Biochemical mutants were obtained from Micromonospora chalcea, M. purpurea, and M. echinospora by using ultraviolet radiation or nitrosoguanidine. Crosses carried out between complementary nutritional mutants of the same species showed positive genetic interaction. Data are reported which indicate that the interaction between the crossed strains is due to genetic recombination. No evidence for ...

it is known that native oil-degrading microorganisms are ubiquitous. they can be isolated from contaminated soils. in this study, biodegradation experiments were carried out to evaluate the efficiency of pollutant removal by adding the selected microorganisms. five mixed cultures and 3 single bacteria strains, pseudomonas sp., arthrobacter sp. and mycobacterium sp. were isolated from hydrocarbo...

Audiovisual material accompanied by interlingual subtitles is a powerful pedagogical tool which can help improve the vocabulary learning of second-language learners. This study was intended to determine whether or not the mode (standard and reversed) of subtitling affects the incidental vocabulary acquisition of Iranian L2 learners while watching TV programs. Forty-five participants were random...

The aim of this study is to investigate the evolution of intrinsic postzygotic isolation within and between populations of Mimulus guttatus and Mimulus nasutus. We made 17 intraspecific and interspecific crosses, across a wide geographical scale. We examined the seed germination success and pollen fertility of reciprocal F(1) and F(2) hybrids and their pure-species parents, and used biometrical...