1,721,044 research outputs found
Diversification history and morphological evolution of larks
No full textEcomorphological and biogeographical data for all lark species included in the study.R code employed to conduct the analyses. Please, note that we did not incorporate in the manuscript all analyses explored in the R script; in some cases, we built similar models using different approaches and R packages (‘PANDA’, ‘DDD’, ‘laser’, ‘diversitree’) to test the consistency of our results. Thus, this is not an exhaustive set of code but serves to demonstrate the approaches employed in this study.Peer reviewe
Diversification history and morphological evolution of larks
No full textLarks (Alaudidae) constitute one of the avian families best adapted to xeric environments, having colonized a wide suite of open habitats including deserts. Although their highest diversity is in Africa, larks occur on all nonpolar continents. We tested whether larks exhibit exceptional and/or correlated shifts in the tempos of speciation and ecological trait diversification in the face of open ecological space. We employed a near-complete phylogeny and a morphological dataset including several recently recognized species. We found homogeneity in diversification dynamics across the family and evidence for a diversity‐dependent slowdown in cladogenesis, which indicates that Alaudidae may approach their ‘ecological limit’. We did not observe an early burst in phenotypic diversification, as would be expected in a ‘classic’ adaptive radiation. Our findings suggest that the morphology of larks shows a high level of evolutionary conservatism and overall lack of ecomorphological convergence: ecological variables (diet and habitat)—which by contrast display a higher lability—explain little of shape/size variation except beak shape. Both adaptation to aridity and dietary transitions have evolved independently in multiple lineages across subfamilies. This study supports the idea that continental radiations in open habitats may reach an equilibrium faster than those in tropical forests, due to differences in ecological opportunities.V.G.N. was supported by the ‘Ramón y Cajal’ programme (ref. RYC2019-026703-I) and the research project COMEVO (ref. PID2021-123304NA-I00) of the Spanish Ministry of Science and Innovation. P.A. was supported by the National Swedish Research Council (grant No. 2019-04486) and the Jornvall Foundation.Peer reviewe
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
Avian Island Radiations Shed Light on the Dynamics of Adaptive and Nonadaptive Radiation
No full textUnderstanding the mechanisms underlying species formation and differentiation is a central goal of evolutionary biology and a formidable challenge. This understanding can provide valuable insights into the origins of the astonishing diversity of organisms living on our planet. Avian evolutionary radiations on islands have long fascinated biologists as they provide the ideal variation to study the ecological and evolutionary forces operating on the continuum between incipient lineages to complete speciation. In this review, we summarize the key insights gained from decades of research on adaptive and nonadaptive radiations of both extant and extinct insular bird species. We present a new comprehensive global list of potential avian radiations on oceanic islands, based on published island species checklists, taxonomic studies, and phylogenetic analyses. We demonstrate that our understanding of evolutionary processes is being greatly enhanced through the use of genomic tools. However, to advance the field, it is critical to complement this information with a solid understanding of the ecological and behavioral traits of both extinct and extant avian island species.Peer reviewe
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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