1,720,966 research outputs found
Characterization of a MuSashI-like transcript in a colonial chordate, phylogenetic analysis of the protein group and differential expression patterns in sexual versus asexual development.
No full textTunicates are the unique chordates to possess species reproducing sexually and asexually. Between them, Botryllus schlosseri forms similar organisms (oozooids and blastozooids) trough embryogenetic and blastogenetic pathways respectively. We here illustrate the characterization and expression pattern, during both pathways, of a transcript for a gene that we named BsMSI.We demonstrate that BsMSI falls into MuSashI-like (MSI-like) group, formed by MSI1, MSI2 and DAZAP1 genes. They encode for RNA-binding proteins phylogenetically related to other protein groups: the TARDBP and several hnRNPs. These proteins share same modular domain structure: a 2xRRM motif. Analyses show that MSIs-like and 2xRRM-hnRNPs had a common origin from a TARDBP type, and that 2xRRM-hnRNPs form a monophyletic group. A unique MSI-like, orthologous to DAZAP1, was recognized in tunicates. We hypothesize that, as MSIs are widely present in metazoans, tunicates have lost them during their evolution.In vertebrates MSI1 is considered a stem cells marker, but also MSI2 and DAZAP1 are involved in differentiative processes. BsMSI is expressed in all the tissues of developing buds. This ubiquitous blastogenetic expression differs from the embryogenesis one, which varies spatio-temporally according to the differentiation of embryonic, larval or oozooid tissues. Interestingly, BsMSI expression ends in differentiated or regressing structures (adult blastozooids, differentiated larval structures).Because the BsMSI expression patterndoesn’t overlap between blastogenesis and embryogenesis, we speculate it operates substitutive functions of the vertebrates orthologues DAZAP, MSI1 and MSI2, and that the function, related to differentiation or tissue maintaining, varies during the B. schlosseri life cycle
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
Expression of a Musashi-like gene in sexual and asexual development of the colonial chordate Botryllus schlosseri and phylogenetic analysis of the protein group
Full text linkTunicates are the unique chordates to possess species reproducing sexually and asexually. Among them, the colonial ascidian Botryllus schlosseri is a reference model for the study of similarities and differences in these two developmental pathways. We here illustrate the characterization and expression pattern during both pathways of a transcript for a gene orthologous to Dazap1. Dazap1 genes encode for RNA-binding proteins and fall into the Musashi-like (Msi-like) group. Our phylogenetic analysis shows that these are related to other RNA-binding proteins (Tardbp and several heterogeneous nuclear ribonucleoproteins types) that share the same modular domain structure of conserved tandem RNA Recognition Motifs (RRMs). We also classify the whole group as derived from a single ancient duplication of the RRM. Our results also show that Dazap1 is expressed with discrete spatiotemporal pattern during embryogenesis and blastogenesis of B. schlosseri. It is never expressed in wholly differentiated tissues, but it is located in all bud tissues and in different spatiotemporally defined territories of embryos and larva. These expression patterns could indicate different roles in the two processes, but an intriguing relationship appears if aspects of cell division dynamics are taken into account, suggesting that it is related to the proliferative phases in all tissues, and raising a similarity with known Dazap1 orthologs in other metazoans. © 2011 Wiley Periodicals, Inc
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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