autumn crocus Any plant of the genus Colchicum (lily family), some¬ times called meadow saffron, comprising about 30 species of herbaceous plants native to Eurasia. The stemless, crocuslike flowers bloom in autumn. Several species are cultivated as ornamentals for their pink,
white, or bluish-purple tubelike flowers, especially C. autumnale, C. born- muelleri, and C. speciosum. The swollen underground stem of C. autum¬ nale contains colchicine, a substance used to relieve the pain of gout.
Auvergne \o-'vern y \ Region (pop., 1999: 1,308,878), south-central France. It was once inhabited by the Arverni, a Gallic people led by Ver- cingetorix and defeated by Julius Caesar. It was yielded to the Visigoths in ad 475 and conquered by the Franks under Clovis I in 507. It became part of Aquitaine, and in the 8th century it was made a countship. It passed to the Bourbons in 1416 and to France c. 1530.
auxiliary In grammar, a verb that is subordinate to the main lexical verb in a clause. Auxiliaries can convey distinctions of tense, aspect, mood, person, and number. In Germanic languages such as English and Romance languages such as French, an auxiliary verb occurs with the main verb in the form of an infinitive or participle.
auxin Any of a group of hormones that regulate plant growth, particu¬ larly by stimulating cell elongation in stems and inhibiting it in roots. Auxins influence the growth of stems toward light (phototropism) and against the force of gravity (geotropism). Auxins also play a role in cell division and differentiation, fruit development, the formation of roots from cuttings, the inhibition of lateral branching, and leaf fall. The most important naturally occurring auxin is beta-indolylacetic acid.
Ava \'a-va\ Ruined city, Myanmar. The city, located on the Irrawaddy River southwest of Mandalay, was founded in the 14th century by the Shans, who made it their capital. It was destroyed in 1527, but again became the capital in 1634 under the Toungoo dynasty. When Alaung-
Pathways of the autonomic nervous system. Nerve impulses begin in motor neurons in the brain or spinal cord. Each motor neuron connects with a second motor neu¬ ron outside the central nervous system to carry the impulse to the glands and smooth muscles. In the sympathetic nervous system, these second motor neurons are found in ganglia (masses of neurons) along either side of the spinal cord. In the parasympathetic nervous system, ganglia are located closer to, or sometimes within, the target organs. Some ganglia form large clusters called plexuses. Pregan¬ glionic fibres of the sympathetic system emerge along the thoracic (T) and first three lumbar (L) segments of the spinal cord. Fibres of the parasympathetic system origi¬ nating in the brainstem arise from the third, seventh, ninth, and tenth cranial nerves; other parasympathetic fibres emerge from the second, third, and fourth sac¬ ral (S) segments of the spinal cord.
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138 I avalanche ► Avesta
paya founded the Konbaung dynasty in the 18th century, Ava served as its capital for a time, and even after the dynasty built Amarapura and Mandalay, its seat was often referred to as the “Court of Ava.”
avalanche Large mass of material, such as snow or rock debris, that moves rapidly down a mountain slope, sweeping everything in its path. Avalanches begin when a mass of material overcomes the frictional resis¬ tance of the sloping surface, often after the material’s foundation has been weakened by rains or the snow has been partially melted by a warm, dry wind. Other weather conditions that can lead to avalanches are heavy snowfall and high winds. A common method of avalanche control con¬ sists of detonating explosives in the upper reaches of avalanche zones, which intentionally causes the snow to slide before accumulations have become very great.
Avalokitesvara \ 1 3-v9- 1 lo-ki-'tash-v9-r9\ Chinese Guanyin \'gwan-'yin\ Japanese Kannon Vkan-'n6n\ Bodhisattva of infinite compassion and mercy, the most popular of Mahayana Buddhist dei¬ ties. He is the earthly manifestation of Amitabha, guarding the world between the departure of the histori¬ cal Buddha, Gautama, and the appearance of the future Buddha,
Maitreya. He is the creator of the fourth world, the actual living uni¬ verse. In China and Japan his gender became ambiguous; he is sometimes called a goddess. For Pure Land Bud¬ dhists, he forms a ruling triad with Amitabha and the bodhisattva Mahasthamaprapta. In Tibetan Bud¬ dhism, he is thought to be reincar¬ nated in each Dalai Iama in order to preserve buddha-teaching.
Avalon Island to which Britain’s legendary King Arthur was taken after he was mortally wounded in his last battle. First described by Geof¬ frey of Monmouth, it was said to be ruled by Morgan le Fay and her eight sisters, all of whom were skilled in the healing arts. Legend held that when Arthur was healed he would return to rule Britain. The tale may have originated in Celtic myths of an elysium for fallen heros. Avalon has sometimes been identified with Glas¬ tonbury in Somerset.
Avanti Historic kingdom, north-central India. Located on the overland trade routes between northern and southern India, it lay within present- day Madhya Pradesh. Its capital was at Ujjayini (near present-day Ujjain). It flourished in the 6th^lth centuries bc as one of the great powers of northern India. In the 4th century bc it was conquered and annexed by Candra Gupta Maury a of Magadha. Ujjayini, one of the seven holy cities of Hinduism, was renowned for its beauty and wealth; it also became a centre of early Buddhism and Jainism.
Avar \'a-var\ Any member of a people of undetermined origin who built an empire in eastern Europe between the Adriatic and Baltic seas and the Elbe and Dnieper rivers in the 6th-9th centuries. Mounted nomads, pos¬ sibly from Central Asia, they made the Hungarian plain the centre of their empire, from which they intervened in Germanic tribal wars, helped the Lombards overthrow allies of Byzantium, and nearly succeeded in occu¬ pying Constantinople in 626. They also fought the Merovingians and helped push the Serbs and Croats southward. Avar decline began in the late 7th century and culminated in the destruction of their capital by Charlemagne in 796. In the early 9th century the Avars were fully incor¬ porated in the Carolingian empire.
Avatamsaka-sutra V.o-vo-'tom-so-ko-'su-troN or Garland Sutra
Mahayana Buddhist sutra that explores the teachings of the Buddha Gautama. It speaks of the deeds of the Buddha and the resulting merits that blossom like a garland of flowers. It begins with the Buddha’s Enlighten¬
ment attended by a chorus of bodhisattvas and divine beings. It describes an assembly in the palace of Indra, where the Buddha teaches that all beings have the Buddha nature. Around ad 400 a Chinese translation appeared, Huayan jing, which gave rise in the 6th century to the Huayan sect, which became in Japan the Kegon school. See also Vairocana.
avatar Ya-v9-,tar\ In Hinduism, the incarnation of a deity in human or animal form to counteract an evil in the world. It usually refers to 10 appearances of Vishnu, including an incarnation as the Buddha Gautama and Kalkin (the incarnation yet to come). The doctrine appears in the Bhagavadgita in the words of Lord Krishna to Arjuna: “Whenever there is a decline of righteousness and rise of unrighteousness then I send forth Myself.”
Avebury \'av-bo-re\ Village, Wiltshire, England, lying partly within one of the largest prehistoric sites in Europe. The site occupies 28.5 acres (11.5 hectares) and contains vast megalithic remains, including chalk blocks and sandstone pillars placed in circles. Its date and origin are uncertain. Kennet Avenue, a route into the interior of the great circle, linked Ave¬ bury with a temple 1 mi (1.6 km) away.
Avedon Va-va-.danX, Richard (b. May 15, 1923, New York, N.Y., U.S.—d. Oct. 1, 2004, San Antonio, Texas) U.S. photographer. He began studying photography in the U.S. merchant marine. In 1945 he became a regular contributor to Harper's Bazaar, he later was closely associated with Vogue. Avedon’s fashion photographs are characterized by a strong black-and-white contrast that creates an effect of austere sophistication. In his portraits of celebrities and other sitters, he created a sense of drama by often using a stark, white background and eliciting a frontal, confron¬ tational pose. Many collections of his photographs have been published.