Pauvreté et accès à l'eau dans la vallée du Sénégal

Water poverty in the Senegal Valley Considering the flood-recession agriculture, the hydraulic history of the valley of the Senegal River is ancient, but knows a deep mutation since the introduction of the irrigation. Can one speak of water poverty, whereas two dams now control the water flow of the Senegal River and ensure a permanent abundance in water ? The answer to this questioning is proposed through the link between poverty, access to funding, access to land, and involvement in resource management.L'histoire hydraulique de la vallée du fleuve Sénégal est ancienne et remonte à la culture de décrue. Mais elle connaît une profonde mutation depuis l'introduction de l'irrigation. Peut-on parler de « pauvreté hydraulique », alors que deux barrages régulent à présent le régime du fleuve Sénégal et assurent une permanence de l'abondance en eau ? La réponse à cette question est proposée sous l'angle de l'articulation entre la pauvreté, l'accès au financement, l'accès au foncier, la participation à la gestion de la ressource

Approximation of conformal mappings using conformally equivalent triangular lattices

Consider discrete conformal maps defined on the basis of two conformally equivalent triangle meshes, that is edge lengths are related by scale factors associated to the vertices. Given a smooth conformal map $f$, we show that it can be approximated by such discrete conformal maps $f^\epsilon$. In particular, let $T$ be an infinite regular triangulation of the plane with congruent triangles and only acute angles (i.e.\ $<\pi/2$). We scale this tiling by $\epsilon>0$ and approximate a compact subset of the domain of $f$ with a portion of it. For $\epsilon$ small enough we prove that there exists a conformally equivalent triangle mesh whose scale factors are given by $\log|f'|$ on the boundary. Furthermore we show that the corresponding discrete conformal maps $f^\epsilon$ converge to $f$ uniformly in $C^1$ with error of order $\epsilon$.Comment: 14 pages, 3 figures; v2 typos corrected, revised introduction, some proofs extende

Caractérisation hydrochimique des aquifères fissurés de la région de San- Pedro (Sud-Ouest de la Côte d’Ivoire)

La r&eacute;gion de San-Pedro est situ&eacute;e dans le Sud-Ouest de la C&ocirc;te d&rsquo;Ivoire. Son substratum est constitu&eacute; de roches cristallines et m&eacute;tamorphiques fractur&eacute;es. L&rsquo;objectif de la pr&eacute;sente &eacute;tude est de mieux conna&icirc;tre lespropri&eacute;t&eacute;s hydrochimiques et les m&eacute;canismes d&rsquo;acquisition de la min&eacute;ralisation des eaux souterraines de la r&eacute;gion de San-Pedro. La base de donn&eacute;es comporte les donn&eacute;es des analyses physico-chimiques des eaux souterraines des aquif&egrave;res fissur&eacute;s et des fiches techniques des forages. L&rsquo;approche hydrochimique et l&rsquo;Analyse en Composantes Principales Norm&eacute;es ont &eacute;t&eacute; utilis&eacute;es pour le traitement de ces donn&eacute;es. Les r&eacute;sultats de cette &eacute;tude montrent que les eaux souterraines de San-Pedro sont caract&eacute;ris&eacute;es par une faible min&eacute;ralisation. Elles se subdivisent en deux principaux hydrofaci&egrave;s : les eaux bicarbonat&eacute;es et les eaux chlorur&eacute;es. D&rsquo;apr&egrave;s le syst&egrave;me calco-carbonique, on distingue trois familles d&rsquo;eau dans la zone d&rsquo;&eacute;tude en fonction des indices de saturation vis-&agrave;-vis des carbonates : les eaux &agrave; circulation tr&egrave;s lente, les eaux &agrave; circulation lente et les eaux &agrave; circulation rapide. L&rsquo;ACPN a permis de mettre en &eacute;vidence trois ph&eacute;nom&egrave;nes principaux gouvernant la min&eacute;ralisation des eaux souterraines : le temps de s&eacute;jour de l&rsquo;eau dans la roche aquif&egrave;re, les apports superficiels et l&rsquo;hydrolyse acide. Les eaux souterraines de la r&eacute;gion de San-Pedro sont potables pour la consommation des populations humaines d&rsquo;une mani&egrave;re g&eacute;n&eacute;rale. Ces r&eacute;sultats concourent &agrave; une meilleure connaissance des propri&eacute;t&eacute;s hydrochimiques des ressources en eaux souterraines du socle cristallin de C&ocirc;te d&rsquo;Ivoire

Pauvreté et accès à l'eau dans la vallée du Sénégal

L'histoire hydraulique de la vallée du fleuve Sénégal est ancienne et remonte à la culture de décrue. Mais elle connaît une profonde mutation depuis l'introduction de l'irrigation. Peut-on parler de « pauvreté hydraulique », alors que deux barrages régulent à présent le régime du fleuve Sénégal et assurent une permanence de l'abondance en eau ? La réponse à cette question est proposée sous l'angle de l'articulation entre la pauvreté, l'accès au financement, l'accès au foncier, la participation à la gestion de la ressource.HYDRAULIQUE ; HISTOIRE ; AMENAGEMENT HYDROAGRICOLE ; CULTURE DE DECRUE ; CULTURE IRRIGUEE ; SORGHO ; MIL ; RIZ IRRIGUE ; ACCES A LA TERRE ; RESSOURCES EN EAU ; GESTION DE L'ENVIRONNEMENT ; ACCES AU CREDIT ; TENURE FONCIERE ; ENDETTEMENT ; EXCLUSION SOCIALE ; PAUVRETE ; REVENUS AGRICOLES ; ORGANISATION PAYSANNE ; ACCES A L'EAU ; GESTION DE L'EAU ; SENEGAL ; FLEUVE SENEGAL VALLEE

A Schwarz lemma for K\"ahler affine metrics and the canonical potential of a proper convex cone

This is an account of some aspects of the geometry of K\"ahler affine metrics based on considering them as smooth metric measure spaces and applying the comparison geometry of Bakry-Emery Ricci tensors. Such techniques yield a version for K\"ahler affine metrics of Yau's Schwarz lemma for volume forms. By a theorem of Cheng and Yau there is a canonical K\"ahler affine Einstein metric on a proper convex domain, and the Schwarz lemma gives a direct proof of its uniqueness up to homothety. The potential for this metric is a function canonically associated to the cone, characterized by the property that its level sets are hyperbolic affine spheres foliating the cone. It is shown that for an $n$-dimensional cone a rescaling of the canonical potential is an $n$-normal barrier function in the sense of interior point methods for conic programming. It is explained also how to construct from the canonical potential Monge-Amp\`ere metrics of both Riemannian and Lorentzian signatures, and a mean curvature zero conical Lagrangian submanifold of the flat para-K\"ahler space.Comment: Minor corrections. References adde

Lack of correlation of stem cell markers in breast cancer stem cells

BACKGROUND: Various markers are used to identify the unique sub-population of breast cancer cells with stem cell properties. Whether these markers are expressed in all breast cancers, identify the same population of cells, or equate to therapeutic response is controversial. METHODS: We investigated the expression of multiple cancer stem cell markers in human breast cancer samples and cell lines in vitro and in vivo, comparing across and within samples and relating expression with growth and therapeutic response to doxorubicin, docetaxol and radiotherapy. RESULTS: CD24, CD44, ALDH and SOX2 expression, the ability to form mammospheres and side-population cells are variably present in human cancers and cell lines. Each marker identifies a unique rather than common population of cancer cells. In vivo, cells expressing these markers are not specifically localized to the presumptive stem cell niche at the tumour/stroma interface. Repeated therapy does not consistently enrich cells expressing these markers, although ER-negative cells accumulate. CONCLUSIONS: Commonly employed methods identify different cancer cell sub-populations with no consistent therapeutic implications, rather than a single population of cells. The relationships of breast cancer stem cells to clinical parameters will require identification of specific markers or panels for the individual cancer

Autopsy in adults with congenital heart disease (ACHD).

The adult congenital heart diseases (ACHD) population is exceeding the pediatric congenital heart diseases (CHD) population and is progressively expanding each year, representing more than 90% of patients with CHD. Of these, about 75% have undergone surgical and/or percutaneous intervention for palliation or correction. Autopsy can be a very challenging procedure in ACHD patients. The approach and protocol to be used may vary depending on whether the pathologists are facing native disease without surgical or percutaneous interventions, but with various degrees of cardiac remodeling, or previously palliated or corrected CHD. Moreover, interventions for the same condition have evolved over the last decades, as has perioperative myocardial preservations and postoperative care, with different long-term sequelae depending on the era in which patients were operated on. Careful clinicopathological correlation is, thus, required to assist the pathologist in performing the autopsy and reaching a diagnosis regarding the cause of death. Due to the heterogeneity of the structural abnormalities, and the wide variety of surgical and interventional procedures, there are no standard methods for dissecting the heart at autopsy. In this paper, we describe the most common types of CHDs that a pathologist could encounter at autopsy, including the various types of surgical and percutaneous procedures and major pathological manifestations. We also propose a practical systematic approach to the autopsy of ACHD patients

Nonperturbative aspects of ABJM theory

Using the matrix model which calculates the exact free energy of ABJM theory on S^3 we study non-perturbative effects in the large N expansion of this model, i.e., in the genus expansion of type IIA string theory on AdS4xCP^3. We propose a general prescription to extract spacetime instanton actions from general matrix models, in terms of period integrals of the spectral curve, and we use it to determine them explicitly in the ABJM matrix model, as exact functions of the 't Hooft coupling. We confirm numerically that these instantons control the asymptotic growth of the genus expansion. Furthermore, we find that the dominant instanton action at strong coupling determined in this way exactly matches the action of an Euclidean D2-brane instanton wrapping RP^3.Comment: 26 pages, 14 figures. v2: small corrections, final version published in JHE

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

La transmission du paludisme dans le delta du fleuve Sénégal a été étudiée dans trois villages, deux villages de riziculture irriguée dont un d'aménagement récent et un village de culture pluviale traditionnelle. La riziculture irriguée a entraîné une pullulation de moustiques et principalement d'#Anopheles pharoensis. La densité de ses populations est très importante et liée aux cycles des cultures dans la zone rizicole, son indice d'anthropophilie est élevé mais la longévité des femelles est très faible. #An. gambiae s.l. vecteur majeur du paludisme au Sénégal est, dans le delta, remplacé par #An. pharoensis$, vecteur secondaire dont l'aptitude à assurer une bonne transmission n'est pas prouvée. La riziculture irriguée n'a pas entraîné une augmentation de la transmission du paludisme. (Résumé d'auteur