We have surveyed naturally occurring plasmids in strains of Bacillus subtilis and the closely related species B. mojavensis and B. licheniformis. Previous studies have failed to find host-benefitting functions for plasmids of these species, suggesting that these plasmids are nonmutualistic. Only one type of plasmid was found in each plasmid-bearing strain, suggesting that most of the plasmids i...

Interactions among greenbug, Schizaphis graminum (Rondani), Russian wheat aphid, Diuraphis noxia (Mordvilko), and bird cherry-oat aphid Rhopalosiphum padi (L.) were examined on wheat plants (Triticum aestivum L., cultivar TAM 107). Nymphs were released on the plants as conspecific and heterospecific pairs of either first or fourth instars and evaluated for survival, developmental time, fecundit...

China is a country that is arousing a large amount of interest as a new mega-market, as it opens itself to a market-orientated economy and expands at a remarkable rate. However, the influx of international investment, new business opportunities and advertising from overseas has seen Chinese consumers being exposed to potentially offensive advertising products and images. While some products and...

<p style='text-indent:20px;'>Environmental factors and random variation have strong effects on the dynamics of biological ecological systems. In this paper, we propose a stochastic delay differential model two-prey, one-predator system with cooperation among prey species against predator. The has global positive solution. Sufficient conditions existence uniqueness an ergodic stationary di...