1,720,999 research outputs found
Vascular risk factors and rhegmatogenous retinal detachment: A follow-up of a national cohort of Swedish men
Background We aimed to investigate the role of vascular risk factors in the genesis of rhegmatogenous retinal detachment (RRD) using data from a large cohort of Swedish conscripts. Methods We used data from a nationwide cohort of 49 321 Swedish men born during 1949-1951, conscripted for compulsory military service in 1969- 1970 with nearly complete follow-up to 2009. Information on surgically treated RRD between 1973 and 2009 was collected from the National Patient Register. We fitted Cox regression models stratified on myopia degree and including blood pressure levels, body mass index and cigarette smoking. Population attributable fractions of RRD were estimated through maximum likelihood methods. Results We observed 262 cases of RRD in 1 725 770 person-years. At multivariate analysis, the number of cigarettes per day showed a reverse association with the risk of RRD (p for trend 0.01). Conscripts with obesity presented a higher risk compared with normal subjects (adjusted HR 2.51, 95% CI 1.02 to 6.13). We found weak evidence of an association between blood pressure and RRD (HR for men with hypertension compared with normotension 1.41, 95% CI 0.93 to 2.13). All the observed associations were stronger when the analysis was restricted to non-myopic conscripts. In particular, the HR for hypertension was 2.33 (95% CI 1.30 to 4.19) compared with normotension. If this association is causal, we estimated that 42.0% of RRD cases (95% CI 11.5% to 62.0%) occurring among non-myopics are attributable to elevated blood pressure. Conclusions Vascular risk factors may be important determinants of RRD, particularly among non-myopics. Further investigations on the role of hypertension and obesity are needed
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
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
Occupational lifting and rhegmatogenous retinal detachment: A follow-up study of Swedish conscripts
Objectives To investigate the association between occupational lifting and the risk of rhegmatogenous retinal detachment (RRD) using data from a large population of men. Methods We used data from a national cohort of 49 321 Swedish men conscripted for compulsory military service in 1969-1970. We collected information on surgically treated RRD from the National Patient Register and we followed up the cohort between 1991 and 2009 at ages 40-60 years. Exposure to occupational lifting was assessed by applying a job exposure matrix to occupational data from the 1990 census. Incidence rate ratios (IRRs) and 95% CIs were estimated through Poisson regression models adjusted by degree of myopia, income and education level. Results We observed 217 cases of RRD in 7 80 166 person-years. In univariate analyses we did not observe an association between occupational lifting and RRD. However, after adjustment for myopia and socioeconomic factors, we found an increased risk of RRD (IRR 2.38, 95% CI 1.15 to 4.93) for subjects in the highest category of exposure compared with those in the lowest one. The incidence rate of RRD among subjects lifting heavy loads at least twice per week, aged between 50 years and 59 years, and affected by severe myopia was as high as 7.9 cases per 1000 person-years, compared with an overall rate of 0.28. Conclusions Our study supports the hypothesis that heavy occupational lifting is a risk factor for RRD. Information on myopia degree and socioeconomic status is necessary when studying the association between occupational lifting and RRD
Author-wise bibliometric analysis based on entropy.
Author-wise bibliometric analysis based on entropy.</p
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