1,721,059 research outputs found

    Contribution of NMDA and non-NMDA glutamate receptors to locomotor pattern generation in the neonatal rat spinal cord

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    The motor programme executed by the spinal cord to generate locomotion involves glutamate-mediated excitatory synaptic transmission. Using the neonatal rat spinal cord as an in vitro model in which the locomotor pattern was evoked by 5-hydroxytryptamine (5-HT), we investigated the role of N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors in the generation of locomotor patterns recorded electrophysiologically from pairs of ventral roots. In a control solution, 5-HT (2.5-30 μM) elicited persistent alternating activity in left and right lumbar ventral roots. Increasing 5-HT concentration within this range resulted in increased cycle frequency (on average from 8 to 20 cycles min-l). In the presence of NMDA receptor antagonism, persistent alternating activity was still observed as long as 5-HT doses were increased (range 20-40 μM), even if locomotor pattern frequency was lower than in the control solution. In the presence of non-NMDA receptor antagonism, stable locomotor activity (with lower cycle frequency) was also elicited by 5-HT, albeit with doses larger than in the control solution (15-40 μM). When NMDA and non-NMDA receptors were simultaneously blocked, 5-HT (5-120 μM) always failed to elicit locomotor activity. These data show that the operation of one glutamate receptor class was sufficient to express locomotor activity. As locomotor activity developed at a lower frequency than in the control solution after pharmacological block of either NMDA or non-NMDA receptors, it is suggested that both receptor classes were involved in locomotor pattern generation

    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

    Effects of recreational football performed once a week (1 hour per 12 weeks) on cardiovascular risk factors in middle-aged sedentary men

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    Objectives: It is well established that there is a strong relationship between physical activity, cardiovascular diseases and mortality. Regular recreational football training can lower blood pressure, heart rate at rest, fat percentage, LDL cholesterol and increase maximal aerobic power (VO2max). This study analyzed the effect of one recreational football training per week on middle-aged men. Design: Randomized controlled trial. Methods: Twenty-four participants (mean ± SDs; age 44.5 ± 4.7 years, weight 81.9 ± 10.4 kg, height 175.0 ± 7.3 cm) were randomized in a football group (FG = 10) and control group (CG = 14). FG performed supervised recreational football training (five-a-side futsal match) on 36 × 18.5 m synthetic indoor and outdoor field, 60 min per week over 12 weeks. Results: After training, VO2max and maximal aerobic speed improved in FG respectively of 4.4% (+1.89 mL O2⋅ kg−1.min−1 , P = 0.002) and 5.9% (P = 0.01). Systolic and mean blood pressure decreased respectively of 2.5% (−3.18 mmHg, P = 0.04) and 2.2% (−2.28 mmHg, P = 0.04) in FG, while diastolic blood pressure did not change (−1.84 mmHg, P = 0.09). Conclusions: Recreational football activity produces health benefits by improving VO2 max and lowering blood pressure parameters in middle-aged men

    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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