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    NON INVASIVE MODERATE LOADING IN VIVO AND OSTEOARTHRITIS DEVELOPMENT

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    Mechanical loading is known to modify joint structure through a mechano-adaptative response and to increase proinflammatory cytokines, as IL-1β, modulating VEGF secretion by condrocytes1. VEGF is a potent angiogenic factor, also detectable in later stages of OA, able to increase matrix MMPs playing an important role in the development of OA2. The aim of this study is to evaluate “in vivo” changes of bone and cartilage leading to OA by means of nonsurgical intermittent moderate loading. Forty day-old mice was randomly divided into two groups of six animals each: sedentary and exercised. The exercised group was subjected to a treadmill running at 12m/min, two times a week for four weeks. The sedentary group did not undergo any physical training and was left free to walk inside the cages. After the sacrifice the femur heads were removed and processed for paraffin embedding. On 5μm coronal sections, safranine-O staining and immunostaining for IL-1 β, MMP-13 and VEGF was performed to evaluate: articular cartilage and subchondral bone trabeculae thickness; chondrocytes number/mm2; chondrocytes volume; % cell number expressing VEGF, IL-1β and MMP-13 in articular cartilage and bone. Significant increase of chondrocytes volume, VEGF and MMP-13 expression in cartilage was detected. These data seem indicate that our non-invasive experimental model could induce early alterations in articular cartilage only, confirming chondrocytes to play a central role in the pathogenesis of OA. Other alterations, such as articular cartilage cracking and thickening and sub-chondral bone sclerosis, would appear later

    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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