yellowcolour

airborne substance that was alleged to have been used in biological attacks in Southeast Asia from the mid-1970s to the mid-1980s.

After the communist victories in Southeast Asia in 1975, the new regimes in Vietnam and Laos launched pacification campaigns against Hmong tribes in northern Laos who had assisted the former noncommunist governments and their principal ally, the United States. That summer, refugees began to report that Laotian aircraft were dropping an oily yellow liquid that made a sound like rain when it fell on roofs, roads, or leaves—what the Hmong called “yellow rain.” High-dose exposure to this substance reportedly caused symptoms such as bleeding from the nose and gums, tremors, seizures, blindness, and, in some cases, death. Further reports surfaced of similar experiences by Khmer tribes in Cambodia in 1978 and by anti-Soviet resistance fighters in Afghanistan in 1979.

In 1981 the United States accused the Soviet Union of supplying their allies in Laos and Vietnam with trichothecene mycotoxins, a poison produced by fungi that was known to have potential as a biological weapon. Soviet officials denied the charge, and some leading U.S. scientists also questioned the evidence, saying that there were plausible natural causes for the events and symptoms, such as the airborne release of feces by swarms of giant Asian honeybees. Critics also questioned the reliability of the refugees’ testimony and the integrity of laboratory analyses conducted on samples of the substance. To this day, the source of the yellow rain is not definitively settled.

the use of lurid features and sensationalized news in newspaper publishing to attract readers and increase circulation. The phrase was coined in the 1890s to describe the tactics employed in furious competition between two New York City newspapers, the World and the Journal.

Joseph Pulitzer had purchased the New York World in 1883 and, using colourful, sensational reporting and crusades against political corruption and social injustice, had won the largest newspaper circulation in the country. His supremacy was challenged in 1895 when William Randolph Hearst, the son of a California mining tycoon, moved into New York City and bought the rival Journal. Hearst, who had already built the San Francisco Examiner into a hugely successful mass-circulation paper, soon made it plain that he intended to do the same in New York City by outdoing his competitors in sensationalism, crusades, and Sunday features. He brought in some of his staff from San Francisco and hired some away from Pulitzer’s paper, including Richard F. Outcault, a cartoonist who had drawn an immensely popular comic picture series, The Yellow Kid, for the Sunday World. After Outcault’s defection, the comic was drawn for the World by George B. Luks, and the two rival picture series excited so much attention that the competition between the two newspapers came to be described as “yellow journalism.” This all-out rivalry and its accompanying promotion developed large circulations for both papers and affected American journalism in many cities.

The era of yellow journalism may be said to have ended shortly after the turn of the century, with the World’s gradual retirement from the competition in sensationalism. Some techniques of the yellow-journalism period, however, became more or less permanent and widespread, such as banner...

plant disease once thought to be caused by a virus but now believed to be of mycoplasmal (bacterial) origin. It is found over much of the world wherever air temperatures do not persist much above 90° F (32° C). A wide range of species of plants are susceptible, including many wild and cultivated plants, both vegetables and garden plants. Typical symptoms include yellowing (chlorosis) of young shoots, stiff and erect bunchy growth, greenish and distorted or dwarfed flowers, and general stunting or dwarfing. Leafhopper insects serve as transmitting agents when they feed on an infected plant and then on a healthy one. No transmission occurs through leafhopper eggs or plant seed. The mycoplasma is perpetuated in overwintering weed and crop plants, in propagative parts (bulbs, corms, tubers), and in leafhoppers in mild climates. The mycoplasma is destroyed in plants and leafhoppers subjected to temperatures of 100° to 108° F (38° to 42° C) for two to three weeks; thus, aster yellows is rare or unknown in many tropical regions.

Control is effected chiefly by excluding the leafhopper carriers, by promptly removing diseased crop and weed plants as well as all overwintering susceptible weeds, and by spraying or dusting with a contact insecticide. Oxytetracycline antibiotics effect remission of symptoms in new growth.