518 research outputs found

    Effect analysis of transient scenarios for successful water management strategies

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    Recent scenario studies on water management focus on one or two projection years and the effects on the water system and functions. The future is however more complex and dynamic. Therefore, we analyse transient scenarios in order to evaluate the performance of water management strategies. Current available simulation tools are not suitable for this purpose. Therefore, we have developed and used a tool to simulate 50-100 year long time series and that is good and fast enough to simulate the effects of these scenarios and strategies on the water system and the interaction with the human system. We present the first step by means of a case study

    Estimates of future discharges of the river Rhine using two scenario methodologies: direct versus delta approach

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    International audienceSimulations with a hydrological model for the river Rhine for the present (1960?1989) and a projected future (2070?2099) climate are discussed. The hydrological model (RhineFlow) is driven by meteorological data from a 90-years (ensemble of three 30-years) simulation with the HadRM3H regional climate model for both present-day and future climate (A2 emission scenario). Simulation of present-day discharges is realistic provided that (1) the HadRM3H temperature and precipitation are corrected for biases, and (2) the potential evapotranspiration is derived from temperature only. Different methods are used to simulate discharges for the future climate: one is based on the direct model output of the future climate run (direct approach), while the other is based on perturbation of the present-day HadRM3H time series (delta approach). Both methods predict a similar response in the mean annual discharge, an increase of 30% in winter and a decrease of 40% in summer. However, predictions of extreme flows differ significantly, with increases of 10% in flows with a return period of 100 years in the direct approach and approximately 30% in the delta approach. A bootstrap method is used to estimate the uncertainties related to the sample size (number of years simulated) in predicting changes in extreme flows

    Mutation Testing as a Safety Net for Test Code Refactoring

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    Refactoring is an activity that improves the internal structure of the code without altering its external behavior. When performed on the production code, the tests can be used to verify that the external behavior of the production code is preserved. However, when the refactoring is performed on test code, there is no safety net that assures that the external behavior of the test code is preserved. In this paper, we propose to adopt mutation testing as a means to verify if the behavior of the test code is preserved after refactoring. Moreover, we also show how this approach can be used to identify the part of the test code which is improperly refactored

    AML1, the Target of Multiple Chromosomal Translocations in Human Leukemia, Is Essential for Normal Fetal Liver Hematopoiesis

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    AbstractThe AML1–CBFβ transcription factor is the most frequent target of chromosomal rearrangements in human leukemia. To investigate its normal function, we generated mice lacking AML1. Embryos with homozygous mutations in AML1 showed normal morphogenesis and yolk sac–derived erythropoiesis, but lacked fetal liver hematopoiesis and died around E12.5. Sequentially targeted AML1−/− ES cells retained their capacity to differentiate into primitive erythroid cells in vitro; however, no myeloid or erythroid progenitors of definitive hematopoietic origin were detected in either the yolk sac or fetal livers of mutant embryos. Moreover, this hematopoietic defect was intrinsic to the stem cells in that AML1−/− ES cells failed to contribute to hematopoiesis in chimeric animals. These results suggest that AML1-regulated target genes are essential for definitive hematopoiesis of all lineages

    Klimaatverandering en laagwater op de Maas

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    Heeft de verwachte klimaatverandering invloed op de frequentie en omvang van laagwater in de zomer in de Maas. Modelstudies op grond van klimaatscenario's en analyse van historische data m.b.t. neerslag en waterafvoer tonen aan dat er, met de huidige behoefte aan Maaswater, een grote kans is dat aanzienlijke economische schade ontstaat als gevolg van langdurig lage afvoeren (zelfs zonder klimaatverandering

    Nitrogen source apportionment for the catchment, estuary and adjacent coastal waters of the Scheldt.

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    Using the systems approach framework (SAF), a coupled model suite was developed for simulating land-use decision making in response to nutrient abatement costs and water and nutrient fluxes in the hydrological network of the Scheldt River, and nutrient fluxes in the estuary and adjacent coastal sea. The purpose was to assess the efficiency of different long-term water quality improvement measures in current and future climate and societal settings, targeting nitrogen (N) load reduction. The spatial-dynamic model suite consists of two dynamically linked modules: PCRaster is used for the drainage network and is combined with ExtendSim modules for farming decision making and estuarine N dispersal. Model predictions of annual mean flow and total N concentrations compared well with data available for river and estuary (r² ≥ 0.83). Source apportionment was carried out to societal sectors and administrative regions; both households and agriculture are the major sources of N, with the regions of Flanders and Wallonia contributing most. Load reductions by different measures implemented in the model were comparable (~75% remaining after 30 yr), but costs differed greatly. Increasing domestic sewage connectivity was more effective, at comparatively low cost (47% remaining). The two climate scenarios did not lead to major differences in load compared with the business-as-usual scenario (~88% remaining). Thus, this spatially explicit model of water flow and N fluxes in the Scheldt catchment can be used to compare different long-term policy options for N load reduction to river, estuary, and receiving sea in terms of their effectiveness, cost, and optimal location of implementation

    Senescent cells in the development of cardiometabolic disease

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    Purpose of review Senescent cells have recently been identified as key players in the development of metabolic dysfunction. In this review, we will highlight recent developments in this field and discuss the concept of targeting these cells to prevent or treat cardiometabolic diseases. Recent findings Evidence is accumulating that cellular senescence contributes to adipose tissue dysfunction, presumably through induction of low-grade inflammation and inhibition of adipogenic differentiation leading to insulin resistance and dyslipidaemia. Senescent cells modulate their surroundings through their bioactive secretome and only a relatively small number of senescent cells is sufficient to cause persistent physical dysfunction even in young mice. Proof-of-principle studies showed that selective elimination of senescent cells can prevent or delay the development of cardiometabolic diseases in mice. Summary The metabolic consequences of senescent cell accumulation in various tissues are now unravelling and point to new therapeutic opportunities for the treatment of cardiometabolic diseases

    Українська шляхта між польським та українським етносами

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    Appearance and existence of the Ukrainian gentry relates to the traditions of Polish political culture, so during the whole period of its life it was between the Ukrainian and the Polish ethnic groups. Polanisation of the Ukrainian gentry begins at the date when some of the Ukrainian territories become a part of Poland and strengthens after Cossack revolution in the middle and at the end of the 16th century. Especially this process becomes effective at the beginning of the 18th century when a great part of gentry from other Polish lands migrates to Pravoberezhia (right-banked Ukraine). Nevertheless, having captured upper class and partially middle class of the Ukrainian gentry, polanisation mainly influenced consciousness and less religion of the lower class of the Ukrainian gentry. As for ethnoculture and language local gentry was mostly Ukrainian and it assimilated numerous Polish gentlemen-immigrants

    Left Ventricular Endocardial Pacing Improves Resynchronization Therapy in Canine Left Bundle-Branch Hearts

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    Background— We investigated the benefits of the more physiological activation achieved by left ventricular (LV) endocardial pacing (ENDO) as compared with conventional epicardial (EPI) LV pacing in cardiac resynchronization therapy. Methods and Results— In 8 anesthetized dogs with experimental left bundle-branch block, pacing leads were positioned in the right atrium, right ventricle, and at 8 paired (EPI and ENDO) LV sites. Systolic LV pump function was assessed as LVdP/dtmax and stroke work and diastolic function as LVdP/dtmin. Electrical activation and dispersion of repolarization were determined from 122 epicardial and endocardial electrodes and from analysis of the surface ECG. Overall, ENDO-biventricular (BiV) pacing more than doubled the degree of electrical resynchronization and increased the benefit on LVdP/dtmax and stroke work by 90% and 50%, respectively, as compared with EPI-BiV pacing. During single-site LV pacing, the range of AV intervals with a >10% increase in LV resynchronization (79�31 versus 32�24 ms, P <0.05) and LVdP/dtmax (92�29 versus 63�39 ms) was significantly longer for ENDO than for EPI pacing. EPI-BiV but not ENDO-BiV pacing created a significant (40�21 ms) transmural dispersion of repolarization. Conclusions— Data from this acute animal study indicate that the use of an endocardial LV pacing electrode may increase the efficacy of resynchronization therapy as compared with conventional epicardial resynchronization therapy

    Fermi Surface Properties of Low Concentration Cex_{x}La1x_{1-x}B6_{6}: dHvA

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    The de Haas-van Alphen effect is used to study angular dependent extremal areas of the Fermi Surfaces (FS) and effective masses of Cex_{x}La1x_{1-x}B6% _{6} alloys for xx between 0 and 0.05. The FS of these alloys was previously observed to be spin polarized at low Ce concentration (xx = 0.05). This work gives the details of the initial development of the topology and spin polarization of the FS from that of unpolarized metallic LaB6_{6} to that of spin polarized heavy Fermion CeB6_{6} .Comment: 7 pages, 9 figures, submitted to PR
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