o-Positronium scattering off H and He

Exploiting an approach similar to the R-matrix theory, the diffusion Monte Carlo method is employed to compute phase shifts and threshold cross sections for the elastic scattering of o-positronium off light atoms. Results are obtained for Ps-H and Ps-He as representative cases of open and closed shell targets. The method allows for an exact treatment of both correlation and exchange interactions, and represents the most promising approach to deal with these effects in more complicated targets. In particular the Ps-He threshold cross section, computed in a many body framework for the first time, represents a standard by which past and future numerical and experimental estimates can be judged.Comment: 5 pages, 3 figures, submitted to Phys. Rev. Let

Intra-Domain Pathlet Routing

Internal routing inside an ISP network is the foundation for lots of services that generate revenue from the ISP's customers. A fine-grained control of paths taken by network traffic once it enters the ISP's network is therefore a crucial means to achieve a top-quality offer and, equally important, to enforce SLAs. Many widespread network technologies and approaches (most notably, MPLS) offer limited (e.g., with RSVP-TE), tricky (e.g., with OSPF metrics), or no control on internal routing paths. On the other hand, recent advances in the research community are a good starting point to address this shortcoming, but miss elements that would enable their applicability in an ISP's network. We extend pathlet routing by introducing a new control plane for internal routing that has the following qualities: it is designed to operate in the internal network of an ISP; it enables fine-grained management of network paths with suitable configuration primitives; it is scalable because routing changes are only propagated to the network portion that is affected by the changes; it supports independent configuration of specific network portions without the need to know the configuration of the whole network; it is robust thanks to the adoption of multipath routing; it supports the enforcement of QoS levels; it is independent of the specific data plane used in the ISP's network; it can be incrementally deployed and it can nicely coexist with other control planes. Besides formally introducing the algorithms and messages of our control plane, we propose an experimental validation in the simulation framework OMNeT++ that we use to assess the effectiveness and scalability of our approach.Comment: 13 figures, 1 tabl

Mediterranean diet and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is emerging as the most common chronic liver disease, and is characterized by a wide spectrum of fat-liver disorders that can result in severe liver disease and cirrhosis. Inflammation and oxidative stress are the major risk factors involved in the pathogenesis of NAFLD. Currently, there is no consensus concerning the pharmacological treatment of NAFLD. However, lifestyle interventions based on exercise and a balanced diet for quality and quantity, are considered the cornerstone of NAFLD management. Mediterranean diet (MD), rich in polyunsaturated fats, polyphenols, vitamins and carotenoids, with their anti-inflammatory and antioxidant effects, has been suggested to be effective in preventing cardiovascular risk factors. In adults, MD has also been demonstrated to be efficacious in reducing the risk of metabolic syndrome. However, few studies are available on the effects of the MD in both adult and pediatric subjects with NAFLD. Thus, the aims of the present narrative review are to analyze the current clinical evidence on the impact of MD in patients with NAFLD, and to summarize the main mechanisms of action of MD components on this condition

Annihilation rate in positronic systems by quantum Monte Carlo: e(+)LiH as test case

An accurate method to compute the annihilation rate in positronic systems by means of quantum Monte Carlo simulations is tested and compared with previously proposed methods using simple model systems. This method can be applied within all the quantum Monte Carlo techniques, just requiring the accumulation of the positron-electron distribution function. The annihilation rate of e(+)LiH as a function of the internuclear distance is studied using a model potential approach to eliminate the core electrons of Li, and explicitly correlated wave functions to deal with all the remaining particles. These results allow us to compute vibrationally averaged annihilation rates, and to understand the effect of the Li+ electric field on positron and electron distributions. (C) 2002 American Institute of Physics

Evaluating The Potential Energy Savings Of An Urban Green Infrastructure Through Environmental Simulation

Green infrastructure is a very important aspect to be considered in designing and preparing cities to adapt and mitigate climate change impacts on the built environment. Green based solutions have a strong impact on many aspects, such as controlling storm-water, reducing urban heat island effect, stabilizing soils, facing earthquakes, etcetera. In this paper an environmental analysis is performed by simulation with TRNSYS Studio tool. The cooling potential that can be obtained by trees in residential compounds is assessed, considering shadowing effect, changes in air movement, sky view factor reduction and other simulation-parameter changes. Results show that a reduction of 30 to 50% in cooling demand can be obtained by using a raw of trees on South, East and especially West façades. Two types of trees are tested, showing different cooling performances depending on the height and form of the trees

Assessing climate change and urban heat island vulnerabilities in a built environment

A methodology is presented to assess local criticalities and resilience to climate changes (CC) and UHI (Urban Heat Island). This analysis will consider the expected impacts on the local energy demand of the built environment due to climate-related variations. Climate-related indicators are proposed to assess a vulnerability index to CC and UHI in specific building-design contexts. Furthermore, these indicators will be applied to a set of locations in the Mediterranean climate while taking into consideration different local contexts to evaluate the resilience of a sample residential building by using, among other strategies, dynamic energy simulations

Cardiometabolic risk factors in children with celiac disease on a gluten-free diet

Celiac disease (CD) is an immune-mediated systemic condition evoked by gluten and related prolamines in genetically predisposed subjects. It is characterised by a variable combination of gluten-dependent clinical symptoms, CD-specific antibodies, HLA-DQ2 and HLA-DQ8 haplotypes, and enteropathy. The only therapy of CD consists of a life-long gluten free diet (GFD). Strict GFD adherence results in full clinical, serological and histological remission, avoiding long-term complications in CD patients. However, this diet is not without problems. Gluten free products have high levels of lipids, sugar and salt to improve food palatability and consistency, and subjects with CD show an excessive consumption of hypercaloric and hyperlipidic foods to compensate dietetic restriction. GFD may therefore have a negative impact on cardiometabolic risk factors such as obesity, serum lipid levels, insulin resistance, metabolic syndrome, and atherosclerosis. In adults, some studies have suggested that GFD have a beneficial effect on cardiovascular profile, whereas others have shown an atherogenic effect of GFD. In children, very few studies are available on the issue. Thus, the aim of the present narrative review was to analyze the current clinical evidence on the impact of GFD on cardiometabolic risk factors in children with CD

Aorto-iliac aneurysm associated with congenital pelvic kidney: A short series of successful open repairs under hypothermic selective renal perfusion

The occurrence of congenital pelvic kidney (cPK) during aorto-iliac aneurysm repair is an extremely unusual finding. We report a series of four patients with aorto-iliac aneurysm and associated cPK who underwent aorto-iliac repair at our institution over the last 10 years. Aorto-iliac aneurysm repair under cPK selective hypothermic perfusion was successfully accomplished in all cases. All the cPK arteries were spared and were selectively reimplanted when required. No major complications or death were reported at long-term follow-up. Open surgical repair of aorto-iliac aneurysm in patients with cPK is safe and effective and, in our short series, we observed no worsening of the renal function; besides, we reported a persistent improvement of the renal function in two out of the four cases

Fatty acid profile, Desaturase and Atherogenic indices in milk of Holstein Friesian and Italian autochthonous cattle breeds

In the past decades, milk has been considered a mere supplier of nutrients, although its importance was considered paramount for the development and growth of newborns, a number of aspects regarding the biological functions of milk are still unknown. Several positive functional properties of milk derive from fatty acids (FA), mainly unsaturated fatty acids (UFA), either monounsaturated (MUFA) or polyunsaturated (PUFA) fatty acids. In particular, UFAs are considered functional components of food because of their positive effects on disease prevention (FAO, 2010; Connor W.E. ,2000;  Wijendran V., 2004). The objective of this study was to characterize the fatty acid profile, the desaturase index and the atherogenic index in milk of local Italian bovine breeds (Cabannina, Varzese and Valdostana) and in a cosmopolitan breed (Holstein Friesian) during the first period of lactation. A total number of 129 cows have been enrolled (Friesian n=30, Cabannina n=30, Varzese n=30, Valdostana n=39) from three dairy farms with similar management and feeding conditions. Animals were chosen in order to have three classes of lactation stage: milk collections were carried out starting from 40±10 days (group A), 70±10 days (group B), and 130±10 days (group C). Milk samples have been analyzed by gas chromatography to obtain the fatty acid profile, on the basis of these results, the Desaturase and Atherogenic Indices were calculated. A   number   of   differences   between   breeds have been  found, in   particular local  breeds showed an higher  percentages  of  UFA,  MUFA,  PUFA,  and  a  higher  UFA/SFA  ratio, as well as lower desaturase indices (related to C14, C16 and C18) and atherogenic index, when compared to Friesian cows. The results can add further information aiming to re-evaluate an almost lost local treasure in Northern Italy.