1,448 research outputs found

    Donor-specific Cell-based Assays in Studying Sensitivity to Low-dose Radiation: A Population-based Perspective

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    Currently, a linear no-threshold model is used to estimate health risks associated with exposure to low-dose radiation, a prevalent exposure in the general population, because the direct estimation from epidemiological studies suffers from uncertainty. This model has been criticized based on unique biology of low-dose radiation. Whether the departure from linearity is toward increased or decreased risk is intensely debated. We present an approach based on individual radiosensitivity testing and discuss how individual radiosensitivity can be assessed with the goal to develop a quantifiable measure of cellular response that can be conducted via high-throughput population testing

    Hepatic effects of tartrazine (E 102) after systemic exposure are independent of oestrogen receptor interactions in the mouse

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    Tartrazine is a food colour that activates the transcriptional function of the human oestrogen receptor alpha in an in vitro cell model. Since oestrogens are cholestatic, we hypothesised tartrazine will cause periportal injury to the liver in vivo. To test this hypothesis, tartrazine was initially administered systemically to mice resulting in a periportal recruitment of inflammatory cells, increased serum alkaline phosphatase activity and mild periportal fibrosis. To determine whether an oestrogenic effect may be a key event in this response, tartrazine, sulphonated metabolites and a food additive contaminant were screened for their ability to interact with murine oestrogen receptors. In all cases, there were no interactions as agonists or antagonists and further, no oestrogenicity was observed with tartrazine in an in vivo uterine growth assay. To examine the relevance of the hepatic effects of tartrazine to its use as a food additive, tartrazine was orally administered to transgenic NF-κB-Luc mice. Pre- and concurrent oral treatment with alcohol was incorporated given its potential to promote gut permeability and hepatic inflammation. Tartrazine alone induced NF- κB activities in the colon and liver but there was no periportal recruitment of inflammatory cells or fibrosis. Tartrazine, its sulphonated metabolites and the contaminant inhibited sulphotransferase activities in murine hepatic S9 extracts. Given the role of sulfotransferases in bile acid excretion, the initiating event giving rise to periportal inflammation and subsequent hepatic pathology through systemic tartrazine exposure is therefore potentially associated an inhibition of bile acid sulphation and excretion and not on oestrogen receptor-mediated transcriptional function. However, these effects were restricted to systemic exposures to tartrazine and did not occur to any significant effect after oral exposure

    Toward an understanding of risk factors for binge-eating disorder in black and white women: A community-based case-control study

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    This study sought to identify in white women risk factors specific to binge-eating disorder (BED) and for psychiatric disorders in general, and to compare black and white women on risk factors for BED.

    Know Your Value: Negotiation Skill Development for Junior Investigators in the Academic Environment—A Report from the American Society of Preventive Oncology\u27s Junior Members Interest Group

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    The American Society of Preventive Oncology (ASPO) is a professional society for multidisciplinary investigators in cancer prevention and control. One of the aims of ASPO is to enable investigators at all levels to create new opportunities and maximize their success. One strategy adopted by ASPO was to develop the Junior Members Interest Group in 1999. The Interest Group membership includes predoctoral fellows, postdoctoral fellows, and junior faculty members who are provided career development and training opportunities (1). Responsibilities of the members of the Junior Members Interest Group include serving on the ASPO Executive Committee and the Program Planning Committee and organizing professional development sessions at ASPO\u27s annual meeting. As part of the 2014 ASPO annual meeting, the Junior Members Interest Group organized a session entitled “Negotiation Skill Development for Junior Investigators in the Academic Environment.” This interactive session was designed to provide early-career investigators an opportunity to practice their negotiation skills and to receive expert advice and strategies to effectively negotiate new faculty positions in an academic environment. The session focused primarily on negotiating an initial academic appointment from a graduate student or postdoctoral fellow to an assistant professor–level position. In addition to the main focus, the session also covered renegotiation for assistant and associate-level investigators as they navigate through their careers. The session began with an interactive exercise led by Dr. Stephanie A.N. Silvera (Associate Professor of Public Health, Montclair State University, Montclair, NJ) where participants engaged in a mock salary negotiation session with another member of the audience (Table 1). Following the negotiation exercise, Dr. Silvera led a debriefing session. Next, four panelists at different levels in their academic careers were invited to provide their personal perspectives on the topic of effective negotiation: Dr. Faith Fletcher (Assistant Professor of Community Health Sciences, the University of Illinois at Chicago, Chicago, IL) to provide the perspective of a first-year faculty member; Dr. Stephanie A.N. Silvera (Associate Professor of Public Health, Montclair State University, Montclair, NJ) to provide the perspective of a recently tenured faculty member; Dr. Karen Basen-Engquist (Professor of Behavioral Science and Director of the Center for Energy Balance, University of Texas MD Anderson Cancer Center, Houston, TX) to provide the perspective of a senior faculty member; and Dr. Peter G. Shields (Professor and Deputy Director of the Ohio State University Comprehensive Cancer Center, Columbus, OH) to provide the perspective of a senior faculty member with extensive experience on the employer side of an academic appointment negotiation. This report summarizes the main themes that emerged from the negotiation exercise debriefing, the speakers\u27 advice and recommendations, and responses to audience questions during the session

    Recognizing Treelike k-Dissimilarities

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    A k-dissimilarity D on a finite set X, |X| >= k, is a map from the set of size k subsets of X to the real numbers. Such maps naturally arise from edge-weighted trees T with leaf-set X: Given a subset Y of X of size k, D(Y) is defined to be the total length of the smallest subtree of T with leaf-set Y . In case k = 2, it is well-known that 2-dissimilarities arising in this way can be characterized by the so-called "4-point condition". However, in case k > 2 Pachter and Speyer recently posed the following question: Given an arbitrary k-dissimilarity, how do we test whether this map comes from a tree? In this paper, we provide an answer to this question, showing that for k >= 3 a k-dissimilarity on a set X arises from a tree if and only if its restriction to every 2k-element subset of X arises from some tree, and that 2k is the least possible subset size to ensure that this is the case. As a corollary, we show that there exists a polynomial-time algorithm to determine when a k-dissimilarity arises from a tree. We also give a 6-point condition for determining when a 3-dissimilarity arises from a tree, that is similar to the aforementioned 4-point condition.Comment: 18 pages, 4 figure

    The institutional shaping of management: in the tracks of English individualism

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    Globalisation raises important questions about the shaping of economic action by cultural factors. This article explores the formation of what is seen by some as a prime influence on the formation of British management: individualism. Drawing on a range of historical sources, it argues for a comparative approach. In this case, the primary comparison drawn is between England and Scotland. The contention is that there is a systemic approach to authority in Scotland that can be contrasted to a personal approach in England. An examination of the careers of a number of Scottish pioneers of management suggests the roots of this systemic approach in practices of church governance. Ultimately this systemic approach was to take a secondary role to the personal approach engendered by institutions like the universities of Oxford and Cambridge, but it found more success in the different institutional context of the USA. The complexities of dealing with historical evidence are stressed, as is the value of taking a comparative approach. In this case this indicates a need to take religious practice as seriously as religious belief as a source of transferable practice. The article suggests that management should not be seen as a simple response to economic imperatives, but as shaped by the social and cultural context from which it emerges

    Reverse Engineering Gene Networks with ANN: Variability in Network Inference Algorithms

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    Motivation :Reconstructing the topology of a gene regulatory network is one of the key tasks in systems biology. Despite of the wide variety of proposed methods, very little work has been dedicated to the assessment of their stability properties. Here we present a methodical comparison of the performance of a novel method (RegnANN) for gene network inference based on multilayer perceptrons with three reference algorithms (ARACNE, CLR, KELLER), focussing our analysis on the prediction variability induced by both the network intrinsic structure and the available data. Results: The extensive evaluation on both synthetic data and a selection of gene modules of "Escherichia coli" indicates that all the algorithms suffer of instability and variability issues with regards to the reconstruction of the topology of the network. This instability makes objectively very hard the task of establishing which method performs best. Nevertheless, RegnANN shows MCC scores that compare very favorably with all the other inference methods tested. Availability: The software for the RegnANN inference algorithm is distributed under GPL3 and it is available at the corresponding author home page (http://mpba.fbk.eu/grimaldi/regnann-supmat
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