1,720,971 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Postnatal development and sensory experience synergistically underlie the excitatory/inhibitory features of hippocampal neural circuits: Glutamatergic and GABAergic neurotransmission
No full textDuring a postnatal critical period balance of excitation/inhibition in the developing brain is highly regulated by environmental signals. Compared to the visual cortex, rare document includes effects of sensory experience on the hippocampus, which is also bombarded by sensory signals. In this study, basic and tetanized field excitatory postsynaptic potentials (fEPSPs) were recorded in CA1 area of hippocampus of light-(LR) and dark-reared (DR) rats (at 2, 4 and 6 weeks of age). Also, we assessed age- and activity-dependent changes in the N-Methyl- d-aspartic acid (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors subunit compositions and, GABA producing enzymes. While the sensory deprivation increased amplitude of baseline fEPSPs, it decreased degree of potentiation of post-tetanus responses. Expression of GluA1 and GluA2 subunits of AMPA receptors was increased across age in DR rats. In contrast to LR rats, mRNA and protein expression of GluN1, GluN2A and GluN2B subunits of NMDA receptors was decreased in DR ones. Also, dark rearing diminished expression of GABA synthesis enzymes GAD65 and GAD67. These results indicate that, sensory experience adjusts synaptic plasticity and might also affect the balance of excitation/inhibition in the hippocampus. © 2016 IBRO
Visual deprivation during critical period of brain development inhibits expression of glutamic acid decarboxylase enzyme in rat hippocampus
No full textIntroduction: Visual deprivation during critical period of brain development inhibits the GABAergic system growth and completion in visual cortex. Because parts of visual signals are transferred to hippocampus through the visual cortex, the aim of this experiment was to study the effects of visual deprivation during critical period of brain development on expression of Glutamic Acid Decarboxylase enzyme in rats� hippocampus. Materials and methods: This study was carried on 2 groups (n=36) of male rats kept in standard 12 hour light/dark cycle (Light reared, LR) or in complete darkness (Dark reared, DR). Each group, in turn, was divided into 3 aged-based subgroups of 2, 4 and 6 weeks old rats. Using RT-PCR and Western Blot techniques, expression of both isoforms of Glutamic Acid Decarboxylase enzyme were investigated in hippocampus. Results: Relative expression of mRNA and protein of GAD65 and GAD67 enzymes increased in the LR animals, time dependently. However, although the expression of both enzymes increased in the DR animals by aging, but, the expression was much lower in compare to the LR rats. Conclusion: Visual deprivation during critical period of brain development inhibits the expression of GAD65 and GAD67 enzymes in rat hippocampus and delays GABAergic system development. © 2015, Semnan University of Medical Sciences. All rights reserved
Evaluating effects of visual deprivation during critical period of brain development on expression of NMDA receptor subunits in rats hippocampus
No full textBackground and purpose: Visual deprivation during critical period of brain development impairs structure and function of NMDA receptors in visual cortex. Parts of visual signals go to the hippocampus through the visual cortex. Therefore, this study aimed at investigating the effects of visual deprivation during critical period of brain development on NMDA receptor subunits expression in rats hippocampus. Materials and methods: This experimental study was carried out in 36 male rats that were divided into two groups. They were kept in standard 12 hour light/dark condition (Light Reared-LR) or in complete darkness (Dark Reared-DR) from birth to the time of experiments. The animals in each group were divided into 3 groups and studied at the ages of 2, 4 and 6 weeks. Expression of mRNA of NR1, NR2A and NR2B subunits in hippocampus was evaluated by RT-PCR using Western Blot technique. The protein expression of those subunits was also investigated.Results: Relative expression of mRNA and protein of NR1 and NR2A subunits increased time dependently in LR animals, but the expression of NR2B subunit did not change. Although dark rearing did not prevent increasing of NR1 expression, but reduced the expression of NR2A and NR2B subunits.Conclusion: Visual deprivation during critical period of brain development time dependently inhibited maturation of NMDA receptor of rat�s hippocampus. © 2015, J Mazandaran Univ Med Sci. All rights reserved
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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