1,720,955 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
An investigation of cellular and molecular mechanisms of stem cell regulation in Schmidtea mediterranea
Full text linkThe planarian Schmidtea mediterranea discovered by Benazzi, Baguñà, Ballester, Puccinelli & Del Papa, 1975 is a classic model organism for the investigation of regenerative processes. The source of new tissues is a population of proliferative cells called 'neoblasts'. The level of heterogeneity among this population of cells is unknown. However at least a proportion of neoblasts are pluripotent stem cells, and these are sometimes referred to as clonogenic neoblasts (cNeoblasts). Although the Schmidtea mediterranea genome has been sequenced, and RNAi techniques are well established, our knowledge of the molecular regulators of neoblast behaviours such as migration in-vivo remain limited. This thesis presents an assay for tracking spatio-temporal processes such as stem cell migration and division. Data presented herein supports the assays potential as an adjunct method for functional testing of molecular regulators of stem cell biology. Moreover this thesis demonstrates the effect of various gene knockdowns on cell migration in vivo. The matrix metalloprotease MTMMPA has been shown herein to inhibit stem cell and progeny migration. Conversely the serine threonine kinase and tumor suppressor SMG-1 has been shown to positively effect cell migration and regeneration time frames. This 'over activity' in SMG RNAi has also been demonstrated to ultimately result in the formation of ectopic growths, analogous with tumor masses seen in cancer. The characterisation of the Methyl-CpG-binding domain protein MBD 2/3 has been expanded upon to include a migration effect. MBD 2/3 RNAi animals exposed to shielded irradiation fail to regenerate as previously published by Jaber 20141 and through the use of Fluorescent Insitu Hybridisation (FISH) visualisation we can confirm that this phenotype is in part attributable to cell migration failure. This body of work also demonstrates the ability of the developed assay to uncover otherwise undetectable phenotypes. Knockdown of the well-known cancer implicated zinc finger protein SNAIL has previously failed to give rise to regeneration defects in planarians. However in the shielded irradiation paradigm SNAIL RNAi does result in a lethal regenerate defect. SNAIL RNAi animals are able to maintain their stem cell and progeny populations, suggesting SNAIL does not have a role in cell maintenance and differentiation. However, investigations using a Fluorescent In situ Hybridisation technique (FISH) show that the cells of SNAIL RNAi animals fail to migrate, supporting the broadly proposed role for SNAIL in the promotion of cell migration. Four additional genes selected using the Oncomine web-based microarray database have been identified as having a role in planarian biological processes. Knockdown of gene UDP-Nacteylglucosamine pyrophosphorylase 1 (UAP1) caused homeostatic animals to regress their heads. Further investigations using FISH to visualise underlying cell behaviours is required, however head regression is associated with stem cell defect in the planarian model2. Knockdown of ribosomal biogenesis protein (WDR12), thyroid hormone receptor interactor 13 (TRIP13) and Bystin (BYSL) resulted in regeneration defects. To the best of our knowledge these genes have never before been investigated in planarians. The phenotypes, all characterised by a failure of animals to regrow a head, were only observable in shielded irradiation experiments. Detailed characterisation of the underlying cellular and molecular mechanisms of these defects is required. However the observations presented herein are adequate to propose that the assay developed has significant potential as a novel technique for the planarian community to investigate important cell behaviours, particularly cell migration, which has a key role in disease, specifically cancer metastasis
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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