163 research outputs found

    Association Between Overweight or Obesity and Household Income and Parental Body Mass Index in Australian Youth: Analysis of the Australian National Nutrition Survey, 1995

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    This study is a secondary data analysis based on the 1995 Australian National Nutrition Survey (NNS). A random subsample of 1581 school children aged 7 15 years old from the NNS was studied. The results show the prevalence of overweight, obesity and combined overweight and obesity was 10.6 20.9%, 3.7 7.2% and 15.6 25.7%, respectively. The odds ratio of overweight or obese boys with highest household income was significantly smaller than those with the lowest household income. The proportion of combined overweight and obesity in children whose parents were overweight or obese was significantly greater compared with those whose parents were not. The trend of increasing prevalence of overweight or obesity among children with increasing parental body mass index (BMI) was significant after adjusting for age except the trend of father's BMI for boys. This study provided baseline data on the recent prevalence of overweight or obesity of Australian school children using new international absolute BMI cut-off points. It indicated that young school girls (7 9 years) were more likely to be overweight or obese compared with boys, the prevalence rates of overweight or obesity in older boys (13 15 year) was significantly greater than in other age groups while in girls it was the opposite. The boys with lowest household income (017500)weremorelikelytobeoverweightorobesecomparedwiththosewiththehighesthouseholdincome(greaterthan0 17 500) were more likely to be overweight or obese compared with those with the highest household income (greater than 67 500). Having parents especially mothers who were overweight or obese may increase the risk of children being overweight or obese

    Yersinia enterocolitica palearctica serobiotype O:3/4 - a successful group of emerging zoonotic pathogens

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    <p>Abstract</p> <p>Background</p> <p>High-pathogenic <it>Y. enterocolitica </it>ssp. <it>enterocolitica </it>caused several human outbreaks in Northern America. In contrast, low pathogenic <it>Y. enterocolitica </it>ssp. <it>palearctica </it>serobiotype O:3/4 is responsible for sporadic cases worldwide with asymptomatic pigs being the main source of infection. Genomes of three <it>Y. enterocolitica </it>ssp. <it>palearctica </it>serobiotype O:3/4 human isolates (including the completely sequenced Y11 German DSMZ type strain) were compared to the high-pathogenic <it>Y. enterocolitica </it>ssp. <it>enterocolitica </it>8081 O:8/1B to address the peculiarities of the O:3/4 group.</p> <p>Results</p> <p>Most high-pathogenicity-associated determinants of <it>Y. enterocolitica </it>ssp. <it>enterocolitica </it>(like the High-Pathogenicity Island, <it>yts1 </it>type 2 and <it>ysa </it>type 3 secretion systems) are absent in <it>Y. enterocolitica </it>ssp. <it>palearctica </it>serobiotype O:3/4 genomes. On the other hand they possess alternative putative virulence and fitness factors, such as a different <it>ysp </it>type 3 secretion system, an RtxA-like and insecticidal toxins, and a N-acetyl-galactosamine (GalNAc) PTS system (<it>aga</it>-operon). Horizontal acquisition of two prophages and a tRNA-Asn-associated GIYep-01 genomic island might also influence the <it>Y. enterocolitica </it>ssp. <it>palearctica </it>serobiotype O:3/4 pathoadaptation. We demonstrated recombination activity of the PhiYep-3 prophage and the GIYep-01 island and the ability of the <it>aga</it>-operon to support the growth of the <it>Y. enterocolitica </it>ssp. <it>enterocolitica </it>O:8/1B on GalNAc.</p> <p>Conclusions</p> <p><it>Y. enterocolitica </it>ssp. <it>palearctica </it>serobiotype O:3/4 experienced a shift to an alternative patchwork of virulence and fitness determinants that might play a significant role in its host pathoadaptation and successful worldwide dissemination.</p

    A Requirement of TolC and MDR Efflux Pumps for Acid Adaptation and GadAB Induction in Escherichia coli

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    BACKGROUND: The TolC outer membrane channel is a key component of several multidrug resistance (MDR) efflux pumps driven by H(+) transport in Escherichia coli. While tolC expression is under the regulation of the EvgA-Gad acid resistance regulon, the role of TolC in growth at low pH and extreme-acid survival is unknown. METHODS AND PRINCIPAL FINDINGS: TolC was required for extreme-acid survival (pH 2) of strain W3110 grown aerobically to stationary phase. A tolC deletion decreased extreme-acid survival (acid resistance) of aerated pH 7.0-grown cells by 10(5)-fold and of pH 5.5-grown cells by 10-fold. The requirement was specific for acid resistance since a tolC defect had no effect on aerobic survival in extreme base (pH 10). TolC was required for expression of glutamate decarboxylase (GadA, GadB), a key component of glutamate-dependent acid resistance (Gad). TolC was also required for maximal exponential growth of E. coli K-12 W3110, in LBK medium buffered at pH 4.5-6.0, but not at pH 6.5-8.5. The TolC growth requirement in moderate acid was independent of Gad. TolC-associated pump components EmrB and MdtB contributed to survival in extreme acid (pH 2), but were not required for growth at pH 5. A mutant lacking the known TolC-associated efflux pumps (acrB, acrD, emrB, emrY, macB, mdtC, mdtF, acrEF) showed no growth defect at acidic pH and a relatively small decrease in extreme-acid survival when pre-grown at pH 5.5. CONCLUSIONS: TolC and proton-driven MDR efflux pump components EmrB and MdtB contribute to E. coli survival in extreme acid and TolC is required for maximal growth rates below pH 6.5. The TolC enhancement of extreme-acid survival includes Gad induction, but TolC-dependent growth rates below pH 6.5 do not involve Gad. That MDR resistance can enhance growth and survival in acid is an important consideration for enteric organisms passing through the acidic stomach

    Survey of A_LT' asymmetries in semi-exclusive electron scattering on He4 and C12

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    Single spin azimuthal asymmetries A_LT' were measured at Jefferson Lab using 2.2 and 4.4 GeV longitudinally polarized electrons incident on He4 and C12 targets in the CLAS detector. A_LT' is related to the imaginary part of the longitudinal-transverse interference and in quasifree nucleon knockout it provides an unambiguous signature for final state interactions (FSI). Experimental values of A_LT' were found to be below 5%, typically |A_LT'| < 3% for data with good statistical precision. Optical Model in Eikonal Approximation (OMEA) and Relativistic Multiple-Scattering Glauber Approximation (RMSGA) calculations are shown to be consistent with the measured asymmetries.Comment: 9 pages, 5 figure

    Onset of asymptotic scaling in deuteron photodisintegration

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    We investigate the transition from the nucleon-meson to quark-gluon description of the strong interaction using the photon energy dependence of the d(γ,p)nd(\gamma,p)n differential cross section for photon energies above 0.5 GeV and center-of-mass proton angles between 3030^{\circ} and 150150^{\circ}. A possible signature for this transition is the onset of cross section s11s^{-11} scaling with the total energy squared, ss, at some proton transverse momentum, PTP_T. The results show that the scaling has been reached for proton transverse momentum above about 1.1 GeV/c. This may indicate that the quark-gluon regime is reached above this momentum.Comment: Accepted by PRL; 5 pages, 2 figure

    Single pi+ Electroproduction on the Proton in the First and Second Resonance Regions at 0.25GeV^2 < Q^2 < 0.65GeV^2 Using CLAS

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    The ep -> e'pi^+n reaction was studied in the first and second nucleon resonance regions in the 0.25 GeV^2 < Q^2 < 0.65 GeV^2 range using the CLAS detector at Thomas Jefferson National Accelerator Facility. For the first time the absolute cross sections were measured covering nearly the full angular range in the hadronic center-of-mass frame. The structure functions sigma_TL, sigma_TT and the linear combination sigma_T+epsilon*sigma_L were extracted by fitting the phi-dependence of the measured cross sections, and were compared to the MAID and Sato-Lee models.Comment: Accepted for publication in PR

    Photodisintegration of 4^4He into p+t

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    The two-body photodisintegration of 4^4He into a proton and a triton has been studied using the CEBAF Large-Acceptance Spectrometer (CLAS) at Jefferson Laboratory. Real photons produced with the Hall-B bremsstrahlung-tagging system in the energy range from 0.35 to 1.55 GeV were incident on a liquid 4^4He target. This is the first measurement of the photodisintegration of 4^4He above 0.4 GeV. The differential cross sections for the γ\gamma4^4Hept\to pt reaction have been measured as a function of photon-beam energy and proton-scattering angle, and are compared with the latest model calculations by J.-M. Laget. At 0.6-1.2 GeV, our data are in good agreement only with the calculations that include three-body mechanisms, thus confirming their importance. These results reinforce the conclusion of our previous study of the three-body breakup of 3^3He that demonstrated the great importance of three-body mechanisms in the energy region 0.5-0.8 GeV .Comment: 13 pages submitted in one tgz file containing 2 tex file and 22 postscrip figure

    π0\pi^0 photoproduction on the proton for photon energies from 0.675 to 2.875 GeV

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    Differential cross sections for the reaction γppπ0\gamma p \to p \pi^0 have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged photon beam with energies from 0.675 to 2.875 GeV. The results reported here possess greater accuracy in the absolute normalization than previous measurements. They disagree with recent CB-ELSA measurements for the process at forward scattering angles. Agreement with the SAID and MAID fits is found below 1 GeV. The present set of cross sections has been incorporated into the SAID database, and exploratory fits have been extended to 3 GeV. Resonance couplings have been extracted and compared to previous determinations.Comment: 18 pages, 48 figure

    Exclusive ρ0\rho^0 electroproduction on the proton at CLAS

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    The epepρ0e p\to e^\prime p \rho^0 reaction has been measured, using the 5.754 GeV electron beam of Jefferson Lab and the CLAS detector. This represents the largest ever set of data for this reaction in the valence region. Integrated and differential cross sections are presented. The WW, Q2Q^2 and tt dependences of the cross section are compared to theoretical calculations based on tt-channel meson-exchange Regge theory on the one hand and on quark handbag diagrams related to Generalized Parton Distributions (GPDs) on the other hand. The Regge approach can describe at the \approx 30% level most of the features of the present data while the two GPD calculations that are presented in this article which succesfully reproduce the high energy data strongly underestimate the present data. The question is then raised whether this discrepancy originates from an incomplete or inexact way of modelling the GPDs or the associated hard scattering amplitude or whether the GPD formalism is simply inapplicable in this region due to higher-twists contributions, incalculable at present.Comment: 29 pages, 29 figure

    Exclusive Photoproduction of the Cascade (Xi) Hyperons

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    We report on the first measurement of exclusive Xi-(1321) hyperon photoproduction in gamma p --> K+ K+ Xi- for 3.2 < E(gamma) < 3.9 GeV. The final state is identified by the missing mass in p(gamma,K+ K+)X measured with the CLAS detector at Jefferson Laboratory. We have detected a significant number of the ground-state Xi-(1321)1/2+, and have estimated the total cross section for its production. We have also observed the first excited state Xi-(1530)3/2+. Photoproduction provides a copious source of Xi's. We discuss the possibilities of a search for the recently proposed Xi5-- and Xi5+ pentaquarks.Comment: submitted to Phys. Rev.
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