Hz-2V is one of only a very few sexually transmitted viruses currently known in insects. Replication of this insect pathogenic virus results in sterility of infected moths rather than mortality. The sterility of the i...Hz-2V is one of only a very few sexually transmitted viruses currently known in insects. Replication of this insect pathogenic virus results in sterility of infected moths rather than mortality. The sterility of the infected host is a consequence of virus directed malformation of adult reproductive tissues, which in females results in cellular proliferation and hypertrophy of these tissues. Virus replication has additional ramifications in infected females. Infected females produce more mating pheromones and attract more mates than healthy females, ultimately facilitating virus transmission and enhancing viral fitness. The molecular mechanisms used by the virus to manipulate the host to enhance its fitness are yet to be determined. Unraveling the underlying principles of these mechanisms promises to enhance our understanding of insect reproductive physiology, as well as provide molecular tools for use in novel approaches in sterile insect control programs.展开更多
Dimensional control is one of the most important challenges in the shipbuilding industry. In order to predict assembly dimensional variation in hull flat block construction, a variation stream model based on state spa...Dimensional control is one of the most important challenges in the shipbuilding industry. In order to predict assembly dimensional variation in hull flat block construction, a variation stream model based on state space was presented in this paper which can be further applied to accuracy control in shipbuilding. Part accumulative error, locating error, and welding deformation were taken into consideration in this model, and variation propagation mechanisms and the accumulative rule in the assembly process were analyzed. Then, a model was developed to describe the variation propagation throughout the assembly process. Finally, an example of fiat block construction from an actual shipyard was given. The result shows that this method is effective and useful.展开更多
基金supported by the Cooperative State Research Extension, Education Service, U. S. Department of Agriculture, the Massachusetts Agri-cultural Experiment Station and the Department of Plant,Soil and Insect Sciences, under Project No. MAS00909
文摘Hz-2V is one of only a very few sexually transmitted viruses currently known in insects. Replication of this insect pathogenic virus results in sterility of infected moths rather than mortality. The sterility of the infected host is a consequence of virus directed malformation of adult reproductive tissues, which in females results in cellular proliferation and hypertrophy of these tissues. Virus replication has additional ramifications in infected females. Infected females produce more mating pheromones and attract more mates than healthy females, ultimately facilitating virus transmission and enhancing viral fitness. The molecular mechanisms used by the virus to manipulate the host to enhance its fitness are yet to be determined. Unraveling the underlying principles of these mechanisms promises to enhance our understanding of insect reproductive physiology, as well as provide molecular tools for use in novel approaches in sterile insect control programs.
基金Supported by the National Science Foundation of China (Granted No.70872076) and Science Innovation Action Planning of Shanghai 2011 (No.11dz1121803).
文摘Dimensional control is one of the most important challenges in the shipbuilding industry. In order to predict assembly dimensional variation in hull flat block construction, a variation stream model based on state space was presented in this paper which can be further applied to accuracy control in shipbuilding. Part accumulative error, locating error, and welding deformation were taken into consideration in this model, and variation propagation mechanisms and the accumulative rule in the assembly process were analyzed. Then, a model was developed to describe the variation propagation throughout the assembly process. Finally, an example of fiat block construction from an actual shipyard was given. The result shows that this method is effective and useful.