1,720,975 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

    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

    Pulmonary adenocarcinomas presenting as ground-glass opacities on multidetector CT: three-dimensional computer-assisted analysis of growth pattern and doubling time

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    We aimed to evaluate the growth pattern and doubling time (DT) of pulmonary adenocarcinomas exhibiting ground-glass opacities (GGOs) on multidetector computed tomography (CT). METHODS The growth pattern and DT of 22 pulmonary adenocarcinomas exhibiting GGOs were retrospectively analyzed using three-dimensional semiautomatic software. Analysis of each lesion was based on calculations of volume and mass changes and their respective DTs throughout CT follow- up. Three-dimensional segmentation was performed by a single radiologist on each CT scan. The same observer and another radiologist independently repeated the segmentation at the baseline and the last CT scan to determine the variability of the measurements. The relationships among DTs, histopathology, and initial CT features of the lesions were also analyzed. RESULTS Pulmonary adenocarcinomas presenting as GGOs exhibited different growth patterns: some lesions grew rapidly and some grew slowly, whereas others alternated between periods of growth, stability, or shrinkage. A significant increase in volume and mass that exceeded the coefficient of repeatability of interobserver variability was observed in 72.7% and 84.2% of GGOs, respectively. The volume-DTs and mass-DTs were heterogeneous throughout the follow-up CT scan (range, -4293 to 21928 and -3113 to 17020 days, respectively), and their intra- and interobserver variabilities were moderately high. The volume-DTs and mass-DTs were not correlated with the initial CT features of GGOs; however, they were significantly shorter in invasive adenocarcinomas (P = 0.002 and P = 0.001, respectively). CONCLUSION Pulmonary adenocarcinomas exhibiting GGOs show heterogeneous growth patterns with a trend toward a progressive increase in size. DTs may be useful for predicting tumor aggressiveness

    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
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