[Biological agents for controlling the density of blood-sucking black flies (Diptera: Simuliidae) in the north of Armenia].

Biological agents were found to have high larvicidal activity against Simuliidae of two Bacillus thuringiensis spp. israelensis strains. To reduce the number of the pre-imago stages of black flies, the biological agent BLP-2477 should be used as most effective from an environmental point of view.

[Effect of mechanical stress on lon mutant strain of Escherichia coli K-12]. / Vliianie mekhanicheskikh kolebanii na zhiznedeiatel'nost' lon-mutantnogo shtamma Escherichia coli K-12.

It was found that, depending on their frequency, mechanical vibrations (MVs) can either stimulate (4 Hz) or inhibit (50 Hz) the growth and the division of the lon mutant of Escherichia coli K-12. Similar effects were observed when the MV-treated nutrient medium was inoculated with untreated mutant cells. MVs enhanced the motility of mutant cells and the fragmentation of filament cells always present in the populations of lon mutants.

[The effect of magnetic fields on the growth and division of the lon mutant of Escherichia coli K-12]. / Vliianie magnitnykh polei na rost i delenie lon mutanta Escherichia coli K-12.

It was shown that the static magnetic field (SMF) and electromagnetic field (EMF) caused inhibition of the cell division in Escherichia coli K-12 lon mutant. The low-frequency EMF 4 Hz led to the 20% survival, but EMF at 50 Hz increased the survival of cells up to 53%. After exposure to magnetic field cells lost capacity for division and grow as filaments, unable to form the colonies on the solid media.