675 research outputs found

    On the estimation of the bed-material transport and budget along a river segment: application to the Middle Loire River, France

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    Sediment load and budgets are a fundamental component of the process-based hydromorphological framework developed by the REFORM project, and are needed to accurately assess the current condition of a river, its sensitivity to change, and its likely future evolutionary trajectory. This paper presents an evaluation of three different methods for estimating both bedload sediment transport and bed-material budget within river channels, using the Middle Loire River as a case study. The first method is based on the stream power concept and does not need any hydraulic calculations. It yields estimates of the sediment transport in the same order of magnitude as measurements but poor results for the bed-material budget in terms of magnitude and tendency. For the second method, hydraulic parameters are computed using the Manning–Strickler equation (or a 1D hydraulic model for steady flow). It provides useful indicators for understanding river dynamics but does not yield significant improvements compared to the first method. The third method uses 1D numerical software for water flow and river bed evolution. It yields the most accurate results for both sediment transport and bed evolution but requires more data and overall more work to construct the model. Guidance is provided on the amount of data required, the competence needed to build the models, and the predictive capability of each of the methods

    Chromosomal control of non-gliadin proteins from the 70% ethanol extract of wheat endosperm

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    The non-gliadin fraction of the 70% ethanol extracts of compensated nulli-tetrasomics and ditelosomics of Triticum aestivum cv. Chinese Spring has been analyzed by combined electrofocusing and electrophoresis. Seventeen of the 21 protein map components of the euploid have been ascribed to eight chromosomes: 4A, 3BS, 6BS, 7BS, 3D, 4D, 5D and 7DS. The relationship of the different map components with other proteins previously associated with the same chromosomes is discusse

    Clinic blood pressure, ambulatory blood pressure and cardiac structural alterations in nonagenarians and in centenarians

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    Scant information is available on the alterations in cardiac structure and function characterizing very elderly people as well as on their relationships to clinic and ambulatory blood pressure (BP) values. In 106 subjects aged 95.3 ± 3.7 years (mean ± standard deviation, 89 nonagenarians and 17 centenarians) in good clinical conditions and living in the municipal house in Milan, we measured, along with standard clinical and laboratory variables, clinic BP, 24-h ambulatory BP and echocardiographic parameters. Forty-five of the recruited subjects were normotensive individuals, whereas 61 were treated hypertensive patients. Subjects with an age greater than 90 years showed clinic systolic (SBP) and diastolic BP (DBP) both within the normal range, with values that for clinic SBP were slightly lower than the corresponding 24-h SBP (120.8 ± 15.9 vs 128.0 ± 16.3 mmHg) and for DBP slightly higher (69.7 ± 8.8 vs 64.9 ± 8.0 mmHg). Daytime average mean BP was slightly lower than night-time average mean BP, indicating the attenuation of the BP reduction during night-time. Left ventricular mass index (LVMI) was increased and significantly related to both 24-h and clinic BP values (r = 0.24, p < 0.04 and r = 0.20, p < 0.05). Thus in nonagenarians and centenarians, abnormalities in left ventricular pattern are of frequent detection and may be related both to the ageing process and to BP load. © 2012 Scandinavian Foundation for Cardiovascular Research
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