1,721,011 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
Role of signalling molecules in the developing avian wing
Full text linkThe aim of this study was to investigate the role of signalling molecules during the development of the chick limb. First, it was demonstrated that a functional gradient of bioactive FGFs is present down the limb from distal to proximal. This functional FGF gradient decreased at stage 26, at the time of AER regression. Although morphogenetic gradients are of considerable theoretical importance in developmental biology, there are rather few practical demonstrations of their existence. The effects of prolonging the presence of active FGF on limb pattern formation were investigated. Application of ectopic FGF-4 to the distal tip of the limb at stage 26 had a number of effects on limb development. In particular, the cartilage structure conventionally labelled element "5" increased in size and in some instances acquired a digit-like morphology. The evolutionary considerations of this finding are briefly considered. Analysis, including 3D computer reconstruction, of the musculature and vasculature of limbs after FGF implants was carried out in the hope of establishing the identity of this digit like element. This proved not to be possible. However, both muscle mass and vascularisation had increased after the procedure. Known molecular pathways involving the proximo-distal patterning of the limb were then investigated. Whole mount in situ hybridisation studies were carried out with respect to FGF-4, sonic hedgehog, Hoxd-11 and FGF-8. These revealed that the shh/ FGF positive feedback loop was not involved in these changes. FGF-8 expression in late stage AERs was markedly increased. Hoxd-11 expression was not affected by ectopic FGF implants. Together, these findings suggest that the effect of FGF implants is mediated by a novel mechanism. The effect of FGF-4 implants on programmed cell death in the limb was examined. At stage 28 anterior necrotic zone was larger, and had shifted distally. However, the posterior necrotic zone was absent. The implications of these findings for limb development were discussed
Influence of BLyS on Peripheral B Lymphocyte Tolerance
No full textHow self-reactive B cells are regulated during naïve and antigen-driven B cell development remains poorly understood. The peripheral B cell pro-survival cytokine B lymphocyte stimulator (BLyS) has been proposed to participate in the regulation of immunological tolerance. This thesis focused on the role BLyS plays in the selection processes governing formation of the naïve B cell repertoire, and during antigen-driven B cell differentiation. To address these questions I employed targeted immunoglobulin heavy chain transgenic mouse lines designated as heavy chain knock-in (HKI). HKI mice produce large numbers of naïve follicular B cells that are either weakly (HKI65) or strongly (HKIR) self-reactive with nuclear autoantigens. Past work in related but distinct systems suggested that BLyS availability plays a central role in the selection of self-reactive cells. By contrast, I found that counter-selection of nuclear antigen-reactive HKI B cells was not influenced by changes in BLyS availability. Mature, naive, autoreactive HKIR and HKI65 B cells were equally outcompeted for representation in the periphery by a polyclonal B cell population. However, the failure of HKIR and HKI65 B cells to thrive was not due to a higher dependency of HKI B cells on BLyS for survival. As such, my data indicate the existence of peripheral tolerance mechanisms that regulate the frequency of autoreactive follicular B cells independent of the BLyS pathway. For the second part of my thesis, I tested the role of BLyS in the selection of autoreactive HKI B cells during antigen-driven B cell differentiation as these cells enter germinal centers (GCs). Experiments were performed to determine whether BLyS expression or presentation by follicular helper T cells (TFH) influences the counter-selection of self-reactive HKI B cells in the GCs. The resulting data indicate that GCs were established and maintained in the absence of BLyS production in TFHs. However, the effect of BLyS on germinal center negative selection was difficult to interpret, owing in part to modest differences observed between the participation of HKIR and HKI65 clones in the GCs. One potential conclusion is that local BLyS activity is dispensable for germinal center B cell survival
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
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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