Word: drs
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Dates: during 1960-1969
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Teen-agers from families of high social status smoke less than those from families of low social status, according to a Harvard study. For the university's school of public health, Drs. Eva J. Salber and Brian MacMahon surveyed the senior high school in Newton, Mass., which they chose because the social cross section is similar to much of the urban U.S. To get serious and responsible answers, the researchers got the questionnaires filled out during school hours and required students to sign them, promising that neither parents nor teachers would ever learn what was in them...
...percentage of students who smoke cigarettes, Drs. Salber and MacMahon report in the American Journal of Public Health, rises among boys from 32.7% in the highest social class* to 43.6% in the lowest, and among girls from 36.4% to 47.6%. More striking still is the distribution of heavy smokers. Among boys in the top social class, only 7.4% smoke five packs or more a week, and among girls only 3.3%; but in the lower group, the figures are 12.1% for boys and 8.9% for girls...
...Infective Heredity." Recent research, said Dr. Horsfall, has shown that gene mutations can be produced by changes in the environment, and the mutant strains will breed true. It began, he recalled, with the little-recognized achievement of three Rockefeller Institute scientists, Drs. Oswald Avery, Colin MacLeod and Maclyn McCarty in 1944. They showed that if nucleic acid from the genetic material of one strain of pneumococcus germs was stirred in with a batch of pneumococci of another strain, the second strain picked up the inherited traits of the first, and then, "in enduring continuity," bred true from cell to daughter...
...greatest interest to Drs. White and Currens were the coronary arteries. These were two to three times the normal size, but far from being free of disease. Between the layers of the arterial tubes were fibrous areas and atherosclerotic deposits, some of them calcified. At several points, these deposits cut down the bore of the artery by as much as 30%, but that is plainly far better than the total stoppage that occurs in many heart attacks. The doctors cannot be sure whether DeMar inherited big coronaries or grew them by running. What is certain and significant is that moderate...
Organized Elements. The evidence of extraterrestrial bugs is less convincing. Meteorite connoisseurs have long known that rare meteorites called carbonaceous chondrites contain carbon compounds found in living organisms. Drs. Claus and Nagy got small samples of five chondrites, crushed them in water or glycerol on glass slides and examined them under the microscope. In three samples from two meteorites (Orgueil, which fell in 1864, and Ivuna in 1938) they found large numbers of "organized elements" that do not resemble any known mineral form. Their guarded conclusion: the organized elements may be microfossils that came to earth aboard the meteorite...