Assessment of groundwater quality recovery strategies using nitrate transport modelling. Application to the Saône alluvial formations (Tournus, Saône-et-Loire)

To assess the efficiency of different agro-environmental strategies used to reduce groundwater pollution by nitrates, transport modelling in soils and groundwater has been carried out on two withdrawal areas in an alluvial plain. In a first time, the agro-environmental model AgriFlux allowed the simulation of water and nitrates fluxes flowing to groundwater. This model was calibrated for each agro-pedological unit of the studied territory. In a second time, the application of the hydrogeological model MODFLOW-MT3D allowed the simulation of nitrate transport in groundwater for the 1980-2004 period. This soil-groundwater coupled modelling has shown that soil nature is the first factor that conditions the vulnerability to nitrates. Thus, nitrate leaching occurs preferentially under sandy soils. Efficiency of different agro-environmental operations for groundwater quality recovery was quantified. The best results are obtained by combination of (1) grassland re-installation on sandy agricultural lots located in near well protection perimeter and (2) fertilization reduction on sandy agricultural lots located in the well alimentation area upstream the near protection perimeter. On other soils, the effect of grassland on groundwater quality improvement is more limited. Nevertheless, the control of nitrate fertilisation remains essential and is justified in both near and far well protection perimeters. Modelling thus allows optimising and priorizing agro-environmental actions in alluvial agricultural zones. [Comte J.-C., Banton O., Kockmann F., Villard A., Creuzot G. (2006), Assessment of groundwater quality recovery strategies using nitrate transport modelling. Application to the Saône alluvial formations (Tournus, Saône-et-Loire), Ingénieries Eau-Agriculture-Territoires, 45, 15-28]

Temps et Oralité dans le Conte Oral

This article addresses the question of narrative tense usage in a particular variety of performed oral narration in modern French, i.e. oral storytelling. We examine the narrative tense systems used in both traditional and new storytelling, comparing these with well-attested oral and written patterns and with theoretical models such as Benveniste's, Weinrich's and Revaz's. We examine briefly some of the key functions of the tense alternations attested, again comparing these to patterns in other types of discourse, and conclude by considering the nature of the « orality » in question.

L'Europe et les partis politiques nationaux: Les lecons d'un

European integration remains a 'non-cleavage' in relation to the Lipset-Rokkan model, as it has not produced significant restructurings of national party systems. Yet, while not effecting the terms of interparty competition, Europe has nevertheless come to occupy an increasingly large place in national political debates. Since the early 1990s, Euroscepticisms have taken root, to varying degrees, across the entire continent. This article analyses the rise of these Eurosceptic tendencies, examining the phenomenon in terms of both the Europeanisation of national political life and the wider emergence of forms of protest politics. The analysis demonstrates how European questions have been absorbed into established party structures, while at the same time pointing towards a renewed research agenda which pays greater attention both to the discursive dimension of political life and to the roles played by national parties as European actors.

Use of A192621 to provide evidence for involvement of endothelin ET(B)-receptors in endothelin-1-mediated cardiomyocyte hypertrophy.

Increased plasma levels of endothelin-1 correlate with the severity of left ventricular hypertrophy in vivo. The aim of the study was to determine the relative contribution of stimulation of endothelin ETA and endothelin ETB receptors, and the associated activation of protein kinase C, to the hypertrophic response initiated by endothelin-1 in adult rat ventricular cardiomyocytes maintained in culture (24 h). Endothelin-1 (10-7 M) increased the total mass of protein and the incorporation of [14C] phenylalanine into protein to 26% and 25% greater (P

Evidence for two endothelin Et(A) receptor subtypes in rabbit arteriolar smooth muscle.

1. Effects of endothelin-1 (Et-1) were studied on membrane currents in choroidal arteriolar smooth muscle by using perforated patch-clamp recordings. 2. Et-1 (10 nM) activated oscillatory Ca(2+)-activated Cl(-)-currents (I(Cl(Ca))) which could not be reversed by washing out. 3. Currents through L-type Ca(2+) channels were resolved in a divalent free medium (I(Ca(L)Na)). Et-1 reduced I(Ca(L)Na) by 75 +/- 7% within 30 s and this effect faded over 5 min, when the depression remained constant. On washing out Et-1, I(Ca(L)Na) almost completely recovered within 10 s. 4. BQ123 (1 microM), a peptide Et(A) receptor blocker, prevented the activation of I(Cl(Ca)), but failed to inhibit I(Cl(Ca)) transients once they had been initiated. In contrast, BQ123 not only prevented but also reversed the inhibition of I(Ca(L)Na) by Et-1. BQ788 (1 microM), an Et(B) receptor antagonist, did not prevent the activation of I(Cl(Ca)) or the inhibition of I(Ca(L)Na) by Et-1. 5. ABT-627 (10 nM), a non-peptide Et(A) receptor antagonist also blocked the activation of I(Cl(Ca)). However, on I(Ca(L)Na), ABT-627 (10 nM) mimicked the action of Et-1 an effect blocked by BQ123 suggesting that ABT-627 acted as an agonist. 6. The data are consistent with choroidal arteriolar smooth muscle cells having two types of Et(A) receptor, one where BQ123 is an antagonist and ABT-627 an agonist, where ligands dissociate freely and this receptor is coupled to inhibition of L-type Ca(2+) channels. In the other, BQ123 and ABT-627 are both antagonists and with Et-1 the receptor converts to a high affinity state producing the classical irreversible activation I(Cl(Ca)).