6,819 research outputs found

    Sex Differences Independent of Other Psycho-sociodemographic Factors as a Predictor of Body Mass Index in Black South African Adults

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    To better understand the sex differences in body mass index (BMI) observed in black South African adults in the Transition and Health during Urbanization of South Africans Study, the present study investigated whether these differences can be explained by the psycho-sociodemographic factors and/or health-related behaviours. A cross-sectional survey was undertaken among 1,842 black South African individuals from 37 study sites that represented five levels of urbanization. The behavioural factors that possibly could have an influence on the outcome of body-weight and that were explored included: diet, smoking, level of education, HIV infection, employment status, level of urbanization, intake of alcohol, physical activity, and neuroticism. The biological factors explored were age and sex. The prevalence of underweight, normal weight, and overweight among men and women was separately determined. The means of the variables were compared by performing Student's t-test for normally-distributed variables and Mann-Whitney U-test for non-normally-distributed variables. The means for the underweight and overweight groups were tested for significant differences upon comparison with normal-weight individuals stratified separately for sex. The differences in prevalence were tested using chi-square tests (p<0.05). All the variables with a large number of missing values were tested for potential bias. The association between sex and underweight or overweight was tested using the Mantel-Haenszel method of odds ratio (OR) and calculation of 95% confidence interval (CI), with statistical significance set at p<0.05 level. Logistic regression was used for controlling for confounders and for testing for effect modification. Females were more likely to be overweight/obese (crude OR=5.1; CI 3.8-6.8). The association was attenuated but remained strong and significant even after controlling for the psycho-sociodemographic confounders. In this survey, the risk for overweight/obesity was strongly related to sex and not to the psycho-sociodemographic external factors investigated. It is, thus, important to understand the molecular roots of sex and gender-specific variability in distribution of BMI as this is central to the future development of treatment and prevention programmes against overweight/obesity

    Adjustments in end-effector trajectory and underlying joint angle synergies after a target switch:Order of adjustment is flexible

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    Goal-directed reaching adapts to meet changing task requirements after unexpected perturbations such as a sudden switch of target location. Literature on adaptive behavior using a target switch has primarily focused on adjustments of the end-effector trajectory, addressing proposed feedback and feedforward processes in planning adjusted actions. Starting from a dynamical systems approach to motor coordination, the current paper focusses on coordination of joint angles after a target switch, which has received little attention in the literature. We argue that joint angles are coordinated in synergies, temporary task-specific units emerging from interactions amongst task, organism, and environmental constraints. We asked whether after a target switch: i) joint angles were coordinated in synergies, ii) joint angles were coordinated in a different synergy than the synergy used when moving to the original target, and iii) synergies or end-effector trajectory was adjusted first. Participants (N = 12) performed manual reaching movements toward a target on a table (stationary target trials), where in some trials the target could unexpectedly switch to a new location (switch trials). Results showed that the end-effector curved to the switched target. Joint angles were synergistically organized as shown by the large extent of co-variation based on Uncontrolled Manifold analyses. At the end of the target switch movement, joint angle configurations differed from the joint angle configurations used to move to the original stationary target. Hence, we argue, a new synergy emerged after the target switch. The order of adjustment in the synergies and in the end-effector was flexible within participants, though most often synergies were adjusted first. These findings support the two-step framework of Kay (1988) to understand the coordination of abundant degrees of freedom and to explain adaptive actions. The flexibility in the order of adjustments of synergies suggests that the coordination of DOF emerges from self-organization

    Lifetime and production rate of NOx in the upper stratosphere and lower mesosphere in the polar spring/summer after the solar proton event in October–November 2003

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    We present altitude-dependent lifetimes of NOx, determined with MIPAS/ENVISAT (the Michelson Interferometer for Passive Atmospheric Sounding/the European Environment Satellite), for the Southern polar region after the solar proton event in October-November 2003. Between 50° S and 90° S and decreasing in altitude they range from about two days at 64 km to about 20 days at 44 km. The lifetimes are controlled by transport, mixing and photochemistry. We infer estimates of dynamical lifetimes by comparison of the observed decay to photochemical lifetimes calculated with the SLIMCAT 3-D Model. Photochemical loss contributes to the observed NOx depletion by 0.1% at 44 km, increasing with altitude to 45% at 64 km. In addition, we show the correlation of modelled ionization rates and observed NOx densities under consideration of the determined lifetimes of NOx, and calculate altitude-dependent effective production rates of NOx due to ionization. For that we compare ionization rates of the AIMOS data base with the MIPAS measurements from 15 October-31 December 2003. We derive effective NOx-production rates to be applied to the AIMOS ionization rates which range from about 0.2 NOx-molecules per ion pair at 44 km to 0.7 NOx-molecules per ion pair at 62 km. These effective production rates are considerably lower than predicted by box model simulations which could hint at an overestimation of the modelled ionization rates. © Author(s) 2013.F. Friederich, H. Nieder, and M. Sinnhuber gratefully acknowledge funding by the Helmholtz society, grant VH-NG-624.Peer Reviewe

    Purification and Characterization of Diacylglycerol Pyrophosphate Phosphatase from Saccharomyces cerevisiae

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    Diacylglycerol pyrophosphate (DGPP) phosphatase is a novel membrane-associated enzyme that catalyzes the dephosphorylation of the β phosphate of DGPP to yield phosphatidate and P. DGPP phosphatase was purified 33,333-fold from Saccharomyces cerevisiae by a procedure that included Triton X-100 solubilization of microsomal membranes followed by chromatography with DE53, Affi-Gel Blue, hydroxylapatite, and Mono Q. The procedure resulted in the isolation of an apparent homogeneous protein with a subunit molecular mass of 34 kDa. DGPP phosphatase activity was associated with the 34-kDa protein. DGPP phosphatase had a broad pH optimum between 6.0 and 8.5 and was dependent on Triton X-100 for maximum activity. The enzyme was inhibited by divalent cations, NaF, and pyrophosphate and was relatively insensitive to thioreactive agents. The turnover number (molecular activity) for the enzyme was 5.8 × 103 min-1 at pH 6.5 and 30°C. DGPP phosphatase exhibited typical saturation kinetics with respect to DGPP (Km = 0.55 mol %). The Km for DGPP was 3-fold greater than its cellular concentration (0.18 mol %). DGPP phosphatase also catalyzed the dephosphorylation of phosphatidate, but this dephosphorylation was subsequent to the dephosphorylation of the β phosphate of DGPP. The dependence of activity on phosphatidate (Km = 2.2 mol %) was cooperative (Hill number = 2.0). DGPP was the preferred substrate for the enzyme with a specificity constant (Vmax /Km) 10-fold greater than that for phosphatidate. In addition, DGPP potently inhibited (Ki = 0.35 mol %) the dephosphorylation of phosphatidate by a competitive mechanism whereas phosphatidate did not inhibit the dephosphorylation of DGPP. DGPP was neither a substrate nor an inhibitor of pure phosphatidate phosphatase from S. cerevisiae. DGPP was synthesized from phosphatidate via the phosphatidate kinase reaction

    Lowering IceCube's energy threshold for point source searches in the Southern Sky

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    Observation of a point source of astrophysical neutrinos would be a "smoking gun" signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current ν μ interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (~100 TeV) starting event in the sample found that this event alone represents a 2.8σ deviation from the hypothesis that the data consists only of atmospheric background.Fil: Aartsen, M. G.. University of Adelaide; AustraliaFil: Abraham, K.. Technische Universität München; AlemaniaFil: Ackermann, M.. Deutsches Elektronen-Synchrotron; AlemaniaFil: Adams, J.. University Of Canterbury; Nueva ZelandaFil: Aguilar, J. A.. Université Libre de Bruxelles; BélgicaFil: Golup, Geraldina Tamara. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Wallace, A.. University of Adelaide; AustraliaFil: Wallraff, M.. Rwth Aachen University; AlemaniaFil: Wandkowsky, N.. University of Wisconsin; Estados UnidosFil: Weaver, Ch.. University of Alberta; CanadáFil: Wendt, C.. University of Wisconsin; Estados UnidosFil: Westerhoff, S.. University of Wisconsin; Estados UnidosFil: Whelan, B. J.. University of Adelaide; AustraliaFil: Whitehorn, N.. University of California at Berkeley; Estados UnidosFil: Wickmann, S.. Rwth Aachen University; AlemaniaFil: Wiebe, K.. Johannes Gutenberg Universitat Mainz; AlemaniaFil: Wiebusch, C. H.. Rwth Aachen University; AlemaniaFil: Wille, L.. University of Wisconsin; Estados UnidosFil: Williams, D. R.. University of Alabama at Birmingahm; Estados UnidosFil: Wills, L.. Drexel University; Estados UnidosFil: Wissing, H.. University of Maryland; Estados UnidosFil: Wolf, M.. Stockholms Universitet; SueciaFil: Wood, T. R.. University of Alberta; CanadáFil: Woschnagg, K.. University of California at Berkeley; Estados UnidosFil: Xu, D. L.. University of Wisconsin; Estados UnidosFil: Xu, X. W.. Southern University; Estados UnidosFil: Xu, Y.. Stony Brook University; Estados UnidosFil: Yanez, J. P.. Deutsches Elektronen-Synchrotron; AlemaniaFil: Yodh, G.. University of California at Irvine; Estados UnidosFil: Yoshida, S.. Chiba University; JapónFil: Zoll, M.. Stockholms Universitet; Sueci

    Lifetime and production rate of NOx in the upper stratosphere and lower mesosphere in the polar spring/summer after the solar proton event in October - November 2003

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    We present altitude-dependent lifetimes of NOx, determined with MIPAS/ENVISAT (the Michelson Interferometer for Passive Atmospheric Sounding/the European Environment Satellite), for the Southern polar region after the solar proton event in October–November 2003. Between 50° S and 90° S and decreasing in altitude they range from about two days at 64 km to about 20 days at 44 km. The lifetimes are controlled by transport, mixing and photochemistry. We infer estimates of dynamical lifetimes by comparison of the observed decay to photochemical lifetimes calculated with the SLIMCAT 3-D Model. Photochemical loss contributes to the observed NOx depletion by 0.1% at 44 km, increasing with altitude to 45% at 64 km. In addition, we show the correlation of modelled ionization rates and observed NOx densities under consideration of the determined lifetimes of NOx, and calculate altitudedependent effective production rates of NOx due to ionization. For that we compare ionization rates of the AIMOS data base with the MIPAS measurements from 15 October–31 December 2003. We derive effective NOx-production rates to be applied to the AIMOS ionization rates which range from about 0.2 NOx-molecules per ion pair at 44 km to 0.7 NOx-molecules per ion pair at 62 km. These effective production rates are considerably lower than predicted by box model simulations which could hint at an overestimation of the modelled ionization rates

    Soluble triggering receptor on myeloid cells-1 is expressed in the course of non-infectious inflammation after traumatic lung contusion: a prospective cohort study

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    Introduction: The triggering receptor expressed on myeloid cells-1 (TREM-1) is known to be expressed during bacterial infections. We investigated whether TREM-1 is also expressed in non-infectious inflammation following traumatic lung contusion. Methods: In a study population of 45 adult patients with multiple trauma and lung contusion, we obtained bronchoalveolar lavage (BAL) (blind suctioning of 20 ml NaCl (0.9%) via jet catheter) and collected blood samples at two time points (16 hours and 40 hours) after trauma. Post hoc patients were assigned to one of four groups radiologically classified according to the severity of lung contusion based on the initial chest tomography. Concentration of soluble TREM-1 (sTREM-1) and bacterial growth were determined in the BAL. sTREM-1, IL-6, IL-10, lipopolysaccharide binding protein, procalcitonin, C-reactive protein and leukocyte count were assessed in blood samples. Pulmonary function was evaluated by the paO2/FiO2 ratio. Results: Three patients were excluded due to positive bacterial growth in the initial BAL. In 42 patients the severity of lung contusion correlated with the levels of sTREM-1 16 hours and 40 hours after trauma. sTREM-1 levels were significantly (P < 0.01) elevated in patients with severe contusion (2,184 pg/ml (620 to 4,000 pg/ml)) in comparison with patients with mild (339 pg/ml (135 to 731 pg/ml)) or no (217 pg/ml (97 to 701 pg/ml)) contusion 40 hours following trauma. At both time points the paO2/FiO2 ratio correlated negatively with sTREM-1 levels (Spearman correlation coefficient = -0.446, P < 0.01). Conclusions: sTREM-1 levels are elevated in the BAL of patients following pulmonary contusion. Furthermore, the levels of sTREM-1 in the BAL correlate well with both the severity of radiological pulmonary tissue damage and functional impairment of gas exchange (paO2/FiO2 ratio)

    Rashba-type spin splitting at Au(111) beyond the Fermi level: the other part of the story

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    We present a combined experimental and theoretical study of spin–orbit-induced spin splittings in the unoccupied surface electronic structure of the prototypical Rashba system Au(111). Spin- and angle-resolved inverse-photoemission measurements reveal a Rashba-type spin splitting in the unoccupied part of the L-gap surface state. With increasing momentum parallel to the surface, the spectral intensity is lowered and the spin splitting vanishes as the surface state approaches the band-gap boundary. Furthermore, we observe significantly spin-dependent peak positions and intensities for transitions between unoccupied sp-like bulk bands. Possible reasons for this behavior are considered: initial and final-state effects as well as the transition itself, which is controlled by selection rules depending on the symmetry of the involved states. Based on model calculations, we identify the initial states as origin of the observed Rashba-type spin effects in bulk transitions
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