1,722,065 research outputs found
Hippocampal volume in adult burn patients with and without posttraumatic stress disorder
No full textObjective: Increasing evidence suggests that posttraumatic stress disorder (PTSD) is associated with small hippocampal size. The authors compared trauma-exposed subjects with PTSD and trauma-exposed subjects without PTSD to clarify whether small hippocampal size is related to PTSD or to mere trauma exposure. Method: Three-dimensional structural magnetic resonance imaging was used to assess hippocampal volumes in 30 men who had recently been exposed to a severe burn trauma and 15 matched healthy comparison subjects. Results: Relative to the comparison subjects, the trauma-exposed subjects with PTSD (N=15) as well as the trauma-exposed subjects without PTSD (N=15) had significantly smaller volumes of the right hippocampus (subjects with PTSD: -12%; subjects without PTSD: -13%). Larger total areas of burned body surface were significantly related to smaller left hippocampal volumes. Use of analgesic/sedative treatment with the N-methyl-D-aspartic acid (NMDA) antagonist ketamine was significantly related to larger right hippocampal volumes and to stronger PTSD symptoms. Conclusions: PTSD is not a necessary condition for small hippocampal size in trauma-exposed individuals. Rather, the results provide evidence that smaller hippocampal size in trauma-exposed individuals is a result of traumatic stress. The posttraumatic application of NMDA antagonists may protect against hippocampal damage induced by traumatic stressors but increases the patient's risk of developing PTSD symptoms
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
Effects of molecular weight on the isothermal crystallization of poly(1-butene)
No full textThe effect of molecular weight on the crystallization behavior of isotactic poly(1-butene) (iPB) under quiescent, isothermal conditions is investigated by rheological and optical microscopy techniques. Small amplitude oscillatory shear experiments are used to determine the critical gel behavior of the crystallizing melt. The resulting critical gel time is related to the crystallization kinetics during the early stages of the process. While molecular weight does substantially not affect the gel characteristic time, the rheological parameters of the crystalline critical gel are found to be strongly dependent upon molecular weight, thus suggesting that the viscoelastic behavior in the early stages of crystallization is dictated by the molecular properties of the amorphous phase. Optical microscopy observations provide quantitative information on the growth rate and the morphology of the crystallites. It is found that the molecular weight has no effect on the iPB growth rate. Conversely, molecular weight affects the morphological transition from spherulites to square-shaped (hedrites) crystallites. The coupled effects of temperature and molecular weight on the spherulite-to-hedrite transition are presented in the form of a phase diagram which quantitatively confirms recent observations made by Fu et al
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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