1,721,132 research outputs found
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
Influence of clofibrate on serum triptophan in man
No full textThe effect of clofibrate on free and bound tryptophan levels was tested in 8 volunteers, 5 of whom were hospitalised. Comparing the effects of the drug, administered for 5 days, with those of a placebo, given for 5 further days, after an interval of 2 days, it was observed that clofibrate lowered total plasma tryptophan by 50-70% in all subjects. The decrease is in the bound fraction and probably reflects a displacement due to the high protein binding affinity of the drug. At the same time plasma free tryptophan values increase significantly. These data confirm our previous observations in the rat, demonstrating a decrease of bound plasma tryptophan and an increase of brain tryptophan and 5-HIAA levels, and supporting the hypothesis that clofibrate increased the availability of tryptophan to brain tryptophan hydroxylase, thus stimulating serotonin synthesis
Glycosylated hemoglobins and the oxygen affinity in whole blood
No full textThe pO2 at which haemoglobin is half-saturated with oxygen (p50) was determined at fixed pCO2 (45 mmHg) and without altering the resulting pH and the level of organic phosphates in heparinized whole blood samples from 26 diabetic patients and 24 normal subjects of both sexes. Diabetic blood p50 was higher (29.79 +/- 1.68 versus 28.26 +/- 1.16 mmHg, p less than 0.001) and with a higher 2,3-diphosphoglyceric acid/haemoglobin molar ratio (1.04 +/- 0.15 versus 0.86 +/- 0.10, p less than 0.001). The pH at a pCO2 of 45 mmHg was the same in the two groups. The observed p50 values were compared with those obtained after normalization in respect to pH and the level of 2,3-diphosphoglyceric acid. We conclude that glycosylated haemoglobins, known to have an increased affinity for oxygen when purified and in diluted solutions, do not play a significant role in the oxygen affinity pattern of diabetics at the concentrations normally found in vivo
Dietary selenium and zinc intake and the medium-term Se and Zn status in obese persons on low-calorie diets
No full textThe Se and Zn content of several foodstuffs collected in Northern Italy was evaluated by Atomic Absorption Spectrometry, these foodstuffs, employed in markedly hypocaloric diets with high fiber content, were utilized in the medium-term treatment of obesity. The plasma and erythrocyte selenium and zinc contents were evaluated in sixteen non-hospitalized obese patients over a 6-week period. Dietary regimens of 700 Kcal/day for 21 days followed by 1050 Kcal/day for 42 days were imposed. In spite of the drastic reduction in calorie intake, significant elevations in plasma (p less than 0.05) and erythrocytes (p less than 0.005) Se were observed after 9 weeks of treatment; plasma Zn, on the contrary, shows a slight but significant reduction (p less than 0.05) at the end of the experimental period. Findings suggest that, from the point of view of the microelement status, the balanced low-calorie diet with high fiber content is a mild, but quite adequate method for the treatment of subjects in good health even for long periods
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
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