[Objective] This study aimed to investigate rapid multiplication of Apocynum by tissue culture so as to provide plantlet sources for its industrialized cultivation. [Method] The asepsis seedlings were obtained by deal...[Objective] This study aimed to investigate rapid multiplication of Apocynum by tissue culture so as to provide plantlet sources for its industrialized cultivation. [Method] The asepsis seedlings were obtained by dealing with Apocynum seeds. Its cotyledons, hypocotyls and shoot tips were cultured on the media containing different concentrations of hormones. Finally, the influence of different hormone combinations on differentiation of cotyledons and hypocotyls, rapid multiplication of shoot tips, rapid multiplication of regenerated shoots, and rooting of test-tube plantlets was com- pared. [Result] MS＋2.0 mg/L BA＋0.03 mg/L NAA and MS＋0.07 mg/L NAA were the optimum medium for inducing regenerated buds from cotyledons and hypocotyls re- spectively; MS＋2.0 mg/L BA＋0.02 mg/L NAA was the best medium for rapid multi- plication of shoot tips; MS＋1.9 mg/L BA＋I.7 mg/L NAA was the best medium for rapid multiplication of regenerated buds： and 1/2MS＋0.6 mg/L NAA was the best medium for inducing roots. [Conclusion] The optimum hormone combination was de- termined for Apocynum rapid multiplication by tissue culture, which provides technical support on Apocynum industrialized cultivation.展开更多
The use of cholera vaccines has been increasingly recognized as an effective control measure in cholera endemic countries. However, guidelines for using vaccination during cholera outbreaks are still to be established...The use of cholera vaccines has been increasingly recognized as an effective control measure in cholera endemic countries. However, guidelines for using vaccination during cholera outbreaks are still to be established, and it remains an open question as to how and when the vaccines should be deployed to best control ongoing cholera outbreaks. Here we formulate a new optimal control model to assess the value of cholera vaccines in epidemic settings and cost-effective optimal times to deploy a vaccine. Our results suggest that as long as the vaccine prices are sufficiently low, vaccination should always start from or immediately after the onset of a cholera outbreak.展开更多
基金Supported by Science and Technology Development Program of Jilin Province(20110909)Youth Foud of Baicheng Normal University(200801)~~
文摘[Objective] This study aimed to investigate rapid multiplication of Apocynum by tissue culture so as to provide plantlet sources for its industrialized cultivation. [Method] The asepsis seedlings were obtained by dealing with Apocynum seeds. Its cotyledons, hypocotyls and shoot tips were cultured on the media containing different concentrations of hormones. Finally, the influence of different hormone combinations on differentiation of cotyledons and hypocotyls, rapid multiplication of shoot tips, rapid multiplication of regenerated shoots, and rooting of test-tube plantlets was com- pared. [Result] MS＋2.0 mg/L BA＋0.03 mg/L NAA and MS＋0.07 mg/L NAA were the optimum medium for inducing regenerated buds from cotyledons and hypocotyls re- spectively; MS＋2.0 mg/L BA＋0.02 mg/L NAA was the best medium for rapid multi- plication of shoot tips; MS＋1.9 mg/L BA＋I.7 mg/L NAA was the best medium for rapid multiplication of regenerated buds： and 1/2MS＋0.6 mg/L NAA was the best medium for inducing roots. [Conclusion] The optimum hormone combination was de- termined for Apocynum rapid multiplication by tissue culture, which provides technical support on Apocynum industrialized cultivation.
基金J. Wang acknowledges partial support from the National Science Foundation under Grant Nos. 0813691 and 1216936. Z. Mukandavire was supported by the UF Science for Life Program, an interdisciplinary program with support from the Howard Hughes Medical Institute. The authors would like to thank the anonymous referees for helpful comments.
文摘The use of cholera vaccines has been increasingly recognized as an effective control measure in cholera endemic countries. However, guidelines for using vaccination during cholera outbreaks are still to be established, and it remains an open question as to how and when the vaccines should be deployed to best control ongoing cholera outbreaks. Here we formulate a new optimal control model to assess the value of cholera vaccines in epidemic settings and cost-effective optimal times to deploy a vaccine. Our results suggest that as long as the vaccine prices are sufficiently low, vaccination should always start from or immediately after the onset of a cholera outbreak.
