Acadia North American possession of France in the 17th—18th century, centred in what is now Nova Scotia. Acadia was probably intended to include the other present Maritime Provinces as well as parts of Maine and Quebec. The first European settlement was founded by Samuel de Cham¬ plain and Pierre du Gast in 1604. The area at times was also claimed by the British and was contested often in the 18th-century colonial wars; in 1713 Nova Scotia came under British rule. In 1755 many French-speaking Acadians were deported by the British because of imminent war with France; several thousand settled in French-ruled Louisiana, where their descendants were known as Cajuns. The event was the theme for Henry W. Longfellow’s Evangeline.
Acadia National Park Preserve on the coast of Maine, U.S. It has an area of 65 sq mi (168 sq km). Originally established as Sieur de Monts National Monument (1916), it became the first national park in the east¬ ern U.S. as Lafayette National Park (1919) and was renamed Acadia in 1929. It consists mainly of a forested area on Mount Desert Island, domi¬ nated by Cadillac Mountain.
Acadia University Privately endowed university in Wolfville, Nova Scotia, Canada. Founded in 1838, it took its current name and status in 1891. It has faculties of arts, professional studies, science, theology, edu¬ cation, and graduate studies. Acadia ranks among the country’s top under¬ graduate institutions.
Acadian orogeny Vs-'ka-de-on-o-'ra-jo-neV Mountain-building event that affected the northern portion of the Appalachian Geosyncune from present-day New York to Newfoundland during the Devonian period. The orogeny was most intense in northern New England. Its origin has been ascribed to the collision of the northeastern portion of the North Ameri¬ can Plate with western Europe. Evidence for the orogeny includes defor¬ mation of pre-Devonian and Devonian rocks.
acanthus \3-'kan-thos\ Any of the more than 2,500 plant species that make up the family Acanthaceae, of the figwort order. Acanthus are found mostly in tropical and subtropical regions. Most are herbaceous plants or shrubs that grow in tropical rainforests; some are climbers (vines) or trees. Acanthus have simple leaves arranged in opposite pairs on the twigs and enlarged cells called cystoliths in streaks or protuberances in the vegeta¬ tive parts. The bisexual flowers are bilaterally symmetrical and usually crowded together in clusters. Individual flowers are enclosed by leaflike bracts, which are often coloured and large. Acanthus are mainly of hor¬ ticultural interest and include some ornamentals.
Acapulco in full Acapulco de Juarez City and port (pop., 2000: 619,253), southwestern Mexico. Situated on a deep semicircular bay, it has the best harbour on Mexico’s Pacific coast. It was discovered by Hernan Cortes in 1531, and a settlement was founded in 1550. Until 1815 it was a main depot for Spanish colonial fleets going to the Far East. It has become a major international resort for tourists attracted by its sce¬ nic beauty, climate, and excellent beaches.
Acarnania V.a-kor-'na-ne-oV District, ancient Greece, bounded by the Ionian Sea, the Ambracian Gulf, and the Achelous River. First settled in the 7th-6th centuries bc, it developed into a federal state by the late 5th century bc; its capital was Stratus. It later came under Athenian, Theban, and Macedonian rule. Part of Acarnania recovered its independence in 231 bc and began an alliance with Philip V of Macedon. Rome overthrew the Macedonian dynasty in 167 bc, and Acarnania survived until Augus¬ tus incorporated many Acamanians into his new city Nicopolis Actia.
acceleration Rate of change of velocity. Acceleration, like velocity, is a vector quantity: it has both magnitude and direction. The velocity of an
object moving on a straight path can change in magnitude only, so its acceleration is the rate of change of its speed. On a curved path, the velocity may or may not change in magnitude, but it will always change in direction, which means that the acceleration of an object moving on a curved path can never be zero. If velocity is stated in metres per second (m/s) and the time interval in seconds (s), then the units of acceleration are metres per second per second (m/s/s, or m/s 2 ). See also centripetal ACCELERATION.
accelerator, particle See particle accelerator
accelerometer \ik- 1 se-b- , ra-m3-t3r\ Instrument that measures accel¬ eration. Because it is difficult to measure acceleration directly, the device measures the force exerted by restraints placed on a reference mass to hold its position fixed in an accelerating body. The output is usually either a varying electrical voltage or displacement of a moving pointer over a fixed scale. Specially designed accelerometers are used in varied applications: control of industrial vibration test equipment, detection of earthquakes (seismographs), and input to navigational and inertial guidance systems.
accent In prosody, a rhythmically significant stress on the syllables of a verse, usually at regular intervals. Though the term is often used inter¬ changeably with stress, some prosodists use accent to mean the empha¬ sis determined by normal language usage and stress to mean emphasis determined by metrical pattern.
acceptance Short-term credit instrument consisting of a written order that requires a buyer to pay a specified sum to the seller at a given date, signed by the buyer as a promise to honor the obligation. Acceptances are often used in export/import transactions: an exporter may require a buyer to sign and return an acceptance, which the exporter can then sell to the bank at a discount, thereby obtaining payment promptly. The buyer then has until the bill’s maturity date to dispose of the goods and pay the promised sum (now owed to the bank). See also bill of exchange; promis¬ sory note.
acclimatization Any of numerous gradual, long-term responses of an individual organism to changes in its environment. The responses are more or less habitual and reversible should conditions revert to an earlier state. These criteria differentiate acclimatization from homeostasis; from growth and development (which cannot be reversed); and from evolution¬ ary adaptation (which occurs in a population over generations). Acclima¬ tization can occur in anticipation of a change and enable organisms to survive conditions beyond their natural experience. Examples include adaptations to seasonal changes and adjustments to changes in altitude.
accordion Portable musical instrument that uses a hand-pumped bel¬ lows and two keyboards to sound free reeds, small metal tongues that vibrate when air flows past them.
The keyboards on either side of the bellows effectively resemble indi¬ vidual reed organs. The right-hand keyboard plays the treble line or lines. Most of the keys on the left- hand (bass) keyboard sound three- note chords; “free-bass” accordions permit the playing of single-note lines. A prototype accordion, using buttons rather than keys, was pat¬ ented in Berlin in 1822 by Friedrich Buschmann (also inventor of the har¬ monica). The instrument gained wide popularity in dance bands and as a folk instrument. See also concertina.
account payable Any amount owed as the result of a purchase of goods or services on a credit basis. Although a firm making a purchase issues no written promise of payment, it enters the amount owed as a cur¬ rent liability in its accounts. Companies often incur this type of short¬ term debt in order to finance their inventories, especially in industries where inventory turnover is rapid. See also account receivable.
account receivable Any amount owed to a business as the result of a purchase of goods or services from it on a credit basis. Although the firm making the sale receives no written promise of payment, it enters the amount due as a current asset in its books. Accounts receivable constitute a major portion of the assets of many companies, and they may even be sold or pledged as collateral to obtain loans. See also account payable; factoring.