1,721,010 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
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
Myocardial blood flow and fibrosis in hypertrophic cardiomyopathy
No full textAbstract
BACKGROUND:
We investigated the relationship between myocardial blood flow (MBF), fibrosis, risk factors for sudden death, and clinical manifestations in hypertrophic cardiomyopathy (HCM).
METHODS AND RESULTS:
Sixty-two patients with HCM (45 men, overall mean age 47 ± 16 years), 15 acromegalic patients with left ventricular hypertrophy (9 man, overall mean age 47 ± 12 years), and 20 healthy subjects underwent cardiac magnetic resonance. Resting MBF was measured as the ratio between coronary sinus flow measured by phase-contrast technique and left ventricular mass. Myocardial fibrosis was evaluated by late gadolinium enhancement (LGE) technique. In HCM patients, MBF was significantly lower than in control subjects and acromegalic patients. Patients with LGE had lower MBF than those without it (0.46 ± 0.2 vs 0.66 ± 0.29 mL·min(-1)·g(-1); P < .005). Patients with ventricular tachycardia at Holter monitoring had lower MBF (0.4 ± 0.14 vs 0.6 ± 0.29 mL·min(-1)·g(-1); P < .04). Among patients with preserved systolic function, those in New York Heart Association (NYHA) functional class ≥II had lower MBF than those in NYHA functional class I (0.46 ± 0.2 vs 0.69 ± 0.3 mL·min(-1)·g(-1); P < .003). MBF was the only independent predictor of worse clinical status (NYHA ≥II; P = .01).
CONCLUSIONS:
In HCM patients low resting MBF is associated with the presence of fibrosis. MBF is a predictor of worse clinical status
Cardiac magnetic resonance predicts outcome in patients with premature ventricular complexes of left bundle branch block morphology
No full textObjectives We investigated whether the presence of right ventricular (RV) abnormalities detected by cardiovascular magnetic resonance (CMR) predict adverse outcome in patients presenting with frequent premature ventricular complexes (PVCs) of left bundle branch block (LBBB) morphology. Background CMR is a component of the diagnostic workup for the differential diagnosis between arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) and idiopathic RV tachycardia. RV abnormalities evaluated by CMR could have prognostic importance. Methods Four hundred forty consecutive patients with >1,000 PVCs of LBBB morphology (minor diagnostic criterion of ARVC/D) and no other pre-existing criteria were prospectively enrolled. RV wall motion (WM), signal abnormalities, dilation, and reduced ejection fraction evaluated by CMR were considered imaging criteria of ARVC/D. Follow-up was performed evaluating an index composite end point of 3 cardiac events: cardiac death, resuscitated cardiac arrest, and appropriate implantable cardiac-defibrillator shock. Results Subjects with multiple RV abnormalities (RVA-2 group) had worse outcome than the no-RVA group (hazard ratio [HR]: 48.6; 95% confidence interval [CI]: 6.1 to 384.8; p < 0.001). Of the 61 patients in the RVA-2 group, only 6 had a definite diagnosis of ARVC/D applying the Task Force Criteria. Also, subjects with a single imaging criterion (RVA-1 group) had worse outcome than the no-RVA group (HR: 18.2; 95% CI: 2.0 to 162.6; p = 0.01). Patients with only WM abnormalities had higher prevalence of cardiac events than no-RVA (HR: 27.2; 95% CI: 3.0 to 244.0; p = 0.03). Conclusions In subjects with frequent PVC of LBBB morphology, CMR allows risk stratification. RV abnormalities were associated with worse outcome. © 2010 American College of Cardiology Foundation
Usefulness of india ink artifact in steady-state free precession pulse sequences for detection and quantification of intramyocardial fat
No full textPurpose In steady state free precession (SSFP) images acquired with a repetition time/echo time (TR/TE) ≈ 2, fat is surrounded by a black boundary, called "India Ink" artifact. Indian Ink artifact may improve detection of intramyocardial fat. Aims of this study were: (i) to assess the accuracy of SSFP technique for the detection of fat metaplasia in remote myocardial infarction (RMI); (ii) to evaluate the inter- and intraobserver reproducibility for the quantification of intramyocardial fat using SSFP and fast spin echo/short TI inversion recovery (FSE/STIR) techniques. Materials and Methods A total of 200 patients (age 64 ± 10 years) with RMI (>1000 days) underwent MRI using a 1.5 Tesla (T) scanner. SSFP images (with a TR/TE ≈2), FSE and STIR images were acquired in short and long axis views. Fat was detected in FSE/STIR and SSFP images and its extent manually measured. The inter- and intraobserver agreement for the quantification of fat metaplasia using both the SSFP image and the FSE images was evaluated. Results Left ventricle intramyocardial fat was detected in SSFP images of 95 patients (47.5%) and in FSE/STIR images of 84 patients (42%). A very good agreement was found using the SSFP technique between investigators. Conclusion SSFP sequence with TR/TE=2 is a valuable technique for identifying and quantifying the presence of fat tissue within the left ventricle myocardium in RMI. © 2013 Wiley Periodicals, Inc. © 2013 Wiley Periodicals, Inc
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
- …
