39 research outputs found

    Construction participative d’un modèle régional pour l’évaluation de la demande en eau agricole: un exemple dans le bassin de la Drôme

    Get PDF
    International audienceLa " gestion intégrée des ressources en eau " tente de rendre compte du fonctionnement d’" hydro-systèmes " qui rassemblent un ensemble de ressources et d’usages de l’eau en interaction au sein d’un territoire, qui lui-même recouvre diverses unités administratives ou politiques. Pour mettre en place cette gestion intégrée, certains pays ont opté pour une décentralisation : la gestion de l’eau est alors confiée à des organisations de bassin au sein desquels siègent des porte-parole des différents intérêts en jeu. Ces organisations soulignent le peu de support pour favoriser la concertation. Les outils disponibles mettent l’accent sur les processus biophysiques, mais proposent une représentation très simplifiée des usages notamment agricoles. Ces usages sont non seulement liés aux disponibilités en eau et à ses conditions d’accès, mais aussi au contexte technologique, économique, et institutionnel dans lequel les agriculteurs évoluent. Pour favoriser la concertation, nous proposons de construire avec les acteurs locaux une représentation du système dans lequel ils agissent, touchant à la fois aux aspects techniques, et économiques. L’objectif est de représenter les interactions entre ressource et usages (notamment agricoles), et d’évaluer les conséquences de scénarios imaginés à l’échelle du territoire. Ce modèle régional comprend donc (i) une caractérisation hydrologique simplifiée qui permet d’évaluer en entrée les disponibilités initiales de la ressource et de mesurer les impacts des prélèvements, (ii) un modèle bio-physique PILOT qui permet d’évaluer les consommations d’eau, et les rendements selon les pratiques agricoles et les conditions agroclimatiques, et (iii) un modèle technico-économique qui rend compte des choix techniques des agriculteurs et de leurs conséquences en termes économiques. Le modèle technicoéconomique des activités agricoles à l’échelle régionale s’appuie sur une typologie des exploitations et des ateliers de productions agricoles. Dans ce modèle, (i) les activités agricoles à l’échelle régionale sont la somme pondérée des activités des exploitations types (les pondérations correspondent aux effectifs d’exploitations), et (ii) les activités d’une exploitation type sont la somme pondérée d’ateliers de production types (les pondérations correspondent aux dimensions des ateliers). Cette structure permet d’agréger à l’échelle régionale les impacts des activités et de désagréger à l’échelle des exploitations et de leurs activités les conséquences de mesures globales. La construction participative du modèle régional s’appuie sur la mise en place dès le démarrage de l’étude d’un " groupe de pilotage ", composé des représentants des acteurs locaux. Ce groupe de pilotage participe à la modélisation en fournissant les données nécessaires et en validant chaque étape de la construction. Le modèle, construit et validé par Colloque - 13th IWRA World water congress, 1-4 september 2008, Montpellier tous les acteurs, peut alors contribuer à aider les décideurs locaux ou régionaux à élaborer des scénarios raisonnés pour définir des stratégies de gestion intégrée et durable de l’eau. Nous avons mis en oeuvre cette démarche dans le bassin de la Drôme dans le cadre du programme APPEAU financé par l’Agence Nationale de la Recherche (programme " Agriculture et Développement Durable "), et en nous appuyant sur les travaux du programme MIPAIS financé par l’Union Européenne (programme Interreg III Medoc). / The "integrated management of water resources" tries to convey the functioning of the "hydro-systems" which brings together a group of resources and uses of water. This group of resources and uses interacts within a territory, which itself includes various administrative or political units. In order to develop this integrated management, some countries have chosen decentralization: water management is then given to basin institutions within which representatives of the various key interests sit. These institutions emphasize the poor support they get to encourage the dialogue. Available tools emphasize biophysical process but provide a very simplified representation of uses, and particularly of farm uses. These uses are not only linked to water availabilities and to its conditions of access, but also to the technological, economic, and institutional background in which the farmers operate. With the local stakeholders, we suggest to build a model of the system in which they act. At the same time, this model includes the technical, economic, and environmental sides. Therefore, this regional model includes (i) a hydrological model, which enables to assess as input the initial resource availabilities and to measure the impacts of withdrawals, (ii) a biophysical model which enables to assess crop water needs, yields and environmental impacts according to agricultural practices and agro-climatic conditions, and (iii) a technical and economic model which conveys the technical choices of farmers and theirs economic consequences. The construction of the hydrological and biophysical models can be limited to the parameterization of pre-existing models. The technical and economic model of farm activities at the regional scale relies on a typology of farms and of farm production units; its structure has been designed to enable an aggregation and a desegregation of the results between various scales, which provides a detailed analysis of the studied scenarios. The participative construction of the regional model relies on the creation, from the start of the study, of a “steering group” compound of the representatives of local stakeholders. This steering group takes part in the modelling by supplying the necessary data and by validating each stage of the model construction. The model, build and validated by all the stakeholders, can then contribute to help the local or regional decision-makers to develop reasoned scenarios in order to define strategies of integrated and sustainable water management. We have implemented this approach in the Drôme basin within the framework of the APPEAU project funded by the "Agriculture et Développement Durable" program of the French National Research Agency, and by relying on the works of the MIPAIS project funded by the Programme Interreg III Medoc of the European Union. This paper presents the first results obtained

    Un outil de simulation adapté à la gestion des ressources en eau du territoire dans le cadre d’une démarche participative

    Get PDF
    National audienceThis paper presents a simulation tool adapted to water resources management on a territorial scale, as part of a participatory process. This tool combines the PILOTE-TER crop model and the Olympe technico-economical simulator. PILOTE-TER links the crop model Pilote developed by Irstea with a database managed through a graphical interface. It makes possible to use the Pilote model to evaluate the water demand and the crop yield at the scale of the field, the farm and the territory. The parameters of the model come from the results of experiments performed by Irstea. PILOTE-TER is linked to the technico-economic simulator Olympe (from INRA) to produce economical indicators. These tools are used for a territorial representation of agriculture build with local stakeholders, allowing the comparison of several scenarios (based on economical, policy or climate changes).Cet article présente un outil de simulation adapté à la gestion de ressources en eau à l’échelle d’un territoire dans le cadre de démarches participatives. Cet outil associe un modèle de culture, Pilote Ter, et le simulateur technico-économique Olympe. Pilote Ter intègre le modèle de culture Pilote développé par Irstea et un système de base de données géré à partir d’une interface graphique. Il permet une utilisation territorialisée du modèle de culture Pilote pour évaluer la demande en eau agricole et les rendements des cultures à l’échelle de la parcelle, de l’exploitation agricole et du territoire. Le paramétrage du modèle s’appuie sur les résultats des expérimentations menées par Irstea. Pilote Ter est couplé au simulateur technico-économique Olympe (INRA) pour produire des indicateurs économiques. Ces deux logiciels sont le support d’une représentation de l’agriculture du territoire co-construite avec les acteurs locaux permettant l’étude de scénarios économiques, réglementaires ou climatiques

    Single photon generation by pulsed excitation of a single dipole

    Get PDF
    The fluorescence of a single dipole excited by an intense light pulse can lead to the generation of another light pulse containing a single photon. The influence of the duration and energy of the excitation pulse on the number of photons in the fluorescence pulse is studied. The case of a two-level dipole with strongly damped coherences is considered. The presence of a metastable state leading to shelving is also investigated.Comment: 17 pages, 4 figures, submitted to PR

    The Crc global regulator binds to an unpaired A-rich motif at the Pseudomonas putida alkS mRNA coding sequence and inhibits translation initiation

    Get PDF
    Crc is a key global translational regulator in Pseudomonads that orchestrates the hierarchy of induction of several catabolic pathways for amino acids, sugars, hydrocarbons or aromatic compounds. In the presence of amino acids, which are preferred carbon sources, Crc inhibits translation of the Pseudomonas putida alkS and benR mRNAs, which code for transcriptional regulators of genes required to assimilate alkanes (hydrocarbons) and benzoate (an aromatic compound), respectively. Crc binds to the 5′-end of these mRNAs, but the sequence and/or structure recognized, and the way in which it inhibits translation, were unknown. We have determined the secondary structure of the alkS mRNA 5′-end through its sensitivity to several ribonucleases and chemical reagents. Footprinting and band-shift assays using variant alkS mRNAs have shown that Crc specifically binds to a short unpaired A-rich sequence located adjacent to the alkS AUG start codon. This interaction is stable enough to prevent formation of the translational initiation complex. A similar Crc-binding site was localized at benR mRNA, upstream of the Shine–Dalgarno sequence. This allowed predicting binding sites at other Crc-regulated genes, deriving a consensus sequence that will help to validate new Crc targets and to discriminate between direct and indirect effects of this regulator

    Effects of the Training Dataset Characteristics on the Performance of Nine Species Distribution Models: Application to Diabrotica virgifera virgifera

    Get PDF
    Many distribution models developed to predict the presence/absence of invasive alien species need to be fitted to a training dataset before practical use. The training dataset is characterized by the number of recorded presences/absences and by their geographical locations. The aim of this paper is to study the effect of the training dataset characteristics on model performance and to compare the relative importance of three factors influencing model predictive capability; size of training dataset, stage of the biological invasion, and choice of input variables. Nine models were assessed for their ability to predict the distribution of the western corn rootworm, Diabrotica virgifera virgifera, a major pest of corn in North America that has recently invaded Europe. Twenty-six training datasets of various sizes (from 10 to 428 presence records) corresponding to two different stages of invasion (1955 and 1980) and three sets of input bioclimatic variables (19 variables, six variables selected using information on insect biology, and three linear combinations of 19 variables derived from Principal Component Analysis) were considered. The models were fitted to each training dataset in turn and their performance was assessed using independent data from North America and Europe. The models were ranked according to the area under the Receiver Operating Characteristic curve and the likelihood ratio. Model performance was highly sensitive to the geographical area used for calibration; most of the models performed poorly when fitted to a restricted area corresponding to an early stage of the invasion. Our results also showed that Principal Component Analysis was useful in reducing the number of model input variables for the models that performed poorly with 19 input variables. DOMAIN, Environmental Distance, MAXENT, and Envelope Score were the most accurate models but all the models tested in this study led to a substantial rate of mis-classification

    Impact of chronic obstructive pulmonary disease and dyspnoea on clinical outcomes in ticagrelor treated patients undergoing percutaneous coronary intervention in the randomized GLOBAL LEADERS trial

    Get PDF
    AIMS: To evaluate long-term safety and efficacy of ticagrelor monotherapy in patients undergoing percutaneous coronary interventions (PCIs) in relation to chronic obstructive pulmonary disease (COPD) at baseline and the occurrence of dyspnoea reported as adverse event (AE) that may lead to treatment non-adherence. METHODS AND RESULTS: This is a non-prespecified, post hoc analysis of the randomized GLOBAL LEADERS trial (n = 15 991), comparing the experimental strategy of 23-month ticagrelor monotherapy following 1-mo

    Association of the PHACTR1/EDN1 genetic locus with spontaneous coronary artery dissection

    Get PDF
    Background: Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of acute coronary syndromes (ACS) afflicting predominantly younger to middle-aged women. Observational studies have reported a high prevalence of extracoronary vascular anomalies, especially fibromuscular dysplasia (FMD) and a low prevalence of coincidental cases of atherosclerosis. PHACTR1/EDN1 is a genetic risk locus for several vascular diseases, including FMD and coronary artery disease, with the putative causal noncoding variant at the rs9349379 locus acting as a potential enhancer for the endothelin-1 (EDN1) gene. Objectives: This study sought to test the association between the rs9349379 genotype and SCAD. Methods: Results from case control studies from France, United Kingdom, United States, and Australia were analyzed to test the association with SCAD risk, including age at first event, pregnancy-associated SCAD (P-SCAD), and recurrent SCAD. Results: The previously reported risk allele for FMD (rs9349379-A) was associated with a higher risk of SCAD in all studies. In a meta-analysis of 1,055 SCAD patients and 7,190 controls, the odds ratio (OR) was 1.67 (95% confidence interval [CI]: 1.50 to 1.86) per copy of rs9349379-A. In a subset of 491 SCAD patients, the OR estimate was found to be higher for the association with SCAD in patients without FMD (OR: 1.89; 95% CI: 1.53 to 2.33) than in SCAD cases with FMD (OR: 1.60; 95% CI: 1.28 to 1.99). There was no effect of genotype on age at first event, P-SCAD, or recurrence. Conclusions: The first genetic risk factor for SCAD was identified in the largest study conducted to date for this condition. This genetic link may contribute to the clinical overlap between SCAD and FMD

    From Sea to Sea: Canada's Three Oceans of Biodiversity

    Get PDF
    Evaluating and understanding biodiversity in marine ecosystems are both necessary and challenging for conservation. This paper compiles and summarizes current knowledge of the diversity of marine taxa in Canada's three oceans while recognizing that this compilation is incomplete and will change in the future. That Canada has the longest coastline in the world and incorporates distinctly different biogeographic provinces and ecoregions (e.g., temperate through ice-covered areas) constrains this analysis. The taxonomic groups presented here include microbes, phytoplankton, macroalgae, zooplankton, benthic infauna, fishes, and marine mammals. The minimum number of species or taxa compiled here is 15,988 for the three Canadian oceans. However, this number clearly underestimates in several ways the total number of taxa present. First, there are significant gaps in the published literature. Second, the diversity of many habitats has not been compiled for all taxonomic groups (e.g., intertidal rocky shores, deep sea), and data compilations are based on short-term, directed research programs or longer-term monitoring activities with limited spatial resolution. Third, the biodiversity of large organisms is well known, but this is not true of smaller organisms. Finally, the greatest constraint on this summary is the willingness and capacity of those who collected the data to make it available to those interested in biodiversity meta-analyses. Confirmation of identities and intercomparison of studies are also constrained by the disturbing rate of decline in the number of taxonomists and systematists specializing on marine taxa in Canada. This decline is mostly the result of retirements of current specialists and to a lack of training and employment opportunities for new ones. Considering the difficulties encountered in compiling an overview of biogeographic data and the diversity of species or taxa in Canada's three oceans, this synthesis is intended to serve as a biodiversity baseline for a new program on marine biodiversity, the Canadian Healthy Ocean Network. A major effort needs to be undertaken to establish a complete baseline of Canadian marine biodiversity of all taxonomic groups, especially if we are to understand and conserve this part of Canada's natural heritage

    Rapid identification of causal mutations in tomato EMS populations via mapping-by-sequencing

    Get PDF
    The tomato is the model species of choice for fleshy fruit development and for the Solanaceae family. Ethyl methanesulfonate (EMS) mutants of tomato have already proven their utility for analysis of gene function in plants, leading to improved breeding stocks and superior tomato varieties. However, until recently, the identification of causal mutations that underlie particular phenotypes has been a very lengthy task that many laboratories could not afford because of spatial and technical limitations. Here, we describe a simple protocol for identifying causal mutations in tomato using a mapping-by-sequencing strategy. Plants displaying phenotypes of interest are first isolated by screening an EMS mutant collection generated in the miniature cultivar Micro-Tom. A recombinant F2 population is then produced by crossing the mutant with a wild-type (WT; non-mutagenized) genotype, and F2 segregants displaying the same phenotype are subsequently pooled. Finally, whole-genome sequencing and analysis of allele distributions in the pools allow for the identification of the causal mutation. The whole process, from the isolation of the tomato mutant to the identification of the causal mutation, takes 6-12 months. This strategy overcomes many previous limitations, is simple to use and can be applied in most laboratories with limited facilities for plant culture and genotyping

    Modelling human choices: MADeM and decision‑making

    Get PDF
    Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)
    corecore