1,720,956 research outputs found
The natural history of gallstones: the GREPCO experience
No full textDuring the cross-sectional studies (February 1981 to July 1984) performed by the Group for Epidemiology and Prevention of Cholelithiasis (GREPCO) in Rome, Italy, 161 subjects were identified as having gallstones. Ten subjects did not participate in the prospective follow-up. At entry, 33 of the 151 remaining subjects were symptomatic, and 118 were asymptomatic. Data on incidence of biliary colics, complications, cholecystectomy, and death were collected at least every 2 years. In the initially asymptomatic group, the cumulative probability (% +/- SE) of developing biliary colic was 11.9 +/- 3.0 at 2 years, 16.5 +/- 3.5 at 4 years, and 25.8 +/- 4.6 at 10 years. None of the variables considered as possible modifiers of the natural history were found to be associated with an increased risk of developing biliary colic. The cumulative probability (% +/- SE) of developing complications after 10 years was 3.0 +/- 1.8 in the initially asymptomatic group and 6.5 +/- 4.4 in the symptomatic group (P = NS). Incidence of cholecystectomy was higher in the initially symptomatic than in the asymptomatic group (log-rank test = 2.27; P = .02). Fifteen (53.6%) of the 28 operated in the initially asymptomatic group were submitted to cholecystectomy, although specific symptoms did not occur. Twelve (10.2%) and 2 (6.1%) of the initially asymptomatic and symptomatic subjects died during the follow-up. One patient in the former group died at age 64 of a histologically proven adenocarcinoma of the gallbladder. In conclusion, this study demonstrates that the natural history of gallstones is less benign than is generally considered
The epidemiology of gallstone disease in Rome, Italy. Part II. Factors associated with the disease. The Rome Group for Epidemiology and Prevention of Cholelithiasis (GREPCO).
No full textAbstract
The epidemiological associations of gallstone disease were evaluated in a population of 2,325 civil servants (1,244 men and 1,081 women) in Rome, Italy, which was enrolled in a cross-sectional survey on cholelithiasis. Participants were screened for the presence of gallstones by gallbladder ultrasonography, completed a questionnaire on family and personal history and underwent a physical examination and blood chemistry. Statistically significant associations were established by univariate analysis of the age-standardized data and by step-wise multiple logistic regression. At univariate analysis, increasing age, serum triglycerides and number of cigarettes smoked per day, and decreasing high-density lipoprotein-cholesterol were the conditions associated with the presence of gallstones in men. Age and parity were the correspondent associations in women. After controlling by multiple logistic regression, a different pattern of associated conditions emerged. In men, only age and serum triglycerides showed a significant positive association with gallstones, which was independent of other variables. In women, the presence of gallstones was independently associated with increasing age, number of pregnancies, body mass index and serum triglycerides, and with decreasing total (and low-density lipoprotein) cholesterol. The latter association was curvilinear in shape. The conditions associated with a history of cholecystectomy differed from those observed in subjects with gallstones, with the exceptions of age, in both sexes, and high serum triglycerides, in women. Fasting blood glucose levels were higher in women with a history of cholecystectomy than in those with or without gallstones, both at univariate and multiple logistic regression analyses.(ABSTRACT TRUNCATED AT 250 WORDS
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
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
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