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catalyst
catalyst substance that can cause a change in the rate of a chemical reaction without itself being consumed in the reaction; the changing of the reaction rate by use of a catalyst is called catalysis. Substances that increase the rate of reaction are called positive catalysts or, simply, catalyst...
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infancy
infancy stage of human development lasting from birth to approximately two years of age. The hallmarks of infancy are physical growth, motor development, vocal development, and cognitive and social development.
Physical Growth
The first year is characterized by rapid physical growth. A no...
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Alexander Dubček
Alexander Dubček , 1921-92, Czechoslovakian political leader. A member of the Slovakian national minority, he was active in the Communist underground in World War II and rose in the party hierarchy after the war, becoming head of the Slovakian Communist party and a member of the presidium of th...
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hyperinsulinism
hyperinsulinism presence in the system of an above-normal amount of insulin , the substance secreted by the pancreas and needed by the body to utilize sugar. An increased amount of insulin in the body results in below-normal amounts of sugar in the system, giving rise to such symptoms as headach...
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Khabarovsk
Khabarovsk , city (1989 pop. 601,000), capital of Khabarovsk Territory and the administrative center of the Far East district, Russian Far East , on the Amur River near its junction with the Ussuri. An industrial center and a major transportation point on the Trans-Siberian RR , the city has oil r...
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archangel
archangel , chief angel . They are four to seven in number. Sometimes specific functions are ascribed to them. The four best known in Christian tradition are Michael , Gabriel , Raphael , and Uriel . In early Jewish literature archangels are called "angels of the presence."
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Taliban
Taliban or Taleban , Islamic fundamentalist militia of Afghanistan and later Pakistan, originally consisting mainly of Sunni Pashtun religious students educated and trained in Pakistan. The Taliban emerged as a significant force in Afghanistan in 1994 when they were assigned by Pakistan to prote...
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Kiowa
Kiowa , Native North Americans whose language is thought to form a branch of the Aztec-Tanoan linguistic stock (see Native American languages ). The Kiowa, a nomadic people of the Plains area, had several distinctive traits, including a pictographic calendar and the worship of a stone image, the t...
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galvanometer
galvanometer , instrument used to determine the presence, direction, and strength of an electric current in a conductor. All galvanometers are based upon the discovery by Hans C. Oersted that a magnetic needle is deflected by the presence of an electric current in a nearby conductor. When an elect...
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stalactite and stalagmite
stalactite and stalagmite , mineral forms often found in caves; sometimes collectively called dripstone. A stalactite is an icicle-shaped mass of calcite attached to the roof of a limestone cavern. Groundwater trickling through cracks in the roofs of such caverns contains dissolved calcium bicarbona...
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