THE OCCURRENCE OF PHYTOSEIULUS PERSIMILIS ATHIAS-HENRIOT (ACARINA:PHYTOSEIIDAE) IN AN ORCHARD IN VICTORIA

b
High numbers of the predatory mite, Phytoseiulus persimilis , were found on apple and nectarine trees in a commercial orchard at Werribee, Victoria in February 1981. In the following season, again it was not detected on trees or broad-leaved weeds in the orchard until late summer. Slide-dip tests on the Werribee population of P. persimilis and a population originating from strawberries in Sydney, New South Wales, showed that azinphos-methyl was equally toxic to the 2 strains and DDT was considerably less toxic to both.     

Isolation of lymphoma cell variants resistant to killing by glucocorticoids

Pseudo-diploid (2s) and pseudo-tetraploid (4s) cultured mouse lymphoma cells are killed by physiological concentrations of adrenal glucocorticoid hormones. A method is described for the single-step isolation of 2s and 4s variants resistant to dexamethasone, a synthetic adrenal hormone. The transition from steroid sensitivity to resistance is stochastic and occurs at a rate of 3.5 × 10^?6/cell/generation. Several types of mutagens significantly increase this rate. The chromosome number, growth rate, gross morphology, and cloning efficiency of the steroid-resistant variants are not detectably different from those of their steroid-sensitive parents.     

Determinants of child mortality in south-west Uganda.

Anthropometric and sociodemographic variables were taken from 4320 children in a baseline survey carried out in March-April 1988 in the district of Mbarara, south-west Uganda. After 12 months a follow-up survey assessed the mortality of the children during the preceding year. Lack of ownership of cattle, recent arrival in the village, using candles for lighting, being of birth order higher than 5 and having a father with less than 8 years of schooling were significantly associated with child mortality. The addition of mid-upper arm circumference significantly improved the logistic model of socioeconomic variables and mortality and did not diminish the predictive power of socioeconomic variables in relation to increased mortality. This suggests that nutritional status and specific socioeconomic factors are both, independently, important predictors of child mortality.