1,448 research outputs found
Donor-specific Cell-based Assays in Studying Sensitivity to Low-dose Radiation: A Population-based Perspective
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
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
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
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
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
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PILGRM: an interactive data-driven discovery platform for expert biologists
PILGRM (the platform for interactive learning by genomics results mining) puts advanced supervised analysis techniques applied to enormous gene expression compendia into the hands of bench biologists. This flexible system empowers its users to answer diverse biological questions that are often outside of the scope of common databases in a data-driven manner. This capability allows domain experts to quickly and easily generate hypotheses about biological processes, tissues or diseases of interest. Specifically PILGRM helps biologists generate these hypotheses by analyzing the expression levels of known relevant genes in large compendia of microarray data. Because PILGRM is data-driven, it complements a user’s knowledge and literature analysis with mining of diverse functional genomic data, thereby generating novel predictions that can drive experimental follow-up. This server is free, does not require registration and is available for use at http://pilgrm.princeton.edu
The institutional shaping of management: in the tracks of English individualism
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
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Task-Shifting and Task-Sharing in Neurosurgery: An International Survey of Current Practices in Low- and Middle-Income Countries.
BACKGROUND: Because nearly 23,000 more neurosurgeons are needed globally to address 5 million essential neurosurgical cases that go untreated each year, there is an increasing interest in task-shifting and task-sharing (TS/S), delegating neurosurgical tasks to nonspecialists, particularly in low- and middle-income countries (LMICs). This global survey aimed to provide a cross-sectional understanding of the prevalence and structure of current neurosurgical TS/S practices in LMICs. METHODS: The survey was distributed to a convenience sample of individuals providing neurosurgical care in LMICs with a Web-based survey link via electronic mailing lists of continental societies and various neurosurgical groups, conference announcements, e-mailing lists, and social media platforms. Country-level data were analyzed by descriptive statistics. RESULTS: The survey yielded 127 responses from 47 LMICs; 20 countries (42.6%) reported ongoing TS/S. Most TS/S procedures involved emergency interventions, the top 3 being burr holes, craniotomy for hematoma evacuation, and external ventricular drain. Most (65.0%) believed that their Ministry of Health does not endorse TS/S (24.0% unsure), and only 11% believed that TS/S training was structured. There were few opportunities for TS/S providers to continue medical education (11.6%) or maintenance of certification (9.4%, or receive remuneration (4.2%). CONCLUSIONS: TS/S is ongoing in many LMICs without substantial structure or oversight, which is concerning for patient safety. These data invite future clinical outcomes studies to assess effectiveness and discussions on policy recommendations such as standardized curricula, certification protocols, specialist oversight, and referral networks to increase the level of TS/S care and to continue to increase the specialist workforce
Reverse Engineering Gene Networks with ANN: Variability in Network Inference Algorithms
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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