Quality of hydro-alcoholic products used in Senegal: pilot study

Antisepsis and disinfection have always played an important role in the fight against infectious diseases. The use of these products has been effective in breaking the chain of transmission of microorganisms. Today, with the advent of COVID-19, the main recommendations are, among other things, physical distance and the use of antiseptic products, including hydro-alcoholic products. In Senegal, with poor regulations on the acquisition and distribution of antiseptics and disinfectants, this situation has led to a proliferation of antiseptics and disinfectants on the national market. this work aimed to study the quality of hydroalcoholic products found in the trade. We evaluated ten samples of hydro-alcohol products collected during the month of March 2020. Physical and microbiological controls were performed at the National Drug Control Laboratory. The alcohol content of the samples ranged from 63 to 85% and were consistent with WHO recommendations except for samples E3 and E5. The pH values varied between 4.02 and 6.64 and the densities of the hydro-alcoholic gel samples ranged from 0.84 to 0.92 g/cm3; E2, E4, E5, E6 samples had densities greater than 0.89 g/cm3. The samples of hydro-alcoholic products all conformed to the sterility test and no microbiological contamination was observed. Antimicrobial activities of the hydro-alcoholic samples tested ranged from 58.3 to 100% with two samples showing no activity (E2 and E5). In view of the results of this study, it would be relevant to expand and deepen investigations by a significant increase in the number of samples and by carrying out as complete an analysis as possible

Etude physico-chimique et minéralogique comparative des attapulgites de Mbodiène (Sénégal) et de Mormoiron (France)

La valorisation des ressources locales constitue un impératif afin d’atteindre des objectifs de développement durable. Cette étude a consisté à évaluer les caractéristiques physiques, chimiques et minéralogiques d’une argile provenant de Mbodiène (Sénégal), l’attapulgite, comparativement avec un médicament antidiarrhéique, constitué d’attapulgite, dénommé Actapulgite®. L’échantillon d’attapulgite brute a été purifié avec une solution de HNO3 1M. Une étude morphologique effectuée par visualisation à la Microscopie Electronique à Balayage a montré pour les deux argiles étudiées, une structure fibreuse caractéristique de la palygorskite, représentant le minéral dominant. L’analyse chimique par la spectrométrie à fluorescence X a donné pour l’attapulgite purifiée : 65,69% Si, 7,89% Al, 5,92% Fe, 17,90% Mg, 0,43% Ca et 0,93% K contre respectivement 63,98 % Si, 12,92% Al, 10,32% Fe, 6,20% Mg, 2,48% Ca et 2,25% K pour l’Actapulgite®. La diffraction aux rayons X a montré une présence de palygorskite, quartz et carbonates dans les échantillons étudiés. L’étude des isothermes d’adsorption a montré une surface spécifique nettement plus élevée pour l’attapulgite purifiée, 138,96 m2.g-1 contre 98,72 m2.g-1 pour l’Actapulgite®. Ces résultats ont montré que l’attapulgite de Mbodiène pourrait être utilisée comme antidiarrhéique orale après lavage à l’eau et séchage.© 2016 International Formulae Group. All rights reservedMots clés: Argile, attapulgite, antidiarrhéique, SénégalEnglish Title: Physico-chemical and mineralogical comparative study of attapulgites Mbodiène (Senegal) and Mormoiron (France)English AbstractThe development of local resources is imperative to achieve sustainable development goals. This study was to assess physical, chemical and mineralogical characteristics of a clay from Mbodiène (Senegal), named attapulgite, compared with Actapulgite® (antidiarrheal drug), composed of attapulgite. A sample of attapulgite from Mbodiène was purified with a 1M HNO3 solution to remove impurities including carbonates. A morphological study using Scanning Electron Microscopy showed for both types of clay studied, a fibrous structure characteristic of palygorskite which represent major mineral. Chemical analysis by XRF spectrometry gave for purified attapulgite: 65.69% Si, 7.89% Al, 5.92% Fe, 17.90% Mg, 0.43% Ca and 0.93% K against respectively 63.98% Si, 12.92% Al, 10.32% Fe, 6.20% Mg, 2.48% Ca and 2.25% K for Actapulgite®. X-ray diffraction showed the presence of palygorskite, quartz and carbonates for both samples studied. The study of adsorption isotherms showed a significantly higher surface area for purified attapulgite, 138.96 m2.g-1 versus 98.72 m2.g-1 for Actapulgite®. These results have shown that Mbodiène attapulgite compared to Actapulgite®, could be used as an oral antidiarrheal after washing with water and drying.© 2016 International Formulae Group. All rights reserved.Keywords: Clay, attapulgite, antidiarrheal, Senega

Senegal: Presidential elections 2019 - The shining example of democratic transition immersed in muddy power-politics

Whereas Senegal has long been sold as a showcase of democracy in Africa, including peaceful political alternance, things apparently changed fundamentally with the Senegalese presidentials of 2019 that brought new configurations. One of the major issues was political transhumance that has been elevated to the rank of religion in defiance of morality. It threatened political stability and peace. In response, social networks of predominantly young activists, created in 2011 in the aftermath of the Arab Spring focused on grass-roots advocacy with the electorate on good governance and democracy. They proposed a break with a political system that they consider as neo-colonialist. Moreover, Senegal’s justice is frequently accused to be biased, and the servility of the Constitutional Council which is in the first place an electoral court has often been denounced

Riziculture pluviale de bas-fonds dans la région de Sédhiou (Sénégal) : contraintes de production et stratégie d’adaptation

International audienc

Influence of initial soil moisture in a regional climate model study over West Africa - Part 1: Impact on the climate mean

International audienceThe impact of soil moisture initial conditions on the mean climate over West Africa was examined using the latest version of the regional climate model of the International Centre for Theoretical Physics (RegCM4) at a 25 km horizontal resolution. The soil moisture reanalysis of the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis of the 20th century (ERA-20C) was used to initialize the control experiment, while its minimum and maximum values over the entire domain were used to establish the respective initial dry and wet soil moisture conditions (hereafter referred to as dry and wet experiments, respectively). For the respective control, wet and dry experiments, an ensemble of five runs from June to September was performed. In each experiment, we analyzed the two idealized simulations most sensitive to the dry and wet soil moisture initial conditions. The impact of soil moisture initial conditions on precipitation in West Africa is linear over the Central and West Sahel regions, where dry (wet) experiments lead to a rainfall decrease (increase). The strongest precipitation increase is found over the West Sahel for wet experiments, with a maximum change value of approximately 40 %, whereas the strongest precipitation decrease is found for dry experiments over the Central Sahel, with a peak change of approximately −4 %. The sensitivity of soil moisture initial conditions can persist for 3-4 months (90-120 d) depending on the region. However, the influence on precipitation is no longer than 1 month (between 15 and 30 d). The strongest temperature decrease is located over the Central and West Sahel, with a maximum change of approximately −1.5 °C in wet experiments, whereas the strongest temperature increase is found over the Guinea coast and Central Sahel for the dry experiments, with a maximum change of around 0.6 °C. A significant impact of soil moisture initial conditions on the surface energy fluxes is noted: in the wet (dry) experiments, a cooling (warming) of the surface temperature is associated with a decrease (increase) in sensible heat flux, an increase (decrease) in latent heat flux and a decrease (increase) in the boundary layer depth. Part 2 of this study (Koné et al., 2022) investigates the influence of soil moisture initial conditions on climate extremes

Influence of initial soil moisture in a regional climate model study over West Africa - Part 2: Impact on the climate extremes

International audienceThe influence of soil moisture initial conditions on the climate extreme indices over West Africa was investigated using the fourth generation of the International Centre for Theoretical Physics regional climate model (non-hydrostatic) coupled with version 4.5 of the Community Land Model (RegCM4-CLM4.5) at a 25 km spatial resolution. We initialized the control experiments with the reanalysis soil moisture data from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis of the 20th century (ERA-20C), while we initialized the dry and wet experiments with the maximum and minimum soil moisture values over the West Africa domain, respectively. For each experiment, an ensemble of five runs was performed for 5 years (2001-2005) with soil moisture initial conditions for the runs prescribed on 1 June and the simulations being performed over 4 months (122 d) from June to September. The performance of RegCM4-CLM4.5 with respect to simulating the 10 extreme rainfall and temperature indices used in this study is presented. The results are then discussed for the two idealized simulations that are most sensitive to the dry and wet soil moisture initial conditions in order to highlight the impacts beyond the limits of soil moisture internal forcing in the model. Over the Central Sahel, dry (wet) experiments lead to a decrease (increase) in precipitation extreme indices related to the number of events, but this was not seen for indices related to the intensity of the events. Soil moisture initial conditions unequally affect the daily minimum and maximum temperatures. The strongest impact is found on the maximum temperature: wet (dry) experiments decrease (increase) the maximum temperature over the whole region. Over the Central Sahel, wet (dry) experiments lead to a decrease (increase) in the maximum values of the minimum temperature

Influence of initial soil moisture in a Regional Climate Model study over West Africa. Part 2: Impact on the climate extremes

Abstract. The influence of the anomalies in initial soil moisture on the climate extreme over West Africa is investigated using the fourth generation of Regional Climate Model coupled to the version 4.5 of the Community Land Model (RegCM4-CLM4.5). We applied the initial soil moisture on June 1st for two summers June–July–August–September (JJAS) 2003 and JJAS 2004 (Resp. wet and dry year in the region of interest) with 25 km of spatial resolution. We initialized the control runs with the reanalysis soil moisture of the European Centre Meteorological Weather Forecast's reanalysis of the 20th century (ERA20C), while for the dry and wet experiments, we initialized the soil moisture respectively at the wilting points and field capacity. The impact on extreme precipitation indices of the initial soil moisture, especially over the central Sahel, is homogeneous, i.e. dry (wet) experiments tend to decrease (increase) precipitation extreme indices only for precipitation indices related to the number of precipitation events, not for those related to the intensity of precipitation events. Overall, the impact on temperature extremes of the anomalies in initial soil moisture is more significant compared to precipitation extremes. Initial soil moisture anomalies unequally affect daily minimum and maximum temperature. A stronger impact is found on maximum temperature than minimum temperature. Over the entire West African domain, wet (dry) experiments cause a decrease (increase) in maximum temperature. The strongest impacts on minimum temperature indices are found mainly in wet experiments, on the Sahara where we found the higher values of the maximum and minimum daily minimum temperature indices (resp. TNx and TNn). The performance of RegCM4-CLM4.5 in simulating the ten (10) extreme rainfall and temperature indices used in this study is also highlighted

Influence of initial soil moisture in a Regional Climate Model study over West Africa: Part 1: Impact on the climate mean

Abstract. The impact of the anomalies in initial soil moisture in later spring on the subsequent mean climate over West Africa is examined using the latest version of Regional Climate Model of the International Centre for Theoretical Physics (RegCM4). We performed this sensitivity studies over the West African domain, for June–July–August–September (JJAS) 2003 (wet year) and JJAS 2004 (a dry year) at the horizontal resolution of 25 km × 25 km. The reanalysis soil moisture of the European Centre Meteorological Weather Forecast's reanalysis of the 20th century (ERA20C) were used to initialize the control runs, whereas we initialized the soil moisture at the wilting points and field capacity respectively in dry and wet experiments. The impact of the anomalies in initial soil moisture on the precipitation in West Africa is homogeneous only over the central Sahel where dry (wet) experiments lead to rainfall decrease (increase). The strongest impact on precipitation in wet and dry experiments is found respectively over west and central Sahel with the peak of change about respectively 40 % and −8 %. The impact of the anomalies in initial soil moisture can persist for three or even four months, however the significance influence on precipitation, greater than 1 mm day−1, of the impact of the anomalies in initial soil moisture is much shorter, no longer than one month. The effect of soil moisture anomalies is mostly confined to the near-surface climate and in the upper troposphere. Overall, the impact of the anomalies in initial soil moisture is greater on temperature than on precipitation over most areas studied. The strongest homogeneous impacts of the anomalies in initial soil moisture on temperature is located over the central Sahel with the peak of change at −1.5 °C and 0.5 °C respectively in wet and dry experiments. The influence of initial the anomalies in initial soil moisture on the precipitation mechanism is also highlighted. We will investigate in the Part II of this study the influence of the anomalies in initial soil moisture on climate extremes

SIMULATING THE IMPACT OF VARYING VEGETATION ON WEST AFRICAN MONSOON SURFACE FLUXES USING A REGIONAL CONVECTION-PERMITTING MODEL

This study assessed the sensitivity of West African climate to varying vegetation fractions. The assessment of a such relationship is critical in understanding the interactions between land surface and atmosphere. Two sets of convection-permitting simulations from the UK Met Office Unified Model at 12 km horizontal resolution covering the monsoon period May-September (MJJAS) were used, one with fixed vegetation fraction (MF-V) and the other with time-varying vegetation fraction (MV-V). Vegetation fractions are based on MODIS retrievals between May and September. We focused on three climatic zones over West Africa: Guinea Coast, Sudanian Sahel, and the Sahel while investigating heat fluxes, temperature, and evapotranspiration. Results reveal that latent heat fluxes are the most strongly affected by vegetation fraction over the Sahelian and Sudanian regions while sensible heat fluxes are more impacted over the Guinea Coast and Sudanian Sahel. Also, in MV-V simulation there is an increase in evapotranspiration mainly over the Sahel and some specific areas in Guinea Coast from June to September. Moreover, it is noticed that high near surface temperature is associated with a weak vegetation fraction, especially during May and June. Finally, varying vegetation seems to improve the simulation of surface energy fluxes and in turn impact on climate parameters. This suggests that climate modellers should prioritise the use of varying vegetation option to improve the representation of the West African climate system

Effect of the African greenbelt position on West African summer climate: a regional climate modeling study

International audienceThis modeling study is conducted to examine the potential impact of the reforestation (greenbelt) location (either in Sahel or in Guinean region) on West African summer climate system. To this end, three simulations using the regional climate model RegCM4 driven by ERA-Interim reanalysis were performed at 50 km horizontal resolution over a West African domain for the period 2000-2011. The first experiment, namely the control (CTRL), uses the standard vegetation cover, while the two others incorporate throughout the model integration, a zonal reforestation band of evergreen broadleaf over different locations: (i) over a 13° N-17° N band latitudes in a Sahel-Sahara region (experiment hereafter referred to as GB15N) and (ii) between 8.5° N-11.5° N in the Guinea Coast region (experiment hereafter referred to as GB10N). A comparison of the CTRL experiment with observation reveals a faithful reproduction of the mean boreal and summer seasonal precipitation pattern, though substantial dry/wet biases remain, especially in the Atlantic Ocean. In addition, the seasonal cycle over sub-regions matches satisfactory the observed pattern. The GB15N reforestation leads to a precipitation increase in the range of 2-4 mm/day over the forested areas, whereas in the GB10N reforestation, precipitation increase is weaker and not necessarily located in the forested areas. Temperature cooling is observed over the reforested area and may be explained by a decrease of ground heat flux related to a reduction of the surface albedo