1,721,148 research outputs found
MELANOCORTIN-1 RECEPTOR VARIANTS IN SKIN CARCINOGENESIS: A POOLED-ANALYSIS
Full text linkBeside the known risk factors for melanoma (environmental UV radiation exposure, fair skin, family history of melanoma, high number of melanocytic nevi, light eye and hair pigmentation), melanocortin-1-receptor (MC1R) gene has been suggested to play a role in melanoma development because it determines skin pigmentation. The aim of my thesis was to create a data-bank of the available information on sporadic skin cancer cases and controls with genetic information on MC1R variants, and to perform a pooled-analysis on MC1R variants, skin cancer, and phenotypic characteristics (M-SKIP Project), using individual patient data. The possibility to perform stratified analysis and to deeply study MC1R-melanoma association would let find different pathways in melanoma development and identify at risk populations.
An Advisory Committee of 10 investigators with great expertise in skin cancer and genetic research was established and the authors of appropriate papers were invited to provide their original published and unpublished data. Data collection started in May 2009 and was closed in December 2010. During this period, 43 investigators were contacted and invited to share data. Thirty-one (72%) agreed to participate and provided data on 28,998 subjects, including 13,511 skin cancer cases (10,182 melanomas) and 15,477 controls from 37 independent published and 2 unpublished studies.
A two stage analysis and a multivariate adaptation of a new approach which took into account the different assessment of confounders in the enclosed studies, were performed to evaluate the main effect of MC1R variants on melanoma development. I found a significant association with melanoma for the five MC1R variants D84E, R142H, R151C, R160W, and D294H by using both the applied approaches. No significant association with melanoma was found for the two not functional MC1R variants V60L and R163Q. Results for the association with melanoma of V92M and I55T variant were still controversial and further investigations is warranted.
In order to study gene-phenotype interaction, I applied logic regression, a method of statistical analysis recently proposed in the genetic field to select combinations of genes mostly associated with a disease. Within the M-SKIP project, I extend the application of this method to the study of both genetic and phenotypic factors, in order to find which combinations of MC1R variants and phenotypic characteristics are mostly associated with melanoma development. The first subgroup included subjects with either atypical naevi or MC1R D294H, who have a more than doubled risk of melanoma than subjects with none of these factors. The second subgroup of high risk subjects included those with either brown eye or more than 45 common naevi. In the validation analysis performed on a larger M-SKIP dataset, however, the association with melanoma for this subgroup of patients was not confirmed. The last high risk subgroup contained subjects with freckles or with intermediate skin type and brown hair or with intermediate skin type and at least one MC1R R151C variant, who had a triple risk of melanoma than subjects without this combination of phenotypic and genetic factors.
In conclusion, among the MC1R variants associated with melanoma, the two variants D294H and R151C seemed the two ones that could indeed increase melanoma risk in combination with phenotypic characteristics and that are warranted to screen
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
Meta-analysis of cancer incidence in children born after assisted reproductive technologies
No full textA meta-analysis was performed on 11 cohort studies of Assisted Reproductive Technologies (ART) and subsequent childhood cancer, published up to February 2005, which reported comparable, nonoverlapping data, and then restricted to eight studies which presented a similar research design. The overall Standardised Incidence Ratio was 1.33 (95% CI 0.62-2.85), and 0.77 (95% CI 0.41-1.42) when the analysis was restricted to eight studies. No evidence of publication bias was observed for the overall analysis. The data are consistent with a lack of increase in risk of childhood cancer, though the amount of data on ART and cancer is still limited; larger multicentric studies as well as a pooled analysis on the available data are warranted
APIKIDS : a cohort of children born after assisted reproductive technologies
No full textA cohort of children born after assisted reproductive technologies (ART) was set up in 2003 in Italy. It aims to follow up the children in order to study the short- and long-term effects of ART. Parents who agreed to participate were contacted for a telephone interview; questions included occupational and non-occupational exposure to carcinogens, reproductive history, history of index pregnancy (including drugs used during pregnancy), delivery and the child's health status. By August 2005, 40 out of the 50 centres contacted (80%) had agreed to participate in the study, and 17 had already sent their data. Information on a total of 2451 cycles ending with a pregnancy are currently available, from 2245 couples. We have contacted 351 of these couples (16%), 309 of whom (88% of the contacts) agreed to participate in the study and were interviewed, while 36 (11%) refused to be interviewed. The total number of children currently included in the database is 411. This study is the first attempt to create a database containing information on children born after ART in Italy. It will provide results on both short- and long-term outcomes in these children
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
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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