A Study On Intestinal Parasites Amongst Auxiliary Health Workers' Students in Kathmandu

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Further observations concerning steroidal, β-lactones. Boron trifluoride catalysed rearrangements of β-lactones in the cholestane series

B-Nor-5β-cholestane-3,3,5-diol-6-carboxylic acid 5,6-lactone 3-acetate on treatment with BF3 etherate in ether or ether-acetic anhydride gave B-norcholest-5-en-3β-ol-6-carboxylic acid 3-acetate and 19-nor-5-methyl-B-nor-5β-cholest-9(10)-en-3,3-ol-6-carboxylic acid 3-acetate, a product of the Westphalen rearrangement. B-Nor-5β-cholestan-5-ol-6-carboxylic acid 5,6-lactone under similar reaction conditions provided the product of the Westphalen rearrangement, 19-nor-5-methyl-B-nor-5β-cholest-9(10)-ene-6-carboxylic acid.

Mutations: Incidence in Drosophila melanogaster Reared on Irradiated Medium

An increase in the rate of mutation has been found in Drosophila melanogaster reared on a basic medium that was irradiated with a sterilizing dose (150,000 rads) of cobalt-60 gamma rays. In Muller-5 tests, sex-linked recessive lethals occurred only in the F(2) progenies of the male test flies obtained from breeding the parent flies on irradiated medium, while visible changes occurred in experimental cultures from both the control and irradiated media. The frequency of sex-linked recessive lethals was 0.35, 0.55, and 0.8 percent in three independent experiments. Visible changes were two to six times more frequent in the irradiated series than in the controls.