1364 From late 1930, lethal genes have been used as ge netic markers to detect concealed variation in Droso phila populations [1–4]. In order to study lethal genes a lethal balanced strain is required. This strain is a ge netic construction involving a pair of homologous chromosomes with the following characteristics: they have to contain natural or induced chromosomal in versions to block reco...

background: there is unprecedented increase in the processing and packaging of many plant materials into food supplements, herbal medicine, skincare and cosmetic products for human needs. baphia nitida is used for topical skincare products. toluene, a toxic aromatic solvent, is increasingly being used in the production of these skincare and cosmetic products in many industries. this study asses...

the two-spotted spider mite, tetranychus urticae koch, is a polyphagus pest which infests wide range of field, garden and greenhouse crops worldwide. pesticide applications against this pest have caused development of resistance, undesirable effects on non target organisms and environment and secondary pest outbreak. in recent years, herbal essential oils have received attention as natural plan...

Lethal effects of trinitrotoluene (TNT) to juvenile sheepshead minnows (JSHM) (Cyprinodon variegatus) were assessed in ten-day water exposures. Ten-day median lethal concentrations (LC50s) were 2.3 and 2.5 mg L(-1), the 10-d median lethal residue value (LR50) was 26.1 micromol kg(-1) wet weight (ww), and bioconcentration factors (BCFs) ranged from 0.7 to 2.4 L kg(-1). The lethal effects of TNT ...

IN comparative studies of the mutagenic action of ionizing and ultraviolet radiation on conidia of the fungus Glomerella (5) it was evident that the shape of the mutation curve was different for the two types of radiation. The dose-mutation curve for the surviving spores was essentially linear for the ionizing radiations, but with the ultraviolet radiation the mutation curve rose with increasin...

An attempt has been made to use low-voltage alternating current to kill microorganisms such as Escherichia coli. The bactericidal effect depends on the energy passing through the suspension and on the time during which the cells are left standing in the medium after the treatment. Most of the toxicity is due to an indirect effect developed with unalterable electrodes in the presence of chloride...

Evidence was obtained which indicates that the lethal effect of 5-iodouracil (IUra) on bacteriophage T4 is not due to a mutagenic process. T4td8rII (thymine requiring, rapid lysis) double mutants were constructed. Reversion of T4td8rII to r(+) was measured. First, reversion by growth in the presence of the structural analogues chlorouracil (ClUra) and bromouracil (BrUra) did not correlate with ...

Primary aortoduodenal fistula (ADF) is a rare but morbid diagnosis. Here, we present the case of a patient with a primary ADF that resulted in mortality. Despite multiple attempts at radiographic and endoscopic diagnosis, the fistula did not declare itself until the patient exsanguinated. Given the morbidity associated with ADF and the imperfection of associated diagnostic studies, a high index...

Freshwater sponges in the Great Lakes St. Lawrence River system overgrow and kill introduced zebra (Dreissena pulymorpkza) and quagga mussels (DreisLse?aa bugerasis) on solid substrates. Sponges overgrow and smother mussel siphons, thereby interfering with normal feeding and respiration. We tested the significance of sponge-enhanced mussel mortality by repeated sampling at several sites where b...