1,721,004 research outputs found
Large breast size as a risk factor for late adverse effects of breast radiotherapy: is residual dose inhomogeneity, despite 3D treatment planning and on delivery, the main explanation? on behalf of the FAST Trialists’ Group.
No full textBackground and PurposeLarge breast size is associated with an increased risk of late adverse effects after breast conservation surgery and radiotherapy, even when 3D dosimetry is used. The purpose of this study is to test the hypothesis that residual dose inhomogeneity is sufficient to explain the association.MethodsPatients previously treated after breast conservation surgery with whole breast radiotherapy using 3D dosimetry and followed up in the UK FAST hypofractionation trial were selected for this analysis. The residual level of dose inhomogeneity across the whole breast treatment volume was used to test for association between residual dosimetry and post-treatment change in breast appearance at 2?years post-radiotherapy.ResultsAt 2?years, 201/279 (72%) of women had no change in photographic breast appearance, 61 (22%) had mild change and 17 (6%) had marked change. Breast size and dosimetry were both significantly associated with late effects in univariate analyses, but only breast size remained an independent significant risk factor for change in breast appearance when included in a multiple regression model together with other prognostic factors (p?=?0.006 for trend).ConclusionLarge-breasted women are more likely to suffer change in breast size and shape after whole breast radiotherapy delivered using 3D dosimetry, but residual dose inhomogeneity is insufficient to explain the association
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
Test of association between variant TG?1 alleles and late adverse effects of breast radiotherapy
No full textPurpose: to test for association between single nucleotide polymorphisms at the TGF?1 locus and the risk of late normal tissue injury following whole breast radiotherapy.Methods: a retrospective study compared the number of variant alleles at ?509 and codons 10 and 25 of the TGF?1 locus in women followed up in two prospective clinical trials who developed either marked radiotherapy adverse effects or no adverse effects after matching on fractionation schedule, breast size, surgical deficit, chemotherapy and length of follow up.Results: median follow up in the two trials was 7.4 (maximum 15) years and 5.3 (maximum 5.3) years. 1237/1716 (72%) women with photographic assessments of radiotherapy adverse effects were alive and well, and 147/1237 (12%) potential cases with the most marked change in photographic change in breast appearance were matched to potential controls recording no change. In an unmatched analysis of 82 cases and 108 controls, no significant difference in the number of genetic variants was observed.Conclusions: no association was detected between sequence variations at the TGF?1 locus and the risk of late adverse effects of breast radiotherap
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