1,720,976 research outputs found
What can chromosomes tell us about the origins of primates?
No full textWhat can chromosomes tell us about the origins of primates?
Barbara Picone1, Luca Sineo1, Daniele Silvestro2,3, Massimiliano DelPero4 and Judith Masters5
1 Dipartimento di Biologia Animale “G. Reverberi”, Università degli Studi di Palermo, Via Archirafi 18, 90123 Palermo, Italy; 2 Senckenberg Research Institute, Frankfurt am Main, Germany ; 3 Biodiversity and Climate Research Centre (BiK-F), Frankfurt am Main, Germany;4 Dipartimento di Biologia Animale e dell’Uomo, Università degli Studi di Torino, Via Accademia Albertina 13, 10124 Torino, Italy; 5Department of Zoology and Entomology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa;
Our study investigated the usefulness of chromosome painting data in analysing phylogenetic affinities among the orders included in Euarchontoglires (Primates, Rodentia, Scandentia, Lagomorpha and Dermoptera). We applied Maximum Parsimony and Baysian inference in the comparison of karyotypic similarities and differences visualised among 41 Euarchontaglires species and one monotreme outgroup. In total, 161 characters were identified on the basis of presence/absence of human orthologous segmental associations. The inclusion of this large sample covering a wide phylogenetic spectrum revealed that some syntenies previously reported as synapomorphic are in fact homoplastic traits. The high levels of homoplasy reflected in our data suggest that the same associations occur repeatedly. Karyotype evolution is relatively rapid, making it more informative about shallow rather than deep divergences
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
A Phylogenetic Analysis of Human Syntenies Revealed by Chromosome Painting in Euarchontoglires Orders
No full textPhylogenetic relationships among the Lorisoidea as indicated by craniodental morphology and mitochondrial sequence data
No full textDispelling 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
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