Britannica Concise 2005 - читать бесплатно онлайн полную версию книги автора Encyclopedia Britannica (ч. 63)

Body plan of a generalized insect. The body is usually divided into a head, thorax, and abdomen. The head bears appendages modified into mouthparts and anten¬ nae bearing sense organs. Mouthparts include the toothed mandibles and bladelike maxillae found behind the "upper lip," or labrum. A second pair of maxillae, partly fused, form the "lower lip," or labium. An adult usually has both simple eyes (ocelli) and more-complex faceted compound eyes, as well as a pair of wings on the tho¬ rax. The tarsal segment of the jointed leg often has claws with adhesive pads, enabling the insect to hold onto smooth surfaces. In some insects (including crickets and cockroaches), a pair of feelers (cerci) bearing sense organs are located at the rear of the abdomen. Tiny openings (spiracles) on the thorax and abdomen allow passage of oxygen to and release of carbon dioxide from internal air-filled tubules or tracheae. Sperm from the male is stored in the female's spermatheca until an egg released from the ovary passes through the oviduct. The female may have an ovipositor for depositing eggs.

insecticide Any of a large group of substances used to kill insects. Such substances are mainly used to control pests that infest cultivated plants and crops or to eliminate disease-carrying insects in specific areas. Inor¬ ganic insecticides include arsenic, lead, and copper compounds. Some organic insecticides are natural, such as rotenone, pyrethrins, and nicotine (see toxin). Others are synthetic, such as chlorinated hydrocarbons (e.g., DDT, dieldrin, lindane); carbamates, related to urea (e.g., carbaryl, carbo- furan); and parathions, organic phosphorus esters. Insect hormones may be included as a class. Insecticides may affect the nervous system, inhibit essential enzymes, or prevent larvae from maturing (e.g., juvenile hor¬ mone). Some are stomach poisons, some inhalation poisons, and others contact poisons. Agents such as inert oils act mechanically, simply block¬ ing the breathing pores. Insecticides vary widely not only in effectiveness against target insects (which may develop resistance) but also in toxicity to nontarget species (including humans) and environmental effects; many of the worst (e.g., DDT) have been banned or their use curtailed.

insectivore Un-'sek-to-.voA Any member of the mammalian order (Insectivora) that includes the hedgehogs, moles, and sometimes shrews (some of which are considered primates by some authorities), or, more generally, any animal that eats mainly insects. The mammalian insecti- vores are generally small, active, and nocturnal. They are found in most parts of the world except Antarctica, Australia, and South America. Most species are solitary (except during the breeding season) and short-lived.

insei Japanese "cloistered government" Rule by retired emper¬ ors who have taken Buddhist vows and retired to cloisters. During the late 11th and the 12th century, governmental control of Japan passed from the Fujiwara family, which had maintained power through marriages to the imperial family, to cloistered emperors. By abdicating, these emperors escaped the control of Fujiwara regents and chancellors; once inside a temple or monastary, they surrounded themselves with capable non- Fujiwara aristocrats. It was the edicts of the cloistered emperor, not the

reigning one, that were obeyed, insofar as any orders were obeyed in a period of increasing collapse of central authority. The practice came to an end with the reign of the emperor Go-Daigo (1318-39). See also shoen.

inside contracting System of manufacturing intermediate between the putting-out system and full factory production. A factory proprietor sup¬ plies to an artisan who then hires the workers needed to make a particu¬ lar part under a contract with the proprietor. Inside contracting was used extensively in the U.S. in the 19th century.

Inside Passage or Inland Passage Natural sheltered sea route along the U.S.-Canadian coast from Seattle, Wash., to Skagway, Alaska. Extending northwest for more than 1,000 mi (1,600 km), it comprises channels and straits between the mainland and islands (including Van¬ couver Island) that protect it from Pacific storms. It is the favoured route for coastal shipping to Alaska. Ports in British Columbia include Victo¬ ria, Vancouver, and Prince Rupert; those in Alaska include Ketchikan, Wrangell, and Juneau.

insider trading Illegal use of insider information for profit in finan¬ cial trading. Since 1934, the Securities and Exchange Commission has pro¬ hibited trading while in possession of material nonpublic information. See also ARBITRAGE, MlCHAEL R. MlLKEN.

insolvency Condition in which liabilities exceed assets so that credi¬ tors cannot be paid. It is a financial condition that often precedes bank¬ ruptcy. In the context of equity, insolvency is the inability to pay debts as they become due; insolvency under the balance-sheet approach means that total liabilities exceed total assets.

insomnia Inability to sleep adequately. The causes may include poor sleeping conditions, circulatory or brain disorders, breathing disorders (e.g., sleep apnea), mental distress (e.g., tension or depression), or physi¬ cal discomfort. Mild insomnia may be treated by improving sleeping con¬ ditions or through traditional remedies such as warm baths, milk, or systematic relaxation. Apnea and its associated insomnia may be treated surgically or mechanically with breathing apparatus. Severe or chronic insomnia may necessitate the temporary use of barbiturates or tranquil¬ izers, but such drugs are often addictive and may be decreasingly effec¬ tive as the body builds up tolerance. Other methods of treatment include PSYCHOTHERAPY and HYPNOSIS.

instinct Involuntary response by an animal, resulting in a predictable and relatively fixed behaviour pattern. Instinctive behaviour is an inher¬ ited mechanism that serves to promote the survival of an animal or spe¬ cies. It is most apparent in fighting and sexual activity. The simplest form is the reflex. All animals have instinct, but, in general, the higher the ani¬ mal form, the more flexible the behaviour. Among mammals, learned behaviour often prevails over instinctive behaviour.

Institut Canadien \a n -ste-'tiE-ka-nad- , ya n \ Literary and scientific soci¬ ety that came into conflict with the Catholic Church in 19th-century French Canada. It was founded in Montreal in 1844 as a discussion forum and free library, and it established branches throughout French-speaking Canada. It criticized the institutionalism of the church in Quebec and dis¬ played books considered undesirable. Church leaders, including Ignace Bourget, bishop of Montreal (1840-76), attacked the institute, which appealed to Rome for support. In 1869 the church condemned the move¬ ment, and most members withdrew.

institutional economics School of economics that flourished in the U.S. in the 1920s and ’30s, which viewed the evolution of economic insti¬ tutions as part of the broader process of cultural development. Thorstein Veblen laid the foundation for institutionalism with his criticism of tradi¬ tional economic theory. He tried to replace the concept of people as the makers of economic decisions with a more realistic image of people as influenced by changing customs and institutions. John R. Commons empha¬ sized the collective action of various groups in the economy, viewed within a system of continually evolving institutions and laws. Other U.S. institu¬ tional economists include Rexford Tugwell and Wesley C. Mitchell. See also

CLASSICAL ECONOMICS, GERMAN HISTORICAL SCHOOL OF ECONOMICS.

Institutional Revolutionary Party (PRI) Political party that domi¬ nated Mexico’s political life for most of the time since its founding in 1929. It was established as a result of a shift of power from political-military chieftains to state party units following the Mexican Revolution (1910-20). Until the late 1990s, nomination to public office by the PRI virtually guar¬ anteed election, but in 1997 Mexico City elected its first non-PRI mayor. At

instrumentalism ► integral transform I 945

the national level, the president, as leader of the party, typically selected the party’s next presidential candidate—thus effectively choosing his own suc¬ cessor. Pres. Ernesto Zedillo broke from that tradition in 1999, and the fol¬ lowing year opposition candidate Vicente Fox won the presidency, although the PRI maintained control of several state governments.

instrumentalism or experimentalism Philosophy advanced by John Dewey holding that what is most important in a thing or idea is its value as an instrument of action and that the truth of an idea lies in its usefulness. Dewey favored these terms over the term pragmatism to label the philosophy on which his views of education rested. His school claimed that cognition has evolved not for speculative or metaphysical purposes but for the practical purpose of successful adjustment. Ideas are conceived as instruments for transforming the uneasiness arising from facing a prob¬ lem into the satisfaction of solving it.

instrumentation In technology, the development and use of precise measuring, analysis, and control equipment. Among the oldest known instruments of measurement was the armillary sphere, an astronomical instrument used in ancient China and Greece. The compass was a striking advance in navigational instrumentation made about the 11th century. Theodolites made accurate determination of locations possible in the 18th century. Instrumentation developed rapidly in the Industrial Revolution. Manufacturing required precision instruments, such as the screw microme¬ ter, which could measure 0.0001 in. (0.0025 mm). The industrial appli¬ cation of electricity required instruments to measure current, voltage, and resistance. Today most manufacturing processes rely on instrumentation for monitoring chemical, physical, and environmental properties. Instru¬ ments used in medicine and biomedical research are just as varied as those in industry. See also analysis.

insulator Substance that blocks or retards the flow of electric current or heat. An insulator is a poor conductor because it has a high resistance to such flow. Electrical insulators are commonly used to hold conductors in place, separating them from one another and from surrounding structures to form a barrier between energized parts of an electric circuit and con¬ fine the flow of current to wires or other conducting paths. Electrical insulators include rubber, plastic, porcelain, and mica. Thermal insulators, which break up the heat-flow path by absorbing radiant heat, include fiberglass, cork, and rock wool.

insulin Polypeptide hormone (see peptide) that regulates blood glucose levels. Secreted by the islets of Langerhans (see Langerhans, islets of) in the pancreas when blood glucose rises, as after a meal, it helps transfer the glucose into the body’s cells to be oxidized (see oxidation-reduction) for energy or converted and stored as fatty acids or glycogen. When blood glucose falls, insulin secretion stops and the liver releases more glucose into the blood. Insulin has various related functions in the liver, muscles, and other tissues, controlling the balance of glucose with related com¬ pounds. Insulin-related disorders include diabetes mellitus and hypoglycemia. Frederick Banting and J.J.R. Macleod won a Nobel Prize in 1923 for dis¬ covering insulin, and Frederick Sanger won one in 1958 for determining its amino acid sequence.

Insull Vin-solX, Samuel (b. Nov. 11, 1859, London, Eng.—d. July 19, 1938, Paris, France) British-born U.S. public-utilities magnate. He moved to the U.S. in 1881 to become the private secretary of Thomas Alva Edi¬ son and rose to become president of the Chicago Edison Co. in 1892. By 1907 he had taken control of Chicago’s transit system. By 1912 his vast electric-power system, enlarged by various mergers, was operating sev¬ eral hundred power plants. He vigorously promoted the stock of his hold¬ ing companies. When they collapsed in 1932, he fled to Europe; extradited in 1934, he was tried three times for fraud, violation of bankruptcy laws, and embezzlement but was acquitted each time.

insurance Contract that, by redistributing risk among a large number of people, reduces losses from accidents incurred by an individual. In return for a specified payment (premium), the insurer undertakes to pay the insured or his beneficiary a specified amount of money in the event that the insured suffers loss through the occurrence of an event covered by the insurance contract (policy). By pooling both the financial contributions and the risks of a large number of policyholders, the insurer is able to absorb losses much more easily than is the uninsured individual. Insurers may offer insurance to any individual able to pay, or they may contract with members of a group (e.g., employees of a firm) to offer special rates for group insurance. Marine insurance, covering ships and voyages, is the oldest form of insurance; it originated in ancient times with loans to ship¬

owners that were repayable only on safe completion of a voyage, and it was formalized in medieval Europe. Fire insurance arose in the 17th cen¬ tury, and other forms of property insurance became common with the spread of industrialization in the 19th century. It is now possible to insure almost any kind of property, including homes, businesses, motor vehicles, and goods in transit. See also casualty insurance; health insurance; liability insurance; life insurance.

intaglio \in-'tal-yo\ Engraved or incised work on gemstones, glass, ceramics, stone, or similar material in which the design is sunk beneath the surface, the opposite of cameo and relief. It is the most ancient form of gem engraving; the earliest known Babylonian cylinder seals date from c. 4000 bc. The term intaglio is also used to describe printmaking processes in which the design is cut, scratched, or etched into a printing surface of cop¬ per, zinc, or aluminum; ink is then rubbed into the incisions or grooves, the surface is wiped clean, and the paper is embossed into the incised lines with pressure from a roller press. Intaglio processes are the most versatile of printmaking methods, as they can produce a wide range of effects.

intarsia \in-'tar-se-9\ Form of wood inlay. Italian intarsia, or inlaid mosaic of wood, which probably derived from East Asian ivory and wood inlay, found its richest expression during the Renaissance in Italy (c. 1400-1600). It was often used in panels over the backs of choir stalls and in private studies and chapels of princes.

integer Whole-valued positive or negative number or 0. The integers are generated from the set of counting numbers 1, 2, 3,... and the opera¬ tion of subtraction. When a counting number is subtracted from itself, the result is zero. When a larger number is subtracted from a smaller num¬ ber, the result is a negative whole number. In this way, every integer can be derived from the counting numbers, resulting in a set of numbers closed under the operation of subtraction (see group theory).

integral Fundamental concept of calculus related to areas and other quantities modeled by functions. A definite integral gives the area between the graph of a function and the horizontal axis between vertical lines at the endpoints of an interval. It also calculates the net change in a system over an interval, thus leading to formulas for the work done by a varying force or the distance traveled by an object moving at varying speeds. When only the function is given, with no interval, it is known as an indefinite integral. The process of solving either a definite or an indefi¬ nite integral is called integration. According to the fundamental theorem of calculus, a definite integral can be calculated by using its antiderivative (a function whose rate of change, or derivative, equals the function being integrated). Integrals extend to higher dimensions through multiple inte¬ grals. See also line integral; surface integral.

integral, line See line integral integral, surface See surface integral

integral calculus Branch of calculus concerned with the theory and applications of integrals. While differential calculus focuses on rates of change, such as slopes of tangent lines and velocities, integral calculus deals with total size or value, such as lengths, areas, and volumes. The two branches are connected by the fundamental theorem of calculus, which shows how a definite integral is calculated by using its antiderivative (a function whose rate of change, or derivative, equals the function being integrated). For example, integrating a velocity function yields a distance function, which enables the distance traveled by an object over an inter¬ val of time to be calculated. As a result, much of integral calculus deals with the derivation of formulas for finding antiderivatives. The great util¬ ity of the subject emanates from its use in solving differential equations.

integral equation In mathematics, an equation with an unknown function within an integral. An example is

f(x) = | cos (xf)(p(t)dt

where f[x) is known and cp(r) is to be found, given certain conditions on /. Such equations are useful in solving differential equations.

integral transform In mathematics, a function that results when a given function is multiplied by a so-called kernel function, and the product is integrated (see integration) between suitable limits. Its value lies in its ability to simplify intractable differential equations (subject to particular

946 I integrated circuit ► intention

boundary conditions) by transforming the derivatives and boundary condi¬ tions into terms of an algebraic equation that may easily be solved. The solu¬ tion yielded must be converted to the final solution using an inverse transformation. Several integral transforms are named for the mathemati¬ cians who introduced them (Fourier transform, Laplace transform).

integrated circuit (1C) or microcircuit or chip or microchip

Assembly of microscopic electronic components (transistors, diodes, capacitors, and resistors) and their interconnections fabricated as a single unit on a wafer of semiconducting material, especially silicon. Early ICs of the late 1950s consisted of about 10 components on a chip 0.12 in. (3 mm) square. Very large-scale integration (VLSI) vastly increased circuit density, giving rise to the microprocessor. The first commercially success¬ ful IC chip (Intel, 1974) had 4,800 transistors; Intel’s Pentium (1993) had 3.2 million, and more than a billion are now achievable.

integrated pest management Technique for agricultural disease- and PEST-control in which as many pest-control methods as possible are used in an ecologically harmonious manner to keep infestation within manageable limits. Integrated pest management addresses the serious eco¬ logical problems created by the extensive use of powerful chemical pes¬ ticides. It minimizes their use and combines them with biological methods of pest control, including the breeding of pest-resistant crop varieties, the development of crop culture methods that inhibit pest proliferation, the release of predators or parasites of the pest species, and the placement of traps baited with the pest’s own sex attractants (pheromones). Chemical insecticides generally are applied only as a last resort.

Integrated Services Digital Network See ISDN

integration In calculus, the process of finding a function whose deriva¬ tive is a given function. The term, sometimes used interchangeably with “antidifferentiation,” is indicated symbolically with the integral sign J. (The differential dx usually follows to indicate x as the variable.) The basic rules of integration are: (1) j(f + g)dx = \fdx + \gdx (where/and g are functions of the variable x), (2) J kfdx = k)fdx (k is a constant), and (3)

(C is a constant). Note that any constant value may be added onto an indefinite integral without changing its derivative. Thus, the indefinite integral of 2x is x + C, where C can be any real number. A definite inte¬ gral is an indefinite integral evaluated over an interval. The result is not affected by the choice for the value of C. See also differentiation.

integument Un-'teg-yu-monA Covering of the body, which protects it from the outside world and from drying out. In humans and other mam¬ mals it consists of the skin (including outer epidermis and inner dermis) and its related structures, including hair, nails, and sebaceous and sweat glands.

Intel Corp. U.S. manufacturer of semiconductor computer circuits. Intel was founded in 1968 as NM Electronics by Robert Noyce and Gordon Moore, inventors of the integrated circuit, to manufacture large-scale inte¬ grated (LSI) circuits. In the early 1970s it introduced the most powerful semiconductor chips then known, which soon replaced the magnetic cores previously used in computer memories. IBM chose to use Intel’s 8088 microprocessor (introduced 1978) in its first personal computer (the IBM PC), and Intel microprocessors became standard for all PC-type machines. Although other manufacturers eventually developed Intel-compatible microprocessors, Intel continued to power more than 75% of PCs at the beginning of the 21st century.

intellectual property Property that derives from the work of an indi¬ vidual’s mind or intellect. Early copyright law aimed to protect the eco¬ nomic interests of book publishers rather than the intellectual rights of authors. Modem copyright law protects the labour of elaborating an idea, but not the idea itself. The concept of discovery also plays a role in intel¬ lectual property rights: a patent is awarded to one who can demonstrate that he or she has invented something not previously known. The World Trade Organization requires members to establish and enforce minimum levels of copyright, patent, and trademark protection within their jurisdic¬ tions. The World Intellectual Property Organization, which began opera¬ tions in 1970, promotes the worldwide protection of both industrial property (inventions, trademarks, and designs) and copyrighted materials (literary, musical, photographic, and other artistic works).

intelligence In education, the ability to leam or understand or to deal with new or challenging situations. In psychology, the term may more specifically denote the ability to apply knowledge to manipulate one’s environment or to think abstractly as measured by objective criteria (such as the IQ test). Intelligence is usually thought of as deriving from a com¬ bination of inherited characteristics and environmental (developmental and social) factors. The subject remains hotly debated, and many have tried to show that either biology (especially genes) or environment (espe¬ cially conditions reflecting socioeconomic class) are more or less exclu¬ sively responsible for producing differences in intelligence. Particularly contested have been studies purporting to show links between ethnic heri¬ tage and intelligence, most of which have not been accepted in the sci¬ entific community. General intelligence is often said to comprise various specific abilities (verbal ability, ability to apply logic in solving problems, etc.), but critics contend that such compartments fail to reflect the nature of cognition and that other models, perhaps based on information process¬ ing, are needed. High intelligence (as measured by tests) is sometimes shown to correlate with social achievement, but most experts believe other factors are important and that intelligence is no guarantor of success (and its lack is no guarantor of failure). See also artificial intelligence; creativity.

intelligence In government and military operations, evaluated informa¬ tion concerning the strength, activities, and probable courses of action of international actors that are usually, though not always, enemies or oppo¬ nents. The term also refers to the collection, analysis, and distribution of such information and to the secret intervention in the political or economic affairs of other countries, an activity commonly known as “covert action.” Intelligence is an important component of national power and a funda¬ mental element in decision making regarding national security, defense, and foreign policies. It is conducted on three levels: strategic, tactical, and counterintelligence. Despite the public image of intelligence operatives as cloak-and-dagger secret agents, much intelligence work involves an undramatic search of “open” sources, such as radio broadcasts and various publications. Among covert sources of intelligence are imagery intelli¬ gence, which includes aerial and space reconnaissance, signals intelli¬ gence, which includes electronic eavesdropping and code breaking, and human intelligence, which involves the secret agent working at the classic spy trade. Leading national intelligence organizations are the Central Intel¬ ligence Agency (CIA) in the U.S.; the Federal Security Service in Russia; MI5 and MI6 in Britain; and the Mossad in Israel.

intelligence quotient See IQ

intelligent design Argument intended to demonstrate that living organisms were created in more or less their present forms by an “intelli¬ gent designer.” Intelligent design was formulated in the 1990s, primarily in the United States, as an explicit refutation of the Darwinian theory of bio¬ logical evolution. Building on a version of the argument from design for the existence of God, proponents of intelligent design observed that the func¬ tional parts and systems of living organisms are “irreducibly complex” in the sense that none of their component parts can be removed without caus¬ ing the whole system to cease functioning. From this premise they inferred that no such system could have come about through the gradual alteration of functioning precursor systems by means of random mutation and natural selection, as the standard evolutionary account maintains; therefore, living organisms must have been created all at once by an intelligent designer. Proponents of intelligent design generally avoided identifying the designer with the God of Christianity or other monotheistic religions, in part because they wished the doctrine to be taught as a legitimate scientific alternative to evolution in public schools in the United States, where the government is constitutionally prohibited from promoting religion. Critics of intelligent design argued that it rests on a fundamental misunderstanding of natural selection, that it ignores the existence of precursor systems in the evolu¬ tionary history of numerous organisms, and that it is ultimately untestable and therefore not scientific. See also creationism.

intensive care unit or critical care unit Hospital facility for care of critically ill patients at a more intensive level than is needed by other patients. Staffed by specialized personnel, the intensive care unit contains a complex assortment of monitors and life-support equipment that can sustain life in once-fatal situations, including adult respiratory distress syn¬ drome, kidney failure, multiple organ failure, and sepsis (see septicemia).

intention In Scholastic logic and psychology, a concept used to describe a mode of being or relation between a mind and an object. In knowing, the mind is said to “intend” or “tend toward” its object, and a thing as

intentionality ► intermediate goods I 947

known, or in the knowing mind, has “intentional being,” as with squar¬ ing the circle, which, though impossible, can be an object of intention. In action theory, intention is taken in a different but related sense, as in act¬ ing with the intention of accomplishing a specific purpose. An important question in action theory is that of the relation between having a specific intention in doing something and doing the same thing intentionally. Is an intention necessary for intentional action and, if so, is it a cause of such action or some other kind of ground of it?

intentionality Property of being directed toward an object. Intention¬ ality is exhibited in various mental phenomena. Thus, if a person expe¬ riences an emotion toward an object, he has an intentional attitude toward it. Other examples of intentional attitudes toward an object are, looking for, believing in, and thinking about. Intentional attitudes also include propositional attitudes. One characteristic of intentionality is “inexistence”: A person may be intentionally related to an object that does not exist. Thus, what a person looks for (and intentionally seeks) may not exist, and an event he believes to occur may not occur at all. Another characteristic is referential opacity: A sentence truly ascribing an intentional state to a person may become false when some alternative description of the object of that state is substituted for it. Suppose that his pen is the millionth pen produced this year, so that “his pen” and “the millionth pen produced this year” have the same reference. It may be true to say that he is in the inten¬ tional state of searching for his pen but false to say that he is in the inten¬ tional state of searching for the millionth pen produced this year; similarly, he may believe that this is his pen and yet not believe this is the millionth pen produced this year.

interaction, fundamental See fundamental interaction

interactionism In sociology, a theoretical perspective that derives social processes (such as conflict, cooperation, identity formation) from human interaction. It was Georg Simmel who first stated that “society is merely the name for a number of individuals connected by interaction.” In the U.S., John Dewey, Charles H. Cooley, and especially George Her¬ bert Mead developed symbolic interactionism, the theory that mind and self are not part of the innate human equipment but arise through social interaction—i.e., communication with others using symbols. For symbolic interactionists, the individual is always engaged in socialization or the modification of one’s mind, role, and behaviour through contact with oth¬ ers. Other theorists, such as Alfred Schutz, drew on phenomenology to extend interactionism, an effort that led to the creation of fields such as sociolinguistics and ethnomethodology, the study of people’s sense¬ making activities. See also Erving Goffman.

interactionism In philosophy of mind, a species of mind-body dualism that holds that mind and body, though separate and distinct substances, causally interact. Interactionists assert that a mental event (as when a per¬ son forms the intention to put his hand in a fire) can be the cause of a physical action. Conversely, the physical event (his hand coming into contact with the fire) can be the cause of a mental event (his feeling an intense pain). The classical formulation of interactionism is due to Rene Descartes, who could not satisfactorily explain how the interaction takes place, apart from the speculation that it occurs in the pineal gland. This problem led some philosophers to deny that mind and body really inter¬ act and to explain appearances to the contrary by appealing to divine intervention to create mental or physical effects for physical or mental causes (see occasionalism) or to a divinely ordained “preestablished har¬ mony” between the courses of mental and physical events. Benedict de Spinoza argued for a monistic theory on which mind and body were both attributes of a single underlying substance. See also dualism; mind-body PROBLEM.

Inter-American Development Bank (IDB) international organi¬ zation founded in 1959 by 20 governments in North and South America to finance economic and social development in the Western Hemisphere. The largest charter subscribers were Argentina, Brazil, Mexico, Venezu¬ ela, and the U.S. Subscribers now include nearly 30 countries in North and South America and more than 15 countries in Europe, as well as Japan and Israel. The IDB group also includes the Inter-American Investment Corp. and the Multilateral Investment Fund. It is headquartered in Wash¬ ington, D.C.

interchangeable parts Identical components that can substitute one for another, particularly important in manufacturing. Mass production, which transformed the organization of work, came about by the develop¬ ment of the machine-tool industry by a series of 19th-century innovators.

With precision equipment, large numbers of identical parts could be pro¬ duced at low cost and with a small workforce. See also American System of manufacture; armoury practice; automobile industry; factory; Henry Ford; Henry Leland.

intercolumniation In architecture, the space between columns that support an arch or entablature. Classical, Renaissance, and Baroque archi¬ tecture used a system codified by Vitruvius in which the measurement is expressed in terms of the columns’ diameters (e.g., two columns might be described as being three diameters apart). The system conveniently expressed the measurement of a unit of space whose size varied from building to building according to the Classical order used.

intercontinental ballistic missile See ICBM

interest Price paid for the use of credit or money. It is usually figured as a percentage of the money borrowed and is computed annually. Interest is charged by the lender as payment for the loss of his or her money for a period of time. The interest rate reflects the risk of lending and is higher for loans that are considered higher-risk, a relationship known as the risk/ return tradeoff. Like the prices of goods and services, interest rates are responsive to supply and demand. Theories explaining the need for interest include the time-preference theory, according to which interest is the inducement to engage in time-consuming but more productive activities, and the liquidity-preference theory of John Maynard Keynes, according to which interest is the inducement to sacrifice a desired degree of liquidity for a nonliquid contractual obligation. Interest rates may also be used as a tool for implementing monetary policy (see discount rate). High interest rates may dampen the economy by making it difficult for consumers, businesses, and home buyers to secure loans, while lower rates tend to stimulate the economy and encourage both investment and consumption.

interference In physics, the net effect of combining two or more wave trains moving on intersecting or coincident paths. Constructive interfer¬ ence occurs if two components have the same frequency and phase; the wave amplitudes are reinforced. Destructive interference occurs when the two waves are out of phase by one-half period (see periodic motion); if the waves are of equal amplitude, they cancel each other. Two waves mov¬ ing in the same direction but having slightly different frequencies inter¬ fere constructively at regular intervals, resulting in a pulsating frequency called a beat. Two waves traveling in opposite directions but having equal frequencies interfere constructively in some places and destructively in others, resulting in a standing wave.

interferon V.in-tor-'fir-.anN Any of several related proteins produced by all vertebrates and possibly some invertebrates. They play an important role in resistance to infection. The body’s most rapidly produced and important defense against viruses, they can also combat bacteria and para¬ sites (see parasitism), inhibit cell division, and promote or impede cell dif¬ ferentiation. Interferon’s effect is indirect—it reacts with susceptible cells, which then resist virus multiplication—in contrast to antibodies, which act by combining directly with a specific virus. Various types of interferons are distinguished by their characteristics as proteins and by which cells produce them. Some are now produced by genetic engineering. Initial hopes that interferon would be a wonder drug for a wide variety of diseases were deflated by its serious side effects, but a few rare conditions respond to it.

interior design Design of interior spaces, closely related to architec¬ ture and sometimes including interior decoration. The designer’s goal is to produce a coordinated and harmonious whole in which the architec¬ ture, site, function, and visual aspects of the interior are unified, pleasing to mind and body, and appropriate to the activities to be pursued there. Design criteria include harmony of colour, texture, lighting, scale, and proportion. Furnishings must be in proportion to the space they occupy and to the needs and lifestyles of the residents. The design of such non- residential spaces as offices, hospitals, stores, and schools places clear organization of functions ahead of purely aesthetic concerns.

interleukin N.in-tor-'lii-konX Any of a class of naturally occurring pro¬ teins important in regulation of lymphocyte function. Several known types are recognized as crucial constituents of the body’s immune system (see immunity). Antigens and microbes stimulate production of interleukins, which induce production of various types of lymphocytes in a complex series of reactions that ensure a plentiful supply of T cells that fight spe¬ cific infectious agents.

intermediate goods See producer goods

948 I intermediate-range nuclear weapons ► International Court of Justice

intermediate-range nuclear weapons Class of nuclear weapons with a range of 620-3,400 mi (1,000-5,500 km). Some multiple warheads developed by the Soviet Union could strike several targets anywhere in Western Europe in less than 10 minutes. The U.S. could send a single nuclear warhead from central Europe to Moscow in less than 10 minutes. Both were regarded as offensive, first-strike weapons. U.S.-Soviet arms- control negotiations (1980-87) led to the intermediate nuclear forces (INF) treaty, signed by Mikhail Gorbachev and Ronald Reagan, to com¬ pletely remove and dismantle these and shorter-range weapons.

internal-combustion engine Any engine in which a fuel-air mix¬ ture is burned in the engine proper so that the hot gaseous products of combustion act directly on the surfaces of its moving parts, such as those of pistons (see piston and cylinder) or turbine rotor blades. Internal- combustion engines include gasoline engines, diesel engines, gas turbine engines, pure jet engines, and rocket engines and motors, and are one class of heat engines. They are commonly divided into continuous-combustion engines and intermittent-combustion engines. In the first type (e.g., jet engines) fuel and air flow steadily into the engine, where a stable flame is maintained for continuous combustion. In the second (e.g., gasoline- reciprocating-piston engines), discrete quantities of fuel and air are peri¬ odically ignited. See also automobile industry, machine, steam engine.

spark

camshaft

cam

mixture in

intake

valve

combusti

chamber

cylinder

block

valve

spring

exhaust

valve

cylinder

head

cooling

water

piston

crankcase

connecting

rod

crankshaft

Cross section showing one cylinder of a four-stroke internal-combustion engine. In the first stroke (shown), a cam (left) compresses a valve spring, opening the intake valve to admit the fuel-air mixture to the cylinder. Both valves then close, the mixture is compressed by the piston, and current is sent to the spark plug. Ignited by the spark plug, the burning mixture forces the piston down, producing power to turn the crankshaft and run the car. Another cam (right) opens the exhaust valve and the burned exhaust gases exit.

internal medicine Medical specialty dealing with the entire patient rather than a particular organ system, covering diagnosis and medical (rather than surgical) treatment in adults. Its development began in the 17th century with Thomas Sydenham’s concept of disease, but until disease- specific therapies were developed in the 20th century, internists could do little to treat diseases. As more specific treatments became available, medical knowledge increased, and subspecialties in specific organ sys¬ tems were defined, internal medicine became recognized as a specialty.

internal reflection, total See total internal reflection

Internal Revenue Service (IRS) Agency of the U.S. Department of the Treasury charged with administering and enforcing federal tax laws, except those relating to alcohol, tobacco, firearms, and explosives. It issues rulings and regulations to supplement the provisions of the Inter¬ nal Revenue Code; determines, assesses, and collects internal revenue taxes; and determines exempt organization status.

International, Communist See First International, Second Interna¬ tional, Comintern

international agreement Instrument by which nation-states and international organizations regulate matters of concern. They are governed by international law, and their purposes include the development and codification of international law, the creation of international bodies, and the resolution of actual and potential international conflict. The most com¬ prehensive agreement is a treaty; others, including conventions (e.g., the Geneva Conventions), charters (e.g., the UN charter), and pacts (e.g., the Kellogg-Briand Pact), are less formal and rely primarily on goodwill. Agreements may be negotiated between states, between an organization and a state, between organizations, or between any of those and a non¬ governmental ORGANIZATION.

International Atomic Energy Agency (IAEA) International orga¬ nization officially founded in 1957 to promote the peaceful use of nuclear energy. Based in Vienna, its activities include research on the applicabil¬ ity of nuclear energy to medicine, agriculture, water resources, and indus¬ try; provision of technical assistance; development of radiation safeguards; and public relations programs. Following the First Persian Gulf War, IAEA inspectors were called on to certify that Iraq was not manu¬ facturing nuclear weapons. The IAEA and its director general, Mohamed ElBaradei, were awarded the Nobel Prize for Peace in 2005.

International Bank for Economic Cooperation (IBEC) Inter¬ national bank instituted by an agreement signed by Bulgaria, Hungary, East Germany, Mongolia, Poland, Romania, Czechoslovakia, and the Soviet Union in 1963 to facilitate economic cooperation among member countries and promote their development. Cuba and Vietnam joined later. Its functions included making multilateral settlements in transferable rubles, advancing credit to members with temporary trade imbalances, accepting deposits in transferable rubles and in gold and convertible cur¬ rencies, and conducting arbitrage and other financial operations. After the fall of the Soviet Union it became a Russian bank with a new charter.

International Bank for Reconstruction and Development (IBRD) Main component organization of the World Bank. The IBRD lends money to middle-income and creditworthy poorer countries. Most of its funds come from sales of bonds in international capital markets. More than 180 countries are members of the IBRD. Each member’s vot¬ ing power is linked to its capital subscription; the U.S., with some one- sixth of the shares in the IBRD, has veto power over any proposed changes to the bank. See also International Monetary Fund; United Nations Devel¬ opment Programme.

International Brigades Groups of foreign volunteers who fought on the Republican side against the Nationalist forces in the Spanish Civil War (1936-39). So-called because their members initially came from some 50 countries, the International Brigades were recruited, organized, and directed by the Comintern, with headquarters in Paris. The U.S. con¬ tingent called itself the Abraham Lincoln Batallion. Many of the mostly young recruits were commu¬ nists before they became involved in the conflict; more joined the party during the course of the war. The total number of volunteers reached about 60,000. The brigades were for¬ mally withdrawn from Spain late in

International Court of Justice (ICJ) or World Court Principal judicial body of the United Nations, located at The Hague. Its predeces¬ sor organization was the Permanent Court of International Justice, the judicial body of the League of Nations. Its first session was held in 1946. Its jurisdiction is limited to disputes between states willing to accept its authority on matters of international law. Its decisions are binding, but it has no enforcement power; appeals must be made to the UN Security

"The Internationals—United with the Spaniards We Fight the Invader," poster by Parrilla, published by the International Brigades, 1936-37.

COURTESY OF THE ABRAHAM LINCOLN BRIGADE ARCHIVES, BRANDEIS UNIVERSITY LIBRARY

International Criminal Court ► International Refugee Organization I 949

Council. Its 15-member body of judges, each of whom serves a nine-year term, is elected by countries party to the court’s founding statute. No two judges may come from the same country. See also European Court of Jus¬ tice.

International Criminal Court (ICC) Permanent judicial body estab¬ lished by the Rome Statute of the International Criminal Court (1998) to prosecute individuals accused of genocide, war crimes, and crimes against humanity. The court commenced operations on July 1, 2002, after the requisite number of countries (60) ratified the Rome Statute (some 140 countries signed the agreement). The ICC was established as a court of last resort to prosecute the most heinous offenses in cases where national courts fail to act. It is headquartered in The Hague. By 2002 China, Rus¬ sia, and the U.S. had declined to participate in the ICC, and the U.S. had campaigned actively to have its citizens exempted from the court’s juris¬ diction.

International Date Line Imaginary line from the North Pole to the South Pole that arbitrarily separates each calendar day from the next. It corresponds along most of its length to the 180th meridian of longitude but deviates to the east through the Bering Strait to avoid dividing Sibe¬ ria and then deviates to the west to include the Aleutian Islands with Alaska. South of the Equator, another eastward deviation allows certain island groups to have the same day as New Zealand. The date line is a consequence of the worldwide use of timekeeping systems arranged so that local noon corresponds approximately to the time at which the Sun crosses the local meridian of longitude. See also standard time.

international exchange See foreign exchange International Harvester Co. See Navistar International Corp.

International Herald Tribune Daily newspaper published in Paris. It has long been the staple source of English-language news for Ameri¬ can expatriates, tourists, and businesspeople in Europe. Its roots are in the Paris Herald (established 1887); a merger in 1924 between its parent, the New York Herald , and the New York Tribune created the New York Herald- Tribune and the Paris Herald Tribune. The Paris edition, which was far¬ ing well at the time of its parent’s demise in 1966, was renamed when it was rescued by a joint venture of the New York Times, the Washington Post, and Whitney Communications. The New York Times Co. and the Washington Post Co. became half-owners of the paper in 1991. The New York Times Co. became the full owner in 2003.

International Labour Organization (ILO) Specialized agency of the United Nations system dedicated to improving labour conditions and living standards throughout the world. Established in 1919 through the Treaty of Versailles as an agency of the League of Nations, the ILO became the first specialized agency affiliated with the UN in 1946. Its activities include compiling labour statistics, protecting international migrants, and safeguarding trade-union rights. Its delegates come from member gov¬ ernments (50%), labour (25%), and employers (25%). About 175 coun¬ tries are represented in the ILO. It received the Nobel Prize for Peace in

International Ladies' Garment Workers' Union (ILGWU)

Former industrial union in the U.S. and Canada that represented workers in the women’s clothing industry. When it was formed in 1900, most of its members were Jewish immigrants working in sweatshops. Successful ILGWU strikes in New York in 1909-10 secured higher wages and shorter hours. Under the leadership of David Dubinsky (president 1932-66), the union grew from 45,000 members to almost half a million. Active in the effort to organize mass-production industries, it was expelled from the AFL in 1937 but returned in 1940. From the 1970s, membership shrank as U.S. firms moved garment production overseas, and in 1995 the ILGWU merged with the Amalgamated Clothing and Textile Workers’ Union to form the Union of Needletrades, Industrial and Textile Employ¬ ees. See also AFL-CIO.

international law Body of legal rules, norms, and standards that apply between sovereign states and other entities that are legally recog¬ nized as international actors. The term was coined by the English phi¬ losopher Jeremy Bentham. Important elements of international law include sovereignty, recognition (which allows a country to honour the claims of another), consent (which allows for modifications in international agree¬ ments to fit the customs of a country), freedom of the high seas, self- defense (which ensures that measures may be taken against illegal acts committed against a sovereign country), freedom of commerce, and pro¬

tection of nationals abroad. International courts, such as the International Court of Justice, resolve disputes on these and other matters, including war crimes. See also asylum; immunity.

International Monetary Fund (IMF) Specialized agency of the United Nations system. It was conceived at the Bretton Woods Conference (1944) and officially founded in 1945 as a voluntary cooperative institu¬ tion to help ensure the smooth international buying and selling of cur¬ rency. More than 180 countries are members of the IMF. Its principal functions are stabilizing currency-exchange rates, financing the short-term balance-of-payments deficits of member countries, and providing advice and technical assistance to borrowing countries. Members contribute operating funds and receive voting rights according to their volume of international trade, national income, and international reserve holdings; the U.S. holds in excess of one-sixth of the voting rights, more than twice the percentage of any other member. The IMF has no coercive power over members, but it can refuse to lend money to members that do not agree to adhere to its policies; as a last resort it can ask members to withdraw from the organization. Critics of the IMF contend that the austerity and privatization measures it requires of borrowing countries reduce economic growth, deepen and prolong financial crises, and create severe hardships for the world’s poorest people. See also International Bank for Recon¬ struction and Development; World Bank.

international organization Institution drawing membership from at least three states, having activities in several states, and whose mem¬ bers are held together by a formal agreement. Only a few existed before 1850; several thousand were active in the early 21st century. Some are intergovernmental (e.g., the United Nations), and some are nongovern¬ mental (e.g., Amnesty International). Some have multiple worldwide or regional purposes (e.g., the European Union), and some have single pur¬ poses (e.g., the World Intellectual Property Organization). One effect of their proliferation is a stronger sense of interdependence among states, which in turn has stimulated recognition of the need for cooperation to address international and global problems.

International Organization for Standardization (ISO) Orga¬ nization for determining standards in most technical and nontechnical fields. Founded in Geneva in 1947, its membership includes more than 100 countries. An appropriate national body represents each country; for example, the U.S. member is the American National Standards Institute (ANSI). Standardization affects units of measurement, alphabetization and transliteration, and specifications for parts, materials, surfaces, pro¬ cesses, tools, methods of testing, and machines. The ISO publishes the results of its work as “International Standards” (IS). ISO standards are optimally reviewed every five years.

international payment Payment made between countries, whether in settlement of a trade debt, as a unilateral transfer of funds, for capital investment, or for some other purpose. The reasons for such payments and the methods of making them and accounting for them are matters of concern to economists and national governments. International debts are settled either from accumulated balances of foreign currency or claims on foreign currency, or by loans from creditor to debtor, or by drawing on the International Monetary Fund, or by movements of gold. How a coun¬ try balances its international accounts is one of the most important deci¬ sions for its BALANCE OF PAYMENTS.

International Phonetic Alphabet (IPA) Set of symbols intended as a universal system for transcribing speech sounds. The promulgation and updating of the IPA has been a principal aim of the International Pho¬ netic Association (Association Phonetique Internationale), founded in Paris in 1886. The first IPA chart was published in 1888. IPA symbols are based on an extended version of the Latin alphabet, with modifications of some letters and the use of additional symbols, some of which had been used in earlier phonetic alphabets. Diacritics are used primarily to show various kinds of secondary articulation.

International Refugee Organization (IRO) Temporary special¬ ized agency of the United Nations system (1946-52). The IRO assisted refugees and displaced persons in Europe and Asia who could not or would not return home after World War II. Taking over the work of its principal predecessor, the United Nations Relief and Rehabilitation Adminis¬ tration, it also assumed responsibility for the legal protection and resettle¬ ment of refugees previously carried out by the Intergovernmental Committee on Refugees. It was succeeded by the Office of the United Nations High Commissioner for Refugees.

950 I international relations ► Internet

international relations Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political parties). It is related to a number of other academic disciplines, including political science, geography, history, eco¬ nomics, law, sociology, psychology, and philosophy. The field emerged at the beginning of the 20th century largely in the West and particularly in the U.S. as that country grew in power and influence. The study of inter¬ national relations has always been heavily influenced by normative con¬ siderations, such as the goal of reducing armed conflict and increasing international cooperation. At the beginning of the 21st century, research focused on issues such as terrorism, religious and ethnic conflict, the emer¬ gence of substate and nonstate entities, the spread of weapons of mass destruction and efforts to counter nuclear proliferation, and the develop¬ ment of international institutions.

International Space Station (ISS) Space station assembled from modules in Earth orbit largely by the U.S. and Russia, with assistance and components from a multinational consortium. The project, which began as a U.S. effort, was long delayed by funding and technical problems. Originally called Freedom in the 1980s, it was redesigned in the 1990s to reduce costs and expand international involvement, at which time it was renamed. In-orbit construction started in late 1998 with the launches of a Russian control module and a U.S.-built connecting node, which were linked in orbit by space shuttle astronauts. In mid 2000 a habitat and control-centre module was added, and later in the year the ISS received its first resident crew, comprising two Russians and an American. Other elements were subsequently joined to the station, with the overall plan calling for a complex of laboratories and habitats crossed by a long truss supporting four large solar power arrays. Station construction involved at least 16 countries, including Canada, Japan, Brazil, and 11 members of the European Space Agency. Much of the early work aboard the ISS would focus on long-term life-sciences and material-sciences research in the weightless environment. It was expected to serve as the basis for human operations in Earth orbit for at least the first quarter of the 21st century.

International Standard Book Number (ISBN) Ten-digit num¬ ber assigned before publication to a book or edition thereof. The ISBN identifies various elements of the work, grouping it within a national, geographic, language, or other convenient category and revealing its pub¬ lisher, title, edition, and volume number. The ISBN is part of the Inter¬ national Standard Bibliographic Description (ISBD), which was prescribed by the International Organization for Standardization; del¬ egates adopted the numbering system in 1969. The numbers are assigned by publishers and administered by designated national standard book numbering agencies such as the R.R. Bowker Co. in the U.S. and the Standard Book Numbering Agency Ltd. in Britain.

International Style Architectural style that developed in Europe and the U.S. in the 1920s and ’30s and dominated Western architecture in the mid 20th century. The term was first used in 1932 by Henry-Russell Hitchcock and Philip Johnson in their essay “The International Style: Architecture Since 1922.” The style’s most common characteristics are rectilinear forms, open interior spaces, large expanses of glass, steel, and reinforced-concrete construction, and light, taut plane surfaces devoid of

Savoye House, Poissy, Fr., an International Style residence by Le Corbusier,

1929-30

PIERRE BELZEAUX—RAPHO/PHOTO RESEARCHERS

applied ornamentation. Walter Gropius, Ludwig Mies van der Rohe, and Le Corbusier are among the architects most clearly associated with the style. See also Bauhaus.

International System of Units or Systeme International d'Unites \ses- , tem-a n -ter-na-sy6- , nal-dCe-ne- , ta\ or SI system Interna¬ tional decimal system of weights and measures derived from and extend¬ ing the metric system of units. Adopted by the 11th General Conference on Weights and Measures in 1960, it was developed to eliminate overlapping but different systems of units of measures fostered by rapid advances in science and technology in the 19th-20th centuries. Its fundamental units include the metre (m) for length, the kilogram (kg) for mass, and the sec¬ ond (sec) for time. Derived units include those for force (newton, N), energy (joule, J), and power (watt, W). See table on opposite page.

International Telecommunication Union (ITU) United Nations agency headquartered in Geneva. Its roots can be traced to 1865, when the International Telegraph Union was established to coordinate interna¬ tional development of the telegraph. It acquired its present name in 1934 and became a UN specialized agency in 1947. Its activities include regu¬ lating allocation of radio frequencies, setting standards on technical and operational matters, and assisting countries in developing their own tele¬ communications systems.

International Telephone and Telegraph Corp. (ITT) Former U.S. telecommunications company. It was founded in 1920 by Sosthenes and Hemand Behn as a holding company for their Caribbean-based tele¬ phone and telegraph companies. It expanded into the European market and became a major telecommunications manufacturer. In the 1960s and ’70s ITT became a conglomerate, acquiring firms including the Sheraton Corp. and the Hartford Fire Insurance Co. It divested its telecommunica¬ tions businesses in 1987, and in 1995 it split into three companies: ITT Hartford Group Inc. (insurance); ITT Industries Inc. (defense electronics and auto parts); and a “new” ITT Corp., which merged with Starwood Lodgings in 1997.

international unit Any of several precision standards used in mea¬ suring physical quantities, such as mass, length, and time (see Interna¬ tional System of Units), and also lighting systems, radiation processes, and pharmacology. The luminous intensity or candlepower of a light is expressed in candelas. The second is based on the frequency of radiation emitted by cesium-133 atoms. In radioactive decay, the international unit is the number of disintegrations per second in a sample. In pharmacol¬ ogy, the international unit is the quantity of a substance (vitamin, hor¬ mone, or toxin) that produces a specified effect when tested according to an internationally accepted procedure.

International Whaling Commission (IWC) An intergovernmen¬ tal organization created in 1946 to control the rapid escalation of whal¬ ing. The original purpose of the IWC was to preserve whale stocks for commercial whalers. Whale populations, however, continued to decline, and in 1986 the IWC instituted a moratorium on commercial whaling that remains in effect. At the beginning of the 21st century, 40 countries belonged to the commission, but membership has fluctuated over the years. The commission’s success has been limited by governments leav¬ ing the IWC, ignoring its policies, or breaching regulations.

Internet Publicly accessible computer network connecting many smaller networks from around the world. It grew out of a U.S. Defense Department program called ARPANET (Advanced Research Projects Agency Net¬ work), established in 1969 with connections between computers at the Uni¬ versity of California at Los Angeles, Stanford Research Institute, the University of California-Santa Barbara, and the University of Utah. ARPA¬ NET’S purpose was to conduct research into computer networking in order to provide a secure and survivable communications system in case of war. As the network quickly expanded, academics and researchers in other fields began to use it as well. In 1971 the first program for sending e-mail over a distributed network was developed; by 1973, the year international connections to ARPANET were made (from Britain and Norway), e-mail represented most of the traffic on ARPANET. The 1970s also saw the devel¬ opment of mailing lists, newsgroups and bulletin-board systems, and the TCP/IP communications protocols, which were adopted as standard pro¬ tocols for ARPANET in 1982-83, leading to the widespread use of the term Internet. In 1984 the domain name addressing system was introduced. In 1986 the National Science Foundation established the NSFNET, a distrib¬ uted network of networks capable of handling far greater traffic, and within a year more than 10,000 hosts were connected to the Internet. In 1988 real-

Internet Protocol address ► Interpol I 951

International System of Units*

(Basic Units)

LENGTH

Unit

Abbreviation

Number of Meters

Approximate U.S. Equivalent

kilometer

1,000

0.62 mile

hectometer

100

328.08 feet

deka meter

dam

32.81 feet

meter

39.37 inches

decimeter

0.1

3.94 inches

centimeter

0.01

0.39 inch

millimeter

0.001

0.039 inch

micrometer

|jm

0.000001

0.000039 inch

AREA

Unit

Abbreviation

Number of Square Meters

Approximate U.S. Equivalent

square kilometer

sq km or km 2

1,000,000

0.3861 square miles

hectare

10,000

2.47 acres

are

100

119.60 square yards

square centimeter

sq cm or cm 2

0.0001

0.155 square inch

VOLUME

Unit

Abbreviation

Number of Cubic Meters

Approximate U.S. Equivalent

cubic meter

m 3

1.307 cubic yards

cubic decimeter

dm 3

0.001

61.023 cubic inches

cubic centimeter

cu cm or cm 3 also cc

0.000001

0.061 cubic inch

CAPACITY

Unit

Abbreviation

Number of Liters

Approximate U.S. Equivalent

cubic dry liquid

kiloliter

1,000

1.31 cubic yards

hectoliter

100

3.53 cubic feet 2.84 bushels

dekaliter

dal

0.35 cubic foot 1.14 pecks 2.64 gallons

liter

61.02 cubic inches 0.908 quart 1.057 quarts

cubic decimeter

dm 3

61.02 cubic inches 0.908 quart 1.057 quarts

deciliter

0.10

6.1 cubic inches 0.18 pint 0.21 pint

centiliter

0.01

0.61 cubic inch 0.338 fluid ounce

milliliter

0.001

0.061 cubic inch 0.27 fluid dram

microliter

0.000001

0.000061 cubic inch 0.00027 fluid dram

MASS AND WEIGHT

Unit

Abbreviation

Number of Grams

Approximate U.S. Equivalent

metric ton

1,000,000

1.102 short tons

kilogram

k 9

1,000

2.2046 pounds

hectogram

h 9

100

3.527 ounces

dekagram

dag

0.353 ounce

gram

0.035 ounce

decigram

d g

0.10

1.543 grains

centigram

c 9

0.01

0.154 grain

milligram

0.001

0.015 grain

microgram

0.000001

0.000015 grain

*For metric equivalents of U.S. units, see Weights and Measurements table

time conversation over the network became possible with the development of Internet Relay Chat protocols (see chat). In 1990 ARPANET ceased to exist, leaving behind the NSFNET, and the first commercial dial-up access to the Internet became available. In 1991 the World Wide Web was released to the public (via FTP). The Mosaic browser was released in 1993, and its popularity led to the proliferation of World Wide Web sites and users. In 1995 the NSFNET reverted to the role of a research network, leaving Inter¬ net traffic to be routed through network providers rather than NSF super¬ computers. That year the Web became the most popular part of the Internet, surpassing the FTP protocols in traffic volume. By 1997 there were more than 10 million hosts on the Internet and more than 1 million registered domain names. Internet access can now be gained via radio signals, cable- television lines, satellites, and fibre-optic connections, though most traffic still uses a part of the public telecommunications (telephone) network. The Internet is widely regarded as a development of vast significance that will affect nearly every aspect of human culture and commerce in ways still only dimly discernible.

Internet Protocol address See IP address

Internet service provider (ISP) Company that provides Internet connections and services to individuals and organizations. For a monthly fee, ISPs provide computer users with a connection to their site (see data transmission), as well as a log-in name and password. They may also pro¬ vide software packages (such as browsers), e-mail accounts, and a personal Web site or home page. ISPs can host Web sites for businesses and can also build the Web sites themselves. ISPs are all connected to each other through network access points, public network facilities on the Internet backbone.

Interpol officially International Criminal Police Organiza¬ tion International organization whose purpose is to fight international crime. Interpol promotes the widest possible mutual assistance between the criminal police authorities of affiliated countries and seeks to estab¬ lish and develop all institutions likely to contribute effectively to the pre¬ vention and suppression of ordinary crime. The organization traces its

952 I interpolation ► intonation

history to 1914, when a congress of international criminal police, attended by delegates from 14 countries, was held in Monaco. Interpol was for¬ mally founded in Austria in 1923 with 20 member countries; after World War II its headquarters moved to Paris and, in 1989, to Lyon, France. By the early 21st century, its membership exceeded 180 countries. Interpol pursues criminals who operate in more than one country (e.g., smugglers), those who stay in one country but whose crimes affect other countries (e.g., counterfeiters of foreign currency), and those who commit a crime in one country and flee to another.

interpolation In mathematics, estimation of a value between two known data points. A simple example is calculating the mean (see mean, median, and mode) of two population counts made 10 years apart to estimate the population in the fifth year. Estimating outside the data points (e.g., pre¬ dicting the population five years after the second population count) is called extrapolation. If more than two data points are available, a curve may fit the data better than a line. The simplest curve that fits is a poly¬ nomial curve. Exactly one polynomial of any given degree—an interpo¬ lating polynomial—passes through any number of data points.

interrogation In criminal law, process of formally and systematically questioning a suspect in order to elicit incriminating responses. The pro¬ cess is largely outside the governance of law, though in the U.S. relatively elaborate safeguards have been placed on police interrogatory powers in order to protect the rights of the accused.

interstate commerce In the U.S., any commercial transaction or traf¬ fic that crosses state boundaries or that involves more than one state. Gov¬ ernment regulation of interstate commerce is founded on the commerce clause of the Constitution (Article I, section 8), which authorizes Congress “To regulate Commerce with foreign Nations, and among the several States, and with Indian Tribes.” The Interstate Commerce Commission, estab¬ lished in 1887, was originally intended to regulate the railroad industry; its jurisdiction was later expanded to include trucks, ships, freight forwarders, and other interstate carriers. The Sherman Act (1890), followed by the Clayton Act (1914), made illegal any act that tended to interfere with free competition between and among industries, businesses, and any interstate commercial venture. The Federal Trade Commission (FTC) was estab¬ lished by the Federal Trade Commission Act of 1914, which gave the FTC powers—judicial, legislative, and executive—to administer the Sherman and Clayton acts. The Federal Communications Commission (FCC) was created to protect the right of the public to the airwaves through licensing and oversight of the practices of broadcasters in radio and television. In the 20th century, court decisions tended to interpret interstate commerce broadly, thus allowing Congress to regulate a wide variety of activities by which interstate commerce could be affected, even if they took place within the borders of a single state. One such decision was Heart of Atlanta Motel v. U.S. (1964), in which the Supreme Court upheld the prohibition of dis¬ crimination in public accommodations contained in the 1964 Civil Rights Act on the ground that the discriminatory practices of a business operating in only one state could affect interstate commerce.

Interstate Commerce Commission (ICC) (1887-1995) First regu¬ latory agency established in the U.S. and a prototype for independent government regulatory bodies. An agency of the U.S. Department of Transportation, it was responsible for the economic regulation of inter¬ state surface transportation, including railroads, trucking companies, and buslines. It certified carriers, regulated rates, oversaw mergers, and approved railroad construction. The ICC was dissolved in 1995.

interstellar medium Content of the region between the stars, includ¬ ing vast, diffuse clouds of gases and minute solid particles. Such tenuous matter in the Milky Way Galaxy accounts for about 5% of its total mass. By no means a complete vacuum, the interstellar medium contains mainly hydrogen gas, with a smaller amount of helium and sizable quantities of dust particles of uncertain composition. Primary cosmic rays also travel through interstellar space, and magnetic fields extend across much of it. Most interstellar matter occurs in cloudlike concentrations, which can condense to form stars. Stars, in turn, continually lose mass through stel¬ lar winds (see solar wind). Supernovas and planetary NEBULAe also feed mass back to the interstellar medium, where it mixes with matter that has not yet formed stars (see Populations I and II).

interval In music, the inclusive distance between one tone and another, whether sounded successively (melodic interval) or simultaneously (har¬ monic interval). In Western music, intervals are generally named accord¬ ing to the number of scale-steps within a given key that they embrace;

thus, the ascent from C to G (C-D-E-F-G) is called a fifth because the interval embraces five scale degrees. There are four perfect intervals: prime, or unison; octave; fourth; and fifth. The other intervals (seconds, thirds, sixths, sevenths) have major and minor forms that differ in size by a half step (semitone). Both perfect and major intervals may be aug¬ mented, or enlarged by a half tone. Perfect and minor intervals may be diminished, or narrowed by a half tone.

oo A-° -e-” ^ -o-^ ^ -o-

unison | third | fifth | seventh |

second fourth sixth octave

Examples of simple musical intervals.

intestate succession In the law of inheritance, transmission of prop¬ erty or property interests of a decedent as provided by statute, as distin¬ guished from transfer according to the decedent’s will. Modern laws of intestacy, though they vary widely, share the common principle that the estate should devolve upon persons standing in some kinship relation with the decedent; modern practice tends to favour the rights of the surviving spouse.

intestinal gas Volatile material (mostly swallowed air, partly digestive by-products) in the digestive tract, which normally contains 150-500 cc of gas. Air in the stomach is either belched out or passed to the intestines. Some of its oxygen is absorbed into the blood along the way. Carbon dioxide produced by digestion is added. Nitrogen, the major component, is inert and usually passed on. Obstructions in the small intestine can trap gas in distended pockets, causing severe pain. In the large intestine, bac¬ terial fermentation products are added—mostly hydrogen but also meth¬ ane, hydrogen sulfide, ammonia, and sulfur-containing mercaptans. Excess gas in the colon is eventually expelled from the body.

intestinal obstruction Blockage of the small intestine or large intes¬ tine, resulting from either lack of peristalsis or mechanical obstruction (e.g., by narrowing, foreign objects, or HERNIA). Obstruction near the start of the small intestine often causes vomiting. Near the end or in the large intes¬ tine, backed-up waste and swallowed air cause intestinal distention; the resulting pressure may cause necrosis (death of intestinal wall tissue). Waste products may escape into the bloodstream. Symptoms and treat¬ ment depend on the obstruction’s nature and location.

intestine See large intestine, small intestine

intifadah \,in-ti-'fa-d3\ Arabic "shaking off" Palestinian revolt (1987-93, 2000- ) against the Israeli occupation in the Gaza Strip and West Bank. Initially a spontaneous reaction to 20 years of occupation and worsening economic conditions, it was soon taken over by the Palestine Liberation Organization (PLO). Its tactics included strikes, boycotts, and confrontations with Israeli troops. The International Red Cross estimated that some 800 Palestinians, more than 200 under the age of 16, had been killed by Israeli security forces by 1990. Several dozen Israelis were killed during the same period. Intifadah pressure is credited with helping make possible the 1993 Israeli-PLO agreement on Palestinian self-rule. A break¬ down in further negotiations in late 2000 led to another outburst of vio¬ lence, which quickly became known as the Aqsa intifadah, named for the Aqsa Mosque in Jerusalem, where the fighting began. See also Yasir 'Arafat; Fatah; Hamas.

Intolerable Acts or Coercive Acts (1774) Four punitive measures enacted by the British Parliament against the American colonies. Boston’s harbour was closed until restitution was made for the tea destroyed in the Boston Tea Party; the Massachusetts colony’s charter was annulled and a military governor installed; British officials charged with capital offenses could go to England for trial; and arrangement for housing British troops in American houses was revived. The Quebec Act added to these oppres¬ sive measures. The acts, called “intolerable” by the colonists, led to a convening of the Continental Congress.

intonation In phonetics, the melodic pattern of an utterance. Intonation is primarily a matter of variation in the pitch level of the voice (see tone), but in languages such as English, stress and rhythm are also involved. Intonation conveys differences of expressive meaning (e.g., surprise.

introvert and extravert ► investment bank I 953

doubtfulness). In many languages, including English, intonation serves a grammatical function, distinguishing one type of phrase or sentence from another. Thus, “it’s gone” is an assertion when spoken with a drop in pitch at the end, but a question when spoken with a rise in pitch at the end.

introvert and extravert Basic personality types, according to the theories of Carl Gustav Jung. The introvert, who directs thoughts and feelings inward, is often shy, contemplative, and reserved. The extravert, who directs attention toward other people and the outside world, is usu¬ ally outgoing, responsive, and aggressive. This typology is now regarded as simplistic because almost no one can be described as wholly introverted or extraverted.

intrusive rock Igneous rock formed from magma forced into older rocks at depths within the Earth’s crust, which then slowly solidifies below the Earth’s surface, though it may later be exposed by erosion. Igneous intru¬ sions form a variety of rock types. See also extrusive rock.

intuition In philosophy, the power of obtaining knowledge that is not or cannot be acquired either by inference or observation. As such, intu¬ ition is thought of as an original, independent source of knowledge, since it is designed to account for just those kinds of knowledge that other sources do not provide. Knowledge of some necessary truths and basic moral principles is sometimes explained in this way. A technical sense of intuition, deriving from Immanuel Kant, refers to immediate acquaintance with individual entities; intuition ( Anschauung ) in this sense may be empirical (e.g., consciousness of sense-data) or pure (e.g., consciousness of space and time a priori as forms of all empirical intuitions). As con¬ ceived by Benedict de Spinoza and Henri Bergson, intuition is taken to be concrete knowledge of the world as an interconnected whole, as con¬ trasted with the piecemeal, “abstract” knowledge obtained by science and observation.

intuitionism School of mathematical thought introduced by the Dutch mathematician Luitzen Egbertus Jan Brouwer (1881-1966). In contrast with mathematical Platonism, which holds that mathematical concepts exist independent of any human realization of them, intuitionism holds that only those mathematical concepts that can be demonstrated, or con¬ structed, following a finite number of steps are legitimate. Few mathema¬ ticians have been willing to abandon the vast realms of mathematics built with nonconstructive proofs.

intuitionism In metaethics, a form of cognitivism that holds that moral statements can be known to be true or false immediately through a kind of rational intuition. In the 17th and 18th centuries, intuitionism was defended by Ralph Cudworth, Henry More (1614-87), Samuel Clarke (1675-1729), and Richard Price (1723-91); in the 20th century its sup¬ porters included H.A Prichard (1871-1947), G.E. Moore, and David Ross. Intuitionists have differed over the kinds of moral truths that are ame¬ nable to direct apprehension. For example, whereas Moore thought that it is self-evident that certain things are morally valuable, Ross thought that we know immediately that it is our duty to do acts of a certain type.

Inuit See Eskimo

Invar Trademark name for an alloy of iron (64% iron, 36% nickel) that expands very little when heated. Invar was formerly used for absolute standards of length measurement and is now used for surveying tapes and in watches and various other temperature-sensitive devices. The name expresses the invariability of its dimensions. It was developed by Charles- Edouard Guillaume (1861-1938), winner of the 1920 Nobel Prize for Physics.

inventory In business, any item of property held in stock by a firm, including finished goods held for sale, goods in the process of production, raw materials, and items that will be consumed in the process of produc¬ ing salable goods. Inventories appear on a company’s balance sheet as assets. Inventory turnover, which indicates the rate at which goods are converted into cash, is a key factor in appraising a firm’s financial con¬ dition. For financial statements, inventories may be priced either at cost or at market value.

Inverness \,in-v9r-'nes\ Royal burgh (pop., 2001: 44,084), Highland council area, in the historic county of Inverness-shire, northwestern Scot¬ land. Located on the River Ness and the Caledonian Canal, it has long been the centre of the Scottish Highlands. In the 6th century it was the capital of the Pictish king Brude. By the 12th century it had become a burgh near the castle of Malcolm III Canmore. Inverness is now an edu¬

cational and tourist centre. Its manufacturing has expanded in conjunc¬ tion with the growth of offshore oil production.

inverse function Mathematical function that undoes the effect of another function. For example, the inverse function of the formula that converts Celsius temperature to Fahrenheit temperature is the formula that converts Fahrenheit to Celsius. Applying one formula and then the other yields the original temperature. Inverse procedures are essential to solv¬ ing equations because they allow mathematical operations to be reversed (e.g. logarithms, the inverses of exponential functions, are used to solve exponential equations). Whenever a mathematical procedure is intro¬ duced, one of the most important questions is how to invert it. Thus, for example, the trigonometric functions gave rise to the inverse trigonomet¬ ric functions.

invertebrate Any animal that lacks a vertebral column, or backbone. They include the protozoans, annelids, cnidarians, echinoderms, flatworms, nematodes, mollusks, and arthropods. More than 90% of living animals are invertebrates. Worldwide in distribution, they range in size from minute protozoans to giant squids. Apart from the absence of a vertebral column, invertebrates have little in common. They are generally soft-bodied and have an external skeleton for muscle attachment and protection. See also VERTEBRATE.

Investiture Controversy Struggle between the papacy and the secu¬ lar rulers of Europe over the latter’s presentation of the symbols of office to churchmen. Pope Gregory VII condemned lay investiture in 1078 as an unjustified assertion of secular authority over the church; the issue was pivotal in his dispute with King Henry IV and in the larger struggle over Henry’s refusal to obey papal commands. Henry successfully drove Gre¬ gory from Rome and installed an antipope, but it would be Gregory’s rejection of lay investiture that would ultimately prevail. Henry I of England renounced lay investiture (1106) in return for the guarantee that homage would be paid to the king before consecration, and the Concor¬ dat of Worms (1122) forged a similar compromise between Henry V and Calixtus II.

investment Process of exchanging income for an asset that is expected to produce earnings at a later time. An investor refrains from consumption in the present in hopes of a greater return in the future. Investment may be influenced by rates of interest, with the rate of investment rising as interest rates fall, but other factors more difficult to measure may also be important—for example, the business community’s expectations about future demand and profit, technical changes in production methods, and expected relative costs of labour and capital. Investment cannot occur without saving, which provides funding. Because investment increases an economy’s capacity to produce, it is a factor contributing to economic growth.

investment bank Firm that originates, underwrites, and distributes new security issues of corporations and government agencies. The Banking

954 I investment casting ► Ionian

Act of 1933 required the separation of investment banking and commercial BANKing functions. Investment banks operate by purchasing all the new securities issued by a corporation at one price and selling fractions of the new issue to the investing public at prices high enough to yield a profit. The investment bank is responsible for setting the public offering price, which it bases on probable demand and assessments of the economic climate. A syndicate of investment banking firms underwrites and distributes most security issues in order to divide the risk of the new issue. An initial public offering (IPO) refers to the issuance of the first public shares of a formerly nonpublic company. See also bank; central bank; savings bank; security.

investment casting Precision casting for forming metal shapes with minutely precise details. Casting bronze or precious metals typically involves several steps, including forming a mold around the sculptured form; detaching the mold (in two or more sections); coating its inside with wax; forming a second mold, of heat-resisting clay, around the wax shell, and filling the interior with a clay core; baking the assembly (hardening the clay and melting the wax, which escapes through openings in the outer mold); pouring molten bronze into the space vacated by the wax; and breaking the mold to expose the cast form. In modern foundries, plastics, or occasionally frozen mercury, are used instead of wax. See also lost- wax CASTING, DIE CASTING.

investment credit or investment tax credit Tax incentive that permits companies or individuals to deduct a specified percentage of cer¬ tain investment costs from their tax liability in addition to the normal allowances for depreciation. Investment credits are similar to investment allowances, which permit investors or businesses to deduct a specified percentage of certain capital costs from taxable income. Both investment credits and investment allowances differ from accelerated depreciation by offering a percentage deduction at the time an asset is purchased. In effect, the credits are subsidies for investment. Investment credits and investment allowances were adopted by the U.S. in 1962 in order to protect domes¬ tic business from foreign competition but have since been applied toward the support of energy conservation, pollution control, or various forms of desirable economic development.

investment trust or closed-end trust Financial organization that pools the funds of its shareholders and invests them in a diversified port¬ folio of securities. It differs from a mutual fund, which issues units repre¬ senting diversified holdings rather than shares in the company itself. Investment trusts have a fixed number of shares for sale; their price depends on the market value of the underlying securities and on the demand for and supply of shares. The first modern investment trusts were formed in England and Scotland as early as 1860. Many early U.S. invest¬ ment trusts failed with the collapse of the stock market in 1929, but oth¬ ers have since prospered under stricter federal regulation.

lo \'I-o\ In Greek mythology, the daughter of the river god Argos. Io drew Hera’s jealousy when Zeus fell in love with her. Zeus changed her into a white heifer to protect her. Hera sent the many-eyed creature Argus to watch over the heifer, but Zeus sent Hermes to lull Argus to sleep and kill him. Hera then sent a gadfly to pursue Io, who fled across Europe and crossed the bodies of water later named the Ionian Sea and the Bosporus (“Ford of the Cow”) in her honour. When she arrived in Egypt she resumed her original form. She was later identified with the Egyptian goddess Isis.

iodine Nonmetallic chemical element, chemical symbol I, atomic num¬ ber 53. The heaviest nonradioactive halogen, it is a nearly black crystal¬ line solid (diatomic molecule I 2 ) that sublimes (see sublimation) to a deep violet, irritating vapour. It is never found in nature uncombined. Its sources (mostly in brines and seaweeds) and compounds are usually iodides; iodates (small amounts in saltpeter) and periodates also occur. Dietary iodine is essential for thyroid gland function; in areas of the world where food contains insufficient iodine, an iodine compound such as potassium iodide (KI) is added to table salt (sodium chloride) to prevent iodine deficiency. Elemental iodine is used in medicine, in synthesizing some organic chemicals, in manufacturing dyes, in analytical chemistry (see analysis) to measure fat saturation (see hydrogenation) and to detect starch, and in photography. The radioactive isotope iodine-131 (see radio¬ activity), with an eight-day half-life, is very useful in medicine (see nuclear medicine) and other applications.

iodine deficiency Inadequate intake or metabolism of iodine. It directly affects thyroid secretions, which influence heart action, nerve response, growth rate, and metabolism. Simple goitre, the most frequent result, is most common in areas without access to salt water and is rare

along seacoasts. Severe, prolonged deficiency can cause hypothyroidism. Eating seafood regularly or using iodized table salt will prevent iodine deficiency. Some countries have made dietary iodine additives mandatory.

ion Atom or group of atoms with one or more positive or negative elec¬ tric charges. Positively charged ions are cations, negatively charged ones anions. Ions are formed when electrons are added to or removed from neutral molecules or other ions, as sodium (Na) and chlorine (Cl) atoms react to form Na + and Cl - ; when ions combine with other particles, as hydrogen cations (H + ) and ammonia (NH 3 ) combine to form ammonium cations (NH 4 + ); or when a covalent bond between two atoms is ruptured in such a way that the resulting particles are charged, as water (H 2 0) dis¬ sociates (see dissociation) into hydrogen and hydroxide ions (H + and OH - ). Many crystalline substances (see crystal) are composed of ions held in regular geometric patterns by the attraction of oppositely charged par¬ ticles for each other. Ions migrate to the electrode of opposite charge in an electric field and are the conductors of current in electrolytic cells (see electrolysis). Compounds that form ions are called electrolytes. Ions are also formed in gases when heated to very high temperatures or when an electrical discharge passes through them (see plasma).

ion-exchange resin Any of a wide variety of synthetic polymers con¬ taining positively or negatively charged sites that can interact with or bind to an ion of opposite charge from a surrounding solution. Light, porous solids in granules, beads, or sheets, they absorb the solution and swell as they attract the target ions; when exhausted, they are removed from use and regenerated by an inexpensive brine or carbonate solution. A solid support of styrene-divinylbenzene copolymer to which are attached sul¬ fonic or carboxylic acid groups is often used to attract and exchange cat¬ ions (e.g., ions of hydrogen or metals). Quaternary ammonium groups on the solid matrix are used to attract anions (e.g., ions of chlorine). Indus¬ trially, the resins are used to soften hard water, purify sugar, and concen¬ trate valuable elements (gold, silver, uranium) from their ores. In the laboratory they are used to separate and concentrate substances and some¬ times as catalysts. Zeolites are minerals with ion-exchange properties.

Ionesco \yo-nes-'ko\ / Eugene orig. Eugen lonescu (b. Nov. 26, 1909, Slatina, Rom.—d. March 28,

1994, Paris, France) Romanian-born French playwright. He studied in Bucharest and Paris, where he lived from 1945. His first one-act “anti¬ play,” The Bald Soprano (1950), inspired a revolution in dramatic techniques and helped inaugurate the Theatre of the Absurd. He followed it with other one-act plays in which illogical events create an atmosphere both comic and grotesque, including The Lesson (1951), The Chairs (1952), and The New Tenant (1955).

His most popular full-length play,

Rhinoceros (1959), concerns a pro¬ vincial French town in which all the citizens are metamorphosing into rhinoceroses. Other plays include Eugene Ionesco, 1959.

Exit the King (1962) and A Stroll in markgerson the Air (1963). He was elected to the Academie Fran§aise in 1970.

Ionia M-'o-nyoV Ancient region, western coast of Asia Minor (modem Turkey) bordering the Aegean Sea. It consisted of a coastal strip that extended from the mouth of the Hermus River to the Halicarnassus Pen¬ insula, a distance of 100 mi (160 km). In the 8th century bc there were 12 major Greek cities in the region, including Phocaea, Erythrae, Colophon, and Miletus on the mainland, and the islands Chios and Samos. It was very prosperous, and until 500 bc Ionic philosophy and architecture and the Ionic dialect were highly influential in Greece. In the mid-6th century bc it fell to Lydia and then to the Persians. After a brief period of independence beginning in 334 bc, it became part of the Seleucid kingdom. In 133 bc it passed to the Romans and became part of the Roman province of Asia. It was devastated during the Turkish conquest of Asia Minor.

Ionian Any ancient Greek inhabitant of Ionia, from the time of the col¬ lapse of Mycenae. Ionian cities colonized southern Italy and opened up the Black Sea from c. 700 bc. Their contributions to Greek culture

Ionian ► IQ I 955

included the epics of Homer and the earliest elegiac and iambic poetry. They began the study of geography, philosophy, and historiography in the 6th century. After Alexander the Great their literary language was the basis of Koine, or “common speech,” the language of practically all Greek writ¬ ing to the present day.

Ionian \I-'o-ne-3n\ Islands ancient Heptanesos Group of seven Greek islands (pop., 2001: 214,274) in the Ionian Sea. They include Corfu, Cephalonia, Zacynthus, Leucas, Ithaca, Cythera, and Paxos and have a combined land area of 891 sq mi (2,307 sq km). Controlled by Venice in the 15th and 16th centuries, they were taken by Russian and Turkish forces in 1799. In 1815 the Treaty of Paris placed them under the control of Britain; the British ceded them to Greece in 1864.

Ionian revolt Uprising (499-494 bc) of some of the Ionian cities of Asia Minor against their Persian overlords. The cities deposed their own tyrants and, with help from Athens, tried unsuccessfully to throw off Per¬ sian domination. Darius I of Persia used Athens’s involvement as a pre¬ text for his invasion of Greece in 490, initiating the Persian Wars, which resulted in a stronger Athenian influence in western Anatolia.

Ionian school School of Greek philosophers of the 6th-5th century bc, including Thales, Anaximander, Anaximenes, Heracleitus, Anaxagoras, Dio¬ genes of Apollonia, Archelaus, and Hippon. Though Ionia was the origi¬ nal center of their activity, they differed so greatly from one another in their conclusions that they cannot truly be said to represent a specific school of philosophy, but their common concern to explain phenomena in terms of matter or physical forces distinguished them from later think¬ ers.

Ionian Sea Part of the Mediterranean Sea lying between Greece, Sic¬ ily, and Italy. Though once considered part of the Adriatic Sea, to which it connects by the Strait of Otranto, it is now considered a separate body. The Mediterranean reaches its greatest depth (16,000 ft or 4,900 m) in the Ionian south of Greece. Along its eastern shore are the Ionian Islands.

ionic bond Electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when one or more electrons are transferred from one neutral atom (typically a metal, which becomes a cation) to another (typically a nonmetallic element or group, which becomes an anion). The two types of ion are held together by electrostatic forces in a solid that does not comprise neutral molecules as such; rather, each ion has neighbours of the opposite charge in an ordered overall crys¬ talline structure. When, for example, crystals of common salt (sodium chloride, NaCl) are dissolved in water, they dissociate (see dissociation) into two kinds of ions in equal numbers, sodium cations (Na + ) and chlo¬ ride anions (Cl - ). See also bonding; covalent bond.

ionization Process by which electrically neutral atoms or molecules are converted to electrically charged atoms or molecules (ions) by the removal or addition of negatively charged electrons. It is one of the principal ways in which radiation transfers energy to matter, and hence of detecting radia¬ tion. In general, ionization occurs whenever sufficiently energetic charged particles or radiant energy travels through gases, liquids, or solids. A cer¬ tain minimal level of ionization is present in the earth’s atmosphere because of continuous absorption of cosmic rays from space and ultravio¬ let radiation from the sun.

ionization potential or ionization energy Amount of energy required to remove an electron from an isolated atom or molecule. There is an ionization potential for each successive electron removed, though that associated with removing the first (most loosely held) electron is most commonly used. The ionization potential of an element is a measure of its ability to enter into chemical reactions requiring ion formation or dona¬ tion of electrons and is related to the nature of the chemical bonding in the compounds formed by elements. See also binding energy, ionization.

ionosphere M-'an-a-.sfirX Region of the Earth’s atmosphere in which the number of ions, or electrically charged particles, is large enough to affect the propagation of radio waves. The ionosphere begins at an alti¬ tude of about 30 mi (50 km) but is most distinct above about 50 mi (80 km). The ionization is caused mainly by solar radiation at X-ray and ultra¬ violet wavelengths. The ionosphere is responsible for the long-distance propagation, by reflection, of radio signals in the shortwave and broad¬ cast bands.

Iowa State (pop., 2000: 2,926,324), midwestem U.S. Bordered by Min¬ nesota, Wisconsin, Illinois, Missouri, Nebraska, and South Dakota, it cov¬

ers 56,276 sq mi (145,755 sq km). Its capital is Des Moines. The Des Moines River flows across the state from northwest to southeast. The Mis¬ sissippi River forms its eastern boundary, while the Missouri River and the Big Sioux River define portions of its western boundary. The Sauk, Fox, Iowa, and Sioux Indians lived in the region when French explorers Louis Jolliet and Jacques Marquette arrived in 1673. The U.S. acquired Iowa as part of the Louisiana Purchase in 1803. Following the Black Hawk War and purchase of eastern Iowa from the Sauk and Fox Indians in the 1830s, white settlement advanced rapidly. Iowa became a territory in 1838 and was made the 29th state in 1846. After the Civil War, railroad expansion drew large waves of immigrants from the east and from Europe. After World War I population growth slowed. Its economy is based on agricul¬ ture, and Iowa is a leader in the U.S. production of livestock.

IP address in full Internet Protocol address Number that uniquely identifies each computer on the Internet. A computer’s IP address may be permanently assigned or supplied each time that it connects to the Internet by an Internet service provider. In order to accommodate the extraordinary growth in the number of devices connected to the Internet, a 32-bit protocol standard, known as IPv4, began to be replaced by a 128- bit protocol, IPv6, in 2000. See also TCP/IP; domain name; URL.

ipecac \'i-pi-,kak\ or ipecacuanha \,i-pi- I ka-kyo- , wa-n3\ Dried rhi¬ zome and roots of either of two tropical New World plants ( Cephaelis acuminata and C. ipecacuanha ) of the madder family. It has been used since ancient times especially as a source of a drug to treat poisoning by induc¬ ing nausea and vomiting. The name also refers to the drug itself.

Iphigeneia U-fo-jo-'nI-oX In Greek mythology, the eldest daughter of Agamemnon and Clytemnestra and sister of Electra and Orestes. When the Achaean fleet was becalmed at Aulis, Iphigeneia’s father sacrificed her to Artemis in order to secure favourable winds to carry the ships to Troy. Her mother later avenged her death by murdering Agamemnon. Iphigeneia’s story is treated in plays by Aeschylus, Sophocles, and Euripides. According to Euripides, she did not die but was saved by Artemis; she went to the land of Tauris, where she became a priestess, and she saved Orestes from madness and death when he fled there after killing their mother.

Ipoh \'e-po\ City (pop., 2000 prelim.: 566,211), western Malaysia. Its name comes from a local tree, whose poisonous resin was once used by indigenous people for hunting. The modern city dates from the 1890s, when British tin-mining companies were set up. Immigrant Chinese were brought in to work the tin deposits, and their descendants now dominate the city. It is the country’s mining capital.

Ipsus, Battle of (301 bc) Battle marking the defeat at Ipsus, Phrygia, of Antigonus I Monophthalmus and his son Demetrius I Poliorcetes at the hands of Lysimachus of Thrace, Seleucus I Nicator of Babylon, Ptolemy I Soter of Egypt, and Cassander of Macedonia. Antigonus was killed and his Asian territory lost, but Demetrius kept territory in Greece and Mace¬ donia. The battle was part of the struggle for control of territories that made up Alexander the Great’s empire.

Ipswich Town and borough (pop., 2001: 117,074), administrative and historic county seat of Suffolk, England. Located northeast of London, it was chartered in 1200. It prospered as a port for the export of East Anglian textiles from medieval times to the 17th century. It is now an agricultural market and service centre. Its landmarks include the 16th-century Christchurch mansion and the Great White Horse coaching inn mentioned in Charles Dickens’s The Pickwick Papers. It was the birthplace of Tho¬ mas Cardinal Wolsey.

IQ in full intelligence quotient Number intended to represent a mea¬ sure of relative intelligence as determined by the subject’s responses to a series of test problems. The IQ was originally computed as the ratio of a person’s mental age to his or her chronological (physical) age, multiplied by 100, but use of the concept of mental age has been largely discontin¬ ued, and IQ is now generally assessed on the basis of the statistical dis¬ tribution of scores. The most widely used intelligence tests are the Stanford-Binet test (1916), for children, and the Wechsler test (1939), originally for adults but now also for children. A score above 130 is con¬ sidered to reflect “giftedness,” while a score below 70 is considered to reflect mental impairment or mental retardation. Intelligence tests have provoked great controversy, particularly about what kinds of mental abil¬ ity constitute intelligence and whether IQ adequately represents these abilities, and about cultural and class bias in test construction and stan¬ dardization procedures.

956 I Iqaluit ► Iranian languages

Iqaluit \e-'ka-lu-it\ formerly Frobisher Bay Town (pop., 2001: 5,236), capital of Nunavut territory, Canada. Situated on southeastern Baffin Island, it is the largest community in the eastern Canadian Arctic. It was established as a trading post in 1914 and became an air base dur¬ ing World War II. It later was the site of construction camps for the DEW (Distant Early Warning) line of radar stations. It is the site of a meteo¬ rological station and a hospital. It became Nunavut’s capital in 1999.

Iqbal Vik-,bal\, Sir Muhammad (b. Nov. 9, 1877, Si)lkot, Punjab, India—d. April 21, 1938, Lahore, Punjab, Pakistan) Indian poet and phi¬ losopher. He first won fame for his poetry, which was written in the clas¬ sical style for public recitation and became known even among the illiterate. His perspective grew increasingly Pan-Islamic, as revealed in the long poem The Secrets of the Self ( 1915), which he wrote in Persian in order to address a broader Muslim audience. Calling for a revitaliza¬ tion of Islam, he advocated the separate Muslim state that would even¬ tually be realized with the founding of Pakistan in 1947, and he was acclaimed after his death as the father of that country. His poetic master¬ piece is “The Song of Eternity” (1932). He is considered the greatest 20th-century poet to write in Urdu.

iqta* \ik-'ta\ Type of land tenure system practiced in early Islamic soci¬ eties. Under the iqta ( system, which began in the 9th century, political leaders awarded the right of usufruct over land to an individual (usually in exchange for military service) for a limited period. It differed from feu¬ dal land tenure practiced in Europe by the fact that land in the Islamic system remained the property of the original owner, not the recipient or granter of the iqta\ The exact implementation of the system varied from region to region and changed over time.

IRA See Irish Republican Army

Iran officially Islamic Republic of Iran formerly Persia Country, Middle East, southwestern Asia. Area: 636,374 sq mi (1,648,200 sq km). Population (2005 est.): 69,515,000. Capital: Tehran. Persians constitute

OMAN Gulf of Oman

about one-third of its population; other eth¬ nic groups include Azerbaijanians, Kurds, Lurs, Bakhtyari, and Balochi. Languages: Persian (Farsi; official), numerous others.

Religions: Islam (official; predominantly Shfite); also Zoroastrianism. Currency: rial. Iran occupies a high plateau, rising higher than 1,500 ft (460 m) above sea level, and is surrounded largely by mountains. More than half of its surface area consists of salt deserts and other wasteland. About one-tenth of its land is arable, and another one-fourth is suitable for grazing. Iran’s rich petroleum reserves account for about one-tenth of world reserves and are the basis of its economy. It is an Islamic republic with one legislative house and several

oversight bodies dominated by clergy. The head of state and government is the president, but supreme authority rests with the rahbar, a ranking cleric. Human habitation in Iran dates to some 100,000 years ago, but recorded history began with the Elamites c. 3000 bc. The Medes flour¬ ished from c. 728 but were overthrown in 550 by the Persians, who were in turn conquered by Alexander the Great in the 4th century bc. The Parthians (see Parthia) created an empire that lasted from 247 bc to ad 226, when control passed to the Sasanian dynasty. Various Muslim dynas¬ ties ruled from the 7th century. In 1501 the Safavid dynasty was estab¬ lished and lasted until 1736. The Qajar dynasty ruled from 1796, but in the 19th century the country was economically controlled by the Russian and British empires. Reza Khan (see Reza Shah Pahlavi) seized power in a coup (1921). His son Mohammad Reza Shah Pahlavi alienated religious leaders with a program of modernization and Westernization and was overthrown in 1979; ShTite cleric Ruhollah Khomeini then set up an Islamic republic, and Western influence was suppressed. The destructive Iran-Iraq War of the 1980s ended in a stalemate. Since the 1990s the government has gradually moved to a more liberal conduct of state affairs.

Iran-Contra Affair U.S. political scandal. In 1985 Robert McFarlane, head of the National Security Council (NSC), authorized sales of weap¬ ons to Iran in an attempt to secure the release of U.S. hostages held in Lebanon by pro-Iranian terrorist groups. The deal contravened stated policy regarding both dealings with terrorists and military aid to Iran. At the instigation of Oliver North, a NSC staff member, and with the approval of John M. Poindexter, part of the $48 million paid by Iran for the arms was diverted to the Nicaraguan contras, in direct violation of a 1984 law banning such assistance. A Senate investigation resulted in the conviction of North and Poindexter on charges of obstructing justice and related offenses, though their convictions were later overturned on the ground that testimony given at their trials had been influenced by information they had supplied to Congress under a limited grant of immunity. Pres. Ronald Reagan accepted responsibility for the arms-for-hostages deal but denied any knowledge of the diversion.

Iran hostage crisis (1979-81) Political crisis involving Iran’s deten¬ tion of U.S. diplomats. Anti-American sentiment in Iran—fueled in part by close ties between the U.S. and the unpopular leader Mohammad Reza Shah Pahlavi —peaked when Pahlavi fled Iran during the 1979 Iranian revolution. When the monarch entered the U.S. for medical treatment later that year, Islamic militants stormed the U.S. embassy in Tehran and seized 66 Americans. The hostage-takers, who enjoyed the tacit support of the new Iranian regime of Ruhollah Khomeini, demanded the shah’s extradi¬ tion to Iran, but Pres. Jimmy Carter refused and froze all Iranian assets in the U.S. The Iranians released 13 women and African Americans on Nov. 19-20, 1979, and another hostage was released in July 1980. A rescue attempt in April 1980 failed. Negotiations for the hostages’ return began after the shah died in July 1980, but the remaining 52 hostages were kept in captivity until Jan. 20, 1981, when they were released moments after the inauguration of Ronald Reagan. The crisis contributed to Carter’s fail¬ ure to win reelection. See also Iran-Contra Affair.

Iran-Iraq War (1980-90) Protracted and indecisive conflict prompted by Iraq’s invasion of its eastern neighbour. Following the 1979 Iranian revolution, the Iraqi leadership sought to exploit Iran’s military and politi¬ cal chaos in order to resolve border disputes, gain control of Iran’s oil- rich western (largely Arab) province, and achieve hegemony in the Persian Gulf. Iraq was successful early (1980-82) but began to lose ground and sought to negotiate peace. Iran refused, and the war turned into a bloody stalemate that included the first use of chemical warfare since World War I (1914-18). After additional Iraqi advances, Iran agreed to a cease-fire in 1988. Peace was concluded only when Iraq invaded another neighbour, Kuwait, in 1990. See also Saddam Hussein; Ruhollah Khomeini.

Iranian languages Major subgroup of the Indo-Iranian branch of the Indo-European language family. Iranian languages are probably spoken by more than 80 million people in southwestern and southern Asia. Only two Old Iranian languages are known, Avestan and Old Persian. A greater number of Middle Iranian languages (c. 300 bc-ad 950) are known; these are divided into a western and an eastern group. Modem Iranian languages fall into four groups. The southwestern group includes Modern Persian (Farsi), Dari (in northern Afghanistan), Tajiki (in Tajikistan and other Central Asian republics); Luri and Bakhtiari (in southwestern Iran); and Tat. The northwestern group includes Kurdish (spoken in Kurdistan) and Baluchi (in southwestern Pakistan, southeastern Iran, and southern Afghanistan). The southeastern group includes Pashto (in Afghanistan and

Iranian religions ► Ireland I 957

northwestern Pakistan) and the 10 or so Pamir languages (in eastern Tajikistan and adjacent parts of Afghanistan and China). The northeast¬ ern group includes Ossetic, spoken by the Ossetes in the central Cauca¬ sus Mountains, and Yaghnobi, formerly spoken in a single valley of the Pamirs. Nearly all the Modern Iranian languages have been written—if at all—in adaptations of the Arabic alphabet.

Iranian religions Ancient religions of the peoples of the Iranian pla¬ teau. The Medes and Persians were dominated by a powerful priestly tribe, the magi. The magi were responsible for chanting accounts of the origin and descent of the gods, and they were probably the source of the dualism that later characterized Zoroastrianism, the best known of the Iranian reli¬ gions. The chief god of the pre-Zoroastrian pantheon was Ahura Mazda, the creator of the universe and the one who maintains the cosmic and social order. Mithra was the second most important deity and the protec¬ tor of covenants. Other major deities included Anahita, the war goddess; Rashnu, the god of justice; and astral deities such as Tishtrya, identified with the star Sirius. The ancient Iranians did not build temples or make images of their gods, preferring to worship in the open. The central ritual was the ycizna, which consisted of a festive meal at which the worshipers made animal sacrifices and invited the deity to attend as a guest. Fire was regarded as a sacred element. The sacred drink hauma, which contained a mind-altering drug, was used to inspire worshipers with insight into truth and to stimulate warriors going into battle.

Iraq officially Republic of Iraq Country, Middle East, southwestern Asia, northwest of the Persian Gulf. Area: 167,618 sq mi (434,128 sq km). Population (2005 est.): 27,818,000. Capital: Baghdad. The population con¬

sists mainly of an Arab majority and a Kur- Dish minority. Language: Arabic (official). Religions: Islam (official; mostly Shfite); also Christianity. Currency: dinar. The country can be divided into four major regions: the Tigris-Euphrates alluvial plains in central and southeastern Iraq; Al-Jazlrah, an upland region in the north between the Tigris and Euphrates rivers; deserts in the west and south, covering about two-fifths of the country; and highlands in the northeast. Iraq has the world’s sec¬ ond largest proven reserves of petroleum, and it has substantial reserves of natural gas. Agriculture is also a major component of the economy. Iraq has a transitional government with one legislative house; its head of state is the president. Called Mesopotamia in Classical times, the region gave rise to the world’s earliest civilizations, including those of Sumer, Akkad, and Babylon. Conquered by Alexander the Great in 331 bc, the area later became a battleground between Romans and Parthians, then between Sasanians and Byzantines. Arab Muslims conquered it in the 7th century ad, and various Muslim dynasties ruled until the Mongols took over in

The Ottoman Empire took control in the 16th century and ruled until the British occupied the country during World War I (1914-18). The Brit¬ ish created the kingdom of Iraq in 1921 and occupied Iraq again during World War II (1939-45). The monarchy was restored following the war, but a revolution caused its downfall in 1958. Following a series of mili¬ tary coups, the socialist Ba'th Party, eventually led by Saddam Hussein, took control and established totalitarian rule in 1968. The I ran-Iraq War in the 1980s and the First Persian Gulf War in 1990-91 caused extensive death and destruction. The economy languished under a UN economic embargo imposed on Iraq in the 1990s. The embargo began to erode by the early 21st century, and in 2003, during the Second Persian Gulf War, the Ba'th Party was driven from power.

Irbid Town (pop., 1994: 208,329), northern Jordan. Built on Early Bronze Age settlements, it may have been the biblical city of Beth Arbel and the Arbila of the ancient Decapolis. Modern Irbid is one of Jordan’s industrial areas and an agricultural centre. The many springs in the area, in addition to the YarmOk River, provide water for irrigation. It is the home of Yarmuk University.

Iredell \ , Ir-,del\, James (b. Oct. 5, 1751, Lewes, Sussex, Eng.—d. Oct. 20, 1799, Edenton, N.C., U.S.) U.S. jurist. His family immigrated to North Carolina, where he was appointed comptroller of the customhouse at age 17. He helped draft and revise the laws of the new state of North Carolina and served as state attorney general (1779-81). He led the state’s Federal¬ ists in supporting ratification of the U.S. Constitution, and his letters in its defense (signed “Marcus”) are said to have prompted Pres. George Wash¬ ington to appoint him to the U.S. Supreme Court (1790). He wrote several notable dissents, including those for Chisholm v. Georgia (1793; affirming the subordination of the states to the federal government) and Ware v. Hyl¬ ton (1796; upholding the primacy of U.S. treaties over state statutes). His opinion in Calder v. Bull (1798) helped establish the principle of judicial review five years before it was actually tested in Marburyv. Madison.

Ireland Country, western Europe, occupying the greater part of the island of Ireland west of Great Britain. Area: 27,133 sq mi (70,273 sq km). Popu¬ lation (2005 est.): 4,096,000. Capital: Dublin. The northeastern portion of

ATLANTIC

OCEAN

Mann Mean #Carndonagh

GLENVEAGH^ -Buncrana NATIONAL PARK

Letterkenny*

Lifford * NORTHERN IRELAND

SCOTLAND

(UK.)

Donegal

(U.K.)

n ii .1 uuy y 's»»iij#Ji3nnon

** al V >D X|

' et Ballina # 3 ^ .

achill island

_ •n.-a.k-.f®*® tarrick on

Belfast

Westport* Castlebar Shannon

Clifden #

COP

arrick on

, Jhanndfi a o. .

Jalway , j-oughrea

Brandon Mountain

3,125 ^Tralee, 52°

Ballyvaghan •

T Gort glLough l WICKLQVt Ennistimon .Ennis , MTS • mMm

Kilkee Shannon $ILVERMINE ' /Carlow •.

Donegal Point * . MTS. . Arklow

Ustgll(5^?hSw' b Limerick / Kilkenny _Enniscarthy

. ,-rY .Clonmel \J Charieville GAkg New .Wextord

Oingfe ,/'' Killarney : Vil -Walerford* r §®^.'-fiosslare //’ "

KILLARNEY jf-T_ Malew .

NATIONAL PARK. Blarney. Cork . Dungaryan

'Wre - TO £Tiag^ J% ' ,h ‘i

CasHetnmnbaiC^i •

Dursey Head Ba " ,,v • C to„akilty

Mizen Head

9 2002 Encyclopaedia Britannica, Ir

the island is occupied by Northern Ireland.

Although Ireland has been invaded and colonized by Celts, Norsemen, Normans,

English, and Scots, ethnic distinctions are nonexistent. Languages: Irish, English

(both official). Religion: Christianity (predominantly Roman Catholic; also Protestant). Currency: euro. Ireland’s topography consists largely of broad lowlands drained by rivers that include the Shannon; its coasts are fringed with mountains. Nearly three-fifths of the population is urban; agriculture

958 I Ireland ► Irish literary renaissance

employs only a small percentage of the workforce. High technology, tour¬ ism, and other service industries are pivotal to the Irish economy, while mining, manufacturing, and construction also remain important. Ireland is a republic with two legislative houses; its chief of state is the president, and the head of government is the prime minister. Human settlement in Ireland began c. 6000 bc, and Celtic migration dates from c. 300 bc. St. Patrick is credited with having Christianized the country in the 5th century. Norse domination began in 795 and ended in 1014, when the Norse were defeated by Brian Boru. Gaelic Ireland’s independence ended in 1175 when Roderic O’Connor, Ireland’s high king, accepted English King Henry II as his over- lord. Beginning in the 16th century, Irish Catholic landowners fled reli¬ gious persecution by the English and were replaced by English and Scottish Protestant migrants. The United Kingdom of Great Britain and Ireland was established in 1801. The Irish Potato Famine of the 1840s led as many as 1.5 million people to emigrate, and the British government’s grudging and ineffective relief measures built momentum for Irish Home Rule. The Easter Rising (1916) was followed by virtual civil war (1919-21), during which the Irish Republican Army used guerrilla tactics to force the British gov¬ ernment to negotiate. The Catholic majority in southern Ireland favoured complete independence, and the Protestant majority in the north preferred continued union with Britain. Southern Ireland was granted dominion sta¬ tus and became the Irish Free State in 1921, and in 1937 it adopted the name Eire (Ireland) and became a sovereign independent country. It remained neutral during World War II. Britain recognized the status of Ireland in 1949 but declared that cession of the northern six counties (Northern Ire¬ land) could not occur without the consent of the Parliament of Northern Ireland. In 1973 Ireland joined the European Economic Community (later the European Community); it is now a member of the European Union. The last decades of the 20th century were dominated by sectarian hostilities between the island’s Catholics and Protestants over the status of Northern Ireland. The Irish government played a pivotal role in negotiating and win¬ ning public support for the Belfast Agreement (1998), which gave the country a consultative role in the affairs of Northern Ireland and modified Ireland’s constitution to remove its claim to the territory of the entire island.

Ireland, Northern See Northern Ireland

Irenaeus V.i-ro-'ne-os, J-ro-'na-ssV Saint (b. c. 120/140, Asia Minor—d. c. 200/203, probably Lyon; Western feast day June 28; East¬ ern feast day August 23) Bishop and theologian. Bom of Greek parents, he was a missionary to Gaul before being named bishop of Lugdunum (modern Lyon, France). All his major works, including Against Heresies, were written in opposition to Gnosticism. To counteract Gnostic influence, he promoted the development of an authoritative canon of the New Tes¬ tament. His defense of the belief that the Christian God and the God of the Old Testament were identical led to the development of the Apostles’ Creed. His writings against the Gnostics also supported the authority of the bishops, and he claimed that the bishops of various cities were known as far back as the Apostles (see apostolic succession). His works have proved a valuable source of information on the Gnostics, because he gave accurate summaries of their beliefs before refuting them.

Ireton \'Ir-t 3 n\, Henry (b. 1611, Attenborough, Nottinghamshire, Eng.—d. Nov. 28, 1651, Limerick, County Limerick, Ire.) English poli¬ tician, leader of the Parliamentary cause in the English Civil Wars. Join¬ ing the Parliamentary army at the outbreak of war, he was involved in many victories. He was elected to Parliament in 1645 and married Oliver Cromwell’s daughter in 1646. In 1647 he proposed a scheme for a con¬ stitutional monarchy; after its rejection by Charles I, Ireton provided the ideological foundations for the assault on the monarchy. He helped bring Charles to trial and was one of the signers of his death warrant. As lord deputy of Ireland and commander in chief (1650), he fought against the Roman Catholic rebels and died after the siege of Limerick.

Irgun Zvai Leumi Ur-'giin-tsvo-'e-b-u-'meX Hebrew "National Military Organization" Jewish right-wing underground movement that advocated using force to establish a Jewish state on both sides of the Jordan River. It opposed the British and the Arabs; its activities included a 1946 attack on the King David Hotel that left 91 dead and a 1947 raid on an Arab village in which all 254 inhabitants were killed. In 1943 Men- achem Begin became the movement’s leader. With Israeli independence its units disbanded. Israel’s Herut Party was its political incarnation. See also Likud; Haganah.

Irian See New Guinea

Irian Jaya See Papua

iridium \i-'ri-de-3m\ Metallic chemical element, one of the transition ele¬ ments, chemical symbol Ir, atomic number 77. A very rare, precious, sil¬ very white, hai'd, brittle metal that resists most acids, it is one of the densest substances known on Earth. It probably does not occur uncombined in nature but is found in natural alloys with other noble (i.e., chemically inactive or inert) metals. The pure metal is too hard to work with to have any significant uses; alloys with platinum are used in jewelry, pen points, surgical pins and pivots, electrical contacts and sparking points, and extru¬ sion dies. The international prototype kilogram, the primary standard (see weights and measures) for weight, is made of an alloy comprising 90% platinum and 10% iridium. The discovery of abnormally high amounts of iridium in rocks dating to the boundary between the Cretaceous and Ter¬ tiary periods led to a much-debated hypothesis that an iridium-containing asteroid striking Earth led to a catastrophic chain of events including the extinction of dinosaurs and many other forms of life.

Irigaray \e-re-ga-'ra,\ English Vir-i-.gar-eX, Luce (b. 19327, Belgium) French feminist psychoanalyst and philosopher. She examined the uses and misuses of language in relation to women in such works as Specu¬ lum of the Other Woman (1974), which argues that history and culture are written in patriarchal language and centred on men, and that the thinking of Sigmund Freud was based in misogyny. Among her other works are An Ethics of Sexual Differences (1984) and Je, tu, nous (1990).

Irigoyen \,ir-i-'go-yen\, Hipolito or Hipolito Yrigoyen (b. July 12, 1852, Buenos Aires, Arg.—d. July 3, 1933, Buenos Aires) Argentine statesman and president (1916-22, 1928-30). A lawyer, teacher, rancher, and politician, he became leader of the Radical Party in 1896. Working relentlessly for electoral reform, he succeeded in 1912 in securing a secret-ballot vote. When he was elected president in 1916, he passed measures regulating labour conditions but failed to enforce them, and a serious strike was violently broken in 1919. Corruption and the failure to implement democratic reforms cost him support after his return to power in 1928, and he was further weakened by the Great Depression. A nearly bloodless military coup ended his career.

iris family Family Iridaceae, composed of about 1,700 species of peren¬ nial herbaceous plants, as well as a few shrubs, in some 80 genera. It is known for ornamentals such as irises (genus Iris), gladioli (see gladiolus), CROCUSes, and freesias. Irises have swordlike, smooth leaves and bear showy flowers in a great variety of colours and sizes on a smooth stem. Most abundant and diverse in Africa, they are found nearly worldwide across temperate, subtropical, and tropical zones. The underground stems may be rhizomes (e.g.. New World Iris species), bulbs (e.g., southwestern European Iris species), or corms (e.g., Gladiolus).

Irish elk Any member of a genus ( Megaloceros) of extinct giant deer commonly found as fossils in Pleistocene deposits (1.8 million-10,000 years ago) in Europe and Asia. About the size of a modem moose, the Irish elk had the largest antlers of any form of deer known, in some speci¬ mens about 13 ft (4 m) across. It may have survived until c. 700-500 bc.

Irish Free State See Ireland Irish Home Rule See Irish Home Rule

Irish language or Gaelic language Celtic language of Ireland, written in the Latin alphabet introduced with Christianity in the 5th cen¬ tury. Irish is conventionally divided into three periods: Old Irish (600-c. 950), Middle Irish (c. 950-1200), and Modern Irish (from c. 1200). Ogham writing predates Old Irish. Old and Middle Irish are the vehicles of a rich literature of prose tales and verse. Classical Modern Irish was the exclusive literary medium in Ireland and Scottish Gaeldom into mod¬ em times (see Scottish Gaelic language). Literacy in Irish declined under English rule; by 1800 it was all but an unwritten language. The deaths and emigration resulting from the Irish Potato Famine and a massive shift to English afterward drastically reduced the number of Irish-speakers. Irish was revived as a literary language in the late 19th and early 20th centuries, and with Irish independence (1921) it was made official. Though it is a true community language only for a small number of people on Ireland’s western coast in what are called Gaeltachts, hundreds of thousands of Irish citizens and people of Irish descent have some com¬ petence in Irish.

Irish literary renaissance Flowering of Irish literary talent in the late 19th and early 20th century. It was closely allied with a strong politi¬

cs) 2006 Encyclopaedia Britannica, Inc.

Irish Potato Famine ► ironclad I 959

cal nationalism and a revival of interest in Ireland’s Gaelic heritage (see Gaelic revival). Other factors in the renaissance were the retelling of ancient heroic legends in books such as Standish O’Grady’s History of Ireland (1878, 1880) and Douglas Hyde’s A Literary History of Ireland (1899), and the Gaelic League, formed in 1893 to revive the Irish lan¬ guage and culture. It developed into a vigorous literary force centred on William Butler Yeats; other important figures were Augusta Gregory, John Millington Synge, and Sean O'Casey. See also Abbey Theatre.

Irish Potato Famine (1845-49) Famine that occurred in Ireland when the potato crop failed in successive years. By the early 1840s almost half the Irish population, particularly the rural poor, was depending almost entirely on the potato for nourishment. A reliance on only one or two high-yielding varieties made the crop vulnerable to disease, including the late blight fungus, which ruined the crop. The British government pro¬ vided minimal relief to the starving Irish, limited to loans and soup kitch¬ ens. The famine was a watershed in Ireland’s demographic history: more than a million people died from starvation or famine-related diseases, and perhaps as many as 1.5 million emigrated to North America and Britain. Population continued to decline thereafter, and by independence in 1921 the Irish population was barely half of the 8.4 million it had been before the famine.

Irish Rebellion See Easter Rising

Irish Republican Army (IRA) Republican paramilitary organization, founded in 1919, seeking the end of British rule in Northern Ireland and the unification of the province with the republic of Ireland. The IRA used armed force to achieve the same objectives as Sinn Fein, though the two always operated independently. After the establishment of the Irish Free State (1922), the IRA refused to accept a separate Northern Ireland, and the violence continued. The IRA was declared illegal in 1931, and the Irish legislature provided for internment without trial for its members. It gained popular support in the 1960s when Roman Catholics in Northern Ireland began a civil rights campaign against discrimination by the domi¬ nant Protestant majority. In 1969 the IRA split into the Marxist Official wing, which eschewed violence, and the Provisionals (Provos), Ulster Catholics committed to the use of terror tactics against Ulster Protestants and the British military, tactics that included the 1979 assassination of Lord Mountbaiten and the killing of some 1,800 people by the early 1990s. In 1994 the IRA declared a cease-fire, and its political representatives were included in multiparty talks beginning in 1997. Negotiations pro¬ duced the Good Friday Agreement (1998), in which the IRA agreed to decommission (disarm). In the ensuing years the IRA destroyed some of its weapons but resisted decommissioning its entire armoury, hampering implementation of the peace agreement. In July 2005, however, the IRA announced that it was ending its armed campaign and instead would pur¬ sue only peaceful means to achieve its objectives.

Irish Sea Arm of the North Atlantic Ocean that separates Ireland from Great Britain. Connected with the Atlantic by North Channel and by St. George’s Channel, it is about 130 mi (210 km) long and 150 mi (240 km) wide. Its total area is about 40,000 sq mi (100,000 sq km). Its greatest depth measures about 576 ft (175 m). The Isle of Man and Anglesey are its two principal islands.

Irish terrier Breed of terrier developed in Ireland, one of the oldest ter¬ rier breeds. It stands 16-18 in.

(41.5-46 cm) high, weighs 22-26 lbs (10-12 kg), and has a wiry golden- red to reddish brown coat. Nick¬ named the daredevil, it is reputedly adaptable, loyal, spirited, and reck¬ lessly courageous. It served as a messenger and sentinel in World War I, and has been used to hunt and to retrieve game.

Irish wolfhound Tallest of all dog breeds, a keen-sighted hound used in Ireland to hunt wolves and other game and noted for its speed and strength. An ancient breed, first mentioned about the 2nd century ad, it is similar in build to the greyhound but far more powerful. The female, substantially smaller than the male, stands at least 30 in. (76 cm) tall and weighs 105 lb (48 kg) or more. The rough coat is long on the brows and

underjaw, and the colours include gray, brindle, red-brown, black, and white. The dog is valued as a gentle, even-tempered companion.

Irkutsk \ir-'kiitsk\ City (pop., 2001 est.: 587,200), east-central Russia. Located on the Angara River, it was founded as a wintering camp in 1652. It soon became a commercial centre for the fur trade and a base on the Russian trade route to China and Mongolia. Its importance grew after the opening of the Trans-Siberian Railroad in 1898. An industrial and cultural centre, it is the seat of Irkutsk State University and the Siberian branch of the Academy of Sciences.

iron Metallic chemical element, one of the transition elements, chemical symbol Fe, atomic number 26. Iron is the most used and cheapest metal, the second most abundant metal and fourth most abundant element in Earth’s crust. It occurs rarely as a free metal, occasionally in natural alloys (especially in meteorites), and in hundreds of minerals and ores, including hematite, magnetite, limonite, and siderite. The human body contains about one-sixth of an ounce (4.5 g) of iron, mostly in hemoglobin and its pre¬ cursors; iron in the diet is essential to health. Iron is ferromagnetic (see ferromagnetism) at ordinary temperatures and is the only metal that can be tempered (see tempering). Its uses in steels of various types, as well as in cast and wrought iron (collectively, “ferrous metals”), are numerous. Alteration of its properties by impurities, especially carbon, is the basis of steelmaking. Iron in compounds usually has valence 2 (ferrous) or 3 (ferric). Ferrous and ferric oxides (FeO and Fe 2 0 3 , respectively) are used as pigments and the latter as jewelers’ rouge. Rust is ferric oxide con¬ taining water; ferric oxide is widely used as a magnetic recording mate¬ rial in computer data-storage devices and magnetic tapes. Ferrous and ferric sulfates and chlorides are all of industrial importance as mordants, reducing agents, flocculating agents, or raw materials and in inks and fer¬ tilizers.

Iron Act (1750) Measure by the British Parliament to restrict the Ameri¬ can colonial iron industry. Pig iron and iron bar could be exported to England duty-free to meet British needs. Further development of colonial manufacturing to produce finished iron goods was prohibited, as was the export of iron to other countries.

Iron Age Final technological and cultural stage in the Stone-Bronze- Iron-Age sequence (or Three-Age System) in which iron largely replaced bronze in implements and weapons. The start of the Iron Age varied geo¬ graphically, beginning in the Middle East and southeastern Europe c. 1200 bc but in China not until c. 600 bc. Though the large-scale production of iron implements brought new patterns of more permanent settlement, use of iron for weapons put arms in the hands of the masses for the first time and set off a series of large-scale movements and conquests that did not end for 2,000 years and that changed the face of Europe and Asia. See also Bronze Age.

Iron Curtain Political, military, and ideological barrier erected by the Soviet Union after World War II to seal off itself and its dependent east¬ ern European allies from open contact with the West and other noncom¬ munist areas. Winston Churchill employed the term in a speech in Fulton, Mo., U.S., about the division of Europe in 1946. The restrictions and the rigidity of the Iron Curtain eased slightly after Joseph Stalin’s death in 1953, though the construction of the Berlin Wall in 1961 restored them. The Iron Curtain largely ceased to exist in 1989-90 with the communists’ abandonment of one-party rule in eastern Europe.

iron-deficiency anemia Most common type of anemia, which may develop in times of high iron loss and depletion of iron stores (e.g., rapid growth, pregnancy, menstruation) or in settings of low dietary iron intake or inefficient iron uptake (e.g., starvation, intestinal parasites, gastrec¬ tomy). Much of the world’s population is iron-deficient to some degree. Symptoms include low energy level and sometimes paleness, shortness of breath, cold extremities, sore tongue, or dry skin. In advanced cases, red blood cells are small, pale, and low in hemoglobin, blood iron levels are reduced, and body iron stores are depleted. Treatment with iron usually brings quick improvement.

iron ore, bog See bog iron ore

iron pyrite See pyrite

ironclad Type of warship developed in Europe and the U.S. in the mid- 19th century, characterized by the iron armour that protected the hull. In the Crimean War (1853-56) the French and British successfully attacked Russian fortifications with “floating batteries,” ironclad barges mounting

Irish terrier

SALLY ANNE THOMPSON/EB INC.

960 I Irons ► irrigation

heavy guns. In 1859 the French completed the first iron warship, the Gloire ; its iron plates, 4.5 in. (11 cm) thick, were backed by heavy tim¬ ber. Britain and the U.S. soon followed. Union forces launched armored gunboats on the Mississippi at the start of the American Civil War, and a flotilla captured Fort Henry (1862). The first battle between ironclads was the Battle of the Monitor and Merrimack (1862). Later refinements led to the battleship. See also monitor.

French ironclad Gloire, engraving by Smythe after a painting by A.W. Weedon

COURTESY OF THE TRUSTEES OF THE BRITISH MUSEUM; PHOTOGRAPH, J.R. FREEMAN & CO. LTD.

Irons, Jeremy (b. Sept. 19, 1948, Cowes, Isle of Wight, Eng.) British actor. He made his London stage debut in Godspell (1973) and appeared on Broadway in The Real Thing (1984, Tony Award). After his screen debut in Nijinsky (1980), he won notice for The French Lieutenant’s Woman (1981) and became widely popular in the television series Brides- head Revisited (1980-81). His performances were notable for their sen¬ sitivity and sophistication, and he offered deliciously wicked turns in Dead Ringers (1988) and Reversal of Fortune (1990, Academy Award). His later films include Damage (1992), The Lion King (1994), and Lolita

(1997).

iron weed Any of about 500 species genus Vernonia (family Asteraceae).

Small herbaceous (nonwoody) spe¬ cies are found throughout the world; shrubs and trees are found primarily in tropical regions. Iron weed species have lance-shaped, toothed leaves that alternate along the stem; clusters of flower heads composed only of disk flowers (no ray flowers); and a ring of overlapping bracts below the flower heads. Some autumn¬ blooming species are cultivated as border plants for their attractive white, purple, or pink flower clus¬ ters.

iron wood Any of numerous trees and shrubs, found worldwide, that have exceptionally tough or hard wood useful for timber, fence posts, and tool handles. Species include the eastern, or American, hop hornbeam (Ostrya virginiana ), a small tree of northern Iran (. Parrotia persica ), and Ceylon ironwood (Mesua ferrea). Though these trees belong to different plant orders, all have bright yellow to orange and scarlet autumn foliage.

irony Language device in which the real intent is concealed or contra¬ dicted by the literal meaning of words or a situation. Verbal irony, either spoken or written, arises from an awareness of contrast between what is and what ought to be. Dramatic irony, an incongruity in a theatrical work between what is expected and what occurs, depends on the structure of a play rather than its use of words, and it is often created by the audience’s awareness of a fate in store for the characters that they themselves do not suspect. See also figure of speech.

Iroquoian Vir-o-.kwoi-onX languages Family of about 16 North American Indian languages aboriginally spoken around the eastern Great Lakes and in parts of the Middle Atlantic states and the South. Aside from the languages of the Iroquois Confederacy (Mohawk, Oneida, Onondaga, Cayuga, and Seneca, all originally spoken in New York, along with Tus- carora, originally spoken in North Carolina) and Cherokee (originally spoken in the southern Appalachians), the Iroquoian languages are extinct, and with the exception of Huron and Wyandot, the extinct languages are poorly documented. Iroquoian languages are remarkable for their gram¬ matical intricacy. Much of a sentence’s semantic content is bound around a verbal base, so a single very long word may constitute a fairly complex utterance.

Iroquois \'ir-3-,kw6i\ Any of six North American members of the Iro¬ quois Confederacy living mostly in southern Ontario and Quebec, Can., and in New York, Wisconsin, Ohio, and Oklahoma, U.S. The name Iro¬ quois is a French derivation of Irinakhoiw, meaning “Rattlesnakes,” their Algonquian enemy’s epithet. They call themselves Hodenosaunee, mean¬ ing “People of the Longhouse.” The Iroquois were semi sedentary, prac¬ ticed agriculture, palisaded their villages, and dwelled in longhouses that lodged many families. Women worked the fields and, when they became clan elders, helped determine the makeup of village councils. Men built houses, hunted, fished, and made war. Iroquoian mythology was largely preoccupied with supernatural aggression and cruelty, sorcery, torture, and cannibalism. Their formal religion consisted of agricultural festivals. War¬ fare was ingrained in Iroquois society, and war captives were often tor¬ tured for days or made permanent slaves. All together the various Iroquois tribes number about 70,000 members, with the Mohawk making up more than half that figure.

Iroquois Confederacy or League of the Iroquois Confedera¬ tion of five (later six) Indian tribes across upper New York that in the 17th—18th century played a strategic role in the struggle between the French and British for supremacy in North America. The five original nations were the Mohawk, Oneida, Onondaga, Cayuga, and Seneca; the Tuscarora, a non-voting member, joined in 1722. According to tradition, the confederacy was founded between 1570 and 1600 by Dekanawidah, bom a Huron (see Wyandot), carrying out the earlier ideas of Hiawatha, an Onondaga. Cemented mainly by their desire to stand together against invasion, the tribes united in a common council composed of 50 sachems; each original tribe had one vote, and unanimity was the rule. At first the confederacy barely withstood attacks from the Huron and Mahican, but by 1628 the Mohawk had defeated the Mahican and established them¬ selves as the region’s dominant tribe. When the Iroquois destroyed the Huron in 1648-50, they were attacked by the Huron’s French allies. Dur¬ ing the American Revolution, the Oneida and Tuscarora sided with the American colonists while the rest of the league, led by Joseph Brant, fought for the British. The loyalist Iroquois were defeated in 1779 near Elmira, N.Y., and the confederacy came to an end.

irrational number Among the real numbers, any of those that cannot be represented as quotients of integers. In decimal form, irrational num¬ bers are represented by nonterminating, nonrepeating decimals. Examples include square roots of prime numbers and such transcendental numbers as k and e.

Irrawaddy \,ir-a-'wa-de\ River River, Myanmar (Burma). It flows 1,350 mi (2,170 km) across the centre of the country and empties into the Bay of Bengal. The country’s most important commercial waterway, it is formed by the confluence of the Nmai and the Mali rivers; in the central dry zone it is joined by its major tributary, the Chindwin River. Chief ports are Mandalay, Chauk, Prome (Pye), and Henzada.

irrigation Artificial supply of water to land, to maintain or increase yields of food crops, a critical element of modern agriculture. Irrigation can compensate for the naturally variable rate and volume of rain. Water is pumped from natural ponds, lakes, streams, and wells; basin systems and dams hold back larger streams and annual floods. Below the dam, gates to concrete-lined canals are opened, conveying the water over the land through gravity flow. More elaborate, expensive canals flow from huge constructed reservoirs, which hold a year-round water supply. Today portable irrigation systems of lightweight aluminum pipe are in wide use. Drip irrigation, a newer method, uses narrow tubing to supply water directly to the base of each plant. Agricultural irrigation, water towers, and machines invented to lift and distribute water are ancient innovations. Early Egyptians were irrigating with Nile River water by 5000 bc, and

of perennial plants constituting the

Western ironweed (Vernonia fascicu- lata )

DAN MORRILL

irritable bowel syndrome ► Isabella II I 961

such other ancient civilizations as Babylon and China seem to have devel¬ oped largely as a result of irrigation-based agriculture.

irritable bowel syndrome or IBS Chronic disorder characterized by abdominal pain, intestinal gas, and diarrhea, constipation, or both. Other symptoms may include abdominal pain that is relieved after def¬ ecation or a sensation of incomplete rectal evacuation. IBS is caused by a motility disturbance of the intestines that may result from increased intestinal sensitivity to distension. Stress or the consumption of fatty foods, milk products, certain fruits or vegetables (e.g., broccoli and cab¬ bage), alcohol, or caffeine may cause similar symptoms. Treatment includes relaxation, exercise, and avoidance of aggravating foods. Antid- iarrheal medications or fibre supplements may help lessen symptoms. Although IBS may cause discomfort and emotional distress, the disorder does not result in any permanent intestinal damage.

Irtysh \ir-'tosh\ River Kazakh Ertis \er-'tis\ River rising in the Altai Mountains in Xinjiang autonomous region, China. It flows west across the Chinese border and then northwest through Kazakhstan into Russian Sibe¬ ria, where it becomes the largest tributary of the Ob River. It is 2,640 mi (4,248 km) long and is navigable for most of its course. Its main ports include Tobolsk, Tara, Omsk, Pavlodar, Semey, and Oskemen.

Iruna See Pamplona

Irvine Royal burgh and seaport (pop., 1991: 32,988), North Ayrshire council area, on the Atlantic coast of Scotland. The last of Scotland’s five new towns, it was designated in 1967 to house overflow population from Glasgow and provide a focus for the economic and industrial rehabilita¬ tion of the area. It had declined in the 18th and 19th centuries because of competition from other towns and the silting of the harbour. It became an industrial centre that produces chemicals, engineering, electrical goods, and clothing.

Irving City (pop., 2000: 191,615), northeastern Texas, U.S. Established in 1903 and incorporated in 1914, the city developed into an industrial hub during the 1950s. A suburb of Dallas, it is the site of the University of Dallas and DeVry University as well as of Texas Stadium, home of the Dallas Cowboys professional gridiron football team.

Irving, Sir Henry orig. John Henry Brodribb (b. Feb. 6, 1838, Keinton Mandeville, Somerset, Eng.—d. Oct. 13, 1905, Bradford, York¬ shire) British actor. He toured for 10 years with a stock company before making his London debut in 1866. With his success in The Bells (1871), he became a leading actor in H.L. Bateman’s company (1871-77). As actor- manager of the Lyceum Theatre (from 1878), he made it London’s most successful theatre. He formed a celebrated acting partnership with Ellen Terry that lasted until the company dissolved in 1902. They were noted for their Shakespearean roles, and their theatrical qualities complemented each other: he the brooding introvert, she the spontaneous charmer.

Irving, John (Winslow) (b. March 2, 1942, Exeter, N.H., U.S.) U.S. novelist. He taught at several universities before beginning to write full¬ time in the late 1970s. His best-selling The World According to Garp (1978; film, 1982) is notable, like his other works, for its engaging story line, colourful characterizations, macabre humour, and examination of contemporary issues. Later novels include The Hotel New Hampshire (1981; film, 1984), The Cider House Rules (1985; film, 1999), and A Prayer for Owen Meany (1989).

Irving, Washington (b. April 3,

1783, New York, N.Y., U.S.—d.

Nov. 28, 1859, Tarrytown, N.Y.)

U.S. author, called the “first Ameri¬ can man of letters.” He began his career as a lawyer but soon became a leader of the group that published Salmagundi (1807-08), a periodical containing whimsical essays and poems. After his comic A History of New York...by Diedrich Knicker¬ bocker (1809), he wrote little until his very successful The Sketch Book (1819-20), containing his best- known stories, “The Legend of Sleepy Hollow” and “Rip Van

Winkle.” It was followed by a sequel, Bracebridge Hall (1822). He held diplomatic positions in Madrid, Spain, and writings such as The Alham¬ bra (1832) reflect his interest in Spain’s past.

Isaac \e-'zak\, Heinrich (b. c. 1450, Brabant—d. 1517, Florence) Flem¬ ish composer. He spent much of his career in Italy, especially Florence, but was known as a leading representative of the Netherlandish style. As court composer to Emperor Maximilian I (from 1497), he was allowed to travel. He had many students, including Ludwig Senfl, and his historical importance in Germany is as the main disseminator of the progressive Northern style there. The beauty and quality of his works, which include over 100 masses, dozens of motets, and secular songs, have led some to regard him as second only to Josquin des Prez among his contemporaries.

Isaac II Angelus (b. c. 1135—d. February 1204) Byzantine emperor (1185-95). Proclaimed emperor by the Constantinople mob that murdered his cousin, Andronicus I Comnenus, he drove the Normans out of Greece (1185) but failed to regain Cyprus from rebels. He was forced to help Frederick I Barbarossa in the Third Crusade. He defeated the Serbians (1190), but before he could carry out a planned expedition against the Bulgarians, he was overthrown by his brother, who imprisoned and blinded him (1195). His son Alexius diverted the Fourth Crusade to restore him to power (1203), and father and son briefly ruled as co-emperors before being dethroned and killed in a revolution.

Isaac of Stella (b. c. 1100, England—d. c. 1169, Etoile, near Poitiers, Aquitaine) Monk, philosopher, and theologian. Isaac joined the Cistercians during the reforms carried out by St. Bernard de Clairvaux. His scholarly works make use of logical argumentation and are influenced by the Neo¬ platonism of St. Augustine. His principal work, Letter to Alcher on the Soul (1162), integrates Aristotelian and Neoplatonic psychological theories with Christian mysticism. A leader of humanism in his day, he suggests that the intellect enables humans to grasp eternal ideas in time and that intelligence allows humans to intuit the reality of God.

Isaac the Elder See Isaac ben Solomon Israeli

Isabela Island Island, Galapagos Islands, Ecuador. It is the largest of the Galapagos Islands, located in the eastern Pacific Ocean west of main¬ land Ecuador. It has an area of 2,249 sq mi (5,825 sq km), and its north¬ ern tip, Albemarle, is crossed by the Equator. It has unique species of flightless cormorants and penguins as well as large numbers of iguanas and a flamingo colony.

Isabella I known as Isabella the Catholic Spanish Isabel la Catolica (b. April 22, 1451, Mad¬ rigal de las Altas Torres, Castile—d.

Nov. 26, 1504, Medina del Campo,

Spain) Queen of Castile (1474- 1504) and of Aragon (1479-1504).

Daughter of John II of Castile and Leon, she married Ferdinand V in 1469. Her reign began with civil war over her succession (1474-79), but in 1479 the kingdoms of Castile and Aragon came together in the persons of their rulers, though they remained separately governed. In a long cam¬ paign (1482-92), Isabella and Ferdi¬ nand succeeded in conquering Granada, the last Muslim stronghold in Spain. In 1492 Isabella approved support of Christopher Columbus’s journey to the New World. That same year she was involved in the expulsion of the Jews under the Inquisition. Along with her spiritual advisers, she reformed the Spanish churches.

Isabella II Spanish Isabel \e-sa-'bel\ (b. Oct. 10, 1830, Madrid, Spain—d. April 9, 1904, Paris, France) Queen of Spain (1833-68). She was the daughter of Ferdinand VII, and the issue of her succession to the throne precipitated the First Carlist War (see Carlism). During her minor¬ ity ( 1 833—43), her mother and Baldomero Espartero acted as regents; in 1843 Espartero was deposed by military officers, and Isabella was declared of age. Liberal opposition to the regime’s authoritarianism, scan-

Washington Irving, oil painting by J.W. Jarvis, 1809; in the Historic Hudson Valley collection.

COURTESY OF HISTORIC HUDSON VALLEY

Isabella I, portrait by an unknown art¬ ist; in the Real Academia de la Histo- ria, Madrid, Spain.

ARCHIVO MAS, BARCELONA

962 I Isabella Farnese ► Ishtar Gate

dalous reports about her private life, and her arbitrary political interfer¬ ence led to the Revolution of 1868, which drove her into exile. She abdicated in favour of her son, Alfonso XII.

Isabella Farnese \far-'na-za\ (b. Oct. 25, 1692, Parma, Duchy of Parma—d. July 11, 1766, Aranjuez, Spain) Queen consort of Philip V of Spain. A member of the ducal Farnese family of Parma, she became Phil¬ ip’s second wife in 1714 and quickly established ascendancy over her weak husband. Because his two sons by his first wife were in line to suc¬ ceed him, she sought to secure Italian possessions for her own children, including Charles III. This quest embroiled Spain in wars and intrigues for three decades. However, she chose able and devoted ministers, who intro¬ duced beneficial internal reforms and improved Spain’s economy. After Philip’s death in 1746, she ceased to exert any real influence.

Isaiah \I-'za-o\ (fl. 8th century bc, Jerusalem) Prophet of ancient Israel after whom the biblical book of Isaiah is named. He is believed to have written only some of the book’s first 39 chapters; the rest are by one or more unknown authors. Isaiah’s call to prophesy came c. 742 bc, when Assyria was beginning the westward expansion that later overran Israel. A contemporary of Amos, Isaiah denounced economic and social injus¬ tice among the Israelites and urged them to obey the Law or risk cancel¬ lation of God’s covenant. He correctly predicted the destruction of Samaria, or northern Israel, in 722 bc, and he declared the Assyrians to be the instrument of God’s wrath. The Christian Gospels lean more heavily on the book of Isaiah than on any other prophetic text, and its “swords-into-plowshares” passage has universal appeal.

ISBN See International Standard Book Number

Ischia \'is-ke-3\ Island, southern Italy. Located in the Tyrrhenian Sea between the Gulf of Gaeta and the Bay of Naples, it has a circumference of 21 mi (34 km) and an area of 18 sq mi (47 sq km) and consists almost entirely of volcanic rock. It rises to 2,585 ft (788 m) at Monte Epomeo, an extinct volcano, which gives its name to the island’s famous wine. Known for its mild climate and mineral springs, it is a popular resort area. The chief towns, including Ischia, are located in the north.

ISDN in full Integrated Services Digital Network Digital tele¬ communications network that operates over standard copper telephone wires or other media. ISDN connections are used to provide a variety of digital services to customers, including digital voice telephone, fax, e-mail, digital video, and access to the Internet. A wide range of data transfer rates are available, with speeds up to about 128 kilobits per second (kbps). ISDN is faster than an ordinary dial-up connection (at about 56 kbps), but much slower than cable modem or DSL connections (which typically exceed one megabit per second).

Ise Shrine in full Grand Shrine of Ise Japanese Ise-daijingu

Foremost Shinto shrine in Japan, at Ise, in southern Honshu. The Inner Shrine (traditionally founded 4 bc) is dedicated to the sun goddess Amat- erasu. The Outer Shrine (5th century),

4 mi (6 km) away, is dedicated to Toyuke Okami, god of food, cloth¬ ing, and housing. At both shrines the main building is a thatched hut built in the ancient Japanese style of unpainted Japanese cypress (hinoki).

A distinctive feature of Shinto archi¬ tecture is the chigi, a scissor-shaped finial at the front and rear of the roof.

Since the 7th century the buildings have been reconstructed every 20 or 21 years.

Iseo Ve-'za-oV, Lake Lake, north¬ ern Italy. Situated at the southern foot of the Alps, it is fed by the Oglio River, which enters the northern end near Lovere and leaves the southern end at Sarnico. It is 15.5 mi (25 km) long, with a surface area of 24 sq mi (62 sq km). Monte Isola, a large island in the centre of the lake, is crowned by a chapel.

Isere River \e-'zer\ River, southwestern France. Originating in the Savoy Alps on the Italian frontier, it flows 180 mi (290 km) southwest to its confluence with the Rhone River above Valence. It is unnavigable but used for hydroelectric power.

Isfahan See Esfahan

Isherwood, Christopher orig. Christopher William Brad¬ shaw (b. Aug. 26, 1904, High Lane, Cheshire, Eng.—d. Jan. 4, 1986, Santa Monica, Calif., U.S.) British-born U.S. writer. Educated at Cam¬ bridge University, he became close friends with W.H. Auden, with whom he traveled and collaborated on three verse dramas, including The Ascent ofF6 (1936). He lived in Berlin from 1929 to 1933; his two novels about this period, later published together as The Berlin Stories (1946), inspired the play I Am a Camera (1951; film, 1955) and the musical Cabaret (1966; film, 1972). A pacifist, he moved to southern California at the beginning of World War II, where he taught and wrote screenplays. His later fiction and memoirs reflect his homosexuality. A follower of Swami Prabha- vananda, he wrote and translated works on Indian Vedanta.

Ishikari \,e-she-'ka-re\ River River, Hokkaido, northern Japan. Rising near the centre of the Kitami Mountains, it flows southwest to empty into Ishikari Bay of the Sea of Japan (East Sea). It is 227 mi (365 km) long, the second longest river in Japan. Its name is derived from the Ainu term ishikaribetsu (“greatly meandering river”).

Ishim \i-'shim\ River Kazakh Esil \'es-il\ River, north-central Kazakh¬ stan and the Tyumen and Omsk provinces of south-central Russia. A tributary of the Irtysh River, it rises in the Niyaz Hills in the north of the Kazakh Uplands, flowing northwest before entering the Irtysh at Ust- Ishim. It is 1,522 mi (2,450 km) long.

Ishmael ben Elisha Vish-ma-sl-.ben-i-Ti-shaV (fl. 2nd century ad) Jewish scholar. Bom into a wealthy priestly family, he was taken captive by the Roman legions that sacked Jerusalem in ad 70, but he was ransomed by his former teacher and was sent back to Palestine to study. Ishmael founded a rabbinic school and wrote commentaries on the Torah, devel¬ oping 13 rules of exegesis based on the 7 rules of Hillel. Known for his simple, literal approach to biblical scholarship, he sought to relieve hard¬ ship for observant Jews in the interpretation of the Law. He is often por¬ trayed in dispute with Akiba ben Joseph for what he saw as the latter’s excessive interpretations of superficial biblical words or phrases.

Ishtar In Mesopotamian religion, the goddess of war and sexual love. Known as Ishtar in Akkadia, she was called Astarte by western Semitic peoples and was identified with Inanna in Sumeria. In early Sumeria she was the goddess of the storehouse as well as of rain and thunderstorms. Once a fertility goddess, she evolved into a deity of contradictory quali¬ ties, of joy and sorrow, fair play and enmity. In Akkadia she was asso¬ ciated with the planet Venus and was the patroness of prostitutes and alehouses. Her popularity became universal in the ancient Middle East, and she was called Queen of the Universe.

Ishtar, with her cult-animal the lion, and a worshipper, modern impression from a cylinder seal, c. 2300 bc; in the Oriental Institute, University of Chicago

COURTESY OF THE ORIENTAL INSTITUTE, UNIVERSITY OF CHICAGO

Ishtar Gate Enormous burnt-brick double entryway built in the ancient city of Babylon c. 575 bc. The gate was more than 38 ft (12 m) high and was decorated with glazed brick reliefs. Through the gatehouse ran the stone- and brick-paved Processional Way. Some 120 brick lions lined the street and some 575 dragons and bulls, in 13 rows, adorned the gate.

Entrance to the Outer Shrine of the Grand Shrine of Ise, Japan.

FPG-EB INC.

Isidore of Sevilla ► island I 963

Isidore of Sevilla, Saint (b. c. 560, Cartagena or Sevilla, Spain—d. April 4, 636, Sevilla; canonized 1598; feast day April 4) Spanish prelate and scholar, last of the Western Fathers of the Church. He became arch¬ bishop of Sevilla c. 600 and presided over several councils that shaped church policy, including the fourth Council of Toledo (633). He also pro¬ moted the conversion of the Visigoths from Arianism to orthodox Chris¬ tianity. His best-known work was Etymologies, an encyclopedia that became a standard reference work in the Middle Ages. He also wrote theological works, biographies, and treatises on natural science, cosmol¬ ogy, and history. He was canonized in 1598 and declared a Doctor of the Church in 1722.

isinglass See muscovite

Isis \'I-S3s\ One of the major goddesses of ancient Egypt, the wife of Osiris. When Osiris was killed by Seth, she gathered up the pieces of his body, mourned for him, and brought him back to life. She hid their son Horus from Seth until Horns was fully grown and could avenge his father. Worshiped as a goddess of protection, she had great magical powers and was invoked to heal the sick or protect the dead. By Greco-Roman times she was dominant among Egyptian goddesses, and her cult reached much of the Roman world as a mystery religion.

ISKCON See Hare Krishna movement Isla de Pasqua See Easter Island

Islam Major world religion founded by Muhammad in Arabia in the early 7th century ad. The Arabic word islam means “submission”—specifically, submission to the will of the one God, called Allah in Arabic. Islam is a strictly monotheistic religion, and its adherents, called Muslims, regard the Prophet Muhammad as the last and most perfect of God’s messen¬ gers, who include Adam, Abraham, Moses, Jesus, and others. The sacred scripture of Islam is the Qur’an, which contains God’s revelations to Muhammad. The sayings and deeds of the Prophet recounted in the sunna are also an important source of belief and practice in Islam. The religious obligations of all Muslims are summed up in the Five Pillars of Islam, which include belief in God and his Prophet and obligations of prayer, charity, pilgrimage, and fasting. The fundamental concept in Islam is the SHARfAH, or Law, which embraces the total way of life commanded by God. Observant Muslims pray five times a day and join in community worship on Fridays at the mosque, where worship is led by an imam. Every believer is required to make a pilgrimage to Mecca, the holiest city, at least once in a lifetime, barring poverty or physical incapacity. The month of Ramadan is set aside for fasting. Alcohol and pork are always forbid¬ den, as are gambling, usury, fraud, slander, and the making of images. In addition to celebrating the breaking of the fast of Ramadan, Muslims cel¬ ebrate Muhammad’s birthday (see mawlid) and his ascension into heaven (see mi'raj). The Td al-Adha festival inaugurates the season of pilgrimage to Mecca. Muslims are enjoined to defend Islam against unbelievers through jihad. Divisions occurred early in Islam, brought about by dis¬ putes over the succession to the caliphate (see caliph). About 90% of Mus¬ lims belong to the Sunnite branch. The ShUtes broke away in the 7th century and later gave rise to other sects, including the IsmATus. Another significant element in Islam is the mysticism known as Sufism. Since the 19th century the concept of the Islamic community has inspired Muslim peoples to cast off Western colonial rule, and in the late 20th century fun¬ damentalist movements (see Islamic fundamentalism) threatened or toppled a number of secular Middle Eastern governments. In the early 21st cen¬ tury, there were more than 1.2 billion Muslims in the world.

Islam, Nation of See Nation of Islam

Islam, Pillars of Five duties incumbent on every Muslim. The first is the profession of faith in the one God and in Muhammad as his Prophet. The others are prayer five times a day, the giving of alms to the poor, fasting during the month of Ramadan, and the hajj, or pilgrimage to Mecca.

Islamabad \is-Ta-m9-,bad\ Capital (pop., 1998: 524,500) of Pakistan, located northeast of Rawalpindi. Established in 1959 to replace Karachi as the capital, it was designed to blend modern and traditional Islamic archi¬ tecture. The city itself is small, with an area of 25 sq mi (65 sq km), but the planned capital area is a 350-sq-mi (910-sq-km) expanse of natural terraces and meadows surrounding the city. It is the seat of the Univer¬ sity of Islamabad (founded 1965).

IslambGli \ l is-lam-'bu-le\, Khalid al- or Khaled Islambouli (b.

1958, near Al-Minya, Egypt—d. April 15, 1982, Egypt) Egyptian radical,

assassin of Anwar el-Sadat. Born into a family of rural notables, he attended Egypt’s military academy and was assigned to the artillery corps as a lieutenant. Furious at the arrest of his brother, a leader of the Islam¬ ist opposition to Sadat, he joined the radical Islamic Jihad Group (Jama'at al-Jihad al-Islaml), and, along with a group of accomplices, assassinated Sadat during a parade in 1981. He was executed following a public trial.

Islamic arts Visual, literary, and performing arts of the populations that adopted Islam from the 7th century. Islamic visual arts are decorative, colourful, and, in religious art, nonrepresentational; the characteristic Islamic decoration is the arabesque. From ad 750 to the mid 11th century, ceramics, glass, metalwork, textiles, illuminated manuscripts, and wood¬ work flourished; lustred glass became the greatest Islamic contribution to ceramics. Manuscript illumination became an important and greatly respected art, and miniature painting flourished in Iran after the Mongol invasions (1220-60). Calligraphy, an essential aspect of written Arabic, developed in manuscripts and architectural decoration. Islamic architec¬ ture finds its highest expression in the mosque and related religious build¬ ings. Early Islamic religious architecture drew upon Christian architectural features such as domes, columnar arches, and mosaics, but also included large courtyards for congregational prayer. Religious archi¬ tecture came into its own in the period of the caliphates with the creation of the hypostyle mosque in Iraq and Egypt. Islamic literature is written in four main languages: Arabic, Persian, Turkish, and Urdu. Arabic is of overwhelming importance as the language of the revelation of Islam and of the Qur’an. The Persians used the genres, forms, and rules of Arabic poetry in their own language but elaborated on them. They also devel¬ oped a new genre, the masnavl, composed of a series of rhyming cou¬ plets, which they employed for epic poetry. Persian literature in turn influenced both Urdu and Turkish literature, especially with regard to vocabulary and metres. In the realm of popular literature, the best-known work is The Arabian Nights’ Entertainment, a rich collection of fairy tales from different parts of the Muslim world. Islamic music is monophonic, devoid of harmony, and characterized by distinctive systems of rhythms and melodies, extensive ornamentation of the single melodic line, and virtuoso improvisation. It is usually performed by a small ensemble—a singer and several instrumentalists who alternate solo vocal and instru¬ mental passages. While the theatre has not flourished as a major art under Islam—indeed, conservative Muslims have consistently disapproved of the theatre—there are traditions of folk dance, dance as an entertainment spectacle, and dance as an art form in most Islamic countries. One note¬ worthy form of devotional dance is that of the dervish. Popular traditions such as mime and shadow-puppet shows have also have persisted, and live popular drama has a strong tradition in Persia, where passion plays took root. See also hypostyle hall; Mozarabic art.

Islamic calendar See Muslim calendar

Islamic caste Any one of several units of social stratification among Muslims in India and Pakistan. Their development can be traced to the caste system of Hinduism and the tendency of Muslim converts from Hinduism to maintain social differences. The highest status is reserved for Muslim Arab immigrants, called ashraf. This level is itself divided into subgroups. The highest subgroup claims descent from Muhammad through his daughter, Fatima. The non-ashraf Muslim castes consist of three levels: converts from high Hindu castes, artisan castes, and the UNTOUCHABLES.

Islamic law See Sharia

Islamic philosophy See Arabic philosophy

Islamic Resistance Movement See Hamas

Islamic Salvation Front French Front Islamique du Salut (FIS) Algerian Islamist political party. Known best by its French acro¬ nym, the organization was founded in 1989 by Ali Belhadj and Abbasi al-Madani. The party won a majority of the seats contested in local elec¬ tions in 1990 and most of the seats in the National Assembly in the first round of balloting in 1991. The government canceled the second round, however, and arrested many of the group’s leaders. The FIS and more extreme Islamist groups afterward waged a protracted guerrilla war, in which atrocities by both sides were alleged to have occured. The group was blamed for the assassination of Pres. Mohamed Boudiaf, but no clear proof was ever found. See also Armed Islamic Group; Liamine Zeroual.

island Any area of land smaller than a continent and entirely surrounded by water. Islands may occur in oceans, seas, lakes, or rivers. A group of

964 I island arc ► isomerism

islands is called an archipelago. Continental islands are simply unsub¬ merged parts of a continental mass that are entirely surrounded by water; Greenland, the world’s largest island, is of the continental type. Oceanic islands are produced by volcanic activity, when lava accumulates to enor¬ mous thickness until it finally protrudes above the ocean surface. The piles of lava that form Hawaii rise as high as 32,000 ft (9,700 m) above the ocean floor.

island arc Long, curved chain of oceanic islands associated with intense volcanic and seismic activity and mountain-building processes. Examples include the Aleutian-Alaska Arc and the Kuril-Kamchatka Arc. Most island arcs consist of two parallel rows of islands. The inner row is a string of volcanoes, and the outer row is made up of nonvolcanic islands. In the case of single arcs, many of the islands are volcanically active. An island arc typically has a landmass or a partially enclosed, unusually shallow sea on its concave side. Along the convex side there usually exists a long, narrow deep-sea trench.

Islands, Bay of Inlet, South Pacific Ocean, on the northeastern coast of North Island, New Zealand. The bay was formed when the sea flooded an old river valley system. It has a 500-mi (800-km) shoreline and about 150 islands. It opens to the ocean through a passage between Brett Cape and Wiwiki Cape. The first European to enter the bay was Capt. James Cook in 1769. The bay was the site of the 1840 signing of the Treaty of Waitangi between Britain and native Maori. It is now a popular resort area.

Islas Baleares See Balearic Islands Isle of Man See Isle of Man Isle of Wight See Isle of Wight

Isle Royale National Park Island national park located in northwest¬ ern Lake Superior, northwestern Michigan, U.S. Established in 1931, it has an area of 571,790 acres (231,575 hectares) and includes Isle Royale, the largest island in Lake Superior, measuring 45 mi (72 km) long and 9 mi (14 km) across. Its forested wilderness, with streams and inland lakes, hosts more than 200 species of birds. Travel is possible only on foot or by canoe, and ferry service is available from mainland Michigan and Minnesota.

islets of Langerhans See islets of Iangerhans

Isma'Il \is-'ma-,el\ I (b. July 17, 1487, Ardabll, Azer.—d. May 23, 1524, Ardabll, Safavid Iran) Shah of Iran (1501-24) and founder of the Safavid dynasty. Bom into a Shl'ite family with close ties to the Sunnite Sufi tra¬ dition, he became head of a Shl'ite military force, the Kizilbash, at age 14. He captured Tabriz in 1501 and proclaimed himself shah of Iran, bringing the whole country and portions of modern-day Iraq under his control. In 1510 his troops defeated the Sunnite Uzbeks. His proclama¬ tion of Shl'ism as the official creed prompted the staunchly Sunnite sul¬ tan of the Ottoman Empire to order an invasion of Iran in 1514. Isma'Il lost the Battle of Chaldiran, but mutiny among the Ottoman troops forced their withdrawal. The conflict between the Safavids and their Sunnite neigh¬ bours continued for over a century.

IsmaTl Pasha 'us-'ma-.el-pa-'shaV (b. Dec. 31, 1830, Cairo, Egypt—d. March 2, 1895, Constantinople, Ottoman Empire) Viceroy of Egypt (1863-79) under the Ottoman Empire. After an education in Paris and dip¬ lomatic missions in other parts of Europe, he was appointed viceroy and became involved with work on the Suez Canal (1859-69). His plan to unify the Nile valley by creating a new southern Egyptian province in the Sudan failed. The sultan dismissed him because of his fiscal mismanage¬ ment; the enormous debt he brought on the country led the British to occupy Egypt in 1882.

IsmaTl? \,is-ma-'e-le\ Member of a sect of the ShCite branch of Islam. It came into existence after the death of the sixth imam, Ja'far ibn Muhammad, in 765. His son Isma'Il was accepted as successor only by a minority, who became known as Isma'IlItes. Their doctrine, formulated in the late 8th and early 9th century, made a distinction between ordinary Muslim believ¬ ers and the elect, who shared a secret wisdom. The Qaramitah subsect was popular in Iraq, Yemen, and Bahrain in the 9th—11th centuries, and the Fatimid subsect conquered Egypt in 969 and established the Fajimid dynasty. A subgroup of the Fatimids was the Nizarls, who gained control of fortresses in Iran and Syria in the late 11th century and were known as Assassins. The major Nizarl line survived into modem times under the leadership of the Aga Khan, moving from Iran to India in 1840. The Druze separated from the Isma'IlIs early in the 11th century and formed a closed society of their own.

Ismay Viz-ma\ (of Wormington), Hastings Lionel Ismay, Baron (b. June 21, 1887, Naini Tal, India—d. Dec. 17, 1965, Broadway, Worcestershire, Eng.) British soldier. A career army officer, he served in India and Africa. As Winston Churchill’s chief of staff (1940-46) and closest military adviser, he participated in most major policy decisions of the Allied powers during World War II, particularly in the decision to make Germany the Allies’ first-priority target and in planning for the invasion of France in 1944. After the war he served as secretary-general of NATO (1952-57).

isnad \is-‘nad\ In Islam, a list of authorities who have transmitted accounts of the teachings or actions of Muhammad, one of the Companions of the Prophet, or of a later authority. Each of these accounts, known as Hadith, includes an isnad that gives the chain of authorities by which it has been handed down, using the form, “It has been related to me by A on the authority of B on the authority of C on the authority of D that Muhammad said....” See also 'ilm al-hadith.

ISO See International Organization for Standardization

isobaric spin See isospin

Isocrates \I-'sa-kr9-,tez\ (b. 436, Athens—d. 338 bc, Athens) Athenian author, rhetorician, and teacher. His school, unlike Plato’s more philo¬ sophical Academy, provided an education for the practical needs of soci¬ ety; it was given over almost entirely to rhetoric. He promoted Greek political unity and cultural superiority based on monarchy and advocated a unified Greek attack on Persia under Philip II of Macedonia to secure unity and peace in Greece. When Greece lost its independence after the Battle of Chaeronea, Isocrates, in despair, starved himself to death.

isolationism National policy of avoiding political or economic entanglements with other countries. Isolationism has been a recurrent theme in U.S. history. It was given expression in the Farewell Address of Pres. George Washington and in the early 19th-century Monroe Doctrine. The term is most often applied to the political atmosphere in the U.S. in the 1930s. The failure of Pres. Woodrow Wilson’s internationalism, lib¬ eral opposition to war as an instrument of policy, and the rigours of the Great Depression were among the reasons for Americans’ reluctance to concern themselves with the growth of fascism in Europe. The Johnson Act (1934) and the Neutrality acts (1935) effectively prevented economic or military aid to any country involved in the European disputes that were to escalate into World War II. U.S. isolationism encouraged the British in their policy of appeasement and contributed to French paralysis in the face of the growing threat posed by Nazi Germany. See also neutrality.

Isole Eolie See Eolie Islands

isoleucine \ 1 I-so- , lii- l sen\ One of the essential amino acids, present in most common proteins. It was first isolated in 1904 from fibrin, a protein involved in coagulation. It is used in medicine and biochemical research and as a nutritional supplement.

isomer Vl-so-morX One of two or more substances with identical molecu¬ lar formulas but different configurations, differing only in the arrangement of their component atoms. It usually refers to stereoisomers (rather than constitutional isomers or tautomers; see isomerism, tautomerism), of which there are two types. Optical isomers, or enantiomers (see optical activity), occur in mirror-image pairs. Geometric isomers are often the result of rigidity in the molecular structure; in organic compounds, this is usually due to a double bond (see bonding) or a ring structure. In the case of a double bond between two carbon atoms, if each has two other groups bonded to it and all are rigidly in the same plane, the corresponding groups can be on the same side (cis) of the C=C bond or across the C=C bond (trans) from each other. An analogous distinction can be made for ring structures that are all in a plane, between isomers whose substituent groups are on the same side and isomers whose substituent groups are on both sides of the plane. Diastereomers that are not enantiomers also fall into this category. Most cis-trans isomers are organic compounds.

isomerism U-'sa-mo-.ri-zonA Existence of sets of two or more sub¬ stances with identical molecular formulas (see chemical formula) but dif¬ ferent configurations and hence different properties. Jons Jacob Berzelius was the first to recognize and name it (1830). In constitutional (structural) isomerism, the molecular formula and molecular weight of the substances are the same, but their bonding differs. For example, C 2 H 6 0 is the molecu¬ lar formula for both ethanol (CH 3 CH 2 OH) and methyl ether (CH 3 OCH 3 ). Constitutional isomers that can be readily converted from one to another

Isonzo ► Israel I 965

are called tautomers (see tautomerism). In stereoisomerism, substances with the same atoms are bonded in the same ways but differ in their three- dimensional configurations. See also isomer.

Isonzo \e-'zont-s6\, Battles of the (1915-17) Twelve battles along the Isonzo River on the eastern sector of the Italian front in World War I. The Isonzo River, running just inside Austria, is flanked by rugged peaks that the Austrians had fortified before Italy’s entry into the war in 1915. Luigi Cadoma (1850-1928) led all the attacks against Austria, but the Ital¬ ians could not penetrate the formidable natural barriers. Finally they struck with 51 divisions and dislodged the Austrians, but the Germans sent reinforcements and took the offensive, ending in the Battle of Caporetto.

isoprenoid Vj-so-'pre-.noidV or terpene Class of organic compounds made up of two or more structural units derived from isoprene. Isoprene is a five-carbon hydrocarbon with a branched-chain structure, two double bonds (see bonding), and the molecular formula C 5 H 8 . In isoprenoids, isoprene units (with one or neither of their double bonds) are linked into larger molecules having from two to thousands of five-carbon units that can take the form of both linear structures and rings. Many of these mol¬ ecules play a wide variety of roles in plant and animal physiological pro¬ cesses and as intermediates in the biological synthesis of other important molecules. They contribute greatly to the flavours and fragrances of essen¬ tial oils and other plant-derived substances. Geraniol (a contributor to rose perfumes; from geranium oil), menthol (from peppermint oil), citral (from lemongrass oil), limonene (from lemon and orange oils), pinene (from turpentine), and camphor each have two isoprene units. Examples with more units include phytol, a precursor of chlorophyll; squalene, the pre¬ cursor of cholesterol and other steroids; lycopene, the red pigment in tomatoes and an important phytochemical; and carotene, the pigment in carrots and a precursor of vitamin A. Natural rubber and the related gutta¬ percha are polyisoprenes comprising many thousands of isoprene units.

isospin Vl-sd-,spin\ or isobaric spin or isotopic spin Property characteristic of families of related subatomic particles differing mainly in the values of their electric charge. The families are known as isospin mul- tiplets. The components of atomic nuclei, the neutron and the proton, form an isospin doublet since they differ only in electric charge and subsidiary properties. They are considered different versions of the same object, called a nucleon. The isospin of a nucleon has a value of Vi.

isostasy \I-'sas-t3-se\ Theory describing the mass balance in the Earth’s crust, which treats all large portions of the crust as though they were floating on a denser underlying layer, about 70 mi (110 km) below the surface. In this theory, a mass above sea level is supported below sea level, so high mountains must be regions where the crust is very thick, with deep roots extending into the mantle. This is analogous to an iceberg floating on water, in which the greater part of the iceberg is under water.

isotope Vl-s3-,top\ One of two or more species of atoms of a chemical element having nuclei with the same number of protons but different num¬ bers of neutrons. They have the same atomic number and hence nearly identical chemical behaviour but different atomic MASSes. Most elements found in nature are mixtures of several isotopes; tin, for example, has 10 isotopes. In most cases, only stable isotopes of elements are found in nature. The radioactive forms break down spontaneously into different elements (see radioactivity). Isotopes of all elements heavier than bismuth are radioactive; some occur naturally because they have long half-lives.

Isozaki \,e-so-'za-ke\ A rata (b. July 23, 1931, Oita, Kyushu, Japan) Japanese avant-garde architect. He studied at the University of Tokyo and opened his own studio in 1963. His first notable building is the Oita Pre- fectural Library (1966), which shows the influence of the Metabolist school. In his later works, which often synthesize Eastern and Western elements, he used bold geometric forms and frequently made historical allusions. Among his innovative structures are the Los Angeles Museum of Contemporary Art (1986) and Art Tower (1990) in Mito, Japan.

ISP See Internet service provider

Israel officially State of Israel Country, Middle East, at the eastern end of the Mediterranean Sea. Area: 8,367 sq mi (21,671 sq km). Popu¬ lation (2005 est.): 6,681,000 (includes population of Golan Heights and east Jerusalem; excludes population of the West Bank). Capital: Jerusalem. Jews constitute some four-fifths of the population and Arabs about one- fifth. Languages: Hebrew, Arabic (both official). Religions: Judaism; also Islam, Christianity. Currency: new Israeli sheqel (NIS). Israel can be divided into four major regions: the Mediterranean coastal plain in the

” 136 °

--UN Forces deployment a Shemona

SYRIA

Mount Carmel 1,789 ft.

MEDITERRANEAN

SEA

Note:

Final Status of Gaza Strip and West Bank to be determined by Israel and the Palestinian Authority

Tel Aviv-Yafo # ...

BatYam^Hol

Rehovot*

Ashdod •

Ashqelon # b S heme;

GAZA •„ Hebron

STRIP GaZ jUDJ?E*-^"' s ' Beers'

Nir Yizh

EGYPT

SINAI

PENINSULA

2002 Encyclopaedia Britannica, Inc.

JORDAN

west; a hill region extending from the northern border into central Israel; the Great Rift Valley, containing the Jordan River, in the east; and the arid Negev, occu¬ pying nearly the entire southern half of the

country. Its major drainage system is the interior basin formed by the Jor¬ dan River; Lake Tiberias (Sea of Galilee) provides water to much of the country’s agricultural land. Israel has a mixed economy based largely on services and manufacturing; exports include machinery and electronics, diamonds, chemicals, citrus fruits, vegetables, and textiles. Its population is nine-tenths urban and is concentrated largely in the Mediterranean coastal plain and around Jerusalem. It is a republic with one legislative house, the Knesset; its chief of state is the president, and the head of gov¬ ernment is the prime minister. The record of human habitation in Israel (see Palestine) dates to the Paleolithic Period. Efforts by Jews to establish a national state there began in the late 19th century. Britain supported Zionism and in 1923 assumed political responsibility for what was then called Palestine. Migration of Jews to Palestine, which increased during the period of Nazi persecution, led to deteriorating relations with Arabs. In 1947 the UN voted to partition the region into separate Jewish and Arab states. The State of Israel was proclaimed in 1948, and Egypt, Transjor¬ dan (later Jordan), Syria, Lebanon, and Iraq immediately declared war on it. Israel won that war (see Arab-Israeli wars) as well as the 1967 Six-Day War, in which it occupied the West Bank, Gaza Strip, Golan Heights, and east Jerusalem. (Subsequent claims of Jerusalem as Israel’s capital have not received wide international recognition.) Another war with its Arab neighbours followed in 1973, but the Camp David Accords led to a peace treaty between Israel and Egypt in 1979. Israel invaded Lebanon in 1982 to expel the Palestine Liberation Organization (PLO) from that country, and in late 1987 an uprising broke out among Palestinians of the occupied ter¬ ritories of the West Bank and Gaza Strip (see intifadah). Peace negotia¬ tions between Israel and the Arab states and Palestinians began in 1991. Israel and the PLO agreed in 1993 to a five-year plan to extend self- government to the Palestinians of the occupied territories. Israel signed a peace treaty with Jordan in 1994. Israeli soldiers and a Lebanese militia, Hezbollah, clashed throughout the 1990s. Israeli troops withdrew from Lebanon in 2000, and negotiations between Israel and the Palestinians broke down amid violence that claimed hundreds of lives. In an effort to stem the fighting, Israel in 2005 withdrew its soldiers and settlers from parts of the West Bank and from all of the Gaza Strip, which came under Palestinian control.

Israel, tribes of In the Bible, the 12 clans of the ancient Hebrew people, which were named for the sons of Jacob (Reuben, Simeon, Levi, Judah, Issachar, Zebulun, Joseph, Benjamin, Gad, Asher, Dan, and Naphtali) and his wives, Leah and Rachel, and concubines, Bilhah and Zilpah. The tribe

966 I Israel Labour Party ► Italian Liberal Party

of Levi did not receive land in the settlement of Canaan but instead was given the priestly office. To maintain the traditional number of 12 tribes, the line of Joseph was divided into the tribes of Ephraim and Manasseh. In Israel’s later history, the tribes of Judah and Benjamin formed a south¬ ern kingdom called Judah with its capital at Jerusalem, while the 10 north¬ ern tribes formed the kingdom of Israel. After being conquered by Assyria in 721 bc, the northern tribes were exiled from the kingdom and were assimilated by other peoples. Disappearing from history, they became known as the 10 lost tribes of Israel and remained part of Jewish folklore and eschatological beliefs. The tribes of Judah and Benjamin survived until Nebuchadrezzar’s conquest of Judah in 586 bc, when many from the kingdom were exiled to Babylon.

Israel Labour Parly Israeli political party founded in 1968 as the union of three socialist-labour parties. The Israel Labour Party and its predecessors led governing coalitions uninterruptedly from 1948 to 1977; since 1977 it has competed with the conservative Likud party. Its princi¬ pal figures have included David Ben-Gurion, Moshe Dayan, Golda Meir, Shimon Peres, and Yitzhak Rabin.

Israeli, Isaac ben Solomon or Isaac the Elder (b. 832/855, Egypt—d. 932/955, Al-Qayrawan, Tun.) Egyptian Jewish physician and philosopher. He began his medical career as an oculist in Cairo and later became court physician to al-Mahdl, founder of the Fajimid dynasty in northern Africa. He wrote several medical treatises in Arabic that were later translated into Latin and circulated in Europe. Schooled in Classical learning, he wrote philosophical works, including his Book of Definitions, which discusses Aristotle’s four types of inquiry and then provides defi¬ nitions of wisdom, intellect, soul, nature, love, and time. His interpreta¬ tion of eschatological matters in light of Neoplatonic mysticism was very influential for later Jewish philosophers.

Israeli law Legal practices and institutions of modem Israel. The ancient people of Israel created the law of the Torah and the Mishna (the latter was later incorporated into the Talmud). Contemporary Israeli law reflects a dual legal heritage: it is based on historic Jewish law and the laws of countries in which the Jews had for generations been living. It is derived from Ottoman and British legislation and precedents, religious court opinion, and Israeli parliamentary enactments. Courts are composed of professional judges only; juries are not used. Jewish law as such con¬ tinues to be applied by the rabbinical courts within their jurisdiction in matters of personal status; it is applied also by the civil courts when called upon to deal with such matters concerning Jews.

Israelite In early Jewish history, a member of the 12 tribes of Israel. After the establishment (930 bc) of two Jewish kingdoms (Israel and Judah) in Palestine, only the ten northern tribes constituting the kingdom of Israel were known as Israelites. When Israel was conquered by the Assyrians (721 bc), its population was absorbed by other peoples, and the term Israelite came to refer to those who were still distinctively Jewish— the descendants of the kingdom of Judah. In liturgical usage, an Israelite is a Jew who is neither a cohen nor a Levite (see Levi).