1,721,081 research outputs found
Realizzazione di uno strumento a matrice di fotoresistori per la mappatura di fasci di radiazione
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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
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
Micro-method for the determination of glutathione in human blood.
No full textA new procedure is described for the visible-range spectrophotometric analysis of glutathione (GSH) in microvolumes of blood (as low as 0.5μL) collected by fingerstick. Samples are diluted 1 to 300 (v/v) in a stabilizing solution, followed by determination of haemoglobin concentration and by acid deproteination. GSH is then measured in the clear supernatant by colorimetry using DTNB, i.e., 5,5'-dithio-bis(2-nitrobenzoic acid), in aqueous solution at pH 7.8. The DTNB reagent is prepared and kept at pH 6.2 until just prior its addition, thus avoiding spontaneous decomposition of the reagent. The assay is rapid, easy to adapt to large-scale studies and it avoids artefactual oxidation of GSH, a common methodological shortcoming. The method is precise with 1.7 to 3.4% intra-day relative standard deviation (RSD) and 2.2 to 4.2% inter-day RSD, and accurate with -1.4% to 2.3% intra-day relative error (RE) and -2.8% to 1.6% inter-day RE. GSH is recovered by 97.5 to 100% at all tested concentrations. The new colorimetric micro-method was validated by a reliable previously reported HPLC method. The procedure is suitable for minimally invasive investigation of oxidative stress in peripheral blood
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
Anethole dithiolethione lowers the homocysteine and raises the glutathione levels in solid tissues and plasma of rats: a novel non-vitamin homocysteine-lowring agent..
No full textHigh homocysteine (Hcys) levels are suspected to contribute to the pathogenesis of cardiovascular disease and of other chronic conditions. Failure of B vitamins to reduce the incidence of cardiovascular events while lowering the Hcys levels, has prompted the search for alternative treatments. We tested the ability of anethole dithiolethione (ADT) to lower the Hcys levels in rats and we explored possible underlying mechanisms. Parenteral administration of 10mg/kg ADT to normal rats for 3 days lowered the Hcys levels between 51.4% and 31.5% in kidneys, liver, testis and plasma. Concomitantly, glutathione (GSH) increased between 112% and 28% in kidneys, brain, liver and plasma whereas protein thiolation index decreased 30%. In hyperhomocysteinemic rats, the plasma Hcys levels dropped 70% following a single ip injection of 10mg/kg ADT, while they decreased 55% following oral administration of 2mg/kg/day ADT for one week. Significant additive effects occurred when sub-therapeutic doses of ADT and folic acid were used in combination. To test the possible mechanism(s) of these actions, we perfused isolated rat livers and kidneys with albumin-bound Hcys, the prevalent form of plasma Hcys, and physiological thiols and disulfides at different ratios. In both organ preparations, the elimination rate of albumin-bound Hcys was progressively faster as the amount of reduced thiols was increased in the perfusate. These findings indicate that ADT shifts the redox ratio of GSH and other thiols with their oxidized forms toward the reduced forms, thus favoring the dissociation of albumin-bound Hcys and its transfer to renal and hepatic cells for further processing
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