SCIENCE/TECHNOLOGY CONCENTRATES Science Red dye No. 3 affects dopamine in rat's brain Red No. 3, a food dye known chemically as erythrosin B, partially blocks the uptake of dopamine in brain cells from rats, according to Ellen K. Silbergeld and Jeffrey A. Lafferman of the National Institute of Neurological & Communicative Disorders & Stroke [Science, 205, 410 (1979)]. Using synaptosomes prepared from rat caudate nucleus, the scientists show that the compound is about 1/100th as effective an inhibitor of dopamine uptake as amphetamine. Such a finding is consistent with the theory that Red dye No. 3 can produce hyperactivity in some children. However, the researchers caution that they do not know whether the dye can pass through the bloodbrain barrier in a living animal, and hence, whether it has any effect in vivo. "This study is provocative," Silbergeld says, "but it doesn't prove that dyes in our food can affect the brain."
Child's brain has more synapses than adult's Very young children have more synapses, or connections, among nerve cells in their brains than do adults, according to Peter Huttenlocher, a pediatric neurologist at the University of Chicago. Previously, most scientists had thought that brain synapses increase with age and intellectual development. Instead, Huttenlocher finds that the density of synapses in parts of the brain where intellectual activity abounds actually peaks between the first and second years of life, eventually declining about 50% by the mid-teens. There's little further change in density until much later in life. Though infants have more synapses, their brain cells appear "immature" and are clearly distinguishable from those of adults, he adds.
Vitamin D affects green plant growth Vitamin D and several of its analogs promote plant root growth, according to phytochemists at the University of Fribourg in Switzerland [Nature, 280, 230 (1979)]. Though forms of vitamin D have been found in plants, "so far no function has been proposed for them," the Swiss scientists note. Vitamin D derivatives are widely recognized as controlling mineral metabolism in the bones of mammals. The Swiss researchers, however, now say that vitamin D2 and the analog dihydrotachysterol increase root growth in diverse species, including aspens and beans.
Nobel Laureates decry Soviet actions Five American Nobel Laureates last week called on the Soviet Union to "foster a climate free of political, ethnic, and racial prejudice and persecution" if it wants to encourage scientific cooperation. The five are chemists Christian B. Anfinsen of the National Institutes of Health, Paul J. Flory of Stanford University, and Edward B. McMillan of Lawrence Berkeley Laboratory; physicist Owen Chamberlain of the University of California, Berkeley; and Max Delbruck of Califor18
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nia Institute of Technology, who received the prize for physiology and medicine. In an open letter to Soviet President Leonid Brezhnev, Ambassador to the U.S. Anatoly Dobrynin, and Soviet Academy of Sciences president A. P. Aleksandrov, they charge that antiSemitism "continues to poison the atmosphere of cooperation" between the two countries. Furthermore, political restrictions on Soviet scientists participating in international exchanges "have corrupted the very concept of scientific cooperation."
Booster upgrades linear accelerators cheaply A series of superconducting devices that can upgrade heavy-ion linear accelerators at a reasonable price is being constructed at a facility at the State University of New York, Stony Brook, in an effort led by California Institute of Technology physicist James Mercereau. The devices, which act as superconducting resonators, can be added to existing equipment at a fraction of the cost it would take to build an equivalent accelerator. The SUNY accelerator, for example, will have its power rating raised to 25 million volts from its current 10 million volts for about one seventh the cost of building a new accelerator having the higher power rating.
Technology Superconducting magnets for fusion work Six giant superconducting magnets are being built for the Department of Energy's Oak Ridge National Laboratory fusion program. Five—two from U.S. suppliers and three from overseas under an agreement with the International Energy Agency—will use niobium-titanium superconducting alloys. One, to be supplied by Westinghouse, will use niobium-tin. Westinghouse says its 32-ton, 18-foot-high magnet will produce a magnetic field more than five times stronger than those in today's largest electrical generators, or about 150,000 times the strength of the earth's magnetic field. The magnet will be cooled by liquid helium to its operating temperature of - 4 5 2 ° F. Delivery is scheduled for late 1981.
Contact adhesives present fire hazard Some flammable contact adhesives present fire hazards in ordinary household use, concludes a study by Dow Chemical. The designation "flammable" means that the flash point for the compound is between 20° and 80° F. Dow says vapors from the solvents of such adhesives—usually toluene, hexane, naphtha, or acetone—are heavier than air. They can build up along the floor or in basements during large, home-repair projects to the point that an open flame, an electrical spark, or even a static spark may ignite them. Last summer the Consumer Product Safety Commission removed from the market "very flammable" contact adhesives—those with flash points of less than 20° F. Adhesives based on chlorinated solvents, though more expensive, are nonflammable, Dow notes.
