Caractérisation Physico-Chimique Et Minéralogique Des Argiles De La Carrière De Mirriah, Région De Zinder, Utilisées Dans La Poterie

In order to contribute to the valuation of clay materials from the Zinder Region, the clays taken from the quarry and used for the pottery of Mirriah have been characterized from a physico-chemical and mineralogical point of view. So the five samples were taken and the composite sample representative of the quarry were subjected to chemical and mineralogical analyzes.The chemical analysis showed that the six samples all consisted of more than 60% aluminosilicates with a high silica/alumina ratio estimated at 2.5 on average. This report shows that the samples of this study are rich in clay minerals; this is in agreement with the estimate of the fine or clay fraction which is 39.5% of the initial mass of the raw sample. This chemical analysis also made it European Scientific Journal, ESJ ISSN: 1857-7881 (Print) e - ISSN 1857-7431 January 2021 edition Vol.17, No.3 www.eujournal.org 122 possible to highlight, at the level of these Mirriah clays, a significant iron oxide content of 32%, which gives them a brick red color. The main mineralogical phases detected by X-ray diffraction in the raw sample and its fine fraction are kaolinite, a mica structure close to illite and quartz, all weathering products of granite. This characterization indicates that the clays mined at the Mirriah quarry are very favorable materials for formulations of pottery products. Dans le but de contribuer à la valorisation des matériaux argileux de la Région de Zinder, les argiles prélevées à la carrière et utilisées pour la poterie de Mirriah ont été caractérisées du point de vue physico-chimique et minéralogique. Ainsi les cinq échantillons ont été prélevés et l’échantillon composite représentatif de la carrière, ont été soumis à des analyses chimiques et minéralogiques. Il ressort de l’analyse chimique que les six échantillons sont tous constitués à plus de 60 % d’aluminosilicates avec un rapport silice/alumine élevé estimé à 2,5 en moyenne. Ce rapport montre que les échantillons de cette étude sont riches en minéraux argileux ceci est en accord avec l’estimation de la fraction fine ou argileuse qui est de 39,5 % de la masse initiale de l’échantillon brut. Cette analyse chimique a aussi permis de mettre European Scientific Journal, ESJ ISSN: 1857-7881 (Print) e - ISSN 1857-7431 January 2021 edition Vol.17, No.3 www.eujournal.org 121 en évidence, au niveau de ces argiles de Mirriah, une teneur importante en oxyde de fer de 32% ceci leur induit une couleur rouge brique. Les phases minéralogiques principales détectées par diffraction des rayons X dans l’échantillon brut et sa fraction fine sont de la kaolinite, une structure de mica proche de l’illite et du quartz, tous des produits d’altération du granite. Cette caractérisation indique que les argiles exploitées à la carrière de Mirriah sont des matériaux très favorables aux formulations des produits de poterie

Présentations inhabituelles d’un syndrome de Plummer-Vinson chez l’africain de race noire: à propos de deux observations

Le syndrome de Plummer Vinson (SPV) est une affection rare caractérisée par une dysphagie cervicale  associée à une anémie ferriprive et un anneau sur l’oesophage supérieur. Parfois, son mode de   présentation inhabituelle peut faire errer le diagnostic. Le rétrécissement annulaire peut être de découverte fortuite lors d’une endoscopie digestive haute. Nous rapportons deux observations de  syndrome de Plummer-Vinson chez des sujets de genre masculin et féminin. Celles-ci ont comme point  commun une découverte fortuite lors d’une endoscopie digestive haute. La première observation   concernait un garçon de 14 ans aux antécédents de brûlure caustique de l’oesophage dans l’enfance avec  dysphagie haute passagère ne l’inquiétant pas depuis lors. Il était reçu en urgence pour une endoscopie  digestive haute motivée par une dysphagie de survenue brutale secondaire à une prise d’aliment solide.  L’examen clinique avait objectivé une chéilite angulaire. La biologie montrait un abaissement de la  ferritinémie sans anémie. L’endoscopie avait mis en évidence un anneau circulaire franchi avec ressaut au niveau de la bouche de Killian. Elle avait également permis l’extraction d’un corps étranger à type de noyau de « pain de singe » mais la lumière de l’oesophage était infranchissable à partir du niveau d’arrêt. Le transit oesophagien montrait un ralentissement du produit de contraste au niveau de l’sophage cervical et thoracique sans lésions morphologiques. Dans la deuxième observation, il s’agissait d’une jeune femme de 35 ans adressée à l unité d’endoscopie digestive pour objectiver une gastrite atrophique sur une suspicion de la maladie de Biermer. La fibroscopie mettait alors en évidence, un rétrécissement annulaire infranchissable à 18 centimètres des arcades dentaires. La biologie montrait une anémie avec   augmentation de la ferritinémie. Dans les deux cas, le traitement martial était systématique associé à des séances de dilatation aux bougies de Savary-Gilliar. L’évolution à court terme était favorable avec une amélioration de la dysphagie et une correction des anomalies biologiques. La dysphagie passagère peut  faire errer le diagnostic d’un syndrome de Plummer-Vinson. Son association soit avec une sténose  caustique de l sophage soit avec une maladie de Biermer est possible. Le risque de dégénérescence accru devrait motiver une surveillance rapprochée.Key words: Plummer Vinson, dysphagie, brulure caustique, maladie de Bierme

An integrated, probabilistic model for improved seasonal forecasting of agricultural crop yield under environmental uncertainty

We present a novel forecasting method for generating agricultural crop yield forecasts at the seasonal and regional-scale, integrating agroclimate variables and remotely-sensed indices. The method devises a multivariate statistical model to compute bias and uncertainty in forecasted yield at the Census of Agricultural Region (CAR) scale across the Canadian Prairies. The method uses robust variable-selection to select the best predictors within spatial subregions. Markov-Chain Monte Carlo (MCMC) simulation and random forest-tree machine learning techniques are then integrated to generate sequential forecasts through the growing season. Cross-validation of the model was performed by hindcasting/backcasting and comparing forecasts against available historical data (1987–2011) for spring wheat (Triticum aestivum L.). The model was also validated for the 2012 growing season by comparing forecast skill at the CAR, provincial and Canadian Prairie region scales against available statistical survey data. Mean percent departures between wheat yield forecasted were under-estimated by 1–4% in mid-season and over-estimated by 1% at the end of the growing season. This integrated methodology offers a consistent, generalizable approach for sequentially forecasting crop yield at the regional-scale. It provides a statistically robust, yet flexible way to concurrently adjust to data-rich and data-sparse situations, adaptively select different predictors of yield to changing levels of environmental uncertainty, and to update forecasts sequentially so as to incorporate new data as it becomes available. This integrated method also provides additional statistical support for assessing the accuracy and reliability of model-based crop yield forecasts in time and space

Електричні властивості двошарових плівок окислів металів

Досліджені газочутливі властивості тонких двошарових плівок окислів металів, в яких нижній шар є крупнокристалічним, а верхній має високодисперсну структуру. Розглядаються фізичні основи і технологічні прийоми одержання таких плівок вакуумним методом. Двошарові плівки виявляють кращу чутливість до відновлюючих домішок у повітрі, ніж одношарові

Health facility-based prevalence and potential risk factors of autism spectrum disorders in Mali

Background: The prevalence of autism spectrum disorders (ASD) is 1-2% worldwide, 1 in 68 in the U.S, and unknown in Africa. ASD is under-diagnosed in Mali due to stigma and the lack of appropriate human resources and infrastructure.Objective: To determine the ASD frequency and potential risk factors in Mali.Methods: We identified all the health facilities and community-based organizations involved in the ASD diagnosis and management in Bamako. We established an ASD research and awareness platform in Mali, which encompasses community-based organizations and a multidisciplinary team including psychiatrists, psychologists, pediatricians, geneticists, and public health and social science specialists. Through this platform, we performed a survey in health facilities and organizations where patients with ASD are likely to seek care in Bamako. We reviewed the psychiatric patient registry to obtain basic epidemiological profiles of children with ASD, epilepsy and other psychiatric disorders.Results: We found a health facility-based prevalence of ASD of 4.5% (105/2,343) in Bamako. The mean age at the first outpatient visit was 7.64 ± 3.85 years old. First degree consanguinity of 29.5% (31/105) was more frequent in parents of ASD children versus age and sex matched controls OR= 4.37 [1.96-9.76] p=0.0001.Conclusion: Our data suggest that ASD is more common than expected in Mali. The established ASD awareness and research platform may improve the diagnosis and management of ASD by raising ASD awareness, training of Malian clinicians and researchers in early ASD screening and diagnosis, and strengthening research capacity in genomics of ASD and other mental disorders.Keywords: ASD, prevalence, consanguinity, health facilit

[Prevention of liver fibrosis and liver cancer linked to hepatitis B virus in Africa: the Prolifica study].

Despite the existence of an effective vaccine, HBV infects 257 million people worldwide and is the cause of the majority of HCC. With an annual mortality rate of 887 000 patients in 2015, this cancer is the second deadliest. Low-income countries such as ones in sub-Saharan Africa are the most at risk due to the limited access to healthcare. To overcome this and born from an international research collaboration within an EU project, the Prolifica study aimed at evaluating a screen-and-treat program to prevent HBV complications, and more particularly HCC. Based on communities, facilities and hospitals HBsAg+ detection, the study lasted from 2011 to 2016. From the "cost effectiveness" feasibility of such a program to the development of simple scores for antiviral treatment, Prolifica uncovered data of crucial importance in a region with low HBV infection awareness, transmissions modes and prevention means which could have impacts on public health policies

HBV continuum of care using community- and hospital-based screening interventions in Senegal: Results from the PROLIFICA programme

BACKGROUND & AIMS: Strategies to implement HBV screening and treatment are critical to achieve HBV elimination but have been inadequately evaluated in sub-Saharan Africa (sSA). METHODS: We assessed the feasibility of screen-and-treat interventions in 3 real-world settings (community, workplace, and hospital) in Senegal. Adult participants were screened using a rapid HBsAg point-of-care test. The proportion linked to care, the proportion who had complete clinical staging (alanine transaminase [ALT], viral load, and FibroScan®), and the proportion eligible for treatment were compared among the 3 intervention groups. RESULTS: In 2013-2016, a total of 3,665 individuals were screened for HBsAg in the community (n = 2,153) and in workplaces (n = 1,512); 199/2,153 (9.2%) and 167/1,512 (11%) were HBsAg-positive in the community and workplaces, respectively. In the hospital setting (outpatient clinics), 638 HBsAg-positive participants were enrolled in the study. All infected participants were treatment naïve. Linkage to care was similar among community-based (69.9%), workplace-based (69.5%), and hospital-based interventions (72.6%, p = 0.617). Of HBV-infected participants successfully linked to care, full clinical staging was obtained in 47.5% (66/139), 59.5% (69/116), and 71.1% (329/463) from the community, workplaces, and hospitals, respectively (p <0.001). The proportion eligible for treatment (EASL criteria) differed among community- (9.1%), workplace- (30.4%), and hospital-based settings (17.6%, p = 0.007). Acceptability of antiviral therapy, adherence, and safety at 1 year were very good. CONCLUSIONS: HBV screen-and-treat interventions are feasible in non-hospital and hospital settings in Senegal. However, the continuum of care is suboptimal owing to limited access to full clinical staging. Improvement in access to diagnostic services is urgently needed in sSA. LAY SUMMARY: Hepatitis B infection is highly endemic in Senegal. Screening for infection can be done outside hospitals, in communities or workplaces. However, the hepatitis B continuum of care is suboptimal in Senegal and needs to be simplified to scale-up diagnosis and treatment coverage

Prevention of Liver Fibrosis and Cancer in Africa: The PROLIFICA project – a collaborative study of hepatitis B-related liver disease in West Africa

Hepatitis B virus (HBV) infection causes a spectrum of acute and chronic liver disease ranging from inactive chronic carrier status to progressive chronic hepatitis, culminating in end-stage cirrhosis and liver cancer. In sub-Saharan Africa, HBV infection is endemic and the HBV-related disease burden is high, making HBV a signficant threat to health in the African continent. The European Union-funded Prevention of Liver Fibrosis and Cancer in Africa (PROLIFICA) project was established in 2011, with the central directive to reduce the incidence of HBV-related liver cancer in West Africa. In this editorial, we outline some of the achievements and challenges of the PROLIFICA platform in West Africa, highlighting the the importance of collaborative studies in Africa

African AIDS Vaccine Programme for a Coordinated and Collaborative Vaccine Development Effort on the Continent

The African AIDS Vaccine Programme, formed in 2000, is a network of African HIV vaccine stakeholders, led by Africans across the continent, with a vision of an African continent without AIDS

Détermination du débit de filtration glomérulaire au cours de la drépanocytose au Sénégal: Schwartz, Cockcroft et Gault, MDRD, CKD-EPI ou JSCCS ?

La détermination du Débit de Filtration Glomérulaire (DFG) est importante chez les drépanocytaires du fait qu’ils constituent un groupe de patients chez lesquels des atteintes rénales sont fréquemment décrites notamment l’hyperfiltration glomérulaire. Dès lors, à une époque où les calculateurs en ligne proposent simultanément différentes formules de détermination du DFG, il serait important d’évaluer au sein d’une population noire africaine drépanocytaire l’équivalence entre ces formules qui ont été développées et validées sur des populations caucasiennes et afro-américaines à DFG normal ou diminué. Ainsi cette étude avait pour but d’évaluer l’interchangeabilité des différentes formules de détermination du DFG en les appliquant à des drépanocytaires. Des enfants et adultes sénégalais drépanocytaires homozygotes ont été alors recrutés et leur DFG calculé. La fréquence de l’hyperfiltration glomérulaire et celle de l’insuffisance rénale ont été calculées à partir des résultats obtenus avec les formules de Schwartz et du CKD-EPI. La concordance des différentes formules a été évaluée avec la méthode Bland-Altman. Au total 56 adultes et 62 enfants ont été inclus dans l’étude. L’insuffisance rénale a été notée chez 1,78% des adultes et 9,68% des enfants ; l’hyperfiltration glomérulaire chez 66,10% des adultes et 25,8% des enfants. Par rapport aux formules de référence (CKD-EPI, Schwartz), tous les biais relevés étaient significativement différents de zéro à l’exception de celui de Cockcroftet Gault qui était statistiquement nul. Les limites de concordance étaient toutes inacceptablement larges par rapport aux limites attendues à l’exception de celles du CKD-EPI sans ajustement sur la race. Ainsi, la formule de Schwartz n’était pas interchangeable avec celle du JSCCS chez les enfants, tout comme celle du CKD-EPI ne l’était pas non plus avec celles du JSCCS, de Cockcroft, du MDRD ou du CKD-EPI sans ajustement sur la race chez les adultes drépanocytaires. &nbsp; English title: Determination of glomerular filtration rate in sickle cell disease in Senegal: Schwartz, Cockcroft and Gault, MDRD, CKD-EPI or JSCCS? Determination of Glomerular Filtration Rate (GFR) is important in patients living with sickle cell disease (SCD) because they constitute a group of patients where kidney dysfunction is frequently described, in particular glomerular hyperfiltration. Therefore, at a time when online calculators simultaneously propose different formulas to estimate GFR, it would be important to evaluate in a black African population living with SCD the equivalence between these formulas which have been developed and validated on Caucasian and African American populations with normal or decreased GFR. Thus, the aim of this study was to evaluate interchangeability of different GFR formulas in a group of patients living with SCD. Homozygous Senegalese sickle cell children and adults were then recruited and their GFR computed using Schwartz and JSCCS in children, Cockcroft and Gault, CKD-EPI with and without adjustment for ethnicity, MDRD and JSCCS formulas in adults. The frequency of glomerular hyperfiltration and renal failure was computed based on the results generated using Schwartz and CKD-EPI formulas. The agreement between formulas was assessed with BlandAltman method. A total of 56 adults and 62 children were included in this study. Renal failure was observed in 1.78% of adults and 9.68% of children; glomerular hyperfiltration in 66.10% of adults and 25.8% of children. Compared with reference formulas (CKD-EPI, Schwartz), all biases found were significantly different from zero except for Cockcroft and Gault formula bias, which was statistically zero. The limits of agreement were all unacceptably wide compared with the expected limits with the exception of CKD-EPI without adjustment for ethnicity. Thus, Schwartz formula would not be interchangeable with JSCCS formula in children, nor was the CKD-EPI formula interchangeable with the JSCCS, Cockcroft and Gault, MDRD or CKD-EPI without adjustment for ethnicity formulas in adults living with sickle cell anemia