Mamadou Sow

The Arabian Peninsula is among the major dust sources on Earth. Here, dust storms occur frequently as a result of the action of surface winds on desert surface such as the Empty Quarter Desert located in southern Arabian Peninsula. Despite being a frequent occurrence, no direct measurement of dust emission in this region existed to date. In summer 2022, the WInd-blown Sand Experiment (WISE) kicked off in the Empty Quarter area located in southern United Arab Emirates (UAE). The aim of the experiment is to quantify dust emission from this major dust source through direct observations. A full set of instrumentation is being operated to study saltation, winds, temperature, humidity, radiative fluxes, physical and optical properties of dust aerosols, atmospheric electric field, and soil properties. In this presentation, we describe the instrumentation being used in WISE UAE and we show some preliminary results during different weather regimes such as strong wind erosion, local convection, dense radiation fog and land-sea breeze. The analysis of atmospheric electric field data suggests the presence of relatively higher electric field at the onset of sea breeze occurrence and wind erosion events. The detailed investigation on relative humidity, frictional velocity, dust particle size distribution impact on the electric field will be presented. WISE is a first-of-its-kind experiment in the region and it aims ultimately at improving dust parametrizations in numerical models. We hope that this presentation at the EGU can trigger collaborations in this direction.

Background: The Expanded Program on Immunisation has made it possible to prevent more than 3 million deaths in children under 5 years. The objectives of this study were to estimate the vaccination coverage of children from 0 to 59 months and identify factors associated with incomplete vaccination coverage. Methods: A cross-sectional study was carried out in a dispensary in Conakry, Guinea between January and February 2020. Sociodemographic and vaccination information was collected from mothers of 380 randomly select children aged 0 to 59 months. Information on immunisation coverage was gathered from records vaccination cards and maternal reports. Logistic regression was used to identify factors independently associated with incomplete immunisation coverage. Results: Most (66.5%) children aged < 12 months were up-to-date with their vaccinations. Factors associated with incomplete vaccination in this age group included: unavailability of vaccination cards (adjusted odds ratio [aOR] 7.58; 95% confidence interval [CI]: 2.56-22.44) and lack of prenatal consultation attendance (aOR 2.93; 95% CI: 1.15-7.48). In contrast only 19.8% (95% CI: 13.9-26.7) of children aged 12-59 months were fully immunised. Factors associated with incomplete vaccination coverage in children aged 12-59 months included high birth order (aOR 10.23; 95% CI: 2.06-19.43), and lack of prenatal consultation attendance (aOR 5.34; 95% CI: 1.48-19.23). Conclusion: Child immunisation coverage is low in Guinea. These results highlight the need to develop strategies based on an integrated approach to overcome obstacles to childhood immunisation in Guinea.

This article presents an experimental study, performed in the BERGAME setup, dedicated to studying the collection of submicron aerosol particles by raindrops. The initial aim was to focus on the influence of the electrical charges of raindrops on the efficiency with which they collect aerosol particles. However, in the relative humidity range considered in this article (26–36%), measurements highlight a first-order role of phoretic effect for submicron aerosol particles. Indeed, measurements highlight a 100% increase in the collection efficiency for each percentage decrease in the atmospheric relative humidity. Phoretic effects are known to play a role in collection by drops; however, none of the models found in the literature predicts the same magnitude as the one presently measured. Characterization of the aerosol trajectories around the drop, accelerated to terminal velocity, seems to show a coupling between phoretic effects and rear capture. This interaction, already suggested by Grover et al., is a line of explanation for such a sharp unpredicted increase of the collection efficiency with moisture decrease.

Background: The tremendous size of the 2013-2016 West African outbreak of Ebola virus disease (EVD) resulted in a sizeable population of survivors, many reporting short-term sequelae such as arthralgia and myalgia. Objectives: We aimed to report a detailed and long-term description of patients’ musculoskeletal (MS) symptoms. Methods: We performed a cross-sectional study following systematic rheumatological screening of patients included in the Postebogui cohort (Conakry district). We used regression models to establish the magnitude of EVD as a risk factor for developing chronic MS pain by comparison with a control cohort and to establish risk factors for developing MS pain among survivors. Results: The study included 313 patients (55.6% female), with a median age of 28.2 years (IQR 21-37), and a median time from ETC discharge to rheumatological visit of 26.2 months (IQR 23-30). Chronic MS pain was reported in 216 (69%) patients, and was predominantly mechanical (48%). Enthesis and painful peripheral joints were largely involved (91%) with symmetrical distribution. Previous Ebola infection was a major risk factor for chronic MS pain (aOR, 6.662 [95% CI, 4.522–9.921]). Among survivors, increasing age (OR 1.14, 95% CI 1.08-1.22) and female gender (OR 3.58, 95% CI 1.22-11.80) were both associated with persistent MS pain, while myalgia experienced during the acute phase of EVD appeared protective (OR 0.14, 95% CI 0.04-0.42). Conclusion: Our study provides the most accurate long-term description of MS disorders among Ebola survivors. Joint and muscle pain sequelae are frequent and require specialized care. Disclosure of Interests: None declared