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    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

    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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    Volume CLEM and conventional EM: a dual approach to investigate the mechanism of neuronal dysfunction in Angelman Syndrome

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    Angelman Syndrome (AS) is a rare neurodevelopmental disorder arising from the loss of the maternal copy of UBE3A, a paternally imprinted gene at neuronal level. Similarly to AS, other neurological defects due to an unproper UBE3A dosage are directly associated with alterations in brain development and synapse ultrastructure. The nanometric resolution of electron microscopy (EM) has proven essential for studying their outcome at the network level and establishing meaningful correlations between synapses geometrical features and their function. To explore whether UBE3A loss effect on the developing connectome was cell-autonomous, we in-utero electroporated CRISPR/Cas9 constructs to silence the endogenous UBE3A expression in a subset of layer 2/3 pyramidal neurons of the mouse somatosensory cortex. By creating z-confined NIRB marks we were able to relocate dendrites of interest and analyze spines complexity three-dimensionally from volumetric SBF-SEM datasets. Furthermore, we exploited conventional EM to examine excitatory synapses structure in the cortical circuit of a classic AS model pan-neuronally depleted from UBE3A expression. We identified pre-synaptic compartment defects that seem to diminish over time to make room for later changes in the post-synapse. Overall, the combined use of these two models should help clarify whether the defects originate within the neurons or their wider network
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