1,720,998 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
Prognostic Relevance of Left Ventricular Myocardial Performance After Transcatheter Aortic Valve Replacement
Full text linkBACKGROUND:
The left-ventricular myocardial performance index Tei is an echocardiographic parameter that incorporates the information of systolic and diastolic time intervals. While the prognostic value of selected systolic and diastolic parameters is well established after transcatheter aortic valve replacement, the role of Tei has not been evaluated in this setting.
METHODS AND RESULTS:
Between August 2007 and December 2015, consecutive patients with symptomatic, severe aortic stenosis and transthoracic echocardiography pre- and post-transcatheter aortic valve replacement were considered eligible for this analysis. The primary end point was all-cause mortality at 1 year after transcatheter aortic valve replacement. Of 824 patients with echocardiographic images to calculate Tei, pre-Tei was normal (<0.45) in 639 and high (≥0.45) in 185, whereas post-Tei was normal in 602 and high in 120, respectively. After adjustment for confounding factors, high pre-Tei was associated with an increased risk of all-cause mortality at 30 days (adjusted hazard ratio [HRadj] 3.62; 95% CI, 1.89-6.91) and 1 year (HRadj 2.56; 95% CI, 1.78-3.69). Similarly, post-Tei was associated with an increased risk of mortality between 30 days and 1-year follow-up (HRadj 6.70; 95% CI, 4.22-10.63). At multivariable analysis Tei emerged as an independent predictor of early (pre-Tei index per 0.1-HRadj 1.40; 95% CI, 1.23-1.60) and late mortality (post-Tei index per 0.1-HRadj 1.40; 95% CI, 1.31-1.50), respectively.
CONCLUSIONS:
The left-ventricular myocardial performance index Tei is associated with impaired clinical outcomes during short- and longer-term follow-up after transcatheter aortic valve replacement
Effect of statins and non-statin LDL-lowering medications on cardiovascular outcomes in secondary prevention: A meta-analysis of randomized trials
Full text linkAIMS:
Current evidence on dyslipidaemia management has expanded to novel treatments and very low achieved levels of low-density lipoprotein cholesterol (LDL-C). We sought to compare the clinical impact of more-intensive vs. less-intensive LDL-C lowering by means of statins and currently recommended non-statin medications in secondary prevention.
METHODS AND RESULTS:
We searched Medline, EMBASE, and Cochrane databases for randomized controlled trials of statins, ezetimibe, proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors, or bile acid sequestrants with >500 patients followed for ≥1 year. We employed random-effects models using risk ratios (RRs) with 95% confidence intervals (CIs) to compare outcomes. We included 19 trials (15 of statins, 3 of PCSK9 inhibitors, and 1 of ezetimibe) with 152 507 patients randomly assigned to more-intensive (n = 76 678) or less-intensive treatment (n = 75 829). More-intensive treatment was associated with 19% relative risk reduction for the primary outcome, major vascular events (MVEs; RR 0.81, 95% CI 0.77-0.86). Risk reduction was greater across higher baseline levels and greater achieved reductions of LDL-C. The clinical benefit was significant across varying types of more-intensive treatment and was consistent for statins (RR 0.81, 95% CI 0.76-0.86) and non-statin agents (PCSK9 inhibitors and ezetimibe; RR 0.85, 95% CI 0.77-0.94) as active (more-intensive) intervention (P-interaction = 0.38). Each 1.0 mmol/L reduction in LDL-C was associated with 19% relative decrease in MVE. Death, cardiovascular death, myocardial infarction, stroke, and coronary revascularization also favoured more-intensive treatment.
CONCLUSION:
Reduction of MVE is proportional to the magnitude of LDL-C lowering across a broad spectrum of on-treatment levels in secondary prevention. Statin intensification and add-on treatment with PCSK9 inhibitors or ezetimibe are associated with significant reduction of cardiovascular morbidity in this very high-risk population
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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