[Evaluation of malaria rapid diagnostic test Optimal-IT® pLDH along the Plasmodium falciparum distribution limit in Mauritania].

Performance of the malaria Rapid Diagnostic Test (RDT) OptiMal-IT® was evaluated in Mauritania where malaria is low and dependent on a short transmission season. Slide microscopy was considered as the reference method of diagnosis. Febrile patients with suspected malaria were recruited from six health facilities, 3 urban and 3 rural, during two periods (December 2011 to February 2012, and August 2012 to March 2013). Overall, 780 patients were sampled, with RDT and thick blood film microscopy results being obtained for 759 of them. Out of 774 slides examined, of which 200 were positive, P. falciparum and P. vivax mono-infections were detected in 63.5% (127) and 29.5% (59), while P. falciparum/P. vivax coinfections were detected in 7% (14). Both species were observed in all study sites, although in significantly different proportions. The proportions of thick blood film and OptiMal-IT® RDT positive individuals was 26.3% and 30.3% respectively. Sensitivity and specificity of OptiMal-IT® RDT were 89% [95% CI, 84.7-93.3] and 91.1% [88.6-93.4]. Positives and negative predictive values were 78.1% [72.2-83.7] and 95.9% [94.1-97.5]. These diagnostic values are similar to those generally reported elsewhere, and support the use of RDTs as the main diagnostic tool for malaria in Mauritanian health facilities. In the future, choice of RDTs to be used must take account of thermostability in a hot, dry environment and their ability to detect P. falciparum and P. vivax

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

Physiological and genetic control of transpiration efficiency in African rice, Oryza glaberrima Steud

Improving crop water use efficiency, the amount of carbon assimilated as biomass per unit of water used by a plant, is of major importance as water for agriculture becomes scarcer. In rice, the genetic bases of transpiration efficiency, the derivation of water use efficiency at the whole-plant scale, and its putative component trait transpiration restriction under high evaporative demand remain unknown. These traits were measured in 2019 in a panel of 147 African rice (Oryza glaberrima) genotypes known to be potential sources of tolerance genes to biotic and abiotic stresses. Our results reveal that higher transpiration efficiency is associated with transpiration restriction in African rice. Detailed measurements in a subset of highly contrasted genotypes in terms of biomass accumulation and transpiration confirmed these associations and suggested that root to shoot ratio played an important role in transpiration restriction. Genome wide association studies identified marker-trait associations for transpiration response to evaporative demand, transpiration efficiency, and its residuals, with links to genes involved in water transport and cell wall patterning. Our data suggest that root-shoot partitioning is an important component of transpiration restriction that has a positive effect on transpiration efficiency in African rice. Both traits are heritable and define targets for breeding rice with improved water use strategies.This work was supported by the Institut de Recherche pour le Développement, the CGIAR Research Program (CRP) on rice-agrifood systems (RICE, 2017-2022) and the Agence Nationale de la Recherche (grant ANR-17-MPGA-0011 to VV). Financial support by the Access to Research Infrastructures activity in the Horizon 2020 Programme of the EU (EPPN2020 Grant Agreement 731013) is gratefully acknowledged. PA was supported by a doctoral fellowship from the French Ministry of Higher Education. BEE was supported by the Centre National de la Recherche Scientifique et Technologique of Gabon. The authors acknowledge the IRD iTrop HPC (South Green Platform) at IRD Montpellier for providing HPC resources (https://bioinfo.ird.fr, http://www.southgreen.fr)

An introduction to the SCOUT-AMMA stratospheric aircraft, balloons and sondes campaign in West Africa, August 2006: rationale and roadmap

A multi-platform field measurement campaign involving aircraft and balloons took place over West Africa between 26 July and 25 August 2006, in the frame of the concomitant AMMA Special Observing Period and SCOUT-O3 African tropical activities. Specifically aiming at sampling the upper troposphere and lower stratosphere, the high-altitude research aircraft M55 Geophysica was deployed in Ouagadougou (12.3° N, 1.7° W), Burkina Faso, in conjunction with the German D-20 Falcon, while a series of stratospheric balloon and sonde flights were conducted from Niamey (13.5° N, 2.0° E), Niger. The stratospheric aircraft and balloon flights intended to gather experimental evidence for a better understanding of large scale transport, assessing the effect of lightning on NOx production, and studying the impact of intense mesoscale convective systems on water, aerosol, dust and chemical species in the upper troposphere and lower stratosphere. The M55 Geophysica carried out five local and four transfer flights between southern Europe and the Sahel and back, while eight stratospheric balloons and twenty-nine sondes were flown from Niamey. These experiments allowed a characterization of the tropopause and lower stratosphere of the region. We provide here an overview of the campaign activities together with a description of the general meteorological situation during the flights and a summary of the observations accomplished

Overexpression of a Common Wheat Gene TaSnRK2.8 Enhances Tolerance to Drought, Salt and Low Temperature in Arabidopsis

Drought, salinity and low temperatures are major factors limiting crop productivity and quality. Sucrose non-fermenting1-related protein kinase 2 (SnRK2) plays a key role in abiotic stress signaling in plants. In this study, TaSnRK2.8, a SnRK2 member in wheat, was cloned and its functions under multi-stress conditions were characterized. Subcellular localization showed the presence of TaSnRK2.8 in the cell membrane, cytoplasm and nucleus. Expression pattern analyses in wheat revealed that TaSnRK2.8 was involved in response to PEG, NaCl and cold stresses, and possibly participates in ABA-dependent signal transduction pathways. To investigate its role under various environmental stresses, TaSnRK2.8 was transferred to Arabidopsis under control of the CaMV-35S promoter. Overexpression of TaSnRK2.8 resulted in enhanced tolerance to drought, salt and cold stresses, further confirmed by longer primary roots and various physiological characteristics, including higher relative water content, strengthened cell membrane stability, significantly lower osmotic potential, more chlorophyll content, and enhanced PSII activity. Meanwhile, TaSnRK2.8 plants had significantly lower total soluble sugar levels under normal growing conditions, suggesting that TaSnRK2.8 might be involved in carbohydrate metabolism. Moreover, the transcript levels of ABA biosynthesis (ABA1, ABA2), ABA signaling (ABI3, ABI4, ABI5), stress-responsive genes, including two ABA-dependent genes (RD20A, RD29B) and three ABA-independent genes (CBF1, CBF2, CBF3), were generally higher in TaSnRK2.8 plants than in WT/GFP controls under normal/stress conditions. Our results suggest that TaSnRK2.8 may act as a regulatory factor involved in a multiple stress response pathways

Impacts of 1.5°C Global Warming on Natural and Human Systems

An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate povert