1,721,060 research outputs found
Comparative effects of rosuvastatin and aspirin on vascular collagen deposit in stroke-prone rats (SHRSP)
Renal iron deposition and stroke : a longitudinal MRI study in SHRSP
Background and Purpose - Oxidative stress plays a pivotal role in the pathogenesis of renal and cerebrovascular injury in salt-loaded stroke-prone spontaneously hypertensive rat (SHRSP)1,2. Our preliminary data showed an iron accumulation in the kidney of SHRSP before stroke appearance. Thus, the aim of the study was to characterize by magnetic resonance imaging (MRI) the renal iron deposition in a longitudinally in vivo study and to determine the role of iron on the pathological events occurring in SHRSP.
Methods and Results - SHRSP fed a high-salt diet were treated subcutaneously with vehicle or 200 mg/kg/day of deferoxamina (DFO) an iron chelator. The vehicle-treated rats developed hypertension, stroke, proteinuria and kidney morphological alterations. Renal iron accumulation visualized by MRI using a gradient echo sequence was detected after established proteinuria and before stroke appearance. Iron histological staining (Perls’) correlated with the T2* MR signal intensity (MRSI) data, indicating that the signal reduction in the MR images was due to the presence of iron. Interestingly, MRSI of the renal cortex was found to decrease with the progression of kidney disease. Vehicle-treated SHRSP showed decreased haematocrit, serum haptoglobin depletion and haematological alterations, suggesting an involvement of hemolytic process in the renal iron accumulation. Control animals developed systemic oxidative stress and renal mitochondrial dysfunction. DFO treatment delayed stroke appearance, prevented renal iron accumulation and preserved renal physiology and morphology. These beneficial effects seems mainly to be related to the ability of DFO to reduce free-iron derived from hemolysis and to its anti-oxidant proprieties.
Conclusions - We found, in this longitudinally in vivo study, that kidney T2* could be considered as a biomarker for renal iron accumulation. Our data, for the first time, support the involvement of iron in the development of renal and brain damage in salt-loaded SHRS
Going Beyond Counting First Authors in Author Co-citation Analysis
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
“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
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
Analysis of regional left ventricular function in the post-infarct mouse by magnetic resonance imaging with retrospective gating.
Dispelling the Myths Behind First-author Citation Counts
We 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
We 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
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