BACKGROUND Vibrio cholerae non-O1/ non-O139 serogroups have been reported to cause sporadic diarrhoea in humans. Cholera toxins have been mostly implicated for hypersecretion of ions and water into the small intestine. Though most of the V. cholerae non-O1/ non-O139 strains lack these cholera toxins, several other innate virulence factors contribute towards their pathogenicity. The environmenta...

Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt) have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to ...

Copepods and brine shrimp, which represent different species of zooplankton with similar inertial time constant, can behave very differently when subjected to velocity gradients in unsteady or turbulent flows. Upon sensing hydrodynamic disturbances, copepods can respond with rapid acceleration and high speed. Brine shrimp, on the other hand are more passive and capable of only small relative sw...

the crustacean paramysis intermedia is one of the most important zooplanktons which is used as food by aquatic animals in estuaries and marine environments. regarding the existence of this zooplankton stocks in the persian gulf and oman sea, knowledge on genetic structure of this species is necessary for conservation of its biological diversity and gene pool. in present study, genetic diversity...

the aim of this study was to investigate the effect of chemical fertilizer and composite of organic and chemical fertilizer on lernaeasis in cultured cyprinids was performed in two treatments and three replications in each, in 6 one-hectare ponds. in first treatment only chemical fertilizer and in the second treatment the composite of organic and chemical fertilizer were used. the other rearing...

溶解氧（DO）对湖库的生物地球化学循环、生态系统结构和功能起着至关重要的作用，也是评价水生态系统的敏感性指标.DO浓度的降低对水生态有着重要影响.结果显示，多数湖库在夏秋季热分层期间，由于温跃层较高的密度梯度、藻类衰亡和有机质的降解以及微生物的呼吸作用会消耗大量的DO，从而形成温跃层溶解氧最小值（MOM），甚至在该区域诱发厌氧状态.MOM可驱动浮游动物日夜垂向迁移，影响无脊椎动物和鱼类分布迁移模式及种群结构，破坏水体生态分布，致使生物非正常死亡，危害水体生态安全；此外，MOM也可诱发温跃层温室气体（CH4和CO2）大量形成，影响水源地水质，成为湖库生态安全隐患.目前对MOM所导致的生态风险和水质问题以及最终的控制方法已有较多研究成果，但缺乏综述性的研究.本文从MOM研究历史、研究方法、形成原因、生态风险及控制方法等方面进行论述，并展望今后研...