1,720,967 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
Immunocytological determination of lymphocytes and monocytes/macrophages in urinary sediments of renal allograft recipients
No full textBackground. Urinary studies using Papanicolaou staining following kidney transplantation led to the conjecture that acute allograft rejection might be accompanied by an increased lymphocyturia. However, it is difficult to distinguish lymphoid cells from other urinary cells using conventional stains. Methods. Staining of urinary lymphocytes using FITC-labelled antibodies is complicated by a high unspecific fluorescence that limits the evaluation. Therefore, we developed a method to stain urinary lymphocytes using enzyme-linked antibodies. The cells were cytocentrifuged onto microscope slides and were fixed. Results. By means of a combined evaluation of Papanicolaou and immunocytochemical staining, CD3-positive pan T cells, CD4-positive T-helper cells, CD8-positive cytotoxic/suppressor cells, and CD14-positive monocytes/macrophages of urinary sediments were determined in 41 kidney graft recipients following renal transplantation. During periods of normal graft function, neither positive lymphocytes nor positive monocytes/macrophages were found in the urinary sediments. However, in the course of acute allograft rejection a significant increase in positive lymphocytes and positive monocytes/macrophages could be observed. Interestingly, in cases of acute allograft rejection the distribution of urinary lymphocytes and monocytes was comparable to the distribution of infiltrating immunocompetent cells in renal allograft biopsies. Conclusion. The present study demonstrates that immunocytochemical staining via enzyme-conjugated antibodies is a reliable method to visualize T lymphocytes and monocytes/macrophages in the urinary sediment, and that this technique may be of special diagnostic value in the diagnosis of acute allograft rejection
Evidence for a sorbitol transport system in immortalized human renal interstitial cells
No full textSorbitol plays a major role in the maintenance of cell volume and functional integrity of several renal cells. Sorbitol synthesis takes place in inner collecting duct cells, whereas sorbitol dehydrogenase activity, which catalyzes the degradation of sorbiotol to fructose, could mainly be detected in renal inner medullary interstitial cells. Therefore, we supposed that interstitial cells would require a sorbitol transport into the cells. However, such a transport system has not yet been described. Therefore, we have characterized the uptake of sorbitol in immortalized interstitial TK-173 cells, which were derived from human renal fibroblasts. Comparable to fresh isolated renal fibroblasts of the rat, immortalized TK-173 cells have a high sorbitol dehydrogenase activity. In this report, a temperature-dependent sorbitol uptake with saturation kinetics could be detected in immortalized TK-173 cells. The transport is characterized by a high velocity (V-max 84 mmol/l x h) and an apparent K-m of 10 mmol/l. The sorbitol uptake is independent of membrane potential, sodium, and chloride. Altogether, the physiological characteristics of this sorbitol transport are different from those of the osmotically regulated sorbitol efflux from epithelial cells. These results provide evidence that TK-173 cells derived from renal fibroblasts have a specific sorbitol transport. Furthermore, these data suggest a cooperation between epithelial and interstitial cells concerning osmoregulation. Copyright (C) 2001 S. Karger AG, Basel
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
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