Contribution à l'étude de l'échantillonnage non uniforme dans le domaine de la radio intelligente.

In this work we consider the problem of designing an effective sampling scheme for sparse multi-band signals. Based on previous results on periodic non-uniform sampling (Multi-Coset) and using the well known Non-Uniform Fourier Transform through Bartlett’s method for Power Spectral Density estimation, we propose a new sampling scheme named the Dynamic Single Branch Non-uniform Sampler (DSB-NUS). The idea of the proposed scheme is to reduce the average sampling frequency, the number of samples collected, and consequently the power consumption of the Analog to Digital Converter (ADC). In addition to that our proposed method detects the location of the bands in order to adapt the sampling rate. In this thesis, we show through simulation results that compared to existing multi-coset based samplers, our proposed sampler provides superior performance, both in terms of sampling rate and energy consumption. It is notconstrained by the inflexibility of hardware circuitry and is easily reconfigurable. We also show the effect of the false detection of active bands on the average sampling rate of our new adaptive non-uniform sub-Nyquist sampler scheme.Nous proposons un nouveau schéma d’échantillonnage non uniforme périodique appelé Système d’Échantillonnage Non Uniforme en Radio Intelligente (SENURI). Notre schéma détecte la localisation spectrale des bandes actives dans la bande totale échantillonnée afin de réduire la fréquence moyenne d’échantillonnage, le nombre d’échantillons prélevé et par conséquent la consommation d’énergie au niveau du traitement numérique. La fréquence moyenne d’échantillonnage du SENURI dépend uniquement du nombre de bandes contenues dans le signal d’entrée x(t). Il est nettement plus performant, en termes d’erreur quadratique, qu’une architecture classique d’échantillonnage non uniforme périodique constituée de p branches, lorsque le spectre de x(t) change dynamiquement

Conception d’une ingénierie de la formation dans l’administration publique : cas de la Direction des Ressources Humaines du Secteur de l’Education du Mali (DRH-SE)

Cet article a comme objectif de mettre en place des programmes d’ingénierie de formation capables d’offrir les compétences nécessaires, pour assurer une prestation performante dans l’administration Malienne en général et à la Direction des Ressources Humaines du Secteur de l’Education1 en particulier. En effet, pour développer une économie, et améliorer la qualité de vie des individus, il faut accroître les compétences des ressources humaines. L’amélioration des aptitudes des professionnels Rh contribue à la croissance économique et, à l’inverse, les pays dont le système de développement des ressources humaines est déficient se retrouvent hautement impacter par un bas niveau de formation et de productivité. Nous avons adopté un positionnement épistémologique interpretativiste avec un échantillon de douze (12) agents et notre approche est inductive. Nous avons démontré à travers cet article qu’une bonne politique de développement des compétences doit mettre l’accent sur l’amélioration des aptitudes et la formation continue des agents

Analyse de la Distribution Spatiale des Infrastructures de Stockage et de Vente des Produits Pétroliers dans le District de Bamako

The growing demand for petroleum products in Mali has led to an increase in the construction of service stations throughout the country. Although the primary factor may be economic, the question is whether the distribution of these facilities follows a geographical logic. The objective of the study is to explore the spatial distribution patterns of oil facilities in Bamako using exploratory spatial data analysis methods and centrographic measurements. Data was collected between January and February 2020 across the whole city of Bamako using smartphones. A total of 423 infrastructures were counted, i.e. 02 depots, 203 service stations and 218 sales outlets. Most of these infrastructures are functional. The analysis also reveals the existence of a privileged direction of spatial distribution of facilities: north-west-south-east, where there is a stronger spatial agglomeration. Diffusion is more intense in the centre and south-east, where the role of spatial proximity is important. The areas of weak presence of oil installations are mainly found in the north and south of the city where the density of the road network is low. This work is a first mapping exercise of the storage and sale infrastructures of petroleum products in the city of Bamako. The results of these analyses will allow decision-makers to have not only an overview of the distribution of these infrastructures but also to make appropriate decisions for the installation of new petroleum infrastructures in Bamako.La demande croissante de produits pétroliers au Mali a conduit à l'augmentation de la construction de stations-service dans tout le pays. Même si le facteur de premier rang pourrait être économique, la question qu’on peut se poser est savoir est que la distribution de ces installations suit une logique géographique. L’objectif de l’étude est d’explorer les formes de distribution spatiale des installations pétrolières à Bamako en utilisant les méthodes d’analyse exploratoire des données spatiales et les mesures centrographiques. Les données ont été collectées entre janvier et février 2020 à travers toute la ville de Bamako à l’aide de smartphone. Un total de 423 infrastructures a été dénombré soit 02 dépôts, 203 stations-services et 218 points de vente. Majoritairement ces infrastructures sont fonctionnelles. L’analyse révèle aussi l’existence d’une direction privilégiée de la diffusion spatiale des installations : nord-ouest sud-est, où on note une plus forte agglomération spatiale. La diffusion est plus intense au centre et au sud-est, où le rôle de la proximité spatiale est important. Les zones de faible présence d’installations pétrolières se retrouvent surtout au nord et au sud de la ville où la densité du réseau routier est faible. Ce travail est une première opération de cartographie des infrastructures de stockage et de vente de produits pétroliers dans la ville de Bamako. Les résultats issus de ces analyses permettent aux décideurs d’avoir non seulement une vue d’ensemble de la distribution de ces infrastructures mais aussi pour prendre des décisions approprier pour l’installation de nouvelles infrastructure pétrolière à Bamako

Analyse de la Distribution Spatiale des Infrastructures de Stockage et de Vente des Produits Pétroliers dans le District de Bamako

The growing demand for petroleum products in Mali has led to an increase in the construction of service stations throughout the country. Although the primary factor may be economic, the question is whether the distribution of these facilities follows a geographical logic. The objective of the study is to explore the spatial distribution patterns of oil facilities in Bamako using exploratory spatial data analysis methods and centrographic measurements. Data was collected between January and February 2020 across the whole city of Bamako using smartphones. A total of 423 infrastructures were counted, i.e. 02 depots, 203 service stations and 218 sales outlets. Most of these infrastructures are functional. The analysis also reveals the existence of a privileged direction of spatial distribution of facilities: north-west-south-east, where there is a stronger spatial agglomeration. Diffusion is more intense in the centre and south-east, where the role of spatial proximity is important. The areas of weak presence of oil installations are mainly found in the north and south of the city where the density of the road network is low. This work is a first mapping exercise of the storage and sale infrastructures of petroleum products in the city of Bamako. The results of these analyses will allow decision-makers to have not only an overview of the distribution of these infrastructures but also to make appropriate decisions for the installation of new petroleum infrastructures in Bamako.La demande croissante de produits pétroliers au Mali a conduit à l'augmentation de la construction de stations-service dans tout le pays. Même si le facteur de premier rang pourrait être économique, la question qu’on peut se poser est savoir est que la distribution de ces installations suit une logique géographique. L’objectif de l’étude est d’explorer les formes de distribution spatiale des installations pétrolières à Bamako en utilisant les méthodes d’analyse exploratoire des données spatiales et les mesures centrographiques. Les données ont été collectées entre janvier et février 2020 à travers toute la ville de Bamako à l’aide de smartphone. Un total de 423 infrastructures a été dénombré soit 02 dépôts, 203 stations-services et 218 points de vente. Majoritairement ces infrastructures sont fonctionnelles. L’analyse révèle aussi l’existence d’une direction privilégiée de la diffusion spatiale des installations : nord-ouest sud-est, où on note une plus forte agglomération spatiale. La diffusion est plus intense au centre et au sud-est, où le rôle de la proximité spatiale est important. Les zones de faible présence d’installations pétrolières se retrouvent surtout au nord et au sud de la ville où la densité du réseau routier est faible. Ce travail est une première opération de cartographie des infrastructures de stockage et de vente de produits pétroliers dans la ville de Bamako. Les résultats issus de ces analyses permettent aux décideurs d’avoir non seulement une vue d’ensemble de la distribution de ces infrastructures mais aussi pour prendre des décisions approprier pour l’installation de nouvelles infrastructure pétrolière à Bamako

Logement et déterminants du bien-être objectif des ménages locataires de Bamako

This research is part of work on the link between housing and objective well-being, combining the characteristics of the utilitarian approach with those of the capabilist approach while highlighting the spatial dimension. It proposes to develop and test a method which makes it possible 1) to identify the potentially constitutive elements of objective well-being in housing and 2) to determine, based on the declared preferences of households, the most suitable housing or the less pleasant for them. Empirical analyzes have revealed to us that the type and size of the household as well as the area of ​​residence appear to be the primary constituent elements of household well-being in housing and that it is in certain peri-urban municipalities in urban centers that their well-being -being in housing would be the highest and at the lowest cost. Thus, the rent paid for accommodation varies depending on the size of the accommodation which also depends on the size of the household and its place of residence. The high cost of rent is a handicap to the objective well-being of the household because it is a burden on its income. However, when the household is well housed, it is spared from several respiratory, skin and infectious diseases. This can allow the household to save on its income in order to ensure the education and good health of its family, the basis of the well-being and development of a nation. Any government policy in the search for development must ensure the well-being of the population and therefore of households. Indeed, the consumption of housing by the household is a key factor in achieving its objective well-being.   Keywords: housing, determinants, objective well-being, tenant households, Bamako Classification JEL: I31 J12 Paper type: Empirical ResearchCette recherche s’inscrit dans les travaux sur le lien entre le logement et le bien-être objectif, alliant les caractéristiques de l’approche utilitariste à celles de l’approche capabiliste tout en mettant à l’honneur la dimension spatiale. Il se propose d’élaborer et de tester une méthode qui permet 1) d’identifier les éléments potentiellement constitutifs du bien-être objectif dans un logement et 2) de déterminer à partir des préférences déclarées des ménages, les logements les plus amènes ou les moins amènes pour eux. Les analyses empiriques nous ont révélé que le type et la taille du ménage ainsi que le milieu de résidence apparaissent comme les premiers éléments constitutifs du bien-être en logement des ménages et que c’est dans certaines communes périurbaines des pôles urbains, que leur bien-être en logement serait le plus élevé et à moindre coût. Ainsi, le loyer payé pour un logement varie en fonction de la taille du logement qui dépend également de la taille du ménage et de son lieu de résidence. Le coût élevé du loyer est un handicape au bien-être objectif du ménage, car c’est un poids sur son revenu. Cependant, lorsque le ménage est bien logé, il est épargné de plusieurs maladies respiratoires, cutanées et infectieuses. Ceci peut permettre au ménage de faire des économies sur son revenu afin d’assurer l’éducation et la bonne santé de sa famille, socle du bien-être et du développement d’une nation. Toute politique gouvernementale, dans la recherche du développement, doivent assurer le bien-être de la population, donc des ménages. En effet, la consommation de logement par le ménage est un facteur clé d’atteinte de son bien-être objectif.     Mots clés : logement, déterminants, bien-être objectif, ménages locataires, Bamako JEL Classification : I31 J12 Type du papier : Recherche empiriqu

SARS-CoV-2 infection and antibody seroprevalence in routine surveillance patients, healthcare workers and general population in Kita region, Mali: an observational study 2020–2021

Objective: To estimate the degree of SARS-CoV-2 transmission among healthcare workers (HCWs) and general population in Kita region of Mali. Design: Routine surveillance in 12 health facilities, HCWs serosurvey in five health facilities and community serosurvey in 16 villages in or near Kita town, Mali. Setting: Kita region, western Mali; local health centres around the central (regional) referral health centre. Participants: Patients in routine surveillance, HCWs in local health centres and community members of all ages in populations associated with study health centres. Main outcome measures: Seropositivity of ELISA test detecting SARS-CoV-2-specific total antibodies and real-time RT-PCR confirmed SARS-CoV-2 infection. Results: From 2392 routine surveillance samples, 68 (2.8%, 95% CI: 2.2% to 3.6%) tested positive for SARS-CoV-2 by RT-PCR. The monthly positivity rate was 0% in June–August 2020 and gradually increased to 6% by December 2020 and 6.2% by January 2021, then declined to 5.5%, 3.3%, 3.6% and 0.8% in February, March, April and May 2021, respectively. From 397 serum samples collected from 113 HCWs, 175 (44.1%, 95% CI: 39.1% to 49.1%) were positive for SARS-CoV-2 antibodies. The monthly seroprevalence was around 10% from September to November 2020 and increased to over 40% from December 2020 to May 2021. For community serosurvey in December 2020, overall seroprevalence of SARS-CoV-2 antibodies was 27.7%. The highest age-stratified seroprevalence was observed in participants aged 60–69 years (45.5%, 95% CI: 32.3% to 58.6%). The lowest was in children aged 0–9 years (14.0%, 95% CI: 7.4% to 20.6%). Conclusions: SARS-CoV-2 in rural Mali is much more widespread than assumed by national testing data and particularly in the older population and frontline HCWs. The observation is contrary to the widely expressed view, based on limited data, that COVID-19 infection rates were lower in 2020–2021 in West Africa than in other settings

Overall and Gender-Specific Effects of Intermittent Preventive Treatment of Malaria with Artemisinin-Based Combination Therapies among Schoolchildren in Mali: A Three-Group Open Label Randomized Controlled Trial.

Intermittent preventive treatment of malaria among schoolchildren (IPTsc) reduces clinical malaria, asymptomatic parasitemia, and anemia. The effects of IPTsc by gender have not been studied longitudinally. We investigated overall IPTsc efficacy and conducted a secondary analysis to explore gender-specific differences. We enrolled schoolchildren aged 6-13 years in an open-label, rolling-cohort randomized controlled trial between September 2007 and February 2013 in Kolle, Mali. Annually, schoolchildren received two full-treatment courses of sulfadoxine-pyrimethamine (SP) plus artesunate, or amodiaquine (AQ) plus artesunate, or no malaria treatment as control. We used mixed-effects generalized linear models to estimate differences in treatment outcomes across groups with interaction terms to explore gender-specific differences associated with Plasmodium falciparum infection, hemoglobin, and grade point averages (GPA) based on standardized testing. Overall, 305 students contributed 4,564 observations. Compared with the control, SP plus artesunate and AQ plus artesunate reduced the odds of P. falciparum infection (odds ratio [OR]: 0.33, 95% CI: 0.26-0.43; OR: 0.46, 95% CI: 0.36-0.59). We found strong evidence of increased mean hemoglobin concentrations (g/dL) in the SP plus artesunate group versus control (difference +0.37, 95% CI: 0.13-0.58). Collectively, schoolchildren given AQ plus artesunate had higher mean GPA (difference +0.36, 95% CI: 0.02-0.69) relative to control. Schoolgirls, compared with schoolboys, given SP plus artesunate had greater improvement in GPA (+0.50, 95% CI: -0.02 to 1.02 versus -0.27, 95% CI: -0.71 to 0.16); interaction P = 0.048, respectively. The IPTsc decreases P. falciparum infections in schoolchildren. Treatment regimens that include longer-acting drugs may be more effective at decreasing malaria-related anemia and improving educational outcomes as observed among girls in this setting

Meningococcal carriage within households in the African meningitis belt: A longitudinal pilot study.

OBJECTIVES: Carriers of Neisseria meningitidis are a key source of transmission. In the African meningitis belt, where risk of meningococcal disease is highest, a greater understanding of meningococcal carriage dynamics is needed. METHODS: We randomly selected an age-stratified sample of 400 residents from 116 households in Bamako, Mali, and collected pharyngeal swabs in May 2010. A month later, we enrolled all 202 residents of 20 of these households (6 with known carriers) and collected swabs monthly for 6 months prior to MenAfriVac vaccine introduction and returned 10 months later to collect swabs monthly for 3 months. We used standard bacteriological methods to identify N. meningitidis carriers and fit hidden Markov models to assess acquisition and clearance overall and by sex and age. RESULTS: During the cross-sectional study 5.0% of individuals (20/400) were carriers. During the longitudinal study, 73 carriage events were identified from 1422 swabs analyzed, and 16.3% of individuals (33/202) were identified as carriers at least once. The majority of isolates were non-groupable; no serogroup A carriers were identified. CONCLUSIONS: Our results suggest that the duration of carriage with any N. meningitidis averages 2.9 months and that males and children acquire and lose carriage more frequently in an urban setting in Mali. Our study informed the design of a larger study implemented in seven countries of the African meningitis belt

Effect of Adding Azithromycin to Seasonal Malaria Chemoprevention.

BACKGROUND: Mass administration of azithromycin for trachoma control led to a sustained reduction in all-cause mortality among Ethiopian children. Whether the addition of azithromycin to the monthly sulfadoxine-pyrimethamine plus amodiaquine used for seasonal malaria chemoprevention could reduce mortality and morbidity among African children was unclear. METHODS: We randomly assigned children 3 to 59 months of age, according to household, to receive either azithromycin or placebo, together with sulfadoxine-pyrimethamine plus amodiaquine, during the annual malaria-transmission season in Burkina Faso and Mali. The drug combinations were administered in four 3-day cycles, at monthly intervals, for three successive seasons. The primary end point was death or hospital admission for at least 24 hours that was not due to trauma or elective surgery. Data were recorded by means of active and passive surveillance. RESULTS: In July 2014, a total of 19,578 children were randomly assigned to receive seasonal malaria chemoprevention plus either azithromycin (9735 children) or placebo (9843 children); each year, children who reached 5 years of age exited the trial and new children were enrolled. In the intention-to-treat analysis, the overall number of deaths and hospital admissions during three malaria-transmission seasons was 250 in the azithromycin group and 238 in the placebo group (events per 1000 child-years at risk, 24.8 vs. 23.5; incidence rate ratio, 1.1; 95% confidence interval [CI], 0.88 to 1.3). Results were similar in the per-protocol analysis. The following events occurred less frequently with azithromycin than with placebo: gastrointestinal infections (1647 vs. 1985 episodes; incidence rate ratio, 0.85; 95% CI, 0.79 to 0.91), upper respiratory tract infections (4893 vs. 5763 episodes; incidence rate ratio, 0.85; 95% CI, 0.81 to 0.90), and nonmalarial febrile illnesses (1122 vs. 1424 episodes; incidence rate ratio, 0.79; 95% CI, 0.73 to 0.87). The prevalence of malaria parasitemia and incidence of adverse events were similar in the two groups. CONCLUSIONS: Among children in Burkina Faso and Mali, the addition of azithromycin to the antimalarial agents used for seasonal malaria chemoprevention did not result in a lower incidence of death or hospital admission that was not due to trauma or surgery than antimalarial agents plus placebo, although a lower disease burden was noted with azithromycin than with placebo. (Funded by the Joint Global Health Trials scheme; ClinicalTrials.gov number, NCT02211729.)