3d Approach Of Spectral Response For A Bifacial Silicon Solar Cell Under A Constant Magnetic Field

A three-dimensional study is made to improve the theoretical approach of spectral response of bifacial polycrystalline silicon solar cells. This study has allowed taking into account new parameters like grain size and grain boundaries recombination velocity, which reduce the cell efficiency. Losses in emitter region and external magnetic field are also being taken into account in order to perfect the description of measured spectral response. Then the new analytical expressions of carrier, photocurrent and short circuit densities are produced for front side and rear side illuminations. Homemade software based on the new analytical expressions of internal quantum efficiency is used to fit the experimental data

A randomised trial in Mali of the effectiveness of weekly iron supplements given by teachers on the haemoglobin concentrations of schoolchildren

Objective: To assess the effect on the haemoglobin concentrations of schoolchildren of weekly iron tablets administered by teachers. Design: Sixty schools were randomly assigned to two groups: in 30 schools children were given weekly for 10 weeks a tablet providing 65 mg of iron and 0.25 mg of folic acid; in the other 30 schools no iron tablets were given. All children were dewormed and given vitamin A before the study began. The haemoglobin concentration of up to 20 randomly selected children in each school was estimated before and 2 weeks after the end of treatment. Setting: Rural community schools in Kolondieba district of Mali. Subjects: Some 1113 schoolchildren aged 6-19 years with a mean of 11.4 years. Results: The haemoglobin concentration of treated children rose on average by 1.8 g l -1 (P < 0.001) and the prevalence of anaemia fell by 8.2% (P < 0.001); in untreated children the haemoglobin concentration fell by an average of 22.7 g l -1 (P < 0.001) and the prevalence of anaemia rose by 9.4% (P < 0:001). The fall in haemoglobin concentration among untreated girls of 24.0 g l21 was greater than in untreated boys (20.3 g l -1 (P < 0.001). Conclusions: Weekly iron tablets given by teachers prevented a general fall in the haemoglobin concentrations of untreated children, and led to a small but statistically significant rise among treated children (P < 0.001). Young children benefited more than children aged </=12 years, and girls benefited more than boys

The WHO five keys to safer food: A tool for food safety health promotion

Foodborne diseases continue to be significant causes of morbidity and mortality within the African Region. Many cases of foodborne disease occur due to basic errors in food preparation or handling either in food service establishments or at home. Educating food handlers, including consumers, therefore, can significantly reduce the chances of contracting food-borne illnesses and the effects of outbreaks, as well as improve public health. Food safety education programmes need to particularly target certain segments of the population who, either directly have a role in food preparation and/or have increased vulnerability to foodborne diseases. In response to the increasing need to educate food handlers, including consumers about their responsibilities for assuring the safety of food, the World Health Organization (WHO) initiated a health promotion campaign around five simple rules, "the five keys to safer food" to help ensure food safety during food handling and preparation. The core messages of the WHO five keys to safer food are: keep clean; separate raw and cooked; cook thoroughly; keep food at safe temperatures; and use safe water and raw materials. These messages have been adapted to different target audiences and settings such as healthy food markets; emergency situations such as prevention of outbreaks; food safety for travellers; preparation of mass gathering events; streetvended foods; training of women; and growing of safer fruits and vegetables. Educational projects targeting different types of food handlers, high-risk groups andsettings are being implemented in several countries in the African Region. This article discusses how the WHO five keys to safer food have been used as a tool for food safety education. Experiences of selected countries in the African Region in the promotion of the WHO five keys to safer food in different settings are presented. It further discusses opportunities and future perspectives in the promotion of the WHO five keys to safer food in the African Region

Developing and maintaining national food safety control systems: Experiences from the WHO African region

The establishment of effective food safety systems is pivotal to ensuring the safety of the national food supply as well as food products for regional and international trade. The development, structure and implementation of modern food safety systems have been driven over the years by a number of developments. These developments include: a reorientation of quality assurance protocols; emphasis on the development of integrated and holistic food safety systems with a farm-to-table approach; increasedrecognition of the respective roles of the different stakeholders along the food chain; increased food trade coupled with obligations under trade agreements; and advances in the control of foodborne hazards. At its core, a modern food safety system includes enabling food laws, policies, regulations and standards; mechanisms for coordination; operational food inspection and laboratory services as well as national information,education and communication programmes. While progress has been made in some countries in the WHO African Region at modernizing their food safety systems, many others are still grappling with the basics for development of effective food control systems. The traditional food control systems in a number of African countries do not provide the concerned agencies with a clear mandate and authority to prevent food safety problems. Effective food control in a number of these countries is undermined by a number of challenges including limited awareness about food safety, inadequate enabling policy, outdated legislation and regulations; inadequate coordination; and inadequate capacity and resources for food safety. This paper reviews the components of a modern national food safety control system and examines efforts at strengthening national food safety control systems in the African Region. It includesexperiences from countries that have made efforts at strengthening their national food safety control systems in view of current developments. The paper further discusses some of the challenges of food control systems in the Region and prospects for improvements. It concludes by suggesting the way forward for improving national food safety control systems in the Region

L’epilepsie en milieu scolaire : enquete chez les enseignants de la ville de Kati au Mali et revue de la litterature

Introduction La prévalence de l’épilepsie en Afrique subsaharienne est élevée. Nous avons mené une étude transversale et descriptive dans l’ensemble des écoles primaires de la ville de Kati (200 000 habitants). Les enseignants furent interviewés de manière exhaustive à l’aide de questionnaires portant, d’une part, sur les connaissances, attitudes et pratiques des enseignants en matière d’épilepsie et, d’autre part, sur leurs avis sur les conséquences psychologiques, sociales pour l’enfant épileptique et les incidences sur sa scolarité.Résultats Nous avons interrogé 92 enseignants (60 hommes et 32 femmes). L’âge moyen des enseignants était de 30 ans. La majorité d’entre eux avait une expérience professionnelle de plus de 5 ans. Environ 38% des enseignants attribuaient la maladie à une cause surnaturelle. Plus de 39% des enseignants pensaient que l’épilepsie était contagieuse et 61% pensaient que l’épilepsie était incurable. 79% interdisaient systématiquement la pratique du sport à l’enfant épileptique. Environ 55% pensaient que l’enfant épileptique avait des capacités cognitives inférieures à celles de l’enfant non épileptique et 88% affirmaient que l’enfant épileptique était incapable d’avoir une scolarité normale. 59% trouvaient que l’élève épileptique était victime de stigmatisation et de marginalisation. Devant une crise, 68% renvoyaient l’enfant au domicile.Conclusion Ce travail fait apparaître un besoin de formation des enseignants en matière d’épilepsie. Les données actuelles sur la fréquence de l’épilepsie en milieu scolaire justifient une attention particulière des services de santé et de ceux de l’éducation nationale sur la scolarisation de l’enfant épileptique.Mots clés : Epilepsie, Ecole, Enseignants, Mali, Pratiques

Responding to the changing WASH needs in Mali

The political unrest that started in Mali on the 21st of March 2012 has had a significant impact on access to safe water and sanitation for an estimated 1.9 million people. Like most development or non-humanitarian organisations, WaterAid Mali was forced to stop their water and sanitation interventions in northern target communities due to insecurity. In the south, water, sanitation and hygiene needs changed quickly, as a result of the large number of people migrating from the north. WaterAid Mali has adapted to these changes through reallocating resources, implementing new activities and internal capacity building. This paper will discuss the experiences of WaterAid Mali as well as the lessons learnt

Contribution of Large Pig for Renal Ischemia-Reperfusion and Transplantation Studies: The Preclinical Model

Animal experimentation is necessary to characterize human diseases and design adequate therapeutic interventions. In renal transplantation research, the limited number of in vitro models involves a crucial role for in vivo models and particularly for the porcine model. Pig and human kidneys are anatomically similar (characterized by multilobular structure in contrast to rodent and dog kidneys unilobular). The human proximity of porcine physiology and immune systems provides a basic knowledge of graft recovery and inflammatory physiopathology through in vivo studies. In addition, pig large body size allows surgical procedures similar to humans, repeated collections of peripheral blood or renal biopsies making pigs ideal for medical training and for the assessment of preclinical technologies. However, its size is also its main drawback implying expensive housing. Nevertheless, pig models are relevant alternatives to primate models, offering promising perspectives with developments of transgenic modulation and marginal donor models facilitating data extrapolation to human conditions

Best-bet integrated strategies for containing drug-resistant trypanosomes in cattle

Background African animal trypanosomosis is a major constraint to the rearing of productive livestock in the sub-humid Sudan-Sahel zone of West Africa where cotton is grown. Trypanosomosis is mainly controlled using trypanocidal drugs, but the effective use of drugs is threatened by the development of widespread resistance. This study tested integrated best-bet strategies for containment and/ or reversal of trypanocide resistance in villages in south-east Mali where resistance has been reported. Methods Four sentinel villages each from an intervention area (along the road from Mali to Burkina Faso) and a control area (along the road from Mali to Côte d’Ivoire) were selected for the study. Tsetse control was based on deltamethrin-treated stationary attractive devices and targeted cattle spraying between March 2008 and November 2009. Trypanosome-positive cattle were selectively treated with 3.5 mg/kg diminazene aceturate. Strategic helminth control using 10 mg/kg albendazole was also undertaken. During the intervention, tsetse densities along drainage lines, trypanosome infections and faecal egg counts in risk cattle (3 to 12 months of age) were monitored. Results Catch reductions of 66.5 % in Glossina palpalis gambiensis and 90 % in G. tachinoides were observed in the intervention area. Trypanosome prevalence was significantly (p < 0.05) lower in the intervention area (2.3 %; 1.3-3.6 %) compared to the control area (17.3 %; 14.8-20.1 %). Albendazole treatment resulted in a faecal egg count reduction of 55.6 % and reduced trypanosome infection risk (2.9 times lower than in the placebo group) although not significantly (p > 0.05). Further studies are required before confirming the existence of albendazole resistant strongyles in the study area. Conclusion Integration of best-bet strategies in areas of multiple drug- resistance is expected to reduce trypanosome infection risk thus contributing to containment of trypanocidal drug resistance. Integrated best-bet strategies could therefore be considered a viable trypanosomosis control option especially in areas where multiple drug-resistance has been reported