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
Analisi funzionale di un gene di Saccharomyces cerevisiae che codifica una proteinchinasi a struttura particolare
No full text
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
Letter: oesophageal histological abnormalities and GERD - an underestimated relationship requiring more attention
No full textDear Sirs,
we read with great interest the manuscript by Vakil et al (1) regarding a post-hoc analysis of the Diamond study, a single-blind, single-arm investigation evaluating the accuracy of the diagnosis of gastro-oesophageal reflux disease (GORD) by the Reflux Disease Questionnaire (RDQ), family practitioners, gastroenterologists and a test of esomeprazole therapy. The Authors analyzed distal oesophageal biopsies from 127 (55%) of the 231 included patients who were diagnosed with GERD based on endoscopic and functional investigations and found that adding epithelial hyperplasia (>430 μm) at histological assessment, as a diagnostic criterion, increased the number of patients diagnosed with GERD on investigation by 28 [12%; number needed to diagnose (NND): 8] to 155 (67%).
We appreciated the efforts made by the Authors in order to confirm the role of histology in defining a GERD diagnosis in case of negative endoscopy, normal acid exposure time and negative symptom-reflux association. To note, the value of histology in this particular setting (i.e. endoscopy negative patients with negative or borderline reflux testing) has been recently emphasized by an international consensus of experts (2). Indeed, relevant recent studies underlined the potential increasing diagnostic yield of diagnosing GERD by adding esophageal histological assessment (3,4). In particular, using current state of the art method for reflux monitoring, that is impedance-pH, we observed that a diagnosis of microscopic esophagitis, based on the presence of dilatation of intercellular spaces, papillary elongation, basal cell hyperplasia and inflammatory cells, was able to differentiate patients with non-erosive reflux disease from those with functional heartburn and healthy volunteers with an accuracy of 79%, a sensitivity of 74%, and a specificity of 86%, similar to what has been demonstrated by Kandulski et al (3,4). On the other hand, Vakil et al. showed that epithelial thickness >430 μm on esophageal biopsies performed 2 cm above the Z line had a specificity of only 76% and a sensitivity of 48%. For this reason, we strongly argue that whether we want to consider histology as additional tool for GERD diagnosis, the inclusion of the whole histological lesions associated to GERD should be considered and evaluated, in order to maximize the value of the information we can obtain from the esophageal mucosal status. Furthermore, we would like also to say that, in contrast to what has been reported by Roman et al. (5), histological assessment has low cost and, in general, is increasing suggested by different guidelines underling the need of biopsies due to the raising incidence of eosinophilic esophagitis in the general population.
In conclusion, given the increased diagnostic yield of histology in case of GERD suspicion, we believe that histological evaluation should be performed when clinical suspicion is high and endoscopy or reflux monitoring are negative or provided inconclusive results
Analisi funzionale di un gene di Saccharomyces cerevisiae che codifica una protein chinasi a struttura particolare
No full textFunctional analysis of the YGR262c/Vsk1 gene encoding an atypical protein kinase essential for normal cell growth
No full textThe S.cerevisiae YGR262c gene, whose deletion confers to yeast cells a pleiotropic phenotype characterized, among other defects, by severe slow-growth, inability of homozygous diploids to enter sporulation and important alterations in cell wall structure, encodes a 261 residues protein kinase, piD261, now renamed Vsk1p (very small kinase 1), whose structurl homologues are present in a variety of organisms and whose function is unknown. We have previously demonstrated that the protein is a S/T kinase and here we show, by mutational analysis, that the invariant residues of protein kinase are all conserved in Vsk1p, but are embedded in a altered context, suggestive of unique mechanistic properties. The biological competence of the Vsk1p protein is correlated with its phosphotransferase activity, as the phenotype due to the VSK1 gene disruption is not, or partially, complemented by ectopic expression of Vsk1p point mutants which are catalitically inactive in vitro. However, the absence of the protein causes in the cell more dramatic effects thn its presence in a catalitically inactive form and this is possibly due to the failure to form protein complex(es) within the cell. In order to understand the actual role of the protein, we have started a search for protein(s) functionally associated with Vsk1p by the 2-hybrid approach. Two of the interacting proteins could be good candidates to correlate the function of this protein with the manifested phenotypes
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
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