1,720,970 research outputs found
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
Dynamics of inbreeding and genetic rescue in a small population
No full textIsolation at small population size can reduce individual fitness and impede population growth caused by inbreeding and genetic drift (i.e. inbreeding depression). Inbreeding depression can however be circumvented by gene flow from unrelated individuals through masking of recessive deleterious alleles and contribute to population persistence (i.e. genetic rescue). Studying these processes in natural populations across generations and under fluctuating environmental conditions however comes with major challenges. Several gaps in the knowledge thus remain regarding causes and consequences of inbreeding depression and genetic rescue in the wild. Using long term data on life history traits, combined with traditional population genetics and novel genomic techniques, we explored the dynamics of inbreeding and gene flow in the highly fragmented arctic fox (Vulpes lagopus) population in Sweden. This thesis mainly focused on the southernmost subpopulation (Helagsfjällen), previously documented to suffer from inbreeding depression. Construction of a genetically verified pedigree (Chapter I and II) revealed that gene flow from three outbred male foxes released from a captive breeding station in Norway resulted in genetic rescue, expressed as elevated first year survival and breeding success in immigrant first generation offspring (F1; Chapter I). However, the rescue effect likely only lasted for one single generation, as we found no selective advantage in later descendants of immigrants (Chapter II and IV). Whole genome sequencing of a subset of individuals from the same subpopulation showed that some immigrant F2 and F3 individuals were highly inbred despite the recent outbreeding events (Chapter III). Identification of putative deleterious variation within coding regions suggested that the immigrants introduced a large number of strongly deleterious alleles which were absent from the native gene pool (Chapter IV and V). Expression of the deleterious variation introduced may explain the low persistence of genetic rescue. We also found a negative relationship between the amount of homozygous strongly deleterious mutations and individual fitness (Chapter IV) and may be an important cause of inbreeding depression in the Swedish arctic fox. Finally, when replicating the study of genomic consequences of inbreeding and gene flow, by including an additional Swedish subpopulation (Vindelfjällen) located further north, we found contrasting patterns between the two subpopulations. While inbreeding decreased in both Helagsfjällen and Vindelfjällen following immigration, the proportion of deleterious variation increased in Helagsfjällen but not in Vindelfjällen. A potential explanation could be more regular gene flow between northern located subpopulations compared to the more geographically isolated population in Helagsfjällen, which may instead have purged a subset of strongly deleterious variation pre immigration. The results from this thesis highlight the transient nature of genetic rescue and the importance to study fitness and genetic effects of gene flow across several generations, as immigration could have negative consequences that are not manifested initially. Finally, as the effects of gene flow can be highly context dependent, demographic histories and functional genetic variation in both source and target populations should be considered before making translocation decisions for conservation purposes
Strongly deleterious mutations influence reproductive output and longevity in an endangered population
No full textGenomic consequences of reintroductions from a captive breeding station - a replicated evaluation
No full textkoamabayili/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
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