Aménagements hydro-agricoles et santé (vallée du fleuve Sénégal)

Près de 1 500 personnes résidant dans les villages rattachés au périmètre irrigué MO 6bis (périmètre de Diomandou, département de Podor) ont fait l'objet de prélèvements d'urine et/ou de selle afin de déterminer la prévalence de la bilharziose urinaire, de la bilharziose intestinale ainsi que des autres parasitoses entériques. Chez les riverains du périmètre, 1 295 urines ont été examinées, parmi lesquelles sept contenaient des oeufs viables de #Schistosoma haematobium$, ce qui représente un taux de prévalence de 0,5$, ce qui correspond à un indice d'infestation de 0,1%. Il s'agissait là aussi d'un individu dont la contamination avait eu lieu en dehors de la zone d'étude. #Eschirichia coli$est la parasite entérique le plus répandu avec 17,2$, #Strongyloïdes stercoralis, #Ascaris lumbricoïdes et #Trichiuris trichiura$ sont rares et ne concernent qu'un peu moins de 2% des sujets examinés. Ces résultats démontrent l'absence, pour l'instant tout au moins, de foyers de transmission des bilharzioses dans les villages du périmètre de Diomandou. Le risque d'apparition de ces maladies est cependant important et dépend à la fois de l'évolution des infrastructures et de l'éventuelle apparition d'hôtes intermédiaires encore absent du réseau hydrographique de ce périmètre mis en place récemment. (Résumé d'auteur

Finite-size scaling analysis of the distributions of pseudo-critical temperatures in spin glasses

Using the results of large scale numerical simulations we study the probability distribution of the pseudo critical temperature for the three-dimensional Edwards-Anderson Ising spin glass and for the fully connected Sherrington-Kirkpatrick model. We find that the behavior of our data is nicely described by straightforward finite-size scaling relations.Comment: 23 pages, 9 figures. Version accepted for publication in J. Stat. Mec

Joint distribution of the first and second eigenvalues at the soft edge of unitary ensembles

The density function for the joint distribution of the first and second eigenvalues at the soft edge of unitary ensembles is found in terms of a Painlev\'e II transcendent and its associated isomonodromic system. As a corollary, the density function for the spacing between these two eigenvalues is similarly characterized.The particular solution of Painlev\'e II that arises is a double shifted B\"acklund transformation of the Hasting-McLeod solution, which applies in the case of the distribution of the largest eigenvalue at the soft edge. Our deductions are made by employing the hard-to-soft edge transitions to existing results for the joint distribution of the first and second eigenvalue at the hard edge \cite{FW_2007}. In addition recursions under $a \mapsto a+1$ of quantities specifying the latter are obtained. A Fredholm determinant type characterisation is used to provide accurate numerics for the distribution of the spacing between the two largest eigenvalues.Comment: 26 pages, 1 Figure, 2 Table

Knowledge formalization in experience feedback processes : an ontology-based approach

Because of the current trend of integration and interoperability of industrial systems, their size and complexity continue to grow making it more difficult to analyze, to understand and to solve the problems that happen in their organizations. Continuous improvement methodologies are powerful tools in order to understand and to solve problems, to control the effects of changes and finally to capitalize knowledge about changes and improvements. These tools involve suitably represent knowledge relating to the concerned system. Consequently, knowledge management (KM) is an increasingly important source of competitive advantage for organizations. Particularly, the capitalization and sharing of knowledge resulting from experience feedback are elements which play an essential role in the continuous improvement of industrial activities. In this paper, the contribution deals with semantic interoperability and relates to the structuring and the formalization of an experience feedback (EF) process aiming at transforming information or understanding gained by experience into explicit knowledge. The reuse of such knowledge has proved to have significant impact on achieving themissions of companies. However, the means of describing the knowledge objects of an experience generally remain informal. Based on an experience feedback process model and conceptual graphs, this paper takes domain ontology as a framework for the clarification of explicit knowledge and know-how, the aim of which is to get lessons learned descriptions that are significant, correct and applicable

Les fourmis (Hymenoptera, Formicidae) de l’enclos d’acclimatation de Katané de la réserve de faune du Ferlo nord (Sénégal)

Les fourmis (Hymenoptera, Formicidae), de par leur biomasse, et leur diversité spécifique, jouent un rôle fondamental dans les écosystèmes terrestres tropicaux. Néanmoins, elles sont très peu étudiées et mal connues au Sénégal. Pour contribuer à combler cette lacune nous avons étudié le peuplement des fourmis de l’enclos d’acclimatation de Katané, un site se trouvant dans la Réserve de Faune du Ferlo Nord en zone de savane sahélienne (région de Matam, Sénégal). Les fourmis ont été échantillonnées à l’aide de pièges à fosse et par la chasse à vue. La richesse spécifique (S) est de 21 espèces. Les espèces les plus remarquables par leur abondance et leur distribution sont Crematogaster senegalensis, Monomorium areniphilum, Trichomyrmex abyssinicus, Monomorium bicolor, Pheidole andrieui, Brachyponera sennaarensis, Tetramorium angulinode papyri et Tetramorium sericeiventre. Elles appartiennent toutes à la sous-famille des Myrmicinae sauf B. sennaarensis qui est de la sous-famille des Ponerinae. L’indice de fourragement (9,79), l’indice de Shannon (0,95), l’indice d’équitabilité de Piélou (0,77), l’indice de Simpson (0,14) et l’indice de diversité de Simpson (0,86) peuvent être utilisés comme référentiels pour le suivi de l’évolution des habitats de l’enclos et pour les études de l’état de dégradation des habitats dans le Ferlo en général.© 2016 International Formulae Group. All rights reserved.Mots clés: Fourmis, écosystèmes, diversité, abondance, Ferlo nord, SénégalEnglish Title: Ants (Hymenoptera, Formicidae) of the acclimatization enclosure of Katane in the north Ferlo wildlife reserve (Senegal)English AbstractAnts (Hymenoptera, Formicidae), by their biomass and species diversity, play a fundamental role in the terrestrial ecosystems of the tropical area. Nevertheless, they are very little studied and poorly known in Senegal. To fill this gap we have chosen to study them in the acclimatization enclosure of Katane in the north Ferlo Reserve Wildlife situated in the Sahel savanna in Matam region (Senegal). They were sampled using pitfall traps and hand collecting. Species richness (S) is 21 species. The most remarkable for their abundances and distributions are Crematogaster senegalensis, Monomorium areniphilum, Trichomyrmex abyssinicus, Monomorium bicolor, Pheidole andrieui, Brachyponera sennaarensis, Tetramorium angulinode papyri and Tetramorium sericeiventre. They all belong to the subfamily Myrmicinae except B. sennaarensis which belongs to the subfamily Ponerinae. The foraging index (9.79), the Shannon index (0.95), the index of Pielou equitability (0.77), the Simpson index (0.14) and the Simpson's index diversity (0.86) can be used as reference for monitoring the biotopes evolution in the enclosure of Katané and for the studies of land degradation in the Ferlo in general.© 2016 International Formulae Group. All rights reserved.Keywords: Ants, ecosystems, diversity, abundance, northern Ferlo, Senega

Avantages des biodigesteurs sur le bois de chauffe dans les élevages laitiers à Kaolack (Sénégal)

Le déficit énergétique constitue une contrainte à l’épanouissement des ménages ruraux notamment, au niveau de l’énergie de cuisson. Les femmes utilisent le bois de chauffe pour les besoins énergétiques de la cuisson mais aussi, pour la pasteurisation du lait. Cette étude met en évidence les avantages de l’utilisation des biodigesteurs sur le bois de chauffe dans les élevages laitiers à Kaolack (Sénégal). Cent seize ménages ont été enquêtés dont 58 détenteurs de biodigesteurs. Les résultats montrent que les ménages possédant un biodigesteur avaient plus de temps pour se consacrer à des activités rémunératrices ou pour le bien être de la famille avec un tiers (32,75 %) qui mettent moins de 2 h par jour pour la recherche du bois et 2 h pour la cuisson d’un repas contre (67,25 %) de ménages sans biodigesteurs qui y consacraient 2 à 6 h par jour et plus de 3 h pour la cuisson d’un repas. Plus du quart (25,86 %) des ménages avec biodigesteurs utilisaient le biogaz comme source d’éclairage. De même, 36,20 % préparent les repas et pasteurisent le lait avec le biogaz. Il est également constaté une réduction de la fréquence des pathologies respiratoires et oculaires mais aussi des dépenses pour l’achat de combustible et de compost.Mots clés: Biogaz ; bois ; élevages laitiers ; économie des ménages ; Kaolack ; Sénégal Biodigester benefits on wood heating in dairy farming of Kaolack (Senegal)The energy deficit is a major constraint to the development of rural house holds including at cooking energy. Women use firewood for cooking energy needs but also for the pasteurization of milk. This study highlights the benefits of using biogas digesters on firewood in dairy farms in Kaolack (Senegal). One Hundred sixteen households were surveyed of which 58 possessed biodigester.The results show that households with a biodigester had much more time devoted to income-generating activities or for the welfare of the family. One third (32.75 %) of biodigester owners take less than 2 hours per day for wood search and 2 hours for cooking a meal against (67.25 %) of house holds without biodigester who spent 2 to 6 hours per day and put more than 3 hours to cook meal. More than a quarter (25.86 %) of households with biodigester used biogas as a lighting. Similarly, 36.20 % Cook food and pasteurize milk with biogas.The used of biogas expenses for the purchase of fuel as well as the compost for filed fertilization. It seem that biogas utilization reduce the incidence of respiratory and eye diseases.Keywords: Biogas ; wood ; dairy farms ; household economy ; Kaolack ; Senegal

Recent progress in understanding and projecting regional and global mean sea-level change

Considerable progress has been made in understanding the present and future regional and global sea level in the 2 years since the publication of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change. Here, we evaluate how the new results affect the AR5’s assessment of (i) historical sea level rise, including attribution of that rise and implications for the sea level budget, (ii) projections of the components and of total global mean sea level (GMSL), and (iii) projections of regional variability and emergence of the anthropogenic signal. In each of these cases, new work largely provides additional evidence in support of the AR5 assessment, providing greater confidence in those findings. Recent analyses confirm the twentieth century sea level rise, with some analyses showing a slightly smaller rate before 1990 and some a slightly larger value than reported in the AR5. There is now more evidence of an acceleration in the rate of rise. Ongoing ocean heat uptake and associated thermal expansion have continued since 2000, and are consistent with ocean thermal expansion reported in the AR5. A significant amount of heat is being stored deeper in the water column, with a larger rate of heat uptake since 2000 compared to the previous decades and with the largest storage in the Southern Ocean. The first formal detection studies for ocean thermal expansion and glacier mass loss since the AR5 have confirmed the AR5 finding of a significant anthropogenic contribution to sea level rise over the last 50 years. New projections of glacier loss from two regions suggest smaller contributions to GMSL rise from these regions than in studies assessed by the AR5; additional regional studies are required to further assess whether there are broader implications of these results. Mass loss from the Greenland Ice Sheet, primarily as a result of increased surface melting, and from the Antarctic Ice Sheet, primarily as a result of increased ice discharge, has accelerated. The largest estimates of acceleration in mass loss from the two ice sheets for 2003–2013 equal or exceed the acceleration of GMSL rise calculated from the satellite altimeter sea level record over the longer period of 1993–2014. However, when increased mass gain in land water storage and parts of East Antarctica, and decreased mass loss from glaciers in Alaska and some other regions are taken into account, the net acceleration in the ocean mass gain is consistent with the satellite altimeter record. New studies suggest that a marine ice sheet instability (MISI) may have been initiated in parts of the West Antarctic Ice Sheet (WAIS), but that it will affect only a limited number of ice streams in the twenty-first century. New projections of mass loss from the Greenland and Antarctic Ice Sheets by 2100, including a contribution from parts of WAIS undergoing unstable retreat, suggest a contribution that falls largely within the likely range (i.e., two thirds probability) of the AR5. These new results increase confidence in the AR5 likely range, indicating that there is a greater probability that sea level rise by 2100 will lie in this range with a corresponding decrease in the likelihood of an additional contribution of several tens of centimeters above the likely range. In view of the comparatively limited state of knowledge and understanding of rapid ice sheet dynamics, we continue to think that it is not yet possible to make reliable quantitative estimates of future GMSL rise outside the likely range. Projections of twenty-first century GMSL rise published since the AR5 depend on results from expert elicitation, but we have low confidence in conclusions based on these approaches. New work on regional projections and emergence of the anthropogenic signal suggests that the two commonly predicted features of future regional sea level change (the increasing tilt across the Antarctic Circumpolar Current and the dipole in the North Atlantic) are related to regional changes in wind stress and surface heat flux. Moreover, it is expected that sea level change in response to anthropogenic forcing, particularly in regions of relatively low unforced variability such as the low-latitude Atlantic, will be detectable over most of the ocean by 2040. The east-west contrast of sea level trends in the Pacific observed since the early 1990s cannot be satisfactorily accounted for by climate models, nor yet definitively attributed either to unforced variability or forced climate change

Multi-model evaluation of the sensitivity of the global energy budget and hydrological cycle to resolution

This study undertakes a multi-model comparison with the aim to describe and quantify systematic changes of the global energy and water budgets when the horizontal resolution of atmospheric models is increased and to identify common factors of these changes among models. To do so, we analyse an ensemble of twelve atmosphere-only and six coupled GCMs, with different model formulations and with resolutions spanning those of state-of-the-art coupled GCMs, i.e. from resolutions coarser than 100 km to resolutions finer than 25 km. The main changes in the global energy budget with resolution are a systematic increase in outgoing longwave radiation and decrease in outgoing shortwave radiation due to changes in cloud properties, and a systematic increase in surface latent heat flux; when resolution is increased from 100 to 25 km, the magnitude of the change of those fluxes can be as large as 5 W m−2. Moreover, all but one atmosphere-only model simulate a decrease of the poleward energy transport at higher resolution, mainly explained by a reduction of the equator-to-pole tropospheric temperature gradient. Regarding hydrological processes, our results are the following: (1) there is an increase of global precipitation with increasing resolution in all models (up to 40 × 103 km3 year−1) but the partitioning between land and ocean varies among models; (2) the fraction of total precipitation that falls on land is on average 10% larger at higher resolution in grid point models, but it is smaller at higher resolution in spectral models; (3) grid points models simulate an increase of the fraction of land precipitation due to moisture convergence twice as large as in spectral models; (4) grid point models, which have a better resolved orography, show an increase of orographic precipitation of up to 13 × 103 km3 year−1 which explains most of the change in land precipitation; (5) at the regional scale, precipitation pattern and amplitude are improved with increased resolution due to a better simulated seasonal mean circulation. We discuss our results against several observational estimates of the Earth's energy budget and hydrological cycle and show that they support recent high estimates of global precipitation