1,720,973 research outputs found

    Effects of the essential oil from citrus lemon in male and female rats exposed to a persistent painful stimulation

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    The ability of olfaction to modulate behavior in mammalian species has repeatedly been demonstrated. Here we tested the properties of the volatile components of lemon essential oil. Male and female rats were allowed to inhale the aroma while experiencing a persistent nociceptive input (50 microl formalin, 5%); in the same animals the c-Fos immunohistochemistry was used to test the degree of neuronal activation of areas belonging to the limbic system. In formalin-treated animals, lemon essential oil decreased licking the injected paw, in both sexes; flinching and flexing were decreased in males and increased in females in the interphase (5-20 min) of the formalin test. Essential oil increased the c-Fos expression in the arcuate n. of the hypothalamus. Essential oil and formalin increased c-Fos in the paraventricular n. of the hypothalamus and in the dentate gyrus of the hippocampus. In the paraventricular n. of the thalamus formalin induced higher c-Fos than control in both sexes; when formalin treatment was carried out in presence of essential oil, c-Fos further increased in males, but remained at control levels in females. The present results clearly indicate the ability of lemon essential oil to modulate the behavioral and neuronal responses related to nociception and pain

    Secondary Gas Injection Effect on Dual-Bell Nozzle Flow Transition

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    Dual bell nozzles represent a possible solution to improve the performance of large liquid rocket engines for launcher first stages. During the low-altitude mode, the flow is separated and the separation line is located near the inflection of the nozzle wall, in a region characterized by a negative value of the wall pressure gradient and where side loads may occur. At high altitude the flow attaches to the nozzle wall and the full area ratio is used. The flow behavior during the transition between the two operating modes is analyzed by time-accurate simulations carried out on an axi-symmetric geometry and considering two configurations: one with a wall film cooling and the other without film. Aim of this study is to analyze the eect of the secondary gas injection on the dynamics of the separation point and on the transition time. Results show that film injection may substantially change the characteristic transition time and evolution

    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
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