A multi-scale method to assess pesticide contamination risks in agricultural watersheds

The protection of water is now a major priority for environmental managers, especially around drinkingpumping stations. In view of the new challenges facing water agencies, we developed a method designedto support their public policy decision-making, at a variety of different spatial scales. In this paper, wepresent this new spatial method, using remote sensing and a GIS, designed to determine the contami-nation risk due to agricultural inputs, such as pesticides. The originality of this method lies in the useof a very detailed spatial object, the RSO (Reference Spatial Object), which can be aggregated to manyworking and managing scales. This has been achieved thanks to the pixel size of the remote sensing, witha grid resolution of 30 m × 30 m in our application.The method – called PHYTOPIXAL – is based on a combination of indicators relating to the environmen-tal vulnerability of the surface water environment (slope, soil type and distance to the stream) and theagricultural pressure (land use and practices of the farmers). The combination of these indicators for eachpixel provides the contamination risk. The scoring of variables was implemented according knowledgein literature and of experts.This method is used to target specific agricultural input transfer risks. The risk values are first calculatedfor each pixel. After this initial calculation, the data are then aggregated for decision makers, accordingto the most suitable levels of organisation. These data are based on an average value for the watershedareas.In this paper we detail an application of the method to an area in the hills of Southwest France. Weshow the pesticide contamination risk by in areas with different sized watersheds, ranging from 2 km2to 7000 km2, in which stream water is collected for consumption by humans and animals. The resultswere recently used by the regional water agency to determine the protection zoning for a large pumpingstation. Measures were then proposed to farmers with a view to improving their practices.The method can be extrapolated to different other areas to preserve or restore the surface water

Working Paper 21-08 - Impact of the EU Energy and Climate Package on the Belgian energy system and economy - Study commissioned by the Belgian federal and three regional authorities

In order to prepare for the negotiations on the EU Energy and Climate Package, the Federal Planning Bureau was asked by the Belgian federal and regional authorities to conduct a study on the impact of the January 2008 European Commission's proposal. In the course of this study, various scenarios were run. Next to a baseline, two main alternative scenarios were scrutinised: the 20/20 and 30/20 target scenarios, standing for an EU reduction of respectively 20% and 30% of GHG emissions in the year 2020 compared to the level of 1990 and a 20% mandatory EU share of RES in Gross Final Energy Demand in 2020. The report then includes an analysis of the impact of both scenarios on the Belgian energy system and economy as well as on GHG emissions.Energy policy, Climate policy, Economic efficiency, Long-term energy projections, Greenhouse gas emissions, Macroeconomic impact

Multilabeled versions of Sperner's and Fan's lemmas and applications

We propose a general technique related to the polytopal Sperner lemma for proving old and new multilabeled versions of Sperner's lemma. A notable application of this technique yields a cake-cutting theorem where the number of players and the number of pieces can be independently chosen. We also prove multilabeled versions of Fan's lemma, a combinatorial analogue of the Borsuk-Ulam theorem, and exhibit applications to fair division and graph coloring.Comment: 21 pages, 2 figure

Analysis of the energy harvesting performance of a piezoelectric bender outside its resonance

When the frequency of the source of vibration of a piezolectric generator is significantly different from its eigenfrequency, the dielectric power losses become prominent and decrease the amount of power which is practically harvested. For off-resonance vibrating frequencies, the optimal operating conditions can be obtained with a Maximum Power Point Tracking method. This paper introduces complex phasors in the study of power conversion for piezoelectric generators. These complex phasors are used to describe three strategies which help simplify the tracking of the optimal generator output power for vibration frequencies which are away from resonance. Experimental results obtained on a prototype illustrate and confirm the approach with the phasor approaches illustrate and confirm the success of the proposed optimal power tracking strategies. Finally, we show that the efficiency results of each strategy depend on whether they are used inside or outside a frequency bandwidth around the eigenfrequency, and that the length of this bandwidth depends on the excitation amplitude.IRCICA Stimtac Project, INRIA Mint Project

Organizational and Cognitive Duality of the firm with community concept

On the basis of the recent concepts of epistemic communities and communities of practice, we show that the firm can be defined according to a form of double duality: cognitive and organisational. The interest of this approach is to put ahead the differentiated behavior from the manager and the entrepreneur inside the firm. It also puts in light the important questions concerning the organisational tensions under the vision of the knowledge-based economies.Creation of knowledge, Learning process, Routines, Community of Practice, Epistemic Community, Knowledge conversion modes, Knowledge management.

Geophysical investigation of the Pb-Zn deposit of Lontzen-Poppelsberg, Belgium

The drillhole information from the Lontzen-Poppelsberg site has demonstrated three orebodies and has allowed the estimation of the extension of the lodes, their dip, and the location at the ground surface. The localisation of the lodes makes them excellent targets for further exploration with geophysics. This deposit is classified as a Mississippi Valley Type (MVT) deposit. It consists mainly of Pb-Zn-Fe sulphides that display contrasting values in resistivity, chargeability, density, and magnetic susceptibility, with regards to the sedimentary host rocks. The dipole-dipole direct current (DC) resistivity and induce polarization (IP) profiles have been collected and inverted to successfully delineate the Pb-Zn mineralization and the geological structures. Short-spacing EM34 electromagnetic conductivity data were collected mainly on the top of Poppelsberg East lode and have revealed a conductive body matching with the geologically modelled mineralization. Gravity profiles have been carried out perpendicularly to the lode orientation; they show a strong structural anomaly. High resolution ground magnetic data were collected over the study area, but they showed no anomaly over the ore deposits. The geophysical inversion results are complementary to the model based on drill information, and allow us to refine the delineation of the mineralization. The identification of the geophysical signatures of this deposit permits targeting new possible mineralization in the area

Simulation study of brain blood flow regulation by intra-cortical arterioles in an anatomically accurate large human vascular network. Part II: Flow variations induced by global or localized modifications of arteriolar diameters

In a companion paper (Lorthois et al., Neuroimage, inpress),we perform the first simulations of blood flow in an anatomically accurate large human intra-cortical vascular network (~10000 segments), using a 1D non-linear model taking into account the complex rheological properties of blood flow in microcirculation. This model predicts blood pressure, blood flow and hematocrit distributions, volumes of functional vascular territories, regional flow at voxel and network scales, etc. Using the same approach, we study flow reorganizations induced by global arteriolar vasodilations (an isometabolic global increase in cerebral blood flow). For small to moderate global vasodilations, the relationship between changes in volume and changes in flowis in close agreement with Grubb's law, providing a quantitative tool for studying the variations of its exponent with underlying vascular architecture. A significant correlation between blood flow and vascular structure at the voxel scale, practically unchanged with respect to baseline, is demonstrated. Furthermore, the effects of localized arteriolar vasodilations, representative of a local increase in metabolic demand, are analyzed. In particular, localized vasodilations induce flowchanges, including vascular steal, in the neighboring arteriolar trunks at small distances (< 300 μm), while their influence in the neighboring veins is much larger (about 1 mm), which provides an estimate of the vascular point spread function.More generally, for the first time, the hemodynamic component of various functional neuroimaging techniques has been isolated from metabolic and neuronal components, and a direct relationship with several known characteristics of the BOLD signal has been demonstrated

SiC coatings grown by liquid injection chemical vapor deposition using single source metal-organic precursors

SiC coatings have been grown by direct liquid injection of organosilanes in a hot-wall chemical vapor deposition reactor (DLICVD). 1,3-disilabutane (DSB) and polysilaethylene (PSE) were used as single-source precursors. Amorphous and stoichiometric SiC coatings were deposited under low pressure on various substrates in the temperature range of 923–1073 K. Thickness gradients due to the temperature profiles and the precursor depletion were observed along the reactor axis but the thickness uniformity could be improved as a function of the deposition conditions. Growth rates as high as 90 μm·h−1 were obtained using pure precursors. The injection of PSE solutions in toluene significantly reduces the deposition rate due to the decrease of the PSE mole fraction but allows a better control of the growth rates and the microstructure of coatings. They exhibit a smooth surface morphology and a very dense structure. The films grown using pure precursors exhibit an Si:C atomic ratio equal to 1:1 while those using toluene solutions are slightly C-rich (54 at.% C). The presence of solvent vapor in the CVD reactor becomes a source of carbon contamination at deposition temperatures equal to or higher than 1073 K. The influence of the growth conditions is discussed, in particular the presence of toluene vapor

Olfactory responses to aphid and host plant volatile releases: (E)-beta-farnesene an effective kairomone for the predator Adalia bipunctata.

peer reviewedThe volatiles released from several aphid and host plant species, alone or associated, were studied for their infochemical role in prey location. Using a four-arm olfactometer, the attraction of several combinations of three aphid (Myzus persicae, Acyrthosiphon pisum, and Brevicoryne brassicae) and three plant (Vicia faba, Brassica napus, and Sinapis alba) species toward Adalia bipunctata larvae and adults was observed. Both predatory larvae and adults were attracted only by A. pisum and M. persicae when they were crushed, whatever the host plant. (E)-beta-farnesene, the aphid alarm pheromone, was the effective kairomone for the ladybird. Plant leaves alone (V. faba, B. napus, and S. alba) or in association with nonstressed whole aphids (the three species) did not have any attraction for the predator. The B. brassicae specialist aphid is the only prey that was not attracted to A. bipunctata larvae and adults, even if they were crushed. Release of B. brassicae molecules similar to the host plant allelochemicals was demonstrated by GC-MS analysis. The lack of behavioral response of the ladybird at short distance toward the cruciferous specialist aphid was related only to the absence of (E)-beta-farnesene in the aphid prey volatile pattern

Simulation study of brain blood flow regulation by intra-cortical arterioles in an anatomically accurate large human vascular network : Part I : Methodology and baseline flow

Hemodynamically based functional neuroimaging techniques, such as BOLD fMRI and PET, provide indirect measures of neuronal activity. The quantitative relationship between neuronal activity and the measured signals is not yet precisely known, with uncertainties remaining about the relative contribution by their metabolic and hemodynamic components. Empirical observations have demonstrated the importance of the latter component and suggested that micro-vascular anatomy has a potential influence. The recent development of a 3D computer-assisted method for micro-vascular cerebral network analysis has produced a large quantitative library on the microcirculation of the human cerebral cortex (Cassot et al., 2006), which can be used to investigate the hemodynamic component of brain activation through fluid dynamic modeling. For this purpose, we perform the first simulations of blood flow in an anatomically accurate large human intra-cortical vascular network (~10000 segments), using a 1D non-linear model taking account of the complex rheological properties of blood flow in microcirculation. This model predicts blood pressure, blood flow and hematocrit distributions, as well as volumes of functional vascular territories, and regional flow at voxel and network scales. First, the influence of the prescribed boundary conditions (BCs) on the baseline flow structure is investigated, highlighting relevant lower- and upper-bound BCs. Independent of these BCs, large heterogeneities of baseline flow from vessel to vessel and from voxel to voxel, are demonstrated. These heterogeneities are controlled by the architecture of the intra-cortical vascular network. In particular, a correlation between the blood flow and the proportion of vascular volume occupied by arterioles or venules, at voxel scale, is highlighted. Then, the extent of venous contamination downstream to the sites of neuronal activation is investigated, demonstrating a linear relationship between the catchment surface of the activated area and the diameter of the intra-cortical draining vein