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Journal of Environmental Protection 2014年第3期5卷 193-199页

作者： Wagner de S.Pereira alphonse Kelecom Juliana R.de S.Pereira Multidisciplinary Group of Radioprotection(GMR) Servico de RadioprotecaoUnidade de Tratamento de MinerioIndustrias Nucleares do BrasilCaldasBrazil Laboratory of Radiobiology and Radiometry Pedro Lopes dos Santos(LARARA-PLS) Group of Environmental Themes Assessment(GETA)Universidade Federal Fluminense(UFF)NiteroiBrazil Interdisciplinary Under-Graduation in Science and Technology Universidade Federal de AlfenasPocos de CaldasBrazil

The radium isotopes 226Ra and 228Ra were analyzed in surface water at six points in the neighborhood of a mine of phosphate, associated with uranium, in the region of Santa Quitéria, state of Ceará, Brazil. Water samples were collected during twenty months, filtered and the concentrations of activity determined in the soluble and particulate phases. The results were analyzed using the Principal Component Analysis (PCA) for ordination of environmental data, and also by ANOVA, Tukey and Z tests to compare sets of data considering the radionuclides, the two analyzed phases and the six collecting points. The PCA identified four groups that included all collecting points, using aggregation features such as radionuclide and analyzed phase. The first group is composed by the samples of 226Ra in the soluble phase;the second group by samples of 226Ra in the particulate phase;the third one by 228Ra in the soluble phase, and finally, the fourth group by 228Ra in the particulate phase. This last group has two discrepant points (01 and 06). Statistical analysis identified differences between the concentrations of activity of radionuclides (228Ra higher than 226Ra) and in analyzed phases (soluble phase higher than the particulate one) but showed no differences between sampled points.

关键词： Radioecology Environmental Radioprotection NORM Mining Radium Isotopes PCA

Computational Study of the Interactions between Antimalarial Chemotherapies with Folate Pathway Receptors and Telomerase Reverse Transcriptase

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Computational Chemistry 2021年第3期9卷 197-214页

作者： Djogang Lucie Karelle Forlemu Neville Emadak alphonse Njabon Njankwa Eric Issofa Patouossa Nenwa Justin Physical and Theoretical Chemistry Laboratory Faculty of Science University of Yaounde I Yaounde Cameroon Applied Inorganic Chemistry Laboratory Faculty of Science University of Yaounde I Yaounde Cameroon School of Science & Technology (Chemistry) Georgia Gwinnett College Lawrenceville USA

Malaria is a life-threatening disease responsible for half a million death annually, and with nearly half of the world’s population at risk. The rapid drop in observed cases of malaria in the last two decades has been due to a combination of preventive and therapeutic remedies. However, the absence of a vaccine, new antimalarial chemotherapies and increased parasitic resistance have led to a plateau of infections and renewed research interest in target human and Plasmodium (the malaria parasite) receptors and new drugs. In this study, the impact of mutation on the affinity on antimalarial drugs with the bifunctional enzyme complex, dihydrofolate reductase (DHFR) is explored. In addition, homology modeling is used to build the three-dimensional models of the enzymes Plasmodium telomerase reverse-transcriptase (pf-TERT) and Plasmodium dihydropteroate synthetase (pf-DHPS) to determine their affinity with antimalarial drugs. The interaction energies and stable complexes formed between these enzymes and antimalarial drugs (chloroquine, artemisinin, primaquine, pyrimethamine, sulfadoxine and pentamidine) were modelled using AutoDock vina. Our data indicate that pf-TERT and pf-DHPS form stable complexes with the antimalarial ligands with affinity ranging from 𕒸.0 to 𕒺.9 kcal/mol. The affinity with crystal structures of DHFR receptors was higher ranging from 𕒺.0 to 󔼒.0 kcal/mol. The affinity to DHFR also decreases with the mutation a confirmation of the source of resistance. The highest affinity interaction for all the receptors modeled is observed with Artemisinin a benchma

关键词： Malaria Binding Energy Dihydrofolate Reductase Dihydropteroate

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Contribution for Efficient Planning of Millimeter Wave Frequencies: Case of the 80 GHz E-Band for High-Speed Broadband Transmissions

作者： (法)都德(alphonse Daudet)

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Journal of Computer and Communications 2023年第11期11卷 111-148页

作者： Patrick Dany Bavoua Kenfack alphonse Binele Abana Emmanuel Tonye Paul-Salomon Ngohe-Ekam Jacques Nyemb Nga Department of Electrical and Telecommunications Engineering National Advanced School of Engineering of Yaounde University of Yaounde I Yaounde Cameroon

Due to the very high demand for Internet data capacity from mobile and fixed customers as well as the saturation of conventional frequency bands by numerous services, many countries have opened the E band, for broadcasting services. E-band involves the creation of a significant number of links in a given area. The present work addressed the problem that arises in the context of transmission is that of assigning the frequencies of this band to these multiple transmission links. The aim of this work is to study and plan the radio links of the 80 GHz frequency and to implement them in a tool in order to define an optimal distribution on the telecommunications network by guaranteeing maximum flow of data traffic while minimizing the interference. The contribution of this work is part of its unique subject: the planning of E-band frequencies for improving the quality of service of transmission in the network of telecommunications operators. Also, it intends to contribute to the resolution of unsatisfied situations of poor planning of E-band radio frequencies in telecommunications networks. With the aim of opening several opportunities for alternative high-speed data transport solutions, our work has helped prove that E-band transmission links are very efficient with capacities in the gigabyte range.

关键词： Radio Beams E-Band Frequency Planning Microwave

Germination and Early Seedling Growth of Moringa oleifera Lam with Different Seeds Soaking Time and Substrates at the Yongka Western Highlands Research Garden Park (YWHRGP) Nkwen-Bamenda, North-West Cameroon

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American Journal of Plant Sciences 2016年第15期7卷 2173-2185页

作者： Bernard Palmer Kfuban Yerima Grace Mbakpor Ayuk Roger Kogge Enang Nicole Guehjung Yanick alphonse Tiamgne Department of Soil Science University of Dschang Dschang Cameroon Department of Crop Production University of Dschang Dschang Cameroon Ministry of Agriculture and Rural Development West Region Cameroon

Moringa oleifera is a multipurpose tree used to remedy problems related to food insecurity and soil fertility degradation. Proper husbandry of this crop is contingent on the use of seedlings of good quality. This study aimed at assessing the germination and early seedling growth with different soaking durations and substrates composition. The seeds were obtained from the Far North region of Cameroon. A randomized complete block design with three replications was used. Two factors were tested;soaking duration with 4 treatment levels of 0 day, 4 days, 8 days and 12 days and substrates with 8 treatment levels: 100% soil, 75% soil + 25% poultry manure (PM), 50% soil + 50% PM, 25% soil + 75% PM, 100% sand, 75% sand + 25% PM, 50% sand + 50% PM and 25% sand + 75% PM. Germinated seeds and growth parameters were collected after every 5 days. The results showed that soaking duration and substrate composition influence germination and initial development of M. oleifera (p ≤ 0.05). At 25 days after soaking (DAS), soaking durations of 0 day (68.7%) and 8 days (53.1%) showed the highest germination percentages while seeds soaked for 12 days occupied the least position with 37.5%. At the same time, 75% soil + 25% PM (68.7%), 100% sand (64.5%) and 100% soil (60.5%) with the unsoaked seeds showed the highest germination percentages. The least germination percentages were represented by 50% sand + 50% PM and 25% sand + 75% PM with 35.5% and 27%, respectively. Unsoaked seeds with the substrates of 50% soil + 50% PM are the best practice for M. oleifera seedling production in the nursery.

关键词： Soaking Substrate Composition Germination Initial Growth Western Highlands

Optimization of Mobile Network Radio Coverage by Automating Radio Parameter Updates Using Parsing

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Journal of Computer and Communications 2023年第4期11卷 79-102页

作者： Patrick Dany Bavoua Kenfack alphonse Binele Abana Emmanuel Tonye Nadège Laure Bemehemie William Tchofo Tchouleko Department of Electrical and Telecommunications Engineering National Advanced School of Engineering of Yaoundé University of Yaoundé I Yaoundé Cameroon

The present work aims is to propose a solution for automating updates (MAJ) of the radio parameters of the ATOLL database from the OSS NetAct using Parsing. Indeed, this solution will be operated by the RAN (Radio Access Network) service of mobile operators, which ensures the planning and optimization of network coverage. The overall objective of this study is to make synchronous physical data of the sites deployed in the field with the ATOLL database which contains all the data of the coverage of the mobile networks of the operators. We have made an application that automates, updates with the following functionalities: import of radio parameters with the parsing method we have defined, visualization of data and its export to the Template of the ATOLL database. The results of the tests and validations of our application developed for a 4G network have made it possible to have a solution that performs updates with a constraint on the size of data to be imported. Our solution is a reliable resource for updating the databases containing the radio parameters of the network at all mobile operators, subject to a limitation in terms of the volume of data to be imported.

关键词： Radio Parameters Parsing ATOLL Database OSS NetAct ETL

Prevalence of Tobacco Use and Associated Factors among Adults in Benin in 2015: Results of the National Survey of Non-Communicable Disease Risk Factors

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Open Journal of Epidemiology 2018年第3期8卷 130-144页

作者： Alexandrine Houinato Roch Christian Johnson alphonse kpozehouen Fernand Guedou Christophe Houssou Dismand S. Houinato Inter Faculty Center of Training and Research in Environment for Sustainable Development University of Abomey-Calavi Cotonou Benin Regional Institute of Public Health University of Abomey-Calavi Cotonou Benin Laboratoire d’Epidémiologie des Maladies Chroniques Et Neurologiques (LEMACEN) Faculty of Health Sciences Université d’Abomey-Calavi Cotonou Benin Faculty of Humanities and Social Sciences University of Abomey-Calavi Cotonou Benin

Introduction: Tobacco use and exposure to tobacco smoke are one of the most preventable causes of death and disability worldwide. The risk is even higher among daily tobacco consumers. The World Health Organization (WHO) recommended that surveillance of major risk factors for non- communicable diseases (NCDs), such as smoking, be imperative to predicting the future burden of NCDs, identifying adequate interventions to decrease future burden and monitor trends. In 2015, a survey on NCD risk factors was conducted in Benin to estimate the prevalence of major NCD risk factors. We analyzed the data from this survey to estimate the prevalence and risk factors associated with daily tobacco consumption in Benin. Methods: A nationwide representative sample of the population was constituted in the 12 departments of Benin. The WHO STEPS wise tool was used to collect data on behavioral and demographic characteristics, including daily tobacco consumption. Tobacco consumption was subdivided into three categories: The daily consumption of tobacco, the daily consumption of smoked tobacco and non-smoked tobacco. Multivariate analysis through the weighted logistic regression was used to identify potential factors associated with daily consumption of tobacco. Results: Over the 5.126 surveyed subjects, 7.49% were daily tobacco consumers, with 3.85% being daily users of smoked tobacco and 4.36% being daily consumers of non-smoked tobacco. Men were more likely to be daily consumers of tobacco compared to women (OR = 7.42;95%CI = [4.98;11.06]). Compared to respondents aged 18 to 24, those aged 45 to 54 were five times more likely to consume tobacco (OR = 5.58;95%IC = [2.71;11.47]). Respondents residing in the departments of Atacora, Couffo and Borgou were respectively 4.28 times, 3.93 times and 2.63 times more likely to consume tobacco compared to those residing in the department of Alibori. Respondents with no education were more likely to consume tobacco daily compared to respondents wh

关键词： Tobacco Non Communicable Diseases STEP Wise Benin

Monitoring Forest Cover Change and Fragmentation Using Remote Sensing and Landscape Metrics in Nyungwe-Kibira Park

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Journal of Geoscience and Environment Protection 2016年第11期4卷 13-33页

作者： alphonse Kayiranga Alishir Kurban Felix Ndayisaba Lamek Nahayo Fidele Karamage Abdimijit Ablekim Haiwen Li Osman Ilniyaz State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi China University of Chinese Academy of Sciences (UCAS) Beijing China University of Lay Adventists of Kigali (UNILAK) Kigali Rwanda

The objective of this study was to evaluate forest cover change and forest degradation in Nyungwe-Kibira Park, a natural reserve straddling Rwanda and Burundi from 1986 to 2015. Landsat TM, ETM+ and 8OLI images of 30 m spatial resolution were used as primary datasets. Geographic Information System (GIS) techniques were used for forest cover mapping and landscape metrics were calculated by using FRAGSTATS software. Classification and change analysis of forest cover type and landscape patterns analysis were carried out. In addition, to analyze the correlated external disturbances, the buffer zone of 5 Km was delineated outside the boundary of Nyungwe-Kibira Park. The results revealed that in among 5 land cover classes considered within the Park, the dominant one was dense forest class covering over 70% of the entire Park area while in the buffer zone cultivated and open land dominated at over 90% between the years 1986 and 2015. Change detection highlighted that within Nyungwe-Kibira forest, approximately 0.27% (4.97 Km2) of forest cover was cleared while 0.07% (1.22 Km2) was regenerated annually. In the buffer zone, the annual cleared forest cover was about 0.76% (13.02 Km2). The five landscape indices chosen at class level indicated a considerable fragmentation of forest inside the Park and the highest fragmentation in the buffer zone. Indeed, these results shed a bleak image over the future of the Nyungwe-Kibira forest that should be helpful for the policy-makers and managers of these natural parks to establish adequate policies to mitigate the forest loss and degradation by implementing quick and effective solutions.

关键词： Burundi Forest Management Landscape Analysis Nyungwe-Kibira Park Remote Sensing Rwanda

Quantifying Forest Loss in the Mbalmayo Forest Reserve (Center Region, Cameroon)

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Journal of Geoscience and Environment Protection 2022年第9期10卷 271-288页

作者： Mingang Danielle Liliane Ngueguim Jules Romain Momo Solefack Marie Caroline Tchongouang Abigaelle Tientcheu Tcheugoue alphonse Loic Unité de Recherche de Botanique Appliquée (URBOA) Department of Plant Biology Faculty of Science University of Dschang Dschang Cameroon Agricultural Research Institute for Development (IRAD) Yaoundé Cameroon Department of Geography Faculty of Letters and Humanities University of Dschang Dschang Cameroon Department of Geography Faculty of Arts Letters and Humanities University of Yaoundé I Yaoundé Cameroon

This study was carried out in the forest reserve of Mbalmayo, Center Region of Cameroon, with the aim to analyze the dynamics of land use/land cover (LULC) changes over the past 30 years. The databases used were made up of 3 Landsat satellite images (5TM of 1990, 7ETM+ of 2005 and 8OLI of 2020). The satellite images were processed using ArcGIS and Erdas Imagine software. Ethnobotanical surveys were conducted to investigate the relationships between the local population and the forest reserve. The Mbalmayo forest reserve is consisted of seven main land cover namely: mature secondary forest, young secondary forest, savanna, fallows and crops, built, bare soil and water surface. The dynamics of the forest cover undergoes more significant changes between the years 1990-2005 with losses estimate at 4762 ha compared to the years 2005-2020 (2231 ha), with a marked decrease in the area of dense forests. This regression is much more important in dense forest vegetation. The forest cover lost 6993 ha (26.92%) of its surface, which corresponds to an average rate of deforestation of 233.1 ha/year. The survey revealed the need for NTFPs for the Mbalmayo reserve forest populations. Indeed, all respondents agreed that they use non-timber forest products from the forest, mainly for medication (37%), wood (34%) and food (24%). Therefore, it becomes urgent to redefine a management plan for the Mbalmayo forest reserve which will define how the forest must be managed in order to avoid the loss of large areas of forests disappearing each year under the human action, which exerts pressure on forest species, thus leading to their possible disappearance.

关键词： Mbalmayo Forest Reserve Satellite Images Ethnobotany Land Use/Land Cover Change