216 research outputs found

    Hydro-political assessment of water governance from the top-down and review of literature on local level institutions and practices in the Volta Basin

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    Water resource management / Governance / River basin development / Water law / Colonialism / Institutions / Social participation / Women / Water use

    Systùmes de production et pratiques à risque en agriculture urbaine: Cas du maraüchage dans la ville de Yamoussoukro en Cîte d’Ivoire

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    La question de l’impact de l’agriculture urbaine sur l’environnement revient, fréquemment, au coeur des débats dans la gestion des villes africaines, comme Yamoussoukro. Les inquiétudes liées à la préservation de l’environnement urbain, eu égard à l’usage de pesticides et à la qualité des eaux utilisées, constituent une préoccupation prise en compte dans le cadre de cette étude. Celle-ci porte, aussi bien sur l’évaluation du risque sur l’environnement consécutif à de mauvaises pratiques agricoles que sur l’évaluation du risque sanitaire consécutif à l’usage des eaux usées. Pour atteindre cet objectif, la méthodologie utilisée a été d’une part, la collecte de données, à travers une enquête et d’autre part, des analyses au laboratoire. Il ressort que le maraîchage urbain à Yamoussoukro est une activité informelle. Les cultures pratiquées sont dominées par la laitue, l’oignon vert et la carotte. Le recours aux intrants, notamment les pesticides, est très répandu. Les dispositifs règlementaires sur la distribution des produits agrochimiques ne sont pas appliqués. Ainsi, 74% des pesticides recensés ne sont pas homologués pour les cultures maraîchères, 12% sont très toxiques (classe Ib) et 57% nocifs (classe II). Les risques encourus sont accentués par un traitement chimique qui n’est pas suffisamment maîtrisé. Les analyses physico-chimiques et microbiologiques ont mis en évidence, d’une part, des eaux d’irrigation aux caractéristiques très hétérogènes et d’autre part, une grande diversité microbienne et une contamination de ces eaux, suggérant des risques sanitaires avérés.Mots clés: cultures maraîchères, environnement, risque sanitaire, pesticides, eau

    Contamination du lait caillĂ© et de l’oeuf consommĂ© en CĂŽte d’Ivoire par des pesticides organochlorĂ©s

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    La prĂ©sente Ă©tude vise Ă  Ă©valuer l’aspect sanitaire de l’alimentation humaine Ă  travers deux produits Ă  forte consommation en CĂŽte d’Ivoire : le lait caillĂ© et l’oeuf. Ainsi, 30 Ă©chantillons de lait caillĂ© ont Ă©tĂ© achetĂ©s et 30 Ă©chantillons d’oeufs de poulet ont Ă©tĂ© collectĂ©s dans trois fermes dans la ville d’Abidjan. Ces Ă©chantillons ont Ă©tĂ© traitĂ©s dans le but de dĂ©terminer les rĂ©sidus de 12 POC (Pesticides OrganoChlorĂ©s). Les analyses ont Ă©tĂ© rĂ©alisĂ©es au CG sur colonne capillaire avec un dĂ©tecteur Ă  capture d'Ă©lectrons. Les rĂ©sultats observĂ©s rĂ©vĂšlent une contamination du lait caillĂ© et de l’oeuf par 5 POC. Ainsi, des charges moyennes en ÎŒg/kg des isomĂšres hexachlorocyclohexane (HCH) allant de 0,125 Ă  0,997 et de 1,870 Ă  35,907, de l’endosulfan allant de 0,045 Ă  0,563 et non dĂ©tectĂ©, de la dieldrine allant de 0,025 Ă  0,263 et de 5,727 Ă  69,710 et du Dichlorodiphenyltrichloroethane (DDT) et mĂ©tabolites allant de 0,133 Ă  0,813 et de 21,105 Ă  75,22, ont Ă©tĂ© respectivement dĂ©terminĂ©es dans le lait caillĂ© et dans l’oeuf. La teneur rĂ©siduelle moyenne des isomĂšres HCH, des cyclodiĂšnes (dieldrine, et endosulfane) et du DDT et ses mĂ©tabolites constituent respectivement 40%, 40% et 20% de la moyenne du total des POC mesurĂ©s dans le lait caillĂ© et respectivement 20%, 20% et 60% de celle mesurĂ©e dans l’oeuf.Mots-clĂ©s: pesticides organochlorĂ©s, lait caillĂ©, oeuf, CĂŽte d’Ivoire. Contamination of the curdled milk and the egg consumed in Ivory Coast by organochlorinated pesticides This study aims to determine the levels of organochlorinated pesticides (OCPs) in the curdled milk and egg. Thus, 30 samples of curdled milk were purchased and 30 egg samples were collected from three farms in the area of the lagoons. These samples were processed in order to determine the residues 12 OCPs. Analyses were performed by GC capillary column with electron capture detector. The observed results indicate contamination of curdled milk and egg by 5 OCPs. Thus, average loads in ÎŒg/kg of hexachlorocyclohexane (HCH) isomers ranging from 0.125 to 0.997 and 1.870 to 35.907, endosulfan ranging from 0.045 to 0.563 and undetected, dieldrin ranging from 0.025 to 0.263 and 5.727 to 69.710 and dichlorodiphenyltrichloroethane (DDT) and metabolites ranging from 0.133 to 0.813 and 21, 105 to 75.22, respectively, were determined in the curdled milk and egg. The average residual HCH isomers, cyclodiene (dieldrin and endosulfan) and DDT and its metabolites is respectively 40%, 40% and 20% of the average total OCPs measured in curdled milk and respectively 20%, 20 % and 60% of that measured in the bud.Keywords: organochlorinated pesticides, curdled milk, egg, Ivory Coast

    SMART: Unique splitting-while-merging framework for gene clustering

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    Copyright @ 2014 Fa et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Successful clustering algorithms are highly dependent on parameter settings. The clustering performance degrades significantly unless parameters are properly set, and yet, it is difficult to set these parameters a priori. To address this issue, in this paper, we propose a unique splitting-while-merging clustering framework, named “splitting merging awareness tactics” (SMART), which does not require any a priori knowledge of either the number of clusters or even the possible range of this number. Unlike existing self-splitting algorithms, which over-cluster the dataset to a large number of clusters and then merge some similar clusters, our framework has the ability to split and merge clusters automatically during the process and produces the the most reliable clustering results, by intrinsically integrating many clustering techniques and tasks. The SMART framework is implemented with two distinct clustering paradigms in two algorithms: competitive learning and finite mixture model. Nevertheless, within the proposed SMART framework, many other algorithms can be derived for different clustering paradigms. The minimum message length algorithm is integrated into the framework as the clustering selection criterion. The usefulness of the SMART framework and its algorithms is tested in demonstration datasets and simulated gene expression datasets. Moreover, two real microarray gene expression datasets are studied using this approach. Based on the performance of many metrics, all numerical results show that SMART is superior to compared existing self-splitting algorithms and traditional algorithms. Three main properties of the proposed SMART framework are summarized as: (1) needing no parameters dependent on the respective dataset or a priori knowledge about the datasets, (2) extendible to many different applications, (3) offering superior performance compared with counterpart algorithms.National Institute for Health Researc

    Seasonality and shift in age-specific malaria prevalence and incidence in Binko and CarriÚre villages close to the lake in Selingué, Mali

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    BACKGROUND: Malaria transmission in Mali is seasonal and peaks at the end of the rainy season in October. This study assessed the seasonal variations in the epidemiology of malaria among children under 10 years of age living in two villages in SelinguĂ©: CarriĂšre, located along the Sankarani River but distant from the hydroelectric dam, and Binko, near irrigated rice fields, close to the dam. The aim of this study was to provide baseline data, seasonal pattern and age distribution of malaria incidence in two sites situated close to a lake in SelinguĂ©. METHODS: Geographically, SelinguĂ© area is located in the basin of Sakanrani and belongs to the district of Yanfolila in the third administrative region of Mali, Sikasso. Two cross-sectional surveys were conducted in October 2010 (end of transmission season) and in July 2011 (beginning of transmission season) to determine the point prevalence of asymptomatic parasitaemia, and anaemia among the children. Cumulative incidence of malaria per month was determined in a cohort of 549 children through active and passive case detection from November 2010 through October 2011. The number of clinical episodes per year was determined among the children in the cohort. Logistic regression was used to determine risk factors for malaria. RESULTS: The prevalence of malaria parasitaemia varied significantly between villages with a strong seasonality in CarriĂšre (52.0–18.9 % in October 2010 and July 2011, respectively) compared with Binko (29.8–23.8 % in October 2010 and July 2011, respectively). Children 6–9 years old were at least twice more likely to carry parasites than children up to 5 years old. For malaria incidence, 64.8–71.9 % of all children experienced at least one episode of clinical malaria in Binko and CarriĂšre, respectively. The peak incidence was observed between August and October (end of the rainy season), but the incidence remained high until December. Surprisingly, the risk of clinical malaria was two- to nine-fold higher among children 5–9 years old compared to younger children. CONCLUSIONS: A shift in the peak of clinical episodes from children under 5–9 years of age calls for expanding control interventions, such as seasonal malaria chemoprophylaxis targeting the peak transmission months

    Utilisation des facteurs climatiques pour la surveillance de la fréquence des occurrences de méningite/ paludisme à Bamako

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    Objectif : Notre travail consiste Ă  : DĂ©terminer les pĂ©riodes de risque pour la mĂ©ningite et le paludisme Ă  Bamako; Etablir une corrĂ©lation entre : - d’une part les paramĂštres mĂ©tĂ©orologiques (tempĂ©rature de l’air, humiditĂ© relative de l’air, pluviomĂ©trie, insolation et vitesse du vent) et la frĂ©quence des occurrences de paludisme ; - d’autre part les mĂȘmes paramĂštres pour la mĂ©ningite. MĂ©thode : Nous avons fait une Ă©tude rĂ©trospective de l’évolution du paludisme et de la mĂ©ningite en fonction de la variation des paramĂštres mĂ©tĂ©orologiques (tempĂ©rature de l’air, humiditĂ© relative de l’air, pluviomĂ©trie, insolation et vitesse du vent) Ă  Bamako. RĂ©sultats : Le paludisme, rare au 1er et 2Ăšm trimestres, est trĂšs frĂ©quent au 3Ăš trimestre et au 4Ăš trimestre. Quant Ă  la mĂ©ningite elle est frĂ©quente au premier semestre et rare pendant le reste de l’annĂ©e. La frĂ©quence du paludisme est liĂ©e Ă  la tempĂ©rature moyenne de l’air, Ă  la grande humiditĂ© de l’air, Ă  la pluviomĂ©trie abondante, Ă  la faible insolation et Ă  la faible vitesse du vent. La frĂ©quente de la mĂ©ningite est liĂ©e Ă  la haute tempĂ©rature de l’air, Ă  la faible humiditĂ© de l’air, Ă  la faible pluviomĂ©trie, Ă  la forte insolation et Ă  la grande vitesse du vent. Conclusion : La frĂ©quence du paludisme est liĂ©e Ă  la grande humiditĂ©, et Ă  la faible insolation. Quant Ă  la mĂ©ningite, sa frĂ©quence est liĂ©e Ă  la haute tempĂ©rature, Ă  la grande vitesse du vent et Ă  la forte insolation

    A repurposing strategy for Hsp90 inhibitors demonstrates their potency against filarial nematodes

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    Novel drugs are required for the elimination of infections caused by filarial worms, as most commonly used drugs largely target the microfilariae or first stage larvae of these infections. Previous studies, conducted in vitro, have shown that inhibition of Hsp90 kills adult Brugia pahangi. As numerous small molecule inhibitors of Hsp90 have been developed for use in cancer chemotherapy, we tested the activity of several novel Hsp90 inhibitors in a fluorescence polarization assay and against microfilariae and adult worms of Brugia in vitro. The results from all three assays correlated reasonably well and one particular compound, NVP-AUY922, was shown to be particularly active, inhibiting Mf output from female worms at concentrations as low as 5.0 nanomolar after 6 days exposure to drug. NVP-AUY922 was also active on adult worms after a short 24 h exposure to drug. Based on these in vitro data, NVP-AUY922 was tested in vivo in a mouse model and was shown to significantly reduce the recovery of both adult worms and microfilariae. These studies provide proof of principle that the repurposing of currently available Hsp90 inhibitors may have potential for the development of novel agents with macrofilaricidal properties

    The Schistosomiasis Control Initiative (SCI): rationale, development and implementation from 2002-2008

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    Schistosomiasis remains one of the most prevalent parasitic diseases in developing countries. After malaria, schistosomiasis is the most important tropical disease in terms of human morbidity with significant economic and public health consequences. Although schistosomiasis has recently attracted increased focus and funding for control, it has been estimated that less than 20% of the funding needed to control the disease in Africa is currently available. In this article the following issues are discussed: the rationale, development and objectives of the Schistosomiasis Control Initiative (SCI)-supported programmes; the management approaches followed to achieve implementation by each country; mapping, monitoring and evaluation activities with quantifiable impact of control programmes; monitoring for any potential drug resistance; and finally exit strategies within each country. The results have demonstrated that morbidity due to schistosomiasis has been reduced by the control programmes. While challenges remain, the case for the control of schistosomiasis has been strengthened by research by SCI teams and the principle that a national programme using ‘preventive chemotherapy' can be successfully implemented in sub-Saharan Africa, whenever the resources are available. SCI and partners are now actively striving to raise further funds to expand the coverage of integrated control of neglected tropical diseases (NTDs) in sub-Saharan Afric

    Mof-associated complexes have overlapping and unique roles in regulating pluripotency in embryonic stem cells and during differentiation

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    The histone acetyltransferase (HAT) Mof is essential for mouse embryonic stem cell (mESC) pluripotency and early development. Mof is the enzymatic subunit of two different HAT complexes, MSL and NSL. The individual contribution of MSL and NSL to transcription regulation in mESCs is not well understood. Our genome-wide analysis show that i) MSL and NSL bind to specific and common sets of expressed genes, ii) NSL binds exclusively at promoters, iii) while MSL binds in gene bodies. Nsl1 regulates proliferation and cellular homeostasis of mESCs. MSL is the main HAT acetylating H4K16 in mESCs, is enriched at many mESC-specific and bivalent genes. MSL is important to keep a subset of bivalent genes silent in mESCs, while developmental genes require MSL for expression during differentiation. Thus, NSL and MSL HAT complexes differentially regulate specific sets of expressed genes in mESCs and during differentiation
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