1,778 research outputs found

    The Impact of Spatial Heterogeneity in Land Use Practices and Aquifer Characteristics on Groundwater Conservation Policy Cost

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    Estimation of agricultural policy cost for a given level of groundwater conservation requires the establishment of an accurate baseline condition. This is especially critical when the benefits and cost of any conservation program are generally estimated relative to the status quo policy or baseline situation. An inaccurate baseline estimate will lead to poor estimates of potential water conservation savings and agricultural policy cost. Over a 60-year planning horizon per acre net present value is as much as 29.8% higher for a study area when aquifer characteristics are assumed to be homogenous and set to their average area value than when the heterogeneity in aquifer characteristics is explicitly modeled.Aquifer Modeling, Economics, Resource /Energy Economics and Policy,

    The regularized 3D Boussinesq equations with fractional Laplacian and no diffusion

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    In this paper, we study the 3D regularized Boussinesq equations. The velocity equation is regularized \`a la Leray through a smoothing kernel of order α\alpha in the nonlinear term and a β\beta-fractional Laplacian; we consider the critical case α+β=54\alpha+\beta=\frac{5}{4} and we assume 12<β<54\frac 12 <\beta<\frac 54. The temperature equation is a pure transport equation, where the transport velocity is regularized through the same smoothing kernel of order α\alpha. We prove global well posedness when the initial velocity is in HrH^r and the initial temperature is in HrβH^{r-\beta} for r>max(2β,β+1)r>\max(2\beta,\beta+1). This regularity is enough to prove uniqueness of solutions. We also prove a continuous dependence of the solutions on the initial conditions.Comment: 28 pages; final version accepted for publication in Journal of Differential Equation

    The GiSAS study: Rationale and design of pragmatic randomized controlled trial on aripiprazole, olanzapine and haloperidol in the long-term treatment of schizophrenia

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    Given the controversy about the comparative efficacy of first- compared with second-generation antipsychotics in the treatment of schizophrenia, more large-scale evidence is needed to guide clinicians in their prescriptions. Most randomized controlled trials (RCTs) were conducted in centers of excellence on highly selected samples, poorly representative of real-world patients, and often suffered conflicts of interest as they were sponsored by drug companies. The primary aim of the present study is to compare the effectiveness of haloperidol, olanzapine and aripiprazole in a representative sample of schizophrenia patients. The GiSAS trial is an open-label, independent, pragmatic RCT in Italian community-based public psychiatric services. At least 260 patients meeting the DSM-IV criteria for schizophrenia will be randomly allocated to one of the study drugs and followed up for one year. A two-year observational phase will follow. The primary outcome for tolerability will be the onset of metabolic syndrome. The primary endpoint for effectiveness will be discontinuation of antipsychotic monotherapy. Secondary measures include global functioning, time to discontinuation due to side-effects, change of lipid profile, extrapyramidal symptoms and other adverse effects. In the last four years, the GiSAS study group has been working to implement this multicenter RCT. The trial mechanism is now fully functional and working. As of end of February 2011, 260 subjects were randomized by 54 study investigators in 33 out of 43 participating centers

    Can People Sleep Too Much? Effects of Extended Sleep Opportunity on Sleep Duration and Timing

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    Many people are concerned about whether they are getting “enough” sleep, and if they can “sleep too much.” These concerns can be approached scientifically using experiments probing long-term (i.e., multi-night) sleep homeostatic processes, since homeostatic processes move the system toward its physiological setpoint (i.e., between “not enough” and “too much”). We analyzed sleep data from two human studies with sleep opportunities much longer than people usually stay in bed (i.e., conditions in which sleep homeostatic responses could be documented): sleep opportunities were 14–16 h per day for 3–28 days. Across the nights of the extended sleep opportunities, total sleep duration, Rapid Eye Movement (REM) sleep duration and non-REM sleep durations decreased and sleep latency increased. Multiple nights were required to reach approximately steady-state values. These results suggest a multi-day homeostatic sleep process responding to self-selected insufficient sleep duration prior to the study. Once steady state-values were reached, there were large night-to-night variations in total sleep time and other sleep metrics. Our results therefore answer these concerns about sleep amount and are important for understanding the basic physiology of sleep and for two sleep-related topics: (i) the inter-individual and intra-individual variability are relevant to understanding “normal” sleep patterns and for people with insomnia and (ii) the multiple nights of sleep required for recovery from insufficient sleep from self-selected sleep loss is important for public health and other efforts for reducing the adverse effects of sleep loss on multiple areas of physiology

    Meta-analysis on the Effect of Mild Primary Hyperparathyroidism and Parathyroidectomy upon Arterial Stiffness

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    Context: Current data about the cardiovascular manifestations of mild primary hyperparathyroidism (pHPT) are often conflicting. Pulse wave velocity (PWV) is the gold standard for assessing aortic stiffness, and it predicts cardiovascular morbidity and mortality. Objective: Primary outcomes were to investigate if mild pHPT was associated with higher PWV and if parathyroidectomy (PTX) reduced PWV in mild pHPT. Secondary outcome was to investigate blood pressure changes after PTX. Methods: Sources were PubMed, Google Scholar, SCOPUS, Web of Science, and the Cochrane Library. Eligible studies included reports of PWV in patients with mild pHPT and controls, or in patients with mild pHPT before and after PTX. Two investigators independently identified eligible studies and extracted data. Pooled mean difference (MD) was the summary effect measure. Data were presented in forest plots with outlier and influential case diagnostics. Nine observational studies and one randomized clinical trial were selected, including 433 patients with mild pHPT, 171 of whom underwent PTX, and 407 controls. PWV was significantly higher in mild pHPT than in controls (MD = 1.18, 0.67 to 1.68, P <. 0001). Seven studies evaluated the effect of PTX on PWV. PTX significantly reduced PWV (MD =-0.48,-0.88 to-0.07, P =. 022). Conclusion: Aortic stiffness is increased in patients with mild pHPT, supporting the notion that mild pHPT is also associated with adverse cardiovascular manifestations. PTX significantly reduced arterial stiffness in mild pHPT, indicating that the benefit of PTX over cardiovascular manifestations should not be dismissed but it deserves further studies

    A new generation photodetector for astroparticle physics: the VSiPMT

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    The VSiPMT (Vacuum Silicon PhotoMultiplier Tube) is an innovative design we proposed for a revolutionary photon detector. The main idea is to replace the classical dynode chain of a PMT with a SiPM (G-APD), the latter acting as an electron detector and amplifier. The aim is to match the large sensitive area of a photocathode with the performance of the SiPM technology. The VSiPMT has many attractive features. In particular, a low power consumption and an excellent photon counting capability. To prove the feasibility of the idea we first tested the performance of a special non-windowed SiPM by Hamamatsu (MPPC) as electron detector and current amplifier. Thanks to this result Hamamatsu realized two VSiPMT industrial prototypes. In this work, we present the results of a full characterization of the VSiPMT prototype

    Dietary fat intake as a risk factor for the development of diabetes. Multinational, multicenter study of the Mediterranean Group for the Study of Diabetes (MGDS)

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    In the context of the Multinational MGSD Nutrition Study, three groups of subjects were studied: 204 subjects with recently diagnosed diabetes(RDM),42subjectswithundiagnoseddiabetes(UDM)(AmericanDiabetesAssociation criteria—fasting plasma glucose [FPG] 126 mg/dl), and 55 subjects with impaired fasting glucose(IFG)(FPG 110and126mg/dl).Eachgroupwascomparedwithacontrolgroupof nondiabetic subjects, matched one by one for center, sex, age, and BMI. Nutritional habits were evaluated by a dietary history method, validated against the 3-day diet diary. In RDM, the questionnaire referred to the nutritional habits before the diagnosis of diabetes. Demographic data were collected, and anthropometrical and biochemical measurements were taken. RESULTS— Compared with control subjects, RDM more frequently had a family history of diabetes(49.0vs.14.2%;P0.001),exercisedless(exerciseindex53.5vs.64.4;P0.01),and more frequently had sedentary professions (47.5 vs. 27.4%; P 0.001). Carbohydrates contributed less to their energy intake (53.5 vs. 55.1%; P 0.05), whereas total fat (30.2 0.5 vs. 27.8 0.5%; P 0.001) and animal fat (12.2 0.3 vs. 10.8 0.3%; P 0.01) contributed moreandtheplant-to-animalfatratiowaslower(1.50.1vs.1.80.1;P0.01).UDMmore frequentlyhadafamilyhistoryofdiabetes(38.1vs.19.0%;P0.05)andsedentaryprofessions (58.5vs.34.1%;P0.05),carbohydratescontributedlesstotheirenergyintake(47.61.7vs. 52.81.4%;P0.05),totalfat(34.71.5vs.30.41.2%;P0.05)andanimalfat(14.2 0.9 vs. 10.6 0.7%; P 0.05) contributed more, and the plant-to-animal fat ratio was lower (1.6 0.2 vs. 2.3 0.4; P 0.05). IFG differed only in the prevalence of family history of diabetes (32.7 vs. 16.4%; P 0.05). CONCLUSIONS— Our data support the view that increased animal fat intake is associated with the presence of diabetes

    Elevated myocardial and lymphocyte GRK2 expression and activity in human heart failure.

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    The G protein-coupled receptor kinase-2 (GRK2 or beta-ARK1) regulates beta-adrenergic receptors (beta-ARs) in the heart, and its cardiac expression is elevated in human heart failure (HF). We sought to determine whether myocardial levels and activity of GRK2 could be monitored using white blood cells, which have been used to study cardiac beta-ARs. Moreover, we were interested in determining whether GRK2 levels in myocardium and lymphocytes may be associated with beta-AR dysfunction and HF severity.In myocardial biopsies from explanted failing human hearts, GRK activity was inversely correlated with beta-AR-mediated cAMP production (R(2)=-0.215, P<0.05, n=24). Multiple regression analysis confirmed that GRK activity participates with beta-AR density to regulate catecholamine-sensitive cAMP responses. Importantly, there was a direct correlation between myocardial and lymphocytes GRK2 activity (R(2)=0.5686, P<0.05, n=10). Lymphocyte GRK activity was assessed in HF patients with various ejection fractions (EFs) (n=33), and kinase activity was significantly higher in patients with lower EFs and was higher with increasing NYHA class (P<0.001).Myocardial GRK2 expression and activity are mirrored by lymphocyte levels of this kinase, and its elevation in HF is associated with the loss of beta-AR responsiveness and appears to increase with disease severity. Therefore, lymphocytes may provide a surrogate for monitoring cardiac GRK2 in human HF

    When prosthetic joint infection may lead to premalignant colorectal lesion detection

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    Osteoarthritis (OA) is a common musculoskeletal disorder that affects millions of people worldwide, and total knee arthroplasty (TKA) is a common treatment for advanced OA. However, joint replacement surgeries may lead to complications such as deep vein thrombosis (DVT), surgical site infection, and prosthetic joint infection (PJI). Our objective is to discuss a Streptococcus bovis group (SBG) PJI case after TKA and its possible consequences in clinical practice. We describe a 67-year-old female who underwent TKA and developed initial complications including wound hematoma, symptomatic anemia, and acute DVT. Further investigations because of knee pain persistence and inflammatory signs post TKA revealed the presence of Staphylococcus aureus in the synovial and scar tissues from the knee and SBG in the periprosthetic membrane from the revision surgery, as well as mitral infective endocarditis and a large stenosing villous polypoid lesion in the ascending colon. SBG osteoarticular infection post TKA is a rare condition, but it may be associated with severe diseases. This article highlights the link between SBG and colorectal cancer (CRC) and emphasizes the importance of an echocardiogram and a colonoscopy for early detection and prompt treatment of infective endocarditis and CRC. This diagnostic workup should be performed even in the absence of symptoms, for early diagnosis and increased chance of cure. A multidisciplinary approach, involving orthopedists, infectious disease specialists, cardiologists, and gastroenterologists, among others, is advised to effectively manage SBG infections and improve patient outcomes
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