Accès social à l'eau : étude de cas dans un village mossi du Yatenga

L’objectif de ce mémoire est d’examiner l’accès à l’eau d’un point de vue non pas technologique mais social. Toute société humaine a eu à régler la question de l’accès à l’eau. C’est particulièrement le cas des populations vivant sous un climat aride comme au Sahel, où cette ressource est rare. Le village d’étude est situé au nord du Burkina Faso, dans la région du Yatenga. J’examinerai d’abord la répartition temporelle et spatiale des groupes et des puits sur le territoire, puis la question de la régulation de l’accès à l’eau en tant qu’enjeu politique au sein des structures traditionnelles. Je montrerai qu’il permet tantôt de renforcer les hiérarchies sociales existantes, et tantôt de les dépasser. J’examinerai enfin l’accès à l’eau de différents groupes d’usagers : femmes, hommes, jeunes, vieux, agriculteurs, éleveurs. Je montrerai que leur condition d’accès est implicitement régulée, et limite les possibilités d’expansion économique de certains d’entre eux. Dans cette société en mutation, les usagers désavantagés peuvent développer des tactiques leur permettant de contourner ces contraintes. L’accès à l’eau est alors pris dans un jeu de stratégies antagonistes, celle de la reproduction sociale et celle du changement.The purpose of this report is to examine access to water, not from a technological but from a social point of view. Any human society has had to cope with the issue of access to water. This is especially true for the people living under arid climates such as in Sahel, where water is a limiting resource. The village under study is located in the Yatenga region, north of Burkina Faso. I will first examine the space and time distribution of wells and of human groups in this territory, then I will question the regulation of access to water as a political issue within traditional structures. I will show that it contributes to sometimes strengthen and sometimes circumvent patterns of social hierarchy. Then I will study access to water in different social groups: women, men, younger and older people, elders, farmers, herders. I will show that their access to water is implicitly checked, thus limiting opportunities of economical improvement for some of them. In this developing society, disadvantaged users may develop tactics to circumvent these constraints. Thus access to water is taken between conflicting strategies, pertaining to social reproduction as opposed to social change

Impact of Groundwater Flow on Permafrost Degradation and Transportation Infrastructure Stability

INE/AUTC 13.0

Histoire des sciences de la vie et de la terre

Claudine Cohen, maîtresse de conférencesMichel Veuille, directeur d’études à l’EPHE Évolution : épistémologie et histoire La « théorie de l’évolution » est à partir de 1859 une des grandes idées unificatrices en biologie, au même titre que la théorie cellulaire à partir du début du XIXe siècle, et que la biologie moléculaire depuis 1953. Dans les années 1940, avec ce qu’on a appelé la « synthèse évolutive », la biologie évolutive est devenue un champ de recherche organisant la convergence d’u..

Histoire des sciences de la vie et de la terre

Claudine Cohen, maître de conférencesMichel Veuille, directeur d’études à lΈΡΗΕ Évolution : épistémologie et histoire Ce séminaire intensif, issu de la collaboration d’une historienne des sciences et d’un biologiste généticien des populations, a exploré l’histoire du transformisme et de l’évolutionnisme, depuis le XVIIIe siècle jusqu’à nos jours, croisant l’approche historique et épistémologique des théories, des concepts et des problèmes et l’étude de leur inscription dans la science contemp..

DNA barcode analysis: a comparison of phylogenetic and statistical classification methods

<p>Abstract</p> <p>Background</p> <p>DNA barcoding aims to assign individuals to given species according to their sequence at a small locus, generally part of the CO1 mitochondrial gene. Amongst other issues, this raises the question of how to deal with within-species genetic variability and potential transpecific polymorphism. In this context, we examine several assignation methods belonging to two main categories: (i) phylogenetic methods (neighbour-joining and PhyML) that attempt to account for the genealogical framework of DNA evolution and (ii) supervised classification methods (k-nearest neighbour, CART, random forest and kernel methods). These methods range from basic to elaborate. We investigated the ability of each method to correctly classify query sequences drawn from samples of related species using both simulated and real data. Simulated data sets were generated using coalescent simulations in which we varied the genealogical history, mutation parameter, sample size and number of species.</p> <p>Results</p> <p>No method was found to be the best in all cases. The simplest method of all, "one nearest neighbour", was found to be the most reliable with respect to changes in the parameters of the data sets. The parameter most influencing the performance of the various methods was molecular diversity of the data. Addition of genetically independent loci - nuclear genes - improved the predictive performance of most methods.</p> <p>Conclusion</p> <p>The study implies that taxonomists can influence the quality of their analyses either by choosing a method best-adapted to the configuration of their sample, or, given a certain method, increasing the sample size or altering the amount of molecular diversity. This can be achieved either by sequencing more mtDNA or by sequencing additional nuclear genes. In the latter case, they may also have to modify their data analysis method.</p

Population genomics of sub-Saharan Drosophila melanogaster: African diversity and non-African admixture

(ABRIDGED) We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia), while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa FST were found to be enriched in genomic regions of locally elevated cosmopolitan admixture, possibly reflecting a role for some of these loci in driving the introgression of non-African alleles into African populations

L’évolution du genre Jaera Leach (Isopodes; Asellotes) et ses rapports avec l’histoire de la Méditerranée

The genus Jaera includes 19 species or subspecies, mostly endemic to Europe. The new forms J. nordmanni nordmanni, J. n. occidentalis, Jaera istri, and J. n. illyrica are described. The phylogeny of this group can be inferred. The cladogenetic events leading to its differentiation appear closely correlated to the origin of the Mediterranean basin and to the glacial periods

C. J. Lumsden & E. O. Wilson, Genes, Mind, and Culture. The Revolutionary Process

Veuille Michel. C. J. Lumsden & E. O. Wilson, Genes, Mind, and Culture. The Revolutionary Process. In: L'Homme, 1983, tome 23 n°1. pp. 151-153

Une théorie de l'inné qui n'est pas acquise

Veuille Michel. Une théorie de l'inné qui n'est pas acquise. In: Raison présente, n°57, 1er trimestre 1981. Le matin des biologistes ? pp. 67-89