1,720,975 research outputs found
Mediterranean Y-chromosome 2.0why the Y in the Mediterranean is still relevant in the postgenomic era
No full textContext: Due to its unique paternal inheritance, the Y-chromosome has been a highly popular marker among population geneticists for over two decades. Recently, the advent of cost-effective genome-wide methods has unlocked information-rich autosomal genomic data, paving the way to the postgenomic era. This seems to have announced the decreasing popularity of investigating Y-chromosome variation, which provides only the paternal perspective of human ancestries and is strongly influenced by genetic drift and social behaviour.Objective: For this special issue on population genetics of the Mediterranean, the aim was to demonstrate that the Y-chromosome still provides important insights in the postgenomic era and in a time when ancient genomes are becoming exponentially available.Methods: A systematic literature search on Y-chromosomal studies in the Mediterranean was performed.Results: Several applications of Y-chromosomal analysis with future opportunities are formulated and illustrated with studies on Mediterranean populations.Conclusions: There will be no reduced interest in Y-chromosomal studies going from reconstruction of male-specific demographic events to ancient DNA applications, surname history and population-wide estimations of extra-pair paternity rates. Moreover, more initiatives are required to collect population genetic data of Y-chromosomal markers for forensic research, and to include Y-chromosomal data in GWAS investigations and studies on male infertility
Temporal differentiation across a West-European Y-chromosomal cline: genealogy as a tool in human population genetics
No full textThe pattern of population genetic variation and allele frequencies within a species are unstable and are changing over time according to different evolutionary factors. For humans, it is possible to combine detailed patrilineal genealogical records with deep Y-chromosome (Y-chr) genotyping to disentangle signals of historical population genetic structures because of the exponential increase in genetic genealogical data. To test this approach, we studied the temporal pattern of the 'autochthonous' micro-geographical genetic structure in the region of Brabant in Belgium and the Netherlands (Northwest Europe). Genealogical data of 881 individuals from Northwest Europe were collected, from which 634 family trees showed a residence within Brabant for at least one generation. The Y-chr genetic variation of the 634 participants was investigated using 110 Y-SNPs and 38 Y-STRs and linked to particular locations within Brabant on specific time periods based on genealogical records. Significant temporal variation in the Y-chr distribution was detected through a north-south gradient in the frequencies distribution of sub-haplogroup R1b1b2a1 (R-U106), next to an opposite trend for R1b1b2a2g (R-U152). The gradient on R-U106 faded in time and even became totally invisible during the Industrial Revolution in the first half of the nineteenth century. Therefore, genealogical data for at least 200 years are required to study small-scale 'autochthonous' population structure in Western Europe
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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