125 research outputs found
Haploid genetic variation in populations from Uganda, Zambia and the Central African Republic
A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the Degree of Doctor of Philosophy.Y chromosome DNA and mitochondrial DNA (mtDNA) variation were examined in Ugandans, Zambians, Biaka Pygmies and non-Pygmies from the Central African Republic. Y chromosome DNA variation was also examined in populations from the Democratic Republic of Congo. Data generated in this study were analysed together with published data to (1) clarify the understanding of the overall patterns of haploid genetic variation in Africa; (2) examine genetic affinities among central African and other African populations; (3) assess the concordance of haploid markers with different mutation rates in assessing population affinities; (4) compare male and female migration rates in African populations; and (5) refine theories regarding the prehistory of central Africa populations based on linguistics and archaeology.
Sixteen biallelic and eight microsatellite Y-specific markers were examined in 369 central African individuals. Eleven Y chromosome haplogroups (HGs A, B*, B-M150, B-Ml 12, B- M211, E-M191, E-M2, E-M35, E-M40, FJ and R) and 174 compound haplotypes were identified. The mtDNA 9-bp deletion, 3592 Hpal and 10397 Alul restriction polymorphisms, and two hypervariable regions (HVRs) were examined in 397 individuals. A total of 246 mtDNA types were identified and classified into 19 mtDNA subhaplogroups.
Using Y chromosome data, central African populations shared close genetic affinities with each other and with populations from west and southern Africa. Extensive unidirectional Y chromosome gene flow from non-Pygmy populations to Biaka Pygmies was observed. Using mtDNA data, central African non-Pygmy populations shared close genetic affinities with each other and with populations from west, east and southern Africa. MtDNA studies indicated almost complete maternal genetic isolation of Biaka. Overall, using both mtDNA and Y chromosome data, pan-African populations were best grouped by geographic rather than by linguistic criteria.
Different mtDNA and Y chromosome data types revealed similar genetic relationships among African populations. Female migration rates appear to have exceeded male migration rates in non-Pygmy central African populations in this study, whilst the opposite was found in Biaka Pygmies. Data types at different levels of resolution suggested that male and female migration rates in Africa may have differed over time, and may not have been significantly different. This research has provided new insights into the complex demographic history that shaped the present-day genetic landscape of central African populations.WHSLYP201
Iranian Authors\u27 Contributions to the Library Philosophy and Practice
Objective: This study aimed to conduct a bibliometric analysis and scientific visualization of the contribution made by Iranians\u27 authors in the Library Philosophy and Practice (LPP) from 2006 to 2019.
Material and Methods: This bibliometric analysis used Scopus database for retrieving data on all papers published by Iranians in LPP during the study time span. VOSviewer and Microsoft Excel software packages were used for data analysis.
Findings: Out of 139 papers authored by Iranians in LPP, the first published paper belonged to 2006. An increasing trend can be seen in annual publication number, with 1 and 64 papers in 2007 and 2019, respectively. The first ranked active author was Khasseh A.A. with 9 papers. Shahid Beheshti University of Medical Sciences and Payame Noor University were in the top of the contributing institutes, each with authoring 20 papers followed by Islamic Azad University, Central with 13 papers. Iranian more collaborated with Indians. The mean rate of received citations per paper was 0.62. The top three highly-cited authors were Isfandyiari-Moghaddam, A. (with 13), Khasseh A.A. and Saberi M.K. (each with 11) and Biranvand (with 10), respectively. Citing some known journals in their papers, Iranian researchers considered main topics in LIS field, including bibliometrics, altmetrics and library management and technologies.
Conclusion: This study is a relatively comprehensive bibliometric analysis of Iranians\u27 contributions to LPP. The result can be helpful as a road map for researchers and readers countrywide as well as the editorial team of the journal
Publication Performance and Trends in Altmetrics: A Bibliometric Analysis and Visualization
Bibliometric analysis of different fields of knowledge leads to a better understanding of the trend and quality of scientific products. The present study examined the publications on Altmetrics through bibliometric analysis and knowledge mapping. In this survey research, using quantitative indicators of scientometric, scientific developments in the field of altmetrics have been evaluated. The study population included all articles in the field of altmetrics (1077 documents) indexed in the Scopus database from the beginning to the end of 2020. The Excel and VOSviewer software packages were used to analyze the data. The findings show that scientific products in the field of altmetrics indexed in Scopus have been published since 2012; the quantitative trend of publications has been upward; Most of the scientific products in the field of altmetrics were original articles and in English. The United States, the United Kingdom, and Spain were the top and most productive countries in publishing documents in the field. Iran was ranked ninth with 52 documents. Regarding the number of publications, the University of Wolverhampton, the Administrative Headquarters of the Max Planck Society, and Leiden University were ranked first to third, respectively. Thelwall, M., with 42 articles, Bornmann, L., with 32 articles, and Haunschild, R., with 25 articles, were the most active authors. The most frequently used keywords were "Altmetrics", "bibliometrics" and "Social media". The highest number of documents in the field of Altmetrics has been published in the journal "Scientometrics". The most cited author was Thelwall, M., with 2691 citations. Due to the upward trend of scientific publications in Altmetrics and the beginning of its way, this upward trend will continue. Also, most of the top authors in the field are from universities and countries active in this field
A Bibliometric Study and Visualization of Library Philosophy and Practice during 1998-2018
Purpose- The purpose of this paper is to analyze bibliometrics and visualization of Library Philosophy and Practice (LPP).
Design/methodology/approach- Scopus citation database was used to gather the data. Using advanced search in the database, bibliographic data of the articles published in the journal over the past twenty years were extracted. Then, the analysis was performed using bibliometric indicators and some applications, such as Microsoft Excel and VOS viewer.
Findings- The data indicated that the process of publications (R²=0.69) and citations received by papers (R²=0.85) was ascending. The paper of W. Fang (2007), Using Google analytics for improving library website content and design: A case study , is the most highly cited paper of LPP. Bhatti, R. (19 papers), Nigeria (549 papers), University of Ibadan (78 papers) are the most productive and influential authors, universities, and countries in LPP, respectively. Keyword clustering of published papers indicates that the most frequent keywords can fall into five clusters and the first and most important cluster is bibliometrics study . In addition, the analysis of references of LPP articles showed that Library Philosophy and Practice Scientometrics , and The Electronic Library are the top journals, Aina, I., Wilson, T.D.O., and Mahmood, K. are the top authors cited in LPP.
Practical implications- The bibliometrics analysis and LPP visualization can be a useful for either library and information science (LIS) scholars or the people interested in bibliometric studies; therefore, they can use it as a pattern to review other journals.
Originality/value- This study suggests a general outlook for the performance of an international LIS journal using bibliometric indicators and visualization. The results of this study will be beneficial for all the LIS authors and researchers around the world.
Keywords: Bibliometric analysis, Visualization, Citation analysis, VOS viewer, Scopus
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