4,253 research outputs found

    Nuclear Astrophysics in Rare Isotope Facilities

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    Nuclear reactions in stars are difficult to measure directly in the laboratory at the small astrophysical energies. In recent years indirect methods with rare isotopes have been developed and applied to extract low-energy astrophysical cross sections.Comment: Invited talk (parallel section) at the Int. Conf. Nucleus-Nucleus Collisions (NN2009), Beijing, China, August 16-21, 2009. To appear in Nucl. Phys.

    Body mass index, waist circumference, and chronic disease risk factors in australian adolescents

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    Objective: To determine the association between measures of adiposity (body mass index and waist circumference) and risk factors for heart disease, type 2 diabetes, fatty liver disease, and the clustering of risk factors in middle adolescence. Design: Cross-sectional study. Setting: Secondary schools in Sydney. Participants: Grade 10 students (N = 496; 58.4% boys; mean [SD] age, 15.4 [0.4] years). Main Exposures: Height, weight, waist circumference, blood pressure, and fasting blood samples. Outcome Measures: Participants were categorized as overweight or obese using the International Obesity Task Force cut points and the UK waist circumference cut points. Blood was analyzed for high- and low-density lipoprotein cholesterol, triglycerides, insulin, glucose, alanine aminotransferase, γ-glutamyltransferase, and high-sensitivity C-reactive protein levels, and the results were categorized as normal or abnormal according to published guidelines where possible. Associations between overweight and obesity and risk factors were explored using logistic regression. Clustering of risk factors within individuals was also explored. Results: Insulin (P < .001), alanine aminotransferase (P < .001), γ-glutamyltransferase (P = .005), high-density lipoprotein cholesterol (P < .001), highsensitivity C-reactive protein (P < .001), and blood pressure (P < .001) were significantly associated with overweight and obesity in adolescent boys. In adolescent girls, insulin, high-density lipoprotein cholesterol (P < .001), and high-sensitivity C-reactive protein (P < .001) were significantly associated with overweight and obesity. Obese adolescent boys and girls were significantly more likely to have 2 or more risk factors (boys: 73.5% vs 7.6%; girls: 44.4% vs 5.4%; P < .001 for both) than nonoverweight adolescents. Conclusions: Overweight and obese adolescents, especially boys, are at substantial risk for chronic conditions. Waist circumference is not a better predictor of metabolic risk factors than is body mass index. ©2008 American Medical Association. All rights reserved

    A carbonate-banded iron formation transition in the Early Protorezoicum of South Africa

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    Seven new and two resurveyed stratigraphic sections through the important carbonate-BIF transition in Griqualand West are presented and compared with six published sections. Lateral correlation within this zone is attempted but the variability was found to be too great for meaningful subdivision. Substantial lithological irregularity is the only unifying character of this zone, for which the new name Finsch Member (Formation) is proposed. Vertical and lateral lithological variations as well as chemical changes across this zone are discussed with reference to environmental aspects. Local and regional considerations lead to the conclusion that fresh water-sea water mixing occurred in a shallowing basin

    Indirect techniques in nuclear astrophysics. Asymptotic Normalization Coefficient and Trojan Horse

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    Owing to the presence of the Coulomb barrier at astrophysically relevant kinetic energies it is very difficult, or sometimes impossible, to measure astrophysical reaction rates in the laboratory. That is why different indirect techniques are being used along with direct measurements. Here we address two important indirect techniques, the asymptotic normalization coefficient (ANC) and the Trojan Horse (TH) methods. We discuss the application of the ANC technique for calculation of the astrophysical processes in the presence of subthreshold bound states, in particular, two different mechanisms are discussed: direct capture to the subthreshold state and capture to the low-lying bound states through the subthreshold state, which plays the role of the subthreshold resonance. The ANC technique can also be used to determine the interference sign of the resonant and nonresonant (direct) terms of the reaction amplitude. The TH method is unique indirect technique allowing one to measure astrophysical rearrangement reactions down to astrophysically relevant energies. We explain why there is no Coulomb barrier in the sub-process amplitudes extracted from the TH reaction. The expressions for the TH amplitude for direct and resonant cases are presented.Comment: Invited talk on the Conference "Nuclear Physics in Astrophysics II", Debrecen, Hungary, 16-20 May, 200

    Outcomes and costs of primary care surveillance and intervention for overweight or obese children: the LEAP 2 randomised controlled trial

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    addresses: Royal Children's Hospital, Murdoch Childrens Research Institute and University of Melbourne, Parkville, Vic 3052, Australia. [email protected]: PMCID: PMC2737607types: Journal Article; Multicenter Study; Randomized Controlled Trial; Research Support, Non-U.S. Gov'tCopyright © 2009 by the BMJ Publishing Group Ltd. This articles was first published in: BMJ, 2009, Vol. 339, pp. b3308 -To determine whether ascertainment of childhood obesity by surveillance followed by structured secondary prevention in primary care improved outcomes in overweight or mildly obese children

    Colored Resonant Signals at the LHC: Largest Rate and Simplest Topology

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    We study the colored resonance production at the LHC in a most general approach. We classify the possible colored resonances based on group theory decomposition, and construct their effective interactions with light partons. The production cross section from annihilation of valence quarks or gluons may be on the order of 400 - 1000 pb at LHC energies for a mass of 1 TeV with nominal couplings, leading to the largest production rates for new physics at the TeV scale, and simplest event topology with dijet final states. We apply the new dijet data from the LHC experiments to put bounds on various possible colored resonant states. The current bounds range from 0.9 to 2.7 TeV. The formulation is readily applicable for future searches including other decay modes.Comment: 29 pages, 9 figures. References updated and additional K-factors include

    MRI in multiple myeloma : a pictorial review of diagnostic and post-treatment findings

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    Magnetic resonance imaging (MRI) is increasingly being used in the diagnostic work-up of patients with multiple myeloma. Since 2014, MRI findings are included in the new diagnostic criteria proposed by the International Myeloma Working Group. Patients with smouldering myeloma presenting with more than one unequivocal focal lesion in the bone marrow on MRI are considered having symptomatic myeloma requiring treatment, regardless of the presence of lytic bone lesions. However, bone marrow evaluation with MRI offers more than only morphological information regarding the detection of focal lesions in patients with MM. The overall performance of MRI is enhanced by applying dynamic contrast-enhanced MRI and diffusion weighted imaging sequences, providing additional functional information on bone marrow vascularization and cellularity. This pictorial review provides an overview of the most important imaging findings in patients with monoclonal gammopathy of undetermined significance, smouldering myeloma and multiple myeloma, by performing a 'total' MRI investigation with implications for the diagnosis, staging and response assessment. Main message aEuro cent Conventional MRI diagnoses multiple myeloma by assessing the infiltration pattern. aEuro cent Dynamic contrast-enhanced MRI diagnoses multiple myeloma by assessing vascularization and perfusion. aEuro cent Diffusion weighted imaging evaluates bone marrow composition and cellularity in multiple myeloma. aEuro cent Combined morphological and functional MRI provides optimal bone marrow assessment for staging. aEuro cent Combined morphological and functional MRI is of considerable value in treatment follow-up

    Dijet signals of the Little Higgs model with T-parity

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    The Littest Higgs model with T-parity (LHT), apart from offering a viable solution to the naturalness problem of the Standard Model, also predicts a set of new fermions as well as a candidate for dark matter. We explore the possibility of discovering the heavy T-odd quark Q_H at the LHC in a final state comprising two hard jets with a large missing transverse momentum. Also discussed is the role of heavy flavor tagging.Comment: Changes in text. Some references adde

    Potential cost-effectiveness of e-health interventions for treating overweight and obesity in Australian adolescents.

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    BACKGROUND: E-health, defined as the use of information and communication technologies to improve healthcare delivery and health outcomes, has been promoted as a cost-effective strategy to treat adolescent overweight and obesity. However, evidence supporting this claim is lacking. OBJECTIVES: Assess the potential cost-effectiveness of a hypothetical e-health intervention for adolescents with overweight and obesity. METHODS: The costs and effect size (BMI reduction) of the hypothetical intervention were sourced from recent systematic reviews. Using a micro-simulation model with a lifetime time horizon, we conducted a modelled cost-utility analysis of the intervention compared to a 'do-nothing' approach. To explore uncertainty, we conducted bootstrapping on individual-level costs and quality-adjusted life years (QALYs) and performed multiple one-way sensitivity analyses. RESULTS: The incremental cost-effectiveness ratio (ICER) for the e-health intervention was dominant (cheaper and more effective), with a 96% probability of being cost-effective at a willingness-to-pay (WTP) of 50000/QALY.TheICERremaineddominantinallsensitivityanalysesexceptwhenusingthelowerboundsofthehypotheticalinterventioneffectsize,whichreducedtheprobabilityofcosteffectivenessataWTPof50 000/QALY. The ICER remained dominant in all sensitivity analyses except when using the lower bounds of the hypothetical intervention effect size, which reduced the probability of cost-effectiveness at a WTP of 50 000/QALY to 51%. CONCLUSION: E-health interventions for treatment of adolescent overweight and obesity demonstrate very good cost-effectiveness potential and should be considered by healthcare decision makers. However, further research on the efficacy of such interventions is warranted to strengthen the case for investment

    Pharmacological screening using an FXN-EGFP cellular genomic reporter assay for the therapy of Friedreich ataxia

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    Copyright @ 2013 Li et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Friedreich ataxia (FRDA) is an autosomal recessive disorder characterized by neurodegeneration and cardiomyopathy. The presence of a GAA trinucleotide repeat expansion in the first intron of the FXN gene results in the inhibition of gene expression and an insufficiency of the mitochondrial protein frataxin. There is a correlation between expansion length, the amount of residual frataxin and the severity of disease. As the coding sequence is unaltered, pharmacological up-regulation of FXN expression may restore frataxin to therapeutic levels. To facilitate screening of compounds that modulate FXN expression in a physiologically relevant manner, we established a cellular genomic reporter assay consisting of a stable human cell line containing an FXN-EGFP fusion construct, in which the EGFP gene is fused in-frame with the entire normal human FXN gene present on a BAC clone. The cell line was used to establish a fluorometric cellular assay for use in high throughput screening (HTS) procedures. A small chemical library containing FDA-approved compounds and natural extracts was screened and analyzed. Compound hits identified by HTS were further evaluated by flow cytometry in the cellular genomic reporter assay. The effects on FXN mRNA and frataxin protein levels were measured in lymphoblast and fibroblast cell lines derived from individuals with FRDA and in a humanized GAA repeat expansion mouse model of FRDA. Compounds that were established to increase FXN gene expression and frataxin levels included several anti-cancer agents, the iron-chelator deferiprone and the phytoalexin resveratrol.Muscular Dystrophy Association (USA), the National Health and Medical Research Council (Australia), the Friedreich’s Ataxia Research Alliance (USA), the Brockhoff Foundation (Australia), the Friedreich Ataxia Research Association (Australasia), Seek A Miracle (USA) and the Victorian Government’s Operational Infrastructure Support Program
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