A Fluctuation-Dissipation Process without Time Scale

We study the influence of a dissipation process on diffusion dynamics triggered by fluctuations with long-range correlations. We make the assumption that the perturbation process involved is of the same kind as those recently studied numerically and theoretically, with a good agreement between theory and numerical treatment. As a result of this assumption the equilibrium distribution departs from the ordinary canonical distribution. The distribution tails are truncated, the distribution border is signalled by sharp peaks and, in the weak dissipation limit, the central distribution body becomes identical to a truncated Levy distribution.Comment: REVTeX 3.1, 7 pages, 2 EPS figures, uses epsfig.sty. Submitted to Phys. Rev.

Topography and structural heterogeneities in surface ground deformation: a simulation test for Somma-Vesuvius volcano

Abstract. We simulate the deformation of Somma-Vesuvius volcano due to some overpressure sources by means of a finite element 3D code. The main goal of these simulations is to investigate the influence of topography and structural heterogeneity on ground deformation. In our model the sources of deformation are embedded in an elastic linear isotropic medium and located at various depths. Geometry (shape and lateral extension) of the sources is mainly constrained by the results coming from recent seismic tomography studies. The structural heterogeneity has been modelled in terms of dynamic elastic parameters (Young's modulus) retrieved from previous seismic tomography and gravity studies. A high-resolution digital terrain model is used for the topography of the volcano subaerial edifice. Evidences from our results suggest that real topography and structural heterogeneities are key factors governing the ground deformation, which often turns being one of the most relevant problems in volcano monitoring. A large deviation from the axially symmetrical model of the displacement field is the main result of our modelling. Such an asymmetry is routinely unaccounted for when Mogi's simplistic modelling in a homogeneous medium with simplified topography is used. Our study clearly demonstrate that a better knowledge of deformation patterns can significantly help in the location of monitoring sensors as well as in the design of an efficient geodetic network

Aerodynamic design optimization of wind turbine airfoils under aleatory and epistemic uncertainty

This paper presents different approaches to optimize wind turbine airfoils in an uncertain scenario. The approaches are specifically applied to the aerodynamic design optimization of a wind turbine airfoil accounting for the uncertainty in setting up the XFOIL's NCRIT constant: a parameter that is considered affected by a chain of aleatory and epistemic uncertainty. Subject to a set of aerodynamic and structural constraints, the uncertain response of the airfoil is optimized by means of both probability- and imprecise probability-based approaches. These solutions are compared with a reference airfoil optimized with a conventional design approach, in which the treatment of uncertainty is carried out in a simplistic fashion. Once evaluated in the probabilistic scenario, the airfoil designed with the conventional approach still achieves the largest aerodynamic efficiency mean. This airfoil is however affected by the largest performance sensitivity to NCRIT variations. The airfoils optimized by means of uncertainty-based approaches instead achieve larger performance robustness and reliability than the airfoil optimized with the conventional approach

Are Europeans moving towards dietary habits more suitable for reducing cardiovascular disease risk?

Aims: Cardiovascular diseases are the main cause of death in Europe. Food choices represent the most important factors undermining health and well-being; they account for as much as half of all CVD deaths in Europe. The aim of this viewpoint is to evaluate food choices of the European population and their temporal trends in relation to possible effects on the cardiovascular disease risk. Data synthesis: The CVD death rate attributable to diet-related factors has fallen in Europe over the last 25 years; however, the pace of the reduction has slowed down in the last ten years. In parallel, in the last decade unfavorable changes in the dietary habits associated with CVD risk have occurred. Conclusions: A mismatch exists between the available evidence on the health-promoting potential of the diet and the relatively modest and inconsistent improvements of dietary habits in the European population observed in recent years. Nutritional education alone will not be enough to improve the lifestyle of people in Europe. Policy options to be considered to reach this aim should necessarily include also initiatives for facilitating production, marketing, availability and affordability of healthy foods in each and every European country

Glucose lowering strategies and cardiovascular disease in type 2 diabetes – teachings from the TOSCA.IT study

TOSCA.IT is an institutional, non-industry-supported, head-to-head study comparing long term cardiovascular effects, efficacy and safety of two antidiabetes drugs (pioglitazone vs sulphonylureas) used in combination with metformin in patients with type 2 diabetes mellitus. The study results show that in the absence of clinically evident cardiovascular disease both treatment strategies represent suitable alternatives; however, in consideration of the greater durability of the metabolic effects, the lower risk of hypoglycemia and the potential benefit on atherosclerotic cardiovascular disease, the combination of metformin and pioglitazone may be considered as the preferential therapeutic option. In this review the study is critically evaluated against the background of the evidence accumulated over the last decade on the impact of different glucose lowering drugs on cardiovascular events in people with type 2 diabetes

The Neuquén composite section: magnetostratigraphy and biostratigraphy of the marine lower Jurassic from the Neuquén basin (Argentina)

Paleomagnetic and biostratigraphic data from five marine sedimentary sections in the Argentine Neuquén basin have allowed to construct the Lower Jurassic Neuquén Composite Section. This composite section comprises 14 reversed and 11 normal polarity Zones, in relation to 17 Andean ammonite Assemblage Zones, spanning the Hettangian^Toarcian (Early Jurassic). It represents the first paleomagnetic data of Lower Jurassic marine successions in the Southern Hemisphere. The Neuquén composite Section was correlated to the International Mesozoic Polarity Time Scale which, for the Lower Jurassic, comprises 54 polarity Zones and 16 Standard ammonite Zones. The correlation between the regional and the international biomagnetostratigraphic scales supports but also refines the correlation between the Andean and Standard ammonite zonations. Correlation between the Neuquén composite Section and the polarity sequences recorded in each section helped to assign several unfossiliferous stratigraphical levels to the corresponding biozones.Facultad de Ciencias Naturales y Muse