文章选取www.altmetric.com上2016-2018年Altmetrics TOP100论文的相关指标数据以及对应的Web of Science论文被引频次为数据源,运用VOSviewer、Spss和Python对每年Altmetrics TOP100论文的来源机构、来源期刊、所属学科及传播途径展开...文章选取www.altmetric.com上2016-2018年Altmetrics TOP100论文的相关指标数据以及对应的Web of Science论文被引频次为数据源,运用VOSviewer、Spss和Python对每年Altmetrics TOP100论文的来源机构、来源期刊、所属学科及传播途径展开探究。研究结果表明,Altmetrics TOP100论文主要来自于欧美发达国家的高水平研究机构和关于医疗与健康科学领域的高影响因子的期刊。Twitter作为传播高影响力论文的首选途径,通过与其他传播途径相结合,进一步提高了论文的社会影响力。展开更多
The purpose of the present paper is to study and develop indicators and procedures for the evaluation of genetic structure changes in germplasm conservation due to social and natural environment reasons. Some basic ...The purpose of the present paper is to study and develop indicators and procedures for the evaluation of genetic structure changes in germplasm conservation due to social and natural environment reasons. Some basic concepts in germplasm study were introduced at first. Then, six kinds of indicators for genetic diversity as a measure of genetic potential of a germplasm collection were presented, i.e., numbers of different entities at certain level, evenness of the entity distribution, genetic similarity and genetic distance, genetic variance and genetic coefficient of variation, multivariate genetic variation indices, and coefficient of parentage. It was pointed out that genetic dispersion did not provide a complete concept of genetic diversity if without any information from genetic richness. Based on the above, the indicators for genetic erosion as the genetic structure changes of germplasm conservation due to social reasons, the indicators of genetic vulnerability as the genetic structure changes of germplasm conservation due to environmental stresses, the measurement of genetic drift and genetic shift as the genetic structure changes of germplasm collection during reproduction or seed increase were reviewed and developed. Furthermore, the estimation procedures of the indicators by using molecular markers were suggested. Finally, the case studies on suitable conservation sample size of self-pollinated and open-pollinated populations were given for reference.展开更多
基金supported by the National Natural Science Foundation of China(30270805 and 30490250)Doctorate Foundation of Higher Education(20020307028).
文摘The purpose of the present paper is to study and develop indicators and procedures for the evaluation of genetic structure changes in germplasm conservation due to social and natural environment reasons. Some basic concepts in germplasm study were introduced at first. Then, six kinds of indicators for genetic diversity as a measure of genetic potential of a germplasm collection were presented, i.e., numbers of different entities at certain level, evenness of the entity distribution, genetic similarity and genetic distance, genetic variance and genetic coefficient of variation, multivariate genetic variation indices, and coefficient of parentage. It was pointed out that genetic dispersion did not provide a complete concept of genetic diversity if without any information from genetic richness. Based on the above, the indicators for genetic erosion as the genetic structure changes of germplasm conservation due to social reasons, the indicators of genetic vulnerability as the genetic structure changes of germplasm conservation due to environmental stresses, the measurement of genetic drift and genetic shift as the genetic structure changes of germplasm collection during reproduction or seed increase were reviewed and developed. Furthermore, the estimation procedures of the indicators by using molecular markers were suggested. Finally, the case studies on suitable conservation sample size of self-pollinated and open-pollinated populations were given for reference.
