130 research outputs found

    Impact of indigenous storage systems and insect infestation on the contamination of maize with fumonisins

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    Four storage systems of maize commonly used by farmers in Benin, West Africa, were tested to determine their impact on infection of maize by Fusarium and subsequent contamination with fumonisins. The study showed that Fusarium incidence was significantly higher when maize was stored on a cemented floor in a house, a non ventilated facility (40.3 ± 17.4%), than in the other tested systems (p < 0.05). The lowest Fusarium incidence was recorded when maize was stored in a bamboo granary that is a ventilated facility (25.5 ± 13.5%) (p < 0.05). All maize samples from the tested storage systems were found to be fumonisin positive, with levels ranging from 0.6 to 2.4 mg/kg. Fumonisin level, overall, was found to decrease over the storage period, but not significantly in all the tested storage systems. Damage by lepidopterous pests was significantly and positively correlated with both infection of maize with Fusarium and contamination by fumonisin. In contrary, damage by coleopterous insects was significantly and negatively correlated with infection of maize with Fusarium and contamination by fumonisin. Avoiding the use of non-ventilated systems to store maize and reducing insect infestation in field and during storage are very important recommendations for farmers.Keywords: Maize, storage systems, Fusarium, fumonisins, insect infestatio

    Sexuality issue in the school environment in a capital city of a West African country

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    Background: Precociousness and abuse of unprotected sexual intercourses among teenagers promote sexually transmitted infections and unwanted pregnancies that often result in illegal induced abortions. The goal of this work is to study the knowledge, attitude and practice of students about sexuality.Methods: This is a cross-sectional and analytical study that took place from 1st March to 30th May 2015. All registered secondary students in both secondary schools Behanzin and Toffa 1er from Porto-Novo city are included. We used a multiple choice and open questions.Results: The survey concerns 1304 students. Among them, 57% are female and 43% are male. The students’ average age is 18.71±2.31years with extremes of 13 and 25 years. The majority of students in our sample (66.9%), the ideal age for first sexual intercourse is between 15 and 19 years with 60.4% for boys and 65.0% for girls. In our sample, 6 to 7 students out of 10 have at least one sexual intercourse. Among boys, we estimated 7 to 8 cases out of 10 and among girls 5 to 6 out of 10 cases. On the whole, 44.9% of students agreed to have sexual intercourse before marriage. Out of 1304 students, 50.0% have their first sexual intercourse between 15 and 19 years old and 47.2% of these sexual intercourses were unprotected. Having many sexual partners is more observed among boys. Sexually transmitted diseases are known by students of our sample in the following proportions: HIV/AIDS (93.2%), Gonorrhoea (44.2%), Syphilis (21.2%), Chancroid (6.2%), Genital trichomoniasis (5.4%). Out of 433 sexually active girls who were involved in the present study, 165 (38.1%) had at least one unwished pregnancy and 144 which is 87.3% resulted in induced abortions.Conclusions: Present study showed that the majority of students are sexually active and most of sexual intercourses are unprotected despite the knowledge about sexually transmitted diseases. This attitude is revealed in a certain rate of unwished pregnancies resulting in a significant proportion of induced abortions

    Evaluation des Coupes-Rases Par la TĂ©lĂ©dĂ©tection et Les SystĂšmes d’Information GĂ©ographique dans la ForĂȘt ClassĂ©e de DjigbĂ© (BĂ©nin)

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    Le paysage des forĂȘts classĂ©es Ă©tant de plus en plus anthropisĂ© Ă  cause de la pression dĂ©mographique, optimiser le suivi du prĂ©lĂšvement du bois serait un dĂ©fi pour la gestion rationnelle des forĂȘts au sud BĂ©nin. A cet effet, cette Ă©tude a pour objectif d’évaluer l’exploitation forestiĂšre faite par coupes-rases. Ce qui implique une estimation de l’évolution du massif forestier et donc de la disponibilitĂ© en bois pour une gestion planifiĂ©e et durable de la forĂȘt classĂ©e de DjigbĂ© (commune de ZĂš). La mĂ©thode utilisĂ©e relĂšve de la tĂ©lĂ©dĂ©tection et les SystĂšmes d’Information GĂ©ographique (SIG). Elle inclue la photo – interprĂ©tation par classification supervisĂ©e, le calcul de l’indice normalisĂ©e de vĂ©gĂ©tation (NDVI) aboutissant Ă  la restitution cartographique des coupesrases. Ainsi, la dĂ©tection des coupes-rases a Ă©tĂ© suivie Ă  partir des images satellitaires de type Landsat 8 des annĂ©es 2014 Ă  2017. La dĂ©tection automatisĂ©e des changements d’un Ă©tat vĂ©gĂ©tatif Ă  un Ă©tat non vĂ©gĂ©tatif basĂ©e sur l’analyse de l’indice normalisĂ© de la vĂ©gĂ©tation (NDVI) entre deux dates a Ă©tĂ© utilisĂ©e. Des missions de gĂ©orĂ©fĂ©rencement des zones de coupes-rases dans la forĂȘt classĂ©e de DjigbĂ© ont aidĂ© aux traitements des images Ă  partir du logiciel ENVI 4.7. Les coupes-rases dĂ©tectĂ©es ont par la suite Ă©tĂ© restituĂ©es par cartographie. Les rĂ©sultats de dĂ©tection des coupes-rases ont Ă©tĂ© statistiquement vĂ©rifiĂ©s par des matrices de confusion. Les emplacements de coupes-rases dĂ©tectĂ©es pendant la pĂ©riode DĂ©cembre 2014-dĂ©cembre 2015 diffĂšrent de celle de dĂ©cembre 2015-janvier 2017. Chaque classe de coupe regroupĂ©e suivant un degrĂ© de certitude, respectant donc un cloisonnement donnĂ©. Ce qui renseigne sur la prĂ©cision de la mĂ©thode automatisĂ©e de dĂ©tection. La dĂ©tection des coupes a Ă©tĂ© rĂ©alisĂ©e suivant trois valeurs de probabilitĂ© de prĂ©sence de coupes-rases. Ces valeurs de probabilitĂ© sont : faible (1σ), moyenne (2σ) et forte (3σ) dĂ©signĂ©es par l’expression « degrĂ© de certitude ». Quelle que soit la classe et la pĂ©riode, le nombre de coupe est plus important chronologiquement pour le degrĂ© de certitude faible (1σ), moyenne (2σ) et forte (3σ). Les coupes-rases de dĂ©tection supĂ©rieure ou Ă©gale Ă  1ha dans la plantation domaniale de DjigbĂ© couvrent 234,63 ha. Ce qui induit une estimation de la disponibilitĂ© en bois qui est diminuĂ©e de cette mĂȘme superficie dĂ©tectĂ©e durant la pĂ©riode prise en compte par l’étude. ConsidĂ©rant le classement des coupes-rases suivant les degrĂ©s de certitude « moyenne » et « forte », sur l’ensemble des 234,63 ha, les proportions dĂ©tectĂ©es ont Ă©tĂ© respectivement de 76 et de 24 %. La dĂ©tection par images satellitaires et la cartographie est un outil de suivi et d’évaluation pertinent. Cet outil contribue Ă  l’analyse pĂ©riodique d’images satellitaires et la simulation de l’évolution de la ressource bois en plantation. Les rĂ©sultats de cette Ă©tude permettent ainsi d’apprĂ©cier avec impartialitĂ© l’évolution du prĂ©lĂšvement et le suivi Ă  distance de l’exploitation du bois. L’appropriation de l’utilisation de cet outil par les acteurs forestiers pour l’estimation de la ressource bois disponible, contribuerait Ă  une meilleure gestion des forĂȘts. The landscape of classified forests us being more and more anthropized because of demographic pressure. As a result, optimizing the monitoring of wood removal would be a challenge for the rational management of forests in southern Benin. This paper focuses on assessing logging done by clear-cutting. This implies an estimate of the evolution of the forest massif and therefore of the availability of wood for a planned and sustainable management of the classified forest of DjigbĂ© (commune of ZĂš). The method used is based on remote sensing and Geographic Information Systems (GIS). It includes photo interpretation by supervised classification and the calculation of the standardized vegetation index (NDVI) leading to the cartographic restitution of the clear-cuts. Thus, the clearing detection was followed from Landsat 8 type satellite images from2014 to 2017. Automated detection of changes from a vegetative to a non-vegetative state based on the analysis of the index normalized vegetation (NDVI) between two dates was used. Georeferencing missions of clearcut areas in the classified forest of DjigbĂ© helped image processing using the ENVI 4.7 software. The level cuts detected were subsequently restored by mapping. The shaving cutter detection results were statistically verified by confusion matrices. The clearing locations detected during the period December 2014 to December 2015 differ from that of December 2015 to January 2017. Each cutting class was grouped according to a degree of certainty, thus respecting a given partitioning. This provides information on the accuracy of the automated detection method. The detection of the cuts was carried out according to three values of probability of the presence of clear-cuts. These probability values are: low (1σ), medium (2σ), and high (3σ) designated by the expression "degree of certainty". Whatever the class and the period, the number of cuts is more important chronologically for the degree of certainty low (1σ), medium (2σ), and strong (3σ). The leveling shafts of detection greater than or equal to 1 ha in the national plantation of DjigbĂ© cover 234.63 ha. This leads to an estimate of the availability of wood, which is reduced by the same area detected during the period taken into account by the study. Considering the classification of clearcuts according to the degrees of certainty "medium" and "strong", on the whole of the 234.63 ha, the proportions detected were respectively 76 and 24%. Detection by satellite images and mapping is a relevant monitoring and evaluation tool. This tool contributes to the periodic analysis of satellite images and the simulation of the evolution of the wood resource in plantation. The results of this study thus allow an impartial assessment of the evolution of the harvest and remote monitoring of logging. The appropriation of the use of this tool by forest stakeholders, for the estimation of the available wood resource, would contribute to better forest management

    Capacity building under the aflatoxin and nutrition platform 2012-2013

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    Environmentalism in the EU-28 context: the impact of governance quality on environmental energy efficiency

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    Environmental policies are a significant cornerstone of a developed economy, but the question that arises is whether such policies lead to a sustainable growth path. It is clear that the energy sector plays a pivotal role in environmental policies, and although the current literature has focused on examining the link between energy consumption and economic growth through an abundance of studies, it does not explicitly consider the role of institutional or governance quality variables in the process. Both globalization and democracy are important drivers of sustainability, while environmentalism is essential for the objective of gaining a “better world.” Governance quality is expected to be the key, not only for economic purposes but also for the efficiency of environmental policies. To that end, the analysis in this paper explores the link between governance quality and energy efficiency for the EU-28 countries, spanning the period 1995 to 2014. The findings document that there is a nexus between energy efficiency and income they move together: the most efficient countries are in the group with higher GDP per capita. Furthermore, the results show that governance quality is an important driver of energy efficiency and, hence, of environmental policies.University of Granad

    Preservation of cassava (Manihot esculenta Crantz): A major crop to nourish people worldwide

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    This chapter considers the increase in cassava production and processing into a wide range of traditional and improved cassava-based products worldwide. Toxic cyanogenic glycosides are removed from high cyanogenic cassava cultivars by known techniques prior to further processing. Therefore we also discuss the overall detoxification processes and steps as well as the shelf life and end-use of different cassava-based products

    Municipal Solid Waste in Mediterranean countries : Three contributions for a sustainable management

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    Au cours de ces derniĂšres annĂ©es, les DĂ©chets Solides Municipaux (DSM) se sont rĂ©vĂ©lĂ©s comme une problĂ©matique environnementale et Ă©conomique majeure dans tous les pays. Les quantitĂ©s collectĂ©es et les dĂ©penses publiques nĂ©cessaires Ă  leurs gestions croissent de façon insoutenable et ce, particuliĂšrement dans les pays en dĂ©veloppement (y compris ceux en transition). Face Ă  ce constat, notre thĂšse a pour objectif de proposer des Ă©lĂ©ments de comprĂ©hension ainsi que des recommandations pour les politiques publiques. Pour cela, nous avons combinĂ© une approche macroĂ©conomique, pour Ă©tudier les liens entre la quantitĂ© de DSM et la croissance Ă©conomique, Ă  une approche microĂ©conomique centrĂ©e sur la question du financement par une taxe incitative. Les contributions de cette thĂšse sont de trois ordres et ont pour rĂ©fĂ©rence les pays mĂ©diterranĂ©ens. La premiĂšre contribution a consistĂ© Ă  tester la viabilitĂ© de l’hypothĂšse de la Courbe Environnementale de Kuznets (CEK) dans un contexte d’ouverture au commerce international. Cette premiĂšre approche a permis de dĂ©celer une relation monotone croissante entre l’intensitĂ© de la production des DSM et la croissance Ă©conomique sur la pĂ©riode 1990-2010 et ce, quel que soit le niveau de revenu des pays. Ce qui nous conduit Ă  la conclusion d’une incompatibilitĂ© entre les objectifs de croissance et de prĂ©vention de la production des DSM. La deuxiĂšme contribution a Ă©tĂ© l’occasion de considĂ©rer, dans un modĂšle thĂ©orique, le recyclage informel qui est une caractĂ©ristique commune au pays en dĂ©veloppement. L’objectif de cette contribution a Ă©tĂ© d’une part d’analyser l’impact du recyclage informel sur l’efficacitĂ© d’une politique de taxation incitative et d’autre part, de dĂ©terminer les conditions optimales d’une telle politique en prĂ©sence du recyclage informel. En Ă©tudiant l’efficacitĂ© d’une politique de taxation directe de type tarification Ă  l’acte et d’une politique de taxation indirecte de type Deposit and Refund System (DRS), nous montrons que la prĂ©sence du recyclage informel ne permet pas de faire coĂŻncider optimum social et Ă©quilibre du marchĂ©. Cependant, la politique DRS peut ĂȘtre optimale, Ă  condition de subventionner Ă  la fois le recyclage formel et informel. Enfin, la troisiĂšme contribution est une Ă©tude Ă©conomĂ©trique des impacts du systĂšme de taxation incitative d’un pays riche mĂ©diterranĂ©en. Cette Ă©tude vient du constat selon lequel les pays riches, contrairement aux pays en dĂ©veloppement, mettent en Ɠuvre plusieurs taxes incitatives de façon concomitante. Nous Ă©valuons l’efficacitĂ© du systĂšme de taxation de la France, qui avec ses trois taxes incitatives est un cas d’école en la matiĂšre. Nous proposons dans cette contribution, Ă  l’aide de tests Ă©conomĂ©triques sur donnĂ©es dĂ©partementales, une mesure de l’élasticitĂ© de la quantitĂ© de DSM collectĂ©s, valorisĂ©s et Ă©liminĂ©s par rapport Ă  la Redevance sur l’EnlĂšvement des Ordures MĂ©nagĂšres (REOM), la ResponsabilitĂ© Élargie du Producteur (REP) et la Taxe GĂ©nĂ©rales sur les ActivitĂ©s Polluantes (TGAP). Les rĂ©sultats montrent une complĂ©mentaritĂ© des trois taxes avec une supĂ©rioritĂ© de la REOM pour inciter les mĂ©nages Ă  la prĂ©vention et Ă  la valorisation, et une supĂ©rioritĂ© de la REP pour inciter les collectivitĂ©s locales Ă  la substitution des technologies d’élimination Ă  celles de valorisationIn last decades, Municipal Solid Waste (MSW) has become a major environmental and economic problem in many countries. The quantity of MSW collected and the expenditures necessary for its management have rapidly increased, particularly in developing countries (including those in transition). Our thesis aims to shed light on the relationship between MSW collection and economic growth and to propose how public policy can sustainably manage this pollution. To attempt our objective, we combined a macro and micro economic approaches in theoretical and empirical studies. The contributions of this thesis are threefold and have the scope of Mediterranean countries. First, we complete the empirical literature on the validation of the Environmental Kuznets Curve hypothesis (EKC) by studying the relationship between MSW collected and the economic growth over the period 1990-2010. The main added value of this study is the use of multiple imputations methodology to control for the sample bias due to missing values. We find out that MSW collected monotonically increase with income whatever countries’ income level. This leads us to conclude that the economic growth and MSW prevention are not compatible. So in a second contribution, we investigate, in a theoretical model, the efficiency of using market-based incentives to reach to objective of waste prevention and diversion from disposal in developing countries. We consider the common phenomenon of waste picking in these countries and we analyze the conditions in which a policy of Deposit and Refund System (DRS) can help to achieve the first best optimum. We first analyze the impact of waste picking on the effectiveness of the user fee and the DRS, then we show that social optimum and market equilibrium can be hold by taxing consumer goods and by subsidizing both formal recycling and waste picking. Our third contribution in this thesis is an econometric evaluation of French MSW taxing system in order to test the hypothesis of the complementarity of direct and indirect MSW incentive taxes in developed countries, which implement simultaneously several incentives taxes. Using data aggregate at French administrative departments level, we assess the prevention and substitution effects of the three incentive taxes namely the French user fee (La Redevance d’EnlĂšvement des Ordures MĂ©nagĂšres), the Extended Producer responsibility and disposal tax levied at landfill and incineration (la Taxe GĂ©nĂ©rale sur les ActivitĂ©s Polluantes). We confirm the complementarity hypothesis of these taxes
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