background: creation of artificial gametes may provide a universal solution for these patients of lacking gametes. stem cell technology may provide a way to obtain fully functional gametes. retinoic acid (ra) can initiate meiosis. several studies have demonstrated that ra can promote sperm cells differentiation from mouse embryonic stem cells (mescs) and other cells from human embryonic stem ce...

The potential of genotoxicity biomarkers as predictors of detrimental environmental effects, such as altered reproductive success of wild organisms, must be rigorously determined. Recent research to evaluate relationships between genotoxic responses and indicators of reproductive success in model animals is described from an ecotoxicological perspective. Genotoxicity can be correlated with repr...

Sexual polyploidization, as a result of 2n gamete formation, is thought to be the main process involved in the origin of polyploid plants (Bretagnolle & Thompson, 1995). These gametes, possessing the somatic rather than the gametophytic chromosome number, can be formed either during microsporogenesis (2n pollen, big pollen, diplandroidy) or megasporogenesis (2n eggs, diplogynoecy). In general, ...

this study investigated different concepts for natural-gas-fired power plants with the co2capture, and compared them based on the net plant efficiency and emission of co2. the cycles were based ona six oxy-fuel, one post-combustion and two pre-combustion capture concept. this paper presented theresults of an environmental evaluation performed by the application of the life cycle analysis (lca) ...