MY ancestors have lived in Lhasa, Tibet, for generations. I have personally witnessed the great changes in modern Tibetan society. The total population of the region has doubled since 1951. The Fourth National Census ...MY ancestors have lived in Lhasa, Tibet, for generations. I have personally witnessed the great changes in modern Tibetan society. The total population of the region has doubled since 1951. The Fourth National Census in 1990 revealed that the human fertility rate in the Tibet Autonomous Region was 27.60 per thousand, the natural population growth rate 18.40 per thousand, and the total fertility rate of women at childbearing age 4.22.展开更多
Organic contaminants can be detected at low concentrations in drinking water, raising concerns for human health, particularly in reproduction. In this respect, we attempted to use the zebrafish as a bioindicator to de...Organic contaminants can be detected at low concentrations in drinking water, raising concerns for human health, particularly in reproduction. In this respect, we attempted to use the zebrafish as a bioindicator to detect the possible presence of these substances in drinking water, aiming to define the most relevant parameters to detect these substances, which particularly affect the development and reproduction of zebrafish. To this end, batches of30 embryos with the chorion intact were cultured in drinking waters from different sources,throughout their full life-cycle up to 5 months, in 20 L tanks. Six replicates were performed in all water groups, with a total of 24 aquariums. Two generations（F0 and F1） were studied and the following parameters were tested： in the F0 generation, survival and abnormality rates evaluated at 5 dpf（days post-fertilization） and at 5 mpf（months post-fertilization）,the onset of spawning and the fertility rate from 3 mpf to 5 mpf, and the sex ratio and underdeveloped specimens at 5 mpf. Furthermore, in the F0 offspring（F1）, survival and abnormality rates were evaluated at 5 dpf and the hatching rate at 72 hpf. These results revealed that the hatching rate is the most sensitive parameter to distinguish different levels of effects between waters during the early life stages, whereas the rate of underdeveloped specimens is more suitable at later life stages. Regarding adult reproduction, fertility rate was the most sensitive parameter. The possible reversibility or accumulative nature of such effects will be studied in future work.展开更多
文摘MY ancestors have lived in Lhasa, Tibet, for generations. I have personally witnessed the great changes in modern Tibetan society. The total population of the region has doubled since 1951. The Fourth National Census in 1990 revealed that the human fertility rate in the Tibet Autonomous Region was 27.60 per thousand, the natural population growth rate 18.40 per thousand, and the total fertility rate of women at childbearing age 4.22.
文摘Organic contaminants can be detected at low concentrations in drinking water, raising concerns for human health, particularly in reproduction. In this respect, we attempted to use the zebrafish as a bioindicator to detect the possible presence of these substances in drinking water, aiming to define the most relevant parameters to detect these substances, which particularly affect the development and reproduction of zebrafish. To this end, batches of30 embryos with the chorion intact were cultured in drinking waters from different sources,throughout their full life-cycle up to 5 months, in 20 L tanks. Six replicates were performed in all water groups, with a total of 24 aquariums. Two generations（F0 and F1） were studied and the following parameters were tested： in the F0 generation, survival and abnormality rates evaluated at 5 dpf（days post-fertilization） and at 5 mpf（months post-fertilization）,the onset of spawning and the fertility rate from 3 mpf to 5 mpf, and the sex ratio and underdeveloped specimens at 5 mpf. Furthermore, in the F0 offspring（F1）, survival and abnormality rates were evaluated at 5 dpf and the hatching rate at 72 hpf. These results revealed that the hatching rate is the most sensitive parameter to distinguish different levels of effects between waters during the early life stages, whereas the rate of underdeveloped specimens is more suitable at later life stages. Regarding adult reproduction, fertility rate was the most sensitive parameter. The possible reversibility or accumulative nature of such effects will be studied in future work.
