1,720,961 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Involvement of the neuronal K/Cl cotransporter KCC2 in the plasticity of glutamatergic synapses
No full textL'efficacité de la transmission synaptique GABAergique est influencée par la concentration intracellulaire en ions chlorure. Dans les neurones matures, l'extrusion de ces ions par le transporteur neuronal potassium chlore de type 2 (KCC2) permet l'influx d'ions chlorure lors de l'activation des récepteurs du GABA de type A. Néanmoins, KCC2 est aussi enrichi à proximité des synapses excitatrices portées par les épines dendritiques qui correspondent à des protrusions dendritiques enrichies en actine. Alors que l'effet d'une suppression de KCC2 sur l'homéostasie des ions chlorure et la transmission GABAergique est largement documenté, peu de choses sont connues sur l'impact qu'une telle suppression peut avoir sur la transmission glutamatergique. Lors de ma thèse, j'ai exploré le rôle de KCC2 dans la potentialisation à long terme (LTP) de la transmission glutamatergique à l'origine des phénomènes d'apprentissage et de mémorisation. Ce travail a révélé que la suppression de KCC2 compromet les modifications fonctionnelles et structurales sous-tendant la LTP. Cet effet est associé à une inhibition de la cofilin, protéine responsable de la dépolymérisation de l'actine, qui corrèle avec une augmentation de la quantité d'actine filamenteuse dans les épines dendritiques. En empêchant l'inhibition de la cofilin liée à l'absence de KCC2, il m'a alors été possible de restaurer la LTP suggérant que KCC2 pourrait influencer cette forme de plasticité en régulant la dynamique de polymérisation du cytosquelette d'actine. Mes résultats démontrent que la fonction de KCC2 va au-delà du contrôle de l'homéostasie des ions chlorure et influence les mécanismes de plasticité de la synapse excitatrice.The polarity and efficacy of GABAergic synaptic transmission are both influenced by the intra-neuronal chloride concentration. In mature neurons, chloride extrusion through the neuronal K/Cl cotransporter KCC2 allows an inhibitory influx of chloride upon activation of GABAA receptors. Nevertheless, KCC2 is enriched in the vicinity of excitatory synapses within the dendritic spines that are actin-rich protrusions emerging from dendritic shafts. While it has become clear that KCC2 suppression alters chloride homeostasis and GABA signaling, little is known on its impact on glutamatergic transmission. In the laboratory, we have previously demonstrated that KCC2 suppression in mature neurons leads to decreased glutamatergic transmission efficacy through an ion-transport independent function of KCC2. During my PhD, I have explored how KCC2 may also impact LTP of glutamatergic synapses. My work reveals that KCC2 suppression compromises both functional and structural LTP at these synapses. This effect is associated with inhibition of the actin-severing protein cofilin and enhanced mobilization of F-actin in dendritic spines. Since LTP can be rescued by preventing cofilin inhibition upon KCC2 suppression, I suggest KCC2 might influence LTP through altered actin cytoskeleton dynamics. My results demonstrate that KCC2 function extends beyond the mere control of neuronal chloride homoeostasis and suggest regulation of KCC2 membrane stability may act as a metaplastic switch to gate long term plasticity at excitatory synapses in cortical neurons
Rôle du transporteur neuronal Potassium/Chlore KCC2 dans la plasticité des synapses glutamatergiques
Full text linkThe polarity and efficacy of GABAergic synaptic transmission are both influenced by the intra-neuronal chloride concentration. In mature neurons, chloride extrusion through the neuronal K/Cl cotransporter KCC2 allows an inhibitory influx of chloride upon activation of GABAA receptors. Nevertheless, KCC2 is enriched in the vicinity of excitatory synapses within the dendritic spines that are actin-rich protrusions emerging from dendritic shafts. While it has become clear that KCC2 suppression alters chloride homeostasis and GABA signaling, little is known on its impact on glutamatergic transmission. In the laboratory, we have previously demonstrated that KCC2 suppression in mature neurons leads to decreased glutamatergic transmission efficacy through an ion-transport independent function of KCC2. During my PhD, I have explored how KCC2 may also impact LTP of glutamatergic synapses. My work reveals that KCC2 suppression compromises both functional and structural LTP at these synapses. This effect is associated with inhibition of the actin-severing protein cofilin and enhanced mobilization of F-actin in dendritic spines. Since LTP can be rescued by preventing cofilin inhibition upon KCC2 suppression, I suggest KCC2 might influence LTP through altered actin cytoskeleton dynamics. My results demonstrate that KCC2 function extends beyond the mere control of neuronal chloride homoeostasis and suggest regulation of KCC2 membrane stability may act as a metaplastic switch to gate long term plasticity at excitatory synapses in cortical neurons.L'efficacité de la transmission synaptique GABAergique est influencée par la concentration intracellulaire en ions chlorure. Dans les neurones matures, l'extrusion de ces ions par le transporteur neuronal potassium chlore de type 2 (KCC2) permet l'influx d'ions chlorure lors de l'activation des récepteurs du GABA de type A. Néanmoins, KCC2 est aussi enrichi à proximité des synapses excitatrices portées par les épines dendritiques qui correspondent à des protrusions dendritiques enrichies en actine. Alors que l'effet d'une suppression de KCC2 sur l'homéostasie des ions chlorure et la transmission GABAergique est largement documenté, peu de choses sont connues sur l'impact qu'une telle suppression peut avoir sur la transmission glutamatergique. Lors de ma thèse, j'ai exploré le rôle de KCC2 dans la potentialisation à long terme (LTP) de la transmission glutamatergique à l'origine des phénomènes d'apprentissage et de mémorisation. Ce travail a révélé que la suppression de KCC2 compromet les modifications fonctionnelles et structurales sous-tendant la LTP. Cet effet est associé à une inhibition de la cofilin, protéine responsable de la dépolymérisation de l'actine, qui corrèle avec une augmentation de la quantité d'actine filamenteuse dans les épines dendritiques. En empêchant l'inhibition de la cofilin liée à l'absence de KCC2, il m'a alors été possible de restaurer la LTP suggérant que KCC2 pourrait influencer cette forme de plasticité en régulant la dynamique de polymérisation du cytosquelette d'actine. Mes résultats démontrent que la fonction de KCC2 va au-delà du contrôle de l'homéostasie des ions chlorure et influence les mécanismes de plasticité de la synapse excitatrice
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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