Quantitative structure-activity studies of substituted benzyl chrysanthemates: 4. Physicochemical properties and the rate of progress of the knockdown symptom induced in house flies

A procedure to evaluate the knockdown activity of pyrethroids against house flies in which metabolic factors could be eliminated as far as possible was established. With piperonyl butoxide and NIA 16388 as the inhibitors of oxidative and hydrolytic metabolism, respectively, the “intrinsic” knockdown potencies of 22 substituted benzyl (1R)-trans-chrysanthemates and related compounds were determined 2.5–3 hr after topical application to house flies. From the intrinsic knockdown potency and the rate of progress of the knockdown symptom from the earliest stage of intoxication, a “penetration” rate constant was estimated by first-order kinetics using a two-compartment model. The rate constant was correlated quantitatively with the hydrophobic parameter of the molecule. The lower the hydrophobicity, the higher the rate constant within the range of compounds used in this study.     

Characterization and distribution of Staphylococcus sp. implicated for improvement of fish sauce odor

ABSTRACT:   The two Staphylococcus strains that had been isolated from fish sauce mush (moromi) made from frigate mackerel in Japan and proved to improve fish sauce odor, were examined for their taxonomic positions. The sequence analysis based on 16S rRNA and rpoB showed that the two strains, R4Nu and R5G, had an identical sequence with sequence identities of 99.5% and 99.0% to the above two genes from the closest species of S. nepalensis , respectively. A DNA hybridization test of the two strains showed more than 80% DNA similarity with S. nepalensis , thus confirming the above-mentioned species identification. Polymerase chain reaction primers specific to the strain isolated from fish sauce mush were designed from rpoB and examined for the distribution of this species to various fish sauces made in Asian countries as well as to fish sauce starter (malt) made from soy beans and barley in Toyama Prefecture, Japan. The amplified DNA fragment bearing the S. nepalensis gene was detected in the enriched culture of the malt, although no positive reaction was shown with fish sauce samples. These results suggest that S. nepalensis indebted to improve fish sauce odor was originated from the fish sauce starter malt.     

Foot rot disease of sweet potato in Japan caused by Diaporthe destruens: first report,pathogenicity and taxonomy

Journal of General Plant Pathology - Foot rot, also known as stem rot or tuber-root rot syndrome, on sweet potato occurs in sweet potato fields in Okinawa, Japan. Isolates of one fungal species...     

The electrical conductivity of post-perovskite in Earth's D' layer

Recent discovery of a phase transition from perovskite to post-perovskite suggests that the physical properties of Earth's lowermost mantle, called the D' layer, may be different from those of the overlying mantle. We report that the electrical conductivity of (Mg0.9Fe0.1)SiO3 post-perovskite is >10(2) siemens per meter and does not vary greatly with temperature at the conditions of the D' layer. A post-perovskite layer above the core-mantle boundary would, by electromagnetic coupling, enhance the exchange of angular momentum between the fluid core and the solid mantle, which can explain the observed changes in the length of a day on decadal time scales. Heterogeneity in the conductivity of the lowermost mantle is likely to depend on changes in chemistry of the boundary region, not fluctuations in temperature.