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

FUNCTIONAL PROPERTIES OF FERMENTED AND UNFERMENTED COCOA PLACENTA POWDERS (THEOBROMA CACAO L.) FOR THE PRODUCTION OF BISCUITS

This study aims to examine the effects of fermentation on the functional properties of placenta powder for their use in the food industry. Cocoa placenta from freshly harvested pods was used for this study. A part was fermented, dried, crushed and sifted to obtain fermented cocoa placenta powder. The other part was not fermented but underwent the same steps to have an unfermented cocoa placenta powder. Standard and referenced methods have made it possible to measure certain functional properties of these cocoa placenta powders. Thus, the results showed that the fermentation increased the water absorption capacity (514.65%), the packed density (10.37g/mL), the clarity of the dough (2.13%) compared to to unfermented placenta powder which recorded rates of 496.50% for water absorption capacity, 9.34 g/mL for packed density and 1.86% for dough clarity. However, the solubility index of fermented cocoa placenta powder (15.45%) is lower than that of fermented powder (29.55%). These powders are able to easily disperse in water, giving a homogeneous solution. Moreover, the wettability value of unfermented cocoa placenta powder (4.09s) is higher than that of fermented powder (2.09s). Fermented cocoa placenta powder dissolves in water much faster than unfermented one. In addition, the oil absorption capacity (OAC) was higher in unfermented cocoa placenta powder with unrefined palm oil (270%). The functional properties of these flours have shown their importance for each measured parameter and can be useful in food technology processes for the formulation of foods, particularly in biscuits and bread making

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

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

Cross-sectional Study on Traditional Pork Rearing Practices and Cysticercosis in the South Part of Ivory Coast

Posted 24 Aug, 2020 on Research SquareInternational audienceIn West africa, pig meat know as pork is often supplied by traditional farms in rural areas. This pratice causes important sanitary risk by lack of veterinary control of farms and slaughterhouses in rural areas. The objective of this study was to describe pig husbandry practices used in southern Côte d'Ivoire in order to establish a surveillance system for cysticercosis disease. This survey was carried out among traditional pig breeders living in villages of the district of Dabou, Aboisso and Agboville. The data collected focused on the profile of producers and on the characteristics of the farms. A total of 321 breeders have been identified (Dabou 72 (22.4%), Aboisso 26 (8.1%) and Agboville 223 (69.5%)). Most of the herders were male (87.8%). A total of 3663 heads of pigs were counted with a majority of young pigs (60.2%) and females (29.3%) for 10.5% of male breeders. The local race was predominant (80.6 %) for only 15.5% of half-caste races. Most of the farms used permanent divagation rearing (53.3%). Following investigation of the herds, pigs were randomly samples in all the villages of the three areas using quota methods. Animals were blood sampled and serums were analyzed using Ac-ELISA and Western Blot. Among 639 animals selected, 13,20 % had antibodies against cysticercosis with large variations from one village to another. The study highlights that, in this region, pig farming remains essentially traditional, with free grazing of animals which constitutes a major sanitary risk especially for Taenia solium

Average number of spontaneous Rif^R and Nal^R mutants in colonies with various phage types.

<p>Average number of spontaneous Rif^R and Nal^R mutants in colonies with various phage types.</p

Pulsed Field Gel Electrophoresis patterns of 7 <i>Y</i>. <i>enterocolitica</i> 4/O:3 strains isolated from animals and humans.

<p>C: Control <i>Y</i>. <i>enterocolitica</i> 4/O:3 strain IP134, M: middle range molecular size marker, 1: IP35470; 2: IP35471; 3: IP35472; 4: IP35474; 5: IP35475; 6: IP35477; 7: IP35478.</p

Pair-wise analysis of SNPs among Ivorian <i>Y</i>. <i>enterocolitica</i> strains and an epidemiologically unrelated 4/O:3 isolate.

<p>Pair-wise analysis of SNPs among Ivorian <i>Y</i>. <i>enterocolitica</i> strains and an epidemiologically unrelated 4/O:3 isolate.</p

Minimal spanning tree of the <i>Y</i>. <i>enterocolitica</i> 4/O:3 strains isolated from pigs and humans in the Abidjan district.

<p>IP134 is a non-Ivorian <i>Y</i>. <i>enterocolitica</i> 4/O:3/VIII strain. Letters into brackets indicate the pig farm (A, B, C) or the human (H) origin of the strains.</p