392 research outputs found

    Operational Numerical Weather Prediction systems based on Linux cluster architectures

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    The progress in weather forecast and atmospheric science has been always closely linked to the improvement of computing technology. In order to have more accurate weather forecasts and climate predictions, more powerful computing resources are needed, in addition to more complex and better-performing numerical models. To overcome such a large computing request, powerful workstations or massive parallel systems have been used. In the last few years, parallel architectures, based on the Linux operating system, have been introduced and became popular, representing real“high performance–low cost” systems. In this work the Linux cluster experience achieved at the Laboratory for Meteorology and Environmental Analysis (LaMMA-CNR-IBIMET) is described and tips and performances analysed

    Early Experience with the New Ovation Alto Stent Graft in Endovascular Abdominal Aortic Aneurysm Repair

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    Introduction: Since 2010, the Ovation Abdominal Stent Graft System has offered a new sealing concept, achieved by a sealing ring filled with polymer 13 mm from the renal arteries. In the latest version, called Ovation Alto, the sealing ring is relocated 6 mm closer to the top of the fabric. This study describes the early clinical outcomes, after CE Mark approval in August 2020, of endovascular aneurysm repair with the Alto endograft. Report: Eleven patients underwent endovascular aneurysm repair with implantation of Ovation Alto endografts. All patients were male, and the median age was 75 (IQR 5.5) years. Hostile proximal aortic neck (<10 mm) was identified in six cases (54.5%). All procedures were performed using bilateral percutaneous approaches with no groin complications. The median procedure time was 58 (IQR 7.2) minutes, the median contrast volume used was 65 (IQR 4.2) mL, and the median blood loss 40 (IQR 12.4) mL. Technical success was achieved in all cases. The median stent graft landing distance between the top of the fabric and the lowest renal artery was 1.4 (IQR 0.8) mm. No intra-operative high flow endoleaks were registered. At one and six month follow up, there was 100% clinical success (no type I/III endoleak, sac enlargement, stent graft migration, polymer leakage, abdominal aortic aneurysm related mortality, or secondary intervention). Discussion: Initial experience confirms the early technical and clinical success of the new Ovation Alto stent graft. Technical modifications to the endograft could allow for accommodation of a more comprehensive range of anatomies on label. Further studies are needed to evaluate long term durability outcomes

    High Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios Are Associated with a Higher Risk of Hemodialysis Vascular Access Failure

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    Our aim was to determine the predictive role of the preoperative neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in vascular access malfunctioning in patients who had undergone their first native arterio-venous fistula (AVF) for hemodialysis. Methods: This was a single-center retrospective observational study. All patients who underwent the procedure of the creation of a first native AVF for hemodialysis from January 2019 to December 2020 were considered eligible to be part of this study. Reinterventions for AVF malfunctioning were registered and the population was subdivided into two groups with respect to AVF malfunctioning. ROC curves were obtained to find the appropriate cut-off values for the NLR and PLR. A multivariate analysis was used to identify the independent predictors for an AVF malfunction. Kaplan–Meier curves were used to evaluate the AVF patency rates. A total of 178 patients were enrolled in the study, of them 70% (n = 121) were male. The mean age was 67.5 ± 12 years. Reinterventions for AVF malfunctioning were performed on 102 patients (57.3%). An NLR > 4.21 and a PLR > 208.8 was selected as the cut-off for AVF malfunctioning. The study population was divided into two groups depending on the NLR and PLR values of the individual. For the NLR < 4.21 group, the AVF patency rates were 90.7%, 85.3%, and 84% at the 3-, 6-, and 12-month follow-up, respectively, and 77.5%, 65.8%, and 39.3% at 3, 6, and 12 months for the NLR > 4.21 group, respectively (p < 0.0001). For the PLR < 208.8 group, the patency rates were 85.6%, 76.7%, and 67.7% at the 3-, 6-, and 12-month follow-up. For the PLR > 208.28 group, the patency rates were 80.8%, 71.2%, and 50.7% for the 3-, 6-, and 12-month follow-up, respectively (p = 0.014). The multivariate analysis highlighted that diabetes mellitus, the neutrophil count, the lymphocyte count, and the NLR were independent risk factors for an AVF failure. In our experience, the NLR and PLR are useful markers for the stratification of vascular access failure in hemodialysis patients. The inexpensive nature and ready availability of the values of these biomarkers are two points of strength for everyday clinical practice

    Prevalence of erectile dysfunction in patients with abdominal aortic aneurysm: an exploratory study

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    Erectile dysfunction (ED) is defined as the recurrent inability to achieve and maintain a satisfactory erection for sexual intercourse. Many studies have highlighted that ED shares common cardiovascular risk factors with cardiovascular disease. No data are reported about the prevalence of ED in patients with the abdominal aortic aneurysm (AAA). The aim of our study was to investigate the preoperative information given about sexual functions of patients undergoing endovascular aneurysm repair (EVAR) and to compare it with the presence and severity of steno-occlusive atherosclerotic lesions of the pelvic arterial tree at pre-operative Computed Tomography Angiography (CTA).Methods: We prospectively enrolled all men patients who underwent elective EVAR from September to November 2021. Preoperative ED was evaluated using the International Index of Erectile Function (IIEF-5) questionnaire. Preoperative imaging was routinely performed with CTA scan of the abdominal aorta and iliac-pelvic district. An innovative score of pelvic arterial disease associated to AAA was defined, dividing the iliac district in 4 zones attributing a grading of severity for each zone bilaterally (score ranges 0–24). Linear regression analysis was used to correlate IIEF-5 score to anatomical score of pelvic arterial steno-occlusive disease.Results: A total of 25 patients were enrolled. Median age was 74 ± 5.3 years. IIEF-5 average score was 14.8 ± 7.1. Eight cases (32%) had severe ED; one case (4%) had moderate, five patients (20%) had mild to moderate ED; five patients (20%) had mild ED, and 6 (24%) patients had no ED. CTA evaluation revealed an average anatomical score of 7.9 ± 4.5. Pelvic disease was considered moderate-severe in 20 cases (80%) and not significant in 20% (five cases). Linear regression analysis confirmed the hypothesis that a more diseased pelvic arterial tree was correlated to a more severe ED (Y = -1.531* × + 26.35 [slope CI: -1.946 to-1.117, p < 0.0001]).Conclusion: Although typically unreported, the prevalence of ED associated to AAA was found to be high. A vasculogenic origin of ED in patients with AAA is plausible and may be easily confirmed by the evaluation of pelvic arterial distribution at angio-CT performed for EVAR planning. Our proposed “MAPPING AND SCORING SHEET” may help to identify the vasculogenic origin of ED in AAA patients

    Endovascular Abdominal Aortic Aneurysm Repair With Ovation Alto Stent Graft: Protocol for the ALTAIR (ALTo endogrAft Italian Registry) Study

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    Background: Since 2010, the Ovation Abdominal Stent Graft System has offered an innovative sealing option for abdominal aortic aneurysm (AAA) by including a sealing ring filled with polymer 13 mm from the renal arteries. In August 2020, the redesigned Ovation Alto, with a sealing ring 6 mm closer to the top of the fabric, received CE Mark approval. Objective: This registry study aims to evaluate intraoperative, perioperative, and postoperative results in patients treated by the Alto stent graft (Endologix Inc.) for elective AAA repair in a multicentric consecutive experience. Methods: All consecutive eligible patients submitted to endovascular aneurysm repair (EVAR) by Alto Endovascular AAA implantation will be included in this analysis. Patients will be submitted to EVAR procedures based on their own preferences, anatomical features, and operators experience. An estimated number of 300 patients submitted to EVAR with Alto stent graft should be enrolled. It is estimated that the inclusion period will be 24 months. The follow-up period is set to be 5 years. Full data sets and cross-sectional images of contrast-enhanced computed tomography scan performed before EVAR, at the first postoperative month, at 24 or 36 months, and at 5-year follow-up interval will be reported in the central database for a centralized core laboratory review of morphological changes. The primary endpoint of the study is to evaluate the technical and clinical success of EVAR with the Alto stent graft in short- (90-day), mid- (1-year), and long-term (5-year) follow-up periods. The following secondary endpoints will be also addressed: operative time; intraoperative radiation exposure; contrast medium usage; AAA sac shrinkage at 12-month and 5-year follow-up; any potential role of patients' baseline characteristics, valuated on preoperative computed tomography angiographic study, and of device configuration (number of component) in the primary endpoint. Results: The study is currently in the recruitment phase and the final patient is expected to be treated by the end of 2023 and then followed up for 5 years. A total of 300 patients will be recruited. Analyses will focus on primary and secondary endpoints. Updated results will be shared at 1- and 3-5-year follow-ups. Conclusions: The results from this registry study could validate the safety and effectiveness of the new design of the Ovation Alto Stent Graft. The technical modifications to the endograft could allow for accommodation of a more comprehensive range of anatomies on-label

    The 8 and 9 September 2002 flash flood event in France: a model intercomparison

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    Within the framework of the European Interreg IIIb Medocc program, the HYDROPTIMET project aims at the optimization of the hydrometeorological forecasting tools in the context of intense precipitation within complex topography. Therefore, some meteorological forecast models and hydrological models were tested on four Mediterranean flash-flood events. One of them occured in France where the South-eastern ridge of the French “Massif Central”, the Gard region, experienced a devastating flood on 8 and 9 September 2002. 24 people were killed during this event and the economic damage was estimated at 1.2 billion euros. To built the next generation of the hydrometeorological forecasting chain that will be able to capture such localized and fast events and the resulting discharges, the forecasted rain fields might be improved to be relevant for hydrological purposes. In such context, this paper presents the results of the evaluation methodology proposed by Yates et al. (2005) that highlights the relevant hydrological scales of a simulated rain field. Simulated rain fields of 7 meteorological model runs concerning with the French event are therefore evaluated for different accumulation times. The dynamics of these models are either based on non-hydrostatic or hydrostatic equation systems. Moreover, these models were run under different configurations (resolution, initial conditions). The classical score analysis and the areal evaluation of the simulated rain fields are then performed in order to put forward the main simulation characteristics that improve the quantitative precipitation forecast. The conclusions draw some recommendations on the value of the quantitative precipitation forecasts and way to use it for quantitative discharge forecasts within mountainous areas

    Design and acceptability assessment of a new reversible orthosis

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    We present a new device aimed at being used for upper limb rehabilitation. Our main focus was to design a robot capable of working in both the passive mode (i.e. the robot shall be strong enough to generate human-like movements while guiding the weak arm of a patient) and the active mode (i.e. the robot shall be able of following the arm without disturbing human natural motion). This greatly challenges the design, since the system shall be reversible and lightweight while providing human compatible strength, workspace and speed. The solution takes the form of an orthotic structure, which allows control of human arm redundancy contrarily to clinically available upper limb rehabilitation robots. It is equipped with an innovative transmission technology, which provides both high gear ratio and fine reversibility. In order to evaluate the device and its therapeutic efficacy, we compared several series of pointing movements in healthy subjects wearing and not wearing the orthotic device . In this way, we could assess any disturbing effect on normal movements. Results show that the main movement characteristics (direction, duration, bell shape profile) are preserved. ©2008 IEEE

    Impacts of Climate Change on SOC Dynamic and Crop Yield of Italian Rainfed Wheat-Maize Cropping Systems Managed with Conventional or Conservation Tillage Practices

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    There is still uncertainty on the ability of conservation tillage (i.e., reduced- RT and no till - NT) in contributing to the resilience of cropping systems to climate change pressures (Powlson et al 2016). RT or NT can improve soil physical and biological proprieties thus increasing water holding capacity and fertility, stabilizing soil structure and enhancing soil biodiversity and functions. They are also frequently proposed as mitigation practices as they can contribute to increase soil organic carbon (SOC) compared to conventional moldboard ploughing practices (Gonzalez-Sanchezet al., 2012). However, SOC increase occurs mostly in the upper soil layer but not always in the deeper profile (Haddaway et al., 2016) where SOC measurements are less frequently measured. In this study, we used data obtained from long term field experiments(LTE) coupled with three crop simulation models in order to assess the long-term effects of different tillage management practices on crop yield and on changes in SOC stocks in both superficial (0-20cm) and deeper layers (20-50cm) in Mediterranean rainfed cereal cropping systems at current and future climate scenarios

    [Occupational therapy in rheumatoid arthritis: short term prospective study in patients treated with anti-TNF-alpha drugs].

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    Objective: to assess the effect of occupational therapy (OT) in rheumatoid arthritis (RA) patients treated with anti- TNF-alpha drugs in a short-term open controlled prospective study. Methods: 31 RA subjects [(M/F=5/26; mean age= 56 (range=28-73) years; mean disease duration= 165 (range =15- 432) months], treated with anti- TNF-alpha drugs, were allocated to OT (n=15) or control (n=16) group. We evaluated at entry and 12 weeks the following outcome parameters including Health Assessment Questionnaire (HAQ), Short-Form Health Survey (SF-36), Global Health (GH), Ritchie index, number of swollen or tender joints, pain, patient and physician disease activity, Disease Activity Score (DAS28), erythrocyte sedimentation rate (ESR), C-reactive protein CRP) and the correct adherence to items regarding activity daily living (ADL). Results: at baseline, OT and control group had similar demographic and clinical features. After 12 weeks, the changes from baseline of main outcome parameters were not significantly different between the two groups. After 12 weeks, in 7 out of 11 items regarding ADL, the percentage of patients showing a correct adherence was significantly increased in OT group only. Moreover at the end of the study, the OT group showed a correct adherence to 8 out of 11 ADL items in an higher percentage of patients respect to the control group. Conclusion: our study sustains that OT improves self-management but not main parameters of disease activity or functional capacity. Nevertheless educational intervention should be considered as a useful tool in conjunction with pharmacological treatment
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