1,721,004 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    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

    Methods for diagnosing bile acid malabsorption: a systematic review

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    Background: Bile acid malabsorption (BAM) and bile acid-related diarrhea represent an under-recognized cause of chronic diarrhea mainly because of limited guidance on appropriate diagnostic and laboratory tests. We aimed to perform a systematic review of the literature in order to identify and compare the diagnostic accuracy of different diagnostic methods for patients with BAM, despite a proven gold standard test is still lacking. Methods: A PubMed literature review and a manual search were carried out. Relevant full papers, evaluating the diagnostic accuracy of different methods for BAM, were assessed. Available data were analyzed to estimate the sensitivity and specificity of each published test. Results: Overall, more than one test was considered in published papers on BAM. The search strategy retrieved 574 articles; of these, only 16 were full papers (with a total of 2.332 patients) included in the final review. Specifically, n = 8 studies used 75Selenium-homotaurocholic-acid-test (75SeHCAT) with a < 10% retention threshold; n = 8 studies evaluated fasting serum 7-α-hydroxy-4-cholesten-3-one (C4); n = 3 studies involved total fecal bile acid (BA) excretion over 48 h; n = 4 studies assessed fibroblast growth factor 19 (FGF19). 75SeHCAT showed an average sensitivity and specificity of 87.32 and 93.2%, respectively, followed by serum C4 (85.2 and 71.1%) and total fecal BA (66.6 and 79.3%). Fasting serum FGF19 had the lowest sensitivity and specificity (63.8 and 72.3%). All the extracted data were associated with substantial heterogeneity. Conclusions: Our systematic review indicates that 75SeHCAT has the highest diagnostic accuracy for BAM, followed by serum C4 assay. The diagnostic yield of fecal BA and FGF19 assays is still under investigation. Our review reinforces the need for novel biomarkers aimed to an objective detection of BAM and therefore improving the management of this condition

    Variations on the Author

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    “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

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    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

    Monte Carlo simulations and dose measurements of 2D range-modulators for scanned particle therapy

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    This paper introduces the concept of a 2D range-modulator as a static device for generating spread-out Bragg peaks at very small distances to the target. The 2D range-modulator has some distinct advantages that can be highly useful for different research projects in particle therapy facilities. Most importantly, it creates an instantaneous, quasi-static irradiation field with only one energy, thus decreasing irradiation time tremendously. In addition, it can be manufactured fast and cost efficiently and its SOBP width and shape can be adjusted easily for the specific purpose/experiment. As the modulator is a static element, there is no need for rotation (e.g. like in a modulation wheel) or lateral oscillation and due to the small base structure period it can be positioned close to the target. Two different rapid prototyping manufacturing techniques were utilized. The modulation properties of one polymer and one steel modulator were investigated with both simulations and measurements. For this purpose, a sophisticated water phantom system (WERNER), that can perform fast, completely automated and high resolution dose measurements, was developed. Using WERNER, the dose distribution of a modulator can be verified quickly and reliably, both during experiments, as well as in a time constrained clinical environment. The maximum deviation between the Monte Carlo simulations and dose measurements in the spread-out Bragg peak region was 1.4% and 4% for the polymer and steel modulator respectively. They were able to create spread-out Bragg peaks with a high degree of dose homogeneity, thus validating the whole process chain, from the mathematical optimization and modulator development, to manufacturing, MC simulations and dose measurements. Combining the convenience, flexibility and cost-effectiveness of rapid prototyping with the advantages of highly customizable modulators, that can be adapted for different experiments, the 2D range-modulator is considered a very useful tool for a variety of research objectives. Moreover, we have successfully shown that the manufacturing of 2D modulators with high quality and high degree of homogeneity is possible, paving the way for the further development of the more complex 3D range-modulators, which are considered a viable option for the very fast treatment of moving targets and/or FLASH irradiation

    Dispelling the Myths Behind First-author Citation Counts

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    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

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    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
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