5,171 research outputs found
Graphical method to predict the dynamic response of FM receivers
Graphical method determines the rms threshold point, saturation point, and operating points for an FM receiver utilizing various modulation indices and degrees of submodulation
Modelling the runoff response in the Mulde catchment (Germany)
International audienceThe paper presents two different levels of regionalization used to represent the spatial distribution of landscape parameters for the hydrological modelling of the Mulde. The aim of this investigation was to find out how the discretisation level affects quality of modelling with the hydrological modelling system J2000. Furthermore we improved our understanding of the applicability and reliability of the distributed model J2000 on the macro-scale. Spatial information was aggregated in two different discretisation levels: subbasins (SB) and hydrological response polygons (HRP). A J2000 simulation was carried out for both discretisation levels based on a 1 year calibration and a 3 year validation period. Simulations performed well for both levels of spatial discretisation. The results seemed to be better in the more complex discretisation approach, where the Nash-Sutcliffe coefficient was higher. We can conclude that our first results show more accurate simulations produced by the HRP discretisation approach, the visual inspection shows a better application of the SB approach to the reproduction of the base flow
What Are Gene Patents and Why Are People Worried about Them?
This article examines what it means to patent a gene. Numerous ethical concerns have been raised about the effects of such patents on clinical medical practice as well as on research and development. We describe what kinds of inventions are covered by human gene patents, give several examples and summarize the small body of empirical research performed in the US examining the effects of these patents. There is little evidence that early fears about gene patenting placing substantial restraints on research and clinical medicine have come to fruition. Nonetheless, there are areas of concern, and policy makers, physicians and the public should be alert to ensure that the net social benefits of patenting human genes are maintained
A field study from the Oderbruch, Germany
The behavior of organophosphates and ethers during riverbank filtration and
groundwater flow was assessed to determine their suitability as organic
tracers. Four sampling campaigns were conducted at the Oderbruch polder,
Germany to establish the presence of chlorinated flame retardants (TCEP, TCPP,
TDCP), non-chlorinated plasticizers (TBEP, TiBP, TnBP), and hydrophilic ethers
(1,4-dioxane, monoglyme, diglyme, triglyme, tetraglyme) in the Oder River,
main drainage ditch, and anoxic aquifer. Selected parameters were measured in
order to determine the hydro-chemical composition of both, river water and
groundwater. The results of the study confirm that organophosphates (OPs) are
more readily attenuated during bank filtration compared to ethers. Both in the
river and the groundwater, TCPP was the most abundant OP with concentrations
in the main drainage ditch ranging between 105 and 958 ng L−1. 1,4-dioxane,
triglyme, and tetraglyme demonstrated persistent behavior during bank
filtration and in the anoxic groundwater. In the drainage ditch concentrations
of 1,4-dioxane, triglyme, and tetraglyme ranged between 1090 and 1467 ng L− 1,
37 and 149 ng L− 1, and 496 and 1403 ng L− 1, respectively. A positive
correlation was found for the inorganic tracer chloride with 1,4-dioxane and
tetraglyme. These results confirm the possible application of these ethers as
environmental organic tracers. Both inorganic and organic compounds showed
temporal variability in the surface- and groundwater. Discharge of the river
water, concentrations of analytes at the time of infiltration and attenuation
were identified as factors influencing the variable amounts of the analytes in
the surface and groundwater. These findings are also of great importance for
the production of drinking water via bank filtration and natural and
artificial groundwater recharge as the physicochemical properties of ethers
create challenges in their removal
The distribution of effective tax burdens in four EU countries
National policymakers are increasingly aware that their tax policy options are constrained by international tax competition. Important features of national tax systems - notably the tax mix, tax rates and rules which define the tax base - will influence decisions of firms and individuals regarding the location and (re)structuring of economic activities. The aim of the present paper is twofold: Firstly, we detail the tax mix of four member states of the European Union (Germany, The Netherlands, Spain and United Kingdom). Secondly, the paper aims to trace the distribution of the tax burden over rich and poor households in these four countries. Although tax mix and tax rates differ considerably among the four countries included in the study, the distribution of tax burdens proves to be amazingly similar.Distribution of tax burden, European Union; tax mix of Germany, the Netherlands, Spain and United Kingdom
Empirical developments in retraction
This study provides current data on key questions about retraction of scientific articles. Findings confirm that the rate of retractions remains low but is increasing. The most commonly cited reason for retraction was research error or inability to reproduce results; the rate from research misconduct is an underestimate, since some retractions necessitated by research misconduct were reported as being due to inability to reproduce. Retraction by parties other than authors is increasing, especially for research misconduct. Although retractions are on average occurring sooner after publication than in the past, citation analysis shows that they are not being recognised by subsequent users of the work. Findings suggest that editors and institutional officials are taking more responsibility for correcting the scientific record but that reasons published in the retraction notice are not always reliable. More aggressive means of notification to the scientific community appear to be necessary
Model system development and uncertainty for the provisionary management of extreme floods in large river basins
International audienceA research project is introduced in which a modelling system is being developed to quantify risks of extreme flooding in large river basins. In the system, computer models and modules are coupled to simulate the functional chain: hydrology - hydraulics - polder diversion - dyke failure - flooding - damage estimate - risk assessment. In order to reduce uncertainty in flood frequency analyses, data sets are complimented with information from historical chronicles and artwork. Probable maximum precipitation and discharge are calculated to indicate upper bounds of meteorological and hydrological extremes. Uncertainty analysis is investigated for different degrees of model complexity and compared at different basin scales
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