1,718 research outputs found

    Evaluation and comparison of satellite precipitation estimates with reference to a local area in the Mediterranean Sea

    Get PDF
    Precipitation is one of the major variables for many applications and disciplines related to water resources and the geophysical Earth system. Satellite retrieval systems, rain-gauge networks, and radar systems are complementary to each other in terms of their coverage and capability of monitoring precipitation. Satellite-rainfall estimate systems produce data with global coverage that can provide information in areas for which data from other sources are unavailable. Without referring to ground measurements, satellite-based estimates can be biased and, although some gauge-adjusted satellite-precipitation products have been already developed, an effective way of integrating multi-sources of precipitation information is still a challenge.In this study, a specific area, the Sicilia Island (Italy), has been selected for the evaluation of satellite-precipitation products based on rain-gauge data. This island is located in the Mediterranean Sea, with a particular climatology and morphology, which can be considered an interesting test site for satellite-precipitation products in the European mid-latitude area. Four satellite products (CMORPH, PERSIANN, PERSIANN-CCS, and TMPA-RT) and two GPCP-adjusted products (TMPA and PERSIANN Adjusted) have been selected. Evaluation and comparison of selected products is performed with reference to data provided by the rain-gauge network of the Island Sicilia and by using statistical and graphical tools. Particular attention is paid to bias issues shown both by only-satellite and adjusted products. In order to investigate the current and potential possibilities of improving estimates by means of adjustment procedures using GPCC ground precipitation, the data have been retrieved separately and compared directly with the reference rain-gauge network data set of the study area.Results show that bias is still considerable for all satellite products, then some considerations about larger area climatology, PMW-retrieval algorithms, and GPCC data are discussed to address this issue, along with the spatial and seasonal characterization of results. © 2013 Elsevier B.V

    Machine-learning blends of geomorphic descriptors: value and limitations for flood hazard assessment across large floodplains

    Get PDF
    Recent literature shows several examples of simplified approaches that perform flood hazard (FH) assessment and mapping across large geographical areas on the basis of fast-computing geomorphic descriptors. These approaches may consider a single index (univariate) or use a set of indices simultaneously (multivariate). What is the potential and accuracy of multivariate approaches relative to univariate ones? Can we effectively use these methods for extrapolation purposes, i.e., FH assessment outside the region used for setting up the model? Our study addresses these open problems by considering two separate issues: (1) mapping flood-prone areas and (2) predicting the expected water depth for a given inundation scenario. We blend seven geomorphic descriptors through decision tree models trained on target FH maps, referring to a large study area (∼ 105 km2). We discuss the potential of multivariate approaches relative to the performance of a selected univariate model and on the basis of multiple extrapolation experiments, where models are tested outside their training region. Our results show that multivariate approaches may (a) significantly enhance flood-prone area delineation (accuracy: 92%) relative to univariate ones (accuracy: 84%), (b) provide accurate predictions of expected inundation depths (determination coefficient ∼0.7), and (c) produce encouraging results in extrapolation

    A single-center experience on below-the-knee endovascular treatment in diabetic patients

    Get PDF
    Diabetic ulceration of the foot is a major global medical, social and economic problem and is the most frequent end-point of diabetic complications. A retrospective analysis from February 2017 to May 2019 of diabetic patients presenting below-the-knee artery disease (PAD) was carried out. Only patients treated with endovascular techniques as first choice treatment were evaluated. Outcome measured was perioperative mortality and morbidity. Freedom from occlusion, secondary patency and amputation rate were all registered. Additional maneuvers including stenting or angioplasty with drug eluting balloon (DEB) were reported. A total of 167 (101 male/66 female) patients with a mean age of 71 years were included in the study. A Rutherford 3, 4, 5 and 6 categories were reported in 5, 7, 110 and 45 patients, respectively. No perioperative mortality was reported. Morbidity occurred in 4 (4.4%) cases and consisted of pseudoaneurysm. Additional stenting during first procedure was required in 7 (4%) patients, drug eluting balloon was needed in 56 (33%) patients. At 1-year follow-up, estimated freedom from occlusion and secondary patency was 70% and 80% respectively. Major amputation rate was 2.4%, minor amputation rate was 41.9%. In our experience, extreme revascularization in search of distal direct flow reduce the rate of amputations with an increase in ulcer healing. New materials and techniques such as drug eluting technology, used properly, can improve outcome

    Synthesis of L-tricholomic acid analogues and pharmacological characterization at ionotropic glutamate receptors

    Get PDF
    The synthesis of analogues of the natural compound ltricholomic acid and of its threo diastereoisomer was accomplished in order to explore their affinity for glutamate ionotropic receptors. In this study, fourteen new unnatural amino acids, characterized by a 3-hydroxy-~2 -isoxazoline or 3- hydroxy-~2 -pyrazoline-skeleton, were obtained exploiting, as key reaction, a 1,3-dipolar cycloaddition or an intramolecular cyclization

    Synthesis of unusual isoxazoline containing β and γ-dipeptides as potential glutamate receptor ligands

    Get PDF
    New unconventional beta and gamma dipeptides, representing conformationally constrained higher homologues of glutamic acid, have been prepared and tested as new pharmacological tools to investigate the iGluR binding domain, in an attempt to identify potential selective antagonists

    Nucleation and Bulk Crystallization in Binary Phase Field Theory

    Full text link
    We present a phase field theory for binary crystal nucleation. In the one-component limit, quantitative agreement is achieved with computer simulations (Lennard-Jones system) and experiments (ice-water system) using model parameters evaluated from the free energy and thickness of the interface. The critical undercoolings predicted for Cu-Ni alloys accord with the measurements, and indicate homogeneous nucleation. The Kolmogorov exponents deduced for dendritic solidification and for "soft-impingement" of particles via diffusion fields are consistent with experiment.Comment: 4 pages, 4 figures, accepted to PR

    Real life use of prostacyclin analog (Iloprost), a multi-centric survey data from the scleroderma study group Emilia Romagna (Sclero-RER) and review of the literature

    Get PDF
    Background and aim: Iloprost is recommend worldwide for the treatment of RP and the healing of DUs. The aim of this study is to report the regimens of Iloprost administered in different rheumatological centers within the same regional Health System Methods: A questionnaire exploring different items related to the use of Iloprost was developed and reviewed by three expert rheumatologists. The questionnaire was distributed as an online survey to all local SSc referral centers in Emilia-Romagna (Italy). Data are reported as percentage or median with interquartile range (IQR), as appropriate. An updated review of world literature on this topic was also carried out. Results: All the invited centers completed the survey. There were both local (8) and university hospitals (4). The majority (58%) had a rheumatologist as head physician. All centers used Iloprost: a single monthly administration was the most common treatment (75%). The cycle lasted 1 [IQR 1-2] days with a 0.5-2.0 ng/Kg/min dose according to the drug tolerance of the patients. There were overall 68 spots (beds, reclining armchair, or simple armchair); 2.0 [1.5-4.0] patients were able to receive Iloprost at the same time. University Hospitals had more physicians at their disposal than local hospitals but less paramedic personnel (respectively: 1.8 vs 1.2 physicians, 1.5 vs 2.1 nurses). Conclusions: These observations were in line with the majority of previous studies reporting different regimens, comparing similar (but not identical) dose and schedule administration, however, despite differences being at times substantial, no standard infusion method is yet available. (www.actabiomedica.it)

    Rethinking the import-productivity nexus for Italian manufacturing

    Get PDF
    We provide evidence on the firm level productivity effects of imports of intermediates. By exploiting a large panel of Italian manufacturing firms, we are able to separately explore the role of importing from high and low income countries. Importing does not permanently affect the firm productivity growth. This finding holds both when we test for the import entry by means of Propensity Score Matching techniques and when we analyse the import intensity within a dynamic panel data model framework. On the contrary, we confirm the existence of self-selection into importing. Also, our evidence supports the learning-by-exporting effects in Italian manufacturing and we prove that this result is robust to the control of firm import activity

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

    Get PDF
    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30
    corecore