116 research outputs found

    Sustainable transfer of manual well drilling technology to the private sector: a Niger case study

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    This paper examines the benefits and shortcomings associated with the introduction of manual drilling in Niger over a 45year period. Using the experience in Niger, the paper highlights the necessary and desirable conditions under which manual drilling can become integrated into the mainstream in the water sector. As such, the paper enables practitioners who are interested in promoting manual drilling in their countries to avoid some of the pitfalls and benefit from the successes. The paper is based on the authors’ more than 30 year combined experience in promoting manual drilling in Niger

    A Maximum Power Point Tracking Control Algorithms for a PMSG‐based WECS for Isolated Applications: Critical Review

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    This chapter deals with a comprehensive overview study of the direct‐driven (DD) permanent magnet synchronous generator (PMSG) for wind‐energy generation system for stand‐alone applications. The dynamic model of PMSG is presented, and different maximum power point tracking (MPPT) algorithms have been realized in the aim to compare their performance. A comparison of performances of the conventional P&O MPPT and the fuzzy logic P&O (FLC P&O) MPPT is presented. Control technique for the presented system is presented and analyzed for the generator side converter. The simulation results carried out using Matlab/Simulink software show the effectiveness of the wind turbine control system

    Traitement de la maladie de Vogt-Koyanagi-Harada : Une revue narrative de la littérature: Treatment of Vogt-Koyanagi-Harada disease: A narrative literature review

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    Non-traumatic, exudative, bilateral panuveitis associated with extraocular manifestations, Vogt-Koyanagi-Harada disease (VKH) is an autoimmune disease mediated by Th1 lymphocytes reacting against melanocytes. It is a rare disease with female predominance. VKH disease is a diagnostic and therapeutic emergency. Treatment is based mainly on early and aggressive corticosteroid therapy to shorten the duration of the disease, prevent progression to chronicity, and reduce the incidence of extraocular manifestations. It is a corticosteroid-responsive disease, but unfortunately, relapses in the form of anterior uveitis are not rare, mainly at the time or at the end of tapering of corticosteroids. In these situations, or in case of intolerance to prolonged corticosteroid therapy, the use of conventional immunosuppressive agents or immunomodulatory drugs able to suppress the lymphocyte response is recommended. Intravenous immunoglobulins may also be used in patients with relapse or attack of the disease. In the present study, we performed a narrative literature review to summarize the different therapeutic aspects of VKH in the form of treatment algorithm. PanuvĂ©ite bilatĂ©rale non traumatique, exsudative, associĂ©e Ă  des manifestations extraoculaires, la maladie de Vogt-Koyanagi-Harada (VKH) est une maladie auto-immune mĂ©diĂ©e par les lymphocytes Th1 rĂ©agissant contre les mĂ©lanocytes. C’est une maladie rare Ă  prĂ©dominance fĂ©minine. La maladie de VKH est une urgence diagnostique et thĂ©rapeutique. Le traitement repose essentiellement sur une corticothĂ©rapie prĂ©coce et agressive avec possibilitĂ© de dĂ©gression progressive lente sur plusieurs mois, afin deraccourcir la durĂ©e de la maladie, d’empĂȘcher la progression vers la chronicitĂ©, et de rĂ©duire l’incidence des manifestations extraoculaires. C’est une maladie corticosensible, mais malheureusement des rechutes sous forme d’uvĂ©ite antĂ©rieure ne sont pas rares, principalement au moment ou en fin de dĂ©gression de la corticothĂ©rapie. Dans ces situations ou en cas d’intolĂ©rance Ă  la corticothĂ©rapie prolongĂ©e, le recours aux immunosuppresseurs conventionnels ou mĂ©dicaments immunomodulateurs capables de supprimer la rĂ©ponse lymphocytaire est de rĂšgle. Les immunoglobulines intraveineuses peuvent Ă©galement ĂȘtre proposĂ©es chez les patients prĂ©sentant une rechute ou une poussĂ©e de la maladie. Dans la prĂ©sente Ă©tude, nous rĂ©alisons une revue narrative de la littĂ©rature en dĂ©crivant les diffĂ©rents aspects thĂ©rapeutiques de la maladie de VKH afin de les rĂ©sumer sous forme d’un algorithme thĂ©rapeutique

    Ladrones merodeando por África

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    Contiene la nota "Llamamiento de Dakar contra el Acaparamiento de Tierras", de La Vía Campesina.En este artículo contamos con la voz de dos importantes dirigentes campesinos africanos, Mamadou Cissokho del Senegal e Ibrahim Coulibaly de Mali, que siempre se han distinguido por su autonomía política como por su feroz defensa de la independencia de las organizaciones campesinas. Son estandartes de la resistencia desde lo local frente a las presiones a favor del libre comercio, y saben el valor de las alianzas. En sus escritos ambos ponen atención en el preocupante y creciente fenómeno de acaparamiento de tierras en África, que ha dado lugar durante la reciente celebración del Foro Social Mundial en Dakar, a la denuncia de La Vía Campesina que se incluye como tercer texto

    Investigation dŽune épidémie de coqueluche dans le district sanitaire Tahoua département, Région de Tahoua, Niger, 2019: Etude descriptive des cas: Investigation of a pertussis epidemic in the Tahoua department health district, Tahoua region, Niger, 2019: Descriptive case study

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    Introduction: Au Niger, chaque annĂ©e des Ă©pidĂ©mies de coqueluche sont rapportĂ©es. De 2015 Ă  2019, le pays a enregistrĂ© 2184 cas suspects de coqueluche. Le 27 fĂ©vrier 2019, le CSI d'Afalla a notifiĂ© un nombre inhabituel des cas de toux quinteuse. Nous avons investiguĂ© un foyer Ă©pidĂ©mique dans le District Sanitaire (DS) Tahoua dĂ©partement en vue de confirmer, dĂ©crire les cas et de mettre en place des actions de santĂ© publique. L'objectif Ă©tait de dĂ©crire les rĂ©sultats de cette investigation. MĂ©thodes: Il s'agissait d'une Ă©tude transversale descriptive du 28 fĂ©vrier au 12 mars 2019. L'ensemble de la population du Centre de SantĂ© IntĂ©grĂ© (CSI) de Affala a Ă©tĂ© considĂ©rĂ©. Un cas probable Ă©tait toute personne rĂ©sidant dans l'aire du CSI de Affala du 17 au 12 mars 2019 prĂ©sentant une toux d'une durĂ©e ≄2 semaines, avec vomissements post-tussifs. Un questionnaire structurĂ© a Ă©tĂ© administrĂ© aux malades ou aux mĂšres ou accompagnants des nourrissons. Une revue documentaire et une recherche active des cas ont Ă©tĂ© rĂ©alisĂ©es. RĂ©sultats: Au total, 108 cas de coqueluche ont Ă©tĂ© enregistrĂ©s. Aucun dĂ©cĂšs n'a Ă©tĂ© notifiĂ©. Le sexe masculin reprĂ©sentait 60,2% des cas. L'Ăąge mĂ©dian Ă©tait de 7 ans intervalle interquartile IIQ (2-14 ans). Parmi les cas, 17(15,7%) Ă©taient ĂągĂ©s de moins de 5 ans. Deux villages du CSI Affala ont enregistrĂ© des cas. Tous les enfants prĂ©sentaient une toux et 14,8% des cas Ă©taient vaccinĂ©s. La durĂ©e de l'Ă©pidĂ©mie Ă©tait de 14 jours. Conclusion: L' investigation de cette Ă©pidĂ©mie a permis de dĂ©crire les cas et mettre en place des mesures de contrĂŽle et de prĂ©vention. La vaccination de routine contre la coqueluche devrait ĂȘtre renforcĂ©e. Introduction: In Niger, every year outbreaks of pertussis are reported. From 2015 to 2019, the country has recorded 2184 suspected cases of pertussis. On 27 February 2019, the Afalla IHC reported an unusual number of cases of whooping cough. We investigated an outbreak in the Tahoua Health District (HD) department in order to confirm and describe the cases and to implement public health actions. The objective was to describe the results of this investigation. Methods: This was a descriptive cross-sectional study from 28 February to 12 March 2019. The entire population of the Affala Integrated Health Centre (IHC) was considered. A probable case was any person residing in the Affala IHC area from 17 to 12 March 2019 presenting with a cough lasting ≄2 weeks, with post-cough vomiting. A structured questionnaire was administered to the patients or mothers/caregivers of infants. A literature review and active case finding were performed. Result: In total, 108 cases of pertussis were recorded. No deaths were reported. Males accounted for 60.2% of the cases. The median age was 7 years, interquartile range IIQ (2-14 years). Of the cases, 17 (15.7%) were under 5 years of age. Two villages in Affala IHC had cases. All children had a cough and 14.8% of cases were vaccinated. The duration of the epidemic was 14 days. Conclusion: The investigation of this epidemic allowed us to describe the cases and to put in place control and prevention measures. Routine vaccination against pertussis should be reinforced

    Les usages autour des mares de Falki et Chiya dans le bassin versant Zermou, région de Zinder au Niger

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    Le bassin versant Zermou fait partie du bassin de la Korama. Cette zone oĂč dominent l’agriculture et l’élevage connaĂźt une frĂ©quence des dĂ©ficits alimentaires. Depuis des dĂ©cennies, des politiques se sont intĂ©ressĂ©es Ă  amĂ©liorer et Ă  prĂ©server la situation socio-Ă©conomique des mĂ©nages ruraux. Le prĂ©sent travail vise Ă  identifier les principaux usages (maraĂźchage, Ă©levage, pĂȘche et artisanat) autour de la mare de Falki et Chiya (partie aval du bassin). La mĂ©thodologie assignĂ©e Ă  ce travail est axĂ©e autour de deux points essentiels : la recherche documentaire et les travaux de terrain. La cartographie du bassin versant est assurĂ©e Ă  l’aide des images Google Earth, 2016. Les informations ainsi recueillies ont Ă©tĂ© collectĂ©es Ă  l’aide des outils tels que le questionnaire d’enquĂȘte oĂč un Ă©chantillonnage alĂ©atoire a Ă©tĂ© fait et 75 exploitants ont Ă©tĂ© choisis suivant l’activitĂ© principale et le guide d’entretien adressĂ© aux membres de l’association d’usagers de l’eau Hadin Kai de Falki et ceux de Chiya. L’analyse des informations ainsi recueillies permet de comprendre que les activitĂ©s agricoles ; bien que certains producteurs soient exposĂ©s au manque d’équipements contribuent Ă  l’amĂ©lioration des conditions de vie et Ă  la sĂ©curitĂ© alimentaire des producteurs

    Dynamique Hydro-Erosive Actuelle Des Bassins Versants Endoreiques De La Region De Niamey (Sud-Ouest Du Niger)

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    La gĂ©nĂ©ralisation du ravinement et la baisse de la productivitĂ© des terres sont quelques-unes des principales contraintes qui assaillent l’utilisation des sols au Sahel. Pour gĂ©rer efficacement ces sols, une Ă©valuation des processus hydro-Ă©rosifs est nĂ©cessaire. Ce travail a ainsi pour objectif d’analyser la dynamique hydro-Ă©rosive sur un site expĂ©rimental installĂ© depuis 2004 dans la rĂ©gion de Niamey (Niger). Sur ce site, le dispositif de mesure est composĂ© de huit parcelles de mesures de ruissellement et d’érosion, des stations hydromĂ©triques Ă  l’exutoire des deux bassins versants endorĂ©iques et de plusieurs piquets destinĂ©s aux suivis morpho-dynamiques des ravines. AprĂšs une dĂ©cennie d’observation, les ruissellements mesurĂ©s sur les parcelles se caractĂ©risent par une dynamique saisonniĂšre croissante sur les surfaces encroĂ»tĂ©es (croĂ»tes biologique et d’érosion) et dĂ©croissante sur les surfaces cultivĂ©es. Le coefficient de ruissellement varie de 5 % sur la surface cultivĂ©e Ă  58 % sur la croĂ»te d’érosion. Au cours des 10 annĂ©es de mesure, ce coefficient a connu une forte croissance en particulier sur la jachĂšre (+ 80 %) et sur la surface cultivĂ©e (+ 300 %), traduisant ainsi la dĂ©gradation des sols. A l’échelle des bassins versants, l’augmentation du coefficient de ruissellement s’accompagne d’une Ă©rosion arĂ©olaire qui dĂ©cape le sol Ă  une vitesse moyenne de 5 mm/an et d’une Ă©rosion linĂ©aire active, de l’ordre de 4 m3/an au niveau des ravines suivies. Les transferts sĂ©dimentaires qui en rĂ©sultent agissent sur le fonctionnement morpho-sĂ©dimentaire des cours d’eau. Des amĂ©nagements antiĂ©rosifs sont nĂ©cessaires pour dissiper les processus hydro-Ă©rosifs et prĂ©server les services Ă©cosystĂ©miques des sols des bassins. Widespread gullying and the declining land productivity are some of the main constraints plaguing land use in the Sahel. In order to effectively manage these soils, it has become necessary to assess the hydro-erosive processes. The current study, thus, aims at analyzing the hydro-erosion dynamics on an experimental site installed since 2004 in the Niamey region (Niger Republic). On this site, the measurement device is made up of eight runoff and erosion measurement plots, hydrometric stations at the outlet of the two endorheic watersheds and several stakes intended for morpho-dynamic monitoring of the gullies. After a decade of observation, the runoff measured on the plots is characterized by an increasing seasonal dynamic on encrusted surfaces (biological and erosion crusts) and a decreasing one on cultivated surfaces. The runoff coefficient varies from 5% on the cultivated area to 58% on the erosion crust. Over the 10 years of measurement, this coefficient has greatly increased, especially on the fallow (+ 80%) and on cultivated area (+ 300%); this increase consequently reflects soil degradation. At the watershed scale, the increase in the runoff coefficient is accompanied by area erosion (or the erosion of the area out of the basin) which strikes the soil at an average speed of 5 mm/year and active linear erosion measuring 4 m3/year as observed at the monitored (the ongoing investigated) gullies. The resulting sediment transfers act on the morpho-sedimentary functioning of rivers. Anti-erosion facilities are necessary to dissipate the hydro-erosive processes and preserve the ecosystem services of the soil in the basin

    Epidémies de Choléra en Afrique Sub-Saharienne: Revue documentaire de 2010 à 2016

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    Introduction: Cholera remains a major public health problem in many parts of the world and particularly in sub-Saharan African countries. The objective of this study is to review data on cholera epidemiology, risk, microbiological and disease control factors in sub-Saharan Africa from 2010 to 2016. Material and method: A literature review on cholera epidemics in sub-Saharan Africa from 2010 to 2016 was conducted using electronic databases from countries that have experienced epidemics. Annual cholera data for countries with outbreaks from 2010 to 2016 have been reported. Results: From 2010 through 2016, 35 of the 54 African countries have experienced cholera epidemics. An overall of 1268 outbreaks have been reported, of which 13.04% were recorded in Nigeria and 4.35% in Burundi. The number of cases reported was 801022 and 13232 deaths (overall CFR =1.65%). Vibrio cholerae O1 and O139 are the main etiological agents. The main risk factors are heavy rains, floods, contamination of water sources and lack ofsanitation. Conclusion: In addition to the suffering of patients, cholera outbreaks cause panic, disrupt economic and social structures and hinder the development of affected communities. Mobilization of the water, sanitation and hygiene sectors is essential to ensure the benefits of patient care and cholera vaccination.Introduction : Le cholĂ©ra demeure un problĂšme majeur de SantĂ© Publique dans de nombreuses parties du monde et en particulier dans les pays d’Afrique subsaharienne. L’objectif de cette Ă©tude de faire une revue des donnĂ©essur les Ă©pidĂ©mies de cholĂ©ra, les facteurs de risques, microbiologiques et de lutte contre la maladie en Afrique sub-saharienne de 2010 Ă  2016. Materiels et mĂ©thode: Une revue de la littĂ©rature sur les Ă©pidĂ©mies de cholĂ©ra en Afrique sub-saharienne de 2010 Ă  2016 a Ă©tĂ© conduite dans des banques de donnĂ©es ou bases de donnĂ©es et bibiothĂšques Ă©lectroniques des pays ayant connu des Ă©pidĂ©mies. Les donnĂ©es annuelles de cholĂ©ra dans les pays ayant connu des Ă©pidĂ©mies de 2010 Ă  2016 ont Ă©tĂ© rapportĂ©es. RĂ©sultats : Entre 2010 et 2016, 35 des 54 pays d'Afrique ont connu des Ă©pidĂ©mies de cholĂ©ra. 1268 Ă©pisodes Ă©pidĂ©miques ont Ă©tĂ© rapportĂ©s dont 13,04% au Nigeria et 4,35% au Burundi. Le nombre de cas notifiĂ©s Ă©tait de 801022 dont 13232 dĂ©cĂšs (lĂ©talitĂ© globale =1,65%). Le Vibrio cholerae O1 et O139 sont les principaux agents Ă©tiologiques Ă©pidĂ©miogĂšnes. Les principaux facteurs de risques sont les pluies abondantes, les inondations, la contamination des sources d’eau et le manque d’assainissement. Conclusion : En dehors des souffrances Ă©prouvĂ©es par les malades, les flambĂ©es de cholĂ©ra provoquent la panique, dĂ©sorganisent les structures Ă©conomiques et sociales et freinent le dĂ©veloppement des communautĂ©s touchĂ©es. Cependant, la mobilisation des secteurs de l’eau, de l’assainissement et de l’hygiĂšne ainsi que le rensforcement des systemes de surveillance et riposte surtout au niveau transfrontalier sont des etapes essentielles pour la lutte contre les epidemies de cholera en Afrique subsaharienne

    Current status of schistosomiasis and soil-transmitted helminthiasis in Beyla and Macenta Prefectures, Forest Guinea

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    A cross-sectional survey was undertaken in children aged 9-14 years in Beyla and Macenta Prefectures, Forest Guinea. Stool samples were examined by Kato-Katz and urine samples were examined by the centrifugation method. The overall prevalence and intensity of infection was 66.2% and 462.4 eggs per gram of faeces (epg) for Schistosoma mansoni, 21.0% and 17.8 eggs per 10ml of urine for S. haematobium, 51.2% and 507.5 epg for hookworm, 8.1% and 89.1 epg for Ascaris lumbricoides and 2.4% and 16.7 epg for Trichuris trichiura. The overall prevalence of schistosomiasis (S. mansoni and/or S. haematobium) was 70.7%. The prevalence of schistosomiasis was similar to those reported in the 1990s in the region; however, the prevalence of soil-transmitted helminths has since fallen. These findings illustrate the need for schistosomiasis control in Guine

    Spatial dynamic of mobile dunes, soil crusting and Yobe’s bank retreat in the Niger’s Lake Chad basin part: Cases of Issari and Bagara

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    The process of desertification is accelerated in the northern part of Lake Chad basin since the early 1970. Those processes linked to the recurrent drought and a heavy human pressure induced a great environmental damages. So this study based on diachronic cartography (1957, 1975 and 2007) aimed to describe and quantify the degradation dynamics in the contrasting Niger’s Lake Chad basin part. Thus significant environmental changes have been observed in this area from 1957 to 2007. Indeed in the Manga, the natural commodities and fields were threatened by mobile dunes making blocking with sand: the mobile dunes spread from ~200 ha in 1975 to ~900 ha in 2007 while they had not watched in 1957. In the fluvio-deltaic area of Kadzell, the soil crusting and the Yobe River retreat remain the major damages. The crusting area has been multiplied by more than two while the lateral migration of the Yobe bank reached near of 3 m.yr-1. This study highlights the key role of man in the process of degradation related to climate parametersKey words: Lake Chad, degradation dynamics, soil crusting, dunes, human activities
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