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The role of spatio-temporal image correlation (STIC) with tomographic ultrasound imaging (TUI) in the sequential analysis of fetal congenital heart disease.
No full textObjective
Spatio-temporal image correlation associated with the tomographic ultrasound imaging mode (TUI-STIC) is a new modality that allows a complete sequential analysis of cardiac structures to be displayed on a single panel by showing all echocardiographic transverse views at the same time. The aims of this study were to identify the best settings for displaying the classic echocardiographic views at different gestational ages and to investigate the role of TUI-STIC in the sequential segmental analysis of complex congenital heart disease (CHD).
Methods
Four-dimensional volumes from 103 cases of confirmed fetal CHD diagnosed and managed at our referral center were evaluated using TUI-STIC. To select the best interslice distance for adequate display of the central cardiovascular connections, each volume was opened and the TUI mode activated, having as a reference the apical four-chamber view. The number of slices was set at nine. The volume was then scrolled until the most significant echocardiographic views were displayed on the screen windows. Then, if too many windows showed intermediate non-diagnostic views, the slice distance was adjusted finely until all key echocardiographic views showed up in the various windows. The interslice distance was regressed against gestational age and the best-fitting curve was identified.
Results
A sequential segmental analysis could be shown with TUI-STIC in all cases. A linear regression equation best fitted the correlation between interslice distance and advancing gestational age (r2 = 0.9042), with the mean interslice distance being 2.7 (SD, 0.3) mm at 19–23 gestational weeks, and 4.0 (SD, 0.4) mm at 30–33 weeks. These settings allowed a complete sequential analysis in all cases.
Conclusions
TUI-STIC allows a complete sequential analysis of CHD in the fetus. The most suitable interslice distances for all gestational ages could be identified. These data may be used while adopting this imaging modality in the four-dimensional evaluation of fetal CHD. Copyright © 2006 ISUOG
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
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