Combining High Yields and Blast Resistance in Rice (Oryza spp.): A Screening under Upland and Lowland Conditions in Benin

The future security of the supply of rice for food in Africa depends on improving the level of local production to achieve self-sufficiency. In order to cope with the existing gap between production and actual demand, combining a high level of rice blast tolerance and a high-yield potential is necessary. The current study was conducted under upland and lowland conditions in Benin to gain insight into the performance of selected blast-resistant accessions along with some currently grown varieties. This study revealed a high phenotypic variability among these accessions. Furthermore, differences in the performance of these accessions under lowland and upland conditions were observed. Principal component analysis showed their grouping in three clusters. The analysis also demonstrated a high yield potential among the blast-resistant rice accessions whether they were Oryza sativa or O. glaberrima. Furthermore, there was a significant correlation between yield and both spikelet fertility and growth cycle duration. In conclusion, the present study identified promising rice accessions for future breeding. High phenotypic variability in combination with interesting traits can help to develop new resilient varieties. Finally, when the traits correlate with yield, they can be used as markers for an early screening method for identifying promising accessions at an early stage

Les hybridations interspecifiques dans le genre Phaseolus : selection des genotypes compatibles et caracterisation des hybrides interspecifiques

La réussite de l’introgression de caractères utiles chez le haricot commun P. vulgaris à partir des deux espèces P. coccineus et P. polyanthus dépend en partie des génotypes utilisés. Ce travail vise à identifier des génotypes de Phaseolus compatibles lors des hybridations interspécifiques et à identifier les hybrides issus des croisements entre P. vulgaris utilisé comme parent mâle et les deux autres espèces utilisées comme parents femelles. Dans les croisements P. coccineus x P. vulgaris, le taux de gousses avortées audelà de 8 JAP est d’environ 12 %. Quatre gousses supposées hybrides ont été obtenues. Pour les hybridations P. polyanthus x P. vulgaris, le taux de gousses avortés au-delà de 8 JAP est d’environ 18 % et une seule gousse supposée hybride a été produite. Les hybrides issus des deux combinaisons interspécifiques ont été mis en évidence au moyen de caractères morphologiques et grâce à un marqueur moléculaire microsatellite. Les génotypes retenus pour leur bonne aptitude à la combinaison, en tenant compte des taux d’avortement au-delà de 8 JAP, sont les suivants : NI637 et G21245 pour P. vulgaris, NI889 et NI16 pour P. coccineus, NI1015 et G35348 pour P. polyanthus. Mots clés : Phaseolus, hybridations interspécifiques, caractères morphologiques, marqueur microsatellite (SSR).INTERSPECIFIC HYBRIDIZATIONSWITHIN THE GENUS PhaseolusSuccessful introgression of useful traits in common bean P. vulgaris from the two species P. coccineus and P. polyanthus depends in part to genotypes used. This work aims to identify genotypes of Phaseolus compatible during interspecific crosses and to identify hybrids from crosses between P. vulgaris used as male parent and the other two species used as female parents. In crosses P. coccineus x P. vulgaris, the rate of pod abortion 8 days after pollination (DAP) is around 12 %. Four putative hybrid pods were obtained. For hybridizations P. polyanthus x P. vulgaris, the rate of pod abortion 8 DAP is around 18 % and one putative hybrid pod was produced. The hybrid nature of one plant from each interspecific combination was confirmed using morphological characters and one microsatellite molecular marker. Genotypes selected for good combining abilities, considering pod abortion rates 8 DAP are NI637 and G21245 for P. vulgaris, NI889 and NI16 for P. coccineus, NI1015 and G35348 for P. polyanthus.Keywords : Phaseolus, interspecific hybridizations, morphological characters, microsatellite marker (SSR)

Preclinical research and development of a herbal antipyretic drug based on leaves of Ceiba pentandra (Malvaceae)

Background: Faced with the limits of synthetic antipyretic substances, in particular their involvement in the occurrence of numerous and often serious adverse effects; the challenge is in search of new antipyretics especially from the African traditional pharmacopoeia. The objective of this study was to evaluate the antipyretic activity of an aqueous extract and a formulation of Ceiba pentandra, with a view to designing an herbal antipyretic drug.Methods: Trials of formulation of an antipyretic syrup with leaves extract of Ceiba pentandra were carried out. The antipyretic activity was investigated by the bewer's yeast induced pyrexia. Physicochemical and microbiological stability tests were carried out on the syrup.Results: It was found with the extract an antipyretic activity at doses of 125 mg/kg and 150 mg/kg. The effect was greater for the 125 mg/kg dose with inhibition percentages ranging from 27.58% to 71.25%. This antipyretic activity was early (from 30 minutes) and was preserved during the four hours of the experiment. The syrup dosed at 125 mg/kg gave an activity similar to that of the extract by significantly reducing the hyperthermia in the rats. Regarding the stability tests, the syrup remained stable both physico-chemically and microbiologically throughout the study period (28 days) both when exposed to low temperature (5 °±3 ° C) and at high temperature (40°±2° C).Conclusions: Ceiba pentandra leaves have antipyretic activity and could be used for the development of an herbal antipyretic drug

Evaluation de l’effet repulsif d’extraits de neem (Azadirachta indica A. Juss., 1830) sur le charançon de la patate douce (Cylas puncticollis Boheman, 1833) en condition de laboratoire a Korhogo, nord de la Cote d’Ivoire

Une stratégie de gestion intégrée des insectes nuisibles à la culture de la patate douce a été élaborée pour réduire les pertes dues à ceux-ci. Ainsi, les propriétés répulsives des extraits de feuilles et d’amandes de neem ont été évaluées sur Cylas puncticollis, un charançon de la patate douce. Pour ce faire, quatre concentrations d’extraits ont été préparées à raison de quatre répétitions par concentration. Le test a consisté à la détermination du pourcentage de charançons présents dans la zone traitée. Chacune des concentrations d’extraits a été appliquée sur la moitié d’un papier buvard placé dans une boite de Pétri de 9 cm de diamètre et sur lequel 10 charançons ont été posés. Les effets répulsifs des extraits ont été comparés à ceux d’un insecticide chimique et l’eau distillée. Le test avec 20 cL/L d’extraits de feuilles a causé 85 % de répulsion contre 45 % pour les amandes à 25 g/L. Les extraits ont significativement causé plus de répulsion que l’eau distillée et l’insecticide chimique. Les tests ont révélé un potentiel plus répulsif des extraits de feuilles comparé à celui des amandes. Les extraits de neem pourraient constituer une alternative crédible à la lutte chimique pour la protection de la patate douce contre ce charançon. English title: Evaluation of the repellent effect of neem extracts (Azadirachta indica A. Juss., 1830) on the sweet potato weevil (Cylas puncticollis Boheman, 1833) under laboratory conditions in Korhogo, northern Côte d’Ivoire Abstract An integrated pest management strategy for sweet potatoes has been developed to reduce pest losses. Thus, the repellent properties of neem leaf and kernel extracts were evaluated on Cylas puncticollis, a sweet potato weevil. For this purpose, four concentrations of extracts were prepared with four replicates per concentration. The test consisted of determining the percentage of weevils in the treated area. Each of the extract concentrations was applied to half of a blotting paper placed in 9 cm diameter Petri dishes on which 10 weevils were placed. The repellent effects of the extracts were compared to those of a chemical insecticide and distilled water. Test with 20 cL/L leaf extract caused 85% repellence compared to 45% for almonds at 25 g/L. Compared to the chemical insecticide and distilled water, the extracts caused significantly more repellence. The tests revealed a higher repellent potential of the leaf extracts compared to those of almonds. Neem extracts could be a credible alternative to chemical control for the protection of sweet potato against this weevil. Keywords: Neem extracts, Repellent effect, Sweet potato, Cylas puncticolli

Caractérisation et évaluation des vivriers dans un système d’exploitation agricole à base de coton dans le département de Sinématiali – Côte d’Ivoire

La présente étude visait à caractériser les systèmes d’exploitation agricoles à base de coton, puis d’évaluer l’importance des vivriers dans ces  systèmes. Elle a été conduite sur un échantillon de 40 exploitants agricoles répartis dans 8 villages de Sinématiali. Les résultats ont indiqué que les systèmes dominants sont le maïs (3,675 ha) et le coton (3,14 ha). Ensuite viennent, l’arachide (1,125 ha), le riz (0,906 ha) le haricot (0,306 ha), le mil (0,297 ha) et l’igname (0,194 ha). Par ailleurs, le compte  d’exploitation révèle que les vivriers ont les marges nettes à l’hectare les plus élevés avec respectivement 245 727,5 FCFA, pour le riz ; 58 004,7 FCFA pour le maïs ; 209 738,4 FCFA pour l’arachide et 239 472 FCFA pour le mil contre 5 085,1 FCFA pour le coton. L’analyse du ratio de la marge brute sur le coût variable totale montre que 1 FCFA investi sur les parcelles de vivriers rapporte respectivement 4,09 F ; 1,54 F ; 7,44 F et 12,09 FCFA pour le riz, le maïs, l’arachide et le mil contre 0,36 FCFA pour le coton. Aussi, cette étude indique que les vivriers contribuent à hauteur de 98%, au revenu annuel du paysan contre 2% pour le coton. Malgré cette faible contribution du coton dans les revenus du paysan, sa culture permet aux exploitants d’accéder aux intrants et aux matériels agricoles modernes pour accroître les superficies et les rendements agricoles.Mots clés : Systèmes de culture, coton, vivriers, marge brute, Côte d’Ivoire

Emissions from the road traffic of West African cities : assessment of vehicle fleet and fuel consumption

Traffic source emission inventories for the rapidly growing West African urban cities are necessary for better characterization of local vehicle emissions released into the atmosphere of these cities. This study is based on local field measurements in Yopougon (Abidjan, C&ocirc te d&rsquo Ivoire) in 2016 a site representative of anthropogenic activities in West African cities. The measurements provided data on vehicle type and age, traveling time, fuel type, and estimated amount of fuel consumption. The data revealed high traffic flow of personal cars on highways, boulevards, and backstreets, whereas high flows of intra-communal sedan taxis were observed on main and secondary roads. In addition, the highest daily fuel consumption value of 56 L&middot day&minus 1 was recorded for heavy vehicles, while the lowest value of 15 L&middot 1 was recorded for personal cars using gasoline. This study is important for the improvement of uncertainties related to the different databases used to estimate emissions either in national or international reports. This work provides useful information for future studies on urban air quality, climate, and health impact assessments in African cities. It may also be useful for policy makers to support implementation of emission reduction policies in West African cities. Document type: Articl

Retrospective analysis of a cohort of HIV-infected patients on antiretroviral therapy in Abidjan (2003 to 2017)

Background: Antiretroviral therapy (ART) has been successful in improving clinical outcomes for HIV-positive patients, but efforts are needed to improve life expectancy and quality of life. This study aimed to analyze a long-term ART cohort and assess patients' life expectancy. Methods: A retrospective cohort study was conducted at the infectious and tropical diseases department of the University Teaching Hospital of Treichville from 2003 to 2017. Data analysis was done using VBA access and XLSTAT 2018 excel software. Patients on post-exposure chemoprophylaxis and prevention of mother-to-child transmission were excluded. Results: Out of 19,567 patient records, 49.60% were included, 72.43% were in 1st line, and 50.10% were over 50 years old, mostly female 58.49%, 98.4% HIV1. 74.31% had a CD4/mm3 (Nadir) count <350. The patients were essentially on the 2IN+INN regimen (72.31%), TDF + XTC + EFV (20.57%). The average duration under treatment 6.15 [0-13.67] ±3.94 years, the average duration under a line of treatment 4.33 [0-14.04] ±2.96 years. Life expectancy was 10.37 years. It is higher in patients on 2IN+IPr (12.21 years) versus 10.12 years in patients on 2IN+INN. The comparison of duration on a line according to the CD4 counts and the line of treatment did not show a significant difference p>0.05. Conclusions: The study concluded that ART significantly improved the life expectancy of patients, adherence could be improved to further enhance the benefits of ART. The use of new combinations of ART may reduce events related to non-compliance

Exposure to indoor and outdoor air pollution among children under five years old in urban area

Indoor air pollution associated with cooking and heating biomass fuel burning is estimated to be responsible for 7 million deaths in 2016 and most of these deaths occur in low and middle income countries. In Côte d'Ivoire, 73% of the population is reported using biomass (charcoal or wood) for cooking. The active device 3M EVM-7 was used to measure PM2.5 daily average concentrations inside and outside households in areas close (Andokoi) and far (Lubafrique) to an industrial zone in two popular neighborhoods of Yopougon, the largest and most populated municipality of the city of Abidjan (Côte d’Ivoire). PM2.5 daily average concentrations indoors and outdoors are respectively 121±12 µg/m3 and 117±8 µg/m3 in Andokoi and 32±3 µg/m3 and 41±4 µg/m3 in Lubafrique well above the World Health Organization guideline value (25 µg/m3) for air quality. Using multivariable models, the results were the number of windows in bedrooms and kitchens located outdoor were negatively correlated with the concentration of indoor PM2.5. The outdoor concentrations of PM2.5, were higher according to the cooking fuel type

Limited efficacy of repeated praziquantel treatment in Schistosoma mansoni infections as revealed by highly accurate diagnostics, PCR and UCP-LF CAA (RePST trial)

BACKGROUND: Most studies assessing praziquantel (PZQ) efficacy have used relatively insensitive diagnostic methods, thereby overestimating cure rate (CR) and intensity reduction rate (IRR). To determine accurately PZQ efficacy, we employed more sensitive DNA and circulating antigen detection methods. METHODOLOGY: A sub-analysis was performed based on a previously published trial conducted in children from Cote d'Ivoire with a confirmed Schistosoma mansoni infection, who were randomly assigned to a standard (single dose of PZQ) or intense treatment group (4 repeated doses of PZQ at 2-week intervals). CR and IRR were estimated based on PCR detecting DNA in a single stool sample and the up-converting particle lateral flow (UCP-LF) test detecting circulating anodic antigen (CAA) in a single urine sample, and compared with traditional Kato-Katz (KK) and point-of-care circulating cathodic antigen (POC-CCA). PRINCIPAL FINDINGS: Individuals positive by all diagnostic methods (i.e., KK, POC-CCA, PCR, and UCP-LF CAA) at baseline were included in the statistical analysis (n = 125). PCR showed a CR of 45% (95% confidence interval (CI) 32-59%) in the standard and 78% (95% CI 66-87%) in the intense treatment group, which is lower compared to the KK results (64%, 95% CI 52-75%) and 88%, 95% CI 78-93%). UCP-LF CAA showed a significantly lower CR in both groups, 16% (95% CI 11-24%) and 18% (95% CI 12-26%), even lower than observed by POC-CCA (31%, 95% CI 17-35% and 36%, 95% CI 26-47%). A substantial reduction in DNA and CAA-levels was observed after the first treatment, with no further decrease after additional treatment and no significant difference in IRR between treatment groups. CONCLUSION/SIGNIFICANCE: The efficacy of (repeated) PZQ treatment was overestimated when using egg-based diagnostics. Quantitative worm-based diagnostics revealed that active Schistosoma infections are still present despite multiple treatments. These results stress the need for using accurate diagnostic tools to monitor different PZQ treatment strategies, in particular when moving toward elimination of schistosomiasis. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov, NCT02868385

Spatial variation and socio-economic determinants of Plasmodium falciparum infection in northeastern Tanzania

<p>Abstract</p> <p>Background</p> <p>Malaria due to <it>Plasmodium falciparum </it>is the leading cause of morbidity and mortality in Tanzania. According to health statistics, malaria accounts for about 30% and 15% of hospital admissions and deaths, respectively. The risk of <it>P. falciparum </it>infection varies across the country. This study describes the spatial variation and socio-economic determinants of <it>P. falciparum </it>infection in northeastern Tanzania.</p> <p>Methods</p> <p>The study was conducted in 14 villages located in highland, lowland and urban areas of Korogwe district. Four cross-sectional malaria surveys involving individuals aged 0-19 years were conducted during short (Nov-Dec) and long (May-Jun) rainy seasons from November 2005 to June 2007. Household socio-economic status (SES) data were collected between Jan-April 2006 and household's geographical positions were collected using hand-held geographical positioning system (GPS) unit. The effects of risk factors were determined using generalized estimating equation and spatial risk of <it>P. falciparum </it>infection was modelled using a kernel (non-parametric) method.</p> <p>Results</p> <p>There was a significant spatial variation of <it>P. falciparum </it>infection, and urban areas were at lower risk. Adjusting for covariates, high risk of <it>P. falciparum </it>infection was identified in rural areas of lowland and highland. Bed net coverage levels were independently associated with reduced risk of <it>P. falciparum </it>by 19.1% (95%CI: 8.9-28.2, p < 0.001) and by 39.3% (95%CI: 28.9-48.2, p < 0.001) in households with low and high coverage, respectively, compared to those without bed nets. Households with moderate and lower SES had risk of infection higher than 60% compared to those with higher SES; while inhabitants of houses built of mud walls were at 15.5% (95%CI: 0.1 - 33.3, p < 0.048) higher risk compared to those living in houses built by bricks. Individuals in houses with thatched roof had an excess risk of 17.3% (95%CI: 4.1 - 32.2, p < 0.009) compared to those living in houses roofed with iron sheet.</p> <p>Conclusions</p> <p>There was high spatial variation of risk of <it>P. falciparum </it>infection and urban area was at the lowest risk. High bed net coverage, better SES and good housing were among the important risk factors associated with low risk of <it>P. falciparum </it>infection.</p