Seroprevalence of Toxoplasmosis and associated risk factors in pregnant women at the Protestant Hospital, Mbouo-Bandjoun, Cameroon

Background: Toxoplasmosis is a common worldwide infection caused by the protozoan Toxoplasma gondii. In Cameroon, several recent studies have reported high seroprevalence of this parasitosis in various hospitals (Douala, Limbe, Njinikom and Yaoundé). The aim of this study was to determine whether this high prevalence of toxoplasmosis might occur in other regions of the country.Methodology: Serological tests by the indirect Enzyme Linked Immunosorbent Assay (ELISA) for IgG and IgM were carried out on 200 pregnant women (36 HIV-positive and 164 HIV-negative) at the Protestant Hospital of Mbouo-Bandjoun in western Cameroon to determine the presence of Toxoplasma gondii infection and to identify the risk factors associated with seropositivity of the subjects.Results: The overall seroprevalence of anti-Toxoplasma antibodies was 45.5%. The prevalence rate was 80.5% in the HIV-positive group (47.2% IgG, 22.2% IgM and 11.1% IgG + IgM) and 37.8% in the HIV-negative group (25.6%, 9.7% and 2.4% respectively). Using a multivariate logistic regression analysis, the secondary level of educational, presence of HIV infection, and frequency of close contacts with cats were significantly associated with the prevalence of IgG and/or IgM antibodies.Conclusion: Compared with previous reports of human toxoplasmosis in Cameroon, the prevalence in our study showed a decrease in the disease occurrence. Further studies are needed to determine whether this decrease is localised to our study or a general phenomenon currently affecting the country.Keywords: Cameroon, IgG, IgM, pregnant women, seroprevalence, Toxoplasma gondi

Synthesis of novel stilbene–coumarin derivatives and antifungal screening of monotes kerstingii-specialized metabolites against fusarium oxysporum

Fusarium is one of the most toxigenic phytopathogens causing diseases and reduced agricultural productivity worldwide. Current chemical fungicides exhibit toxicity against non-target organisms, triggering negative environmental impact, and are a danger to consumers. In order to explore the chemical diversity of plants for potential antifungal applications, crude extract and fractions from Monotes kerstingii were screened for their activity against two multi-resistant Fusarium oxysporum strains: Fo32931 and Fo4287. Antifungal activity was evaluated by the determination of minimum inhibitory concentration (MIC) by broth dilution of fermentative yeasts using kinetic OD600 nm reading by a spectrophotometer. The n-butanol fraction showed the best activity against Fo4287. We screened eleven previously reported natural compounds isolated from different fractions, and a stilbene–coumarin 5-[(1E)-2-(4-hydroxyphenyl)ethenyl]-4,7-dimethoxy-3-methyl-2H-1-benzopyran-2-one (1) was the most active compound against both strains. Compound 1 was employed as a nucleophile with a selection of electrophilic derivatizing agents to synthesize five novel stilbene–coumarin analogues. These semisynthetic derivatives showed moderate activity against Fo32931 with only prenylated derivative exhibiting activity comparable to the natural stilbene–coumarin (1), demonstrating the key role of the phenolic group

Local functions of commercial wood volume for Pinus ponderosa Dougl. ex Laws. plantations on the Andean foothills in Neuquén province, Argentina

El objetivo de este trabajo fue evaluar el comportamiento de una serie de modelos (ocales para estimar el volumen de madera rolliza de Pinus ponderosa, en plantaciones situadas en la precordillera de la provincia del Neuquén. Se definieron 10 modelos matemáticos, capaces de predecir el volumen a partir del diámetro del árbol, de alguna función de este diámetro o de una combinación de ambos. Los elementos de decisión tomados en cuenta para evaluar los modelos comprendieron: precisión, sesgo y sencillez. En un grupo de 4 modelos destacados, V- a+b*02; V= a*D2; V= a+b*D+c*D2; V=a*Db, no se encontraron elementos de juicio que permitieran definir la superioridad de un modelo sobre otro. Los modelos de una variable predictora mostraron un comportamiento eficiente, con buena exactitud.The objective of this work was to evalúate the behavior of a series of local models to estimate the commercial wood volume of Pinus ponderosa, in plantations situated on the Andean foothills in Neuquén province. Ten functions, which are capable of predicting the volume from the diameter of the tree, from soma function of this diameter or from a combination of both have been proposed. The elemente taken into account in order to evaluate the functions include: accuracy, bias and simplicity. Within a group of four outstanding models, V=a+b*D2; V=a*D2; V=a+b*D+c*D2; V=a*Db, there were no elements to define the superiority of one over the others. The models of one predicting variable showed an efficient behavior, with a good accuracy.Facultad de Ciencias Agrarias y Forestale

Local functions of commercial wood volume for Pinus ponderosa Dougl. ex Laws. plantations on the Andean foothills in Neuquén province, Argentina

El objetivo de este trabajo fue evaluar el comportamiento de una serie de modelos (ocales para estimar el volumen de madera rolliza de Pinus ponderosa, en plantaciones situadas en la precordillera de la provincia del Neuquén. Se definieron 10 modelos matemáticos, capaces de predecir el volumen a partir del diámetro del árbol, de alguna función de este diámetro o de una combinación de ambos. Los elementos de decisión tomados en cuenta para evaluar los modelos comprendieron: precisión, sesgo y sencillez. En un grupo de 4 modelos destacados, V- a+b*02; V= a*D2; V= a+b*D+c*D2; V=a*Db, no se encontraron elementos de juicio que permitieran definir la superioridad de un modelo sobre otro. Los modelos de una variable predictora mostraron un comportamiento eficiente, con buena exactitud.The objective of this work was to evalúate the behavior of a series of local models to estimate the commercial wood volume of Pinus ponderosa, in plantations situated on the Andean foothills in Neuquén province. Ten functions, which are capable of predicting the volume from the diameter of the tree, from soma function of this diameter or from a combination of both have been proposed. The elemente taken into account in order to evaluate the functions include: accuracy, bias and simplicity. Within a group of four outstanding models, V=a+b*D2; V=a*D2; V=a+b*D+c*D2; V=a*Db, there were no elements to define the superiority of one over the others. The models of one predicting variable showed an efficient behavior, with a good accuracy.Facultad de Ciencias Agrarias y Forestale

Valeur économique de l'amélioration de l'approvisionnement en eau potable des zones rurales au Cameroun

Economic Value of the Improvment of Safe Water Supply in Rural Areas in Cameroon. A study was conducted in order to economically value the importance granted to the improvement of provision in safe water in terms of utility or willingness to pay for households living in the rural communities in Cameroon. When there are no modern water points, the provision of safe water is done in the rivers and the temporary or permanent traditional wells. The households need about 27 to 28 mn on average to go to the water source. On the average, the households draw 112.8 liters of water each day, mainly used for drinking and cooking. This task is especially incumbent upon 89% of the women. The median willingness to pay for the construction of wells is 5,600 Fcfa. The total economic value is 4.6 million Fcfa, that is about 25,500 Fcfa per household. The median willingness to pay for a fixed monthly contribution equals 950 Fcfa for 91.1% of the sampled households, against 5 Fcfa for 3.3% of the households which want to contribute to the maintenance by bucket. The presence of associations of the particular type such as churches, "djanguis", mosques, and the village dialogue committee enormously contribute to consolidate some management committees of the water points

In vitro activities of acetonic extracts from leaves of three forage legumes (Calliandra calotyrsus, Gliricidia sepium and Leucaena diversifolia) on Haemonchus contortus

AbstractObjectiveTo assess ovicidal activity of three acetonic extracts from the leaves of three forage legume, Calliandra calotyrsus (C. calotyrsus), Gliricidia sepium (G. sepium) and Leucaena diversifolia (L. diversifolia) in vitro on Haemonchus contortus (H. contortus).MethodsEggs were exposed for 24 hours to five different concentrations (0.075, 0.15, 0.3, 0.6 and 1.25 mg/mL) of acetonic extracts at room temperature (24 °C). Distilled water and 0.4% Tween were used in the bioassay as negative controls.ResultsThe later did not affect embryonation and egg hatching of H. contortus. Conversively, significant effects were obtained with the acetonic extracts of leaves of all three plants and the maximum activity was observed with the highest concentration (1.25 mg/mL). The acetonic extract of G. sepium was found to be more active (2.9% and 0.0% for embryonation and egg hatching, respectively) than the other substances 16.5% and 33.5%, respectively for C. calothyrsus, 33.7% and 33.3%, respectively for L. diversifolia.ConclusionsThese results suggest that the three forage legumes do possess ovicidal properties and further studies on larvae should be carried out

Late Paleoproterozoic mafic magmatism and the Kalahari craton during Columbia assembly

The 1.87–1.84 Ga Black Hills dike swarm of the Kalahari craton (South Africa) is coeval with several regional magmatic provinces used here to resolve the craton’s position during Columbia assembly. We report a new 1850 ± 4 Ma (U-Pb isotope dilution–thermal ionization mass spectrometry [ID-TIMS] on baddeleyite) crystallization age for one dike and new paleomagnetic data for 34 dikes of which 8 have precise U-Pb ages. Results are constrained by positive baked-contact and reversal tests, which combined with existing data produce a 1.87–1.84 Ga mean pole from 63 individual dikes. By integrating paleomagnetic and geochronological data sets, we calculate poles for three magmatic episodes and produce a magnetostratigraphic record. At 1.88 Ga, the Kalahari craton is reconstructed next to the Superior craton so that their ca. 2.0 Ga poles align. As such, magmatism forms part of a radiating pattern with the coeval ca. 1.88 Ga Circum-Superior large igneous provinc