968 research outputs found

    Exotic and excited-state radiative transitions in charmonium from lattice QCD

    Full text link
    We compute, for the first time using lattice QCD methods, radiative transition rates involving excited charmonium states, states of high spin and exotics. Utilizing a large basis of interpolating fields we are able to project out various excited state contributions to three-point correlators computed on quenched anisotropic lattices. In the first lattice QCD calculation of the exotic 1-+ eta_c1 radiative decay, we find a large partial width Gamma(eta_c1 -> J/psi gamma) ~ 100 keV. We find clear signals for electric dipole and magnetic quadrupole transition form factors in chi_c2 -> J/psi gamma, calculated for the first time in this framework, and study transitions involving excited psi and chi_c1,2 states. We calculate hindered magnetic dipole transition widths without the sensitivity to assumptions made in model studies and find statistically significant signals, including a non-exotic vector hybrid candidate Y_hyb? -> eta_c gamma. As well as comparison to experimental data, we discuss in some detail the phenomenology suggested by our results and the extent to which it mirrors that of quark potential models and make suggestions for the interpretation of our results involving exotic quantum numbered states

    Early infant feeding and adiposity risk: from infancy to adulthood

    Get PDF
    Introduction: Systematic reviews suggest that a longer duration of breast-feeding is associated with a reduction in the risk of later overweight and obesity. Most studies examining breast-feeding in relation to adiposity have not used longitudinal analysis. In our study, we aimed to examine early infant feeding and adiposity risk in a longitudinal cohort from birth to young adulthood using new as well as published data. Methods: Data from the Western Australian Pregnancy Cohort (Raine) Study in Perth, W.A., Australia, were used to examine associations between breast-feeding and measures of adiposity at 1, 2, 3, 6, 8, 10, 14, 17, and 20 years. Results: Breast-feeding was measured in a number of ways. Longer breast-feeding (in months) was associated with reductions in weight z-scores between birth and 1 year (β = -0.027; p \u3c 0.001) in the adjusted analysis. At 3 years, breast-feeding for \u3c4 months increased the odds of infants experiencing early rapid growth (OR 2.05; 95% CI 1.43-2.94; p \u3c 0.001). From 1 to 8 years, children breast-fed for ≤4 months compared to ≥12 months had a significantly greater probability of exceeding the 95th percentile of weight. The age at which breast-feeding was stopped and a milk other than breast milk was introduced (introduction of formula milk) played a significant role in the trajectory of the BMI from birth to 14 years; the 4-month cutoff point was consistently associated with a higher BMI trajectory. Introduction of a milk other than breast milk before 6 months compared to at 6 months or later was a risk factor for being overweight or obese at 20 years of age (OR 1.47; 95% CI 1.12-1.93; p = 0.005). Discussion: Breast-feeding until 6 months of age and beyond should be encouraged and is recommended for protection against increased adiposity in childhood, adolescence, and young adulthood. Adverse long-term effects of early growth acceleration are fundamental in later overweight and obesity. Formula feeding stimulates a higher postnatal growth velocity, whereas breast-feeding promotes slower growth and a reduced likelihood of overweight and obesity. Biological mechanisms underlying the protective effect of breast-feeding against obesity are based on the unique composition and metabolic and physiological responses to human milk

    Relationship between dietary intake and erythrocyte PUFA in adolescents from a Western Australian cohort

    Get PDF
    Background: Population-based studies show that the intake of omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFA) are associated with a range of health conditions. Therefore, the reliability of food frequency questionnaires (FFQ) as rapid and easily accessible screening tools for PUFA intake deserve investigation. Objective: We aimed to assess the relationship between erythrocyte fatty acids and fatty acid intake collected using the Commonwealth Scientific and Industrial Research Organisation (CSIRO) food frequency questionnaire in an adolescent cohort. Design: A cross-sectional study using data from 1155 young adolescents participating in the 14-year follow-up of the Raine Study. Bland–Altman plots were used to determine the agreement between dietary intake and erythrocyte levels of each fatty acid. Results: The main dietary source of n-3 long-chain (LC) PUFA was ‘fresh fish’ (53% of total n-3 LC-PUFA). Docosahexaenoic acid (DHA) showed the strongest correlation between erythrocyte and diet assessment (r = 0.274; p \u3c 0.001), whilst linoleic acid (LA) (r = 0.103; p \u3c 0.001) and arachidonic acid (AA) (r = − 0.06; p = 0.042) showed weaker correlations, with limits of agreement relatively narrow. Bland–Altman plots showed a dose-dependent bias between the FFQ fatty acid data and corresponding erythrocyte data. Conclusions: For the major n-3 and n-6 PUFA, dietary intakes derived from the FFQ showed weaker correlations and poorer agreement with erythrocyte levels, and the deviation between the two increased with higher intake levels

    Changes in dairy food and nutrient intakes in Australian adolescents

    Get PDF
    Dairy nutrients, such as calcium, are particularly important in adolescence, a critical time for growth and development. There are limited Australian data following individuals through adolescence, evaluating changes in dairy nutrient and dairy product consumption. We used a validated food frequency questionnaire to investigate consumption in adolescents participating in both the 14 and 17 year follow-ups of the Western Australian Pregnancy Cohort (Raine) Study. Most adolescents did not reach age and gender specific recommended daily intakes for calcium or magnesium at 14 years, and this decreased as they aged to 17 years (from 33.0% to 29.2% meeting for calcium, P \u3c 0.05, and from 33.6% to 20.5% meeting for magnesium, P \u3c 0.01). Mean intakes of calcium, potassium, riboflavin and vitamin A also decreased with age (P \u3c 0.01). Mean dairy intake decreased from 536 ± 343 g/day to 464 ± 339 g/day (P \u3c 0.01), due mostly to a decrease in regular milk, although flavoured milk consumption increased in boys. Cheese and butter were the only products to show a significantly increased consumption over the period. Girls decreased from 2.2 to 1.9 serves/day of dairy, while boys remained relatively steady at 2.9 to 2.8 serves/day. Our findings suggest that dairy product consumption decreases over adolescence. This may have implications for bone mass, development and later health

    Fetal growth trajectories and measures of insulin resistance in young adults

    Get PDF
    Context: Events during gestation greatly influence the risk of cardiometabolic diseases including diabetes in offspring during later life. Objective: This study aimed to investigate relationships between serial ultrasound-derived fetal growth trajectories and markers of insulin resistance in young adults in the Raine Study, an Australian pregnancy cohort. Methods: Linear mixed modeling examined the relationship between fetal growth trajectory groups, constructed using serial ultrasound-based abdominal circumference (AC), femur length (FL), and head circumference (HC) from 1333 mother-fetal pairs, and offspring Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), as a marker of diabetes risk, at 20 (n = 414), 22 (n = 385), and 27 (n = 431) years. Analyses were adjusted for age, sex, ethnicity, socioeconomic status, adult lifestyle factors, and maternal factors during pregnancy. Results: The study identified 7 AC, 5 FL, and 5 HC growth trajectory groups. Compared to the average-stable (reference) group, a low-falling AC growth trajectory (26%; P = .005) and 2 low HC growth trajectories (20%; P = .006% and 8%; P = .021) were associated with higher adult HOMA-IR. Trajectories representing a high-stable FL and a rising HC were associated with 12% (P = .002) and 9% (P = .021) lower adult HOMA-IR, respectively, compared to the reference group. Conclusion: Restricted fetal HC and AC from early pregnancy are associated with higher relative insulin resistance in the offspring during adulthood. These data strengthen our understanding of the importance of the intrauterine environment and its effect on the risk of predisposition to adult diabetes and related metabolic disorders

    Sex differences in the association of phospholipids with components of the metabolic syndrome in young adults

    Get PDF
    BACKGROUND: There are differences in the prevalence and severity of diseases between males, females not taking hormonal contraceptives (non-HC females) and females taking hormonal contraceptives (HC females). The aim of this study was to identify sex-specific differences in the metabolome and its relation to components of the metabolic syndrome in a young adult population. METHODS: The subjects analysed are from the 20-year follow-up of the Western Australian Pregnancy Cohort (Raine) Study. Two hundred fifteen plasma metabolites were analysed in 1021 fasted plasma samples by a targeted liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) metabolomics approach. Principal component analysis between males (n = 550), non-HC females (n = 199) and HC females (n = 269) was applied. Regression analysis with a sex x metabolite concentration interaction was performed on components of the MetS, namely waist circumference, systolic blood pressure, and plasma HDL-C, triglycerides and glucose concentration, as outcome to select the significant metabolites of the interaction. Those selected metabolites were used as predictors in a sex group stratified analysis to compare the different beta coefficients and therefore the sex group-dependent associations. RESULTS: Principal component analysis between males, non-HC females, and HC females showed a general discriminating trend between males and HC females. One hundred twenty-seven metabolites were significantly different between males and non-HC females, whereas 97 differed between non-HC females and HC females. Males and non-HC females mainly differed in sphingomyelin, lyso-phosphatidylcholine, acyl-carnitine and amino acid species, whilst non-HC females and HC females mainly differed in phosphatidylcholine, lyso-phosphatidylcholine and acyl-carnitine concentrations. Forty-one metabolites (phosphatidylcholines, sphingomyelines, lyso-phosphatidylcholine) were significantly differently associated with the MetS factors in the different groups. CONCLUSIONS: We have shown clear differences between plasma metabolite concentrations in males, and HC or non-HC females, especially in lyso-phosphatidylcholine, sphingomyelin and phosphatidylcholine, which have been shown to associate with obesity in other studies. The association of these metabolites differed between sexes with components of the metabolic syndrome, which means that development of diseases like obesity and diabetes may differ between the sexes. Our findings highlight the importance of considering sex differences when conducting a metabolomics study and the need to account for the effect of HC usage in females in future studies

    Comparing the effects of sun exposure and vitamin D supplementation on vitamin D insufficiency, and immune and cardio-metabolic function: the Sun Exposure and Vitamin D Supplementation (SEDS) Study

    Get PDF
    BACKGROUND Adults living in the sunny Australian climate are at high risk of skin cancer, but vitamin D deficiency (defined here as a serum 25-hydroxyvitamin D (25(OH)D) concentration of less than 50 nmol/L) is also common. Vitamin D deficiency may be a risk factor for a range of diseases. However, the optimal strategies to achieve and maintain vitamin D adequacy (sun exposure, vitamin D supplementation or both), and whether sun exposure itself has benefits over and above initiating synthesis of vitamin D, remain unclear. The Sun Exposure and Vitamin D Supplementation (SEDS) Study aims to compare the effectiveness of sun exposure and vitamin D supplementation for the management of vitamin D insufficiency, and to test whether these management strategies differentially affect markers of immune and cardio-metabolic function. METHODS/DESIGN The SEDS Study is a multi-centre, randomised controlled trial of two different daily doses of vitamin D supplementation, and placebo, in conjunction with guidance on two different patterns of sun exposure. Participants recruited from across Australia are aged 18-64 years and have a recent vitamin D test result showing a serum 25(OH)D level of 40-60 nmol/L. DISCUSSION This paper discusses the rationale behind the study design, and considers the challenges but necessity of data collection within a non-institutionalised adult population, in order to address the study aims. We also discuss the challenges of participant recruitment and retention, ongoing engagement of referring medical practitioners and address issues of compliance and participant retention. TRIAL REGISTRATION Australia New Zealand Clinical Trials Registry: ACTRN12613000290796 Registered 14 March 2013

    Instability and `Sausage-String' Appearance in Blood Vessels during High Blood Pressure

    Get PDF
    A new Rayleigh-type instability is proposed to explain the `sausage-string' pattern of alternating constrictions and dilatations formed in blood vessels under influence of a vasoconstricting agent. Our theory involves the nonlinear elasticity characteristics of the vessel wall, and provides predictions for the conditions under which the cylindrical form of a blood vessel becomes unstable.Comment: 4 pages, 4 figures submitted to Physical Review Letter
    • …
    corecore