1,720,988 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Sensitivity of Myocardial Stiffness Estimates to Inter-observer Variability in LV Geometric Modelling
No full textHeart failure is known to be associated with substantial changes in the mechanical properties of the heart muscle. Biomechanical parameters, such as myocardial stiffness, have the potential to help clinicians diagnose and determine and monitor treatment options. The impact of inter-observer variability of geometric modelling on the estimation of passive myocardial stiffness has not yet been systematically investigated. We aimed to examine the sensitivity of myocardial stiffness estimates with respect to inter-observer geometric model variability. Twenty-four subjects (5 controls, 19 patients with heart failure) underwent left heart catheterisation and cardiovascular magnetic resonance (CMR) imaging. Three expert analysts independently constructed three-dimensional geometric models of the left ventricle (LV), which were used to estimate myocardial stiffness using finite element simulations that combined cine CMR data and LV pressure measurements. Bland-Altman analysis was used to assess the inter-observer effects on the reproducibility of myocardial stiffness. The inter-observer variations were ±7.69 mL/m2 and ±9.78 g/m2 for the LV end-diastolic volume and mass indices, respectively. Meanwhile, the variability ranged by up to ±0.51 kPa for inter-observer analysis on the estimated intrinsic myocardial stiffness values. Findings from this pilot study highlight the importance of the accuracy of image-based geometric modelling when estimating myocardial stiffness.</p
In Vivo Pressure-Volume Loops and Chamber Stiffness Estimation Using Real-Time 3D Echocardiography and Left Ventricular Catheterization – Application to Post-heart Transplant Patients
No full textIn vivo pressure-volume loops (PVLs) are the gold standard measurement to assess ventricular function. We developed a pipeline to integrate hemodynamic measurements with real-time three-dimensional (3D) echocardiographic data to construct in vivo PVLs for 25 post-heart transplant patients. We then evaluated left ventricular diastolic function for these patients by calculating chamber stiffness from a cubic polynomial fit of the diastolic pressure-volume relationships (PVR). We examined the ability of a well-established mathematical (Klotz) model to predict the patient-specific diastolic PVRs. We found that beat-to-beat variation in hemodynamic measurement was typical for this group of patients, which resulted in mean ± standard deviation end-diastolic chamber stiffness estimates of 0.75 ± 0.40 mmHg/ml. The cubic polynomial fits of the individual diastolic PVRs resulted in much smaller errors (0.25 ± 0.01 mmHg) compared to those associated with the Klotz predicted diastolic PVRs (4.0 ± 0.27 mmHg), which provided a poor representation of the in vivo diastolic PVRs. The proposed framework enables the temporal alignment between hemodynamic and 3D imaging data to produce in vivo PVLs that can be used not only to quantify global ventricular function, but also to estimate mechanical properties of the myocardium.</p
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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