Myanmar \'myan-,mar\ or Burma officially Union of Myanmar
Country, Southeast Asia, on the Bay of Bengal and the Andaman Sea. Area: 261,228 sq mi (676,577 sq km). Population (2005 est.): 46,997,000. Capi¬ tals: Yangon (Rangoon)/Pyinmana. Inhabitants are chiefly Burman; oth¬ ers include Chin, Shan, and Karen. Languages: Burmese (official), many
indigenous languages. Religions: Bud¬ dhism, traditional beliefs, Christianity, Islam, Hinduism. Currency: kyat. Myan¬ mar may be divided into five main regions: the northern mountains, the western ranges, the coastal plains, the central lowlands, and the Shan Plateau in the east. Major rivers are the Irrawaddy and the Salween. The tropical cli¬ mate is greatly influenced by the monsoons of southern Asia. Only about one-sixth of this largely mountainous land is arable. It has a centrally planned, developing economy that is largely nationalized and based on agriculture and trade. Rice is the most important crop and principal export; teak is also important. Myanmar is ruled by a military regime; its head of state and government is the chairman of the State Peace and Devel¬ opment Council, assisted by the prime minister. The area was long inhab¬ ited, with the Mon and Pyu states dominant from the 1 st century bc to the 9th century ad. It was united in the 11th century under a Burmese dynasty that was overthrown by the Mongols in the 13th century. The Portuguese, Dutch, and English traded there in the 16th—17th century. The modem Myanmar (Burmese) state was founded in the 18th century by Alaung- paya. Conflict with the British over Assam resulted in a series of wars, and Myanmar fell to the British in 1885. Under British control, it became Burma, a province of India. It was occupied by Japan in World War II and became independent in 1948. The military took power in a coup in 1962 and nationalized major economic sectors. Civilian unrest in the 1980s led to antigovernment rioting that was suppressed by force. In 1990 opposi¬ tion parties won in national elections, but the army continued in control. Trying to negotiate for a freer government amid the unrest, Aung San Suu Kyi was awarded the Nobel Peace Prize in 1991.
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myasthenia gravis V.ml-os-'the-ne-o-'gra-vosV Chronic autoimmune disease causing muscle weakness. Autoantibodies block the response of muscle cells to acetylcholine. Muscles weaken with repeated use but regain
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mycelium ► myrtle I 1319
their strength after rest. The pattern varies, but usually muscles used in eye movements, facial expressions, chewing, swallowing, and respiration are affected first, then neck, trunk, and limb muscles. Severe cases impede breathing. Anticholinesterase drugs stimulate nerve-impulse transmission, and corticosteroids may help. Removal of the thymus has improved severe cases. Remission lasting several years may occur.
mycelium \ml-'se-le-3m\ Mass of branched, tubular filaments (hyphae) of fungi (see fungus) that penetrate soil, wood, and other organic matter. The mycelium makes up the thallus (undifferentiated body) of a typical fungus. The mass may be microscopic in size or developed into visible structures, such as brackets, mushrooms, puffballs, or truffles. The myce¬ lium produces spores, directly or through special fruiting bodies.
Mycenae \ml-'se-ne\ Prehistoric city, northeastern Peloponnese, Greece. A natural rock citadel, it was the legendary capital of Agamemnon. It flourished during the Bronze Age, building the distinctive Mycenaean civi¬ lization. It was at its height in the Aegean c. 1400 bc and declined c. 1100 bc with the invasion of the Dorians from the north. Excavations at Myce¬ nae began in 1840, but the most celebrated discoveries there were those by Heinrich Schliemann c. 1876. Ruins include the Lion Gate, acropolis, granary, and several royal beehive tombs and shaft graves.
Mycenaean \ l ml-s9- , ne-9n\ Any member of a group of warlike Indo- European peoples who entered Greece from the north starting c. 1900 bc and established a Bronze Age culture on the mainland and nearby islands. Their culture was dependent on that of the Minoans of Crete, who for a time politically dominated them. They threw off Minoan control c. 1400 and were dominant in the Aegean until they themselves were over¬ whelmed by the next wave of invaders c. 1150. Mycenae continued to exist as a city-state into the period of Greek dominance, but by the 2nd cen¬ tury ad it was in ruins. Mycenaean myths and legends lived on through oral transmission into later stages of Greek civilization and form the basis of Homeric epic and Greek tragedy. Their language is believed to be the most ancient form of Greek.
mycobacterium \ l mI-ko-bak-'tir-e-3m\ Any of the rod-shaped bacte¬ ria that make up the genus Mycobacterium. The two most important spe¬ cies cause tuberculosis and leprosy in humans; another species causes tuberculosis in both cattle and humans. Some mycobacteria live on decay¬ ing organic matter; others are parasites. Most are found in soil and water in a free-living form or in diseased tissue of animals. Various antibiotics have had some success against mycobacterium infections.
mycology \ml-'ka-l3-je\ Study of fungi (see fungus), including mush¬ rooms and yeasts. Many fungi are useful in medicine and industry. Myco- logical research has led to the development of such antibiotic drugs as penicillin, streptomycin, and tetracycline. Mycology also has important appli¬ cations in the dairy, wine, and baking industries and in the production of dyes and inks. Medical mycology is the study of fungus organisms that cause disease in humans.
mycoplasma V.ml-ko-'plaz-moX Any of the bacteria that make up the genus Mycoplasma. They are among the smallest of bacterial organisms. The cell varies from a spherical or pear shape to that of a slender branched filament. Mycoplasma species are gram-negative (see gram stain) and do not require oxygen. They are colonial microorganisms that lack cell walls. They are parasites of joints and the mucous membranes lining the respi¬ ratory, genital, or digestive tracts of cud-chewing animals, carnivores, rodents, and humans. Toxic by-products excreted by the bacteria accu¬ mulate in the host’s tissues, causing damage. One species causes a wide¬ spread but rarely fatal pneumonia in humans.
mycorrhiza V.mi-ko-'ri-zoN Product of close association between the branched, tubular filaments (hyphae) of a fungus and the roots of higher plants. The association usually enhances the nutrition of both the host plant and the fungal symbiont. The establishment and growth of certain plants (e.g., citrus plants, orchids, pines) depends on mycorrhizae; other plants survive but do not flourish without their fungal symbionts.
mycoses See fungal diseases
mycotoxin Toxin produced by a fungus. Numerous and varied, myc- otoxins can cause hallucinations, skin inflammation, liver damage, hem¬ orrhages, miscarriage, convulsions, neurological disturbances, and/or death in livestock and humans. The best-known mycotoxins are aflatoxin, ergot toxin, and the agents of mushroom poisoning.
Myerson, Goldie See Golda Meir
mynah or myna \'mI-no\ Any of several Asian songbird species of the starling family (Stumidae). The hill mynah ( Gracula religiosa) of southern Asia, called the grackle in India, is about 10 in. (25 cm) long and glossy black with white wing patches, yellow wattles, and orange bill and legs. In the wild, it chuckles and shrieks; caged, it learns to imitate human speech far better than its chief rival, the gray parrot. The common, or Indian, mynah ( Acridotheres tristis ) was introduced into Australia, New Zealand, and Hawaii. The crested mynah (A. cristatellus ), native to China and Indo¬ nesia, was introduced into British Columbia, Canada, but has not spread.