730 research outputs found

    Iodine source apportionment in the Malawian diet

    Get PDF
    The aim of this study was to characterise nutritional-I status in Malawi. Dietary-I intakes were assessed using new datasets of crop, fish, salt and water-I concentrations, while I status was assessed for 60 women living on each of calcareous and non-calcareous soils as defined by urinary iodine concentration (UIC). Iodine concentration in staple foods was low, with median concentrations of 0.01 mg kg−1 in maize grain, 0.008 mg kg−1 in roots and tubers, but 0.155 mg kg−1 in leafy vegetables. Freshwater fish is a good source of dietary-I with a median concentration of 0.51 mg kg−1. Mean Malawian dietary-Iodine intake from food, excluding salt, was just 7.8 ÎŒg d−1 compared to an adult requirement of 150 ÎŒg d−1. Despite low dietary-I intake from food, median UICs were 203 ÎŒg L−1 with only 12% defined as I deficient whilst 21% exhibited excessive I intake. Iodised salt is likely to be the main source of dietary I intake in Malawi; thus, I nutrition mainly depends on the usage and concentration of I in iodised salt. Drinking water could be a significant source of I in some areas, providing up to 108 ÎŒg d−1 based on consumption of 2 L d−1

    The pi -> pi pi process in nuclei and the restoration of chiral symmetry

    Full text link
    The results of an extensive campaign of measurements of the pi -> pi pi process in the nucleon and nuclei at intermediate energies are presented. The measurements were motivated by the study of strong pi pi correlations in nuclei. The analysis relies on the composite ratio C_{pi pi}^A, which accounts for the clear effect of the nuclear medium on the (pi pi) system. The comparison of the C_{pi pi}^A distributions for the (pi pi)_{I=J=0} and (pi pi)_{I=0,J=2} systems to the model predictions indicates that the C_{pi pi}^A behavior in proximity of the 2m_pi threshold is explainable through the partial restoration of chiral symmetry in nuclei.Comment: accepted for publication in Nucl. Phys.

    RAFT aqueous emulsion polymerization of methyl methacrylate : observation of unexpected constraints when employing a non-ionic steric stabilizer block

    Get PDF
    The RAFT aqueous emulsion polymerization of methyl methacrylate (MMA) is conducted at 70 °C using poly(glycerol monomethacrylate) (PGMA) as a steric stabilizer block. This non-ionic precursor has previously proved to be highly effective for the RAFT aqueous emulsion polymerization of various vinyl monomers such as benzyl methacrylate (BzMA), 2,2,2-trifluoroethyl methacrylate (TFEMA), isopropylideneglycerol monomethacrylate (IPGMA) or glycidyl methacrylate. However, an unexpected constraint was encountered in the case of MMA. Targeting a degree of polymerization (DP) of 20 to 100 for the PMMA block led to colloidal dispersions of kinetically-trapped spherical nanoparticles ranging in size from 17 nm to 31 nm. On the other hand, targeting DPs above 100 invariably led to the formation of highly flocculated spherical nanoparticles. This rather limited DP range is in striking contrast to the much higher DPs that can be targeted without loss of colloidal stability when using more hydrophobic monomers such as BzMA, TFEMA or IPGMA. The same flocculation problem was also evident when employing a PGMA precursor containing an anionic carboxylate end-group, but a series of colloidally stable dispersions could be obtained when using an anionic poly(methacrylic acid) stabilizer. Finally, the efficient removal of RAFT end-groups from PGMA50-PMMA80 nanoparticles was achieved by visible light irradiation using a blue LED source (λ = 405 nm). UV GPC studies confirmed that up to 87% dithiobenzoate end-groups can be removed from such nanoparticles within 12 h at 80 °C. On the other hand, using excess H2O2 under the same conditions only led to 24% end-group removal. This is because this water-soluble reagent has restricted access to the hydrophobic PMMA cores

    General properties of the pion production reaction in nuclear matter

    Full text link
    The pion production reaction π+→π+π±\pi^+ \to \pi^+\pi^{\pm} on 45Sc^{45}Sc was studied at incident pion energies of Tπ+T_{\pi^{+}} = 240, 260, 280, 300, and 320 MeV. The experiment was performed using the M11M11 pion-channel at TRIUMF, and multiparticle events, (π+,π+π±\pi^+,\pi^+\pi^{\pm}) and (π+,π+π±p\pi^+,\pi^+\pi^{\pm}p), were detected with the CHAOS spectrometer. Results are reported in the form of both differential and total cross sections, and are compared to theoretical predictions and the reaction phase space. The present investigation of the T-dependence of the π+A→π+π±Aâ€Č\pi^+ A \to \pi^+\pi^{\pm} A' reaction complements earlier examinations of the A-dependence of the reaction, which was measured using 2H^{2}H, 4He^{4}He, 12C^{12}C, 16O^{16}O, 40Ca^{40}Ca, and 208Pb^{208}Pb targets at ∌\sim280 MeV. Some general properties of the pion-induced pion production reaction in nuclear matter will be presented, based on the combined results of the two studies.Comment: 23 pages, Latex, accepted for publication in Nucl. Phys.

    The ππ\pi\pi interaction in nuclear matter from a study of the π+A→π+π±Aâ€Č\pi^+ A \to \pi^+ \pi^{\pm} A' reactions

    Full text link
    The pion-production reactions π+A→π+π±Aâ€Č\pi^+ A \to \pi^+\pi^{\pm} A' were studied on 2H^{2}H, 12C^{12}C, 40Ca^{40}Ca, and 208Pb^{208}Pb nuclei at an incident pion energy of Tπ+T_{\pi^{+}}=283 MeV. Pions were detected in coincidence using the CHAOS spectrometer. The experimental results are reduced to differential cross sections and compared to both theoretical predictions and the reaction phase space. The composite ratio C\cal CππA_{\pi\pi}^A between the π+π±\pi^{+}\pi^{\pm} invariant masses on nuclei and on the nucleon is also presented. Near the 2mπ2m_{\pi} threshold pion pairs couple to (ππ)I=J=0(\pi\pi)_{I=J=0} when produced in the π+→π+π−\pi^+\to \pi^+\pi^- reaction channel. There is a marked near-threshold enhancement of C\cal Cπ+π−A_{\pi^+\pi^-}^A which is consistent with theoretical predictions addressing the partial restoration of chiral symmetry in nuclear matter. Furthermore, the behaviour of C\cal Cπ+π−A_{\pi^+\pi^-}^A is well described when the restoration of chiral symmetry is combined with standard P-wave renormalization of pions in nuclear matter. On the other hand, nuclear matter only weakly influences C\cal Cπ+π+A_{\pi^+\pi^+}^A, which displays a flat behaviour throughout the energy range regardless of AA.Comment: 30 pages, 16 figures, PS format, accepted for publication in Nucl. Phys

    The cost-effectiveness of sequences of biological disease-modifying antirheumatic drug treatment in England for patients with rheumatoid arthritis who can tolerate methotrexate.

    Get PDF
    Objective: To ascertain whether strategies of treatment with a biological diseasemodifying antirheumatic drug (bDMARD) were cost-effective in an English setting. Results are presented for those patients with moderate-to-severe rheumatoid arthritis (RA) and those with severe RA. Methods: An economic model to assess the cost-effectiveness of seven bDMARDs was developed. A systematic literature review and network meta-analysis was undertaken to establish relative clinical effectiveness. The results together with estimates of: Health Assessment Questionnaire (HAQ) score following European League Against Rheumatism response; annual costs, and utility, per HAQ band; trajectory of HAQ for patients on bDMARDs; and trajectory of HAQ for patients on non-biologic therapy (NBT) were used to populate the model. Results were presented as those associated with the strategy with the median cost-effectiveness. Supplementary analyses were undertaken assessing the change in cost-effectiveness where only patients with the most severe prognoses on NBT were provided with bDMARD treatment. The cost per QALY values were compared with reported thresholds from the National Institute for Health and Care Excellence of ÂŁ20,000 to ÂŁ30,000. Results: In the primary analyses, the cost per QALY of a bDMARD strategy was ÂŁ41,600 for patients with severe RA and ÂŁ51,100 for those with moderate-to-severe RA. Under the supplementary analyses the cost per QALY fell to ÂŁ25,300 for those with severe RA and to ÂŁ28,500 for those with moderate-to-severe RA. Conclusion: The cost-effectiveness of bDMARDs in RA in England is questionable and only meets current accepted levels in subsets of patients with the worst prognoses

    Fertility, Living Arrangements, Care and Mobility

    Get PDF
    There are four main interconnecting themes around which the contributions in this book are based. This introductory chapter aims to establish the broad context for the chapters that follow by discussing each of the themes. It does so by setting these themes within the overarching demographic challenge of the twenty-first century – demographic ageing. Each chapter is introduced in the context of the specific theme to which it primarily relates and there is a summary of the data sets used by the contributors to illustrate the wide range of cross-sectional and longitudinal data analysed

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

    Get PDF
    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

    Get PDF
    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

    Get PDF
    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio
    • 

    corecore