Quality control of long-term mass-reared Aedes albopictus for population suppression

The endosymbiotic bacterium Wolbachia is being developed as a tool to suppress mosquito populations and their transmitted pathogens, with successful field trials in multiple countries having resulted in efforts to scale up the capacity to mass-produce mosquitoes for release. However, major challenges exist to achieving this goal, including concerns that mass-reared mosquitoes will adapt to laboratory conditions during long-term maintenance and experience inbreeding depression, resulting in poor performance of the released mosquitoes in the field. Here, we assessed the performance of the Aedes albopictus HC line infected with a triple-strain Wolbachia after mass-rearing at scaled-up densities of up to 15 million mosquitoes per week for over 50 generations. In comparison with the wild-type GUA line, the HC mosquitoes had desirable characteristics for mass-rearing and release, including robust male mating competitiveness, high female reproductive capacity, reduced vector competence for dengue virus, and increased Wolbachia density. Although the larval survival rate of the HC and GUA lines was similar, the HC larvae developed significantly faster, possibly because of up-regulation of the molting hormone 20-hydroxyecdysone-related gene E75 in the HC larvae. Our results indicate that over many generations mass-reared mosquito lines can retain their quality if large effective population sizes with sufficient genetic heterogeneity are maintained under optimized rearing conditions and demonstrate the long-term feasibility of deploying Wolbachia-based approaches for area-wide management of mosquito vectors for disease control.

     

制材工艺方案的优化设计

结合我国制材生产实际，在传统带锯工艺方案设计的基础上，借助经济滂和计算机，对带锯制材工艺进行方案优化设计。并开发出相应的应用软件，大大加了设计进度，增强制材工艺设计在招标、投标中的竞争能力，为实现制材工艺的优化设计，提供了有效的工具。     

维修计划的优化设计

均衡生产中资源配置是一类生产问题的难题.通过分析和探讨,在对有限资源和时间限制条件下,运用拉格朗日函数,将离散问题连续化,建立了维修计划二次规划的目标函数;通过计算机求解,得出维修计划的最优方案.该数学模型具有广泛的适用性.     

基于ELECTRE的建筑设计方案的优化决策

以南京地区为例,通过建立建筑设计方案评价指标体系,并用模糊综合评判法确定各指标的权重。运用Ecotect具备的模拟功能建立性能化建筑设计方案评价指标,进行建筑项目综合性能模拟,以达到设计方案的优化。采用ELECTRE方法,通过规范决策矩阵来进行多方案多属性的决策,最终得到建筑设计整体综合性能的最优方案。     

森林工程网络虚拟实验室方案设计与构建方法的研究

提出建立森林工程网络虚拟实验室的主体方案,以Labview软件为平台开发仿真实验,利用ActiveX设计交互式网络环境,并嵌入交互式网络动画,实验者像在真实环境中一样完成预定实验项目,所取得效果甚至优于真实实验,对提高实验教学水平有着重要实践价值。     

Toxicity and repellence of Taiwanese indigenous djulis, Chenopodium formosaneum, against Aedes albopictus (Diptera: Culicidae) and Forcipomyia taiwana (Diptera: Ceratopogonidae)

The biological activity of djulis (Chenopodium formosaneum) extracts was evaluated against mosquitoes and biting midges. Djulis extracts were relatively nontoxic to Aedes albopictus larvae. However, they showed interesting repellence against adult mosquitoes as estimated by the median effective dosages (ED₅₀). ED₅₀ values for djulis extracts against mosquito adults in descending order were: seed extracted with methanol (0.83 %), seed extracted with dichloromethane (0.66 %), leaf extracted with methanol (0.50 %), and leaf extracted with dichloromethane (0.40 %). Field tests also suggested that djulis methanol extracts were effective at about a 1 % level against biting midges (Forcipomyia taiwana). A total of 15 and 20 compounds accounting for 88.8 and 79.9 % in the seed and leaf extract, respectively were identified by gas chromatography coupled to mass spectrometry (GC–MS). Among these, 9, 12-octadecadienoyl chloride, (Z, Z) was found in both as well as being the major constituent in the leaf extract (35.7 %). Further studies on the repellent property of the extracts against mosquitoes and biting midges are warranted.     

植物营养诊断方法研究进展

植物营养诊断技术已成为指导施肥的重要技术手段,目前常用的诊断方法有植物组织分析诊断法、土壤分析诊断法、植物外观诊断法、田间施肥试验诊断法、生理生化分析诊断法、植物组织液分析诊断法、无损测试技术及其他诊断方法等。各种方法各有利弊,实际生产中必须结合具体情况,综合应用几种诊断方法,才可得出正确的诊断结果。     

桉树人工林营养特性与施肥技术研究进展

对桉树人工林的养分需求规律、树体的营养诊断、施肥时期和施肥方式、施肥种类和施肥量等进行了探讨,建议应用计算机推荐施肥系统,构建基于3S技术的桉树人工林营养管理系统,应用营养诊断技术配制并施用桉树专用复合肥,进一步完善施肥技术.     

白蚁生殖活动中的化学信息交流

白蚁生殖包括两性生殖和产雌孤雌生殖,两性生殖中又有近亲交配和远亲交配的周期性轮换。两性生殖包括配对、串联、交配3个阶段,生殖活动的信息化学物质包括配对性信息素、串联性信息素和交配性信息素。配对性信息素由成虫腹板腺、背板腺或后腹板腺分泌,目前已有27种白蚁的配对性信息素得到鉴定,化学成分主要为不饱和脂肪醇和醛,有的配对性信息素含有种特异性微量组分。串联性信息素和交配性信息素还需要进一步证实。表皮碳氢化合物和卵表特异性蛋白质成分也称为识别信息素,用于种间、种内及不同生殖状况个体的识别,从而影响配偶选择等生殖活动。栖北散白蚁和高山象白蚁的蚁后信息素已进行鉴定,其作为引发信息素调节不同品级生殖系统的发育。     

基于土地资源优化配置模型的黄河三角洲宜林牧地绿化研究

首先从生态学的角度,根据黄河三角洲优化配置原则,对土地适宜方向与土地利用现状相匹配,甄别出需要调整的类型,以黄河三角洲高效生态农业建设为目标,保持一定的耕地总量,构建黄河三角洲土地资源优化配置模型;然后提出了土地立地类型划分标准,对优化配置后的宜林牧地进行归类;最后,对未绿化的宜林牧地进行树种配置,全力打造黄河三角洲生态绿洲。