1,721,000 research outputs found
A prospective ultrasound study of whole blood metals and incidence of uterine leiomyomata
Get PDFBackground: Uterine leiomyomata (UL), hormone-dependent neoplasms, are a major source of gynecologic morbidity. Metals are hypothesized to influence UL risk through endocrine disruption, and their effects may vary by vitamin D status. Objective: We estimated associations of a metal mixture with incident UL, overall and by vitamin D status. Methods: We analyzed data from the Study of Environment, Lifestyle and Fibroids, a Detroit-area prospective cohort study of 1,693 Black women aged 23-35 years. We measured concentrations of 17 metals/metalloids in whole blood and 25-hydroxyvitamin D (25[OH]D) in serum collected at baseline (2010-2012). Participants underwent ultrasonography at baseline and after 20 months to detect UL. We used Bayesian Kernel Machine Regression to estimate adjusted associations (β) of the metal mixture with probit of incident UL. We also ran Cox regression models with interaction terms to estimate incidence rate ratios (IRR) by vitamin D status. Results: Among 1,132 UL-free participants at baseline, 832 (73%) had vitamin D deficiency (25[OH]D<20 ng/mL) and 117 (10%) developed UL within 20 months. Increasing all metals from their 50th to 75th percentiles was weakly positively associated with UL overall (β=0.06, 95% credible interval [CrI]: -0.03, 0.16) and among vitamin D-deficient participants (β=0.13, 95% CrI: 0.01, 0.24), driven by cadmium (overall and vitamin D-deficient) and mercury (vitamin D-deficient only). Increasing cadmium from its 25th to 75th percentile was positively associated with UL overall (β=0.03, 95% CrI: -0.05, 0.11) and among vitamin D-deficient participants (β=0.13, 95% CrI: 0.02, 0.24). In Cox models, cadmium (IRR=1.55, 95% confidence interval [CI]: 1.07, 2.24, per 1-unit increase in standardized concentration) and mercury (IRR=1.38, 95% CI: 0.99, 1.92) were positively associated with UL among vitamin D-deficient participants. Discussion: The metal mixture was positively associated with incident UL, but the association was weak and imprecise. We observed a stronger association among vitamin D-deficient participants that was driven by cadmium and mercury. https://doi.org/10.1289/EHP15218
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
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
Variations in Inflammatory and Cell Cycle Genes and Preterm Birth, Small for Gestational Age and Hypertensive Disorders of Pregnancy
Get PDFThe maternal outcome of preeclampsia and the fetal outcomes of preterm birth and poor intrauterine growth often occur together, share placental pathology and are marked by changes in inflammatory biomarkers. Genetic polymorphisms in inflammatory genes have been investigated with respect to all of these outcomes with conflicting results. In previous studies case groups have been small or non-representative of US populations, and coverage of candidate genes has been sparse. We sought to expand coverage of inflammatory genes related to natural killer cells and T cells and in addition included candidate genes related to cell cycle function. In a sample of 1646 women from a bi-racial prospective pregnancy cohort, we examined the relationship between 503 tagSNPs in 40 genes and the outcomes of preterm birth, small for gestational age, gestational hypertension and preeclampsia. Six genes involved in natural killer cell function (IL12A, CSF2, IFNGR2 and KIR3DL2) and Th2 immunity (IL13 and IL4) were associated with preterm birth among European Americans with some evidence of an association for African Americans as well (IL12A and CSF2). IL6 and KLRD1 were associated with term small for gestational age births among African Americans with similar results for IL6 alone among European Americans. LTA, TNF and TBKBP1 were associated with preeclampsia among European Americans only. There were no associations with any cell cycle genes or with the outcome of gestational hypertension. In summary, this study found novel associations with a number of genes related to natural killer cells, Th2 immunity and TNF signaling pathways and the outcomes of preterm birth, poor fetal growth and preeclampsia among both European and African Americans.Doctor of Philosoph
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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