1,721,143 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

    Optical coherence tomography in alzheimer’s disease

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    Alzheimer’s disease (AD) is a neurodegenerative disorder, which is likely to start as mild cognitive impairment (MCI) several years before its fullblown clinical manifestation. In the last two decades, optical coherence tomography (OCT) has been used to observe a signifi cant loss in peripapillary retinal nerve fiber layer (RNFL) and in macular thickness and volume in patients affected by a form of mild to severe dementia. These morphological abnormalities correlate to some extent with the severity of the disease as evaluated with neuropsychological tests. Furthermore, these structural measures correlate with electrophysiological parameters of pattern electroretinogram, refl ecting integrity of the innermost retinal layers, but not with those of the visual evoked potentials, refl ecting activity of the post-chiasmatic visual pathway. The latter evidence suggests that RNFL thickness reduction is related to neuronal degeneration in the ganglion cell layer and not to a retrograde degeneration from the post-chiasmatic visual pathway. These data suggest a possible role of OCT in monitoring the progression of AD and in assessing the effectiveness of purported AD treatments

    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

    Electrophysiological (BAEPs) changes in subacute sclerosing panencephalitis

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    Over a period of time, the authors have studied a case of subacute sclerosing panencephalitis (SSPE), by means of brainstem auditory evoked potentials (BAEPs). The observed abnormalities of the conduction time along the early auditory pathways appeared to be related to the clinical picture; in fact, during periods of transitory clinical improvement these abnormalities were less evident. In addition, the encountered electrophysiological alterations consisted of a marked pathologic increase in the III-V interpeak latencies. The authors suggest that the BAEPs findings in their case could have been influenced by either unfavourable endogenous conditions (edema, electrolyte changes, etc.) or CNS segmental lesions due to focal viral distribution
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