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Study of the Biological Quality of the Water in the Manantali Dam Reservoir: Analysis of the Fish Fauna and Plankton Communities

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Journal of Agricultural Chemistry and Environment 2024年第1期13卷 100-114页

作者： Joseph Mbeur Faye Saïdou Ndao louis eugène victor sambou Laboratory of Water and Environment Sciences and Technologies (LaSTEE) Polytechnic School of Thies (EPT) Thies Senegal UFR Sciences et Technologies (SET) University Iba Der Thiam of Thies (UIDT) Thies Senegal

The aim of this study of the Manantali dam reservoir is to investigate the biological quality of the water through inventories and analysis of the ichthyofauna and planktonic communities (zooplankton and phytoplankton). Inventories of ichthyofauna and plankton communities were carried out quarterly from 2003 to 2022. The fish populations studied on the basis of bioindicators (species richness, diversity index, equitability index, diversification index) identified 29 species belonging to 10 families. The Cichlidae family is the most represented, while the Schilbeidae and Tetraodontioae families are less represented in terms of number of species. The species Hydrocynus forskalii and Brycinus nurse with relative abundances of 40.12% and 21.4% respectively, both from the family Alestidae, are the most abundant. The species H. forskalii has a frequency of occurrence of 100%. The specific diversity index of 2.9 and the equitability index of 0.6 show an average diversity of fish species. The diversification index of 2.9 indicates a theoretical number of habitats of 2 to 3. The planktonic community is made up of zooplankton and phytoplankton. The inventory of zooplankton shows the presence of 28 zooplankton species belonging to 9 families of the three zooplankton groups Rotifera, Cladocera and Copepoda. Analysis of the frequencies of occurrence of the various taxa showed that the characteristic species of Lake Manantali are the omnipresent rotifers Keratella cochlearis, Keratella quadrata and Trichocerca chattoni. For phytoplankton, the inventories carried out show the presence of 65 species belonging to 5 families (Chlorophycees, Diatomees, Dinophycees, Chrysophycees and Cyanophycees). An analysis of the frequency of occurrence of the various taxa shows that the characteristic species of Lake Manantali are Chlorophycees, with 7 species: Desmidium baileyi, Micrasterias alata, Sphaerocystis schroeteri, Spondylosium sp., Staurastrum heimii, Staurastrum subanchora, Staurodesmu

关键词： Inventory Fish Zooplankton Phytoplankton Diversity Manantali

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Evolution of the Physico-Chemical Quality of the Water in the Manantali Dam Reservoir from 1989 (One Year after Impoundment) to 2022

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Journal of Geoscience and Environment Protection 2023年第9期11卷 351-366页

作者： Joseph Mbeur Faye Saïdou Ndao louis eugène victor sambou Laboratory of Water and Environment Sciences and Technologies (LaSTEE) Polytechnic School of Thies (EPT) Thies Senegal UFR Sciences and Technologies (SET) University Iba Der Thiam of Thies (UIDT) Thies Senegal

The Manantali dam is located on the Bafing River in the Kayes region of Mali. It is the main tributary of the Senegal River. The water released from the dam provides year-round access to water for drinking, irrigation and livestock watering. The Manantali dam regulates the river’s flow, generates energy and supports agricultural development in all three countries (Mali, Mauritania, and Senegal). The aim of this article is to monitor changes in the physico-chemical quality of the water in the dam’s reservoir from 1989 (one year after the dam was impounded) to 2022. In order to carry out this work, we analysed the evolution of physico-chemical parameters in Stations 1 and 3 of the dam, on the basis of fluctuating water levels in the reservoir. The results obtained show a similarity in the parameters measured at the two stations, except for iron content, which is higher at Station 3. The average pH is weakly basic (7.44 at Station 1 and 7.29 at Station 3) and the average water temperature is between 26.5°C at Station 1 and 26.2°C at Station 3. The average conductivity of the water at Station 1 is 38.8 μS/cm and 39.8 μS/cm at Station 3, attesting to low mineralization of the water. The oxygen content of 5.75 mg/L at Station 1 and 5.00 mg/L at Station 3 shows good oxygenation of the water, which is favorable for the development of most fish and aquatic plant species. Ammonium levels of 0.02 mg/L at Station 1 and 0.06 mg/L at Station 3 show that the water is not contaminated. In addition, the Water Quality Index (WQI) was calculated, showing excellent water quality at Station 1 and good quality at Station 3. Overall, the results obtained show that the water is of good quality, enabling the authorities of the Organization for the Development of the Senegal River (OMVS) to achieve their development objectives.

关键词： OMVS WQI Senegal River Physicochemical Parameters

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Physical Characterization and Evaluation of the Water Potential of the Watershed of the Ferlo Fossil Valley, Senegal: Louga Area

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Open Journal of Modern Hydrology 2023年第4期13卷 181-192页

作者： louis eugène victor sambou Saïdou Ndao Papa Babacar Diop Thioune Laboratory of Water and Environment Sciences and Technologies l’Environnement (LaSTEE) Polytechnic School of Thies (EPT) Thies Senegal UFR Sciences et Technologies (SET) University Iba Der Thiam of Thies (UIDT) Thies Senegal Higher Institute of Agricultural and Rural Training (ISFAR) University Alioune Diop of Bambey (UADB) Bambey Senegal

This study is an evaluation of the water potential of the Ferlo fossil valley in the Louga area in Senegal. It consisted in determining the volume of water that could be mobilized at the level of a confluence point of the waters according to the flow lines, where a dam would be placed to create a reservoir. This volume of mobilizable water was compared to the average water consumption of the area in order to evaluate its adequacy or not. To do this, a delineation, physical characterization and mapping of the Ferlo watershed was done using Google Earth, Global Mapper and Arc GIS softwares. A catchment area of 28,754 sq·km was obtained with a perimeter of 976 km, an average slope of 0.52% and a hydraulic length of 336 km. Then the decennial runoff of the watershed was calculated using the CIEH method, this flow is estimated at 1120 cm/s. On the basis of this flow, the annual volume of water that can be mobilized was estimated at 11,089,758 cm per year with a solid deposits of 93 cm per year. The conclusions reached are that there is a lack of mobilizable water resources in the area and that the entire fossil valley needs to be rewatered to provide a sustainable alternative water source.

关键词： Ferlo Fossil Valley Watershed Dam Water Resources Revitalization

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Floristic Diversity and Conservation Status of Guineo-Congolese Species in Southeastern Cameroon: The Case of the Gari-Gombo Communal Forest

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Open Journal of Forestry 2024年第1期14卷 87-97页

作者： Boris Nyeck Valery Noiha Noumi Nicole Maffo Maffo victor Awe Djongmo Cedric Djomo Chimi louis Zapfack Department of Biological Sciences Faculty of Sciences University of Ngaoundéré Ngaoundéré Cameroon Agricultural Research Institute for Development (IRAD) Minko Agricultural Research Station Meyomessala Cameroon Department of live Sciences Higher Teacher Training College University of Bertoua Bertoua Cameroon Department of Plant Biology and Physiology Faculty of Sciences University of Yaoundé I Yaoundé Cameroon Agricultural Research Institute for Development (IRAD) Research Station of Yokadouma Yokadouma Cameroon

The conservation of plant biodiversity has become one of the most important objectives in the sustainable management of Guinean-Congolese ecosystems. However, in the south-east zone of Cameroon, there is a lack of rigor in the management of these forests, which can result in the loss of species of high conservation value. The study was carried out in communal forests in the south-east zone of Cameroon. Its aim was to carry out a floristic inventory and then compare the list of species with the IUCN catalog. Twenty-four plots, each with a surface area of 0.2 ha, were set up in the Gari-Gombo communal forest. All timbers with a DBH ≥ 5 cm were systematically counted. A total of 176 species, belonging to 144 genera and 45 families, were surveyed. Fabaceae (42.08%), Malvaceae (39%), Euphorbiaceae (24.64%), Moraceae (20.92%), Apocynaceae (18.64%), Cecropiaceae (16.60%), Ulmaceae (14.76%), Meliaceae (14.61%), Violaceae (14.08%), Combretaceae (12.67%), Theobroma cacao (21.17%), Baphia leptobotrys (18.06%), Rinorea sp. (14.09%), Musanga cecropioides (12.18%), Terminalia superba (10.32%), neosloetiopsis kamerunensis (10.14%), Celtis zenkeri (8.29%) and Alstonia boonei (7.77%) were the most important taxa. nearly 90% of the species in this forest are Guinean species, with a dominance of Guinean-Congolese species (66%). Fourteen (14) threatened species have been identified in the FCGG. This study, which highlights the rich biodiversity of communal forests, is important for guiding biodiversity conservation policies in ecosystems used for production.

关键词： Communal Forest Conservation Status Cameroon Floristic Diversity

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Interpretation of Geological and Gravity Data from the Bamiléké Plateau (West-Cameroon): Implication for the Understanding of Its Underground Lithotectonic Geometry

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Journal of Geoscience and Environment Protection 2024年第9期12卷 283-314页

作者： louis Christian Kamgang Chendjou Jean victor Kenfack Jules Tcheumenak Kouémo Fidèle Koumetio Armand Kagou Dongmo Department of Earth Sciences Faculty of Science University of Dschang Dschang Cameroon Department of Earth Sciences Faculty of Sciences University of Douala Douala Cameroon Department of Physics Faculty of Sciences University of Dschang Dschang Cameroon

The Bamiléké Plateau represents a key domain in the understanding of the geodynamics associated with the central Cameroon shear. The study aimed to highlight the subsurface architecture of the plateaus basement setting with focus on high potential areas for hydrogeological and mining development projects. To this end, geological field observations were carried out. Since the structures sought were near-surface, a separation approach based on the upward continuation method was applied to the Bouguer anomaly grid. A set of processing techniques, including vertical derivative or DZ, analytical signal or SA and categorization of gravity signatures, was applied to generate the residual map. The synthesis geological model, obtained from analysis and interpretation of the various transformed maps and 2.5D modeling of two gravity profiles P1 and P2 highlights the following features: 1) intrusions of steep-sided granitic batholiths from Dschang to Bandjoun (profile P1), increasing in width from NW (Dschang) to SE (Bandjoun);2) larger volume batholiths with moderate sides located at Bafang and Bangangté (profile P1). These plutonic massifs were weakened by brittle deformation, which favored the emplacement of phonolite or anorthosite dykes within them. The emplacement of these dykes was accompanied by compressional faults with high dip between Dschang and Bandjoun and extensional faults with medium dip between Bafang and Bangangté. These fault zones (trending N85E to N95E) are ideal for hydrogeological investigations in a basement setting, as well as a series of dyke networks that could potentially be preferred zones for the circulation and accumulation of useful substances. The resulting geological sections P1 and P2 highlight the influence of granitic intrusions in the geological system of the study area, as well as the structural control associated with the various dyke intrusions. All the models obtained can serve as fundamental references for hydrogeological and mining e

关键词： Bamiléké Plateau Gravity Measurement Gravity Anomalies Lineaments

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Floristic Diversity and Conservation Status of Guineo-Congolese Species in Southeastern Cameroon: The Case of the Gari-Gombo Communal Forest

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Open Journal of Forestry（林学期刊） 2024年第1期

作者： Boris Nyeck Valery Noiha Noumi Nicole Maffo Maffo victor Awe Djongmo Cedric Djomo Chimi louis Zapfack

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Theoretical study of defect impact on two-dimensional MoS_2

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Journal of Semiconductors 2015年第12期36卷 18-23页

作者： Anna V.Krivosheeva victor L.Shaposhnikov victor E.Borisenko Jean-louis Lazzari Chow Waileong Julia Gusakova Beng Kang Tay Belarusian State University of Informatics and Radioelectronics CNRS Aix-Marseille Université NOVITAS Nanoelectronics Centre of Excellence School of Electrical and Electronic Engineering Nanyang Technological University CINTRA CNRS NTUTHALES Nanyang Technological University

Our theoretical findings demonstrate for the first time a possibility of band-gap engineering of monolayer MoS2 crystals by oxygen and the presence of vacancies. Oxygen atoms are revealed to substitute sulfur ones, forming stable MoS2-xOx ternary compounds, or adsorb on top of the sulfur atoms. The substituting oxygen provides a decrease of the band gap from 1.86 to 1.64 eV and transforms the material from a direct-gap to an indirect-gap semiconductor. The surface adsorbed oxygen atoms decrease the band gap up to 0.98 eV depending on their location tending to the metallic character of the electron energy bands at a high concentration of the adsorbed atoms. Oxygen plasma processing is proposed as an effective technology for such band-gap modifications.

关键词： two-dimensional crystal molybdenum disulfide band gap vacancy oxygen

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Preoperative rectosigmoid endoscopic ultrasonography predicts the need for bowel resection in endometriosis

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World Journal of Gastroenterology 2019年第6期25卷 696-706页

作者： victor Desplats René-louis Vitte Joseph du Cheyron Gilles Roseau Arnaud Fauconnier Frédérick Moryoussef Department of Hepato-gastroenterology Centre Hospitalier Intercommunal Poissy Saint Germain Department of Statistics Centre Hospitalier Intercommunal Poissy Saint Germain Department of Gastroenterology H?pital Cochin Department of Obstetrics and Gynecology Centre Hospitalier Intercommunal Poissy Saint Germain University of Saint Quentin en Yvelines

BACKGROUND Rectosigmoid endometriosis is an underdiagnosed disease responsible for abdominal pain, transit disorders and rectal bleeding. Two surgical approaches,rectosigmoid bowel resection(segmental or patch) or intramuscular layer dissection(shaving), are *** To assess whether the lesion features observed via preoperative rectosigmoid endoscopic ultrasonography(RS-EUS) might predict the need for bowel *** This multicentric retrospective study was conducted on patients with rectosigmoid endometriosis who underwent a curative surgical procedure,evaluated by RS-EUS performed by two trained operators, between January 2012 and March 2018. A univariate statistical analysis was performed on nodules' RSEUS features(thickness, width, infiltration of the submucosae, presence of a bump into the digestive lumen and presence of multiple rectosigmoid localizations). A multivariate logistic regression was then performed on the significant *** Of the 367 patients, 73 patients with rectosigmoid endometriosis were evaluated by RS-EUS and underwent rectosigmoid surgery. After the univariate analysis was completed, thickness, width and infiltration of the submucosae were identified as potential predictive factors for bowel resection. In a multivariate logistic regression model, only thickness appeared to be a significant [odds ratio(OR) = 1.49, 95% confidence interval(CI): 1.04-2.12, P = 0.028] predictive factor for bowel resection. Receiver operating characteristic analysis performed showed that a thickness over 5.20 mm might be used as cut-off with a sensitivity of 76%, a specificity of 81%, and an area under carve = 0.82. The cut-off values for 100%sensitivity and 100% specificity were 0.90 mm and 10.00 mm, respectively. A trend concerning width to predict the need for resection was also observed(OR1.12, 95%CI: 1.00-1.26, P = 0.054)CONCLUSION The presence of a rectosigmoid nodule of endometriosis greater than 5.20 mm thick on RS-EUS might predi

关键词： Endometriosis Surgery Endoscopy Ultrasound Bowel disease Rectum and sigmoid

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Isobavachalcone:An Overview

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Chinese Journal of Integrative Medicine 2012年第7期18卷 543-547页

作者： victor Kuete louis P.Sandjo Department of Biochemistry Faculty of ScienceUniversity of Dschang Department of Organic Chemistry Faculty of ScienceUniversity of Yaounde Ⅰ

Isobavachalcone （IBC） or （E）-l-[2,4-dihydroxy-3-（3-methyl-2-butenyl）-phenyl]-3-（4- hydroxyphenyl）-2-propen-1-one or （E）-4,2＇,4＇-trihydroxy-3＇-prenylchalcone; 2＇,4,4＇-trihydroxy-3＇-prenyl-trans- chalcone, is a prenylated chalcone of the class flavonoid, firstly isolated from Psoralea corylifolia in 1968. IBC is known to possess a wide spectrum of biological activities, antibacterial, antifungal, anticancer, anti-reverse transcriptase, antitubercular and antioxidant. The compound was isolated from plant families, mostly Moraceae and Fabaceae. This review brings out together the knowledge on IBC, and can serve as the start point for future research and valorization accomplishments.

关键词： Isobavachalcone pharmacology biosynthesis synthesis

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Theoretical study of defect impact on two-dimensional MoS

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Journal of Semiconductors 2015年第12期 22-27页

Our theoretical findings demonstrate for the first time a possibility of band-gap engineering of monolayer MoS;crystals by oxygen and the presence of vacancies. Oxygen atoms are revealed to substitute sulfur ones, forming stable MoS;O;ternary compounds, or adsorb on top of the sulfur atoms. The substituting oxygen provides a decrease of the band gap from 1.86 to 1.64 eV and transforms the material from a direct-gap to an indirect-gap semiconductor. The surface adsorbed oxygen atoms decrease the band gap up to 0.98 eV depending on their location tending to the metallic character of the electron energy bands at a high concentration of the adsorbed atoms. Oxygen plasma processing is proposed as an effective technology for such band-gap modifications.

关键词： two-dimensional crystal molybdenum disulfide band gap vacancy oxygen

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