An Efficient Implementation of Flux Formulae in Multidimensional Relativistic Hydrodynamical Codes

We derive and analyze a simplified formulation of the numerical viscosity terms appearing in the expression of the numerical fluxes associated to several High-Resolution Shock-Capturing schemes. After some algebraic pre-processing, we give explicit expressions for the numerical viscosity terms of two of the most widely used flux formulae, which implementation saves computational time in multidimensional simulations of relativistic flows. Additionally, such treatment explicitely cancells and factorizes a number of terms helping to amortiguate the growing of round-off errors. We have checked the performance of our formulation running a 3D relativistic hydrodynamical code to solve a standard test-bed problem and found that the improvement in efficiency is of high practical interest in numerical simulations of relativistic flows in Astrophysics.Comment: 10 pages, accepted for publication in Computer Physics Communication

Does Helicobacter pylori have a pathogenic role in bronchiectasis?

SummaryAimTo investigate the presence of Helicobacter pylori (H. pylori) in bronchial biopsies of patients with bronchiectasis, by histochemical and immunochemical staining.Setting800-bed tertiary university hospital.MethodsObservational study. Patients: forty-six patients with bronchiectasis in a stable clinical condition and 8 control patients. Interventions: Serum samples determination of IgG levels for H. pylori by ELISA. Inmunostaining with an anti-H. pylori antibody (NCL-HPp, Novocastra) of bronchial mucosa obtained by fiberoptic bronchoscopy from both patients with bronchiectasis and controls.ResultsTwenty-one out of 46 patients with bronchiectasis (46%) had positive serologies for H. pylori. We obtained 40 bronchial biopsies in patients with bronchiectasis and 8 bronchial biopsies in control patients. No evidence of H. pylori was obtained in the bronchial samples of both patients and controls.ConclusionsThe results of our study could not demonstrate the presence of H. pylori in bronchial specimens from patients with bronchiectasis

Ideal cardiovascular health and inflammation in European adolescents: The HELENA study

Background and aims Inflammation plays a key role in atherosclerosis and this process seems to appear in childhood. The ideal cardiovascular health index (ICHI) has been inversely related to atherosclerotic plaque in adults. However, evidence regarding inflammation and ICHI in adolescents is scarce. The aim is to assess the association between ICHI and inflammation in European adolescents. Methods and results As many as 543 adolescents (251 boys and 292 girls) from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional multi-center study including 9 European countries, were measured. C-reactive protein (CRP), complement factors C3 and C4, leptin and white blood cell counts were used to compute an inflammatory score. Multilevel linear models and multilevel logistic regression were used to assess the association between ICHI and inflammation controlling by covariates. Higher ICHI was associated with a lower inflammatory score, as well as with several individual components, both in boys and girls (p < 0.01). In addition, adolescents with at least 4 ideal components of the ICHI had significantly lower inflammatory score and lower levels of the study biomarkers, except CRP. Finally, the multilevel logistic regression showed that for every unit increase in the ICHI, the probability of having an inflammatory profile decreased by 28.1% in girls. Conclusion Results from this study suggest that a better ICHI is associated with a lower inflammatory profile already in adolescence. Improving these health behaviors, and health factors included in the ICHI, could play an important role in CVD prevention