Extraction of the x-dependence of the non-perturbative QCD b-quark fragmentation distribution component

Using recent measurements of the b-quark fragmentation distribution obtained in $e^+e^- \to b \bar{b}$ events registered at the Z pole, the non-perturbative QCD component of the distribution has been extracted independently of any hadronic physics modelling. This distribution depends only on the way the perturbative QCD component has been defined. When the perturbative QCD component is taken from a parton shower Monte-Carlo, the non-perturbative QCD component is rather similar with those obtained from the Lund or Bowler models. When the perturbative QCD component is the result of an analytic NLL computation, the non-perturbative QCD component has to be extended in a non-physical region and thus cannot be described by any hadronic modelling. In the two examples used to characterize these two situations, which are studied at present, it happens that the extracted non-perturbative QCD distribution has the same shape, being simply translated to higher-x values in the second approach, illustrating the ability of the analytic perturbative QCD approach to account for softer gluon radiation than with a parton shower generator.Comment: 13 page

Memory Effect, Rejuvenation and Chaos Effect in the Multi-layer Random Energy Model

We introduce magnetization to the Multi-layer Random Energy Model which has a hierarchical structure, and perform Monte Carlo simulation to observe the behavior of ac-susceptibility. We find that this model is able to reproduce three prominent features of spin glasses, i.e., memory effect, rejuvenation and chaos effect, which were found recently by various experiments on aging phenomena with temperature variations.Comment: 10 pages, 14 figures, to be submitted to J. Phys. Soc. Jp

Highly versatile atomic micro traps generated by multifrequency magnetic field modulation

We propose the realization of custom-designed adiabatic potentials for cold atoms based on multimode radio frequency radiation in combination with static inhomogeneous magnetic fields. For example, the use of radio frequency combs gives rise to periodic potentials acting as gratings for cold atoms. In strong magnetic field gradients the lattice constant can be well below 1 micrometer. By changing the frequencies of the comb in time the gratings can easily be propagated in space, which may prove useful for Bragg scattering atomic matter waves. Furthermore, almost arbitrarily shaped potential are possible such as disordered potentials on a scale of several 100 nm or lattices with a spatially varying lattice constant. The potentials can be made state selective and, in the case of atomic mixtures, also species selective. This opens new perspectives for generating tailored quantum systems based on ultra cold single atoms or degenerate atomic and molecular quantum gases.Comment: 12 pages, 6 figure

The dusty environment of HD 97300 as seen by Herschel and Spitzer

Aims. We analyze the surroundings of HD 97300, one of two intermediate-mass stars in the Chamaeleon I star-forming region. The star is known to be surrounded by a conspicuous ring of polycyclic aromatic hydrocarbons (PAHs). Methods. We present infrared images taken with Herschel and Spitzer using 11 different broad-band filters between 3.6 um and 500 um. We compare the morphology of the emission using cuts along different position angles. We construct spectral energy distributions, which we compare to different dust models, and calculate dust temperatures. We also derive opacity maps and analyze the density structure of the environment of HD 97300. Results. We find that HD 97300 has no infrared excess at or below 24 um, confirming its zero-age main-sequence nature. The morphology of the ring is very similar between 3.6 um and 24 um. The emission at these wavelengths is dominated by either PAH features or PAH continuum. At longer wavelengths, only the northwestern part of the ring is visible. A fit to the 100-500 um observations suggests that the emission is due to relatively warm (~26 K) dust. The temperature gradually decreases with increasing distance from the ring. We find a general decrease in the density from north to south, and an approximate 10% density increase in the northeastern part of the ring. Conclusions. Our results are consistent with the theory that the ring around HD 97300 is essentially a bubble blown into the surrounding interstellar matter and heated by the star.Comment: 6 pages, 3 figures, accepted for publication in A&

Numerical Study of Aging in the Generalized Random Energy Model

Magnetizations are introduced to the Generalized Random Energy Model (GREM) and numerical simulations on ac susceptibility is made for direct comparison with experiments in glassy materials. Prominent dynamical natures of spin glasses, {\it i.e.}, {\em memory} effect and {\em reinitialization}, are reproduced well in the GREM. The existence of many layers causing continuous transitions is very important for the two natures. Results of experiments in other glassy materials such as polymers, supercooled glycerol and orientational glasses, which are contrast to those in spin glasses, are interpreted well by the Single-layer Random Energy Model.Comment: 8 pages, 9 figures, to be submitted to J. Phys. Soc. Jp

One size does not fit all: local determinants of measles vaccination in four districts of Pakistan

Common factors are associated with vaccination. However, despite common factors the pattern of variables related to measles vaccination differs between and within districts. In this study children were more likely to receive measles vaccination if their mother had any formal education, if she knew at least one vaccine preventable disease, and if she had not heard of any bad effects of vaccination. In rural areas, living within 5 km of a vaccination facility or in a community visited by a vaccination team were factors associated with vaccination, as was the mother receiving information about vaccinations

Evolution of predator dispersal in relation to spatio-temporal prey dynamics : how not to get stuck in the wrong place!

Peer reviewedPublisher PD

A Randomized Double-Blind Crossover Study of Phase-Shift Sound Therapy for Tinnitus

Objective. The purpose of this study was to compare the efficacy of the treatment of tinnitus with a phase-shifting pure tone to that of the same tone treatment without phase shifting. Study Design. A double-blind crossover randomized controlled trial. Setting. This study was conducted at the University Medical Center Groningen. Subjects and Methods. Twenty-two patients with predominantly tonal tinnitus underwent both intervention and control treatments. Each treatment consisted of three 30-minute sessions in 1 week. The control treatment was identical to the intervention treatment, except that the stimulus was a pure tone without phase shifting. Questionnaires, tinnitus loudness match, and annoyance and loudness ratings were used to measure treatment effects. Results. Pure-tone treatment and phase-shift treatment had no significant effect on tinnitus according to questionnaires (Tinnitus Handicap Index, Tinnitus Reaction Questionnaire, Hospital Anxiety and Depression Scale, and Maastricht Questionnaire), audiological matching procedures, and loudness and annoyance ratings of tinnitus. Furthermore, phase-shift treatment showed no additional significant improvement in comparison with pure-tone treatment. Changes in questionnaire scores due to pure-tone and the phase-shift treatment were correlated. Conclusion. On average across the group, both treatments failed to demonstrate a significant effect. Both treatments were beneficial for some patients. However, a positive effect was not demonstrated that could be attributed to the periodic shifting of the phase of the stimulus tone

Clinical Use and Effectiveness of Lipid Lowering Therapies in Diabetes Mellitus—An Observational Study from the Swedish National Diabetes Register

OBJECTIVES: To describe the use and evaluate the effectiveness of different lipid lowering therapies in unselected patients with type 1 and type 2 diabetes in clinical practice. DESIGN: Observational population-based study using the personal identification number to link information from the National Diabetes Register, the Prescribed Drug Register and the Patient register in Sweden. All patients in the NDR aged 18-75 years with diabetes more than one year were eligible, but only patients starting any lipid lowering treatment with at least three prescriptions 1 July 2006-30 June 2007 were included (n = 37,182). The mean blood lipid levels in 2008 and reductions in LDL cholesterol were examined. RESULTS: Blood lipid levels were similar in patients treated with simvastatin, atorvastatin and rosuvastatin, showing similar lipid lowering effect as currently used. Users of pravastatin, fluvastatin, ezetimib and fibrate more seldom reach treatment goals. Moderate daily doses of the statins were used, with 76% of simvastatin users taking 20 mg or less, 48% of atorvastatin users taking 10 mg, 55% of pravastatin users taking 20 mg, and 76% of rosuvastatin users taking 5 or 10 mg. CONCLUSIONS: This observational study shows that the LDL-C levels in patients taking simvastatin, atorvastatin or rosuvastatin are very similar as currently used, as well as their LDL-C lowering abilities. There is potential to intensify lipid lowering treatment to reduce the remaining high residual risk and achieve better fulfilment of treatment goals, since the commonly used doses are only low to moderate