Detroit City (pop., 2000: 951,270), largest in Michigan, U.S. Located on the Detroit River and founded by the French in 1701, it became a trad¬ ing centre for the Great Lakes region. It surrendered to the British during the French and Indian War, then came under U.S. control in 1796. The capital of Michigan from 1805 to 1847, it grew as one of the country’s shipping and flour-milling centres. In the 20th century it became the auto¬ mobile capital of the world with the help of Henry Ford. The city’s indus¬ trial growth attracted migrants, at first Europeans and later Southern blacks, who by 1990 made up three-fourths of the population. The decline in the area’s automotive industry brought economic hardship in the late 20th century. Wayne State University (1868) is the city’s oldest college.
Detroit River River, southeastern Michigan, U.S. Forming part of the boundary between Michigan and Ontario, Can., it connects Lake St. Clair with Lake Erie. It flows south for 32 mi (51 km) past Detroit and Wind¬ sor, Ont., where a bridge and tunnel connect the two cities. The largest islands in the river are Belle Isle (a city park of Detroit) and Grosse lie (a residential area with an airport), both in Michigan, and Fighting Island in Ontario. The river is heavily used by both pleasure craft and Great Lakes shipping.
deus ex machina Vda-os-.eks-'ma-ki-no, 'da-os-.eks-mo-'she-noN Stage device in Greek and Roman drama in which a god appeared in the sky by means of a crane (Greek, mechane ) to resolve the plot of a play. Plays by Sophocles and particularly Euripides sometimes require the device. The term now denotes something that appears suddenly and unexpectedly and provides an artificial solution to an apparently insoluble difficulty.
deuterium \du-'tir-e-9m\ or heavy hydrogen Isotope of hydrogen, chemical symbol 2 H or D, atomic number 1 (but atomic weight approxi-
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538 I deuterium oxide ► Devrient family
mately 2). Harold C. Urey won a Nobel Prize for its discovery and iso¬ lation. Its nucleus contains one proton and one neutron. A stable substance found in naturally occurring hydrogen compounds to the extent of about 0.015%, deuterium can be purified by distillation of hydrogen or by elec¬ trolysis of water. It enters into all the same chemical reactions as ordinary hydrogen; it forms D 2 and HD, analogous to molecular hydrogen (H 2 ), and D 2 0 (heavy water), analogous to ordinary water (H 2 0). Nuclear fusion of deuterium atoms or of deuterium and tritium at high temperatures releases enormous amounts of energy. Such reactions have been used in nuclear weapons and experimental power reactors. Deuterium is useful as a tracer in research into reaction mechanisms and biochemical pathways.
deuterium oxide See heavy water
Deuteronomic Reform Vdti-to-ro-'na-mikA Religious reformation in Judah during the reign of King Josiah (c. 640-609 bc). As Assyria’s hold on Israel weakened, Josiah waged a campaign against foreign cults and had their altars and idols removed from the Temple. He called for a return to the observance of Mosaic Law, based on the book of the Law discov¬ ered in the Temple of Jerusalem (c. 622 bc), believed to be the same book as the law code in the Book of Deuteronomy. Rural sanctuaries and fer¬ tility cults were destroyed and the worship of Yahweh (the God of Israel) was centralized at Jerusalem.
deva Vda-vo, 'de-vo\ (Sanskrit: “divine”) In the Vedic religion of India, one of many divine powers, roughly divided into sky, air, and earth divini¬ ties. During the Vedic period, the gods were divided into two classes, the devas and the asuras. In India the devas gradually came to be more pow¬ erful, and the asuras came to be thought of as demons. In the monothe¬ istic systems that emerged by the late Vedic period, the devas were subordinate to one supreme being.
devaluation Reduction in the exchange value of a country’s monetary unit in terms of gold, silver, or foreign currency. By decreasing the price of the home country’s exports abroad and increasing the price of imports in the home country, devaluation encourages the home country’s export sales and discourages expenditures on imports, thus improving its balance OF PAYMENTS.
devaraja N.da-vo-'ra-jaN In ancient Cambodia, the cult of the “god- king,” established early in the 9th century by Jayavarman II (c. 770-850), founder of the Khmer empire. The cult taught that the king was a mani¬ festation of the god Shiva. For centuries it provided Khmer kings with the religious basis of their royal authority.
development, biological Gradual changes in size, shape, and func¬ tion during an organism’s life that translate its genetic potentials (geno¬ type) into functioning mature systems (phenotype). It includes growth but not repetitive chemical changes (metabolism) or changes over more than one lifetime (evolution). DNA directs the development of a fertilized egg so that cells become specialized structures that carry out specific func¬ tions. In humans, development progresses through the embryo and fetus stages before birth and continues during childhood. Other mammals fol¬ low a similar course. Amphibians and insects go through distinctive stages that are quite different. In plants, the basic pattern is determined by the arrangement of lateral buds around a central growing stem. Different rates of growth of the plant’s component elements then determine its shape and that of various parts. In both animals and plants, growth is greatly influ¬ enced by hormones; factors within individual cells probably also play a role.
development bank National or regional financial institution designed to provide medium- and long-term capital for productive invest¬ ment. Such investment is usually accompanied by technical assistance. Some development banks are government-owned and -operated, while others are private. Many have been established under the auspices of the World Bank. Among the largest are the Inter-American Development Bank, the Asian Development Bank, and the African Development Bank.
developmental psychology Branch of psychology concerned with changes in cognitive, motivational, psychophysiological, and social func¬ tioning that occur throughout the human life span. In the late 19th and early 20th centuries, developmental psychologists were concerned prima¬ rily with child psychology. In the 1950s they became interested in the rela¬ tionship between child rearing and adult personality, as well as in examining adolescence in its own right. By the late 20th century they had become interested in all aspects of psychological development and change over the entire life span.
Devi \'da-ve\ Term used to designate a goddess in Hinduism. It is some¬ times used as an honorific title for women, and it may also refer to local female divinities throughout India. In the 5th-6th century, Hindu texts first began to identify Devi as the Great Goddess and the embodiment of mat¬ ter, energy, and illusion. She is represented in a variety of aspects, both good and evil, including the beautiful but menacing Durga, the destruc¬ tive Kali, and the sexually powerful Shakti (see shakti).
devil Spirit or power of evil. Though sometimes used to refer to demons, the term more often designates the prince of evil spirits. In the Bible the Devil is known as Satan, Beelzebub, and Lucifer. In Judaism, Satan emerges as subservient to God and as an adversary and accuser of Job and other humans. In postbiblical traditions he emerges as the tempter of human¬ kind and is responsible for all the sins in the Bible. Christian theology holds that his main task is to tempt humans to reject the way of life and redemption in favour of sin and death. In the Qur’an the Devil is frequently associated with IblTs; he tempts the unfaithful but not the true believer. In Hinduism there is no principal devil, although there are a variety of demons or devilish beings. Buddhists also recognize the existence of many demons, and Mara, the Buddha’s opponent and tempter, is sometimes identified as a specific devil.