1,720,979 research outputs found
Cardiovascular Adaptations in Spinal Cord-Injured Individuals. Timne course of arterial vascular changes.
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48482.pdf (Publisher’s version ) (Open Access)This thesis presents studies on vascular adaptation to physical inactivity and deconditioning. Although it is clear that physical inactivity is an important risk factor for cardiovascular disease, the underlying physiological mechanisms have not yet been elucidated. In contrast to physical inactivity, exercise decreases the risk for cardiovascular disease. This beneficial effect of exercise is partly due to changes in vascular function and structure. However, far less is known about vascular adaptation to physical inactivity. Therefore, structural and functional changes in both the arterial and venous system in response to deconditioning were studied in models of physical inactivity. Unilateral lower limb suspension, bed rest, and spinal cord injury were applied in this thesis as models of deconditioning. Venous capacitance and occasionally venous compliance decreases after deconditioning and via a reduction in preload may contribute to the reduction in exercise capacity after deconditioning. However, changes in the venous system do not play an important role in the development of orthostatic intolerance after bed rest deconditioning. The baseline and maximal diameter of the leg conduit arteries decreased after ULLS and bed rest deconditioning. Therefore, even short-term adaptation in conduit artery diameter probably represents structural changes due to inward remodeling, rather than functional changes in vascular tone. This is clinically relevant, since inward remodeling contributes importantly to blood vessel obstruction in atherosclerotic disease. Since endothelial dysfunction is prognostic for the occurrence of cardiovascular disease and exercise corrects endothelial dysfunction, information on the effect of physical inactivity on endothelial function is important. Deconditioning does not affect baseline endothelial NO production at the arteriolar level. Moreover, deconditioning enhances both endothelium-dependent and endothelium-independent dilatation of conduit arteries. In contrast, exercise enhances baseline endothelial NO production and selectively increases endothelium-dependent dilatation. Therefore, functional arterial adaptations to inactivity are not simply the inverse of adaptations to exercise.RU Radboud Universiteit Nijmegen, 23 november 2005Promotor : Bindels, R.J.M. Co-promotor : Hopman, M.T.E.210 p
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
Commentaries on viewpoint: pick your Poiseuille: normalizing the shear stimulus in studies of flow-mediated dilation
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Commentaries on viewpoint: pick your Poiseuille: normalizing the shear stimulus in studies of flow-mediated dilation
No full textVariations 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
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
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