Effect of storage time and cryoprotectant concentrations on the fertilization rate and hatching rate of cryopreserved sperm in red seabream (Pagrus major Temminck & Schlegel, 1843)

This study examined the effects of storage time and cryoprotectant concentrations on the post-thaw sperm of red seabream, Pagrus major. Sperm treated with 12%, 15%, 18% and 21% DMSO were cryopreserved for 10, 30, 60 and 360 days, and fertilization and hatching rates were analysed. For all groups, there were no differences in the fertilization rates and hatching rates between sperm cryopreserved for < 60 days and fresh sperm (98.8 +/- 0.8%, 96.4 +/- 1.3%). However, for sperm cryopreserved for 360 days, both fertilization rates (88.6 +/- 3.0% to 7.0 +/- 1.9%) and hatching rates (79.4 +/- 7.2% to 3.3 +/- 0.8%) decreased drastically. Furthermore, the cryoprotectant concentrations affected sperm quality significantly (P < 0.05). When cryopreserved for 360 days, sperm treated with 15% DMSO obtained the best results compared with other concentrations. We suggest that 15% DMSO may be an effective cryoprotectant for long-term sperm cryopreservation of red seabream.

对Allen的时间理论的某些改进

Ａｌｌｅｎ的时间理论因直观、易懂而倍受推崇，但它存在不能处理连续变化事件等缺欠。本文提出更为一般的时间理论框架，以扩展Ａｌｌｅｎ的理论，本框架的特点为：（ｌ）将Ａｌｌｅｎ的理论纳入其中；（２）可由时间点构造时区，并可处理时区和时间点；（３）以时间元素集的２Ｄ图形表示为基础的约束传播算法，既高效又可视化。