Mark-release-recapture experiments with Anopheles gambiae s.l. were performed during the wet seasons of 1993 and 1994 in Banambani, Mali. All recaptured mosquitoes were identified to species by PCR analysis and, when possible, by chromosomal analysis to chromosomal form. Two species of the An. gambiae complex were present: An. gambiae s.s. and An. arabiensis; their ratio differed greatly from one year to the next. Three chromosomal forms of An. gambiae s.s. were found--Bamako, Savanna and Mopti. The drier 1993 was characterized by a high frequency of An. arabiensis and of the Mopti chromosomal forms of An. gambiae s.s. These trends were consistent with large-scale geographical patterns of abundance along a precipitation gradient. We observed no difference in dispersal between the two species, nor among the chromosomal forms of An. gambiae s.s. Therefore, in this situation at least, it is reasonable to group such data on the An. gambiae complex as a whole for analysis. Population size of An. gambiae s.l. females in the village was estimated to be 9000-11,000 in 1993 and 28,000 in 1994. The corresponding numbers were somewhat higher when independently-derived values of daily survival were used. These were consistent with estimates of effective population size obtained from patterns of gene frequency change.

Investment in SARS-CoV-2 sequencing in Africa over the past year has led to a major increase in the number of sequences generated, now exceeding 100,000 genomes, used to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence domestically, and highlight that local sequencing enables faster turnaround time and more regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and shed light on the distinct dispersal dynamics of Variants of Concern, particularly Alpha, Beta, Delta, and Omicron, on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve, while the continent faces many emerging and re-emerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century.

Urban areas in Sahelian West Africa are highly vulnerable to extreme hydro‐meteorological events. In recent years, Burkina Faso has experienced several natural disasters with floods being the most frequent. This study investigates flood trends in Ouagadougou and their relationship to extreme rainfall events. Fourteen rainfall indices were analysed to characterise the frequency and intensity of extreme rainfall. A frequency analysis of annual maximum daily rainfall series was performed using three statistical distributions. The results showed that few of the rainfall indices have significant trends at 5% level over the period 1961–2015. The generalised extreme value distribution satisfactorily fit the time‐series of annual maximum daily rainfall. An analysis of media flood reports revealed that Burkina Faso experienced approximately three flood events per year throughout the period 1986–2016. In the 2000s, the number of flood events increased to five per year. Most flood events are caused by rainfall events with return periods of less than or equal to 5 years. The results indicated that the significant increase in flood risk in Ouagadougou is not only related to heavy rainfall but also due to human and environmental factors.

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RESUMELa stimulation hormonale de la production de caoutchouc abusive et inadaptée réduit considérablement la productivité de l'hévéa. Pour prévenir cette contrainte, une étude des régimes annuels de stimulation permettant aux clones PB 235 et PB 260 d'Hevea brasiliensis, à métabolisme actif, d'exprimer au mieux leurs potentialités, a été entreprise au sud-est de la Côte d'Ivoire. Les hévéas, plantés à 510 arbres/ha selon un dispositif complètement randomisé, ont été saignés en S/2 d4 et stimulés à l'Ethéphon aux fréquences annuelles de 0, 1, 2, 4, 6, 8, 13 et 26. Les paramètres mesurés ont été la production de caoutchouc, la croissance isodiamétrique, le profil physiologique et la sensibilité à l'encoche sèche des arbres. Les résultats ont révélé que la stimulation a une influence sur la production, la croissance isodiamétrique et les paramètres physiologiques des clones PB 235 et PB 260. La teneur en saccharose du latex a été un paramètre déterminant de la réponse à cette stimulation puisqu'elle a participé de l'amélioration de la productivité et surtout de l'amoindrissement du stress pouvant susciter la fatigue physiologique, voire l'encoche sèche. La sensibilité à ce syndrome est une caractéristique intrinsèque de ces clones. Pour exprimer au mieux leurs potentialités, les fréquences annuelles de stimulation respectives de 1 et 2 sont adaptées aux PB 235 et PB 260.

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Compressed earth brick (CEB) is a masonry material which has the thermal properties that are better adapted to the hot and dry climate of tropical and Sahelian context like in Burkina Faso. Despite these advantages, CEB are still not largely used in the construction sector in the city of Ouagadougou. In order to better understand the obstacles linked to this low diffusion of CEB, the present empirical study proposes a deep analysis of the social representations of construction using CEB in the urban place. The results show that four main categories of social representations coexist in the construction sector using CEB: 1) the perception of CEB as the "material for the poor", 2) the perception of CEB as "improved or precarious adobe" inherited from successive public policies to rehabilitate the material, 3) the symbolic perceptions linked to the red color of the brick and the durability of the material, and 4) the contemporary post-materialist perception (luxury materials), according to a minority of wealthy elites who have built their houses using CEB. These social representations are essential to take into consideration for the implementation of new public housing policies in general and promotion for the usage of CEB in particular. This could accompany the studies which aim at improving the technical performances of CEB and lead towards the socio-economic acceptance of the materials.