metropolitan area network (MAN): see local area network.

local area network (LAN), a computer network dedicated to sharing data among several single-user workstations or personal computers, each of which is called a node. A LAN can have from two to several hundred such nodes, each separated by distances of several feet to as much as a mile, and should be distinguished from connections among computers over public carriers, such as telephone circuits, that are used for other purposes. Because of the relatively small areas involved, the nodes in a LAN can be connected by special high-data-rate cables. A metropolitan area network (MAN) is defined as being restricted to a larger area (maximum distances of 50-60 miles) than a LAN but one still small enough so that dedicated links (such as microwave links) can be used. See also modem.

catchment area or drainage basin, area drained by a stream or other body of water. The limits of a given catchment area are the heights of land—often called drainage divides, or watersheds—separating it from neighboring drainage systems. The amount of water reaching the river, reservoir, or lake from its catchment area depends on the size of the area, the amount of precipitation, and the loss through evaporation (determined by temperature, winds, and other factors and varying with the season) and through absorption by the earth or by vegetation; absorption is greater when the soil or rock is permeable than when it is impermeable. A permeable layer over an impermeable layer may act as a natural reservoir, supplying the river or lake in very dry seasons. The catchment area is one of the primary considerations in the planning of a reservoir for water-supply purposes.

area, measure of the size of a surface region, usually expressed in units that are the square of linear units, e.g., square feet or square meters. In elementary geometry, formulas for the areas of the simple plane figures and the surface areas of simple solids are derived from the linear dimensions of these figures. Examples are given in the table entitled Formulas for Various Areas. The areas of irregular figures, plane or solid, can be computed or closely approximated by the use of integral calculus.

Yamalo-Nenets Autonomous Area, administrative division (1995 pop. 479,700), c.290,000 sq mi (751,000 sq km), NW Siberian Russia, on both sides of the Gulf of Ob and including the Yamal peninsula. The area has frozen ground (permafrost) and tundra, forest tundra, and taiga vegetation. There are deposits of iron ore, coal, natural gas, and peat in the region. Exploration of the huge oil and gas fields on the Yamal peninsula has damaged reindeer habitat and destroyed fishing, threatening the longstanding self-sufficiency of the Nenets people, whose traditional occupations have been reindeer raising, fishing, and fur trapping. Salekhard is the capital and Novy Port is a regular supply point on the Northern Sea route. The population consists of Russians, Nenets, Khanty, and Komi. The area was organized as a special area in 1930. The Soviet government maintained forced labor camps in the area.

Whiskeytown-Shasta-Trinity National Recreation Area: see National Parks and Monuments (table).

Ust-Ordyn-Buryat Autonomous Area, former administrative division, 9,000 sq mi (24,000 sq km), S Siberian Russia, in the Irkutsk region. Formed in 1937, it stretched from the Baykal Mts. to the Angara river. The capital was Ust-Ordynsk. Buryats, Buddhist descendants of the Mongols, made up 36% of the population; Russians most of the rest. Formed originally as a national area, it became an autonomous area in 1977. In 2008 the autonomous area was merged into the Irkutsk region.

Santa Monica Mountains National Recreation Area: see National Parks and Monuments (table).

Ross Lake National Recreation Area: see National Parks and Monuments (table).

Nenets Autonomous Area, administrative division (1990 est. pop. 55,000), 68,224 sq mi (176,700 sq km), extreme NE European Russia. Formed in 1929, the area forms the northern part of Arkhangelsk oblast and extends along the tundra coast of the Barents, White, and Kara seas. Naryan-Mar, the capital, is a lumber port on the Pechora River. The area includes the northern section of the Pechora coal basin, with mines at Khalmer-Yu and along the Silova River. Until the discovery of oil and gas fields, reindeer raising, fishing, fur trapping, and seal hunting were the chief occupations. Fish canning, sawmilling, and hide processing are also important to the area. Many of the formerly nomadic Nenets live in agricultural settlements. Russians make up a majority (66%) of the population, while the Nenets have shrunk to 12% of the population. The Nenets, previously known as Samoyedes, speak a Finno-Ugric language and are either Orthodox Christians or animists. They were first mentioned in the 11th cent., and became tributaries of the grand duchy of Moscow at the end of the 15th cent. In 1977 the area's political status was changed from a national area to an autonomous area. In the 1990s there have been demands for an increase in the area's share of oil royalties, as well as talk of secession from the oblast.

Mississippi National River and Recreation Area: see National Parks and Monuments (table).

Lake Roosevelt National Recreation Area: see National Parks and Monuments (table).

Lake Meredith National Recreation Area: see National Parks and Monuments (table).

Lake Mead National Recreation Area: see National Parks and Monuments (table).

Lake Chelan National Recreation Area: see National Parks and Monuments (table).

Koryak Autonomous Area: see Kamchatka, peninsula, Russia.

Komi-Permyak Autonomous Area, former administrative division, 12,664 sq mi (32,800 sq km), E central European Russia, in the basin of the upper Kama River. The capital was Kulymkar. The Komi and the Komi-Permyaks, both Finno-Ugric peoples, made up around 60% of the population; the rest were mostly Russians. The area was established in 1925, given autonomous status in 1977, and unified with the surrounding Perm region to form Perm Territory in 2005.

Khanty-Mansi Autonomous Area, administrative division (1995 pop. 1,326,200), 201,969 sq mi (523,100 sq km), W Siberian Russia. Khanty-Mansisk is the capital. The region, mostly forest and swamp with numerous lakes and peat bogs, is drained by the lower Irtysh and the Ob rivers, which are also important transportation arteries. It has seen spectacular population growth since 1970, mostly due to expansion of natural gas exploitation; the largest concentrations of people are in the Ob and Irtysh valleys. Lumbering, fishing, fur farming and trading, and reindeer breeding are the area's chief occupations. Some grain and vegetables are grown in the south, and fish processing is carried on. Oil and natural gas production is increasingly important, notably at Berezovo, Surgut, and Nizhnevartovsk, where large natural gas fields have been developed. Lumbering is hampered by the area's great distance from markets. Russians comprise two thirds of the area's population, and there are small minorities of Khanty (Ostyaks) and Mansi (Voguls), both of whom belong to the Finno-Ugric linguistic family. Some Komi and Nenets also inhabit the region. The Khanty, who were under the control of the Siberian Tatars, opposed Russian conquest and rule from the 16th through the 18th cent. The Mansi have been in the area since the 11th cent.; they, too, resisted Muscovite domination. The area, formed in 1930, was known until 1940 as the Ostyak-Vogul National Area. In 1977 it was made an autonomous area.

Golden Gate National Recreation Area, Calif.: see National Parks and Monuments (table).

Gauley River National Recreation Area: see National Parks and Monuments (table).

Gateway National Recreation Area, N.Y.-N.J.: see National Parks and Monuments (table).

Evenki Autonomous Area, former administrative division (1992 pop. 25,100), 287,645 sq mi (745,000 sq km), N central Siberian Russia, in the Central Siberian Uplands. It became a national area in 1930 and an autonomous area in 1977, but was merged into Krasnoyarsk Territory, of which it forms the entire central section, in 2007. The village of Tura was the capital. Russians, Evenki, and Yakuts made up the bulk of the autonomous area's population, which was of a very low density.

The Evenki are a Tungus-Manchurian-speaking people of Mongol origin; they are scattered throughout Siberia and number about 24,000. Their religion intermingles Russian Orthodox and Lamaist Buddhist rites with indigenous shamanism. In prehistoric times, the Evenki lived around Lake Baykal. They were mostly conquered by Russia in the 17th cent. Under the Soviet government, the Evenki largely abandoned their nomadic existence for a more sedentary life.

European Economic Area: see European Free Trade Association; European Union.

Driftless Area, c.13,000 sq mi (33,670 sq km), largely in SW Wis. but extending into SE Minn., NE Iowa, and NW Ill. The continental glacier which covered most surrounding regions did not touch this area, which abounds in caves and sinkholes and has residual, well-drained soil. Because it was an important lead-mining region, the federal government prohibited farming in the Driftless Area until the 1840s. It was then settled by European immigrants.

Curecanti National Recreation Area: see National Parks and Monuments (table).

Chickasaw National Recreation Area: see National Parks and Monuments (table).

Chattahoochee River National Recreation Area: see National Parks and Monuments (table).

Cane River Creole National Historical Park and Heritage Area: see National Parks and Monuments (table).

Boston Harbor Islands National Recreation Area: see National Parks and Monuments (table).

Big South Fork National River and Recreation Area: see National Parks and Monuments (table).

Amistad National Recreation Area: see National Parks and Monuments (table).

Agin-Buryat Autonomous Area or Aga Buryat, former administrative division, S Siberian Russia, in what is now the Transbaykal Territory. Aginskoye was the capital. Formed in 1937, the area followed the Onon River. Buryats, Buddhist descendants of the Mongols, made up about 54% of the area's population. In 2008 the autonomous area was merged with the surrounding Chita region to form the Transbaykal Territory.

Contact between peoples with different cultures, usually leading to change in one or both systems. Forms of culture contact traditionally include acculturation, assimilation, and amalgamation. Acculturation is the process of change in material culture, traditional practices, and beliefs that occurs when one group interferes in the cultural system of another, directly or indirectly challenging the latter to adapt to the ways of the former. Such change has characterized most political conquests and expansions over the centuries. Assimilation is the process whereby individuals or groups of differing ethnicity are absorbed into the dominant culture of a society—though not always completely. In the U.S. millions of European immigrants became assimilated within two or three generations; factors included the upheaval of overseas relocation, the influences of the public school system, and other forces in American life. Amalgamation (or hybridization) occurs when a society becomes ethnically mixed in a way that represents a synthesis rather than the elimination or absorption of one group by another. In Mexico, for example, Spanish and Indian cultures became increasingly amalgamated over centuries of contact.

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