An effector organ found in six different groups of fishes; output is an electric pulse. Voltages large enough to aid in prey capture or predator deterrence are produced by various strongly electric fishes. These include the electric eel (Electrophorus electricus) from South America; the electric catfish (Malapterurus electricus) from Africa; the family of electric rays, […]

Conventional fuels such as gasoline and diesel are gradually being replaced by alternative fuels such as gaseous fuels (natural gas and propane), alcohol (methanol and ethanol), and hydrogen. Conventional fuels can also be modified to a reformulated gasoline to help reduce toxic emissions. Technological advances in the automotive industry (such as in fuel cells and […]

A mathematical entity consisting of a set of values (the carrier set) and a collection of operations that manipulate them. For example, the Integer abstract data type consists of a carrier set containing the positive and negative whole numbers and 0, and a collection of operations manipulating these values, such as addition, subtraction, multiplication, equality […]

A term used synonymously with mod ern algebra and general algebra to describe the type of algebra which has been developed since the mid-1920s and has become a basic idiom of contemporary mathematics. In contrast with the earlier algebra, which was highly computational and was con fined to the study of specific systems generally based […]

An order of monocotyledonous angiosperms composed of a single genus, Acorus (sweet flag or sweet cala mus), with two species widespread in the Northern Hemisphere. Formerly, Acorus was included in the amid family, Araceae, but several lines of evidence, including deoxyribonucleic acid (DNA) sequences, have firmly established it as the first-branching lineage of the monocotyledons. […]

Absorption (biology): The net movement (transport) of water and solutes from outside an organism to its interior. The unidirectional flow of materials into an animal from the environment generally takes place across the alimentary tract, the lungs, or the skin, and in each location a specific cell […]