, Uncle Tupelo (forerunner of Wilco and Son Volt). Blue Earth caught the attention of producer George Drakoulias when he heard it playing in the background during a phone call with the Twin/Tone offices, which led to the band’s signing with major label Def American Recordings…

Uncle Vanya, drama in four acts by Anton Chekhov, published in 1897 as Dyadya Vanya and first produced in 1899 in Moscow. Considered one of Chekhov’s theatrical masterpieces, the play is a study of aimlessness and hopelessness. Ivan Voynitsky, called Uncle Vanya, is bitterly disappointed when he

Howard R. Garis: …American author, creator of the Uncle Wiggily series of children’s stories.

Witi Ihimaera: The Uncle’s Story (2000) relates the stories of two generations of gay Māori men. Contemporary characters are inserted into a Māori myth about warring birds in Sky Dancer (2003). The Trowenna Sea (2009), a fictionalized version of the story of a Māori man imprisoned on…

United Nations: Development of international law: …the First and the Second United Nations Conferences on the Law of the Sea (UNCLOS). The initial conference approved conventions on the continental shelf, fishing, the high seas, and territorial waters and contiguous zones, all of which were ratified by the mid-1960s. During the 1970s it came to be accepted…

desertification: Causes and consequences of desertification: In 1977, at the United Nations Conference on Desertification (UNCOD) in Nairobi, Kenya, representatives and delegates first contemplated the worldwide effects of desertification. The conference explored the causes and contributing factors and also possible local and regional solutions to the phenomenon. In addition, the delegates considered the varied consequences…

Wendy Wasserstein: Two other early works are Uncommon Women and Others (1975; revised and expanded, 1977) and Isn’t It Romantic (1981), which explore women’s attitudes toward marriage and society’s expectations of women. In The Heidi Chronicles a successful art historian discovers that her independent life choices have alienated her from men as…

San Juan Mountains: …Luis, Windom, and the highest, Uncompahgre Peak (14,309 feet [4,360 meters]). Few summits in New Mexico reach 11,000 feet (3,350 meters). Composed mainly of volcanic rocks, which are highly mineralized in the north, the mountains serve as a source for headstreams of the Rio Grande and San Juan River and…

complexity: Uncomputability: The kinds of behaviours seen in models of complex systems are the result of following a set of rules. This is because these models are embodied in computer programs, which must necessarily follow well-defined rules. By definition, any behaviour seen in such worlds is…

international trade: The most-favoured-nation clause: …clause may be conditional or unconditional. If unconditional, the clause operates automatically whenever appropriate circumstances arise. The country drawing benefit from it is not called on to make any fresh concession. By contrast, the partner invoking a conditional MFN clause must make concessions equivalent to those extended by the third…

conditioning: …its mouth is called the unconditioned response (UR) to food, which is the unconditioned stimulus (US).

conditioning: …to food, which is the unconditioned stimulus (US).

Sword of Honour, trilogy of novels by Evelyn Waugh, published originally as Men at Arms (1952), Officers and Gentlemen (1955), and Unconditional Surrender (1961; U.S. title, The End of the Battle). Waugh reworked the novels and published them collectively in one volume as Sword of Honour in 1965.

conditioning: …its mouth is called the unconditioned response (UR) to food, which is the unconditioned stimulus (US).

conditioning: …its mouth is called the unconditioned response (UR) to food, which is the unconditioned stimulus (US).

conditioning: …to food, which is the unconditioned stimulus (US).

aquifer: Types: …the water table in an unconfined aquifer system has no overlying impervious rock layer to separate it from the atmosphere.

digestive system disease: Jaundice: The first type, unconjugated, or hemolytic, jaundice, appears when the amount of bilirubin produced from hemoglobin by the destruction of red blood cells or muscle tissue (myoglobin) exceeds the normal capacity of the liver to transport it or when the ability of the liver to conjugate normal amounts…

Joseph Auslander: The Unconquerables (1943), a collection dedicated to Nazi-occupied countries, was particularly notable to the effort. Auslander also wrote novels in collaboration with his second wife, Audrey Wurdemann, the recipient of the 1935 Pulitzer Prize for poetry. Their works include My Uncle Jan (1948) and The…

Sol, in Roman religion, name of two distinct sun gods at Rome. The original Sol, or Sol Indiges, had a shrine on the Quirinal, an annual sacrifice on August 9, and another shrine, together with Luna, the moon goddess, in the Circus Maximus. Although the cult appears to have been native, the Roman

unconscious, the complex of mental activities within an individual that proceed without his awareness. Sigmund Freud, the founder of psychoanalysis, stated that such unconscious processes may affect a person’s behaviour even though he cannot report on them. Freud and his followers felt that dreams

Kazuo Ishiguro: His next novel, The Unconsoled (1995)—a radical stylistic departure from his early, conventional works that received passionately mixed reviews—focuses on lack of communication and absence of emotion as a concert pianist arrives in a European city to give a performance.

Tigris-Euphrates river system: Agriculture and irrigation: …main river in all seasons; uncontrolled canals, taking water only when the river is in flood; and raised concrete flumes, usually requiring pumps. The principal canal systems are the following: a series of left-bank Euphrates canals between Al-Ramādī and Al-Musayyib, the most important being the Al-Musayyib Drainage Project; canals derived…

natural gas: Unconventional gas reservoirs: Substantial amounts of gas have accumulated in geologic environments that differ from conventional petroleum traps. This gas is termed unconventional gas and occurs in “tight” (i.e., relatively impermeable) sandstones, in joints and fractures or absorbed into the matrix of shales, and in…

Marcia Gay Harden: In the comedy series Uncoupled (2022– ), Harden played a socialite whose husband leaves her for a much younger woman.

brown adipose tissue: …cause a protein known as thermogenin (also called uncoupling protein 1, UCP1) to become active. Thermogenin effectively uncouples electron transport in the mitochondrion from the production of chemical energy in the form of adenosine triphosphate (ATP). The resulting change in the balance of electrons and protons across the mitochondrial membrane…

unmanned aerial vehicle (UAV), military aircraft that is guided autonomously, by remote control, or both and that carries sensors, target designators, offensive ordnance, or electronic transmitters designed to interfere with or destroy enemy targets. Unencumbered by crew, life-support systems, and

Earth satellite, artificial object launched into a temporary or permanent orbit around Earth. Spacecraft of this type may be either crewed or uncrewed, the latter being the most common. The idea of an artificial satellite in orbital flight was first suggested by Sir Isaac Newton in his book

United Nations Conference on Trade and Development (UNCTAD), permanent organ of the United Nations (UN) General Assembly, established in 1964 to promote trade, investment, and development in developing countries. Headquartered in Geneva, Switzerland, UNCTAD has approximately 190 members.