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Solitary parasitoid wasps are believed to be able to adjust their oviposition behavior with host size.Host size theory shows that parasitoid′s sex ratio is related to host body size,and parasitoids prefer to lay more female eggs in larger hosts.Superparasitism happens when solitary parasitoids lay more than one eggs in one host.And in the host superparasitized by solitary parasitoids,usually only one offspring can emerge.If survival frequency differs between the two sexual offspring in the superparasitized host,the relationship between adjustment of oviposition behavior by parasitoids and sex ratio in offspring would be affected.However,little has been known about the host size model when superparasitism has been excluded.Spalangia endius is a wide distribution solitary primary ectoparasitoid of the pupae of several Dipteral insects,most of which are important pest insects.The parasitoid has been used to test the host size model.Preview studies have showed that the parasitoid prefers to lay more female offspring in larger hosts,and a less female biased sex ratio in smaller ones.In this article,offspring number and sex ratio during oviposition,and the effects of host size and parasitism sequences on offspring sex ratio of S.endius were studied using the housefly pupae as the host.The results showed that the oviposition duration of the parasitoid was(8.93±3.34) days,and 34.11±16.34 females and 11.04±8.87 males were produced by a mother.Sex ratio in offspring was female biased,and the proportion of male was 0.24±0.11.Developmental duration of the male parasitoids was shorter than that of the females.Proportion of male in offspring increased with the increase of oviposition duration,which suggested a depletion of sperm in the older females.Larger hosts were preferred when large and small hosts were available together.The length of hind tibia of males was smaller than that of females.Some fly pupae still emerged houseflies when superparasitism had been excluded and only once parasitism behavior had occurred.Body sizes of housefly pupae which produced female and male parasitoid adults were(11.38±3.20) mm3 and(9.02±3.06) mm3,respectively,and hosts sizes produced male parasitoid offspring were significantly smaller than those produced female offspring.Our results illuminated that the parasitoid preferred to lay more female eggs on larger hosts when superparasitism had been excluded.

无论在经济学或社会学界，以往有关发展学(development studies)的研究大多注重跨国资本流动和投资行为等宏观经济因素，同时强调行政制度和结构对发展中国家经济的影响。过去有关国际移民的研究不仅将人口跨国移动这一现象归咎于国家经济落后的原因，也同时视之为国家不发达的结果。近年来，对于移民国际汇款的研究开始注重微观的理论视角，强调移民个体和家庭的能动性。然而，这种在研究视角上的转变，对于研究国际移民与祖籍国发展的关系显然是不足的，因为它并没有考虑到移民群体自身所产生的组织和结构方面的效应，也没有考虑到在移民社团组织与祖籍国政府之间日益增长的交流，以及由此产生的促进发展的合力。本文的目的旨在深入探讨这一论题，通过对美国墨西哥裔和华裔两大移民社团的比较研究，描述移民与祖籍国 — 墨西哥和中国 — 墨西哥和的地区及国家层面的密切互动以及由此带来的发展。通过研究，我们发现移民跨国社团组织的成立和发展并不会使在国外永久定居的同胞完全放弃他们跟祖籍国的联系。相反的，那些在接收国已经取得较高社会地位以及在经济和法律上都得到保障的移民，更倾向于参与跨国活动，而移民个人跨国实践往往通过社团的方式来体现。现今交通工具的发达和便利，使永久迁移型的国际移民定期往返祖籍国的可能性大大增加，不仅扩展了跨国场域，也有利于他们在跨国场域中的施展，使他们身在国外也能参与祖籍国家乡的经济和社会生活，并为祖籍国汇入有形和无形的宝贵资源。对国际移民与祖籍国发展的因果进程进行系统的分析，有助于提出研究移民跨国主义的中层理论架构。本文还讨论了此项研究在实践和决策方面的启示。

早在欧洲殖民主义国家开始涉足亚洲大陆以前，华人就已飘洋过海，到亚洲和世界其他地方暂住或定居，以寻求谋生机会。现有超过3300万的华侨和华人在中国（包括香港、澳门及台湾）以外的地方生活，分布在全球151个国家，其中80%在亚洲，14%在美洲。本文旨在探讨华人国际移民悠久的历史和已经形成并正在不断发展的全球华人移民社会网络和侨乡网络与更高层次的结构性的因素（殖民地化与反殖民地化，民族国家的建立和国家政权更迭）之间的相互作用对华人移民所产生的影响。我认为从中国大陆涌出来的一波又一波的移民潮和这些移民在接收国的暂住或定居后的再移民，与历史有关，与母国和接收国的经济、接收国的华人社区和社群、全球华人移民社会网络等因素的互动有直接关系。这些宏观和微观的各种因素决定了华人国际移民的性质和发展历程。因此，目前中国和其他移民输出国所面临的挑战是如何去管理、引导和控制移民。然而，国家的这种能力面临着相当大的局限，一方面受制于经济原因，另一方面也受制于移民的广泛的社会网络、侨乡网络和海内外的各种社团组织。

Chronic lymphocytic leukaemia (CLL), which shares clinical and morphological overlap with small lymphocytic lyjmphoma (SLL), is a low-grade clonal B-cell lymphoproliferative disorder that accounts for 25% of all cases of leukaemia in Western countries, while it is considered rare in Oriental patients and is thought to constitute only 2% of all leukemias in these patients.[1] CLL is associated with an increased incidence of secondary malignant neoplasms, such as brain tumors, melanomas, and gastrointestinal-tract carcinomas[2]. However, the simulataneous occurrence of CLL and cutaneous squamous cell carcinoma (SCC) is rarely reported. We present here a case of CLL with multiple SCC on the face. Subsequent studies demonstrated the patient to have a trisomy 12 identified in bone marrow specimen.