Logique floue Appliquée à la gestion à long terme des ressources en eau

Dans le contexte de la rareté des ressources en eau, une approche globale de la gestion à long terme d'un système de stockage/transfert/distribution d'eau est proposée. L'objectif principal de la gestion d'un tel type de système est de gérer les réserves et les délestages de manière à minimiser les écarts entre offre et demande, ceci à partir d'une prédiction de la demande et des apports.Ainsi, on propose une approche à horizon glissant et surtout une procédure d'adaptation des pondérations du critère fondée sur la logique floue. Cette notion d'adaptation du critère parait tout à fait judicieuse quand on connaît la difficulté de définir les pondérations de tels problèmes d'optimisation et son influence sur la pertinence de la solution obtenue. On vérifie ici l'apport essentiel de la logique floue qui permet d'appréhender finement les enjeux en présence dans la gestion de long terme du système stockage/transfert/distribution d'eau. Le problème de gestion à long terme est résolu par une heuristique améliorée utilisant la programmation linéaire et la programmation dynamique pour réduire les effets de la discrétisation spatiale qui est si limitative dans ce contexte.L'approche de gestion proposée est effectivement appliquée à un cas d'étude qui permet de mettre en évidence sa relative simplicité de mise en œuvre.Since the origins of history, irrigation of agricultural lands has been reported to be an activity of great concern for many human societies. At the beginning, natural irrigation systems such as the Nile River flowing through the sands of Egypt have provided to neighbouring populations some amenities in their hard life. However irregular cycles of floods and droughts were a serious impediment to permanent settlements and to a continuous improvement of life conditions. Consequently human ingenuity has been continuously challenged by the development of new ways and means to master water resource system (WRS).During the last century, improved civil engineering techniques and the development of digital control systems and techniques have dramatically increased the power of human societies over their water resources. However many problems, which received some attention in the past, now require new approaches, given the steady increase in water demand and the introduction of environmental conservation considerations. Today, intelligent systems techniques appear to be able to give some insight in this direction by improving the efficiency of the different decision steps involved in the management and control of such systems. This paper focuses on the problem of the long-term management of a water resource system composed of a network of dams and river reaches. This system is viewed as a hybrid dynamic system, called here a storage/transfer/distribution system. The main long-term management objective of such a system is to manage reserves and releases so as to minimise the deficit between supply and demand by taking into account predictions of demand and contributions.Thus, in the present context of water resource scarcity, a complete approach for long-term management of a storage/transfer/distribution system is proposed. To take into account major uncertainties related to the operations of this kind of system, a sliding horizon approach (it consists of readjusting each week the release plan over the whole coming year, according to the present reserves, the most recent long-term demand estimation and the programmed release for the next week). In addition, an adaptation procedure of weighting parameters of the minimisation criterion based on fuzzy logic is implemented. The definition of an optimisation objective function is in this case a very intricate question since it involves competition, uncertainty and geographical dispersion. However, it is crucial to guarantee the quality of long-term management. This is why Fuzzy Logic is used as a particularly appropriate means to refine on-line the formulation of the objective function of the recurrent optimisation problem. Fuzzy Logic is also shown to be very useful in defining what is at stake in the long-term management. This criterion adaptation concept seems judicious, in view of the difficulty of defining the weighting parameters of such optimisation problems and their influence on the relevant solution obtained.The long-term management problem is solved with improved heuristics using linear programming and dynamic programming in order to reduce the effects of spatial discretisation, which is so restrictive in this context. The suggested approach is applied to a case study, which highlights its relative simplicity of implementation

Estimating the burden of malaria in Senegal : Bayesian zero-inflated binomial geostatistical modeling of the MIS 2008 data

The Research Center for Human Development in Dakar (CRDH) with the technical assistance of ICF Macro and the National Malaria Control Programme (NMCP) conducted in 2008/2009 the Senegal Malaria Indicator Survey (SMIS), the first nationally representative household survey collecting parasitological data and malaria-related indicators. In this paper, we present spatially explicit parasitaemia risk estimates and number of infected children below 5 years. Geostatistical Zero-Inflated Binomial models (ZIB) were developed to take into account the large number of zero-prevalence survey locations (70%) in the data. Bayesian variable selection methods were incorporated within a geostatistical framework in order to choose the best set of environmental and climatic covariates associated with the parasitaemia risk. Model validation confirmed that the ZIB model had a better predictive ability than the standard Binomial analogue. Markov chain Monte Carlo (MCMC) methods were used for inference. Several insecticide treated nets (ITN) coverage indicators were calculated to assess the effectiveness of interventions. After adjusting for climatic and socio-economic factors, the presence of at least one ITN per every two household members and living in urban areas reduced the odds of parasitaemia by 86% and 81% respectively. Posterior estimates of the ORs related to the wealth index show a decreasing trend with the quintiles. Infection odds appear to be increasing with age. The population-adjusted prevalence ranges from 0.12% in Thille-Boubacar to 13.1% in Dabo. Tambacounda has the highest population-adjusted predicted prevalence (8.08%) whereas the region with the highest estimated number of infected children under the age of 5 years is Kolda (13940). The contemporary map and estimates of malaria burden identify the priority areas for future control interventions and provide baseline information for monitoring and evaluation. Zero-Inflated formulations are more appropriate in modeling sparse geostatistical survey data, expected to arise more frequently as malaria research is focused on eliminatio

Novelty Induces Behavioural And Glucocorticoid Responses In A Songbird Artificially Selected For Divergent Personalities

Stress physiology is thought to contribute to individual differences in behaviour. In part this reflects the fact that canonical personality measures consist of responses to challenges, including novel objects and environments. Exposure to novelty is typically assumed to induce a moderate increase in glucocorticoids (CORT), although this has rarely been tested. We tested this assumption using great tits, Parus major, selected for divergent personalities (bold-fast and shy-slow explorers), predicting that the shy birds would exhibit higher CORT following exposure to a novel object. We also scored behavioural responses to the novel object, predicting that bold birds would more frequently approach the novel object and exhibit more abnormal repetitive behaviours. We found that the presence of a novel object did induce a moderate CORT response, but selection lines did not differ in the magnitude of this response. Furthermore, although both selection lines showed a robust CORT elevation to a subsequent restraint stressor, the CORT response was stronger in bold birds and this effect was specific to novel object exposure. Shy birds showed a strong positive phenotypic correlation between CORT concentrations following the novel object exposure and the subsequent restraint stress. Behaviourally, the selection lines differed in their response during novel object exposure: as predicted, bold birds more frequently approached the novel object and shy birds more strongly decreased overall locomotion during the novel object trial, but birds from both selection lines showed significant and similar frequencies of abnormal repetitive behaviours during novel object exposure. Our findings support the hypothesis that personality emerges as a result of correlated selection on behaviour and underlying endocrine mechanisms and suggest that the relationship between endocrine stress physiology and personality is context dependent

Caracterisation agromorphologique, chimique et biochimique des noix brutes de trois provenances d’anacardiers (Anacardium occidentale L.) au Sud du Senegal

La sécurité alimentaire est l’une des préoccupations majeures des hommes dans le monde. Pour l’atteindre, les populations rurales tirent une grande partie de leurs alimentations dans les Produits Forestiers Non Ligneux. Anacardium occidentale L., une espèce agroforestière très prisée n’est pas en reste. Cependant, des études sur la valeur alimentaire et nutritionnelle de ses noix sont limitées et restent parcellaires. L’objectif de cette recherche est d’évaluer les teneurs en éléments nutritifs des noix brutes de Anacardium occidentale L. collectées à Ziguinchor, Sédhiou et Kolda. Pour ce faire, dans chaque zone, trois kilogrammes de noix ont été prélevées de manière aléatoire dans différents lieux de stockage. Puis les mensurations ont porté sur 450 noix par provenance. Les noix ont été ensuite décortiquées puis soumises à une analyse minérale (chimique et biochimique). Une analyse uni et multivariée a été effectuée à l’aide de XLSTAT 6.0. L’analyse a montré l’existence d’une variabilité des caractéristiques entre les provenances. Une corrélation forte, significative mais négative a été détectée entre le poids des amandes et la cellulose brute, ce qui signifierait que les amandes de petite taille sont plus sucrées. A travers cette étude, plusieurs possibilités s’offrent aux différents acteurs de la chaine de valeur anacarde. English title: Agromorphological, chemical and biochemical characterization of <I>Anacardium occidentale L.</I> in Sud Senegal Food security is one of the major concerns of people around the world. To achieve this, rural populations derive a large part of their food from Non-Wood Forest Products. Anacardium occidentale L., a highly prized agroforestry species, is not to be outdone. However, studies on the food and nutritional value of its nuts are limited and remain fragmented. The objective of this research is to evaluate the nutrient content of raw nuts of Anacardium occidentale L. collected in Ziguinchor, Sédhiou and Kolda. To do this, in each area, three kilograms of nuts were taken at random from  different storage locations. Then the measurements were carried out on 450 nuts per provenance. The nuts were then shelled and then subjected to mineral analysis (chemical and biochemical). Univariate and multivariate analysis was performed using XLSTAT 6.0. The analysis showed the  existence of variability in characteristics between provenances. A strong, significant but negative correlation was detected between the weight of the almonds and the crude fiber, which would mean that the small almonds are sweeter. Through this study, several possibilities are available to the various players in the cashew value chain

Hadamard Regularization

Motivated by the problem of the dynamics of point-particles in high post-Newtonian (e.g. 3PN) approximations of general relativity, we consider a certain class of functions which are smooth except at some isolated points around which they admit a power-like singular expansion. We review the concepts of (i) Hadamard ``partie finie'' of such functions at the location of singular points, (ii) the partie finie of their divergent integral. We present and investigate different expressions, useful in applications, for the latter partie finie. To each singular function, we associate a partie-finie (Pf) pseudo-function. The multiplication of pseudo-functions is defined by the ordinary (pointwise) product. We construct a delta-pseudo-function on the class of singular functions, which reduces to the usual notion of Dirac distribution when applied on smooth functions with compact support. We introduce and analyse a new derivative operator acting on pseudo-functions, and generalizing, in this context, the Schwartz distributional derivative. This operator is uniquely defined up to an arbitrary numerical constant. Time derivatives and partial derivatives with respect to the singular points are also investigated. In the course of the paper, all the formulas needed in the application to the physical problem are derived.Comment: 50 pages, to appear in Journal of Mathematical Physic

Efficacy and tolerability of four antimalarial combinations in the treatment of uncomplicated Plasmodium falciparum malaria in Senegal

<p>Abstract</p> <p>Background</p> <p>In view of the high level of chloroquine resistance in many countries, WHO has recommended the use of combination therapy with artemisinin derivatives in the treatment of uncomplicated malaria due to <it>Plasmodium falciparum</it>. Four antimalarial drug combinations, artesunate plus amodiaquine (Arsucam^®), artesunate plus mefloquine (Artequin^®), artemether plus lumefantrine (Coartem^®; four doses and six doses), and amodiaquine plus sulphadoxine-pyrimethamine, were studied in five health districts in Senegal.</p> <p>Methods</p> <p>This is a descriptive, analytical, open, randomized study to evaluate the efficacy and tolerability of these four antimalarial combinations in the treatment of uncomplicated falciparum malaria using the 2002 WHO protocol.</p> <p>Results</p> <p>All drug combinations demonstrated good efficacy. On day 28, all combinations resulted in an excellent clinical and parasitological response rate of 100% after correction for PCR results, except for the four-dose artemether-lumefantrine regimen (96.4%). Follow-up of approximately 10% of each treatment group on day 42 demonstrated an efficacy of 100%.</p> <p>The combinations were well tolerated clinically and biologically. No unexpected side-effect was observed and all side-effects disappeared at the end of treatment. No serious side-effect requiring premature termination of treatment was observed.</p> <p>Conclusion</p> <p>The four combinations are effective and well-tolerated.</p

Analyse et prevention des troubles du cycle reproductif chez les caprins en region semi-aride dans le Nordeste bresilien.

Une enquete ecopathologique sur les avortements caprins en elevage traditionnel dans le nord-est du Bresil a permis de mettre en evidence une succession de troubles du cycle reproductif affectant le rendement zootechnique. L'analyse du cycle a fourni les elements necessaires a la formulation de mesures de prevention de ces troubles. Il s'agit, en manipulant le cycle reproductif, de realiser une meilleure adequation entre l'offre alimentaire, tres saisonnee, et la période de mises bas. Certaines mesures de conduite de la mise bas devraient entrainer une diminution importante de la mortalite des jeunes

Network dynamics with a nested node set: sociability in seven villages in Senegal

We propose two complementary ways to deal with a nesting structure in the node set of a network—such a structure may be called a multilevel network, with a node set consisting of several groups. First, within‐group ties are distinguished from between‐group ties by considering them as two distinct but interrelated networks. Second, effects of nodal variables are differentiated according to the levels of the nesting structure, to prevent ecological fallacies. This is elaborated in a study of two repeated observations of a sociability network in seven villages in Senegal, analyzed using the Stochastic Actor‐oriented Model

Lorentzian regularization and the problem of point-like particles in general relativity

The two purposes of the paper are (1) to present a regularization of the self-field of point-like particles, based on Hadamard's concept of ``partie finie'', that permits in principle to maintain the Lorentz covariance of a relativistic field theory, (2) to use this regularization for defining a model of stress-energy tensor that describes point-particles in post-Newtonian expansions (e.g. 3PN) of general relativity. We consider specifically the case of a system of two point-particles. We first perform a Lorentz transformation of the system's variables which carries one of the particles to its rest frame, next implement the Hadamard regularization within that frame, and finally come back to the original variables with the help of the inverse Lorentz transformation. The Lorentzian regularization is defined in this way up to any order in the relativistic parameter 1/c^2. Following a previous work of ours, we then construct the delta-pseudo-functions associated with this regularization. Using an action principle, we derive the stress-energy tensor, made of delta-pseudo-functions, of point-like particles. The equations of motion take the same form as the geodesic equations of test particles on a fixed background, but the role of the background is now played by the regularized metric.Comment: 34 pages, to appear in J. Math. Phy

Canonical formulation of self-gravitating spinning-object systems

Based on the Arnowitt-Deser-Misner (ADM) canonical formulation of general relativity, a canonical formulation of gravitationally interacting classical spinning-object systems is given to linear order in spin. The constructed position, linear momentum and spin variables fulfill standard Poisson bracket relations. A spatially symmetric time gauge for the tetrad field is introduced. The achieved formulation is of fully reduced form without unresolved constraints, supplementary, gauge, or coordinate conditions. The canonical field momentum is not related to the extrinsic curvature of spacelike hypersurfaces in standard ADM form. A new reduction of the tetrad degrees of freedom to the Einstein form of the metric field is suggested.Comment: 6 pages. v2: extended version; identical to the published one. v3: corrected misprints in (24) and (39); improved notation; added note regarding a further reference