28 resultados para Modern literature

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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We investigated the distribution of Y-chromosome haplotype using 19 Y-SNPs in Han Chinese populations from 22 provinces of China. Our data indicate distinctive patterns of Y chromosome between southern and northern Han Chinese populations. The southern po

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East Asia is one of the few regions in the world where a large number of human fossils have been unearthed. The continuity of hominid fossils in East Asia, particularly in China has been presented as strong evidence supporting an independent origin of mod

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To test the hypotheses of modern human origin in East Asia, we sampled 12,127 male individuals from 163 populations and typed for three Y chromosome biallelic markers (YAP, M89, and M130). All the individuals carried a mutation at one of the three sites.

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Background: The phylogeography of the Y chromosome in Asia previously suggested that modern humans of African origin initially settled in mainland southern East Asia, and about 25,000 30,000 years ago, migrated northward, spreading throughout East Asia. H

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During the course of evolution, the human skeletal system has evolved rapidly leading to an incredible array of phenotypic diversity, including variations in height and bone mineral density. However, the genetic basis of this phenotypic diversity and the relatively rapid tempo of evolution have remained largely undocumented. Here, we discover that skeletal genes exhibit a significantly greater level of population differentiation among humans compared with other genes in the genome. The pattern is exceptionally evident at amino acid-altering sites within these genes. Divergence is greater between Africans and both Europeans and East Asians. In contrast, relatively weak differentiation is observed between Europeans and East Asians. SNPs with higher levels of differentiation have correspondingly higher derived allele frequencies in Europeans and East Asians. Thus, it appears that positive selection has operated on skeletal genes in the non-African populations and this may have been initiated with the human colonization of Eurasia. In conclusion, we provide genetic evidence supporting the rapid evolution of the human skeletal system and the associated diversity of phenotypes.

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把1870-2001年来自美国"现代灵长类文献题录数据库"、"维普中文数据库"及"中国灵长类研究文献题录"的资料按4个时期(I:1870-1949;Ⅱ:1950-1965;Ⅲ:1966-1977;Ⅳ:1978-2001)分类整理.此外,使用了"科学引文数据库(扩展版)".结果如下:(1)1870-2001年共有20 52篇文献,2个文献数量高峰分别出现于1950-1965和1978-2001年;科研部门所发表的论文占54.2%,并随时间而增加;而国外部门则随之减少.(2)2 052篇文献中,超过9%的文献为SCI所收录,其中1966-1977年被SCI收录的文献百分比最高;在全部被SCI收录的文献中又以科研部门的占优势(59.1%);但国外部门则以其30.1%的文献被SCI收录而领先.(3)统计了灵长类研究9个领域文献百分比及其变化,其中1978-2001间生态学和行为、神经生物学、繁殖和饲养快速发展;化石灵长类、形态学和解剖学减少;分类及分布、细胞及分子进化显得不甚突出;在第Ⅱ时期和第Ⅳ时期疾病防治研究相当多;保护生物学得到越来越多的关注.第Ⅳ时期作者数量最多,但每个作者的文献平均数却不如第Ⅰ时期.一般地说,在SCI收录的作者中以中国作者居多,但在第I时期唯一被SCI收录的作者则是一名外国学者;在第Ⅲ时期外国作者占被收录作者数的60%.

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Goal, Scope and Background. In some cases, soil, water and food are heavily polluted by heavy metals in China. To use plants to remediate heavy metal pollution would be an effective technique in pollution control. The accumulation of heavy metals in plants and the role of plants in removing pollutants should be understood in order to implement phytoremediation, which makes use of plants to extract, transfer and stabilize heavy metals from soil and water. Methods. The information has been compiled from Chinese publications stemming mostly from the last decade, to show the research results on heavy metals in plants and the role of plants in controlling heavy metal pollution, and to provide a general outlook of phytoremediation in China. Related references from scientific journals and university journals are searched and summarized in sections concerning the accumulation of heavy metals in plants, plants for heavy metal purification and phytoremediation techniques. Results and Discussion. Plants can take up heavy metals by their roots, or even via their stems and leaves, and accumulate them in their organs. Plants take up elements selectively. Accumulation and distribution of heavy metals in the plant depends on the plant species, element species, chemical and bioavailiability, redox, pH, cation exchange capacity, dissolved oxygen, temperature and secretion of roots. Plants are employed in the decontamination of heavy metals from polluted water and have demonstrated high performances in treating mineral tailing water and industrial effluents. The purification capacity of heavy metals by plants are affected by several factors, such as the concentration of the heavy metals, species of elements, plant species, exposure duration, temperature and pH. Conclusions. Phytoremediation, which makes use of vegetation to remove, detoxify, or stabilize persistent pollutants, is a green and environmentally-friendly tool for cleaning polluted soil and water. The advantage of high biomass productive and easy disposal makes plants most useful to remediate heavy metals on site. Recommendations and Outlook. Based on knowledge of the heavy metal accumulation in plants, it is possible to select those species of crops and pasturage herbs, which accumulate fewer heavy metals, for food cultivation and fodder for animals; and to select those hyperaccumulation species for extracting heavy metals from soil and water. Studies on the mechanisms and application of hyperaccumulation are necessary in China for developing phytoremediation.