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Analysis of Spatio-Temporal Dynamics of Land Use in the Bouba Ndjidda National Park and Its Adjacent Zone (North Cameroun)

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Open Journal of Forestry 2020年第1期10卷 39-57页

作者： José Elvire Boukeng Djiongo André Desrochers Marie Louise Tiencheu Avana Damase Khasa Louis Zapfack éric fotsing Department of Wood and Forest Sciences Faculty of Forestry Geography and Geomatics Laval University Quebec Canada Garoua Wildlife School Garoua Cameroun Department of Forestry Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang Cameroon Department of Plant Biology Faculty of Sciences University of Yaoundé 1 Yaoundé Cameroon Department of Computer Engineering University Institute of Technology Fotso Victor University of Dschang Bandjoun Cameroon

We evaluated the dynamics of land use in the Bouba Ndjidda National Park (BNNP) and adjacent areas, in northern Cameroon. Using a maximum likelihood supervised classification of satellite images from 1990 to 2016, coupled with field and a socio-economic survey, we performed a robust land-use classification. Between 1990 and 2016, the area included eight classes of land use, with the largest in 1990 being the woody savannah (42.9%) followed by the gallery forest (20.2%) and the clear forest (16.3%). Between 1990 and 1999, the gallery forest lost 64.8% of its area mostly to the benefit of woody savannahs. Between 1999 and 2016, the largest loss of area was that of the clear forest, which decreased generally by 43.2% in favor of woody savannah. Rates of increase of crop field areas were 59.6% and 78.8% respectively for the periods of 1990 to 1999 and 1999 to 2016 to the detriment of woody savannahs. We attribute the changes in land use observed mainly to the increasing human population and associated agriculture, overgrazing, fuelwood harvesting and bush fires. The exploitation of non-timber forest products and climatic factors may also have changed the vegetation cover. We recommend the implementation of farming techniques with low impact on the environment such as agroforestry.

关键词： Remote Sensing Spatio-Temporal Dynamics Bouba Ndjidda National Park Vegetation Cover Land Use

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Design of an Interconnection Architecture and Sizing of Two (2) EPC Core Networks: The Case of Orange-Guinea

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Journal of Energy and Power Engineering 2024年第2期18卷 59-70页

作者： Mamadou Sadigou Diallo Kadiatou Aissatou Barry Amadou Lamarana Bah Mamadou Sanoussy Camara Janvier fotsing Amadou Barry Amadou Oury Bah Gamal Abdel Nasser University of Conakry(UGANC) P.O.BOX 1147Conakry 001BP 1147Republic of Guinea National Advanced School of Engineering University of Yaoundé1Yaoundé1001BP 337Republic of Cameroon

With the arrival of the 4G and 5G,the telecommunications networks have experienced a large expansion of these *** enabled the integration of many services and adequate flow,thus enabling the operators to respond to the growing demand of *** rapid evolution has given the operators to adapt,their methods to the new technologies that *** complexity becomes more important,when these networks include several technologies to access different from the heterogeneous network like in the 4G *** dimensional new challenges tell the application and the considerable increase in demand for services and the compatibility with existing networks,the management of mobility intercellular of users and it offers a better quality of ***,the proposed solution to meet these new requirements is the sizing of the EPC(Evolved Packet Core)core network to support the 5G access *** the case of Orange Guinea,this involves setting up an architecture for interconnecting the core networks of Sonfonia and *** objectives of our work are of two orders:(1)to propose these solutions and recommendations for the heart network EPC sizing and the deployment to be adopted;(2)supply and architectural interconnection in the heart network EPC and an existing heart *** our work,the model of traffic in communication that we use to calculate the traffic generated with each technology has link in the network of the heart.

关键词： 5G network 4G network(EPS(evolved packet system)) 3G network(UMTS:Universal Mobile Telecommunications System) EPC network of the heart architecture dimensional Orange Guinea technology service

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Stimulatory Effect of Tithonya diversifolia-by Products on Plantain Banana Vivoplants in Nursery (A Review)

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American Journal of Plant Sciences 2024年第9期15卷 726-745页

作者： Cécile Annie Ewané Arouna Meshuneke Gaston Elock Mbang Fabrice Damien Wassom William Asah Che Glen Takang Beyang Craftsman Ndula Ndula-Nan Landry fotsing Silatsa Jospin Walter Kom Timma Marie-Paule Kengoum Djam Rosine Arckange Barakielle Bindzi Abah Nicolas Niemenak Department of Biochemistry Faculty of Science University of Yaounde 1 Yaounde Cameroon Laboratory of Biochemistry and Vegetal Physiology of Higher Teachers Training College University of Yaounde 1 Yaounde Cameroon Laboratory of Phytoprotection and Valorisation of Genetic Resources of The Biotechnology Centre University of Yaounde 1 Yaounde Cameroon Department of Biological Science Higher Teachers Training College University of Yaounde 1 Yaounde Cameroon

Plantain banana is an important cash crop that serves as stable food for millions of people around the world and contributes to income generation. Indeed, they provide a major staple food crop for millions of people and play an important role in the social fabric of many rural communities. Plantain banana cultivation encounters major problem of seedlings unavailability that are essential for the creation of new plantations, as well as parasitic constraints. Mycosphaerella fijiensis is the main pathogen attack constraints of banana plant responsible of black Sigatoka disease, and viruses, which can severely reduce the photosynthetic leaf area, leading to banana production losses of more than 80% in plantations with soil fertility problems. The repeated use of synthetic input is the origin of contamination to the environment, different pollution sources of plants and human health, as well as resistance to some strains of pathogens and plant fertilization problems over time. Recent works carried out in nursery have shown that vivoplants of plantains treated with biostimulants based on natural products notably Tithonia diversifolia biopromote good growth and less susceptibility to M. fijiensis. Indeed, an increase in agromorphological characteristics, good accumulation of growth and defense biomarkers was also observed. In this context, Tithonia diversifolia is shown to be involved in the stimulatory effect mechanism of growth promotion and defensive reaction of plantain vivoplants against various pathogens and it is suggested to be acting as a vital stimulator. This article reviews the current state of knowledge on plantain banana cultivation constraints and on the potential of Tithonia diversifolia in relation with its different stimulatory effects on plantain vivoplants.

关键词： Tithonia diversifolia Plantain Banana Black Sigatoka Disease Growth Biopromotion Bioprotection Induced Resistance Biofungicidal Effect

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Effect of Biostimulants Based on Natural Products on the Growth and Nutritional Value of Bean (Phaseolus vulgaris L.)

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American Journal of Plant Sciences 2024年第7期15卷 492-518页

作者： Aimé Giresse Tzeuton Flore Eliane Eyenga Arouna Meshuneke Gaston Mbang Elock Fabrice Damien Wassom Walter Jospin Timma Kom Marie Paule Djam Kengoum Erica Cabrelle Damtse Damtse Landry Silatsa fotsing William Asah Che Marlyne Josephine Mananga Nicolas Niemenak Cécile Annie Ewané Laboratory of Plant Physiology and Biochemistry Higher Teachers Training College University of Yaound 1 Yaound Cameroon Department of Biochemistry Faculty of Sciences University of Yaound 1 Yaound Cameroon Laboratory of Food Sciences and Metabolism University of Yaoundé 1 Yaoundé Cameroon Laboratory of Phytoprotection and Valorisation of Genetic Resources of the Biotechnology Centre University of Yaound 1 Yaound Cameroon Department of Biological Sciences Higher Teachers Training College University of Yaound 1 Yaound Cameroon

Beans (Phaseolus vulgaris L.) are widely grown in Cameroon and play a key role in the fight against food insecurity, malnutrition and poverty. However, its cultivation encounters problems due to abiotic and biotic stresses, which leads to the use of synthetic fertilizers and pesticides, which cause significant damage to the environment and human health due to the presence of synthetics residues in the seeds, pods and in the leaves that are eaten. Promoting the use of natural products is becoming a necessity for organic and eco-responsible agriculture that limits contamination problems and improves people’s purchasing power. This study aims to assess the effect of biostimulants based on natural products on the growth and nutritional value of common bean (Phaseolus vulgaris L.). Bean seedlings from white variety (MEX-142) and red variety (DOR-701) were treated every seven days in the field from their pre-emergence, emergence and growth to their maturation under a randomized block experimental design. Six treatments and three repetitions with the biostimulants based on natural products and controls were thus performed and the agromorphological parameters were measured. After 120 days, the contents of growth biomarkers and defense-related enzymes were evaluated in leaves, while the contents of macromolecules, minerals and antinutrients were evaluated in seeds. These biostimulants significantly increased (P P < 0.0001) of antinutrients including oxalates, phytates, tannins and saponins in seeds compared to controls (T+ and T−). Treatment with biostimulants, in particular BS4, improves the performance of bean plants in the field as well as the biofortification of seeds regardless of the variety.

关键词： Phaseolus vulgaris L. Biostimulants Biofortification Growth and Defense Biomarkers Nutritional Value

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Synthesis, characterization and biological activities of Schiff bases derived from 2-hydroxy-3-nitrobenzaldehyde

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Journal of Chinese Pharmaceutical Sciences 2017年第12期26卷 858-871页

作者： Monisola Itohan Ikhile Marthe Carine Djuidje fotsing Charmaine Ardeme Jane Catherine Ngila Derek Tantoh Ndinteh Department of Applied Chemistry University of JohannesburgDoornfontein CampusPO 17011Johannesburg 2028South Africa Department of Chemistry University of JohannesburgP O Box 524Auckland ParkJohannesburg 2006South Africa

Four novel Schiff bases were synthesized by the condensation reaction of 2-hydroxyl-3-nitrobenzaldehyde with either benzothiazoles or benzimidazolamines. The compounds 1–4 were characterized by spectroscopic and analytical methods. The crystal structures of 6-methoxy-1,3-benzothiazol-2-amine and compound 2 are reported only. The 6-methoxy-1,3-benzothiazol-2-amine was found to crystallize in the orthorhombic crystal system in the space group Pbca, having eight molecules in the unit cell, while compound 2 was found to crystallize in the monoclinic crystal system in the space group P2_1/c. The biological activities of these compounds were investigated by evaluating their antibacterial, antifungal, antimalarial, anti-HIV and anti-trypanosomiasis activities. These compounds displayed very interesting antibacterial, antifungal, antimalarial, anti-trypanosomiasis, anti-HIV and low cytotoxicity activity against HeLa cells.

关键词： Schiff bases Biological activity Synthesis X-ray diffraction Characterization

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Early stage risk communication and community engagement(RCCE)strategies and measures against the coronavirus disease 2019(COVID-19)pandemic crisi

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Global Health Journal 2021年第1期5卷 44-50页

作者： Ernest Tambo Ingrid C.Djuikoue Gildas K.Tazemda Michael F.fotsing Xiao-Nong Zhou Higher Institute of Health Sciences University of the MountainsP.O.Box 208 BagangtéCameroon Prevention and Control NGOCameroon National Institute of Parasitic Diseases Chinese Center for Disease Control and Prevention

Coronavirus disease 2019(COVID-19)pandemic has proven to be tenacious and shows that the global commu nity is still poorly prepared to handling such emerging *** global solidarity in emergency preparedness and response,and the mobilization of conscience and cooperation,can serve as an excellent source of ideas and measures in a timely *** article provides an overview of the key components of risk communication and community engagement(RCCE)strategies at the early stages in vulnerable nations and populations,and highlight contextual recommendations for strengthening coordinated and sustainable RCCE preventive and emergency response strategies against COVID-19 *** solidarity calls for firming govemance,abundant community participation and enough trust to boost early pandemic preparedness and *** public RCCE response interventions needs crucially improving government health systems and security proactiveness,community to individual confinement,trust and resilience *** better understand population risk and vulnerability,as well as COVID-19 transmission dynamics,it is important to build intelligent systems for monitoring isolation/quarantine and tracking by use of artificial intelligence and machine learning systems *** and lessons learned from the international community is crucial for emerging pandemics prevention and control programs,especially in promoting evidence-based decision-making,integrating data and models to inform effective and sustainable RCCE strategies,such as local and global safe and effective COVID-19 vaccines and mass immunization programs.

关键词： Coronavirus disease 2019(COVID-19) Risk communication and communityengagement(RCCE) Response Trust Governance Pandemic Vaccination

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Selection Wind Farm Sites Based on GIS Using a Boolean Method: Evaluation of the Case of Cameroon

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Journal of Power and Energy Engineering 2021年第1期9卷 1-24页

作者： fotsing Metegam Isabelle Flora Njomo Donatien René Tchinda Oumarou Hamandjoda Environmental Energy Technologies Laboratory (EETL) University of Yaounde 1 Yaounde Cameroon Laboratory of Industrial Systems and Environment of the University of Dschang Dschang Cameroon Energetic Laboratory National Higher Polytechnic School Yaounde Cameroon

The negative effects of traditional methods of electricity generation on the environment have created the need for strategic planning and development of renewable and sustainable energy systems. This paper presents the analysis of the suitability of wind farm sites using a Boolean decision-making approach based on geographic information system (GIS) modeling. This analysis is based on different climatic, geographical, economic and environmental criteria such as wind resource, slope, accessibility by road, proximity to the electricity network and optimal distance from airports. The results of the study show that the most favorable sites are mainly located in the northern part of the country, particularly in the Far North and North regions. There are also favorable sites in the North-West, South-West, West, Littoral and very little in the South while the central and eastern regions are not suitable. This is mainly due to the tropical forest that covers the entire region of East Cameroon and the low wind speed in these regions which is the determining factor for the installation of wind farms. The appropriate land for the installation of wind farms is approximately 2.56% corresponding to an area of 11,602.494414 km

关键词： Wind Energy Boolean Method Geographic Information System (GIS) Cameroon Wind Farm

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Synthesis of 4-aminoantipyrine Schiff bases and their antimicrobial activities

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Journal of Chinese Pharmaceutical Sciences 2018年第11期27卷 753-766页

作者： Olatunde S.Oladeji Monisola I.Ikhile Carine M.D.fotsing Messai Mamo Patrick G.Ndungu Derek T.Ndinteh Department of Applied Chemistry Faculty of Science University of Johannesburg

Various compounds of 4-aminoantipyrine Schiff bases(M1–M12) were synthesized via a condensation reaction of 4-aminoantipyrine with different benzaldehydes through a conventional method of refluxing the mixture for 3–4 h. The synthesized Schiff bases were characterized by using elemental analyses, FT-IR, UV-Vis, Mass, 1 H and 13 C NMR spectroscopy. The antimicrobial activity of the synthesized Schiff bases was investigated against 12 bacterial strains(Mycobacterium smegmatis, Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Staphylococcus epidermidis, Klebsiella pneumonia, Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, Proteus vulgaris, Enterobacter aerogenes, and Pseudomonas aeruginosa), and antifungal activities were tested against seven fungal strains(Aspergillus flavus, Aspergillus carbonarious, Aspergillus parasiticus, Aspergillus fumigatus, Aspergillus niger, Fusarium verticillioides and Fusarium proliferatum). The antimicrobial activities of the synthesized compounds were compared with standard streptomycin and nalidixic acid. The results obtained from antibacterial assay indicated that M1–M12 inhibited potential growth of Proteus vulgaris with minimum inhibitory concentrations(MICs) ranging from 15.6–250 μg/mL compared with the standard nalidixic acid with an MIC of 500 μg/mL. Moreover, we could conclude that most of the tested compounds experienced mild to low activities at 15.6 μg/mL. Their activities could be attributed to their low concentration s. The antifungal analysis showed that the tested fungi were not sensitive to the prepared Schiff bases at the prepared concentration of 500 μg/mL. Therefore, we recommended further analysis on both cytotoxicity and minimum bactericidal concentration(MBC) to ascertain their potential effects against human cells.

关键词： 4-Aminoantipyrine Antibacterial Schiffbases Antifungal Synthesis Inhibition

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Achieving Polio Eradication: A Need for Innovative Strategies

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World Journal of Vaccines 2012年第1期2卷 46-49页

作者： Basile Keugoung richard fotsing Bart Criel Jean Macq Ministry of Public Health Yaounde Cameroon

Objective: The objective of this study was to analyze the current strategies used for eradicating wild polio viruses (WPV) and to propose some innovative strategies that may help to accelerate the progress towards polio eradication. Methods: We assessed the current strategies proposed by the World Health Organization, and the effectiveness of the current trivalent oral polio vaccine types 1, 2 and 3 (tOPV) schedule. Results: With the current schedule, tOPV is given four times to the child during his first year of life. After the four doses, 27%, 10% and 30% of children vaccinated are not immunized against WPV types 1, 2 and 3 respectively. In addition, low access to health care, insufficient funding of the routine immunization activities, and weak health systems hamper the tOPV coverage and the early detection of WPV cases for a rapid outbreak response. All these issues could explain the recurrence of WPV outbreaks, even in countries free of polio for many years. Therefore, we propose for countries of non-polio free regions, a new routine polio vaccination schedule composed of four doses of tOPV, followed by three doses of monovalent OPV type 1, and lastly by three doses of bivalent OPV types 1 and 3. With this schedule, of children fully vaccinated, 100%, 90% and 99% will be immunized against WPV types 1, 2 and 3 respectively. In addition, adequate funding for routine immunization activities and health system strengthening are proposed to accelerate the achievement of the polio eradication goal in a near future. Conclusions: The polio eradication goal is achievable. However, innovative strategies are urgently needed to improve the effectiveness and the efficiency of the routine polio immunization program.

关键词： Polio Eradication Vaccination Wild Polio Virus Immunization Program

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Exposure of the Population of Ngaoundere-Cameroon to Ionizing Radiation Related to Medical Diagnosis in 2018

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Open Journal of Radiology 2019年第2期9卷 125-138页

作者： Mathurin Neossi Guena Baudouin Djoumessi Nanfack Joseph Gonsu fotsing Department of Biomedical Sciences Faculty of Sciences University of Ngaoundéré Ngaoundéré Cameroon Imaging Service Ngaoundéré Regional Hospital Ngaoundéré Cameroon Faculty of Medicine and Biomedical Sciences University of Yaounde I Yaounde Cameroon Yaounde Gynaecology Obstetrics and Pediatrics Hospital Yaounde Cameroon

Background: Medical applications are the main source of exposure to ionizing radiation of human origin. Our objective was to determine the data on exposure to ionizing radiation of medical origin of the population of Ngaoundéré in 2018. Methodology: It was a cross-sectional descriptive study conducted within a period of one year, in the different hospitals of Ngaoundéré, with a functional medical imaging service. The variables studied were age, sex, type of examination, anatomical region and effective dose. The statistical analysis was performed using the Microsoft Office 2016 software, Sphinx V5;the effective dosage was calculated using the Internet Dose calculation Module. Results: In 2018, 4136 diagnostic acts using ionizing radiation were carried out;it concerned only conventional radiology with an average of 0.02 per capita. The total collective dose received by the population was 8300 mSv, and an average dose of 0.040 mSv per inhabitant. The proportion of the population that has actually benefited from a conventional radiology examination is 2.07%, an individual effective average dose of 2 mSv. The most frequent acts involved the thorax, limbs, spine and pelvis with respectively 53.9%;19.6%;14.3% and 6.7%. Acts involving the spine, pelvis and hip, skull and abdomen contributed to the majority of the collective effective dose respectively with 45.75%, 25.96%, 10.53% and 8.84%. The age group performing most exams in men is 25 to 49 and 25 to 54 in women;the number of acts is higher among men 2457 (59.4%) acts compared to women 1679 (40.6%) acts. The collective dose per sex is higher among women with 4487.22 mSv (54.06%) compared to men with 3812.98 mSv (45.94%). Conclusion: Only 2.07% of population of Ngaoundere benefited from a conventional radiology examination in 2018 with an individual effective average dose of 2 mSv. The annual per capita number of acts is 0.02 and annual per capita effective dose is 0.040 mSv in Ngaoundéré in 2018.

关键词： Exposure Ionizing Radiation Conventional Radiology City of Ngaoundéré 2018

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