Analyse comparative entre la distribution des fréquences de conductivité électrique et les faciès géochimiques des eaux des aquifères de socle (Côte d’Ivoire)

La conductivité électrique est un indicateur de la minéralisation totale des eaux et son étude permet de faire un suivi hydrochimique des systèmes hydrologiques. L'objectif de ce travail est d’analyser l’apport de l’étude de la distribution des fréquences de conductivité électrique à la caractérisation géochimique des eaux des aquifères fissurés de socle cristallin et cristallophyllien. Les zones tests utilisées dans le cadre de ce travail appartiennent au socle ivoirien. La méthodologie adoptée est basée d’une part sur l’étude des courbes de fréquence de conductivité électrique. D’autre part, les faciès chimiques des eaux souterraines ont été déterminés à partir du diagramme de Piper. L’analyse de la distribution des fréquences de conductivité électrique a fait ressortir diverses familles d’eau. La projection des échantillons d’eau sur le diagramme de Piper a permis de mettre en évidence plusieurs faciès des eaux souterraines. La comparaison des différents résultats met en évidence une concordance au niveau de quatre échantillons (Bondoukou, Tiassalé, ex-N’zi- Comoé et Tiébissou-Didievi) et une non concordance au niveau de deux échantillons (Guiglo-Duekoué et Agboville). On peut conclure que l’analyse des fréquences de conductivité électrique permet en général de confirmer les différents faciès hydrogéochimiques.© 2016 International Formulae Group. All rights reserved.Mots clés: Hydrogéochimie, conductivité électrique, diagramme de Piper, socle cristallin et cristallophyllien, Côte d’IvoireEnglish Title: Comparative analysis of electrical conductivity frequencies distribution and geochemical facies of hard rock aquifers waters (Ivory Coast)English AbstractElectrical conductivity is a measure of the total mineralization of the water and its study allows for a hydrochemical monitoring of water systems. The objective of this work was to analyze the contribution of the  study of electrical conductivity frequencies distribution to the geochemical characterization of the hard rock aquifers waters. The test zones used in the context of this work belong to the Ivorian hard rock aquifers. The methodology is based firstly on the study of the frequency curves of the electrical conductivity. On the other hand, chemical facies of groundwater have been determined from the Piper diagram. The analysis of the distribution of the electrical conductivity of frequencies has highlighted various water families. The projection of water samples on the Piper diagram helped highlight several facies of groundwater. Comparing the results of different methodological approaches reveals a match in four samples (Bondoukou, Tiassalé, N'zi-Comoé and Tiébissou-Didievi) and a mismatch in two samples (Guiglo-Duékoué and Agboville). Given concordances results in most cases, we can say that the analysis of the electrical conductivity of frequencies generally allows confirming the different hydrogeochemical facies in the hard rock aquifers.© 2016 International Formulae Group. All rights reserved.Keywords: Hydrogeochemistry, electrical conductivity, Piper diagram, hard rock aquifers, Ivory Coas

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

Caractérisation intra-annuelle de la variabilité climatique en Côte d’Ivoire

The objective of this work to analyze the impacts of climate change on seasonal weather patterns in Ivory Coast. The study was based on a monthly rainfall and thermometric database recorded at nine synoptic stations representing the main climatic regimes of the Ivory Coast. These data cover the period 1941-2016. The methodology adopted is based on the use of climatic indices (Angot index, Péguy index, Moral index, UNEP index) for the study of climate dynamics on an intra-annual scale. The results of the study showed that the seasonal and intra-annual climate in Ivory Coast underwent changes from the period before 1970 to the period after 1970. Indeed, the character "the cold semester is more watered that the hot semester” is more pronounced in the period before 1970 than in the period after 1970 with a tendency for the hottest semesters to be relatively more watered after 1970 in some localities. The period before 1970 records the three consecutive rainiest months with a change in the wettest quarter, that is observed over the period after 1970 in certain stations studied. Across the Ivorian territory, certain climatic zones experienced a change in the rainy season after 1970 in terms of the start, end and duration months. However, the upheaval observed did not affect the type of climate in Ivory Coast. It remained subhumid and humid, despite the decrease in wetness after 1970

Influence of hydrothermal treatment on physicochemical characteristics of white beans seeds (Phaseolus vulgaris) produced in Côte d’Ivoire

Objective: Beans are eaten after cooking and the cooking methods significantly affect their biochemical composition. In this study, the effect of traditional cooking methods such as boiling and steaming on the nutritional composition and anti-nutritional factors in white beans (Phaseolus vulgaris) was investigated.Methodology and Results: In both cooked and uncooked white beans, proximate composition and antinutritional components were determined according to standard methods. The results showed that cooking treatments decreased the nutritional and anti-nutritional composition in white beans. Boiling decreased the dry matter, ash, lipid, total carbohydrate and protein, with an average loss of 65.98 %; 31.18 %, 39.37 %; 83.42 % and 37.50 % respectively. The losses due to steaming were smaller than boiling with the values of 39.20 %, 13.06 %, 10.31 %, 54.94 % and 13.17 % respectively for the dry matter, ash, protein, lipid and reducing sugars. Excepted for phytates where losses due to steaming are slightly higher (6.38 %) compared to those of boiling (5.42 %), boiling induced higher losses on anti-nutritional composition such us total oxalates (62.88 %) and phenols (81.95 %) compared to steaming, which caused only of the less significant losses of 38.18 % and 73.42 % respectively.Conclusion and application of results. As shown in this study steaming and boiling cooking affect the composition of white bean. They induce a loss in nutritional compounds and anti-nutritional factors in the bean. However, steaming of white bean caused slight losses in nutritional composition and antinutritional factors than boiling. Steaming could be recommended in infant feeding because it preserves nutrients necessary for their developmentKeywords: hydrothermal, steaming, boiling, white bean seed, losses, Côte d’Ivoir

Analyse des impacts des changements climatiques sur les normes hydrologiques en Afrique de l’Ouest : cas du district d’Abidjan (sud de la Côte d’Ivoire)

La connaissance des quantiles de précipitations extrêmes comme normes hydrologiques est nécessaire dans le cadre de projets d’aménagement pour la conception d’ouvrages hydrauliques et dans de nombreuses applications d’ingénierie. Dans un contexte de changements climatiques constatés en Afrique de l’Ouest, l’estimation des précipitations associées aux événements extrêmes est un sujet qui suscite des réflexions. Cette problématique soulève la question principale suivante : « Sur quelle base pourrait-on/devrait-on élaborer de nouveaux quantiles pour la gestion de projets de construction d’ouvrages hydrauliques? » Ainsi, l’objectif de cette étude est l’analyse des impacts des changements climatiques sur les normes hydrologiques relatives aux quantiles des pluies journalières maximales annuelles dans le district d’Abidjan (sud de la Côte d’Ivoire). L’approche méthodologique utilisée a consisté à la collecte de données de pluviométrie journalière pour la période 1961-2014. Les tests statistiques de base ont été effectués. Le choix du modèle statistique s’est porté sur la loi de Gumbel. Les paramètres du modèle ont été estimés et ont permis de calculer les quantiles sur plusieurs périodes de référence (1961-1990, 1971-2000, 1981-2010, 1961-2014) et plusieurs durées de retour (2, 5, 10, 20, 50 et 100 ans). Une comparaison des quantiles déterminés a été réalisée à partir des matrices d’écarts relatifs absolus. Les principaux résultats ont montré que les différentes séries définies sont constituées de valeurs indépendantes, stationnaires et homogènes. Les quantiles calculés varient pour une durée de retour donnée en fonction des périodes de référence choisies pour leur détermination. Cela traduit une non-stationnarité des quantiles due à l’instabilité du climat. Pour une meilleure sécurité des ouvrages hydrauliques, les recommandations de ce travail proposent d’utiliser les quantiles de la période historique (1961-1990) pour les périodes de retour inférieures à 50 ans. En ce qui concerne les durées de retour supérieures à 50 ans, il est possible d’utiliser les quantiles de deux périodes de référence (1961-1990, 1981-2010). Pour la valeur du gradex des méthodes empiriques de l’Office de la recherche scientifique et technique outre-mer (ORSTOM) et du Comité interafricain d’études hydrauliques (CIEH), il est recommandé de considérer 0,44 comme valeur pour le dimensionnement des ouvrages hydrauliques dans le district d’Abidjan.Knowledge of quantiles of extreme precipitation as hydrological standards is required for the design of hydraulic projects and many other engineering applications. In the context of climate change in West Africa, the estimation of precipitation associated with extreme events is an issue to be adressed. This raises one main question: "On what basis can new quantiles be developed for the management of hydraulic work construction projects?" The objective of this study is the analysis of the impacts of climate change on the hydrological standards relating to the quantiles of maximum daily rainfall in the Abidjan District (southern Ivory Coast). The methodological approach used was to collect daily precipitation data covering the period 1961-2014. Basic statistical tests were performed. The choice of the statistical model was based on Gumbel's law. The parameters of the model were estimated and the quantiles calculated for several reference periods (1961-1990, 1971-2000, 1981-2010, 1961-2014) and return periods (2, 5, 10, 20, 50 and 100 years). A comparison of the quantiles determined was performed from the absolute relative deviation matrices. The main results showed that the different series defined are made up of independent, stationary, and homogeneous values. The quantiles calculated vary for a given return period as a function of the reference periods chosen for their determination. This reflects a non-stationarity of the quantiles due to climate instability. For improved safety of hydraulic works, the recommendation of this work is to use quantiles of the historical period (1961-1990) for return periods of less than 50 years. For return periods over 50 years, it is possible to use quantiles of two reference periods (1961-1990, 1981-2010). For the gradex value of the empirical methods of ORSTOM (Office de la recherche scientifique et technique outre-mer) and Inter-African Committee for Hydraulic Studies (CIEH), it is recommended to consider 0.44 for sizing hydraulic works in the Abidjan District