appeared in 1903. In 1905 Du Bois founded the Niagara Movement, the forerunner of the NAACP. In 1910 he left teaching to become the NAACP’s director of research and editor of its magazine, Crisis (1910— 34). He returned to Atlanta University in 1934 and devoted the next 10 years to teaching and scholarship. After a second research position with the NAACP (1944-48), he moved steadily leftward politically. In 1951 he was indicted as an unregistered agent of a foreign power (the Soviet Union); though a federal judge directed his acquittal, he was by then completely disillusioned with the U.S. In 1961 he joined the Communist Party, moved to Ghana, and renounced his U.S. citizenship.
Du Buat Vdie-biE-'aV, Pierre-Louis-Georges (b. April 23,1734, Tor- tisambert, France—d. Oct. 17, 1809, Vieux-Conde) French hydraulic engineer. He compiled experimental data from which he determined his basic algebraic expression for discharge from pipes and open channels. Though valid only within the range of his experimental data, this equa¬ tion provided the best means at the time of predicting the performance of water-supply systems and similar works. His emphasis on achieving results that would be of practical use strongly influenced the development of experimental hydraulics in the 18th—19th centuries.
du Cange, Charles du Fresne, seigneur See Charles du Fresne, seigneur du Cange
Du Fu Vdti-'fiA or Tu Fu (b. 712, Xiangyang, China—d. 770, Hunan) Chinese poet, often considered the greatest of all time. After a traditional Confucian education, he failed the important civil service examinations and consequently spent much of his life wandering, repeatedly attempt¬ ing to gain court positions, with mixed success. His early poetry, which celebrates the natural world and bemoans the passage of time, garnered him renown. He suffered periods of extreme personal hardship, and as he matured his verse began to express profound compassion for humanity. An expert in all the poetic genres of his day, he is renowned for his superb classicism and skill in prosody, though many of the subtleties of his art do not survive translation.
du Maurier \du-'m6r-e-,a. Dame Daphne (b. May 13, 1907, Lon¬ don, Eng.—d. April 19, 1989, Par, Cornwall) British novelist and play¬ wright. Granddaughter of George du Maurier and daughter of the actor- manager Sir Gerald Du Maurier (1873-1934), she is best known for the romantic gothic suspense novel Rebecca (1938), one of many successful tales set on the wild coast of Cornwall. Her other novels include Jamaica Inn (1936), Frenchman’s Creek (1942), and My Cousin Rachel (1951). Her story “The Birds,” like Jamaica Inn and Rebecca , was filmed by Alfred Hitchcock.
du Maurier, George (Louis Palmella Busson) (b. March 6, 1834, Paris, France.—d. Oct. 6, 1896, London, Eng.) British caricaturist and novelist. Forced to abandon painting for drawing when he was blinded in one eye, his skilled draftsmanship and engaging personality quickly established his success. His drawings for Punch, Once a Week, and The Leisure Hour were acute commentaries on the Victorian scene. His highly successful novel Trilby (1894), about an artist’s model who falls under the spell of the musician Svengali, has entered popular mythology. His other novels were Peter Ibbetson (1891) and The Martian (1897). His granddaughter Daphne du Maurier was also a writer.
Du Mont, Allen B(alcom) (b. Jan. 29, 1901, Brooklyn, N.Y., N.Y., U.S.—d. Nov. 15, 1965, New York City) U.S. engineer. He became inter¬ ested in television in 1928, as chief engineer at the De Forest Radio Co., and concluded that television required a purely electronic system to work. In 1931 he set up what would become Allen B. Du Mont Laboratories, where he improved the cathode-ray tube and developed the modem oscil¬ loscope. In 1937 he began manufacturing the first commercial television receivers. After World War II he marketed the first widely available TV receivers and set up one of the first TV broadcasting networks. He served with the National Television System Committee formulating broadcast¬ ing standards and worked with the Federal Communications Commission in allocating frequencies for TV channels.
Dual Alliance See Austro-German Alliance, Franco-Russian Alliance dual-aspect theory See double-aspect theory Dual Monarchy See Austria-Hungary
dualism In philosophy, any pair of irreducible, mutually heterogeneous principles used to analyze the nature and origins of knowledge (episte¬ mological dualism) or to explain all of reality or some broad aspect of it
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576 I Dubayy ► Duchamp
(metaphysical dualism); also, any theory that employs dualisms. Examples of epistemological dualisms are subject and object and sensa¬ tion and sensibilia; examples of metaphysical dualisms are mind and mat¬ ter, good and evil, and God and world. Dualism is distinguished from monism and pluralism.
Dubayy or Dubai \du-'bl\ Constituent emirate (pop., 2001 est.: 913,000), United Arab Emirates (UAE). It is surrounded by the emirates of Abu Dhabi and Al-Shariqah (Sharjah), and it has 45 mi (72 km) of coastline on the Persian Gulf. Occupying an area of 1,510 sq mi (3,900 sq km), it is the second most populous and second largest state of the federation. Most of its population live in or near its capital, Dubai city (pop., 1995: 669,181). Settled in 1799 by people from Abu Dhabi, Dubayy became a locally powerful state in the early 19th century, and until the 1930s it was known for its pearl exports. It has since been enriched by petroleum exports. Dubai city is now a centre for most of the banks and insurance companies of the UAE.
Dubcek Vdiib-.chekV Alexander (b. Nov. 27, 1921, Uhrovec, Czech.—d. Nov. 7, 1992, Prague) Czech politician. In World War II he took part in the underground resistance to Nazi occupation. After the war he rose in Communist Party ranks to become a member of the Presidium of the party’s Central Committee (1962). In 1968 he forced Antonin Novotny (1904-75) to resign and replaced him as head of the Commu¬ nist Party. He introduced liberal reforms in the brief period known as the Prague Spring, which ended when the Soviet Union invaded Czechoslo¬ vakia in August 1968. Demoted to lesser posts, he was expelled from the party in 1970. He returned to prominence in 1989 after the Communist Party had given up its monopoly on power, and was elected speaker of the Czech parliament.
Dubinsky, David (b. Feb. 22, 1892, Brest-Litovsk, Russian Empire—d. Sept. 17, 1982, New York, N.Y., U.S.) U.S. labour leader. The son of a baker in Russian Poland, he was sent to Siberia in 1908 for his union activities. In 1911 he escaped and immigrated to the U.S., where he renewed his union work. In 1932 he became president of the Interna¬ tional Ladies' Garment Workers' Union (ILGWU), a post he held until 1966. As president, he transformed the ILGWU from a small, fractious regional organization into a model international union. He also played a significant role in the merger of the American Federation of Labor and the Congress of Industrial Organizations (see AFL-CIO) in 1955.
Dublin ancient Eblana City and county borough (pop., 2002 prelim.: city, 495,101; county borough, 1,122,600), capital of Ireland. On the River Liffey, it was settled by Danish Vikings arriving in the area in the 9th cen¬ tury ad; they held it until it was taken by the Irish in the 11th century. Under English control in the 12th century, it was given a charter by Henry II, establishing it as a seat of government. It prospered in the 18th cen¬ tury as a centre of the cloth trade, and its harbour dates from this period. In the 19th and 20th centuries it was the site of bloody nationalist vio¬ lence, including the 1867 Fenian movement and the 1916 Easter Rising. It is the country’s chief port, centre of finance and commerce, and seat of culture. Its Guinness Brewery is the country’s largest private employer. Educational and cultural institutions include the University of Dublin; the National Library and National Museum are housed on the grounds of Leinster House (1748), now the seat of the Irish parliament.