1,720,971 research outputs found
A novel software tool to semi-automatically characterize tricuspid valve function and shape using trans-thoracic 3D echocardiography
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
Dynamic three-dimensional evaluation of tricuspid valve morphology and function in patients with pulmonary hypertension
Pulmonary arterial hypertension (PAH) is a common cause of tricuspid valve (TV) dilatation. Because of the impact of PAH on the right ventricle (RV), in-depth understanding of TV morphology and function is important.
Methods: Novel custom software was used to trace and measure TV annulus (TVA) in 10 patients with PH and 10 control subjects (CTRL). To trace the TVA, points were selected in rotated planes and then interpolated. TVA was automatically tracked throughout cardiac cycle. Commissures were identified and used to divide the TVA into three segments. After initialization of the coaptation the TV leaflets were identified. The following parameters were automatically computed in 3D throughout the cardiac cycle: annular area, height, eccentricity and displacement, as well as intercommissural segment lengths.
Results: Compared to CTRL, in patients with PAH, TVA was larger. The TA was also more circular and with less longitudinal displacement. Changes in annular remodeling were not uniform. The anterior and posterior segments were enlarged, while the septal remained unchanged, probably because the septal leaflet is fixed between the fibrous trigones.
Conclusions: This novel software revealed that PAH affects size, shape and function of the TVA, suggesting that 3D analysis may be useful for evaluation of different RV disease states
Relationships between the severity of the regurgitation and the geometry of the tricuspid annulus in patients with functional tricuspid regurgitation
Three-dimensional tricuspid annulus surface area is a better predictor of functional tricuspid regurgitation severity than conventional 2D-echocardiography diameters
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