University of Buea
  • Buea, South West Region, Cameroon
Recent publications
Background Central nervous system (CNS) infections are serious and debilitating diseases with significant mortality, and high prevalence in the context of human immunodeficiency virus (HIV) pandemic in Africa. However, their diagnosis remains challenging due to outdated technical platform. We aimed to determine the frequency of CNS infection and to describe the epidemiological, clinical and outcome of this at the Douala General Hospital (DGH), Cameroon. To carry out this study, we collected the medical records of patients hospitalized for CNS infections in the internal medicine department of DGH from January 2015 to December 2019. Results Among 8430 files reviewed, 336 cases of CNS infection were identified giving a frequency of CNS infection of 3.99% among which 204 files were included in the study (54.4% were male). HIV infection was found in 147 patients (72.1%) with 38.1% ( n = 56) of them on regular follow-up. The most common clinical signs were fever (84.8%), headache (68.6%), meningeal syndrome (38.7%), and seizures (36.3%). Cerebral toxoplasmosis (24.5%), cryptococcal meningitis (21.1%), and acute bacterial meningitis (8.3%) were leading aetiologies. Of the 143 CSF samples, 70.6% ( n = 101) were sterile. The in-hospital mortality rate was 23.5% with CNS infection of unknown cause (22.1%) be independently associated to this [OR = 2.24; 95% CI 1.04–4.80, p = 0.039]. Conclusion Clinical presentations of CNS infections are same with classical data. HIV-related opportunistic infections are the main aetiologies. About one over four patients with CNS died. Two thirds of CSF are sterile using basic laboratory assessment giving a need to identify simple tests to increase sensibility and specificity of diagnostic tools in our setting.
Background: Campylobacter spp. are one of the most frequent causes of diarrhoeal disease in humans throughout the world. This study aimed at determining the prevalence and the genotypic distribution of Campylobacter spp. and their association with diarrhoea and child growth in children of less than the age of two in the Limpopo Province of South Africa. Methods: A total of 4280 diarrheal and non-diarrheal stool samples were collected on a monthly basis from children recruited at birth and followed up to 24 months. All stool samples were screened for the presence Campylobacter antigen using ELISA technique after which CAH 16S primer was used on the positive samples to confirm the presence of Campylobacter. Subsequently, the PCR positive samples were further characterised using species specific primers for Campylobacter jejuni and Campylobacter coli. Results: Campylobacter antigen was detected in 564/4280 (13.2%). Campylobacter was more commonly found in diarrheal stools (20.4%) compared to non-diarrheal stools (12.4%) with a statistically significant difference (χ2 = 7.345; p = 0.006). Throughout the year there were two main peaks of Campylobacter infection one in December- January and the second peak in June. The prevalence of Campylobacter increased with the age of the children up to 11 months after which the prevalence decreased. Out of 564 positive ELISA samples, 257 (45.6%) were confirmed to have 16S rRNA gene for Campylobacter spp. Furthermore, C. jejuni was found to be more prevalent (232/257) than C. coli (25/257) with a prevalence of 90.3% and 9.7%, respectively. Both C. jejuni and C. coli were significantly associated with diarrhea with statistical values of (χ2 = 22.224; p < 0.001) and (χ2 = 81.682; p < 0.001) respectively. Sequences generated from the analysis of hip gene confirmed the PCR positives samples were C. jejuni positive. Conclusions: This study has delineated a high prevalence of Campylobacter spp. in the study cohort. Moreover, C. jejuni was found to be more prevalent than C. coli both of which were associated with diarrhea. These findings are of clinical and epidemiological significance.
The cartography of lineaments across a territory can be optimized using geophysical potential field data. In this study, land gravity and EMAG2 (Earth Magnetic Anomaly Grid) data were simultaneously used to identify and characterize the major lineaments that spread across Cameroon. The data were filtered using a multi-scale approach including horizontal and vertical gradient analyses. The Euler Deconvolution method was later applied to the filtered data to estimate the extension and depth of the identified lineaments. Results show that the main lineaments across Cameroon are laterally extended with a dominant N45°E orientation. Some of these lineaments correlated well with the geographical location of some known major tectonic structures found across the country. The depth of these lineaments varies between 1 and 35 km. Some of the identified faults are still active as their location correlated with the location of some recent earthquakes that occurred in Cameroon. This work, therefore, highlights some hidden tectonic features which knowledge generally precedes exploration for subsurface resources. Graphical Abstract
Objectives To bring out the diagnostic attitude of hearing professionals in Cameroon towards congenital hearing impairment (CHI), assess availability of tests, neonatal screening, and create a national map of availability of treatment opportunities. Methods We conducted a cross-sectional online-based survey from June to December 2021, concerning ear–nose–throat (ENT) specialists, hearing care professionals, speech therapists and ENT nurses. A Google Forms online questionnaire was used to collect data, filled by eligible professionals involved in hearing care in Cameroon. Results A total of 93 professionals working in 31 different health facilities participated. A cumulative percentage of 79.9% of ENTs were found in just two out of 10 regions. Specialists sought by ENTs for assessment of patients with CHI included neurologists/neuro-pediatricians (96.8%), pediatricians (47.6%), other ENTs (34.9%), and psychologists (3.2%). Investigations requested included auditory-evoked brainstem response (ABR; 87.3%), otoacoustic emissions recording (OAE; 71.4%), and tympanometry (66.7%). There were eight OAE and nine ABR machines in the country. Twenty-five (88.6%) out of 31 facilities with otolaryngologists did not carry out systematic neonatal screening. Reasons included unavailability of equipment (21; 84%), and administrative delays (14; 56%). Sixteen (51.6%) facilities had ENTs with additional training in otologic surgery and 11 (35.5%) were equipped to perform ear surgery. Three centers (9.7%) specialized in hearing aid provision and maintenance services. Three hospitals (9.7%) had performed cochlear implantation. Conclusion Our results show scarcity and overt unevenness in distribution of specialists, equipment and solutions to CHI in Cameroon. A serious negative health care consequence of this shortage is the unavailability of universal newborn hearing screening and implementation programs.
Introduction Chronic diseases are increasing but underdiagnosed in low-income and middle-income countries (LMICs), where injury mortality is already disproportionately high. We estimated prevalence of known chronic disease comorbidities and their association with outcomes among injured patients in Cameroon. Materials and methods Injured patients aged ≥15 y presenting to four Cameroonian hospitals between October 2017 and January 2020 were included. Our explanatory variable was known chronic disease; prevalence was age-standardized. Outcomes were overall in-hospital mortality and admission or transfer from the emergency department (ED). Associations between known chronic disease and outcomes were evaluated using logistic regression adjusted for age, gender, estimated injury severity score (eISS), hospital, and household socioeconomic status. Unadjusted eISS-stratified and age-stratified outcomes were also compared via chi-squared tests. Results Of 7509 injured patients, 370 (4.9%) reported at least one known chronic disease; age-standardized prevalence was 8.4% (95% confidence interval [CI] 7.5%-9.2%). Patients with known chronic disease had higher mortality (4.6% versus 1.5%, adjusted odds ratio [aOR]: 2.61 [95% CI: 1.25-5.47], P = 0.011) and were more likely to be admitted or transferred from the ED (38.7% versus 19.8%, aOR: 1.40 [95% CI: 1.02-1.92], P = 0.038) compared to those without known comorbidities. Crude differences in mortality (11.3% versus 3.3%, P = 0.002) and hospital admission or transfer (63.8% versus 46.6%, P = 0.011) were most notable for patients with eISS 16-24. Conclusions Despite underdiagnosis among Cameroonians, we demonstrated worse injury outcomes among those with known chronic diseases. Integrating chronic disease screening with injury care may help address underdiagnosis in Cameroon. Future work should assess whether chronic disease prevention in LMICs could improve injury outcomes.
Defect-complexes are point defects that significantly influence the geometric, optical, and electrical properties of materials. Defect-complexes are known to improve the electronic and electrical properties of Ge. Deep and shallow defect levels in Ge have been linked to defect-complexes formed by the double self-interstitials and rare earth atoms. Despite this breakthrough, several defect-complexes in Ge are not well understood; hence may pose as a challenge to the optimal performance of Ge based devices. In this study, we present the results of the hybrid density functional theory calculations of substitutional and interstitial defect-complexes (BGeNi, NGeBi, AlGePi, PGeAli, GaGeAsi, AsGeGai, InGeSbi, and SbGeIni) in Ge. Their formation energies, electronic properties, defect-complex stability and induced defect levels in Ge were predicted. While the formation energies of the defect-complexes formed by the P and Al atoms were relatively low and energetically more favourable, those defect-complexes formed by the B and N atoms were the least energetically favourable. Except for the BGeNi, all the defect-complexes significantly bound with energies lower than their formation energies. The NGeBi and PGeAli essential donor levels were in the band gap of Ge. A shallow double acceptor defect level was found to be associated with the AlGePi, while the InGeSbi induced a shallow double donor defect level. The electrical inactive defect-complexes were the BGeNi, GaGeAsi, AsGeGai and SbGeIni. The results of this report are important, as they provide theoretical insight of the prediction of the n/p-type substitutional and interstitial defect-complexes in Ge.
A summary of the research undertaken on poly-aluminum sulfate is performed revealing several disagreements on important thermal properties of the material. Nevertheless, the energy density reported highlights that the material is promising for thermochemical heat storage (THS). A thorough thermal analysis (TA) of (Al2(SO4)3·xH2O) is conducted using TA devices and the ICTAC kinetics committee recommendations, to identify its thermal properties, its most stable form (Al2(SO4)3·18H2O, and the conditions of its use for low-temperature THS (80 °C and 125 °C under atmospheric pressure. The material decomposes in four endothermic stages as shown in the thermal curves and illustrated by possible reaction formulas, three of which are dehydrations followed by a final decomposition. The non-isothermal kinetics of the dehydration for PAS has been determined by the methods of Coats-Redfern (CR) and Achar-Brindley-Sharp (ABS) with 19 different reaction models. It is found that most reaction models exhibit a linear trend. The Janders reaction model is appropriate for the first dehydration with an activation energy of ca. 33.248 kJ/mol by CR and 30.759 kJ/mol by ABS, respectively. Both the power law and the Avrami-Erofeev model can be used for the second stage with an activation energy of ca. 235 kJ/mol. The overall kinetics modeling for aluminum sulfate hydrate is successful for PAS implying the substitution of aluminum sulfate with PAS in applications.
The global increasing trend in total greenhouse gas emissions in recent decades has triggered the need for climate-related development financing. This study analyzes the effects of climate-related development mitigation finance and renewable energy consumption on greenhouse gas emissions in the Congo Basin. Using panel data from 2002 to 2020, panel regression estimates empirically reveal (1) a minimal significant increase in greenhouse gas emissions with respect to an increase in climate-related development mitigation finance (2) An increase in climate-related mitigation finance significantly promotes the consumption of renewable energy (3) An increase in renewable energy consumption reduces greenhouse gas emissions (4) An increase in renewable energy consumption reduces the effect of climate-related mitigation finance on greenhouse emissions. This study suggest the continuous flow of climate-related development mitigation finance from donor countries and bodies to developing countries on a more regular basis and the putting in place of a mechanism that tracks climate funds to ensure that they are effectively used in generating renewable energies such as solar, hydroelectric, biomass, wind and geothermal energies.
Africa, that was known as the cradle of civilization, has over the years been perceived and represented by the western world as a continent plagued with poverty, hunger and starvation, backwardness, civil wars, diseases, corruption and aid-dependency. Western media are fraught with images that lend credence to this. Africans themselves, unfortunately, have helped to propagate this negative image, especially when seeking foreign aid or loans. There is also a high rate of emigration to Europe, North America and recently Asia, via dangerous routes, of young Africans who are supposed to be the pillars of the continent. All these only go to accentuate this prejudice and inform the world that Africa is really not worth living in and that nothing good can come out of her. This chapter seeks to establish the fact that there is a lot which Africa can offer her citizens and the rest of the world.KeywordsEcological heritageCultural heritageCultural performanceSustainabilitySoft power
Abstract Background Malaria remains endemic in Cameroon, with heterogeneous transmission related to eco-climatic variations, vector diversity and spatial distribution. The intensification of malaria prevention and control through the free distribution of insecticide-treated nets in recent years may have altered the composition, geographic distribution and natural infection rate of Anopheles species, with implications for malaria transmission dynamics. The present study seeks to assess the vectorial diversity, dynamics and infectivity across different seasons and altitudes in relationship to parasite prevalence around the slopes of Mount Cameroon, southwestern region. Method Mosquitoes were sampled (indoors and outdoors) in 11 eco-epidemiological settings at low (18–197 m), intermediate (371–584 m) and high (740–1067 m) altitude by nightly human landing catches. The mosquitoes were identified morphologically and Anopheles gambiae sibling species identified by PCR. Parity status was ascertained by examining the ovaries and the entomological inoculation rates (EIR) determined by Plasmodium falciparum circumsporozoite antigen ELISA of the head-thorax. The prevalence of Plasmodium infection across target communities was assessed using rapid diagnostic tests. Results A total of 7327 (18.0 mosquitoes/trap/night) mosquitoes were trapped, mainly during the rainy season (5678, 77.5%) and at low altitude (3669, 50.1%). Anopheles spp. (5079, 69.3%) was the most abundant genera and An. gambiae complex (2691, 36.7%) the major vector, varying with altitude (χ 2 = 183.87, df = 8, P
In recent years, there has been ample evidence illustrating the effect of microbiota on gut immunity, homeostasis, and disease. Most of these studies have engaged more efforts in understanding the role of the bacteriome in gut mucosal immunity and disease. However, studies on the virome and its influence on gut mucosal immunity and pathology are still at infancy owing to limited metagenomic tools. Nonetheless, the existing studies on the virome have largely been focused on the bacteriophages as these represent the main component of the virome with little information on endogenous retroviruses (ERVs) and eukaryotic viruses. In this review, we describe the gut virome, and its role in gut mucosal response and disease progression. We also explore the crosstalk between the virome and other microorganisms in the gut mucosa and elaborate on how these interactions shape the gut mucosal immunity going from bacteriophages through ERVs to eukaryotic viruses. Finally, we elucidate the potential contribution of this crosstalk in the pathogenesis of inflammatory bowel diseases and colon cancer.
Rytigynia senegalensis (Rubiaceae) is a plant used in African medicine for the treatment of diabetes. The aim of this study was to evaluate the in vitro antioxidant, enzyme inhibitory, and hypoglycemic effects of Rytigynia senegalensis extract (RSE). The contents of phenols, tannins, and flavonoids were determined by phytochemical screening. 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenylpicrylhydrazyl (DPPH) were determined to evaluate the free radical scavenging capacity of the RSE. The inhibitory activity of α-amylase and α-glucosidase was evaluated in vitro using the α-amylase and α-glucosidase inhibition methods and in vivo using the sucrose and starch tolerance tests. The glucose tolerance test was performed on normal rats using doses of 50, 100, and 200 mg/kg of RSE. RSE contains total phenols (36.35 mg GAE/g of extract), flavonoids (11.91 mg QE/g of extract), and tannins (13.01 mg CE/g of extract). RSE exhibits significant radical scavenging activity on DPPH and ABTS radicals with an IC50 of 17.51 and 21.89 μg/mL, respectively. RSE showed an inhibitory effect on the activity of α-amylase and α-glucosidase with an IC50 of 308.93 and 354.13 μg/mL, respectively. RSE (100 and 200 mg/kg) caused a significant decrease in area under the curve and postprandial glycemia at 60, 90, and 120 min following the administration of starch or sucrose. Regarding the glucose tolerance test, RSE (100 and 200 mg/kg) significantly reduced postprandial hyperglycemia from the 90th min posttreatment. RSE lowered postprandial hyperglycemia and has antioxidant properties. These effects would be due to the presence of bioactive compounds in the RSE.
Lymphatic filariasis and onchocerciasis are major neglected tropical diseases affecting over 90 million people worldwide with painful and profoundly disfiguring pathologies (such as lymphoedema or blindness). Type 2 inflammation is a hallmark of filarial nematode tissue infection and is implicated both in eosinophil dependent immunity and lymphatic or ocular immunopathologies. Type-2 innate lymphoid cells (ILC2) are known to play an important role in the initiation of type 2 inflammation in helminth infection. We therefore tracked comparative IL-12Rb2 + ILC1, ST2 + ILC2 and NKp46 + natural killer (NK) innate lymphoid cell population expansions during Brugia malayi experimental peritoneal filarial infections using either immunocompetent or immunodeficient mice. In immunocompetent BALB/c animals, NKp46 + NK cells rapidly expanded representing over 90% of the ILC population in the first week of infection, whereas, surprisingly, ST2 + ILC2 failed to expand. NKp46 + NK cell expansions were confirmed in RAG2 deficient mice lacking adaptive immunity. Ablation of the NKp46 + NK cell compartment in RAG2 common gamma chain (gc) mice led to increased susceptibility to chronic adult B. malayi infection. This data was recapitulated using an Onchocerca ochengi male worm peritoneal implant model. When NKp46 + NK cells were depleted in RAG2 deficient mice using anti-NKp46 or asialo GM1 antibody injections over the first five weeks of B. malayi infection, susceptibility to adult B. malayi infection was significantly increased by 2-3 fold with concomitant impairment in eosinophil or neutrophil recruitments. Finally, we demonstrate that in RAG2 deficient mice, drug clearance of a primary adult B. malayi infection followed by challenge infection leads to resistance against early larval B. malayi establishment. This innate resistance is associated with bolstered NK and Frontiers in Immunology (2022) NKp46 + natural killer cells develop an activated/ memory-like phenotype and contribute to innate immunity against experimental filarial infection. Front. Immunol. 13:969340.
Background: Injury deaths in sub-Saharan Africa are among the world's highest, but hospital data rarely have sufficient granularity to direct quality improvement. We analyzed clinical care patterns among trauma patients who died in a prospective, multi-center sub-Saharan cohort to pinpoint trauma quality improvement intervention targets. Methods: In-hospital trauma deaths in four Cameroonian hospitals between 2017 and 2019 were included. Trauma registry data on patient demographics, injury characteristics, and clinical care were analyzed to identify opportunities for systems improvements. Results: Among 9423 trauma patients, there were 236 deaths. Overall, 83% of patients who died in the emergency department were living on arrival (LOA). Among 183 LOA patients, 30% presented with normal vital signs, but 11% had no vital signs taken, often due to lack of equipment (43%). Of LOA patients presenting with GCS < 9 (56%), few received neurosurgery consults (15%), C-collar placement (9%) or intubation (1%). The most common reason for lack of c-collar placement was failure to recognize that it was indicated (66%). Tracheal deviation, unequal breath sounds, or paradoxical chest movement were present in 63% of LOA patients, but only 2 patients had chest tubes placed. Hypotension or active bleeding was present in 80% of LOA patients; while crystalloid bolus was given to 96% of these patients, few received transfusion (8%), tourniquet placement for extremity injury (6%) or an operation (4%). Conclusion: Primary survey interventions are underperformed in trauma non-survivors in Cameroon. Protocolizing early treatment for head injury, hemorrhagic shock, and chest wall trauma could reduce trauma mortality. Level of evidence: Level III, prognostic (prospective) study.
Background. Menopause is a normal event characterized by a drop in estrogen’s production, leading to numerous symptoms. To face these later, women rely on hormone replacement therapy (HRT), which alleviates numerous menopausal symptoms. Unfortunately, long-term exposure to estrogens is associated with an increase in endometrial and breast cancers. This study dealt with the evaluation of in vitro and in vivo antiproliferative effects of Solanum gilo Raddi, a plant used in folk medicine to treat tumors in Cameroon. Materials and Methods. The in vitro antiproliferative effect of S. gilo fruit extract was investigated through the well-characterized MTT assay in one normal and three cancerous breast cells. For the in vivo study, one normal group (NOR) of rats received distilled water (vehicle), and five other groups (n = 6) were treated either with tamoxifen (3.3 mg/kg BW) as standard or with the vehicle (negative control) or S. gilo fruit hydroethanolic extract (125, 250, and 500 mg/kg BW). The treatments were administered concomitantly with the E2V to induce breast hyperplasia for 16 weeks, and the endpoints were the histopathology of the mammary glands and some biochemical parameters. Results. The S. gilo extract significantly inhibited human (MCF-7 and MDA-MB-231) and rodent (4T1) breast carcinoma cell growth. Rats exposed only to E2V presented atypical mammary hyperplasia compared to the normal parenchyma observed in normal rats. While rats treated with S. gilo extract at the dose of 125 mg/kg BW showed a microarchitecture of mammary glands with moderate hyperplasia, the higher doses (250 and 500 mg/kg) inhibited mammary gland hyperplasia compared to the E2V group. Conclusion. S. gilo fruit extract has antiproliferative constituents that could help to fight against estrogen-dependent breast cancer, thanks to their ability to scavenge free radicals, as exhibited in this study.
Background Home injuries are an important cause of morbidity and mortality in high-income countries. In Sub-Saharan Africa, including Cameroon, many people live in unplanned settlements with poorly constructed houses, predisposing them to home injuries. However, little is known about the epidemiology and care-seeking behaviors of the domestically injured. In this study, our objective was to determine the epidemiology and care-seeking behaviors of home injuries in the Southwest Region of Cameroon. Methods A sub-analyses of a larger descriptive cross-sectional community-based study on injury epidemiology in the preceding 12 months was conducted. Sampling was done using three-stage cluster sampling technique. Differences between groups were evaluated using Chi-squared and Adjusted Wald tests. Results Of 8065 participants, 157 suffered home injuries giving an incidence of 19.6 (16.8–23.0 95% CI) cases per 1000-person years. Home injuries comprised 31.2% of all 503 injuries and affected more females (60.8%) and younger individuals (mean age (SE) 25.1 years (2.0)) than non-home injuries. The most common activity and mechanism of home injury was leisure/play (51%) and falls (37.9%) respectively. Amongst those with home injuries, 37.6% did not seek care from any care provider (versus 25.0% of non-home injuries, p = 0.004) and were more likely to seek treatment within the family or at home (p = 0.008) or at church (p = 0.010). Those with home injuries experienced a median of 14 disability days and 22.9% of families faced difficulties affording basic expenses (p = 0.001). Conclusion Home injuries comprise about a third of the Southwest Region of Cameroon’s burden of injury and likely have a profound socioeconomic impact. Though these injuries cause severe disabilities, a large proportion of victims do not seek care from providers. Prevention efforts should address the design of homes and victims of home injury should be encouraged to utilize formal care services.
We investigate the dynamics of a pair of coupled non oscillatory Rayleigh-Duffing oscillators (RDOs here after). The RDO serves as a model for a class of nonlinear oscillators including microwave Gunn oscillators [Guin et al., Comm. in Nonlinear Sci. Numerical Simulat, 2017]. Here, the coupling between the two oscillators is obtained by superimposing to each one’s amplitude a perturbation proportional to the other one. We demonstrate that the coupling induces more equilibrium points and results in extremely complex nonlinear behaviors including multistability (up to six coexisting attractors), multiple Hopf bifurcations, multi-scroll chaos, and coexisting bifurcation trees. These phenomena are studied in detail by utilizing one-parametric bifurcation plots, bi-parametric Lyapunov exponent diagrams, phase space trajectory plots, and basins of attraction as well. Experimental results captured from an Arduino microcontroller-based realization of the coupled RDOs are included to support the observations made through numerical analysis. We would like to point out that the coupling scheme followed in this work may stimulate the research on multiscroll chaos generation based on coupled nonlinear oscillators.
Background The SARS-CoV-2 pandemic is a global threat affecting 210 countries, with 2,177,469 confirmed cases and 6.67% case fatality rate as of April 16, 2020. In Africa, 17,243 cases have been confirmed, but many remain undiagnosed due to limited laboratory-capacity, suboptimal performance of used molecular-assays (~30% false negative, Yu et al . and Zhao et al ., 2020) and limited WHO-recommended rapid-tests. Objectives We aim to implement measures to minimize risks for COVID-19 in Cameroon, putting together multidisciplinary highly-experienced virologists, immunologists, bioinformaticians and clinicians, to achieve the following objectives: (a) to integrate/improve available-infrastructure, methodologies, and expertise on COVID-19. For this purpose, we will create a platform enabling researchers/clinicians to better integrate and translate evidence into the COVID-19 clinical-practice; (b) to enhance capacities in Cameroon for screening/detecting individuals with high-risks of COVID-19, by setting-up effective core-facilities on-site; (c) to validate point-of-care SARS-CoV-2 molecular assays allowing same-day result delivery, thus permitting timely diagnosis, treatment, and retention in care of COVID-19 patients; (d) to implement SARS-CoV-2 diagnosis with innovative/highly sensitive ddPCR-based assays and viral genetic characterization; (e) to validate serological assays to identify COVID-19-exposed persons and follow-up of convalescents. Methods This is a prospective, observational study conducted among COVID-19 suspects/contacts during 24 months in Cameroon. Following consecutive sampling of 1,536 individuals, oro/nasopharyngeal swabs and sera will be collected. Well characterised biorepositories will be established locally; molecular testing will be performed on conventional real-time qPCR, point-of-care GeneXpert, antigen-tests and digital droplet PCR (ddPCR); SARS-CoV2 amplicons will be sequenced; serological testing will be performed using ELISA, and antibody-based kits. Sensitivity, specificity, positive- and negative-predictive values will be evaluated. Expected outcomes These efforts will contribute in creating the technical and clinical environment to facilitate earlier detection of Sars-CoV-2 in Africa in general and in Cameroon in particular. Specifically, the goals will be: (a) to implement technology transfer for capacity-building on conventional and point-of-care molecular assays, achieving a desirable performance for clinical diagnosis of SARS-CoV2; (b) to integrate/improve the available infrastructure, methodologies, and expertise on Sars-CoV2 detection; (c) to improve the turn-around-time for diagnosing COVID-19 infection with obvious advantage for patients/clinical management thanks to low-cost assays, thus permitting timely treatment and retention in care; (d) to assess the epidemiology of COVID-19 and circulating-variants in Cameroon as compared to strains found in other countries.
The design of structural elements, the design of connections and supports, and damage have a significant influence on the technical characteristics of wood construction projects. An innovative experimental study was carried on locally obtained glulam beams. This study aimed to evaluate the load-bearing capacity of a finger-jointed Terminalia Superba (fraké) lamellae during routine use of an adhesive in the local area and to improve the connections in glulam structures. The achievement of this objective will allow to determine the influence of the technical characteristics of finger-jointing on the mechanical resistance, to maximize the mechanical resistance of the reconstituted beams, and eventually to minimize the losses due to sawing. All this will have a considerable impact on the technical and economic aspects of a wood construction project. The physical aspect of the species was studied and properties found. The influence of variation in density, the bonding surface, and joint efficiency on the bending strength (MOR) of Terminalia Superba (fraké) was studied. Mechanical properties were found and related to the optimum joint angle α, and the breaking point reads 0.20 mm. For the angular range of [0°–30°], adhesive failures are witnessed, and beyond this range, the failures are mixed. The 45° finger-jointing angle appeared to be better in the axial traction mode of rupture.
In this article, we propose the Holling type-II predator-prey model involving cannibalism and gestation delay in predators. We study the existence of all possible equilibrium points of the proposed model. We give the condition for the local stability and Hopf bifurcation analysis for the nondelayed model. Next, we also establish the local stability and Hopf bifurcation analysis for the corresponding delayed model. Finally, we discuss how cannibalism and delay play an important role in stabilizing and destabilizing the proposed system both theoretically and numerically.
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1,476 members
Thomas obinchemti Egbe
  • Department of Gynaecology and Obstetrics
Manfo T faustin P
  • Department of Biochemistry and Molecular Biology (BMB)
Elroy Patrick Weledji
  • Department of Surgery
Kwenti Emmanuel Tebit
  • Department of Medical Laboratory Science
George Chuyong
  • Department of Botany and Plant Physiology
Molyko, Buea, South West Region, Cameroon
Head of institution
Prof. Ngomo Horace Manga