376 research outputs found

    Towards an integrated management of water resource issues in the Dyle catchment (Scheldt basin, Belgium): the European MULINO project (MULti-sectoral, INtegrated and Operational decision support system for sustainable use of water resources at the catchment scale)

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    The pressure on water resources is continuously increasing in Europe. If a great deal of scientific knowledge is available in many fields, this knowledge is often treated in isolation. To support the scientific basis for integrated water management, the MULINO project, an acronym for MULti-sectoral, Integrated and Operational decision support system (DSS) for the sustainable use of water resources at the catchment scale, funded by the European Union, is currently executed. The purpose of the MULINO project is to provide a tool to improve the integrated management of water resources at the catchment scale, following the requirements of the EU Water Framework Directive (WFD, J.O.CE, 2000). The DSS developed is a computer system based on hydrological modelling, multi-disciplinary indicators and multi-criteria evaluation procedures. The underlying design of the DSS is based on the Driving Forces-Pressures-State-Impact-Responses framework for reporting on environmental issues (EEA, 1999; OECD, 1993). One case study is the 700 kmÂČ Dyle catchment situated in the centre of Belgium (50°38N 4°45E) and part of the Scheldt basin. A coupling of an integrated hydrological model (SWAT: Soil and Water Assessment Tool, Arnold et al., 1993) with land use change modelling (SFARMMOD, Audsley et al., 1979) is developed in close collaboration with local end users and stakeholders. This work will provide a useful tool to analyse water resources management alternatives and to assist local managers in complex problems such as flooding, nitrate and pesticides contamination of waters, as to identify solutions for the implementation of the WFD at the catchment scale

    Uncertainty, sensitivity analysis and the role of data based mechanistic modeling in hydrology

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    International audienceIn this paper, we discuss the problem of calibration and uncertainty estimation for hydrologic systems from two points of view: a bottom-up, reductionist approach; and a top-down, data-based mechanistic (DBM) approach. The two approaches are applied to the modelling of the River Hodder catchment in North-West England. The bottom-up approach is developed using the TOPMODEL, whose structure is evaluated by global sensitivity analysis (GSA) in order to specify the most sensitive and important parameters; and the subsequent exercises in calibration and validation are carried out in the light of this sensitivity analysis. GSA helps to improve the calibration of hydrological models, making their properties more transparent and highlighting mis-specification problems. The DBM model provides a quick and efficient analysis of the rainfall-flow data, revealing important characteristics of the catchment-scale response, such as the nature of the effective rainfall nonlinearity and the partitioning of the effective rainfall into different flow pathways. TOPMODEL calibration takes more time and it explains the flow data a little less well than the DBM model. The main differences in the modelling results are in the nature of the models and the flow decomposition they suggest. The "quick'' (63%) and "slow'' (37%) components of the decomposed flow identified in the DBM model show a clear partitioning of the flow, with the quick component apparently accounting for the effects of surface and near surface processes; and the slow component arising from the displacement of groundwater into the river channel (base flow). On the other hand, the two output flow components in TOPMODEL have a different physical interpretation, with a single flow component (95%) accounting for both slow (subsurface) and fast (surface) dynamics, while the other, very small component (5%) is interpreted as an instantaneous surface runoff generated by rainfall falling on areas of saturated soil. The results of the exercise show that the two modelling methodologies have good synergy; combining well to produce a complete modelling approach that has the kinds of checks-and-balances required in practical data-based modelling of rainfall-flow systems. Such a combined approach also produces models that are suitable for different kinds of application. As such, the DBM model can provides an immediate vehicle for flow and flood forecasting; while TOPMODEL, suitably calibrated (and perhaps modified) in the light of the DBM and GSA results, immediately provides a simulation model with a variety of potential applications, in areas such as catchment management and planning

    Evaluation of Expression of the PTEN Gene, Oestrogen and Progesterone Receptors as Diagnostic and Predictive Factors in Endometrial Cancer

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    Endometrial cancer belongs to the commonest malignancy in females after breast cancer, malignant neoplasm of female genitals in Europe and North America but there is still not significant improvement as far as the curability of this neoplasm is concerned, especially its advanced forms. That is why there is need to define new factors that could be not only diagnostic but also predictve factors. In present study we analyzed the mRNA PTEN expression by quantitative real-time polymerase chain reaction (Q-PCR) in 123 women of endometrial carcinoma and 14 women of control group. Moreover we assessed oestrogen (ER) and progesterone receptors (PgR) in all cases. We defined the correlation between expression of PTEN gene and receptors and between PTEN expression and maturity grade of cancer. Neoplasm advancement grade G1 was diagnosed in 82.11 % of patients (n = 101), G2 in 9.76 % of patients (n = 12) and G3 in 8.13 % of patients (n = 10). Presence of ER and PgR and decreased expression of PTEN gene was found in majority of patients with endometrial cancer (79.12 % and 59.34 % respectively) and the most numerous group was with weak expression of ER and strong expression of PgR. There was no statistically significant difference in gene expression depending on receptors expression nor maturity grade of cancer (p > 0.05). Evaluation of expression of PTEN gene may turn out to be a very useful tool aimed at qualifying patients for different therapies of endometrial cancer and at searching of new diagnostic and therapeutic methods of this cancer independently on its receptor status nor maturity grade of cancer

    XRCC2 R188H (rs3218536), XRCC3 T241M (rs861539) and R243H (rs77381814) single nucleotide polymorphisms in cervical cancer risk

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    Human Papillomavirus (HPV) is the main cause of cervical cancer and its precursor lesions. Transformation may be induced by several mechanisms, including oncogene activation and genome instability. Individual differences in DNA damage recognition and repair have been hypothesized to influence cervical cancer risk. The aim of this study was to evaluate whether the double strand break gene polymorphisms XRCC2 R188H G>A (rs3218536), XRCC3 T241M C>T (rs861539) and R243H G>A (rs77381814) are associated to cervical cancer in Argentine women. A case control study consisting of 322 samples (205 cases and 117 controls) was carried out. HPV DNA detection was performed by PCR and genotyping of positive samples by EIA (enzyme immunoassay). XRCC2 and 3 polymorphisms were determined by pyrosequencing. The HPV-adjusted odds ratio (OR) of XRCC2 188 GG/AG genotypes was OR = 2.4 (CI = 1.1-4.9, p = 0.02) for cervical cancer. In contrast, there was no increased risk for cervical cancer with XRCC3 241 TT/CC genotypes (OR = 0.48; CI = 0.2-1; p = 0.1) or XRCC3 241 CT/CC (OR = 0.87; CI = 0.52-1.4; p = 0.6). Regarding XRCC3 R243H, the G allele was almost fixed in the population studied. In conclusion, although the sample size was modest, the present data indicate a statistical association between cervical cancer and XRCC2 R188H polymorphism. Future studies are needed to confirm these findings.Fil: Perez, Luis Orlando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Crivaro, Andrea Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Barbisan, Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Poleri, Lucía Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Golijow, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin

    An Association between Single Nucleotide Polymorphisms of Lys751Gln ERCC2 Gene and Ovarian Cancer in Polish Women

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    Aim. The aim of this study was to evaluate the role of the Lys751Gln (rs13181) ERCC2 gene polymorphism in clinical parameters and the risk for development of ovarian cancer. Material and Methods. The study consisted of 430 patients with ovarian cancer (mean age: 53.2 ± 10.11) and 430 healthy subjects (mean age: 50.31 ± 18.21). Analysis of the gene polymorphisms was performed using the PCR-based restriction fragment length polymorphism (PCR-RFLP). The odds ratios (ORs) and 95% confidence intervals (CIs) for each genotype and allele were calculated. Results. The results obtained indicate that the genotype Gln/Gln is associated with an increased risk of ovarian cancer (OR 5.01; 95% CI 3.37-7.43; < 0.0001). Association of Lys751Gln polymorphism with histological grading showed increased ERCC2 Gln/Gln (OR = 6.96; 95% CI 3.41-14.21; < 0.0001) genotype in grading 1 as well as Gln allele overrepresentation (OR = 4.98; 95% CI 3.37-7.40; < 0.0001) in G1 ovarian patients. Finally, with clinical FIGO staging under evaluation, an increase in ERCC2 Gln/Gln homozygote frequencies in staging I and Gln allele frequencies in SI were observed. Conclusion. On the basis of these results, we conclude that ERCC2 gene polymorphism Lys751Gln may be associated with an increased risk of ovarian carcinoma

    Time-reversal method and cross-correlation techniques by normal mode theory: a three-point problem

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    International audienceSince its beginning in acoustics, the Time-Reversal method (hereafter referred as TR) has been explored by different studies to locate and characterize seismic sources in elastic media. But few authors have proposed an analytical analysis of the method, especially in the case of an elastic medium and for a finite body such as the Earth. In this paper, we use a normal mode approach (for general 3-D case and degenerate modes in 1-D reference model) to investigate the convergence properties of the TR method. We first investigate a three-point problem, with two fixed points which are the source and the receiver and a third one corresponding to a changing observation point. We extend the problem of a single channel TR experiment to a multiple channel and multiple station TR experiment. We show as well how this problem relates to the retrieval of Green's function with a multiple source cross-correlation and also the differences between TR method and cross-correlation techniques. Since most of the noise sources are located close to the surface of the Earth, we show that the time derivative of the cross-correlation of long-period seismograms with multiple sources at the surface is different from the Green's function. Next, we show the importance of a correct surface-area weighting of the signal resent by the stations according to a Voronoi tessellation of the Earth surface. We use arguments based on the stationary phase approximation to argue that phase-information is more important than amplitude information for getting a good focusing in TR experiment. Finally, by using linear relationships between the time-reversed displacement (resp. strain wavefields) and the components of a vector force source (resp. a moment tensor source), we show how to retrieve force (or moment tensor components) of any long period tectonic or environmental sources by time reversal

    Geo-neutrinos: A systematic approach to uncertainties and correlations

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    Geo-neutrinos emitted by heat-producing elements (U, Th and K) represent a unique probe of the Earth interior. The characterization of their fluxes is subject, however, to rather large and highly correlated uncertainties. The geochemical covariance of the U, Th and K abundances in various Earth reservoirs induces positive correlations among the associated geo-neutrino fluxes, and between these and the radiogenic heat. Mass-balance constraints in the Bulk Silicate Earth (BSE) tend instead to anti-correlate the radiogenic element abundances in complementary reservoirs. Experimental geo-neutrino observables may be further (anti)correlated by instrumental effects. In this context, we propose a systematic approach to covariance matrices, based on the fact that all the relevant geo-neutrino observables and constraints can be expressed as linear functions of the U, Th and K abundances in the Earth's reservoirs (with relatively well-known coefficients). We briefly discuss here the construction of a tentative "geo-neutrino source model" (GNSM) for the U, Th, and K abundances in the main Earth reservoirs, based on selected geophysical and geochemical data and models (when available), on plausible hypotheses (when possible), and admittedly on arbitrary assumptions (when unavoidable). We use then the GNSM to make predictions about several experiments ("forward approach"), and to show how future data can constrain - a posteriori - the error matrix of the model itself ("backward approach"). The method may provide a useful statistical framework for evaluating the impact and the global consistency of prospective geo-neutrino measurements and Earth models.Comment: 17 pages, including 4 figures. To appear on "Earth, Moon, and Planets," Special Issue on "Neutrino Geophysics," Proceedings of Neutrino Science 2005 (Honolulu, Hawaii, Dec. 2005
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