Differential freezeout and pion interferometry at RHIC from covariant transport theory

Puzzling discrepancies between recent pion interferometry data on Au+Au reactions at s^1/2 = 130 and 200 AGeV from RHIC and predictions based on ideal hydrodynamics are analyzed in terms of covariant parton transport theory. The discrepancies of out and longitudinal radii are significantly reduced when the finite opacity of the gluon plasma is taken into account.Comment: 4 pages, 3 EPS figures. Submitted to PR

Dietary energy density in young children across Europe

OBJECTIVES: To describe energy density (ED; kcal g(-1)) of dietary intake of European children. METHODS: From 16 228 children who participated in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) baseline examination, 8551 children with 24-h dietary recalls (24-HDR), with plausible reported energy intakes and complete covariate information were included in the present analysis. ED was calculated using two methods: (1) ED including solid foods (EDF) and (2) ED including solid foods and energy-containing beverages (EDF&B). Beverage energy was calculated in kcal per day. Dietary characteristics and body mass index (BMI) z-score of children aged 2 to 75th percentile. Standardised regression coefficients were estimated to assess the association between dietary characteristics, BMI z-score and ED of the diet. RESULTS: Children with low EDF and EDF&B diets consumed less energy but higher quantity of food and beverages than children with high EDF and EDF&B diets. Consumption of caloric beverages decreased with increasing EDF&B of the diet owing to the relatively low ED of the beverages, in relation to solid foods. Generally, children with low EDF and EDF&B diets showed healthier food choices than peers with higher EDF and EDF&B diets. In this sample, EDF and EDF&B were not associated with BMI z-score. CONCLUSION: Health promotion strategies should proclaim lower ED diets by means of foods with high water and low fat content and mainly fruit and vegetable components. Excluding caloric beverages from EDF calculation is a useful method to avoid misinterpretation of true exposure to a high energy dense diet. We recommend excluding caloric beverages from EDF calculation when investigating the effect of ED on a certain (health) outcome

Elliptic flow at large transverse momenta from quark coalescence

We show that hadronization via quark coalescence enhances hadron elliptic flow at large pT relative to that of partons at the same transverse momentum. Therefore, compared to earlier results based on covariant parton transport theory, more moderate initial parton densities dN/d\eta(b=0) ~ 1500-3000 can explain the differential elliptic flow v_2(pT) data for Au+Au reactions at s^1/2=130 and 200 AGeV from RHIC. In addition, v2(pT) could saturate at about 50% higher values for baryons than for mesons. If strange quarks have weaker flow than light quarks, hadron v_2 at high pT decreases with relative strangeness content.Comment: Minor changes, extended discussion. To appear in PR

Bidirectional associations between psychosocial well-being and body mass index in European children : longitudinal findings from the IDEFICS study

Background: The negative impact of childhood overweight on psychosocial well-being has been demonstrated in a number of studies. There is also evidence that psychosocial well-being may influence future overweight. We examined the bidirectional association between childhood overweight and psychosocial well-being in children from a large European cohort. The dual aim was to investigate the chronology of associations between overweight and psychosocial health indicators and the extent to which these associations may be explained by parental education. Methods: Participants from the IDEFICS study were recruited from eight countries between September 2007 and June 2008 when the children were aged 2 to 9.9 years old. Children and families provided data on lifestyle, psychosocial well-being, and measured anthropometry at baseline and at follow-up 2 years later. This study includes children with weight, height, and psychosocial well-being measurements at both time points (n = 7,831). Psychosocial well-being was measured by the KINDL (R) and Strengths and Difficulties Questionnaire respectively. The first instrument measures health-related quality of life including emotional well-being, self-esteem, parent relations and social relations while the second measures well-being based on emotional symptoms, conduct problems and peer-related problems. Logistic regression was used for modeling longitudinal associations. Results: Children who were overweight at baseline had increased risk of poor health-related quality of life (odds ratio (OR) = 1.23; 95 % confidence interval (CI): 1.03-1.48) measured 2 years later; this association was unidirectional. In contrast to health-related quality of life, poor well-being at baseline was associated with increased risk of overweight (OR = 1.39; 95 % CI: 1.03-1.86) at 2 year follow-up; this association was also only observed in one direction. Adjustment for parental education did not change our findings. Conclusion: Our findings indicate that the association between overweight and psychosocial well-being may be bidirectional but varies by assessment measures. Future research should further investigate which aspects of psychosocial well-being are most likely to precede overweight and which are more likely to be consequences of overweight

Meson and baryon elliptic flow at high pT from parton coalescence

The large and saturating differential elliptic flow v2(pT) observed in Au+Au reactions at RHIC so far could only be explained assuming an order of magnitude denser initial parton system than estimated from perturbative QCD. Hadronization via parton coalescence can resolve this ``opacity puzzle'' because it enhances hadron elliptic flow at large pT relative to that of partons at the same transverse momentum. An experimentally testable consequence of the coalescence scenario is that v2(pT) saturates at about 50% higher values for baryons than for mesons. In addition, if strange quarks have weaker flow than light quarks, hadron v2 at high pT decreases with relative strangeness content.Comment: Talk at SQM2003 [7th Int. Conf. on Strangeness in Quark Matter (Atlantic Beach, NC, USA, Mar 12-17, 2003)] - 6 pages, 5 eps figs, IOP style file

Non-motor Behavioral Alterations of PGC-1 alpha-Deficient Mice - A Peculiar Phenotype With Slight Male Preponderance and No Apparent Progression

Dysfunction of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1 alpha) has been linked to various neurodegenerative and neuropsychiatric disorders; however, reports on psychic behavioral alterations on PGC-1 alpha-deficient animals are sparse. The present study revisited prior observations of anxiety-related, depression-related, and hippocampal memory-related observations having been made on different PGC-1 alpha-deficient murine strains, in a large-scale analysis on whole-body full-length (FL-)PGC-1 alpha-deficient mice. The examinations were performed on animals covering a wide age range enrolled from both sexes, and included paradigms such as the open-field, elevated plus maze, light-dark box, tail suspension test, and spatial recognition two-trial V-maze. The findings revealed no signs of previously reported anxiety-like behavior, but revealed an unexpected phenotype with decreased anxiety behavior consistent throughout different paradigms, with slight male preponderance. This was associated with despair-like anhedonic behavior, consistent with that reported previously, but did not associate with either peripheral or brain alterations in kynurenic acid synthesis, which was previously proposed. Though male FL-PGC-1 alpha-deficient mice tended to perform poorer in the hippocampus-based spatial learning paradigm, the genotype overall was not associated with impairment in spatial memory, contradicting with prior observations. None of the observed alterations deteriorated with age, similarly to motor alterations as reported previously. The most likely contributors of this peculiar phenotype are discussed, with clinicopathological correlations drawn. Being the first to address these behavioral domains within the same PGC-1 alpha-deficient strain, our findings extend the knowledge about the complex in vivo effect of PGC-1 alpha dysfunction and add important notes to research in the field of PGC-1 alpha in connection with neuropsychiatric disorders

Particle correlations at RHIC from parton coalescence dynamics -- first results

A new dynamical approach that combines covariant parton transport theory with hadronization channels via parton coalescence and fragmentation is applied to Au+Au at RHIC. Basic consequences of the simple coalescence formulas, such as elliptic flow scaling and enhanced proton/pion ratio, turn out to be rather sensitive to the spacetime aspects of coalescence dynamics.Comment: Contribution to Quark Matter 2004 (January 11-17, 2004, Oakland, CA). 4 pages, 2 EPS figs, IOP style fil

Reference values for leptin and adiponectin in children below the age of 10 based on the IDEFICS cohort

OBJECTIVE: To establish age- and sex-specific reference values for serum leptin and adiponectin in normal-weight 3.0-8.9-year old European children. SUBJECTS AND METHODS: Blood samples for hormone analysis were taken from 1338 children of the IDEFICS (Identification and prevention of Dietary-and lifestyle-induced health Effects in Children and infantS) study cohort. Only normal-weight children aged 3.0-8.9 years were included (n = 539) in our analysis. Using the General Additive Model for Location Scale and Shape, age-and sex-specific percentiles were derived. The influence of under/overweight and obesity on the proposed reference curves based on normal-weight children was investigated in several sensitivity analyses using the sample without obese children (n = 1015) and the whole study sample (n = 1338). RESULTS: There was a negative age trend of adiponectin blood levels and a positive trend of leptin levels in boys and girls. Percentiles derived for girls were generally higher than those obtained for boys. The corresponding age-specific differences of the 97th percentile ranged from -2.2 to 4.6 mu g ml(-1) and from 2.2 to 4.8 ng ml(-1) for adiponectin and leptin, respectively. CONCLUSIONS: According to our knowledge, these are the first reference values of leptin and adiponectin in prepubertal, normal-weight children. The presented adiponectin and leptin reference curves may allow for a more differentiated interpretation of children's hormone levels in epidemiological and clinical studies

Longitudinal associations of lifestyle factors and weight status with insulin resistance (HOMA-IR) in preadolescent children : the large prospective cohort study IDEFICS

Background: This study investigates prospective associations of anthropometrical and lifestyle indices with insulin resistance (IR) in European children from the IDEFICS cohort. Insulin resistance (IR) is a growing concern in childhood obesity and a central aspect of the metabolic syndrome (MS). It most likely represents the link between obesity and type 2 diabetes. Methods: This longitudinal study included 3348 preadolescent children aged 3 to 10.9 years from 8 European countries who were observed from 2007/2008 to 2009/2010. The main outcome measure in the present analysis is HOMA-IR (homeostasis model assessment as a common proxy indicator to quantify IR) at follow-up and in its longitudinal development. Anthropometrical measures and lifestyle indices, including objectively determined physical activity, were considered, among others factors, as determinants of IR. Prospective associations between IR at follow-up and anthropometrical and lifestyle indices were estimated by logistic regression models. Results: Country-specific prevalence rates of IR in the IDEFICS cohort of European children showed a positive trend with weight category. Prospective multivariate analyses showed the strongest positive associations of IR with BMI z-score (OR = 2.6 for unit change from the mean, 95 % CI 2.1-3.1) and z-score of waist circumference (OR = 2.2 for unit change from the mean, 95 % CI 1.9-2.6), which were analysed in separate models, but also for sex (OR = 2.2 for girls vs. boys, 95 % CI 1.5-3.1 up to OR 2.5, 95 % CI 1.8-3.6 depending on the model), audio-visual media time (OR = 1.2 for an additional hour per day, 95 % CI 1.0-1.4 in both models) and an inverse association of objectively determined physical activity (OR = 0.5 for 3rd compared to 1st quartile, 95 % CI 0.3-0.9 in both models). A longitudinal reduction of HOMA-IR was accompanied with a parallel decline in BMI. Conclusions: This study is, to our knowledge, the first prospective study on IR in a preadolescent children's population. It supports the common hypothesis that overweight and obesity are the main determinants of IR. Our data also indicate that physical inactivity and a sedentary lifestyle are likewise associated with the development of IR, independent of weight status. The promotion of physical activity should thus be considered as an equal option to dietary intervention for the treatment of IR in the paediatric practice