37 research outputs found
Glomerular filtration rate and prevalence of chronic kidney disease in Wilmsâ tumour survivors
Glomerular filtration rate (GFR) was evaluated in 32 Wilmsâ tumour survivors (WTs) in a cross-sectional study using 99 Tc-diethylene triamine pentaacetic acid (99 Tc-DTPA) clearance, the Schwartz formula, the new Schwartz equation for chronic kidney disease (CKD), cystatin C serum concentration and the Filler formula. Kidney damage was established by beta-2-microglobulin (B-2-M) and albumin urine excretion, urine sediment and ultrasound examination. Blood pressure was measured. No differences were found between the mean GFR in 99 Tc-DTPA and the new Schwartz equation for CKD (91.8â±â11.3 vs. 94.3â±â10.2 ml/min/1.73 m2 [pâ=â0.55] respectively). No differences were observed between estimated glomerular filtration rate (eGFR) using the Schwartz formula and the Filler formula either (122.3â±â19.9 vs. 129.8â±â23.9 ml/min/1.73 m2 [pâ=â0.28] respectively). Increased urine albumin and B-2-M excretion, which are signs of kidney damage, were found in 7 (22%) and 3 (9.4%) WTs respectively. Ultrasound signs of kidney damage were found in 14 patients (43%). Five patients (15.6%) had more than one sign of kidney damage. Eighteen individuals (56.25%) had CKD stage I (10 with signs of kidney damage; 8 without). Fourteen individuals (43.75%) had CKD stage II (6 with signs of kidney damage; 8 without). The new Schwartz equation for CKD better estimated GFR in comparison to the Schwartz formula and the Filler formula. Furthermore, the WT survivors had signs of kidney damage despite the fact that GFR was not decreased below 90 ml/min/1.73 m2 with 99 Tc- DTPA
Too wet and too dry? Uncertainty of DEM as a potential source of significant errors in a model-based water level assessment in riparian and mire ecosystems
On the choice of calibration periods and objective functions: A practical guide to model parameter identification
Forty Years of Water Research at the Institute of Geophysics, Polish Academy of Sciences
Influence of Land-Use and Water Management Practices on Water Levels in the Middle River Vistula
Changes in Catchment Hydrology Caused by Changes in the Environment: A Contribution of the Water Resources Department, Institute of Geophysics PAS
Modeling of floods: state of the art and research challenges
International audienceThis chapter presents a state of the art review and research challenges in modeling flood propagation and floodplain inundation. The challenges for flood inundation models are directly linked to the representation of flow processes, to the formulation of theoretical physical laws and to practical considerations. First, we review the various structures of coupled spatially distributed hydrological-hydraulic models and the corresponding spatial representation of flow processes. Second, we present the theoretical basis of 1-D and 2-D Saint-Venant "shallow water" equations with overbank flow, the approximation of Saint-Venant models such as the Diffusive Wave and the Kinematic Wave models and then discuss the domains and limits of applications of each type of models. Practical considerations linked to numerical solution schemes, boundary conditions and model parameterization, calibration, validation and uncertainty analysis were also considered. Finally, the discussion addresses the research challenges for guiding the modeler, according to the principle of parsimony, in seeking the simplest modeling strategy capable of (i) a realistic representation of the physical processes, (ii) matching the performances of more complex models and (iii) providing the right answers for the right reasons