1,721,023 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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 link
    We 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 link
    We 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

    Author Index

    No full text
    Nao informado

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We 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

    Alkaline Sphingomyelinase; A Potential Inhibitor in Colorectal Carcinogenesis

    No full text
    Sphingomyelin (SM) is present both in eucaryotic cells and the diet. Sphingomyelinase (SMase) hydrolyses SM and generates ceramide that has been implicated in the regulation of cell growth, differentiation and apoptosis. Previously a SMase with alkaline pH optimum was identified in the intestinal tract. The thesis studied the distribution pattern, the species difference and the clinical implications of this enzyme. Unlike neutral and acid SMase, which are present in most tissues, alkaline SMase is specifically located to the intestinal tract. The distribution pattern in human intestine was similar to other species such as rats, mice and hamsters, the highest values were demonstrated in the jejunum and lower in the colon. Man was the only species examined with an additional alkaline SMase in the bile. After giving SM orally to ileostomists, both SM and ceramide were accumulated in the stoma output indicating that the colonic mucosa is exposed to ceramide. When the activities of three SMases were determined in patients with human colorectal carcinoma (CRC), all SMases were reduced in cancer tissue compared to the surrounding mucosa, but the most predominant reduction being for alkaline SMase by (75%, p=0.004). Furthermore, the enzyme activity was markedly decreased by 90% (p<0.001) in adenoma tissue and in flat mucosa of patients with familial adenomatous polyposis compared to controls. These results suggested a potential link to APC mutations. However, when the activities of the enzyme were studied in the Min mouse (germline APC mutations) and human CRC tissue (Somatic APC mutations), no direct link was identified. Finally, we studied the effect of a purified rat intestinal alkaline SMase on growth in human HT-29 colon carcinoma cells and non-transformed rat intestinal IEC-6 cells. Alkaline SMase inhibited cell proliferation of HT-29 cells but not IEC-6 cells. In contrast, a bacterial neutral SMase had no effect. Alkaline SMase did not induce apoptosis. The antiproliferative effect was accompanied by SM hydrolysis and ceramide production. Alkaline SMase did not induce apoptosis whereas C2-ceramide and sulindac did. In conclusion, alkaline SMase is a gut specific enzyme with antiproliferative properties. The enzyme may be important in cell growth regulation and its reduction may facilitate the development of colorectal cancer
    corecore