1,721,015 research outputs found
Transforming growth factor ? receptor 1 polyalanine polymorphism and exon 5 mutation analysis in breast and ovarian cancer
No full textThe inactivation or altered expression of TGF-ß receptors or other components of the TGF-ß signaling pathway are common in many cancer types. A germ-line sequence variant of transforming growth factor-ß receptor-1 (TßR-I), which involves the deletion of three alanines (6A) from a nine-alanine stretch (9A), has impaired mediation of TGF-ß antiproliferative signaling. The TßR-I (6A) variant has been reported to occur at an increased frequency in a variety of cancer types and may represent an important hereditary predisposing factor. We have investigated the possible influence of the TßR-I (6A) allele on cancer risk in a cases-control study of 248 controls; 304 women with ovarian cancer; 98 women with endometriosis; and 355 women with breast cancer occurring under the age of 40 years, bilateral breast cancer, or a family history of breast cancer. The TßR-I (6A) allele was significantly associated with breast cancer (odds ratio, 1.6; 95% confidence interval, 1.1–2.5). There was no significant association of this allele with ovarian cancers as a whole, although stratifying according to their histological subtype revealed a significant association with the endometrioid and clear-cell cancers (odds ratio, 2.1; 95% confidence interval, 1.2–3.6). Recently a recurrent somatic CTCTGG->CTGCGTGG insertion mutation in exon 5 of TßR-I was reported in >30% of ovarian cancers. If verified, this would indicate that inactivation of TßR-I is a key step in the development of ovarian cancer, perhaps second only to the inactivation of TP53. We analyzed 55 ovarian and 33 breast cancers for mutations using both single-stranded conformational polymorphism/heteroduplex analysis and direct sequencing. No somatic mutations in exon 5 of TßR-I were detected in any case. Our study provides additional evidence for an association of the TßR-I (6A) allele with cancer predisposition, but we find no evidence of a mutational hot-spot in exon 5 of TßR-I in either ovarian or breast cancers.<br/
Identifying DNA markers close to quantitative traits in lepidopteran genomes: Using wing colour variation in Heliconius butterflies as a model
No full text
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
Methylenetetrahydrofolate reductase polymorphism and susceptibility to breast cancer
No full textBackground: A growing body of evidence suggests that variations in the levels of folate may contribute to the development of cancer. A functional polymorphic variant (C?T substitution at nucleotide 677) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene results in the conversion of an alanine to a valine and may modify the risk of breast and other cancers.Method: We have investigated the possible influence of this MTHFR variant on breast cancer risk in a case-control study of 233 healthy women and 335 women who had breast cancer that occurred under the age of 40 years, bilateral breast cancer or a family history of breast cancer.Results: A significant excess of the valine genotypes was observed among the cases (odds ratio 1.43, 95% confidence interval 1.02–2.00). The effect was more pronounced among the cases with a breast cancer diagnosis under the age of 40 years, with an odds ratio of 1.66 (95% confidence interval 1.12–2.41). A nonsignificant excess of the valine genotypes was observed among the cases with a family history of breast cancer or bilateral breast cancer.Conclusions: The low activity C677T (valine) genotype of MTHFR may increase the risk of early onset breast cancer
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
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
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