454 research outputs found

    Urbanisation et nouveaux modes de transport urbain en Afrique de l’Ouest : cas de la ville de Bamako (Mali)

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    Le transport collectif urbain de Bamako constitue de nos jours un problĂšme de mobilitĂ© qu’il est important de mieux comprendre en vue de mener des actions collectives. L’urbanisation et la croissance dĂ©mographique accentuent la demande de mobilitĂ©. Cet article se propose d’analyser la place qu’occupe les motos taxis dans le de transport dans la ville de Bamako. Les entretiens individuels ont Ă©tĂ© menĂ©s auprĂšs des Les acteurs en charge de l’organisation du transport, les usagers, les syndicats et les conducteurs des motos taxis. Aussi, ces acteurs ont Ă©tĂ© observĂ©s sur le terrain. L’analyse a mis en exergue l’intĂ©gration des motos taxis dans le transport urbain de la ville de Bamako. Il rĂ©sulte de l’enquĂȘte que l’évolution de ces modes de transport rĂ©pond Ă  la demande de dĂ©placements quotidiens entre les diffĂ©rents secteurs de la ville. La croissance urbaine de Bamako suscite une forte demande en termes de mobilitĂ©. Cependant, le secteur de transport des motos taxis nĂ©cessite une meilleure organisation pour pouvoir rĂ©pondre de façon durable Ă  la demande de la population. Les autoritĂ©s municipales se plaignent de l’inadaptation des infrastructures routiĂšres pour ces motostaxis. Les accidents provoquĂ©s par les conducteurs de moto taxi et la mĂ©connaissance du code de la route le problĂšme majeur de ce secteur de transport. L’augmentation du nombre de motos taxis aiguise la rivalitĂ© sur certaines lignes entre les conducteurs des motos taxis et de SOTRAMA. Cette rivalitĂ© serait mal gĂ©rĂ©e par les autoritĂ©s locales selon les conducteurs de moto taxi. En rĂ©pondant Ă  cette demande, de nombreuses questions sont soulevĂ©es comme l’étalement urbain l’organisation du transport urbain. Urban public transport in Bamako is nowadays a mobility problem that is important to understand better in order to take collective actions. Urbanization and population growth in the city are accentuating the high demand for mobility. This article analyses the place of motorcycle taxis in the transport system in the city of Bamako. Individual interviews were conducted with the actors in charge of transport organization, users, trade unions and motorcycle taxi drivers. In addition, these actors have been observed in the field. The analysis highlighted the integration of motorcycle taxis in urban transport of Bamako. It results from the investigation that the evolution of these modes of transport responds to the demands of daily travel between different areas of the city. Bamako's urban growth is creating a strong demand for mobility. However, the motorcycle taxis transport sector requires better organization to be able to meet the population's demand in a sustainable way. The municipal authorities complain about the inadequacy of the road infrastructure for the circulation of these motorcycle taxis. Accidents caused by motorcycle taxi drivers and lack of knowledge of the traffic regulations are the major problem in this transport sector. The increase in the number of motorcycle taxis is sharpening the rivalry on certain routes between motorcycle taxi drivers and SOTRAMA drivers. This rivalry is said to be poorly managed by the local authorities according to the motorcycle-taxi drivers. In responding to this demand, many questions are raised such as urban sprawl, the organization of urban transport

    Environmental forensics in groundwater coupling passive sampling and high resolution mass spectrometry for screening

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    International audienceOne of the difficulties encountered when monitoring groundwater quality is low and fluctuating concentration levels and complex mixtures of micropollutants, including emerging substances or transformation products. Combining passive sampling techniques with analysis by high resolution mass spectrometry (HRMS) should improve environmental metrology. Passive samplers accumulate compounds during exposure, which improves the detection of organic compounds and integrates pollution fluctuations. The Polar Organic Chemical Integrative Sampler (POCIS) were used in this study to sequester polar to semi-polar compounds. The methodology described here improves our knowledge of environmental pollution by highlighting and identifying pertinent compounds to be monitored in groundwater.The advantage of combining these two approaches is demonstrated on two different sites impacted by agricultural and/or urban pollution sources where groundwater was sampled for several months. Grab and passive sampling were done and analyzed by liquid chromatography coupled to a hybrid quadrupole time-of-flight mass spectrometer (LC-QTOF). Various data processing approaches were used (target, suspect and non-target screening). Target screening was based on research from compounds listed in a homemade database and suspect screening used a database compiled using literature data. The non-target screening was done using statistical tools such as principal components analysis (PCA) with direct connections between original chromatograms and ion intensity. Trend plots were used to highlight relevant compounds for their identification. The advantage of using POCIS to improve screening of polar organic compounds was demonstrated. Compounds undetected in water samples were detected with these tools. The subsequent data processing identified sentinel molecules, molecular clusters as compounds never revealed in these sampling sites, and molecular fingerprints. Samples were compared and multidimensional visualization of chemical patterns such as molecular fingerprints and recurrent or specific markers of each site were given

    Barriers of Knowledge Transfer between Globally Distributed Teams in ICT Product Development

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    Increased globalization has generated a growth of globally distributed teams, which are characterized by geographical distance and used by organizations to increase innovation. However, to be able to collaborate effectively, teams are obligated to continuously conduct knowledge transfer (KT) between different geographical locations. Thus, this paper focused on identifying the main barriers that globally distributed teams face in conducting KT and how these barriers are unraveled. Based on an interpretative case study of a product development unit (PDU) in research and development (R&D) department of a telecom company, we identified eight main barriers that hinder the KT between globally distributed teams. These barriers are; knowledge embeddedness, knowledge accessibility and documentation gaps, knowledge complexity, knowledge problematic articulability, ICT tools reliance vs. face to face, inefficient ICT tools utilization, inefficient IT support, and lack of formal processes and guidelines

    DĂ©veloppement de nouveaux programmes de protection en Afrique de l'Ouest

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    Des ravageurs des cultures plus virulents ou résistants aux pesticides apparaissent. Le cotonnier n'est pas épargné. Les chercheurs analysent les facteurs de régulation de ces populations puis expérimentent des solutions avec les agriculteurs. Le Cirad, en complément d'une protection chimique raisonnée, propose des pratiques culturales et des variétés ayant un certain degré de résistance à un ravageur considéré. Différentes méthodologies pour la caractérisation de biotypes et la transformation génétique du cotonnier sont décrites. Des programmes de protection sont développés en Afrique de l'Ouest, comme la lutte étagée ciblée : le calcul d'un seuil économique permet d'ajuster les produits et leurs doses en fonction des résultats d'observations de terrain. Les agriculteurs économisent ainsi 40 à 50 % des quantités de produits. Les observations constituent le principal facteur limitant : une formation soutenue et des adaptations locales sont nécessaires. Les expériences acquises permettent d'envisager une simplification de ces observations. La prévention et la gestion de la résistance des insectes aux pesticides est un sujet de préoccupation majeure de la recherche : la résistance aux pyréthrinoïdes d'Helicoverpa armigera sur cotonnier en est une illustration. Il est primordial d'assurer un suivi en laboratoire et sur le terrain grùce à un réseau international : c'est le cas en Afrique de l'Ouest et du Centre. Les mécanismes mis en cause sont à l'étude. La collaboration entre plusieurs pays et plusieurs filiÚres (par exemple coton et maraßchage), ainsi que le concours de différents services nationaux sont indispensables à la mise en place d'une protection intégrée des cultures
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