1,721,800 research outputs found
Fluctuation theorem, non linear response and the regularity of time reversal symmetry
Full text linkThe Gallavotti-Cohen fluctuation theorem (FT) implies an infinite set of identities between correlation functions that can be seen as a generalization of Green-Kubo formula to the nonlinear regime. As an application, we discuss a perturbative check of the FT relation through these identities for a simple Anosov reversible system; we find that the lack of differentiability of the time reversal operator implies a violation of the Gallavotti-Cohen fluctuation relation. Finally, a brief comparison to Lebowitz-Spohn FT is reported. (C) 2010 American Institute of Physics. [doi:10.1063/1.3396283
Diabetic retinopathy
No full textEasy observation of the fundus oculi makes retinopathy the most frequently reported chronic complication of diabetes and, consequently, the one we know best in terms of epidemiology and natural history. Achieving near-normal levels of blood glucose and blood pressure provides empirical though powerful tools for clinicians to delay the onset and progression of diabetic retinopathy. Even when these measures have failed and retinopathy becomes sight-threatening, laser photocoagulation has proven remarkably effective. Nonetheless, retinopathy remains a leading cause of blindness and there is little evidence that diabetes-related visual loss is decreasing in industrialized countries. This may result from the mixed blessing of prolonged survival of patients who had become diabetic when metabolic control was pursued less fastidiously than today. Screening for sight-threatening retinopathy is the most cost-effective medical procedure known and should help optimise the use of diagnostic and therapeutic resources, but its widest deployment still meets with inertia and lack of interest within most health care systems. Improving clinical skills and technology, however, allow us to take a more optimistic look at the future, as pathogenesis-targeted forms of treatment are being developed and tested through appropriately powered clinical trials
An Electrostatic Centering Device for Microcomponents
No full textThe paper describes an electrostatic device where a gradient of electrostatic field is able to move microparts to a central zone where they can be easily picked up. The system has demostrated good performances on steel and glass microspheres also in an uncontrolled environment
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
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