1,720,988 research outputs found
Exploring and validating statistical reliability in forensic conservation genetics
Full text linkSafeguarding biological diversity from evolutionary lineages to ecosystems is a major undertaking for humanity. Forensic conservation genetics for the protection of wild flora and fauna aims to provide statistical inference tools and services for the enforcement of local to global conservation and management strategies. This paper reviews statistical criteria that provide insight into and assess the reliability of conclusions drawn from statistical inference. The translation of these fundamental criteria into practice is illustrated with applications from evolutionary and forensic genetics, specifically focusing on the inference of geographic origin using population assignment approaches. [...]Der Schutz biologischer Vielfalt von evolutionären Linien bis hin zu Ökosystemen ist eines der wichtigsten Unterfangen der Menschheit. Forensische Erhaltungsgenetik zum Schutz wilder Flora und Fauna hat das Ziel Werkzeuge und Dienstleistungen für statistische Schlussfolgerungen zur Ausübung und Durchsetzung von lokalen bis globalen Erhaltungs- und Bewirtschaftungsstrategien bereitzustellen. Die vorliegende Arbeit gibt einen Überblick über statistische Kriterien, welche Einblick in und eine Bewertungsgrundlage für die Verlässlichkeit von Schlussfolgerungen geben, welche auf Grund von statistischen Inferenzverfahren gezogen wurden. Die Überführung dieser grundlegenden Kriterien in die Anwendung wird durch ihren Einsatz in der Evolutions- und Erhaltungsgenetik illustriert, wobei der Fokus speziell auf der Rekonstruktion der geographischen Herkunft durch Zuordnungsverfahren auf Populationsebene liegt. [...
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
Identification of single nucleotide polymorphisms in differentPopulusspecies
No full textPartial sequences of six genes in 54 trees belonging to five different Populus species were analyzed for occurrence of single nucleotide polymorphisms (SNPs). Genes selected are involved in wood formation and quality (CAD), defence reactions (PPO), hormone biosynthesis (GA20ox), or transcription factors (CBF1, TB1, LFY). The number of polymorphisms identified for each gene fragment varied between different genes, and also between exon and intron regions. The six genes resolved the phylogenetic relationships between the five species to different degrees. Only PPO is resolving all five Populus species as monophyletic in all three phylogenetic approaches. CAD resolves all species with the exception of Populus tremula. For CBF1 and TB1, a monophyletic group consisting of P. tremula and P. tremuloides is resolved by some of the reconstruction approaches. Indels in three out of the six genes analyzed were detected in consensus-sequence comparisons between the Populus species. In the CAD-like and LFY genes, these were found only in introns but in the case of TB1 gene these were also found in coding regions. Sizes of the indels range from 1 up to 8 nucleotides. This study confirms the main split between section Leuce and a group-combining sections Aigeiros and Tacamahaca that is perfectly supported with 100% bootstrap supports and 1.0 posterior probability. The SNP markers developed as well as the indels identified can be used for differentiation of Populus species and characterization of hybrids
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
(lichen‐forming Ascomycota)
No full textHistorical and contemporary geographical distribution ranges with their associated gene flow patterns interact to produce the genetic diversity observed today. Often it is not possible to separate out the impacts of historical events, e.g. past fragmentation, and contemporary gene flow, e.g. long-distance dispersal. Porpidia flavicunda is a lichen-forming ascomycete occurring circumpolar in the boreal to arctic zones for which vegetation history suggests that its distribution pattern has stayed broadly the same over the past millennia. DNA-sequence diversity in P. flavicunda can, thus, be expected to predominantly represent geographical population differentiation and its contemporary migration rates. The population sample consists of 110 specimens collected in Northern Québec, Baffin Island, Western Greenland and Northern Scandinavia. DNA-sequence data sets of three nuclear gene fragments (LSU, RPB2 and ß-tubulin) were analysed for genetic diversity within, and differentiation between, geographical regions. Tests of population subdivision employing analyses of molecular variance and exact tests of haplotype frequency distributions showed significant structure between the geographical regions. However, the lack of fixed nucleotide polymorphisms and the wide sharing of identical haplotypes between geographical regions suggest recurrent long-distance gene flow of propagules. Still, the means by which propagules are dispersed remain to be discovered. Inference of migration rates shows that in many cases a sufficiently high amount of migrants is exchanged between geographical regions to prevent drastic population differentiation through genetic drift. The observed haplotype distributions and migration rates point to a gene flow model of isolation by distance
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
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