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Geochemical evaluation of mineralization potential of the Somie-Ntem area within the Tikar plain,Cameroon:implication on petrogenesis

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Acta Geochimica 2022年第5期41卷 861-886页

作者： Mero Yannah Yaya Fodoue Maurice Kwekam benoit joseph mbassa Juliana Amboh Tifang Armand Dongmo Kagou Samuel Ndonwi Ayonghe Institute of Geological and Mining Research YaoundeCameroon Department of Earth Sciences University of DschangDschangCameroon Central Unit for Internal Control and Evaluation University of BueaBueaCameroon

Somie-Ntem area of the Tikar plain belongs to the western Cameroon *** lithology of the plain has been characterized,and the mineral potential is still unclear despite previous reports on Sn deposit within one of the magmatic *** results show two groups of granitic rocks displaying oxidized and reduced character;(1)mesocratic(oxidized)granites including biotitebearing,hornblende-biotite-bearing,hornblende-epidotebearing and pyroxene-bearing;(2)leucogranites(reduced)that are generally amphibole-pyroxene *** granitoids are hosted by gneisses and metasedimentary rocks partially covered by *** element composition shows high-K calc-alkaline to shoshonite affinity,metaluminous to weakly peraluminous I-type *** granites show moderately negative Eu anomaly,depleted in Nb,P,Ti,and are related to syn-collisional *** are post-orogenic with strong negative Eu anomaly,depleted in Ba and Sr and enriched in Hf,Nb and *** are fertile in Sn and Zn,enriched through postmagmatic metasomatism and ***–Cu–Ni–V mineralization occurs in hornblende-bearing gneisses and their enrichment suggests a possible Ni–Cutype PGEs mineralization in this ***,their trace element shows high Ni/Cu,very low Rb/Sr,low LILE and LREE which indicates mantle fractionation at *** absence of olivine and pyroxene,and increased SiO_(2)and Al_(2)O_(3)in the Cr–Cu–Ni–V-bearing rocks show that the parent magma experienced fractional crystallization and crustal contamination during ***,the high Zr/Rb and K/Rb ratios show that hydrothermal activity was not intense to enhance mineralization in the *** in the direction of stress during shear deformation inhibited an effective hydrothermal activity and ore deposition in the region.

关键词： Geochemistry Mineralization Somie-Ntem Tikar plain Cameroon

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Matrix Assisted Laser Desorption Ionization Time of Flight(MALDI-TOF)-Mass Spectrometry and^(13)C-NMR-Identified New Compounds in Paraberlinia bifoliolata(Ekop-Beli)Bark Tannins

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Journal of Renewable Materials 2024年第3期12卷 553-568页

作者： Liliane Nga benoit Ndiwe Achille Bernard Biwolé Antonio Pizzi Jean Jalin Eyinga Biwole joseph Zobo Mfomo Laboratory of Forest Resources and Wood Valorization Training Unit in Engineering SciencesPost Graduate School of Fundamental and Applied SciencesUniversity of DoualaP.O.Box 1872DoualaCameroun Laboratory of Mechanics Training Unit in Engineering SciencesPost Graduate School of Fundamental and Applied SciencesUniversity of DoualaP.O.Box 2701DoualaCameroun Laboratory of Studies and Research on Wood Material(LERMAB) University of LorraineNancyFrance

Extracts of plant origin,particularly tannins,are attracting growing interest for the sustainable development of materials in the industrial *** discovery of new tannins is therefore *** aim of this work was to contribute to the understanding of the properties of Paraberlinia bifoliolata tannin by Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectroscopy MALDI-TOF/MS and Carbon 13 Nuclear Magnetic Resonance(13C NMR).The chemical composition of tannin extracted from Paraberlinia bifoliolata bark was determined,as was the mechanical strength of the resin hardened with Acacia nilotica *** by successive water extraction was 35%.MALDI-TOF/MS analysis revealed the presence of three new compounds in this tannin,previously unknown in this family of *** are 3-hydroxyproline acid,N-methyl-4-hydroxypipecolic acid and N-methyl-5-dihydroxypipecolic *** identification of the above molecules means that this tannin can be used for industrial applications,as a resin in the manufacture of particleboard and in the formulation of green corrosion *** information is reinforced by 13C NMR spectrometry,which indicates the presence of several polyflavonoid units,confirming the condensed nature of the *** analysis of the resin formed by the purified tannin of Paraberlinia bifoliolata to which a vegetal biohardener has been added provided a Modulus of Elasticity(MOE)value of 4840 MPa at 150℃,confirming its possible use as a binder resin in the manufacture of wood panels as well as for the formulation of a corrosion inhibitor.

关键词： Tannin Paraberlinia bifoliolata Central African wood species MALDI-TOF/MS 13C NMR bark extracts thermomechanical behaviour wood-binder

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Reactions of Maruca Resistant Transgenic Cowpea to Cowpea Aphid-Borne Mosaic Virus

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Agricultural Sciences 2024年第7期15卷 742-753页

作者： Mounyratou Rabo Moustapha Ouédraogo Orokia Coulibaly Assita Traoré-Barro Salimata Traoré Teyioue benoit joseph Batieno Chantal Kaboré-Zoungrana Aboubacar Toguyeni Oumar Traoré Laboratoire National de Bioscurit Agence Nationale de Bioscurit (ANB) Ouagadougou Burkina Faso Institut de lEnvironnement et Recherches Agricoles Dpartement Productions Vgtales Ouagadougou Burkina Faso Laboratoire dEtudes et de Recherches sur les Ressources Naturelles et les Sciences de lEnvironnement (LERNSE) Universit Nazi BONI Bobo-Dioulasso Burkina Faso Laboratoire De Gntique et Amlioration Des Plantes (LAGAMEP) Institut de lEnvironnement et Recherches Agricoles Ouagadougou Burkina Faso Laboratoire De Protection et Dfense Des Cultures (LAPRODEC) Institut de lEnvironnement et Recherches Agricoles Ouagadougou Burkina Faso

Cowpea (Vigna unguiculata L. [Walp.]) in one of the main grain legumes contributing to food security and poverty alleviation in Sub-Saharan Africa. To control the highly damaging legume pod borer Maruca vitrata F., transgenic cowpea lines expressing the insecticidal Cry1Ab Bt protein were developed. In this study, we evaluated the impact of Cry1Ab transgene expression on the susceptibility of four cowpea lines (named IT97K-T, IT98K-T, Gourgou-T and Nafi-T) and their respective non-transgenic near isogenic lines (IT97K, IT98K, Gourgou and Nafi) to Cowpea aphid-borne mosaic virus (CABMV) in greenhouse conditions. In a preliminary quality control test by enzyme-linked immunosorbent assay, the presence of Cry1Ab protein in transgenic seed lots ranged from 59% to 72%, with no significant differences among the lines (χ2 = 3.26;p = 0.35). Upon virus inoculation, all cowpea lines exhibited mosaic symptoms with similar severity between 7- and 11-day post-inoculation. No significant differences were observed in symptom severity. Significant differences were found between cowpea lines for time of symptom onset, virus accumulation in plants and days to 50% flowering. However, while comparing pairs of transgenic lines and corresponding non-transgenic lines, virus accumulation showed not significant differences whatever the pair. Time of symptom onset and days to 50% flowering did not also differ significantly between pairs of cowpea lines except Nafi/Nafi-T in which transgenic Nafi-T showed earlier symptoms (7.4 ± 0.7 vs. 8.9 ± 0.8 days post-inoculation) and shorter flowering time (37.3 ± 0.6 vs. 42 ± 1.7 days after sowing). Overall, these findings improve our understanding of the effects of Cry1Ab gene mediated genetic modification on cowpea infection by Cowpea aphid-borne mosaic virus, with potential implications for environmental safety assessment.

关键词： Cowpea Cry1Ab Cowpea Aphid-Borne Mosaic Virus Environmental Safety

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Supervised Learning Method: Critical Analysis and Updating of Cubing Rate Formulas for Determining Bark Masses of Prunus africana (Hook. f.) Kalkman (Rosaceae) in Cameroon

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Open Journal of Forestry 2024年第3期14卷 346-368页

作者： Armand Ndedy Bile Alain Mpouam benoit Fouadjio Lorette Guedeu Kambale Muhesi Steve Tassiamba Paulette Kouam Eric Wete Marius Ela Michèle Yimga joseph Ambara Louis Aimé Fono Jean Lagarde Betti Department of Plant Biology Faculty of Science The University of Douala Douala Cameroon Department of Wood and Forest Sciences ISABEE University of Bertoua Bertoua Cameroon Department of Water and Forests Higher Institute of Agronomic Veterinary and Forestry Studies of Butembo Butembo Democratic Republic of Congo Department of Forestry Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Cameroon Department of Biology and Plant Faculty of Sciences University of Maroua Maroua Cameroon Deutsche Gresellschaft fur Internationale Zusammenarbeit GmbH (GIZ) Bertoua Cameroon Department of Mathematics and Computer Science Faculty of Science The University of Douala Douala Cameroon

The stem barks of Prunus africana are used in the treatment of the benign prostate. Cameroon is one of the important exporters of the barks. Despite the important measures adopted in Cameroon for sustaining its harvesting, some many chalenges still remain. The objective of this work is to refine the forest management parameters in relation to P. africana in the regions of Adamaoua and the South-West by developing a volume rate which makes it possible to estimate the production for a new stem. The work took place in two phases: in the South-West in 2010 and in Adamaoua in 2011. Data collection used the semi-direct method, while the cubing equation was deduced by the multiple linear regression method. Two models for volume estimation and three models for mass prediction were developed. The predictive parameters retained are diameter, height of the bole and thickness of the bark. Results show that the average mass of the dry bark for a given P. africana tree species is 27.55 ± 14.44 kg and this varies according to the site. The strong adjusted coefficient of determination (adjusted R2) observed illustrates the reliability of the proposed models. These models provide a reliable tool that can be adopted as a standard in Cameroon for P. africana.

关键词： Prunus africana Prostate Quota Mass Model Sustainable Management

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Reactions of Maruca Resistant Transgenic Cowpea to Cowpea Aphid -Borne Mosaic Virus

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Agricultural Sciences（农业科学） 2024年第7期 742页

作者： Mounyratou Rabo Moustapha Ouédraogo Orokia Coulibaly Assita Traoré-Barro Salimata Traoré Teyioue benoit joseph Batieno Chantal Kaboré-Zoungrana Aboubacar Toguyeni Oumar Traoré

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Multidrug-Resistant of Escherichia coli and Salmonella spp. Strains in Chicken Feces Intended for Consumption in Open Spaces of Ouagadougou, Burkina Faso

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Open Journal of Applied Sciences 2024年第4期14卷 881-892页

作者： Stéphanie Lynseh Carine Sita Bénao Dabiré Amana Métuor Abdoul Karim Ouattara Rahimatou Yasmine Wendkouni Tiemtoré Nicolas Ouédraogo Blandine Ouédraogo Rhaina Olivia Badini Lionel Eliada benoit Bambara Serge Sougué Jacques Simporé Biomolecular and Genetic Laboratory (LABIOGENE) Pietro Annigoni Biomolecular Research Center (CERBA) Department of Biochemistry-Microbiology University Joseph Ki-Zerbo Ouagadougou Burkina Faso Department of Biochemistry-Microbiology University of D&#233dougou D&#233dougou Burkina Faso National Malaria Research and Training Centre (CNRFP) Ouagadougou Burkina Faso

Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.

关键词： Multidrug-Resistant Chicken Ouagadougou Escherichia coli Salmonella spp. Antibiotic

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Mitochondrial dysfunction activates the AMPK signaling and autophagy to promote cell survival

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Genes & Diseases 2016年第1期3卷 82-87页

作者： Baozhong Zhao Lei Qiang Joy joseph Balaraman Kalyanaraman benoit Viollet Yu-Ying He Department of Medicine Section of DermatologyUniversity of ChicagoChicagoILUSA Free Radical Research Center Medical College of WisconsinMilwaukeeWIUSA INSERM U567 CNRS UMR8104Department of EndocrinologyMetabolism and CancerInstitut CochinUniversite´Paris 575014 ParisFrance

Autophagy is a cellular self-eating process essential for stress response and maintainingtissue homeostasis by lysosomal degradation of unwanted or damaged proteins and ***, we show that cells with defective mitochondria induce autophagy to promotecell survival through activating the AMPK pathway. Loss of mitochondrial complex III proteincytochrome b activates the AMPK signaling and induced autophagy. Inhibiting mitochondria energeticsby mitochondria-targeted agents activates the AMPK signaling and induced *** inhibition of AMPK inhibits autophagy induction in cells with defective mitochondria,while genetic inhibition of autophagy has no effect on AMPK activation. Mitochondria dysfunctionhas no effect of DNA repair of UV-induced DNA damage. However, mitochondria dysfunctionsensitizes cells to apoptosis induced by UV radiation. Genetic inhibition of autophagy orAMPK sensitized cells to apoptosis in cells with defective mitochondria. Our results demonstratethat AMPK and autophagy senses mitochondria dysfunction and serves as a mechanismfor survival. Our findings may provide new insights into the interplay between mitochondriafunction and autophagy process in maintaining tissue homeostasis, and suggest that this interactionmay play important roles in diseases such as cancer and neurodegeneration.

关键词： AMPK Apoptosis Autophagy DNA repair Mitochondria Ultraviolet radiation UV

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Supervised Learning Method: Critical Analysis and Updating of Cubing Rate Formulas for Determining Bark Masses of Prunus africana (Hook. f.) Kalkman (Rosaceae) in Cameroon

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Open Journal of Forestry（林学期刊） 2024年第3期 346页

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The beginnings of plasmomechanics： towards plasmonic strain sensors

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Frontiers of Materials Science 2015年第2期9卷 170-177页

作者： Thomas MAURER joseph MARAE-DJOUDA Ugo CATALDI Arthur GONTIER Guillaume MONTAY Yazid MADI benoit PANICAUD Demetrio MACIAS Pierre-Michel ADAM Gaetan LEVEQUE Thomas BURGI Roberto CAPUTO Laboratory of Nanotechnology and Instrumentation in Optics (LNIO) ICD CNRS UMR 6281 University of Technology of Troyes CS 42060 10004 Troyes France The Laboratory of Mechanical Systems and Concurrent Engineeringl ICD CNRS UMR 6281 University of Technology of Troyes CS 42060 10004 Troyes France Ermess EPF Sceaux France Center of Materials Mines ParisTech UMR CNRS 7633 BP 87 91003 Evry Cedex France Institute of Electronics Microelectronics and Nanotechnology (IEMN CNRS-8520) Cite Scientifique Avenue Poincare 59652 Villeneuve d'Ascq France Department of Physical Chemistry University of Geneva 30 Quai Ernest-Ansermet 1211 Geneva 4 Switzerland Department of Physics and CNR-NANOTEC University of Calabria 87036 Rende Italy

This article exposes the beginnings of a new field which could be named as ＂plasmomechanics＂. Plasmomechanics comes from the convergence between mechanics and plasmonics. Here we discuss a relatively recent topic whose technolo- gical aim is the development of plasmonic strain sensors, The idea is based on the ability to deduce Au nanoparticles （NPs） distance distributions from polarized optical extinction spectroscopy which could thus give access to material strains. Variations of interparticle distances distributions can indeed lead to variations of plasmonic coupling and thus to material color change as shown here experimentally and numerically for random Au NP assemblies deposited onto elastomer films,

关键词： localized surface plasmon resonance (LSPR) metallic nanoparticle strain composite material elastomeric film

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Influence of initial microstructure and grain size on transformation of bainite to austenite in large size forgings

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Journal of Iron and Steel Research International 2018年第5期25卷 554-562页

作者： Emna Ben Fredj Hadi Ghasemi Nanesa Mohammad Jahazi Jean-benoit Morin Department of Mechanical Engineering Ecole deTechnologie Superieure Montreal QC H3C 1K3 Canada Finkl Steel-Sorel St-Joseph-de-Sorel QC J3R 3M8 Canada

The kinetics of austenite formation in the surface and center regions of a 40 t forged ingot of a high-strength medium- carbon low-alloy steel was studied using high-resolution dilatometry. The starting microstructures from the surface or center regions had different proportions of bainite and residual austenite as well as different prior austenite grain sizes. Two heating rates representing the actual heating rates in the surface （5℃ s -1） and center regions （0.5℃ s -1） of large size forged blocks were utilized. Dilatometric curves revealed only one transformation step of austenite formation at both heating rates independent of grain size or proportion of phases. Optical microscopy, field emission gun scanning electron microscopy and X-ray diffraction were used to study microstructure evolution and confirm the results obtained by dilatometry. The kinetic parameters for austenite formation were determined from the dilatometry data by Johnson-Mehl- Avrami-Kolmogorov （JMAK） equation. The JMAK coefficients were determined for each condition of the investigated steels. The calculations indicated that the nucleation and growth of austenite in the surface region were accelerated more than 10,000 times due to a significantly smaller average prior austenite grain size, stability of initial retained austenite, and accumulation of coarse carbides at the surface. The results were discussed in the framework of classical nucleation and growth theories using the kinetic parameters for austenite formation.

关键词： Large size ingot Medium-carbon low-alloy steel Initial microstructure Grain size Austenite formation

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