Baryon stopping in 40 and 158 GeV/nucleon Pb+Pb collisions

Proton rapidity distributions have been measured by the NA49 collaboration in 40 and 158 GeV/nucleon Pb+Pb collisions as function of collision centrality. We find that the shape and the yield per wounded nucleon in the mid-rapidity region vary little with centrality and are similar to the distributions obtained from inelastic p+p interactions. This observation is satisfactorily described by the transport models HSD and UrQMD, although there are significant differences in the details of the spectral shape between the experimental data and the models as well as between the models. The approximate invariance of the normalized proton spectrum in the vicinity of mid-rapidity suggests that multiple nucleon-nucleon interactions in nuclear collisions at SPS energies have little effect on the spectra of those final state protons which are slowed down the most.Comment: CPOD 2009 Proceedings, NA49 Collaboration, 10 page

Effects of Collective Potentials on Pion Spectra in Relativistic Heavy Ion Collisions

The effect of collective potentials on pion spectra in ultrarelativistic heavy ion collisions is investigated. We find the effect of these potential to be very small, too small to explain the observed enhancement at low transverse momenta. (7 figures, bill be send on request)Comment: 11 page

Side Ridge in Ar + KCl Collisions at 1.8 GeV/nucleon with Reaction-Plane Deblurring

Reaction-plane deblurring is applied to the triple-differential distributions of protons, deuterons and negatively charged pions from central Ar + KCl collisions at 1.8 GeV/nucleon, measured with the LBL-GSI Streamer Chamber, to yield distributions relative to the true reaction plane of the collisions. Within the reaction plane and in the forward cm rapidity region a side ridge away from the beam axis is observed: the distributions peak away from the beam direction for protons and deuterons but not for pions. These findings are consistent with a source of particles moving at an in-plane transverse velocity of ~0.1 c. Transport pBUU calculations yield results in semi-quantitative agreement with those from the data.Comment: 5 pages, 3 figure

The RHIC Zero Degree Calorimeter

High Energy collisions of nuclei usually lead to the emission of evaporation neutrons from both ``beam'' and ``target'' nuclei. At the RHIC heavy ion collider with 100GeV/u beam energy, evaporation neutrons diverge by less than $~2$ milliradians from the beam axis Neutral beam fragments can be detected downstream of RHIC ion collisions (and a large aperture Accelerator dipole magnet) if $\theta\leq$ 4 mr but charged fragments in the same angular range are usually too close to the beam trajectory. In this 'zero degree' region produced particles and other secondaries deposit negligible energy when compared with that of beam fragmentation neutrons. The purpose of the RHIC zero degree calorimeters (ZDC's) is to detect neutrons emitted within this cone along both beam directions and measure their total energy (from which we calculate multiplicity). The ZDC coincidence of the 2 beam directions is a minimal bias selection of heavy ion collisions. This makes it useful as an event trigger and a luminosity monitor\cite{baltz} and for this reason we built identical detectors for all 4 RHIC experiments. The neutron multiplicity is also known to be correlated with event geometry \cite{appel} and will be used to measure collision centrality in mutual beam int eractions.Comment: 18 pages, 12 figure

Determinants of Physical Activity and Screen Time Trajectories in 7th to 9th Grade Adolescents-A Longitudinal Study

Physical activity (PA) in youth tends to decline with increasing age, while sedentary behaviour including screen time (ST) increases. There are adolescents, however, whose PA and ST do not follow this pattern. The aim of this study is (i) to examine trajectories in PA and ST from grade 7-9 among students in Berlin, and (ii) to investigate the relationship of these trajectories with individual factors and school type. For the present analyses, changes in students' PA and ST across three time points from 7th to 9th grade were assessed via self-report questionnaires. Positive and negative trajectories were defined for both PA (positive: increasing or consistently high, negative: decreasing or consistently low) and ST (vice versa). Multivariable logistic regression analyses were performed to identify possible predictors of PA and ST trajectories. In total, 2122 students were included (50.2% girls, mean age 12.5 (standard deviation 0.7) years). Compared to grade 7, less students of grade 9 fulfilled PA and ST recommendations (PA: 9.4% vs. 13.2%; ST: 19.4% vs. 25.0%). The positive PA trajectory included 44% of all students (63% boys), while the positive ST trajectory included 21% of all students (30% boys). Being a boy was significantly associated with a positive PA trajectory, while being a girl, having a high socioeconomic status, and attending a high school, were significantly associated with a positive ST trajectory. Different PA and ST trajectories among adolescents should be taken into account when implementing prevention programs for this target group

An explorative cross-sectional study examining self-reported health and nutritional status of disadvantaged people using food banks in Germany

Background Even in high-income countries some population groups depend on food banks to support their food intake. We aimed to explore and compare health and nutritional status of food bank clients (Tafel e.V.) in different cities in Germany. Methods In a cross-sectional study, self-reported health and nutritional status of food bank clients living in three cities (Berlin - capital, Ludwigsburg- affluent city, Fulda - small town) which differ in size, available income and poverty rate, were assessed and compared to survey variables of the low socioeconomic status population of national surveys (DEGS and GEDA). Results Across cities, food bank clients (N = 276, response rate of 21.5 %) did not differ in main socio-demographic characteristics (age, nationality, education, professional qualification, household income). Smoking, having at least one chronic illness, estimating their own health status as moderate to poor and low consumption of fruits and vegetables were common characteristics. Comparing selected variables with the low socioeconomic status population of DEGS and GEDA, differences were found for a higher prevalence of diabetes among food bank clients and a worse self- reported health status. Considerably lower fruit consumption and lower hypertension prevalence among female and lower overweight rates among male food bank clients were found. Conclusions Although people using food banks vary in socio-demographic background, no differences for main demographics across the cities were found. In addition, the study suggests that for some health- and nutrition-related variables, national surveys in Germany might underestimate socioeconomic differences

Assessing the variety and pricing of selected foods in socioeconomically disparate districts of Berlin, Germany

Aim: The neighbourhood environment appears to influence people’s food consumption. Access, variety and pricing of foods play a role in the socioeconomic difference of fruit and vegetable consumption. This study compared differences in the number of grocery stores, variety of fresh fruits and vegetables, and food prices in districts with different Social Indices (SI) in Berlin, Germany. Methods: The district with the lowest SIs was compared to the district with the highest SI. The number of grocery stores offering fresh produce, the variety of fresh fruits and vegetables, and prices of selected healthy and less healthy food items were assessed and compared. Results: The low SI district had more grocery stores per residents than the high SI district. Variety and prices of fruits and vegetables did not differ between the two districts, but milk and whole wheat bread were less expensive in the high SI district. For all grocery stores, selected foods with higher energy density had lower energy costs than low energy density foods. Conclusion: Health inequalities in Germany might be less influenced by access to healthy foods than in other countries, but nutrient-rich foods such as fruits and vegetables have higher energy costs than high energy dense foods

Pion-pair formation and the pion dispersion relation in a hot pion gas

The possibility of pion--pair formation in a hot pion gas, based on the bosonic gap equation, is pointed out and discussed in detail. The critical temperature for condensation of pion pairs (Evans--Rashid transition) is determined as a function of the pion density. As for fermions, this phase transition is signaled by the appearance of a pole in the two--particle propagator. In bose systems there exists a second, lower critical temperature, associated with the appearance of the single--particle condensate. Between the two critical temperatures the pion dispersion relation changes from the usual quasiparticle dispersion to a Bogoliubov--like dispersion relation at low momenta. This generalizes the non-relativistic result for an attractive bose gas by Evans et al. Possible consequences for the inclusive pion spectra measured in heavy--ion collisions at ultra--relativistic energies are discussed.Comment: 16 pages revtex, 7 Postscript figure

On-sky results of the adaptive optics MACAO for the new IR-spectrograph CRIRES at VLT

The adaptive optics MACAO has been implemented in 6 focii of the VLT observatory, in three different flavors. We present in this paper the results obtained during the commissioning of the last of these units, MACAO-CRIRES. CRIRES is a high-resolution spectrograph, which efficiency will be improved by a factor two at least for point-sources observations with a NGS brighter than R=15. During the commissioning, Strehl exceeding 60% have been observed with fair seeing conditions, and a general description of the performance of this curvature adaptive optics system is done.Comment: SPIE conference 2006, Advances in adaptive optics, 12 pages, 11 figure