Prevalence of HIV, HBV and Chlamydia infections in Cameroonian University context: case of the University of Dschang, in the Western Region

Introduction: In sub-Saharan Africa HIV infection remains largely epidemic, whereas HBV infection is highly endemic (>8%). In Cameroon, HIV prevalence is 4.3%. Concerning HBV and chlamydia infections, their prevalence are both ≥10%. Young adults, including university students, are the population groups mostly affected. Epidemiological data on these infections, among university students could be helpful to implement specific prevention strategies. Methods: A descriptive study was performed in May 2013 among 624 students from the University of Dschang, Cameroon. Participants were screened for HIV, HBV and Chlamydia infections. Data was collected by a standard questionnaire and analyzed by Epi Info. Results: Average age of participants was 23.3 years (σ = 3.2) with female predominance (58.7%). Prevalence of HIV, HBV and Chlamydia infection was 1.1% (7/624), 2.8% (5/176) and 2.0% (2/100) respectively. 83.2% of participants were sexually active. Concerning sexual risk behaviors, participants reported having multi partners (14.8%), using condom occasionally (58.6%) or never (5.0%). 100%, 62.6% and 52.2% reported to be aware on HIV, HBV and Chlamydia infections respectively. In addition, only 5.5% and 21.3% of the participants were aware of their HBV and Chlamydia status respectively, versus 64.4% for HIV. The excessive cost of HBV and Chlamydia tests has been identified as the major barrier to testing (87.6%). Conclusion: Among college Cameroonian students the prevalence of HIV, HBV and Chlamydia infections seems to be relatively low if compared to general population. However, having multiple sexual partners in addition to non-systematic use of condoms during sexual intercourse represents risk behaviors among students. Awareness campaigns and screening facilitation on HBV and chlamydia infections need to be strengthened

Characterising The Atmospheric Dynamics Of HD209458b-like Hot Jupiters Using AI Driven Image Recognition/Categorisation

In-order to understand the results of recent observations of exoplanets, models have become increasingly complex. Unfortunately this increases both the computational cost and output size of said models. We intend to explore if AI-image-recognition can alleviate this burden. We used DYNAMICO to run a series of HD209458-like models with different orbital-radii. Training data for a number of features of interest was selected from the initial outputs of these models. This was used to train a pair of multi-categorisation convolutional-neural-networks (CNN), which we applied to our outer-atmosphere-equilibrated models. The features detected by our CNNs revealed that our models fall into two regimes: models with a shorter orbital-radii exhibit significant global mixing which shapes the entire atmospheres dynamics. Whereas, models with longer orbital-radii exhibit negligible mixing except at mid-pressures. Here, the initial non-detection of any trained features revealed a surprise: a night-side hot-spot. Analysis suggests that this occurs when rotational influence is sufficiently weak that divergent flows from the day-side to the night-side dominate over rotational-driven transport, such as the equatorial jet. We suggest that image-classification may play an important role in future, computational, atmospheric studies. However special care must be paid to the data feed into the model, from the colourmap, to training the CNN on features with enough breadth and complexity that the CNN can learn to detect them. However, by using preliminary-studies and prior-models, this should be more than achievable for future exascale calculations, allowing for a significant reduction in future workloads and computational resources.Comment: Accepted for publication in Ap

Hepato-protective, antioxidant activities and acute toxicity of a stem bark extract of Erythrina senegalensis DC.

This study aimed at evaluating the in vitro antioxidant and hepatoprotective activities of different stem bark extracts of Erythrina senegalensis prepared with ethanol, and the in vivo hepatoprotective activity and acute toxicity of the best extract. The 2, 4-diphenyl-1-picryl-hydrazil (DPPH) and microsomal lipid peroxidation (MLP) models, and the rat liver slices system were respectively used for the in vitro study. The Methylene chloride/methanol (1:1 v/v) (Emc) and 40% ethanolic (E40) extracts were more efficient in inhibiting MLP and in scavenging DPPH radical. However, E40 was most effective with regards to lactate dehydrogenase (LDH) leakage inhibition from rat liver slices intoxicated with carbon tetrachloride (CCl4). The in vivo hepatoprotective activity was evaluated against CCl4-induced hepatotoxicity in rats. The E40 extract (100 mg/Kg) significantly reduced the increase in ALT, AST and lipid peroxidation in liver homogenate, showing that the extract is as protective as silymarin at the same dose. Acute toxicity was evaluated in mice and E40 did not produce any behavioural changes or mortality even at an oral dose of 16 g/kg. The extract was found to contain antioxidant classes of compounds (flavonoids and polyphenols). In conclusion, the E40 extract of E. senegalensis could be an important source of hepatoprotective compounds.Key words: Erythrina senegalensis, stem bark extract, antioxidant, hepatoprotective, carbon tetrachloride

HIV and HBV infection in Cameroonian university context: Case of the University of Dschang

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Characterising co-infections with Plasmodium spp., Mansonella perstans or Loa loa in asymptomatic children, adults and elderly people living on Bioko Island using nucleic acids extracted from malaria rapid diagnostic tests

BACKGROUND: Regular and comprehensive epidemiological surveys of the filarial nematodes Mansonella perstans and Loa loa in children, adolescents and adults living across Bioko Island, Equatorial Guinea are lacking. We aimed to demonstrate that blood retained on malaria rapid diagnostic tests, commonly deployed for malaria surveys, could be used as a source of nucleic acids for molecular based detection of M. perstans and L. loa. We wanted to determine the positivity rate and distribution of filarial nematodes across different age groups and geographical areas as well as to understand level of co-infections with malaria in an asymptomatic population. METHODOLOGY: M. perstans, L. loa and Plasmodium spp. parasites were monitored by qPCR in a cross-sectional study using DNA extracted from a subset malaria rapid diagnostic tests (mRDTs) collected during the annual malaria indicator survey conducted on Bioko Island in 2018. PRINCIPAL FINDINGS: We identified DNA specific for the two filarial nematodes investigated among 8.2% (263) of the 3214 RDTs screened. Positivity rates of M. perstans and L. loa were 6.6% and 1.5%, respectively. M. perstans infection were more prominent in male (10.5%) compared to female (3.9%) survey participants. M. perstans parasite density and positivity rate was higher among older people and the population living in rural areas. The socio-economic status of participants strongly influenced the infection rate with people belonging to the lowest socio-economic quintile more than 3 and 5 times more likely to be L. loa and M. perstans infected, respectively. No increased risk of being co-infected with Plasmodium spp. parasites was observed among the different age groups. CONCLUSIONS/SIGNIFICANCE: We found otherwise asymptomatic individuals were infected with M. perstans and L. loa. Our study demonstrates that employing mRDTs probed with blood for malaria testing represents a promising, future tool to preserve and ship NAs at room temperature to laboratories for molecular, high-throughput diagnosis and genotyping of blood-dwelling nematode filarial infections. Using this approach, asymptomatic populations can be reached and surveyed for infectious diseases beyond malaria

Raman structural study of random olefin copolymers

In this work we present Raman study of random copolymers of ethylene and propylene with a number of α-olefins, and investigation of the relationships between the spectral characteristics of the Raman lines and the copolymer structural properties. For both the copolymers we observed rapid decrease in the crystallinity and conformational order as the content of the incorporated monomer increases

Increased Biting Rate of Insecticide-Resistant Culex Mosquitoes and Community Adherence to IRS for Malaria Control in Urban Malabo, Bioko Island, Equatorial Guinea.

Sustaining high levels of indoor residual spraying (IRS) coverage (≥85%) for community protection against malaria remains a challenge for IRS campaigns. We examined biting rates and insecticide resistance in Culex species and Anopheles gambiae s.l., and their potential effect on community adherence to IRS. The average IRS coverage in urban Malabo between 2015 and 2017 remained at 80%. Culex biting rate increased 6.0-fold (P < 0.001) between 2014 and 2017, reaching 8.08 bites per person per night, whereas that of An. gambiae s.l. remained steady at around 0.68. Although An. gambiae s.l. was susceptible to carbamates and organophosphates insecticides, Culex spp. were phenotypically resistant to all four main classes of WHO-recommended IRS insecticides. Similarly, the residual activity of the organophosphate insecticide used since 2017, ACTELLIC 300CS, was 8 mo for An. gambiae s.l., but was almost absent against Culex for 2 mo post-spray. A survey conducted in 2018 within urban Malabo indicated that 77.0% of respondents related IRS as means of protection against mosquito bites, but only 3.2% knew that only Anopheles mosquitoes transmit malaria. Therefore, the increasing biting rates of culicines in urban Malabo, and their resistance to all IRS insecticides, is raising concern that a growing number of people may refuse to participate in IRS as result of its perceived failure in controlling mosquitoes. Although this is not yet the case on Bioko Island, communication strategies need refining to sensitize communities about the effectiveness of IRS in controlling malaria vectors in the midst of insecticide resistance in nonmalaria vector mosquitoes

Utilisation et conservation des ressources en sol et en eau (Nord Cameroun) : rapport final

Après avoir étudié les principaux facteurs régionaux du milieu naturel, une partie de l'étude est consacrée à la caractérisation et à la cartographie des systèmes écologiques de la région de Mouda. Une troisième partie est axée sur les problèmes de fonctionnement des espèces ligneuses et herbacées et fait appel à la connaissance du régime hydrique des sols et à l'organisation des couvertures pédologiques. Une dernière étude, celle du ruissellement et de l'érosion peut être considérée comme la ligne principale du projet