962 research outputs found

    Regional Shifts of Crops Within the U.S. During the 20th Century

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    Cost-effectiveness of irbesartan in diabetic nephropathy: a systematic review of published studies

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    Background. To review published studies on the cost-effectiveness of the use of irbesartan for treatment of advance overt nephropathy in patients with type 2 diabetes and hypertension. Methods. Articles were identified based on a search of the PubMed databases using the keywords ‘irbesartan', ‘ESRD', ‘cost-effectiveness', ‘nephropathy' and ‘costs', and by personal communication with the authors. Only studies published in the last 10 years were included. All costs data from the cost-effectiveness studies were inflated to 2003 Euros using published governmental conversion tables. Results. Seven published studies were identified, spanning the following country settings: the US, Belgium and France, Germany, Hungary, Italy, Spain, and the UK. In each, the same pharmacoeconomic model was adapted using country-specific data to project and evaluate the clinical and cost outcomes of the treatment arms of the Irbesartan in Diabetic Nephropathy Trial (IDNT) (irbesartan, amlodipine or standard blood pressure control). Mean time to onset of ESRD was 8.23 years for irbesartan, 6.82 years for amlodipine and 6.88 years for the control (values were the same for Belgium, France, Germany, Hungary, Italy and Spain as transition probabilities for progression to ESRD were all derived from the IDNT). Mean cumulative incidence of ESRD was 36% with irbesartan, 49% with amlodipine and 45% with control treatment. Treatment with irbesartan was projected to improve life expectancy compared to both amlodipine and control in all seven published studies. Analysis of total lifetime costs showed that irbesartan treatment was cost saving compared to the other two treatment regimens, due to the associated reduction in ESRD cases. Cost savings with irbesartan became evident very early; after 2-3 years of treatment in most settings. Conclusions. Modelling studies based on the IDNT published to date suggest that irbesartan treatment in patients with type 2 diabetes, hypertension and advanced nephropathy is both life- and cost-saving compared to amlodipine or contro

    The influence of cycloplegic in objective refraction

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    The purpose of this study was to compare refractions measured with an autorefractor and retinoscopy in cycloplegic and non-cycloplegic eyes. The objective refractions were performed in 199 right eyes from 199 healthy young adults with a mean age of 21.6 ±2.66 years. The measurements were performed first without cycloplegia and repeated 30 minutes later with cycloplegia. Data were analyzed using Fourier decomposition of the power profile. More negative values of component M and J0 were give by non-cycloplegic autorefraction compared to cycloplegic autorefraction (p<0.001). However more positive values were given by non-cycloplegic autorefraciton regarding to the J45 vector, althought this differences were not statistically significant (p=0.233). Regarding retinoscopy, more negative values of component M where obtained with non-cycloplegic retinoscopy (p<0.001); for the cylindrical vectors J0 and J45 the retinoscopy without cycloplegic yields more negative values (p= 0.234; p= 0.112, respectively). Accepting that differences between cycloplegic and non-cycloplegic retinoscopy are only due to accommodative response, present results confirm that when performed by an experienced clinician, retinoscopy is a more reliable method to obtain objective start point for refraction under non-cycloplegic conditions

    Mechanisms of Cognitive Impairment in Cerebral Small Vessel Disease: Multimodal MRI Results from the St George's Cognition and Neuroimaging in Stroke (SCANS) Study.

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    Cerebral small vessel disease (SVD) is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI) is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115), and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50). On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD

    Interactive Generation of Time-Evolving Snow-Covered Landscaped with Avalanches

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    We introduce a novel method for interactive generation of visually consistent, snow-covered landscapes and provide control of their dynamic evolution over time. Our main contribution is the real-time phenomenological simulation of avalanches and other user-guided events, such as tracks left by Nordic skiing, which can be applied to interactively sculpt the landscape. The terrain is modeled as a height field with additional layers for stable, compacted, unstable, and powdery snow, which behave in combination as a semi-viscous fluid. We incorporate the impact of several phenomena, including sunlight, temperature, prevailing wind direction, and skiing activities. The snow evolution includes snow-melt and snow-drift, which affect stability of the snow mass and the probability of avalanches. A user can shape landscapes and their evolution either with a variety of interactive brushes, or by prescribing events along a winter season time-line. Our optimized GPU-implementation allows interactive updates of snow type and depth across a large (10×10km) terrain, including real-time avalanches, making this suitable for visual assets in computer games. We evaluate our method through perceptual comparison against exiting methods and real snow-depth data

    Cerebral microbleeds a guide to detection and interpretation

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    Cerebral microbleeds (CMB) are increasingly recognized neuroimaging findings, occurring with cerebrovascular disease, dementia, and normal aging. Recent years have seen substantial progress, particularly in developing newer MRI methodologies for CMB detection and applying them to population-based elderly samples. This review focuses on these recent developments and their impact on two major questions: how CMB are detected, and how they should be interpreted. There is now ample evidence that prevalence and number of detected CMB varies with MRI characteristics such as pulse sequence, sequence parameters, spatial resolution, magnetic field strength, and post-processing, underlining the importance of MRI technique in interpreting studies. Recent investigations using sensitive techniques find the prevalence of CMB detected in community-dwelling elderly to be surprisingly high. We propose procedural guidelines for identifying CMB and suggest possible future approaches for elucidating the role of these common lesions as markers for, and potential contributors to, small vessel brain disease

    La macération pelliculaire dans la vinification en blanc - Incidence sur la composante volatile des vins

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    Skin contact in white wine processing- Effects on the volatile constituents of winesWines were made from three different white vine cultivars, Chenin, Chardonnay, Bourboulenc by standard white wine processing, with and without skin contact, and their volatile constituents were analysed using gas chromatography standard procedures. 61 substances were identified and quantified in quadruplicate. One-way analyses of variance for each component were performed in which skin contact wine was compared to the control wine for each vine cultivar. Skin contact was shown to increase significantly most volatile components except volatile acids. In attempt to classify the wines investigated, principal component analysis was conducted using the amounts of compounds differing significantly in variance analysis
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