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Acta Geochimica 2023年第6期42卷 1017-1034页

作者： Simon Pierre Mbola Ndzana Moise Christian Balla Ateba germain marie monespérance mboudou Moussa Nsangou Ngapna Jean Paul Sep Nlongang Solange Ipan Moise Bessong Jean Bosco Olinga Joseph Mvondo Ondoa Sébastien Owona Paul Bilong Department of Earth Sciences Faculty of ScienceUniversity of YaoundéIP.O.Box:812Yaounde´Cameroon Institute for Geological and Mining Research P.O.Box:4110NlongkakYaounde´Cameroon Department of Earth Sciences Faculty of ScienceUniversity of DoualaP.O.Box:24157DoualaCameroon Department of Geology Faculty of ScienceThe University of BueaP.O.Box:67BueaCameroon

The Proterozoic metasedimentary rocks of the Yaounde Group on the northern edge of the Congo Shield in Central Africa were investigated to understand their provenance and depositional ***,geochemistry,and field evidence helped to subdivide the metasediments into paragneiss,mica schist,chlorite schist,and quartzite which were derived from greywacke,shale,quartz arenite,litharenite *** are immature with some mature samples,moderately weathered and reworked Neo-and Post-Archean *** earth element signatures(Chondrite Eu/Eu^(*)≤1),enrichment of light rare earth elements over the heavy ones,and the La/Sc ratio(>0.7)are compatible with those of the intermediate and felsic sources from the upper continental *** metasediments were deposited in the continental arc setting and have evolved during Proterozoic times according to the Wilson cycle to form the West Gondwana including NE Brazil.

关键词： West Gondwana North Equatorial orogenic belt Yaounde Group Neoproterozoic basin Geochemistry of metasedimentary rocks Geodynamic evolution

Characterization of Alluvial Gold Bearing Sediments of Betare Oya District-East Cameroon, Implication for Gold Exploration and Recovery

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Open Journal of Geology 2017年第11期7卷 1724-1738页

作者： germain marie monespérance mboudou Kennedy Folepai Fozao Olivier Annoh Njoh Christopher Mbaringong Agyingi Economic Geology Unit Department of Geology University of Buea Buea Cameroon Sedimentology and Petroleum Geolgy/Engineering Unit Department of Geology University of Buea Buea Cameroon

Field studies (location Au pits, sampling of different layers of sedimentary sequences filling the pits, panning of sediments), litho-stratigraphic investigations, grain size analysis and outlining of depositional conditions revealed a characteristic fining upward sequence in all the sections of 08 Au-pits within the Betare Oya basin. A typical profile is 2.5 to 4.5 m thick and is composed of a 30 to 50 cm organic topsoil layer, underlain by a 1.5 m thick reddish brownish gold free saprolite, which is underlain by 1.5 m sandy section. From litho-stratigraphic investigations and grain size analysis results a quartz dominated gravelly 1.4 m thick layer consisting in boulders (275 mm), cobbles (2-−0.0148x2 + 1.2187x + 2.0344, R2 = 0.6929 (sandy layer);2) y = 0.0617x2 + 1.0849x + 0.8097, R2 = 0.8694 (gravelly layer);and y > R2 is satisfied in both cases. This implies that Au recovery from these layers could be effective through gravity separation using sieves mounted on classifiers of 7 cm (sandy layer) and 10 cm (gravelly layer) diameter.

关键词： Betare Oya Aspect Ratios Au Grains Yield Alluvial Sediments Pull-Apart Basin

Disaster Risk Resilience:Conceptual Evolution,Key Issues,and Opportunities

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International Journal of Disaster Risk Science 2022年第3期13卷 330-341页

作者： marie-Hélène Graveline Daniel germain Institut des Sciences de l’Environnement(ISE) Universitédu QuébecàMontréalMontréalH3C 3P8Canada Department of Geography Universitédu QuébecàMontréalMontréalH3C 3P8Canada

Resilience has become a cornerstone for risk management and disaster ***,it has evolved extensively both etymologically and conceptually in time and across scientific *** concept has been(re)shaped by the evolution of research and practice *** the opposite of vulnerability for a long time,resilience was first defined as the ability to resist,bounce back,cope with,and recover quickly from the impacts of *** avoid the possible return to conditions of vulnerability and exposure to hazards,the notions of post-disaster development,transformation,and adaptation(build back better)and anticipation,innovation,and proactivity(bounce forward)were then ***,resilience is characterized by a multitude of components and several *** present a selection of 25 components used to define resilience,and an interesting linkage emerges between these components and the dimensions of risk management(prevention,preparedness,response,and recovery),offering a perspective to strengthen resilience through the development of *** its potential,resilience is subject to challenges regarding its operationalization,effectiveness,measurement,credibility,equity,and even its ***,it offers applicability and opportunities for local communities as well as an interdisciplinary look at global challenges.

关键词： Community Disaster risk Resilience Sustainable development

Geochemical Characterization of Novokrivoyrog Metavolcanics: Tectonic Implications and Relationship with the Early Proterozoic Banded Iron Formation (BIF) of Krivoy Rog in Ukraine

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Open Journal of Geology 2012年第3期2卷 121-135页

作者： germain M. M. mboudou Cheo E. Suh George T. Mafany Economic Geology Unit Department of Geology and Environmental Science University of Buea Buea Cameroon Institute of Mining and Geological Research Regional Delegation of Scientific Research and Innovation South West Region Buea Cameroon

The geochemical characterization of Novokrivoyrog metavolcanics (2.2 Ga) and Krivoy Rog iron ores (1.8 Ga) in Ukraine represent an important tool for the understanding of their genesis and tectono-magmatic evolution. The petrological classification of the metavolcanics on SiO2/(Zr-TiO2) and (Zr-TiO2)/(Nb/Y) Harker-type diagrams shows similarities to subalkaline andesitic basalts. An additional classification of the basalts on TAS (Na2O + K2O/SiO2) and AFM (FeO-MgO-Na2O + K2O) diagrams exhibits a variable magmatic character from calc-alkaline to tholeiitic. The distribution of High Field Strength Elements, (HSFE: Ti, Zr, Y, Hf, Nb), V, Cr, and Rare Earth Elements (REE) in most of the rocks is close to calc-alkaline basalts (CAB) and can be compared to Precambrian mid-ocean ridge basalts (MORB) where high thermal (>250°C) basaltic alteration is intensive under pH conditions between 2 and 4. These contributed to the deposition of the Krivoy Rog BIFs. Indeed REE distribution patterns of the BIFs suggest that they can be subdivided into shales and shaly BIFs (rich in LREEs since their detrital and clastic inputs are much higher) with (La/Yb)N > 1 as indication of clastic inputs;chert and cherty BIFs showing positive Eu anomaly with (La/Yb)N 1 emphasizes post-depositional effects related to the enrichment of light REEs over heavy REEs with a positive Eu anomaly. The distribution of REE patterns of Krivoy Rog BIFs can finally be compared to Precambrian iron formations of mixed submarine hydrothermal fluids and seawater origin which correspond to the MORB signature of the Novokrivoyrog metavolcanics.

关键词： BIF Geochemistry Ukraine REE Metavolcanics

Diagnostic and Therapeutic Options of Breast Cancer Patients in Yaounde, Cameroon

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Advances in Breast Cancer Research 2022年第1期11卷 50-62页

作者： Jean Dupont Kemfang Ngowa Hortense Jeanne Fouedjio Annaïk Morelle Tchami Julienne Louise Ngo Likeng Christelle Domngang Noche Brigitte Wandji Djouonang Florent Fouelifack Ymele Pascal Foumane Emile Telesphore mboudou Pierre marie Tebeu Faculty of Medicine and Biomedical Sciences University of Yaounde I Yaounde Cameroon University of Montagnes Bangangté Cameroon Catholic University of Central Africa Yaounde Cameroon Higher Institute of Medical Technology Nkolondom Cameroon

Introduction: Breast cancer remains a public health problem due to its severity and because it is the leading cause of death from cancers in women worldwide as well as in Cameroon. Our objective was to study the diagnostic and therapeutic options that patients followed for breast cancer choose in Yaounde. Method: This was an analytical cross-sectional study with prospective data collection among patients followed for breast cancer at two referral hospitals in Yaounde from February 1, 2019 to August 31, 2019. Data collected were recorded and analyzed using R application version 3.5.0., p va

关键词： Breast Cancer Traditional Medicine Therapeutic Abstention Naturopathy Contemporary Medicine

Carbonate Enrichment in Volcanic Debris and Its Relationship with Carbonate Dissolution Signatures of Springs in the Sabga-Bamessing, North West, Cameroon

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International Journal of Geosciences 2014年第1期5卷 107-121页

作者： Raymond Beri Verla germain M. M. mboudou Olivier Njoh Gilles Nyuyki Ngoran Aloysius Ngambu Afahnwie 1Department of Geology Faculty of science University of Buea Buea Cameroon 2Explorers 33 Consultants Yaounde Cameroon 1Explorers 33 Consultants Yaounde Cameroon 2Ministry of Mines Yaounde Cameroon Department of Geology Faculty of science University of Buea Buea Cameroon

Sabga-Bamessing is a part of the Bamenda Mountains, an extinct volcanic center of the West Cameroon Highlands along the Cameroon Volcanic Line (CVL). The pristine volcanic rocks of the Sabga area are alkali mafic to felsic (basanites, phonolites, trachytes and rhyolites). Some weathered sections of a heterolithologic debris flow with a suppositious primary chemistry of the original volcanic rocks prior to weathering have shown significant calcium carbonate enrichment. CaO and LOI values of up 61.31% and 41.72% respectively show corresponding enrichment of 16.54 and 10.88, when compared with average fresh volcanic rocks. Na+ normalized molar ratios computed from the chemistry of springs and rivers show carbonate dissolution signature which is contrary to silicate dissolution expected in acid volcanic rocks. Saturation indices (SI) calculated with PHREEQC reveal that brackish to saline springs are supersaturated with Calcite (CaCO3), Aragonite (CaCO3), Dolomite (CaMg(CO3)2 and Hydroxyl apatite (Ca5(PO4)3OH). Recharging contributions to spring water chemistry deviate from those produced by rock weathering, precipitation and evaporation/crystallization. An enrichment process is therefore predicted as a recharging contributor to water chemistry.

关键词： Cameroon Volcanic Line (CVL) Carbonate Enrichment Carbonate Dissolution Weathering

Sedimentology and Geochemical Evaluation of Lignite-Argillite Sequences in a Named Basin in Bali Nyonga, Northwest, Cameroon

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International Journal of Geosciences 2015年第8期6卷 917-937页

作者： Roger Ngong Ngia Christopher M. Agyingi Josepha Foba-Tado germain M. M. mboudou Anita Nshukwi Victorine N. Beckley Department of Geology University of Buea Buea Cameroon Department of Chemistry University of Buea Buea Cameroon

The sedimentology and geochemistry (major and trace element compositions) of lignite and argillite (carbonaceous shale and claystone) sequences in a Basin in Bali Nyonga, west of the Bamenda Mountain have been investigated to determine their sequences and the prevailing environmental?conditions which control their formation. Ten representative samples were obtained fromtrenches, pits, and river and stream valleys in the study area. These samples and their ashes were subsequently examined using X-ray fluorescence spectrometry (XRF), inductively coupled plasma spectrometry (ICP), and X-ray diffraction analysis (XRD). The geochemical results revealed that thelithophile, chalcophile and siderophile elements were dominantly epigenetic in origin, mainly?from detrital sources supported by high silica and alumina concentrations in all the samples. The mineral phases identified were quartz, kaolinite, illite, pyrite, hematite, and minor phases of feldspars,pseudorutile. The relatively high silica (54.10 wt%) and alumina contents (27.77 wt%) in these?samples can be explained by high detrital input during peat formation. The low contents of MgO and CaO in the analysed samples agree very much with the continental setting of the peat formating basin. A clayey microband derived from alkaline volcanic ashes was identified in the lignite and the dominant composition of these clayey microbands was mixed-layer clay minerals of illite and kaolinte, which were interlayered with organic bands. The modes of occurrence of ash bands indicated that the volcanic activities were characterized by multiple eruptions, short time interval?and small scale for each eruption during peat accumulation. The ratios of redox-sensitive traceelement (V/Cr versus Ni/Co and V/V + Ni versus Ni/Co), Sr/Ba, and major oxides ratio (CaO + MgO + Fe2O3)/(SiO2?+ Al2O3) from the analysed samples from Bali Nyonga indicate a terrestrial, reductive (oxic), littoral to brackish water environmental conditions which are ch

关键词： Lignite Bali Nyonga Argillite Clay Minerals Cameroon Volcanic Line (CVL) Lacustrine Basin

Spatial Availability of Nitrogen and Pesticides in the Surface Layers of Agricultural Soils of Tropical Hydrosystems in the Wet Season: Case of the BéréWatershed in Côte d’Ivoire (West Africa)

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Journal of Agricultural Chemistry and Environment 2021年第2期10卷 143-168页

作者： Mian germain Eba Kouakou Sylvain Akpo Pétémanangnan Jean-marie Ouattara Tiangoua Koné Lacina Coulibaly Environment and Aquatic Biology Laboratory Nangui Abrogoua University Abidjan C&ocirc te d’Ivoire Central Environment Laboratory Ivorian Antipollution Center Abidjan C&ocirc te d’Ivoire Department of Chemistry University of Man Man C&ocirc te d’Ivoire

The objective of this study was to assess the contribution of the spatial organization of cropping systems and the physicochemical properties of surface layers of the agricultural zones soils in tropical hydrosystems to the spatial availability of nitrogen and pesticides during the wet season, such as the Béré watershed (BW) in C?te d’Ivoire. For this purpose, after mapping the spatial distribution of the BW cropping systems based on the likelihood classification methodology of satellite images of the study area, 27 samples from the 0 - 20 cm horizon of the soil surface layers of the agricultural areas were taken during the wet and agricultural season of the year 2016. The Kjeldahl method has been used to evaluate the total nitrogen concentration and high-performance liquid chromatography (HPLC) chain made it possible for the analysis of pesticide residues in the soil solutions. Geostatistical analysis and processing of spatial data and physicochemical and agrochemical soil parameters revealed that two major agricultural areas stand out in the BW, namely the Béré upstream watershed (BUW) dominated at 32.65% by annual croppings (maize, cotton, rainfed or lowland rice, market gardening, etc.) and the Béré downstream watershed (BDW) by large areas of perennial croppings (cashew nuts, cocoa, etc.), i.e. 21.47%. Agricultural soils in BW are usually of the moderately desaturated ferralitic type with a low acid pH and a quite strong temperature, such as those of tropical soils’ characteristics. However, agricultural soils in the BUW are characterized by higher proportions of sand and coarse sand. The parameters such as total porosity, cation exchange capacity, clay, organic matter, silt, fine silt, coarse silt, and potassium ions, are higher in the soils of the agricultural area of the BDW. Moreover, soils in the agricultural areas of the BUW are less rich in total nitrogen (0.84 g·k

关键词： Agrochimical Products Soils Contamination Water Resources Pollution West Africa Tropical Hydrosystems Béré Watershed Côte d’Ivoire

Onchocerca volvulus as a risk factor for developing epilepsy in onchocerciasis endemic regions in the Democratic Republic of Congo:a case control study

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Infectious Diseases of Poverty 2018年第1期7卷 781-786页

作者： Michel Mandro Patrick Suykerbuyk Floribert Tepage Degratias Rossy Francoise Ngave Mirza Nazmul Hasan An Hotterbeekx germain Mambandu Jean marie Kashama Anne Laudisoit Robert Colebunders Provincial Health Division of Ituri Ministry of HealthBuniaDemocratic Republic of Congo Global Health Institute University of AntwerpAntwerpBelgium Ministry of Health ButaDemocratic Republic of Congo Programme national de lutte contre l’onchocercose KisanganiDemocratic Republic of Congo Centre de Recherche en Maladies Tropicales de l’Ituri RethyDemocratic Republic of Congo University of Hasselt Campus DiepenbeekHasseltBelgium Office of the governor of Tshopo KisanganiDemocratic Republic of Congo Neuropsychopathologic Centre of Mont Amba(CNPP) University of KinshasaKinshasaDemocratic Republic of Congo EcoHealth Alliance New YorkUSA

Background:A high prevalence of epilepsy has been observed in onchocerciasis endemic areas in the Democratic Republic of Congo(DRC).With this study we aimed to investigate whether Onchocerca volvulus infection is a risk factor for developing epilepsy in onchocerciasis endemic regions in the ***:Between October and December 2015,a multi-centre case control study was performed in onchocerciasis endemic health zones(HZ)in the DRC:one study site was situated in Tshopo Province in the HZ of Wanierukula(village of Salambongo)where there had been 13 annual community distributions of treatment with ivermectin(CDTI),a second was situated in Ituri Province in the HZ of Logo(village of Draju)where ivermectin had never been distributed and in the HZ of Rethy(village of Rassia)where there had been THREE CDTI annual campaigns before the *** with unprovoked convulsive epilepsy of unknown etiology were enrolled as cases(n=175).Randomly selected healthy members of families without epilepsy cases from the same village and age-groups and were recruited as controls(n=170).Results:Onchocerciasis associated symptoms(e.g.,itching and abnormal skin)were more often present in cases compared to controls(respectively,OR=2.63,95%CI:1.63-4.23,P<0.0001 and OR=3.23,95%CI:1.48-7.09,P=0.0034).A higher number of cases was found to present with microfilariae in skin snips and with *** IgG4 antibodies in the blood compared to ***,the microfilariae load in skin snips was 3-10 times higher in cases than ***:This case control study confirms that *** is a risk factor for developing epilepsy in onchocerciasis endemic regions in the DRC.

关键词： Onchocerciasis Epilepsy Case control study Risk factors Democratic Republic of Congo

A Phelipanche ramosa KAI2 protein perceives strigolactones and isothiocyanates enzymatically

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Plant Communications 2021年第5期2卷 132-147页

作者： Alexandre de Saint germain Anse Jacobs Guillaume Brun Jean-Bernard Pouvreau Lukas Braem David Cornu Guillaume Clavé Emmanuelle Baudu Vincent Steinmetz Vincent Servajean Susann Wicke Kris Gevaert Philippe Simier Sofie Goormachtig Philippe Delavault François-Didier Boyer Institut Jean-Pierre Bourgin INRAEAgroParisTechUniversitéParis-Saclay78000 VersaillesFrance Department of Plant Biotechnology and Bioinformatics Ghent University9052 GentBelgium Center for Plant Systems Biology VIB9052 GentBelgium Department of Biomolecular Medicine Ghent University9000 GhentBelgium Center for Medical Biotechnology VIB9000 GhentBelgium Laboratoire de Biologie et Pathologie Végétales(LBPV) Equipe d’Accueil 1157Universitéde Nantes44000 NantesFrance Institute for Biology Humboldt-Universit€at zu Berlin10115 BerlinGermany UniversitéParis-Saclay CEACNRSInstitute for Integrative Biology of the Cell(I2BC)91198Gif-sur-YvetteFrance UniversitéParis-Saclay CNRSInstitut de Chimie des Substances NaturellesUPR 230191198Gif-sur-YvetteFrance

Phelipanche ramosa is an obligate root-parasitic weed that threatens major crops in central *** order to germinate,it must perceive various structurally divergent host-exuded signals,including isothiocyanates(ITCs)and strigolactones(SLs).However,the receptors involved are still ***,we identify five putative SL receptors in *** and show that PrKAI2d3 is involved in the stimulation of seed *** demonstrate the high plasticity of PrKAI2d3,which allows it to interact with different chemicals,including *** SL perception mechanism of PrKAI2d3 is similar to that of endogenous SLs in non-parasitic *** provide evidence that PrKAI2d3 enzymatic activity confers hypersensitivity to ***,we demonstrate that methylbutenolide-OH binds PrKAI2d3 and stimulates *** germination with bioactivity comparable to that of *** study demonstrates that *** has extended its signal perception system during evolution,a fact that should be considered for the development of specific and efficient biocontrol methods.

关键词： a/b-hydrolase receptor seed germination stimulant strigolactones isothiocyanates Phelipanche ramosa