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Prevalence of Enteric Pathogens Associated with Infections among Table Egg Consumers in Some Primary Health Establishments in the Center Region of Cameroon

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Advances in Infectious Diseases 2024年第3期14卷 606-619页

作者： Mariane Lucie Ngueguim Bernard Viban Tangwa Victor Ngu Ngwa Albert Ngakou Abdoulmoumini Mamoudou School of Veterinary Medicine and Sciences University of Ngaoundere Ngaoundere Cameroon Department of Veterinary Medicine University of Buea Buea Cameroon Faculty of Sciences University of Ngaoundere Ngaoundere Cameroon

Method: In Cameroon limited data are available regarding the prevalence of enteric bacteria associated with table egg consuming infections. As such, a situational-based study was performed in patients with complains of stomach disorders after egg consumption. Data related to sociodemographic characteristics and other factors were collected using a structured based questionnaire. Stool culture of utmost importance in stomach disorders patients and serum were collected for typhoid serological test. Results: A total of 207 participants took part in the survey, Results indicated nontyphoidal Salmonella infections were highest in the 3 areas of study with Mfoundi (73.44%) having the highest level of infection compared to other bacterial infection. other enteric bacteria associated to this infection were E. coli serotype 157, Aeromonas, Citrobacter freundii, Enterobacter cloaca and typhi salmonella. Meanwhile salmonelosis caused by typhic salmonella had highest prevalence in the Lekie Division (13.11%) as a result of poor hygienic practices associated with the conservation and preparation of eggs, Stool culture was observed to detect more positive cases in the diagnosis of typhoid fever than Widal test, but with no statistically significant (p > 0.05) difference between the stool culture and Widal test in the 3 areas of study. Conclusion: this study revealed that egg consumers are pruned to enteric bacterial and salmonella infections depending on how and where egg is consumed.

关键词： Enteric Pathogens Table Eggs Consumption Center Region Cameroon

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A Maintenance Service Improvement Approach Based on Queue Networks: Application

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Open Journal of Applied Sciences 2024年第2期14卷 425-440页

作者： Aslain Brisco Ngnassi Djami Wolfgang Nzié Boukar Ousman Joseph Nkongho Anyi Ulrich Ngnassi Nguelcheu Department of Fundamental Sciences and Techniques of Engineer Chemical Engineering and Mineral Industries School University of Ngaoundere Ngaoundere Cameroon Laboratory of Mechanics Materials and Photonics National School of Agro-Industrial Sciences University of Ngaoundere Ngaoundere Cameroon Department of Electrical Engineering Energy and Automation National School of Agro-Industrial Sciences University of Ngaoundere Ngaoundere Cameroon Laboratory E3M Faculty of Industrial Engineering University of Douala Douala Cameroon Department of Physics Faculty of Science University of Ngaoundere Ngaoundere Cameroon

The quest to increase the performance of production systems that have become complex leads to the transfer to the maintenance function of the responsibility of guaranteeing the availability of such systems. Also, we will never stop saying that maintenance must integrate into all of the company’s initiatives, to affirm its role, which is to ensure greater availability and sustainability of the means of production. The objective of this paper is to evaluate the reliability and availability of a system without knowing the distribution law of the operating times. Among the methods for evaluating dependability criteria (Fault Trees, Petri Nets, etc.), we are interested in queues that have the advantage of taking into account functional dependencies, thus allowing a quantified optimization of maintenance. Indeed, queues make it possible to model parallel or sequential processes, implementing operations taking place at the same time or one after the other, meeting the needs of modeling production systems. The main result of this paper is the study of the influence of availability on the reliability of a multi-state production system.

关键词： Markov Chains Queues Availability Reliability Maintenance

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Evaluation of the Reliability of a System: Approach by Monte Carlo Simulation and Application

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Open Journal of Applied Sciences 2024年第3期14卷 721-739页

作者： Aslain Brisco Ngnassi Djami Jean Bosco Samon Boukar Ousman Ulrich Ngnassi Nguelcheu Wolfgang Nzié Guy Edgar Ntamack Bienvenu Kenmeugne Department of Fundamental Sciences and Techniques of Engineer Chemical Engineering and Mineral Industries School University of Ngaoundere Ngaoundere Cameroon Department of Mechanical Engineering National School of Agro-Industrial Sciences University of Ngaoundere Ngaoundere Cameroon Department of Electrical Engineering Energy and Automation National School of Agro-Industrial Sciences University of Ngaoundere Ngaoundere Cameroon Department of Physics Faculty of Science University of Ngaoundere Ngaoundere Cameroon Department of Industrial and Mechanical Engineering National Advanced School of Engineering University of Yaounde I Yaounde Cameroon

The objective of this paper is to evaluate the reliability of a system in its different states (absence of failures, partial failure and total failure) and to propose actions to improve this reliability by an approach based on Monte Carlo simulation. It consists of a probabilistic evaluation based on Markov Chains. In order to achieve this goal, the functionalities of Markov Chains and Monte Carlo simulation steps are deployed. The application is made on a production system. .

关键词： Evaluation Reliability Monte Carlo Markov Chain

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Extraction, Production and Quality Evaluation of Margarine from Oil Extracted from Waste Biomass Peels of Avocado and Virgin Coconut Oil, Using Chitosan from Reared Shells as Preservative

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Journal of Agricultural Chemistry and Environment 2024年第1期13卷 142-168页

作者： Suh-Ndale Svetlana Miyanui Pride Ndasi Ngwasiri Wiyeh Claudette Bakisu Muala Noumo Thierry Ngangmou Wilson Agwanande Ambindei Martin Benoit Ngassoum Department of Nutrition Food and Bioresource Technology College of Technology University of Bamenda Bamenda Cameroon Department of Process Engineering ENSAI University of Ngaoundere Ngaoundere Cameroon Department of Applied Chemistry ENSAI University of Ngaoundere Ngaoundere Cameroon

The production and consumption of avocado pears generates tons of wastes, mainly the pear peels which are usually discarded, although they have been reported to contain important phyto-chemicals with biological activities. The adverse health effect associated with the consumption of saturated lipid based foods has ignited research on reformulation of lipid based foods to eliminate Trans Fatty Acids (TFAs). This study was thus aimed at the extraction and characterization of oil from Avocado Peels (APO) and evaluation of the quality of margarine produced from it. Five verities of pear were used for oil extraction by soxhlet method and physiochemical, oxidative, functional and antioxidant characterization was done. Margarines were formulated using a central composite design using oil blends of APO and Virgin Coconut Oil (VCO) with an oil ratio of 10:90, 40:60, 70:30 respectively, varied blending speed, blending time, and chitosan concentration. Samples were characterized and the effect of process parameters on the physiochemical and functional properties of the margarine studied. Optimized conditions were used to produce samples for sensory evaluation. Color, spreadability, aroma, taste and general acceptability was evaluated using ranking difference test. The results showed that the yield, density, and iodine values of APOs oils ranged from 14.91 ± 0.18 to 11.76 ± 0.46;0.93 ± 0.001 to 0.99 ± 0.1;46.63 ± 1.70 to 52.4 ± 0.63, their acid values, TBA and PV values ranged from 1.42 ± 0.39 to 1.97 ± 0.5;0.11 ± 0.002 to 0.18 ± 0.04;and 2.72 ± 0.14 to 4.43 ± 0.36 respectively, with Brogdon avocado peel variety having the overall best properties prepared blends of trans-free APO margarines showed that increase in APO ratio decreased melting point, increased oxidative stability and reduced moisture content of margarine samples. Chitosan addition leads to decrease moisture content and increase functional properties. VCO lead to increase in phenolic and flavonoid content of the m

关键词： Food Waste Avocado Peels Extraction Oil Biological Activity Margarine Chitosan

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Optimal Sizing and Power Losses Reduction of Photovoltaic Systems Using PVsyst Software

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Journal of Power and Energy Engineering 2024年第7期12卷 23-38页

作者： Andre Boussaibo Armel Duvalier Pene Kitmo Institute of Technology University of Ngaoundere Ngaoundere Cameroon National Advanced School of Engineering of Maroua University of Maroua Maroua Cameroon

This paper presents a method for optimizing a grid-connected photovoltaic system through an LCL filter. An algorithm based on particle swarm optimization (PSO) is used to determine the number of batteries, the number of panels in series and in parallel, as well as to evaluate the joule losses due to cable heating and the switching losses of the multilevel inverters. This system is applied to a village named YAGOUA, located in the far north of Cameroon. The evaluation of the Joule effect and the switching losses as well as the regulation of the voltage level at the point of common coupling (PCC) are carried out in PVsyst and Matlab software, then at IEEE 33 bus. This algorithm reduced the Joule losses to 1.2% and the switching losses to 2.2%. A power of 210.4 MWh is produced, to be injected in the electrical network via an LCL filter. The THD calculation gave a rate of 3.015% in accordance with the 519 standards. Synchronization through the Phase Locked Loop (PLL) is performed. After the power was injected into the grid, the voltage and current remained in phase, showing the power factor correction and the efficiency of the filter. According to NASA meteorological data, the locality of YAGOUA gives the global solar irradiation forecast of 6.8 kW/m2.

关键词： Five Level Inverter LCL Filter MPPT Power Losses PVsyst

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Comparative Study of the Widal Test against Stool Culture in the Diagnosis of Suspected Cases of Typhoid Fever in Some Low Income Communities in the Adamawa Region of Cameroon

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Journal of Biosciences and Medicines 2024年第6期12卷 178-190页

作者： Mariane Lucie Ngueguim Bernard Viban Tangwa Victor Ngu Ngwa Jules Romain Ngueguim Abdoulmoumini Mamoudou School of Veterinary Medicine and Sciences University of Ngaoundere Ngaoundere Cameroon Department of Veterinary Medicine University of Buea Buea Cameroon Institute de Recherhe Agricole pour le Development (IRAD) Ngaoundere Cameroun

Introduction: Infectious diseases constitute a major concern of public health in developing countries. Facilities and well trained staff have been shown to be one of the major obstacles in the rapid and quality diagnosis of these diseases. As such, we carried out an analysis to compare the Widal test and stool culture to identify febrile patients with Salmonella infection. Method: A cross sectional study was conducted to diagnose salmonella infection with out-patients who demonstrated signs of salmonella infection. Serum was harvested from blood collected from 368 (Vina = 234, Mayo Banyo 65, and Djerem = 69) patients accompanied by stool, Widal test was conducted on the spot and stool was taken to a reference laboratory for culture using standard microbiological methods, sociological set up was calculated in percentages, prevalence was calculated using excel while statistical difference was calculated using SPSS. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated to compare the Widal test against stool culture. Results: A total of 368 (50.8% females and 49.2% males) participants took part in the survey. Salmonella prevalence (66.24%) in stool culture in the Vina division was significantly different (p 0.05). The sensitivity,specificity, PPV, and NPV of slide agglutination test against stool culture varied from different areas (Vina: 51.6%, 73.62%, 79.21% and 43.61%;Mayo Banyo: 60.53%, 77.78%, 79.31% and 58.33%;Djerem: 53.18%, 83.73% 73.91% and 67.39%) respectively. Slide agglutination test has a fair agreement with the stool culture (kappa, Vina = 0.202;Mayo Banyo = 0.37 and Djerem = 0.38). Conclusion: Generally, in the three areas of study, the Widal test had a fair correlation with the stool culture;This means the Widal test should not be used alone but in combination with stool culture in the detection of salmonella infections.

关键词： Salmonella Infections Stool Culture Widal Test Adamawa Region Cameroon

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Effect of Aqueous Extract of Boscia senegalensis on Hyperglycemia, Hyperlipidemia and Oxidative Stress Induced in Rats

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Journal of Diabetes Mellitus 2024年第1期14卷 49-68页

作者： Faustin Dongmo Elie Baudelaire Djantou Alcherif Hamid Mahamat Selestin Sokeng Dongmo Nicolas Njintang Yanou Department of Biological Sciences Faculty of Science University of Ngaoundere Ngaoundere Cameroon Department of Food Science and Nutrition ENSAI University of Ngaoundere Ngaoundere Cameroon Department of Biomedical and Pharmacetical Sciences National Higher Institute of Science and Techniques of Abeche Abeche Chad

Boscia aqueous extract. senegalensis on hyperglycemia, hyperlipidemia and oxidative stress induced in rats. The aqueous extract was prepared from B. senegalensis seed powders under the extraction conditions: time (10 min), temperature (55˚C) and the ratio of mass of flour/volume of water (3/10 g/mL). Male wistar rats aged 6 to 8 weeks were acclimated and divided into 8 groups of 5 rats each: two normal control groups which received a normal standard diet (3810 kcal/kg), and six test groups which were subjected to a hyperlipidemic diet (5310 Kcal/kg). All groups of animals were fed in this manner for 8 weeks to induce hyperglycemia, hyperlipidemia and oxidative stress. After induction the animals were treated either with distilled water for the normal and negative control groups or with atorvastatin for the positive control group or with the extract of B. senegalensis. (125, 250 and 500 mg/kg) for the test groups. Fasting blood glucose was taken every 7 days during induction. After sacrifice, biochemical and oxidative stress parameters were measured. The aqueous extract of B. senegalensis significantly decreased (p B. senegalensis at a dose of 500 mg/kg has the capacity to reduce blood sugar, improve the quality of the lipid profile and reduce oxidative stress. Thus, the results reveal that the aqueous extract of B. senegalensis has powerful hypoglycemic, hypolipidemic and antioxidant properties.

关键词： Boscia Senegalensis Hypoglycemic Hypolipidemic Hyperlipidemic Diet An-tioxidant

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Optimization of Cellulose Nanocrystal Isolation from Ayous Sawdust Using Response Surface Methodology

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Journal of Materials Science and Chemical Engineering 2024年第1期12卷 36-55页

作者： Tchigo Alifa Hamida Aminatou Oumar Said Jean-Bosco Tchatchueng Department of Chemical Engineering School of Chemical Engineering and Mineral Industries University of Ngaoundere Ngaoundere Cameroon Department of Applied Chemistry National Advanced School of Agro-Industrial Sciences University of Ngaoundere Ngaoundere Cameroon Department in Charge of Coordination and Valorisation of Research National Advanced School of Engineering University of Yaounde 1 Yaounde Cameroon

This study focuses on the extraction of cellulose nanocrystals (CNC), from microcrystalline cellulose (MCC), derived from Ayous sawdust. The process involves multiple steps and a large amount of chemical products. The objective of this research was to determine the effects of factors that impact the isolation process and to identify the optimal conditions for CNC isolation by using the response surface methodology. The factors that varied during the process were the quantity of MCC, the concentration of sulfuric acid, the hydrolysis time and temperature, and the ultrasonic treatment time. The response measured was the yield. The study found that with 5.80 g of microcrystalline cellulose, a sulfuric acid concentration of 63.50% (w/w), a hydrolysis time of 53 minutes, a hydrolysis temperature of 69˚C, and a sonication time of 19 minutes are the ideal conditions for isolation. The experimental yield achieved was (37.84 ± 0.99) %. The main factors influencing the process were the sulfuric acid concentration, hydrolysis time and temperature, with a significant influence (p < 0.05). Infrared characterization results showed that nanocrystals were indeed isolated. With a crystallinity of 35.23 and 79.74, respectively, for Ayous wood fiber and nanocrystalline cellulose were observed by X-ray diffraction, with the formation of type II cellulose, thermodynamically more stable than native cellulose type I.

关键词： Ayous Sawdust Lignocellulosic Waste Isolation Cellulose Nanocrystals Optimization Response Surface Methodology

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Joint Management of Shared Resources, Issues and Conflicts of the Nso and Oku Tribes in the Ngongbaa Montane Forest Area, NWR of Cameroon

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Natural Resources 2024年第6期15卷 149-172页

作者： Jean-Louis Tatah Elvis Kah Department of Geography Faculty of Arts Letters and Social Sciences University of Yaounde I Yaounde Cameroon School of Geology and Mining Engineering University of Ngaoundere Ngaoundere Cameroon

Wherever people live together in or near homelands that harbour joint natural resources such as forest, water, minerals, oil etc., they must collaborate, co-exist and share these resources irrespective of their genetic, social, cultural, and political peculiarities. This is not always the case when self-interest, ethnic divisions, elitist politics, economic interest and power tussle set in. The Nso and Oku people who reside in the Ngongbaa Forest area constitute an example of joint management of resources where at one period, their relationship over the management of the Oku Mountain Forest was cordial and at another, the relationship became conflictive. This study was designed to study the influence of the KIFP forest management policies on the Nso indigenous forest Management system in Ngongbaa Forest, and its implications. The data collected for the study was secured through the administration of a questionnaire to residents of 10 villages adjacent to the Ngongbaa Forest, and forest users who carried out livelihood activities there between 1963 and 2015. These forest user groups include beekeepers, rat trappers, grazers, mushroom gatherers, ground honey/tree honey harvesters, carvers, etc. The investigation also extended to the traditional leaders of Nso and Oku who are in charge of the land tenure systems. The findings show that the Oku Mountain Forest is jointly owned by the Nso and Oku people. The Nso own the eastern half of the forest known as Ngongbaa Forest while the Oku own the western half, known as the Kilum Forest. The cordial relationship that existed between these people ensured the conservation of the forest. But the conflicts that later set in, especially due to the creation of the Kilum Mountain Forest Project in 1987 later changed to the Kilum Ijim Forest Project (KIFP) in 1992 sidelined the local communities which was contrary to the dispositions of the new Cameroon forest law enacted in 1994. Thus, the indigenous conservation practices became ig

关键词： Conflict Joint Management Shared Resources Ngongbaa Kilum Conservation

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ω-3 Rich Tetracarpidum conophorum Oil Exhibits Better Prevention Effects for Cardiovascular Risk Factors than Corn Oil in Adult of Albinos Wistar Male Rats

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Food and Nutrition Sciences 2024年第8期15卷 663-680页

作者： Nzali Horliane Ghomdim Kenfack Laurette Blandine Mezajoug Eric Serge Ngangoum Stève Djiazet Clergé Tchiegang Bioprocess Laboratory Department of Food Process and Quality Control University Institute of Technology University of Ngaoundere Adamaoua Cameroon School of Agriculture and Natural Resources Catholic University Institute of Buea Buea Cameroon Department of Food Sciences and Nutrition National Advanced School of Agro-Industrial Sciences (ENSAI) University of Ngaoundere Ngaoundere Cameroon

Cardiovascular diseases are serious pathologies that affect an increasing number of people. Several preventive measures are generally used, including supplementing of oils in foods. Our objective was to compare the effects of Tetracarpidum conophorum oil (TC) and corn oil (CO) on serum lipid profiles of normal male rats. 42 Wistar rats were divided into 7 groups. Diets included TC oil (groups TC5, TC10 and TC20) and corn oil (groups CO5, CO10 and CO20) in proportions of 5%, 10% and 20%, with a control group (T). After 5 weeks of feeding, several parameters were measured during and after the study, including body weight, food intake and organ weights (kidney, liver and fat). Lipid profiles (total cholesterol, TG, HDL and LDL), glucose and protein levels were measured in the serum. The increase in body mass was inversely proportional to the amount of oil in the food. The decrease in body mass and adiposomatic index of group TC10 was significant (p < 0.05) compared with the other groups. The lowest glycaemia (64.17 ± 5.14 mg/dl) was noted with the diet containing 20% TC oil. A significant reduction in total cholesterol, LDL fraction and blood triglycerides was observed in the groups supplemented with TC and corn oils compared to controls. Results were also more beneficial for the TC10 group. HDL-cholesterol levels were significantly higher (p < 0.05) in the oil-supplemented groups than in the control group. Castelli’s risk indices decrease significantly (p < 0.05) with increasing oil content for TC. The oils had no impact on blood protein contents. One can conclude that a diet containing 10% crude oil from TC kernels could prevent or alleviate cardiovascular diseases and glycemia.

关键词： Tetracarpidium conophorum Oil ω-3 Corn Oil Lipid Profiles Glycemia

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