The viability of pneumococcus, Type I, sprayed into the atmosphere from a liquid suspension was measured as a function of the relative humidity. When broth, saliva, or 0.5 per cent saline solution is employed as the suspending medium, a very high mortality rate is observed at relative humidities in the vicinity of 50 per cent. However, at humidities above or below this value the microorganisms ...

Inoculation of the CAM of the 10-day chick embryo with endotoxin preparations derived from the meningococcus and other Gram-negative microorganisms has been shown to result in multiple hemorrhages and death of the embryo within a few hours. Evidence has been presented to indicate that this lethal effect is specific for the general class of endotoxins derived from Gram-negative bacteria. Suscept...

characteristic studied (aneuploidy, length of time in culture, and rate of growth) could be correlated significantly with thermosensitivity. All the cultures of tumor-derived and tumor-producing cells exhibited the same high degree of thermosensitivity, i.e., death of 95% of the cells after 2 hr exposure at 42.5°. All the cultured normal, nontumor-producing cells exhib ited a lower degree of h...

Soybean, Glycine max L., and elodea, Elodea canadensis Michx, leaves were exposed to sublethal and lethal temperatures and examined by light microscopy. Loss of chlorophyll and swollen chloroplasts were observed in cells of elodea leaves exposed to sublethal temperatures. At the thermal death point of leaf cells of elodea and soybean, there was a disorganization of the tonoplast membrane, plasm...

PROTECTIVE EFFECT OF SEROTONIN AND OF PARA-AMINOPROPIOPHENONE AGAINST LETHAL DOSES OF X-RADIATION

N assessing the hereditary effects of radiation on human populations, it is very I important to know the population dynamics of mutant genes induced by radiation and their effect on population fitness. It is still controversial whether radiation-induced mutations are deleterious in the heterozygous condition, though they appear to be mostly deleterious in the homozygous condition. A pioneering ...

Glued mutations in Drosophila comprise an essential complementation group with complex developmental effects. The original Glued mutation (Gl) has dominant nonlethal effects in heterozygous flies, principally on the morphogenesis of the visual system. Gl also has a recessive lethal effect early in development. Mutations that reverse the dominant visual effects of Gl (GlR mutations) were induced...