Evidence for transmission of aphid-pathogenic fungi by migratory flight of Myzus persicae alates

The alates of the green peach aphid, Myzus persicae, were daily trapped from the air from late October through early January and carried to laboratory for determination of fungal infection by individually rearing them for 7 d on detached cabbage leaves in Petri dishes. Among 760 alates trapped, 266 (35%) were found carrying various fungal pathogens, 87.3% of them died due to mycosis during the first 3-day period of rearing and the rest died in the following two days. Most of the deaths of the alates were attributed to entomophthoralean fungi, taking 94.4%, and the rest were the hyphomycetous fungus Beauveria bassiana. Among the Entomophthorales-killed alates, P. neoaphidis took a proportion of 66.1%, Z. anhuiensis 22.6%, E. planchoniana 9.7%, and N. fresenii 1.6%, respectively. Two alates were found suffering from cross infection of two fungal species, i.e. P. neoaphidis with Z. anhuiensis and N. fresenii, respectively. The results represent the first report on transmission of aphid-pathogenic fungi by M. persicae alates through migratory flight.     

Evidence for transmission of aphid-pathogenic fungi by migratory flight of Myzus persicae alates

The alates of the green peach aphid, Myzus persicae, were daily trapped from the air from late October through early January and carried to laboratory for determination of fungal infection by individually rearing them for 7 d on detached cabbage leaves in Petri dishes. Among 760 alates trapped, 266 (35%) were found carrying various fungal pathogens, 87.3% of them died due to mycosis during the first 3-day period of rearing and the rest died in the following two days. Most of the deaths of the alates were attributed to entomophthoralean fungi, taking 94.4%, and the rest were the hyphomycetous fungus Beauveria bassiana. Among the Entomophthorales-killed alates, P. neoaphidis took a proportion of 66.1%, Z. anhuiensis 22.6%, E. planchoniana 9.7%, and N. fresenii 1.6%, respectively. Two alates were found suffering from cross infection of two fungal species, i.e. P. neoaphidis with Z. anhuiensis and N. fresenii, respectively. The results represent the first report on transmission of aphid-pathogenic fungi by M. persicae alates through migratory flight.     

EGCG对肿瘤干细胞抑制效应研究进展

表没食子儿茶素没食子酸酯((-)-Epigallocatechin-3-gallate,EGCG)是绿茶主要活性成分之一,对肿瘤干细胞(Cancer stem cells,CSCs)具备抑制效应.综述了EGCG对CSCs迁移侵袭性、耐药性、自我更新和致瘤性等病理学特性的抑制效应及应用新策略,并对相应信号传导通路进行阐述,为深入研究EGCG抗癌的药理学效应及应用新策略提供借鉴.     

胶体金标记牛血清白蛋白及其在电场中的迁移行为

采用柠檬酸钠还原法制备了不同粒径的胶体金,对牛血清白蛋白(BSA)进行标记,考察了胶体金标记BSA的影响因素.以琼脂糖凝胶为载体介质,研究了三种粒径的胶体金及其BSA复合物在电场中的迁移行为.结果表明,pH值、离子浓度、蛋白量都会影响胶体金对BSA的标记.标记的最适条件是:无盐或极低盐浓度,pH值5.8,蛋白加入量不小于最小稳定蛋白量.胶体金及其BSA复合物在特定电场中的迁移行为类似于火箭免疫电泳,其迁移速度随着金纳米粒子粒径的增大而减小;金纳米粒子与BSA结合后迁移速度减慢,BSA的加入量对复合物的迁移速度无影响.     

New evidence for human occupation of the northern Tibetan Plateau, China during the Late Pleistocene

The described stone artifacts are recovered from the 70 m-high terrace (4600 m a.s.l.) at the southeastern shore of the Siling Co on the northern Tibetan Plateau. The terrace was formed during the Interstadial period before the LGM, ca. 40-30 ka B.P. based on paleoenvironmental research. The Paleoliths from the Siling Co provide evidence for early human occupation of the northern Tibetan Plateau. They show technological and typological affinities with the European Middle Paleolithic suggesting that the early human occupation here might relate to migratory waves during the Late Pleistocene that dispersed humans across the Old World.     

青海共和盆地高寒流动沙丘快速治理技术

研究了共和盆地流动沙丘的快速治理技术,结果表明：流动沙丘快速固定需要机械措施和生物措施相结合,机械沙障可在短期内将流动沙丘完全固定,但是,如果不采取生物措施,沙丘有可能在2～3年内复活,而生物措施固定流沙,初期效果缓慢,有时甚至难以实现。采用机械沙障将沙丘先加以固定,然后实施生物措施。这种生物与机械相结合的流动沙丘治理技术是类似共和盆地立地条件下治理流动沙丘的最佳模式。     

软件研发人力资源"候鸟现象"的Markov链模型

通过近年来数据的收集和整理,发现软件研发人力资源的流动呈现出规律性转移的现象,具有"春秋迁徙,一年为期","目标区域集中","目标企业明确"3个显著特征,因与候鸟的迁徙习性类似,称之为"候鸟现象".基于该现象的特性,提出Markov链建模.算例的预测结果表明,Markov链模型误差较小,能够有效模拟"候鸟现象"的转移规律,得出合理的计算结果.     

Nesting territory characteristics of a migratory South American forest hawk,the White-throated Hawk (Buteo albigula) (Aves: Accipitridae), in temperate rainforest remnants of Araucanía,southern Chile

During four successive breeding periods (2007–11) we characterized the nesting territories of the white-throated hawk (Buteo albigula) in southern Chile. Territories were located in mountainous areas with mature native forest (n = 17) or mature pine plantations (n = 1). Most of the territories were distant from urban centres (>2 km). Only one or two adult hawks and one young per pair/year were observed in each territory. All nest sites were located in the upper parts of ravines. Nests were built on large, living mature trees. Platforms were bulky (>50 cm diameter) and oval or round. Eggs were white and subelliptical in shape (40.0 × 50.0 mm). Hawk pairs reproduced asynchronically extending the reproductive period for 6 months. Although some white-throated hawk pairs were tolerant of human-modified habitats, it is possible that decline in forest cover represents a potential threat for the population viability of this migratory forest hawk.     

优化迁移共享的自适应令牌协议

针对写作废的一致性协议在处理迁移特征时需要2次访问的特征，提出了一种自适应的令牌协议，根据数据的读/写处理器和数据的令牌信息判断数据是否具有迁移特征.如果数据具有迁移特征，则请求者的状态变为可以避免迁移访问序列中出现写访问的状态MG，从而消除了迁移特征中的写作废次数.结果表明，所提出的自适应令牌协议在读访问时获取了数据所有权，避免了部分写失效的产生，从而使得平均失效延迟降低5%，通信量平均降低9%.
     

基于软件体系结构的构件可迁移系统容错研究

随着分布式应用的迅速发展,构件可迁移分布式系统由于其构件的可移动性,受到广泛关注。如何保证构件可迁移系统的容错,一直是研究的热点。另一方面,软件体系结构是软件系统的蓝本,对软件的设计与实现有着重要的指导作用。该文提出一种面向体系结构,并适合构件可迁移系统的容错框架。该框架不但能显式刻画软件体系结构,而且能支持构件可迁移...