1,720,961 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

    Modal gating of human Ca(v)2.1 (P/Q-type) calcium channels: I. The slow and the fast gating modes and their modulation by beta subunits

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    The single channel gating properties of human Ca(V)2.1 (P/Q-type) calcium channels and their modulation by the auxiliary beta(1b), beta(2c), beta(3a), and beta(4a), subunits were investigated with cell-attached patch-clamp recordings on HEK293 cells stably expressing human Ca(V)2.1 channels. These calcium channels showed a complex modal grating. which is described in this and the following paper (Fellin, T., S. Luvisetto, M. Spagnolo, and D. Pietrobon. 2004. J Gen. Physiol. 124:463-474). Here, we report the characterization of two modes of gating of human Ca(V)2.1 channels, the slow mode and the fast mode. A channel in the two gating modes differs in mean closed times and latency to first opening (both longer in the slow mode), in voltage dependence of the open probability (larger depolarizations are necessary to open the channel in the slow mode), in kinetics of inactivation (slowed in the slow mode), and voltage dependence of steady-state inactivation (occurring at less negative voltages in the slow mode). Ca(V)2.1 channels containing any of the four beta subtypes can gate in either the slow or the fast mode, with only minor differences in the rate constants of the transitions between closed and open states within each mode. In both modes; Ca(V)2.1 channels display different rates of inactivation and different steady-state inactivation depending oil the P subtype. The type of beta subunit also modulates the relative occurrence of the slow and the fast gating mode of Ca(V)2.1 channels, beta(3a), promotes the fast mode, whereas beta(4a) Promotes the slow mode. The prevailing mode of gating, of Ca(V)2.1 channels lacking a beta subunit is a gating mode in which the channel shows shorter mean open times, longer mean closed times, longer first latency, a much larger fraction of mills, and activates at more positive voltages than in either the fast or slow mode

    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

    Human neuronal stargazin-like proteins, gamma(2), gamma(3) and gamma(4); an investigation of their specific localization in human brain and their influence on Ca(V)2.1 voltage-dependent calcium channels expressed in Xenopus oocytes

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    Background: Stargazin (gamma(2)) and the closely related gamma(3), and gamma(4) transmembrane proteins are part of a family of proteins that may act as both neuronal voltage-dependent calcium channel (VDCC) gamma subunits and transmembrane alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproponinc (AMPA) receptor regulatory proteins (TARPs). In this investigation, we examined the distribution patterns of the stargazin-like proteins gamma(2), gamma(3), and gamma(4) in the human central nervous system (CNS). In addition, we investigated whether human gamma(2) or gamma(4) could modulate the electrophysiological properties of a neuronal VDCC complex transiently expressed in Xenopus oocytes.Results: The mRNA encoding human gamma(2) is highly expressed in cerebellum, cerebral cortex, hippocampus and thalamus, whereas gamma(3) is abundant in cerebral cortex and amygdala and gamma(4) in the basal ganglia. Immunohistochemical analysis of the cerebellum determined that both gamma(2) and gamma(4) are present in the molecular layer, particularly in Purkinje cell bodies and dendrites, but have an inverse expression pattern to one another in the dentate cerebellar nucleus. They are also detected in the interneurons of the granule cell layer though only gamma(2) is clearly detected in granule cells. The hippocampus stains for gamma(2) and gamma(4) throughout the layers of the every CA region and the dentate gyrus, whilst gamma(3) appears to be localized particularly to the pyramidal and granule cell bodies. When co-expressed in Xenopus oocytes with a Ca(V)2.1/beta(4) VDCC complex, either in the absence or presence of an alpha(2)delta(2) subunit, neither gamma(2) nor gamma(4) significantly modulated the VDCC peak current amplitude, voltage-dependence of activation or voltage-dependence of steady-state inactivation.Conclusion: The human gamma(2), gamma(3) and gamma(4) stargazin-like proteins are detected only in the CNS and display differential distributions among brain regions and several cell types in found in the cerebellum and hippocampus. These distribution patterns closely resemble those reported by other laboratories for the rodent orthologues of each protein. Whilst the fact that neither gamma(2) nor gamma(4) modulated the properties of a VDCC complex with which they could associate in vivo in Purkinje cells adds weight to the hypothesis that the principal role of these proteins is not as auxiliary subunits of VDCCs, it does not exclude the possibility that they play another role in VDCC function

    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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