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

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

Contrôle des pesticides organochlorés dans le lait et produits laitiers : Bioaccumulation et risques d’exposition

La présente étude vise à déterminer les teneurs des pesticides organochlorés (POC) dans le lait de vache et du beurre élaboré traditionnellement. Ainsi, 90 échantillons de lait et 45 échantillons de beurre ont été collectés auprès des éleveurs installés dans les régionsde Buyo, Grand-lahou et Yamoussoukro. Ces échantillons ont été traités en vue de déterminer les résidus de 14 POC. Les analyses ont été menées par chromatographie en phase gazeuse sur colonne capillaire avec un détecteur à capture d'électrons (ECD). Les résultats observés révèlent une contamination générale du lait et du beurre par les POC.Ainsi, des charges moyennes en hexachlorocyclohexane (HCH) de 42,75 mg/kg et 165,94 mg/kg), en endosulfane de 31,58 et 436,80 mg/kg, en heptachlore 8,70 et 59,91 mg/kg et en Dichlorodiphenyltrichloroethane (DDT) 36,20 et 227,82 mg/kg, ont été respectivement déterminées dans le lait et dans le beurre. La teneur résiduelle moyenne des isomères HCH et des cyclodiènes (dieldrine, endosulfane et heptachlore) constitue respectivement 36,9 % et 13,2 % de la moyenne du total des POC mesurés dans le lait et respectivement 40,7 % et 28,2 % de celle mesurée dans le beurre. Le DDT et ses métabolites mesurés dans nos échantillons représentent 49,9 % du total des POC du lait et 31 % pour le beurre.Mots-clés : Pesticides organochlorés, lait de vache, bioaccumulation, écotoxicologie, lacs, Côte d’Ivoir

Etude cinétique de la dégradation de l’Endosufane en solution

Les pesticides sont fréquemment utilisés en Côte d’Ivoire. Leur détection dans les eaux de forage témoigne de leur mauvais usage et d’un grave problème agroenvironnemental. La photolyse directe ou la photocatalyse sont de nouvelles techniques d’oxydation, envisageables pour résoudre ce problème, avec l’avantage d’utiliser à terme les UV-A solaires. L’ a-endosulfane et le b-endosulfane ont été sélectionnés pour cette étude. Leurs dégradations dans l’eau de forage et dans l’eau déionisée ont été respectivement effectuées dans un réacteur muni d’une lampe basse pression de 6 watts ou par exposition à la lumière solaire. La photodégradation dans l’eau de forage est plus rapide que celle observée dans l’eau déionisée. On observe cependant une stabilité relative des isomères d’endosulfane sous irradiation solaire avec des temps de demi-vie de 770 h pour a endosulfane et 407 h pour b endosulfane. L’utilisation du photocatalyseur (Fe3+/H2O2) a accéléré la dégradation de l’endosulfane quelque soit la source d’irradiation. Sous irradiation solaire, les temps de demi-vie passent à 56,34 minutes et à 41,74 minutes respectivement pour l’a et le b endosulfane

Adaptation Strategies to Climate Change among Cereal Crop Farmers in Kita, Kayes Region of Mali

This study examined adaptation strategies to climate change among crop farmers in Kita, Kayes region of Mali. A multistage sampling procedure was used to select 109 respondents for this study. Structured interview schedule was used to elicit responses from respondents. Data were analysed using descriptive statistics - mean and percentages and inferential statistics - Pearson Product Moment Correlation (PPMC). Respondents were mostly male (58.7%), married (93.6%) and had no formal education (87.2%). Average age, household size, farming experience and output were 45.28±14.78 years, 16.70±10.65 persons. 29.70±13.75 years and 2,335.77±2,139.41kg, respectively. Respondents primarily engage in crop farming (100.0%) with majority producing at the subsistence level (99.1%) using sole cropping pattern (94.5%). Information sources on climate change effects were NGOs (90.8%) and friends/relatives (39.4%). Knowledge of climate change effects was high (76.4%) and prominent adaptation strategies used were timely planting (  =1.93) and planting of short cycled seed (  =1.12). Establishing cereal banks (98.4%), building and maintenance of small dams (95.9%), diversifying agricultural production (72.4%) and strengthening early warning systems (70.7%) were never used by most respondents. None of the respondents ever employed the use of zaï, half-moon (demi-lune) and stone cord as an adaptation strategies owing to inadequate financial capability. Significant relationship existed between farm size (r=0.201, p<0.05), household size (r=0.310, p<0.05),  sources of information (r=0.447, p<0.05), knowledge (r=0.326, p<0.05) and adaptation strategies. The study recommends that efforts be made by government and NGOs to disseminate and monitor farmers’ use of sustainable adaptation strategies so that substantial increase in production can be attained. Keywords: Adaptation strategies, Climate change, Cereal farmers, Mal

Adaptation Strategies to Climate Change among Cereal Crop Farmers in Kita, Kayes Region of Mali

This study examined adaptation strategies to climate change among crop farmers in Kita, Kayes region of Mali. A multistage sampling procedure was used to select 109 respondents for this study. Structured interview schedule was used to elicit responses from respondents. Data were analysed using descriptive statistics - mean and percentages and inferential statistics - Pearson Product Moment Correlation (PPMC). Respondents were mostly male (58.7%), married (93.6%) and had no formal education (87.2%). Average age, household size, farming experience and output were 45.28±14.78 years, 16.70±10.65 persons. 29.70±13.75 years and 2,335.77±2,139.41kg, respectively. Respondents primarily engage in crop farming (100.0%) with majority producing at the subsistence level (99.1%) using sole cropping pattern (94.5%). Information sources on climate change effects were NGOs (90.8%) and friends/relatives (39.4%). Knowledge of climate change effects was high (76.4%) and prominent adaptation strategies used were timely planting (  =1.93) and planting of short cycled seed (  =1.12). Establishing cereal banks (98.4%), building and maintenance of small dams (95.9%), diversifying agricultural production (72.4%) and strengthening early warning systems (70.7%) were never used by most respondents. None of the respondents ever employed the use of zaï, half-moon (demi-lune) and stone cord as an adaptation strategies owing to inadequate financial capability. Significant relationship existed between farm size (r=0.201, p<0.05), household size (r=0.310, p<0.05),  sources of information (r=0.447, p<0.05), knowledge (r=0.326, p<0.05) and adaptation strategies. The study recommends that efforts be made by government and NGOs to disseminate and monitor farmers’ use of sustainable adaptation strategies so that substantial increase in production can be attained. Keywords: Adaptation strategies, Climate change, Cereal farmers, Mal

Enhancement of magnetocaloric effect in the Gd2Al phase by Co alloying

To understand the effect of Co doping on the magnetic entropy changes in Gd2 Al phase, a series of Gd2AlCox alloys with 0 ≤ x ≤ 0.6 were synthesized by arc-melting and the crystal structure was analyzed by XRD. The magnetic properties were investigated, and the entropychanges were calculated for a magnetic field change of 50 kOe. All the as-cast alloys dopedwith Co exhibited greater magnetic entropy changes than the original binary Gd2 Al phase. The main reasons attributed to this are the increase of ferromagnetic interaction indicated by the disappearance of cusp and sharp drop in magnetization and the reduction of the critical field required to trigger the field-induced transition below 50 K in Gd2 Al phase after Co alloying

Dynamics of antigenemia and transmission intensity of Wuchereria bancrofti following cessation of mass drug administration in a formerly highly endemic region of Mali

Background After seven annual rounds of mass drug administration (MDA) in six Malian villages highly endemic for Wuchereria bancrofti (overall prevalence rate of 42.7%), treatment was discontinued in 2008. Surveillance was performed over the ensuing 5 years to detect recrudescence. Methods Circulating filarial antigen (CFA) was measured using immunochromatographic card tests (ICT) and Og4C3 ELISA in 6–7 year-olds. Antibody to the W. bancrofti infective larval stage (L3) antigen, Wb123, was tested in the same population in 2012. Microfilaraemia was assessed in ICT-positive subjects. Anopheles gambiae complex specimens were collected monthly using human landing catch (HLC) and pyrethrum spray catch (PSC). Anopheles gambiae complex infection with W. bancrofti was determined by dissection and reverse transcriptase polymerase chain reaction (RT-PCR) of mosquito pools. Results Annual CFA prevalence rates using ICT in children increased over time from 0% (0/289) in 2009 to 2.7% (8/301) in 2011, 3.9% (11/285) in 2012 and 4.5% (14/309) in 2013 (trend χ 2  = 11.85, df =3, P = 0.0006). Wb123 antibody positivity rates in 2013 were similar to the CFA prevalence by ELISA (5/285). Although two W. bancrofti-infected Anopheles were observed by dissection among 12,951 mosquitoes collected by HLC, none had L3 larvae when tested by L3-specific RT-PCR. No positive pools were detected among the mosquitoes collected by pyrethrum spray catch. Whereas ICT in 6–7 year-olds was the major surveillance tool, ICT positivity was also assessed in older children and adults (8–65 years old). CFA prevalence decreased in this group from 4.9% (39/800) to 3.5% (28/795) and 2.8% (50/1,812) in 2009, 2011 and 2012, respectively (trend χ 2  = 7.361, df =2, P = 0.0067). Some ICT-positive individuals were microfilaraemic in 2009 [2.6% (1/39)] and 2011 [8.3% (3/36)], but none were positive in 2012 or 2013. Conclusion Although ICT rates in children increased over the 5-year surveillance period, the decrease in ICT prevalence in the older group suggests a reduction in transmission intensity. This was consistent with the failure to detect infective mosquitoes or microfilaraemia. The threshold of ICT positivity in children may need to be re-assessed and other adjunct surveillance tools considered

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

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

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

Systematic gene function prediction from gene expression data by using a fuzzy nearest-cluster method

BACKGROUND: Quantitative simultaneous monitoring of the expression levels of thousands of genes under various experimental conditions is now possible using microarray experiments. However, there are still gaps toward whole-genome functional annotation of genes using the gene expression data. RESULTS: In this paper, we propose a novel technique called Fuzzy Nearest Clusters for genome-wide functional annotation of unclassified genes. The technique consists of two steps: an initial hierarchical clustering step to detect homogeneous co-expressed gene subgroups or clusters in each possibly heterogeneous functional class; followed by a classification step to predict the functional roles of the unclassified genes based on their corresponding similarities to the detected functional clusters. CONCLUSION: Our experimental results with yeast gene expression data showed that the proposed method can accurately predict the genes' functions, even those with multiple functional roles, and the prediction performance is most independent of the underlying heterogeneity of the complex functional classes, as compared to the other conventional gene function prediction approaches