鳖脾脏的正常组织学和病理组织学

鳖脾脏分为被膜和自由髓、红髓构成的实质，被膜较薄,小梁极不发达；白髓由动脉周围淋巴鞘构成，无淋巴小结；红髓由脾索和脾窦组成，脾窦不发达、病鳖脾脏的被膜血管肿胀；红髓淤血，白髓缩小并有红细胞存在，两者分界不清；病变严重的，脾内细胞坏死，呈无细胞结构状。     

美国判例法——商业外观“显著性”的判断与证明

2000年美国联邦最高法院Wal-mart v.Samara案的判决结果宣告商业外观显著性判断与证明标准问题暂告一段落。十年以来,下级法院的司法实践不断检验、冲击着Wal-mart v.Samara案所确立的＂商业外观应当区分商品包装和产品设计＂、＂产品设计天然不具有显著性＂及＂产品设计必须证明＇第二含义＇才可能获得法律保护＂等规则的正确性和可适用性。在商标法及反不正当竞争法的立法模式下,无论国内外,如何有效保护商业外观仍是一道难解的题。时值我国相关规则阙如之际,美国判例法形成的司法经验、留下的众多问题值得我国法制实践所参考。     

Evolutionary analyses of the human genome

The completion of the human genome will greatly accelerate the development of a new branch of science--evolutionary genomics. We can now directly address important questions about the evolutionary history of human genes and their regulatory sequences. Computational analyses of the human genome will reveal the number of genes and repetitive elements, the extent of gene duplication and compositional heterogeneity in the human genome, and the extent of domain shuffling and domain sharing among proteins. Here we present some first glimpses of these features.     

Demography of the endangered North Atlantic right whale.

Northern right whales (Eubalaena glacialis) were formerly abundant in the northwestern Atlantic, but by 1900 they had been hunted to near extinction. After the end of commercial whaling the population was thought to be recovering slowly; however, evidence indicates that it has been declining since about 1990 (ref. 1). There are now fewer than 300 individuals, and the species may already be functionally extinct owing to demographic stochasticity or the difficulty of females locating mates in the vast Atlantic Ocean (Allee effect). Using a data set containing over 10,000 sightings of photographically identified individuals we estimated trends in right whale demographic parameters since 1980. Here we construct, using these estimates, matrix population models allowing us to analyse the causes of right whale imperilment. Mortality has increased, especially among mother whales, causing declines in population growth rate, life expectancy and the mean lifetime number of reproductive events between the period 1980-1995. Increased mortality of mother whales can explain the declining population size, suggesting that the population is not doomed to extinction as a result of the Allee effect. An analysis of extinction time shows that demographic stochasticity has only a small effect, but preventing the deaths of only two female right whales per year would increase the population growth rate to replacement level.     

Low-coverage vaccination strategies for the conservation of endangered species

The conventional objective of vaccination programmes is to eliminate infection by reducing the reproduction number of an infectious agent to less than one, which generally requires vaccination of the majority of individuals. In populations of endangered wildlife, the intervention required to deliver such coverage can be undesirable and impractical; however, endangered populations are increasingly threatened by outbreaks of infectious disease for which effective vaccines exist. As an alternative, wildlife epidemiologists could adopt a vaccination strategy that protects a population from the consequences of only the largest outbreaks of disease. Here we provide a successful example of this strategy in the Ethiopian wolf, the world's rarest canid, which persists in small subpopulations threatened by repeated outbreaks of rabies introduced by domestic dogs. On the basis of data from past outbreaks, we propose an approach that controls the spread of disease through habitat corridors between subpopulations and that requires only low vaccination coverage. This approach reduces the extent of rabies outbreaks and should significantly enhance the long-term persistence of the population. Our study shows that vaccination used to enhance metapopulation persistence through elimination of the largest outbreaks of disease requires lower coverage than the conventional objective of reducing the reproduction number of an infectious agent to less than one.     

特有种四合木种群遗传结构分析

对四合木种群的遗传结构进行了研究．结果表明，四合木在种群水平上维持较高的遗传多样性．大部分遗传多样性存在于种群内，种群间的遗传分化很低．四合木的较高的遗传多样性是在长期进化过程中适应生境条件变化形成的．其基因组DNA存在较高的变异性，各种群之间存在一定的基因流，四合木各种群可看成是meta-种群，应注意保护四合木中具有丰富的遗传多样性的meta-种群．     

珍稀濒危蕨类植物金毛狗的研究进展

金毛狗是蚌壳蕨科金毛狗属的大型树状蕨类,是重要的药用植物。近年来,由于生态环境的恶化及人为活动频繁等因素的影响,野生资源数量大大减少,已被列入国家二级保护植物。本文就金毛狗形态特征、孢子体及配子体发育、遗传多样性等方面进行综述,以期为濒危蕨类金毛狗的科学保护及合理的开发利用提供理论依据。     

鳖疖疮病的组织病理研究

鳖疖疮病的组织病理研究①颜素芬江福来（集美大学水产学院养殖系厦门３６１０２１）随着我国养鳖业的迅速发展，鳖（Ｔｒｉｏｎｇｘｓｉｎｅｎｓｉｓ）的病害也日渐增多并趋严重．有关鳖病的研究，日本［１，２］和我国［３～６］虽然在病原和防治方面陆续有文章报道，但...     

精神分裂症起因的进化生物学分析

精神分裂症受基因因素,自然环境因素以及心理应激因素等多种因素共同影响,但目前多数研究都只关注于其中一项,很少有假说能兼顾各种因素.针对精神分裂症研究的这种局限,从进化的角度,利用达尔文医学和进化心理学的方法对精神分裂症进行剖析,以推测其可能的进化史因,并解释环境因素与遗传因素等在精神分裂症发生发展中的作用.同时,对影响精神分裂症发病率的多种环境因素进行了分析,并讨论了精神分裂症的性别特异性、年龄特异性等发病特性,在此基础上提出和论证了一个新的精神分裂症病因的理论假说:"精神分裂症相关基因是一组用于应对不利生存环境的基因,受环境因素的反馈控制.当环境过于恶劣时,这些基因的过度表达就会引发精神分裂症."     

武功山珍稀濒危植物资源及其区系特征

在野外调查的基础上,以《中国植物红皮书》（第一册）和1999年由国务院批准公布的《国家重点保护野生植物名录（第一批）》等为依据,武功山有国家保护珍稀濒危植物共计35科52属68种。本文对上述珍稀保护植物的生活型及其区系特征进行调查和分析,结果表明：该区分布的52属珍稀濒危植物中,热带分布型有16属,占种子植物属的30．77％,温带分布型有20属,占38．46％,其植物区系具有明显的温带——亚热带过渡性质;中国特有分布型15属,占总属数的28．85％,具有特有性强,起源古老的特征。     

演化经济学发展历程

对演化经济学发展的历程进行了简要回顾，并对其前沿问题作了简要介绍。