1,721,233 research outputs found
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
On the origin and the consequences of circadian abnormalities in patients with cirrhosis.
OBJECTIVES: Plasma melatonin profile abnormalities have been described in patients with cirrhosis and generally attributed to impaired hepatic melatonin metabolism. The possibility that they might reflect circadian clock dysfunction has not been explored. In addition, the relationship between plasma melatonin profiles and the sleep disturbances observed in these patients remains unclear. The aims of this study were: (i) to evaluate circadian clock function and hepatic melatonin metabolism in cirrhotic patients, and (ii) to study the relationship between plasma melatonin profiles and sleep-wake behavior. METHODS: The study population comprised 20 patients with cirrhosis (mean (range) age, 59 (39-77) years) and 9 healthy volunteers (60 (38-84) years). Plasma melatonin/cortisol concentrations were measured hourly, for 24 h, in light/posture-controlled conditions. Urinary 6-sulfatoxymelatonin, the main melatonin metabolite, was measured simultaneously to determine clearance. The ability of light to suppress nocturnal melatonin synthesis was assessed. Habitual sleep quality/timing was evaluated using a questionnaire, actigraphy, and sleep diaries. RESULTS: There was evidence of central circadian disruption in patients compared with healthy controls: peak plasma melatonin/cortisol times were delayed (04:48+/-02:36 vs. 02:48+/-00:54, P=0.01; 10:18+/-02:54 vs. 08:54+/-01:24, P=0.06) and the plasma melatonin response to light was reduced (12%+/-19% vs. 24%+/-15%, P=0.09). However, the mean 24 h plasma melatonin clearance did not differ significantly between patients and healthy volunteers (0.22+/-0.10 vs. 0.28+/-0.17 l/kg per h, P=0.36). Finally, although patients showed a degree of misalignment between sleep and circadian timings, there was no association between circadian abnormalities and impaired sleep quality. CONCLUSIONS: Plasma melatonin profile abnormalities, predominantly central in origin, are observed in patients with mild to moderately decompensated cirrhosis. However, they are substantially unrelated to the sleep disturbances prevalent in this population
Sleep and circadian abnormalities in patients with cirrhosis: features of delayed sleep phase syndrome?
Night-time sleep disturbance does not correlate with neuropsychiatric impairment in patients with cirrhosis.
Sleep-wake patterns in patients with cirrhosis: all you need to know on a single sheet. A simple sleep questionnaire for clinical use.
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
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