Chinese science citation database opens to worldwide users

National Science Library,Chinese Acad-emy of Sciences(CAS)launched its Chi-nese Science Citation Database(CSCD)at the Science Communication and Self-innovation Forum held in Beijing.CSCD based itself on the ISI     

High plant diversity is needed to maintain ecosystem services

Biodiversity is rapidly declining worldwide, and there is consensus that this can decrease ecosystem functioning and services. It remains unclear, though, whether few or many of the species in an ecosystem are needed to sustain the provisioning of ecosystem services. It has been hypothesized that most species would promote ecosystem services if many times, places, functions and environmental changes were considered; however, no previous study has considered all of these factors together. Here we show that 84% of the 147 grassland plant species studied in 17 biodiversity experiments promoted ecosystem functioning at least once. Different species promoted ecosystem functioning during different years, at different places, for different functions and under different environmental change scenarios. Furthermore, the species needed to provide one function during multiple years were not the same as those needed to provide multiple functions within one year. Our results indicate that even more species will be needed to maintain ecosystem functioning and services than previously suggested by studies that have either (1) considered only the number of species needed to promote one function under one set of environmental conditions, or (2) separately considered the importance of biodiversity for providing ecosystem functioning across multiple years, places, functions or environmental change scenarios. Therefore, although species may appear functionally redundant when one function is considered under one set of environmental conditions, many species are needed to maintain multiple functions at multiple times and places in a changing world.     

科学为何保守?

传统的认识将科学描绘为思想上的创新和自由,这主要是因为科学乐于考虑所有的想法和观点。但在另一种意义上,科学是非常保守的。真正新颖的认识只会偶尔出现,而要被人们接受往往还要经过大量的努力和斗争。事实上,这并不是坏事,而是科学应有的方式。     

实验动物科学技术是生命科学和健康中国建设的基础支撑条件

 实验动物科学技术是生命科学、医学创新研究的重要组成部分和可持续发展的重要支撑平台,是“创新型国家”的战略资源之一,对保障人类健康、食品安全、生物安全等都具有重要的战略意义。中国实验动物科学技术经过几十年的发展,建立了包括实验动物法律、法规、标准等在内的管理体系;形成了科学研究、生产供应、质量保障和人才培养体系;建成了十余个国际水平的实验动物技术平台。本文通过阐述中国实验动物科学技术发展现状,找出存在问题,提出加快中国实验动物科学技术创新发展的重大建议,为生命科学和健康中国建设奠定基础。     

The Ph1 locus is needed to ensure specific somatic and meiotic centromere association

The correct pairing and segregation of chromosomes during meiosis is essential for genetic stability and subsequent fertility. This is more difficult to achieve in polyploid species, such as wheat, because they possess more than one diploid set of similar chromosomes. In wheat, the Ph1 locus ensures correct homologue pairing and recombination. Although clustering of telomeres into a bouquet early in meiosis has been suggested to facilitate homologue pairing, centromeres associate in pairs in polyploid cereals early during floral development. We can now extend this observation to root development. Here we show that the Ph1 locus acts both meiotically and somatically by reducing non-homologous centromere associations. This has the effect of promoting true homologous association when centromeres are induced to associate. In fact, non-homologously associated centromeres separate at the beginning of meiosis in the presence, but not the absence, of Ph1. This permits the correction of homologue association during the telomere-bouquet stage in meiosis. We conclude that the Ph1 locus is not responsible for the induction of centromere association, but rather for its specificity.