Begomovirus disease complex: emerging threat to vegetable production systems of West and Central Africa

Vegetables play a major role in the livelihoods of the rural poor in Africa. Among major constraints to vegetable production worldwide are diseases caused by a group of viruses belonging to the genus Begomovirus, family Geminiviridae. Begomoviruses are plant-infecting viruses, which are transmitted by the whitefly vector Bemisia tabaci and have been known to cause extreme yield reduction in a number of economically important vegetables around the world. Several begomoviruses have been detected infecting vegetable crops in West and Central Africa (WCA). Small single stranded circular molecules, alphasatellites and betasatellites, which are about half the size of their helper begomovirus genome, have also been detected in plants infected by begomoviruses. In WCA, B. tabaci has been associated with suspected begomovirus infections in many vegetable crops and weed species. Sequencing of viral genomes from crops such as okra resulted in the identification of two previously known begomovirus species (Cotton leaf curl Gezira virus and Okra yellow crinkle virus) as well as a new recombinant begomovirus species (Okra leaf curl Cameroon virus), a betasatellite (Cotton leaf curl Gezira betasatellite) and new alphasatellites. Tomato and pepper plants with leaf curling were shown to contain isolates of new begomoviruses, collectively referred to as West African tomato-infecting begomoviruses (WATIBs), new alphasatellites and betasatellites. To study the potential of weeds serving as begomovirus reservoirs, begomoviruses and satellites in the weed Ageratum conyzoides were characterized. Sequence analyses showed that they were infected by isolates of a new begomovirus (Ageratum leaf curl Cameroon virus) that belong to the WATIBs group, a new betasatellite (Ageratum leaf curl Cameroon betasatellite), an alphasatellite and two types of defective recombinants between a begomovirus and an alphasatellite. Putative recombinations were detected in begomovirus genomes for all four plant species studied, indicating that recombination is an important mechanism for their evolution. A close relationship between the begomoviruses infecting pepper and tomato and A. conyzoides and the detection of the same alphasatellite in them support the idea that weeds are important reservoirs for begomoviruses and their satellites. With this high diversity, recombination potential and transmission by B. tabaci, begomoviruses and ssDNA satellites pose a serious threat to crop production in West and Central Africa

Upgrading n-Heptane via Catalytic Hydroisomerisation

An atmospheric pressure upgrading of n-heptane was carried out in a temperature range of 300 to 450oC over an in situ developed molybdenum carbide phase supported over sulphated zirconia. Although a decreased in surface area with increased in pore volume were observed after carburization, the physicochemical data showed no noticeable alteration to the zirconia structure or the sulphate species. The catalyst formed a good system with high selectivity to iso-heptanes under either low temperature or high space velocity. It therefore has promising features that could offer mitigation to some of the challenges faced by the petroleum refineries with noble metals promoted zeolites. Keywords: n-heptane, hydroisomerisation, carbide catalyst, stability, sulphated zirconia

Production of Liquefied Petroleum Gas (LPG) Range Alkanes from n-Octane via Catalytic Hydroconversion

The production of light range alkanes with potentials as LPGs was carried out at 1 atm pressure over a range of reaction temperatures using both in situ and ex situ prepared molybdenum carbide supported sulphated zirconia catalysts. The in situ synthesized material formed the best system in terms of stability, conversion and selectivity to desired reaction products, as well as resistance to thermal treatment. This suggests its prospects as industrial material. Mechanistically, the reaction was believed to involved the participation of both the carbide and the sulphated zirconia surfaces via hydrogenolysis and hydrocracking, respectively. Reactions over the carbide formed mainly methane whereas propane and butanes could significantly be obtained over the sulphated zirconia. Keywords: n-octane, hydroconversion, light gases, fuel, prospect

Characterization of intestinal microbiota in celiac children

Celiac disease (CD) is enteropathy autoimmune induced by the ingestion of gluten in genetically predisposed subjects. The ingestion of gluten is responsible for the symptoms of CD, and a disturber of the intestinal microbiota. In this study, 13 Samples of intestinal biopsy, 15 fecal samples from celiac children, and 10 from controls children respectively were collected and analyzed by conventional culture technique to characterize the microbial profile intestinal of celiac children. There was 24 celiac children (8 boys), Mean age at diagnosis was 9.52 years, all have clinical manifestations, positive anti-transglutaminase antibodies and mucosal lesions suggestive of CD (Marsh Classification).We found a difference in intestinal microbiota, between celiac and controls children for example  the  Enterobacteria,  Clostridium sp and Staphylococcus sp were remarkably higher in biopsy and fecal samples of celiac children than in controls. Inversely the Enterococcus sp, Lactobacillus sp and Clostridium sp were slightly lower in celiac children. Our results indicate an imbalance in intestinal microbiota for celiac children as reduction in the numbers of Lactobacillus sp, Enterococcus sp and increases in the numbers of Enterobacteria, Staphylococcus sp and Clostridium sp.Keywords: Celiac disease, Intestinal Microbiota, Anti-transglutaminase, Lacobacillus sp

Epidemio-Clinical Factors Associated with Caesarean Section in Two Referral Hospitals (Public/Faith-Based), Far-North Region, Cameroon

Caesarean section incurs significant cost and poses a hindrance to healthcare. The aim of the study was to determine maternal, foetal outcomes and cost. This was a cross sectional study conducted at the two health facilities. The study covered an eight month period. The rate of caesarean section was 5.69% and 6.22% at the semi-urban and rural hospital. Adolescents were predominant (27.86%) in the semi-urban group. 70% of the mothers in the rural environment were uneducated. Prenatal consultation of four was carried out by 92% of the rural women. Cephalo-pelvic disproportion remained the main indication for surgery. The type of anaesthesia was general (96.72%) and spinal (83.33%). Post-operative complications were dominated by haemorrhage and infection. The mean cost for surgery was 80.000 F in the semi-urban area. At the rural hospital the cost fixed at 19.000 and 32.000 F. The cost of surgery in the two hospitals is cheap compared to other healthcare facilities in the Country.Keywords caesarean section; maternal and perinatal mortality; maternal morbidity; rural; semi-urban; cos

Factors associated to bed net use in Cameroon: a retrospective study in Mfou health district in the Centre Region

Introduction: Insecticide treated net remains a tool of choice for malaria prevention in Cameroon. However, data suggests that its use by thepopulation, especially vulnerable groups remains low. Moreover, there is a paucity of information about factors influencing its use. We sought outto identify factors associated with net use in Mfou health district, prior to distribution of long lasting insecticides treated nets (LLINs) in households.Methods: A two-stage cluster random sampling was conducted in 4 health areas with an average of 13 villages each. A total of 541 householdswere selected and heads interviewed using a structured household questionnaire. Data collected were entered into a database and multivariate logistic regression analyses of the association between net use and explanatory factors were performed using SPSS.Results: Net possession and use were respectively, 59.7 and 42.6%; thus, 2 out of 5 people who spent the previous night in households, slept under a net. Factors associated with net use included: net density.0.5 (OR=8.88, 95% CI: 6.24-12.64), age.5 years (OR=0.37, 95%CI: 0.28-0.47), secondary education (OR=1.41, 95% CI: 1.11-1.80) compared to primary/no education, parent status (OR=3.32, 95% CI: 2.31-4.76), house  construction (OR=1.37, 95% CI: 1.10-1.71) and environment characteristics (OR=1.46, 95% CI: 1.18-1.80).Conclusion: These data suggest that a universal coverage with one LLIN for two people should be achieved in households. Then, malaria health education should be conducted to re-enforce net use among school-aged children and adolescents, as well as older household members. Moreover, management of environment and improvement in houses construction are necessary.Key words: Malaria, factors, insecticides treated nets, health district, Cameroo

Adsorption Kinetics of Pb(II) and Zn(II) Ions unto Carbonized Groundnut Shells and Maize Cobs

Maize cobs and groundnut shell adsorbents from agricultural by-products were carbonized and investigated for adsorption of two selected metals, Lead (Pb II) and Zinc (Zn II) from aqueous solutions of these metals. Kinetic studies of the adsorption processes were investigated employing Elovich and the intraparticle diffussion models. The results showed that, the adsorption capacities of these comparatively cheaper adsorbents and their efficiency for the removal of Pb(II) and Zn(II) ions from aqueous solution present them suitable for use in place of the costly commercial activated carbons

Current practice of epidemiology in Africa: highlights of the 3rd conference of the African epidemiological association and 1st conference of the Cameroon society of epidemiology, Yaoundé, Cameroon, 2014

As the study of disease occurrence and health indicators in human populations, Epidemiology is a dynamic field that evolves with time and geographical context. In order to update African health workers on current epidemiological practices and to draw awareness of early career epidemiologists on concepts and opportunities in the field, the 3rd African Epidemiology Association and the 1st Cameroon Society of Epidemiology Conference was organized in June 2-6, 2014 at the Yaoundé Mont Febe Hotel, in Cameroon. Under the theme«Practice of Epidemiology in Africa: Stakes, Challenges and Perspectives», the conference attracted close to five hundred guest and participants from all continents. The two main programs were the pre-conference course for capacity building of African Early Career epidemiologists, and the conference itself, providing a forum for scientific exchanges on recent epidemiological concepts, encouraging the use of epidemiological methods in studying large disease burden and neglected tropical diseases; and highlighting existing opportunities

COVID-19: Shining the Light on Africa.

COVID-19: Shining the Light on Africa

Antibody responses to the full-length VAR2CSA and its DBL domains in Cameroonian children and teenagers

Additional file 2. IgG levels to VAR2CSA domains in 10–15 year old Cameroonian girls living in Ngali II and Ntouessong villages. IgG levels to VAR2CSA DBL domains and full-length protein (FV2) were measured in 11–15 year old girls residing in Ngali II and Ntouessong villages. DBL1 domain was from 3D7 strain and all the other proteins from FCR3 parasite strain. Median MFI and Inter-Quartile Range (IQR) are plotted