tattoo Permanent mark or design made on the body by pigment intro¬ duced through ruptures in the skin. The term is also loosely applied to the inducement of scars (cicatrization). Tattooing has been practiced in most parts of the world, and examples have been found on Egyptian and Nubian mummies dating from 2000 bc. Decoration is perhaps the most common motive, though designs may also serve to identify rank, status, or mem¬ bership and are thought by some to provide magical protection against sickness or misfortune. The word comes from Tahiti, where it was recorded by James Cook’s expedition in 1769. The first electric tattooing implement was patented in the U.S. in 1891.
Tatum \'ta-tom\, Art(hur) (b. Oct. 13, 1909, Toledo, Ohio, U.S.—d. Nov. 5, 1956, Los Angeles, Calif.) U.S. jazz pianist. Tatum was blind from birth. Influenced by Fats Waller and Earl Hines, his playing represents a synthesis of stride and swing piano traditions. He developed an unprec¬ edented technical and harmonic control on the instrument and was capable of astonishing speed and intricate elaborations of melody. By 1937 he was recognized as the outstanding pianist in jazz. He formed a trio with gui¬ tar and bass in 1943 but frequently made solo performances that show¬ cased his unique mastery.
Tatum, Edward L(awrie) (b. Dec. 14, 1909, Boulder, Colo., U.S.—d. Nov. 5, 1975, New York, N.Y., U.S.) U.S. biochemist. He worked with George Wells Beadle at Stanford University, where they con¬ firmed that all biochemical processes in organisms are ultimately con¬ trolled by genes, that these processes can be broken down into a series of individual sequential chemical reactions, each controlled by a single gene, and that mutation of a single gene changes the cell’s ability to carry out only a single chemical reaction. Each gene was found to determine the structure of a specific enzyme (the “one gene, one enzyme” hypothesis). With Joshua Lederberg, Tatum discovered the occurrence of genetic recom¬ bination, or “sex,” between certain bacteria. Largely because of their efforts, bacteria became the main source of information about genetic control of biochemical processes in the cell. Tatum, Beadle, and Leder¬ berg shared the Nobel Prize in 1958.
Taunton Town (pop., 1995 est.: 55,000), county seat of Somerset, England. An Anglo-Saxon king founded it c. 710. Its castle was besieged
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1878 I Taupo ► Tay-Sachs disease
during the English Civil Wars and subsequently dismantled. Taunton later was the scene of the duke of Monmouth’s rebellion (1685). It is in an agricultural region; tourism is also important to the economy.
Taupo \'tau-p6\, Lake Lake, North Island, New Zealand. The largest lake in New Zealand, it is 234 sq mi (606 sq km) in area and covers the remains of several volcanic craters. The Waikato River flows into and out of it. Numerous geothermal springs on the lake’s borders are used for health resorts and for generating electricity.
Taurus (Latin: “Bull”) In astronomy, the constellation lying between Aries and Gemini; in astrology, the second sign of the zodiac, governing approximately the period April 20-May 20. Its symbol is a bull, a refer¬ ence to the Greek myth in which Zeus transformed himself into a white bull to abduct Europa.
Taurus Mountains Mountain chain, southern Turkey, running paral¬ lel with the Mediterranean Sea coast. The system extends along a curve from Lake Egridir in the west to the upper reaches of the Euphrates River in the east. It has many peaks rising above 10,000-12,000 ft (3,000-3,700 m) in elevation. The Cilician Gates pass, 38 mi (61 km) long and used by caravans and armies since antiquity, crosses the range north of Tarsus.
Taussig \'tau-sig\, Helen Brooke (b. May 24, 1898, Cambridge, Mass., U.S.—d. May 20, 1986, Kennett Square, Pa.) U.S. physician. She received her medical degree from Johns Hopkins in 1927. As head of a Baltimore heart clinic (1930-63), she studied “blue babies” (babies whose heart malformations cause low blood oxygen content) and pioneered use of fluoroscopy and X rays to pinpoint the defect responsible for each set of symptoms. The surgical treatment she devised with Alfred Blalock saved thousands of such infants, and her research spurred development of other surgical treatments for heart disorders. Her Congenital Malforma¬ tions of the Heart (2 vol., 1947) comprehensively described heart defects and diagnostic tools, techniques, and findings. She also played a key role in alerting U.S. physicians to the dangers of thalidomide.
tautog See wrasse
tautology \to-'ta-b-je\ In logic, a statement that cannot be denied with¬ out inconsistency. Thus, “All bachelors are either male or not male” is held to assert, with regard to anything whatsoever that is a bachelor, that it is male or it is not male. In the propositional calculus, even complicated symbolic expressions such as [(A zd B) a (C zd —■ B)] zd (C z> —■ A) can be shown to be tautologies by displaying in a truth table every possible combination of T (true) and F (false) of its arguments A, B, C. A tautol¬ ogy can be purely formal (a statement form rather than a statement), and in some usages only such formal truths are tautologies.
tautomerism Uo-'ta-mo-.ri-zomX Existence of two or more chemical compounds that have the same chemical composition but different struc¬ tures (isomers) and that convert easily from one to another. A major class of tautomeric reactions involves exchange of a hydrogen atom between two other atoms in the same molecule, in both cases forming a covalent bond. For example, in keto-enol tautomerism, the hydrogen atom bonded to the carbon atom in a carbonyl (keto) group (—CH—C=0; see func¬ tional group) moves to the oxygen atom, making it an enol group (—C=C—OH). The keto form predominates in many aldehydes and ketones, the enol form in phenols. Sugars (e.g., glucose) exhibit tautom¬ erism between open (chain) forms and closed (ring) forms. See also isom¬ erism.
Tawney, Richard Henry (b. Nov. 30, 1880, Calcutta, India—d. Jan. 16, 1962, London, Eng.) English economic historian. He was educated at Rugby School and at the University of Oxford, where he wrote his first major work, The Agrarian Problem in the Sixteenth Century (1912). From 1913 he taught at the London School of Economics. An ardent socialist, he helped formulate the economic and moral viewpoint of the Labour Party in the 1920s and ’30s. In his most influential book, The Acquisitive Society (1920), he argued that the acquisitiveness of capitalist society was a mor¬ ally wrong motivating principle. His Religion and the Rise of Capitalism (1926), which built on the work of Max Weber, also became a classic.
tax Government levy on persons, groups, or businesses. Taxes are a gen¬ eral obligation of taxpayers and are not paid in exchange for any specific benefit. They have existed since ancient times— property TAxes and sales taxes were known in ancient Rome—but tariffs were favoured over inter¬ nal taxes as a source of revenue. In modem economies, there has been a trend away from tariffs in favour of internal taxes, which provide the
majority of revenues. Taxes have three functions: to cover government spending, to promote stable economic growth, and to lessen inequalities in the distribution of income and wealth. They have also been used for nonfiscal reasons, such as to encourage or discourage certain activities (e.g., cigarette consumption). Taxes may be classified as direct or indi¬ rect. Direct taxes are those that the taxpayer cannot shift onto someone else; they are mainly taxes on persons and are based on an individual’s ability to pay as measured by income or net wealth. Direct taxes include income TAxes, taxes on net worth, death duties (i.e., inheritance and estate taxes), and gift taxes. Indirect taxes are those that can be shifted in whole or in part to someone other than the person legally responsible for pay¬ ment. These include excise taxes, sales taxes, and value-added TAxes. Taxes may also be classified according to the effect they have on the distribu¬ tion of wealth. A proportional tax is one that imposes the same relative burden on all taxpayers, unlike progressive TAxes and regressive taxes.