328 research outputs found

    Analyse des attributs structurels de diversite en systeme forestier tropical, le cas de la foret classee de Sanaimbo en Côte d’Ivoire

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    L'étude synchronique des successions secondaires post-culturales en forêt dense semi-décidue (forêt classée de Sanaimbo ; Côte d'Ivoire) a été réalisée à partir des données obtenues sur 80 parcelles issues, respectivement de jachères post-culturales de 3 à 30 ans, de forêts exploitées pour le bois d'oeuvre et de forêts primaires non perturbées. La classification a permis d'identifier 14 groupes selon un gradient de maturité forestière. Les stades pionniers, très variables, étaient dominés par une espèce invasive comme Chromolaena odorata. Les analyses réalisées sur l'évolution de la composition floristique et des indices de diversité en utilisant l'âge et les facteurs mésologiques, montrent que, sous la dépendance de cesfacteurs, la succession secondaire s'accompagne d'une augmentation du nombre d'espèces et des attributs structurels de diversité.Mots clés : Successions secondaires, indices de diversité, type de végétation, forêt classée de Sanaimbo, Côte d'Ivoire

    Diversite floristique et valeur de conservation de la foret classee de Badenou (Korhogo, Cote d’Ivoire)

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    La prĂ©sente Ă©tude a Ă©tĂ© initiĂ©e pour contribuer Ă  la gestion durable de la forĂŞt classĂ©e de BadĂ©nou. Elle a permis d’analyser les diversitĂ©s  floristiques, la structure de la vĂ©gĂ©tation et d’estimer le stock de carbone sĂ©questrĂ© dans les diffĂ©rents biotopes le long d’une chronosĂ©quence de  stades postculturaux au sein d’un système de forĂŞt claire de CĂ´te d’Ivoire. Un total de 241 espèces a Ă©tĂ© recensĂ© dans l’ensemble du massif, dont 97 espèces (inventoriĂ©es dans les 30 parcelles) participent Ă  la chronosĂ©quence. Les 241 espèces Ă©taient rĂ©parties en 184 genres et 53 familles, dont les plus importantes Ă©taient les Fabaceae, les Rubiaceae et les Poaceae. La flore de cette aire protĂ©gĂ©e est aussi caractĂ©risĂ©e par la prĂ©sence des espèces Ă  statut particulier dont une endĂ©mique ivoirienne. Ces travaux montrent Ă©galement que les paramètres de composition et de structures des peuplements augmentent avec l’âge de la jachère. Le potentiel de stockage de carbone des diffĂ©rents biotopes rend compte de la participation de la forĂŞt classĂ©e de Badenou Ă  la rĂ©duction du CO2 atmosphĂ©rique dans cette rĂ©gion de la CĂ´te d’Ivoire. Malheureuse, la forĂŞt classĂ©e de  Badenou subit encore d’énormes pressions anthropiques. Les efforts de conservation des espèces endĂ©miques, rares et menacĂ©es d’extinction et de la forĂŞt classĂ©e elle-mĂŞme doivent ĂŞtre une prioritĂ©. Mots-clĂ©s : ForĂŞt claire, Jachères, BiodiversitĂ©, Changement climatique, Badenou English Title: Floristic diversity and conservation value of the Badenou Classified Forest (Korhogo, Cote dIivoire) This study was initiated to contribute to the sustainable management of the BadĂ©nou classified forest. It allowed to analyze the floristic diversities, the structure of the vegetation and estimate the carbon stock sequestered in the various biotopes along a chronosequence of post-cultural stages within a system of clear forest of Ivory Coast. A total of 241 species have been identified throughout the massif, of which 97 species (inventoried in the 30 plots) participate in the chronosequence. The 241 species were divided into 184 genus and 53 families, the most important of its were Fabaceae, Rubiaceae and Poaceae. The flora of this protected area is also characterized by the presence of special status species including an endemic Ivorian. This study also show that the parameters of stand composition and structure increase with the age of the fallow. The carbon  storage potential of the different biotopes accounts for the participation of the BadĂ©nou classified forest in the reduction of atmospheric CO2 in this region of Ivory Coast. Unfortunately, the BadĂ©nou classified forest is still under enormous human pressure. Conservation efforts for endemic  species, rare and endangered species and the classified forest itself must be a priority. Keys words: Clear forest, Fallows, Biodiversity, Climate change, Badeno

    Biodiversite vegetale et dynamique et reconstitution des jacheres post-culturales dans la foret classee d’Irobo (Sikensi, Cote d’Ivoire)

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    Nous analysons l’impact de l’agriculture traditionnelle sur la capacitĂ© de reconstitution dans une forĂŞt dense humide sempervirente non soumise Ă   des perturbations naturelles majeures. Des relevĂ©s de surfaces complĂ©tĂ©s par des relevĂ©s itinĂ©rants ont permis d’inventorier 448 espèces, qui se  rĂ©partissent en 301 genres et 92 familles, dont les plus importantes Ă©taient les Fabaceae, les Malvaceae, les Apocynaceae, les Euphorbiaceae, les Moraceae, les Rubiaceae, les Meliaceae et les Annonaceae. Parmi ces espèces, 32 (soit 7,14 % de l’effectif total) sont endĂ©miques Ouest africaines et deux (2) d’entre elles sont endĂ©miques ivoiriennes. La classification hiĂ©rarchique et l’ordination des 50 relevĂ©s de vĂ©gĂ©tation a permis d’identifier cinq (5) groupes s’agençant le long d’un gradient de maturitĂ© forestière. Les stades pionniers, très variables, Ă©taient dominĂ©s par une espèce  invasive : Chromolaena odorata (L.) R. King & H. Robinson. L’invasion prĂ©coce des champs par Chromolaena odorata. ne semble pas altĂ©rer  durablement la succession secondaire. Les plantations abandonnĂ©es se reconstituent pour atteindre le stade de forĂŞt secondaire, proche de la forĂŞt ancienne La forĂŞt prĂ©sente donc une bonne rĂ©silience. Mots clĂ©s : BiodiversitĂ© vĂ©gĂ©tale, Successions secondaires, ForĂŞt secondaire, Irobo, CĂ´te d’Ivoire   English title:Plant biodiversity and dynamics of regeneration in tropical rain forest (Irobo, Coted d’Ivoire) This study aims at testing whether shifting cultivation contribute to plant diversity in tropical rain forest. For hundred forty species have been  recorded in Irobo forest (CĂ´te d’Ivoire) during field investigations, distributed among 301 genera and 92 families, the most important being  Fabaceae, Malvaceae, Apocynaceae, Euphorbiaceae, Moraceae, Rubiaceae, Meliaceae and Annonaceae. Among those species, 33 (7.14%) are endemic from West Africa, among which only two are endemic from CĂ´te d’Ivoire. The hierarchical classification of 50 vegetation releves helped to identify 5 groups along a gradient of maturity. Early-successional stages were dominated by the invasive species Chromolaena odorata (L.) R. King & H. Robinson. The early invasion by Chromolaena odorata did not does not appear to alter secondary succession. Species assembled themselves into plant communities along the successional gradient with respect to their light requirements, suggesting niche partitioning. The succession progressively leads to a secondary forest similar to the primary forest. This forest is highly resilient. Key-words: Plant biodiversity, Secondary successions, Secondary forest, Irobo, CĂ´te d’Ivoir

    Small bowel stromal tumour revealed by a lower gastrointestinal bleeding

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    Small bowel stromal tumour must be systematically researched in the presence of obscure and persistent low gastrointestinal bleeding despite a normal endoscopic examination (OGDF and colonoscopy). Video capsule endoscopy is the best diagnosis examination; if it is not available a CT enterography could be useful. Surgical treatment is effective on localized and weak malignancy small bowel stromal tumours

    Effet antihypertensif d\'un extrait aqueux d\'écorce de tronc de Parkia biglobosa (mimosaceae) sur la pression artérielle de lapin.

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    Un extrait aqueux des écorces de tronc de Parkia biglobosa (EAPB), à des concentrations comprises entre 1,18 et 18, 93 mg/kg de poids corporel, induit une hypotension dose dépendante sur la pression artérielle de lapin. L'interaction Adrénaline - EAPB a révélé une réduction significative (

    Remotely Sensing the Biophysical Drivers of Sardinella aurita Variability in Ivorian Waters

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    The coastal regions of the Gulf of Guinea constitute one of the major marine ecosystems, producing essential living marine resources for the populations of Western Africa. In this region, the Ivorian continental shelf is under pressure from various anthropogenic sources, which have put the regional fish stocks, especially Sardinella aurita, the dominant pelagic species in Ivorian industrial fishery landings, under threat from overfishing. Here, we combine in situ observations of Sardinella aurita catch, temperature, and nutrient profiles, with remote-sensing ocean-color observations, and reanalysis data of wind and sea surface temperature, to investigate relationships between Sardinella aurita catch and oceanic primary producers (including biomass and phenology of phytoplankton), and between Sardinella aurita catch and environmental conditions (including upwelling index, and turbulent mixing). We show that variations in Sardinella aurita catch in the following year may be predicted, with a confidence of 78%, based on a bilinear model using only physical variables, and with a confidence of 40% when using only biological variables. However, the physics-based model alone is not sufficient to explain the mechanism driving the year-to-year variations in Sardinella aurita catch. Based on the analysis of the relationships between biological variables, we demonstrate that in the Ivorian continental shelf, during the study period 1998–2014, population dynamics of Sardinella aurita, and oceanic primary producers, may be controlled, mainly by top-down trophic interactions. Finally, based on the predictive models constructed here, we discuss how they can provide powerful tools to support evaluation and monitoring of fishing activity, which may help towards the development of a Fisheries Information and Management System

    Phytochemical composition, Antioxidant and Anti-inflammatory potential of bioactive fractions from extracts of three medicinal plants traditionally used to treat liver diseases in Burkina Faso

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    Our aim in this study concerning the ethyl acetate and dichloromethane fractions was to provide a scientific basis for the treatment of hepatitis B in Burkina Faso of these three ethnomedicinal plants. As a result, we evaluated polyphenol content, antioxidant and anti-inflammatory evaluated by lipoxygenase (LOX) inhibitory and Xanthine Oxidase (XO) activities of aqueous acetone bioactive fractions from three species of Malvaceae (Sida cordifolia, Sida rhombifolia, S. urens). Folin-ciocalteu; AlCl3 methods and tannic acid respectively were used for polyphenol content research. The antioxidant activity of the samples was evaluate using three separate methods, inhibition of free radical 2,2-diphenyl-1-picrylhydramzyl (DPPH), ABTS radical cation decolorization assay, Iron (III) to iron (II) reduction activity (FRAP). For anti-inflammatoty activity, lypoxygenase and xanthine oxidase inhibitory activities were used. Finally, in this study, the ethyl acetate fraction has shown the best results comparatively to the dichloromethane fraction. Keywords: Polyphenol, Antioxidant, anti-inflammatory, Medicinal plants, hepatitis B

    Phytochemical composition, Antioxidant and Anti-inflammatory potential of bioactive fractions from extracts of three medicinal plants traditionally used to treat liver diseases in Burkina Faso

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    Our aim in this study concerning the ethyl acetate and dichloromethane fractions was to provide a scientific basis for the treatment of hepatitis B in Burkina Faso of these three ethnomedicinal plants. As a result, we evaluated polyphenol content, antioxidant and anti-inflammatory evaluated by lipoxygenase (LOX) inhibitory and Xanthine Oxidase (XO) activities of aqueous acetone bioactive fractions from three species of Malvaceae (Sida cordifolia, Sida rhombifolia, S. urens). Folin-ciocalteu; AlCl3 methods and tannic acid respectively were used for polyphenol content research. The antioxidant activity of the samples was evaluate using three separate methods, inhibition of free radical 2,2-diphenyl-1-picrylhydramzyl (DPPH), ABTS radical cation decolorization assay, Iron (III) to iron (II) reduction activity (FRAP). For anti-inflammatoty activity, lypoxygenase and xanthine oxidase inhibitory activities were used. Finally, in this study, the ethyl acetate fraction has shown the best results comparatively to the dichloromethane fraction. Keywords: Polyphenol, Antioxidant, anti-inflammatory, Medicinal plants, hepatitis B

    Effet de la race de l'hémicastration et de la FSH sur la population folliculaire ovarienne chez les agnelles

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    Utilisant la méthode histologique quantitative de l'ovaire, on a comparé l'effet race, hémicastration et traitement avec FSH après hémicastration chez l'agnelle âgée de 15 jours de deux races différant par leur taux d'ovulation: D'man (haute prolificité), Timahdite (basse prolificité). Le nombre et la distribution des follicules ovariens ne difIèrent pas significativement entre les deux races à l'âge de 15 jours et l'hémicastration n'a pas d'effet à courtterme sur la population des follicIes ovariens et sur la concentration de FSH. La concentration de FSH augmente après hémicastration et injection de FSH. Le nombre des follicules primordiaux (avec une couche de cellules cubiques) augmente après traitement avec FSH, Le nombre de follicules à antrum est doublé et l'atrésie est réduite de moitié chez les deux races. La race prolifique (D'man) montre une sensibilité à la stimulation par FSH plus marquée que chez la race non-prolifique (Timahdite)
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