167 research outputs found

    CaractĂ©risation litho stratigraphique et petro-sedimentologique des formations tertiaire-quaternaires de la rĂ©gion de Bingerville (CĂŽte d’Ivoire)

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    La caractĂ©risation litho stratigraphiques et pĂ©tro-sĂ©dimentologiques contribue Ă  prĂ©ciser les faciĂšs lithologiques ainsi que leur minĂ©ralogie et Ă  mieux cerner les sĂ©quences sĂ©dimentaires de la rĂ©gion de Bingerville. La caractĂ©risation litho stratigraphique rĂ©vĂšle la prĂ©sence d’argile noire surmontĂ©e par de l’argile bariolĂ©e d’ñge Mio-pliocĂšne. Des dĂ©pĂŽts plus rĂ©cents recouvrent l’argile bariolĂ©e. Ils sont constituĂ©s de sables, de sables micro conglomĂ©ratiques, de sables argileux ocre, d’argiles sableuses, de grĂšs ferromanganeux, de stone line et de terre de barre. Ces dĂ©pĂŽts comblent des palĂ©o chenaux de types anastomosĂ©s. La caractĂ©risation pĂ©tro-sĂ©dimentologique rĂ©vĂšle la prĂ©sence de certains minĂ©raux tels que : quartz, hĂ©matite, biotite, sillimanite, scheelite, goethite, limonite, manganĂšse, pyroxĂšne et tourmaline. Les grĂšs auraient un ciment hĂ©mato-manganeux. Aussi, les sables sont moyennement classĂ©s. Ces sables ont Ă©tĂ© transportĂ©s par saltation et dĂ©posĂ©s par dĂ©cantation dans un environnement fluviatile loin de leur source pourvoyeuse.Mots-clĂ©s : hĂ©mato-manganeux, litho stratigraphique, mio-pliocĂšne, plio-quaternaire, pĂ©tro-sĂ©dimentologiques

    Spéciation chimique des éléments traces métalliques dans un environnement lagunaire confiné: La baie de Bietry

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    L’analyse des concentrations métalliques déterminées pour les sédiments de la baie de Biétry a permis d’évaluer le niveau de pollution. Les métaux non pollués (classe 0 et 1) sont : Th, Co, V, Ni, Ag et Sb, avec des proportions qui varient de 55 à 70%. Les métaux pollués (classes 2, 3, 5, 6) présentent des proportions variant de 100 à 70%. Il s’agit de Cr, Mo, As, U, Pb, Cd, Zn et Cu. Les résultats des extractions sélectives effectuées ont permis de déterminer le potentiel de mobilité et de disponibilité biologique de ces ETM (Eléments Traces Métalliques) polluants. Ainsi le gradient de biodisponibilité dans la baie de Biétry s’établit comme suit: Ni>Co>Zn et dans une moindre mesure V>Cu>As>Th>Mo>Pb>Sb. Dans les phases porteuses des ETM, la fraction résiduelle est la plus dominante pour tous les métaux à l’exception de Zn et Mo. Du polluant le plus mobile au moins mobile, nous avons obtenu l’ordre suivant: Zn, Ni, Pb, Co, Th, Mo, As, Sb, Cr.Mots clés: Igeo, pollution, biodisponibilité, spéciation métalliqu

    Morphodynamisme des environnements Ă  Beach-rocks du plateau continental de CĂŽte d’Ivoire (golfe de GuinĂ©e)

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    Les beach-rocks sont constituĂ©es de grains de quartz, avec une faible proportion de feldspath et de mica. Il s’agit de grĂšs quartzeux Ă  cimentferrugineux, parfois carbonatĂ©s. Ils sont constituĂ©s de matĂ©riaux terrigĂšnes charriĂ©s par les cours d’eau. Ces grĂšs ont subi un long transport et une cimentation par prĂ©cipitation de l’oxyde de fer. L’absence de fraction argileuse, la faible proportion de feldspaths et de micas, et l’abondance de quartz Ă  grains arrondis indiquent qu’ils sont matures. Eneffet, la prĂ©sence de quartzs polycristallins indiquant une recristallisation et une substitution du ciment, montre que ces grĂšs ont subi une diagenĂšse avancĂ©e. La fraction sableuse adjacente aux barres de grĂšsdu plateau continental montre des sables d’origine fluviatile, mal triĂ©s Ă  classement mĂ©diocre prĂ©sentent une asymĂ©trie vers les plus petites tailles. Ces grĂšs se dĂ©poseraient dans un environnement de type ligne derivage, sous l’influence de courants locaux bimodaux dus aux variations du niveau de la mer. En raison de leur rĂ©sistance mĂ©canique et de leurĂ©paisseur, les beach-rocks constituent un obstacle au transport dessĂ©diments.Mots-clĂ©s : Beach-rocks, sĂ©dimentologie, palĂ©oenvironnement, plateau continental, CĂŽte d’Ivoir

    Model Infiltrasi pada Berbagai Penggunaan Lahan di Desa Tulo Kecamatan Dolo Kabupaten Sigi

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    This study aims to determine the model of infiltration at a variety of land uses (land palm plantations, cocoa plantation land, wetland and shrub land) in the village of Tulo, District Dolo, Sigi. Data analysis infiltration rate equation model Horton. Infiltration rate measurements in the field using a double ring infiltrometer are embedded into the ground and then ring in the contents above water until the boundary line. Observation of decreased water level in measuring each interval of 10, 20,30,40,50,60 minutes. Measurement of infiltration repeated three times for each land use. The results showed that the model of infiltration in oil plantation area that is f = 8,2 + (10 – 8,2) e-2,64t, on a cocoa plantation land is f = 8 + (10 - 8) e-2,68t, in paddy fields, namely f = 9,23 + (10 – 9,23) e-5,20t and the shrub land is f = 4 + (10 - 4) e-2,96t. Infiltration in the shrub land quite a bit faster in the amount of 6,56 cm/hour, on a cocoa plantation land classified as being in the amount of 2,06 cm/hour, on a coconut plantation land and wetland quite a bit slower with the infiltration rate of the soil palm plantations amounted to 1,87 cm/hour and a wetland of 0,87 cm/hour

    Degradasi Beberapa Sifat Fisik Tanah Akibat Alih Guna Lahan Hutan Menjadi Lahan Perkebunan Kakao (Theobroma Cacao L.) Di Desa Sejahtera, Palolo

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    Research has been conducted to determine some physical soilproperties degradation due to land use change of forest land into plantations of cacao ( Theobroma cacao L. ) in Sejahtera village. The method used in this study was using the survey method. The observations and soil sampling location determined by purposive sampling technique such as observation and soil sampling location determined based on the researcher's consideration on soil conditions, slope, land use domination and the age of cocoa contained in the study area. The results shown that there has been a decrease in land capacity because of land use change of forest into cocoa plantations, which forest land has physical characteristics of the soil with a sandy loam texture , permeability classified as moderate , high bulk density, saturated soil water content is quite good, as well as relatively good porosity, whereas cocoa land has physical characteristics with sandy clay loam texture, relatively little slow permeability, high bulk density, saturated soil water content is quite good, as well as the relatively poor porosity

    Assessing the severity and the incidence of Cassava Root Necrosis Disease (CRND) in western Democratic Republic of Congo

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    Open Access ArticleCassava is the staple food in the Democratic Republic of Congo (DRC) where both the roots and leaves are consumed. This crop is susceptible to several viral diseases, including Cassava Mosaic Disease(CMD) and Cassava Brown Streak Disease(CBSD) in eastern DRC. Following earlier studies that show root necrosis occurring in western DR Care not due to CBSD but to Cassava Root Necrosis Disease (CRND), an exploratory survey was conducted in western DRC from 2016 to 2017 in order to determine the distribution, the severity and the incidence of this disease (previously known as CBSD-like disease). NGS ( Next Generation Sequencing) results confirmed all the previous negative results obtained using PCR and CBSV primers. This suggests that microorganisms such as bacteria or fungi could be responsible for cassava root necrosis in western DRC and is not CBSD as predicted. Five provinces (Bas-Congo, Kinshasa, Bandundu, Equateur and Kasai-Oriental) were surveyed and data were collected according to the harmonized protocols adopted by countries within the West African Virus Epidemiology (WAVE) project. Statistical tests (ANOVA) performed on our data showed that CRND severity did not vary significantly among the provinces of Kinshasa, Bandundu and Bas-Congo which are the areas most affected by the disease. Bas-Congo and Kinshasa provinces presented the highest maximum disease severity (score 3 and 5 respectively), while Equateur province had the lowest disease severity score. Equateur province also had the highest percentage of healthy plants and few plants presented mild symptoms. The overall average of cassava root necrosis severity in western DRC ranged around 1.88 ± 0.08, an approximate score of 2. The overall mean incidence of CRND in western DRC was 22.24 ± 2.4% but reached 100% in localities considered as hotspots (Lukuakua in Bas-Congo and Nguma in Plateau des Batékés). The behaviour of cassava varieties against CRND is similar with CBSD in East Africa, most of improved varieties and landraces are susceptible to both diseases. Correlation analyses showed a positive correlation (r = 0.6940) between severity and incidence of CRND. Therefore, Bas-Congo province is the most affected province, while the province of Equateur is the least affected province in western DRC. Further investigations, including genomic surveillance, should also be conducted in the eastern DRC where CBSD is confirmed to know if CRND is found in conjunction with CBSD and to report possible instances of mixed infections. For medium-term disease control, our study suggests that the development and deployment of control measures including cultivars with resistance to CRND and CBSD should be a priority

    Hydrologie et morphologie de l’estuaire du fleuve Sassandra, Basse Cîte d’Ivoire

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    Les Ă©tudes physico-chimiques des eaux de surface et de sub-surface et les levĂ©s bathymĂ©triques effectuĂ©s dans l’estuaire du fleuve Sassandra, ont permis de caractĂ©riser l’hydrologie et la morphologie du fond de cet embouchure. Sur toute la surface d’eau le pH est proche de la neutralitĂ©, la conductivitĂ© est comprise entre 50 et 200ÎŒs/cm, avec une tempĂ©rature moyenne de 28,91°C. La salinitĂ© de l’estuaire augmente au fur et Ă  mesure que l’on s’approche de l’ocĂ©an Atlantique. Sa valeur est comprise entre 0 et 4%. Le taux d’oxygĂšne, trĂšs faible Ă  l’embouchure avec une valeur de 2 mg /L contre 8,30 mg/L dans la branche droite du fleuve couverte par la vĂ©gĂ©tation. Les MatiĂšres En Suspension (MES) analysĂ©es sont constituĂ©es d’une fraction inorganique de quartz, feldspath, amphibole, mica, argiles, etc...et d’une fraction organique constituĂ©e de dĂ©bris animaux et vĂ©gĂ©taux. Cette Ă©tude a permis de rĂ©aliser les cartes bathymĂ©triques et la rĂ©partition des paramĂštres physico-chimiques, ainsi que la dĂ©termination des dĂ©pressions et les processus d’érosions au fond de l’estuaire du fleuve Sassandra.Mots-clĂ©s: hydrologie, bathymĂ©trie, paramĂštres physico-chimiques, fleuve Sassandra, CĂŽte d’Ivoire. Hydrology and morphology of the estuary of the Sassandrariver (Low CĂŽte d’Ivoire) The physico-chemical studies of waters of surface and sub-surface and the bathymetric sunrises made in the estuary of theSassandrariver, allowed to characterize the hydrology and the morphology of the bottom of this mouth. On all the surface of water the pH is close to the neutrality, the conductivity is between 50 and 200ÎŒs/cm, with an average temperature of 28,91°C. The salinity of the estuary increases as we approach the Atlantic Ocean. His value is between 0 and 4%. The rate of oxygen, very low in the mouth with a value of 2 mg / L against 8,30 mg / L in the straight branch of the river covered by the vegetation. Suspension materials (MES) analyzed are constituted by an inorganic fraction of quartz, feldspar, amphibole, mica and clays etc. and of an organic fraction constituted by animal and plant fragments. This study allowed to realize the bathymetric maps and the distribution of the physico-chemical parameters, as well as the determination of the depressions and the processes of erosions at the bottom of the estuary of the Sassandra river.Keywords: hydrology, bathymetry, physico-chemical parameters, Sassandra river, CĂŽte d’Ivoire

    Effet antibiose de quatre cultivars de bananier et bananiers plantains sur Cosmopolites sordidus Germar (Coleoptera: Curculionidae) Ă  Kisangani, RD Congo

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    Black weevil (Cosmopolites sordidus Germar) development on bananas and plantains (Musa sp.) was assessed on four cultivars named: Libanga likale (AAB), Litete (AAB), Lokusu (AAB) and Yangambi Km5 (AAA). Rearing black weevil with Litete cultivar has shown better insect growth larvae expressed from most of parameters such as larvae number (31), adults emergency frequency (26.6), larvae's mortality rate (14.1%) and post-larvae development cycle (30 to 34 days) compared to Yangambi (9.3 larvae). Therefore, black weevil showed good response on plantains cultivars. Sex ratio (male: female) was either for among plantains cultivars but highly influenced from Yangambi Km5 with 1.8:1. Yangambi Km5 antibiosis showed high larvae mortality rate of 63.67%, weak emergency rate (28) and long post-larvae development of 50 days. This shows that the cultivar 'Litete' was the most susceptible to weevils. Keys words: banana, Musa cultivars, weevils, emergency, development cycleLe dĂ©veloppement du charançon noir (Cosmopolites sordidus Germar) des bananiers et bananiers plantains (Musa sp.) a Ă©tĂ© Ă©valuĂ© sur quatre cultivars: Libanga likale (Musa AAB), Litete (Musa AAB), Lokusu (Musa AAB) et Yangambi Km5 (Musa AAA). Le charançon noir Ă©levĂ© sur le cultivar Litete a montrĂ© une meilleure croissance exprimĂ©e dans la plupart des paramĂštres comme le nombre de larves (31), la frĂ©quence d’émergence des adultes (26.6), le taux de mortalitĂ© larvaire (14,1%) ainsi que la longueur du cycle de dĂ©veloppement post-larvaire (30 Ă  34 jours). Le charançon noir s’y dĂ©veloppe plus vite et plus nombreux. Le ratio sexuel est similaire chez les cultivars de bananiers plantains mais fortement influencĂ© chez Yangambi Km5 oĂč il est de 1,8 :1. L’antibiose de Yangambi Km5 se manifeste par un taux de mortalitĂ© larvaire Ă©levĂ© de 62.8%, faible taux d’émergence des adultes (9.3) et un cycle de dĂ©veloppement post-larvaire plus long (50 jours) et un ratio sexuel dĂ©sĂ©quilibrĂ©. Ceci montre que le cultivar Litete est le plus sensible aux charançons par rapport aux cultivars Ă©tudiĂ©s. MOTS-CLEFS: bananier, Musa, cultivars, charançons, Ă©mergence, cycle de dĂ©veloppemen

    DINAMIKA KARBON (C) AKIBAT ALIH GUNA LAHAN HUTAN MENJADI LAHAN PERTANIAN

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    Land use changes from forest to agricultural farms have been incessantly occurring in Indonesia. This condition will have harmful effects on nature equilibrium if uncontrolled. Forest can effectively absorbed carbon, in contrast deforestation will result in the release of carbon dioxide (CO2) to the atmosphere. The research results indicated that significant carbon losses have taken place due to forest changes to agricultural farms.  Agro-forestry system can lessen these losses from vegetation, litter, soil and due to soil erosion. Agricultural farm with maize and peanut produced lower carbon than forest and vanilla agro-forestry

    Glycoconjugate Data Bank:Structures—an annotated glycan structure database and N-glycan primary structure verification service

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    Glycobiology has been brought to public attention as a frontier in the post-genomic era. Structural information about glycans has been accumulating in the Protein Data Bank (PDB) for years. It has been recognized, however, that there are many questionable glycan models in the PDB. A tool for verifying the primary structures of glycan 3D structures is evidently required, yet there have been no such publicly available tools. The Glycoconjugate Data Bank:Structures (GDB:Structures, http://www.glycostructures.jp) is an annotated glycan structure database, which also provides an N-glycan primary structure (or glycoform) verification service. All the glycan 3D structures are detected and annotated by an in-house program named ‘getCARBO’. When an N-glycan is detected in a query coordinate by getCARBO, the primary structure of the glycan is compared with the most similar entry in the glycan primary structure database (KEGG GLYCAN), and unmatched substructure(s) are indicated if observed. The results of getCARBO are stored and presented in GDB:Structures
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