In boreal summer, satellite measurements show that the central Sahara is the dustiest region of the planet. However, ground-based observations of the central Sahara have been limited to its outer edges, leaving a void in observations approximately 1 million km² in area. The Fennec Project has been the first campaign to instrument this remote but climatologically important region. This thesis uses these new observations to detect and explain the atmospheric mechanisms that make the central Sahara the summer global dust maximum. Four atmospheric mechanisms are found to cause dust storms in the central Sahara in June 2011 and June 2012. These are cold pool outflows, low-level jets (LLJs), monsoon surges and dry convective plumes. Dust may be emitted locally by these phenomena, or be advected, principally by cold pools. In both field seasons, dust emission by cold pool outflows is the most important dust mechanism, causing roughly half of the total dust loadings at the Fennec supersite of Bordj-Badji Mokhtar (BBM), the closest station to the dust maximum. The second most important mechanism is dust advection by cold pools (roughly 30% dust at BBM), followed by dust emission by monsoon surges, LLJs and finally dry convective plumes (only 2% dust at BBM). Although June 2012 was significantly more dusty than June 2011, the relative importance of the different atmospheric dust mechanisms at BBM did not change. At the automatic weather stations (AWSs) across the remote desert, cold pools and LLJs are by far the most frequently detected atmospheric dust mechanisms. LLJs are particularly common in the Atlantic Inflow in western Mauritania and in the north-easterly Harmattan in western Algeria. Cold pools are much more frequent at BBM, the station under the greatest moist monsoon influence, than at the AWSs to the north. Detection of advected dust is a particular difficulty without dedicated dust-detection instrumentation or human observers (e.g. at the AWSs). Detection of dust emission mechanisms can be very successful with only routine ground observations and satellite measurements, but quantifying the associated dust burden without dedicated dust instruments is problematic. The choice of instrumentation for dust measurement is crucial. Because cold pool outflows - the most important dust mechanism - frequently occur at night or under cloud, sun photometers miss about half of cold pool dust. Lidars have the advantage of providing height resolved dust profiles, but they suffer from attenuation in thick dust. The nephelometer proved to be the most reliable dust instrument. Although LLJs occurred on 21/28 mornings at BBM in June 2011, only five of these jets led to dust emission. Calculations of momentum exchanges through the atmospheric column show that momentum mix-down from the jet core is the cause of dust emission on these occasions, but that the LLJ has to be particularly strong (≥ 16 m s^-1) to result in dust emission at the surface. Met Office Africa-LAM underestimates monsoon LLJ wind profiles and ERA-Interim reanalysis underestimates both monsoon and Harmattan LLJ wind profiles. At the surface, the Met Office Africa-LAM and GLOBAL models significantly underpredict the frequency of observed wind speeds &gt6 m s^-1. This will cause them to significantly underestimate dust emission, as emission is a threshold process proportional to the cube of wind speed. A particularly interesting implication of the research presented here is that the central Sahara is likely much more dusty than previously thought. This is because almost all of the techniques currently used to study dust in the region are systematically biased to result in underestimates of dust burden. Cold pools are the most important dust mechanism but, since they rarely occur during the daytime or in cloud-free conditions they are often missed by sun photometers. Many will be missed by satellites that cannot retrieve below cloud and satellites that pass over the Sahara in daylight hours (e.g. the A-train). A commonly-used satellite dust detection algorithm often misses dust under moist (i.e. cold pool) conditions. Cold pools cannot be simulated by models without explicit convection, which requires very high spatial resolution. Finally, the numerical models assessed here significantly underpredict the frequency of wind speeds over the dust emission threshold. The Sahara is probably much dustier than current estimates suggest.

"Mémoire présenté à la Faculté des études supérieures en vue de l'obtention du grade de maîtrise en droit des technologies de l'information" / L'accès au droit en Afrique de l'Ouest est difficile et restreint, et cela pour de nombreuses raisons. Parmi celles-ci peut être citée la faible diffusion papier des ressources juridiques nationales, qui est en partie due au manque de moyens matériels et financiers. Or, depuis une dizaine d'années, des projets de diffusion des ressources juridiques via Internet se développent, donnant ainsi un accès libre aux informations juridiques publiques. Ce mode de diffusion du droit représente une alternative pour les États africains, leur permettant de bâtir de nouvelles stratégies favorisant l'accès au droit. Néanmoins, ce nouveau mode de diffusion du droit fait ressurgir une réflexion relative à la nature plurale des droits ouest africains et de la place des droits originellement africains dans ces nouvelles stratégies. La présente analyse montre que l'utilisation des nouvelles technologies, telles qu'Internet, dans des stratégies de diffusion du droit est pertinente, à la condition que les États africains redéfinissent leur culture juridique, en prenant en considération les sources originellement africaines afin qu'elles prennent place dans la diffusion du droit via Internet. / Access to legal information in West Africa is difficult and restricted because of a weak dissemination network. The insufficient publication and distribution of national legal resources can partly be attributed to a lack of financial and material resources. Over the past ten years, legal resource publication projects on the Web have been developed to offer free access to public legal information. This type of document dissemination model represents an alternative solution for African States by allowing them to elaborate new strategies to increase legal information dissemination. This new law publishing model, however, has brought about the need to reconsider the pluralistic nature of West African laws and the place these originally African laws occupy within the new strategies being put forth. The following analysis demonstrates how the use of new technologies such as the Internet has proven to be relevant for legal resource publication and distribution insofar as African states always take into consideration originally African sources when redefining their legal cultures through the dissemination of their laws via the Internet.

Différentes réalités et contextes actuels mondiaux font en sorte que de plus en plus de gens envisagent la migration comme projet de vie. La présente recherche s’intéresse à l’imaginaire migratoire comme facteur de mobilité, mais également comme facteur de modulation des réactions et du regard qu’entretiendra le migrant en rapport avec son vécu migratoire. Ainsi, la réflexion s’amorce en Afrique de l’Ouest, tandis que de jeunes Africains instruits et qualifiés élaborent un projet de migration volontaire vers le Canada, plus précisément dans la région du Québec. C’est investi de leur désir de l’Ailleurs, des représentations de l’Occident, de leur besoin de se réaliser et de l’impossibilité qu’ils rencontrent à accéder à la vie professionnelle souhaitée en Afrique qu’ils migrent vers le Canada. Quoiqu’ils soient dotés d’une détermination et d’un optimisme considérable, la rencontre entre l’imaginé et le quotidien de la vie au Québec comme immigrant et comme émigrant n’est pas toujours facile. Elle viendra révéler la profondeur du rêve, des mythes et des ambitions; les failles intérieures individuelles, les valeurs et les ambivalences de chacun, mais surtout la capacité qu’aura l’individu à revoir son imaginaire, à effectuer la réappropriation de son expérience migratoire et à élaborer de nouveaux projets. L’écart vécu par le sujet entre l’imaginé et le rencontré nous questionnera sur ce que véhiculent les messages et les images en circulation sur le Canada et l’Occident. Aussi, il témoignera de la prédominance de la préparation factuelle et psychologique de l’individu pour anticiper et mieux accueillir les réalités du parcours migratoire. / Different realities and contexts in today’s world are causing more and more people to consider migration as a life plan. This study is interested in their imagined migration as a mobility factor, but also as a modulation factor in the reactions and views of migrants in relation to their migration experience. Thus, this study begins in West Africa, where young educated and qualified Africans eagerly plan their migration to Canada, and Quebec in particular. Their migration to Canada is fuelled by a longing to go abroad, representations of the West, their quest for self-fulfillment and the impossibility of achieving their desired career plans in Africa. Although they are filled with a great deal of determination and optimism, the clash between what they imagined and the reality of daily life in Quebec as immigrants and emigrants is not always easy. This study will not only reveal the depth of their dreams, myths and ambitions, but their individual flaws, values and uncertainties, and above all, their ability to re-examine their imagined migration, reclaim the migration experience and make new plans. The difference between the imagined experience and the actual experience will lead us to question what conveys the messages and images that circulate about Canada and the West. Moreover, it will demonstrate the predominance of the factual and psychological preparation undertaken by individuals to anticipate and more readily accept the realities of the migration experience.

L’objectif du travail est la mise en place d’un pôle intégré d’excellence pour l’énergie solaire en Afrique de l’Ouest. Trois pays y ont été identifiés comme territoires d’expérimentation (Burkina Faso ; Côte d’Ivoire ; Sénégal). Les enquêtes de terrain dans ces territoires suivies d’une analyse de filière a permis de mettre en évidence les interactions entre les acteurs de la filière solaire dans les trois pays (pouvoirs publics ; recherche et formation ; entreprises ; société civile ; utilisateurs). La réalisation de matrices d’influences directes à partir des résultats de l’analyse de la filière solaire dans les pays a permis de comprendre le faible niveau de relations entre les acteurs interdépendants. Les résultats révèlent que les pouvoirs publics demeurent les acteurs dominants de la filière solaire dans les trois pays, malgré la faiblesse de leur volonté. Les entreprises privées et les organisations non gouvernementales sont des acteurs relais (entre les pouvoirs politiques et les utilisateurs) qui jouent un rôle d’installation d’équipements solaires et de développement de projets surtout en milieux ruraux. Les utilisateurs (consommateurs) de la filière solaire sont des acteurs « dominés » qui n’ont pas d’influence sur les autres acteurs notamment les pouvoirs politiques. La recherche et la formation dont les résultats se limitent à des formations théoriques ou des expérimentations non diffusées restent des acteurs isolés. Le pôle intégré construit permet de stabiliser, régulariser et faire circuler entre eux les connaissances produites et les capacités développées par les acteurs en interactions au sein d’un écosystème / The purpose of this thesis is the building an integrated excellence pole for solar energy in West Africa. Three countries have been identified as areas for experimentation (Burkina Faso; Cote d’Ivoire; Senegal). Field surveys in these territories and sector analysis allow highlighting the interactions among the solar sector actors in the three countries (political field, research and training, business, civil society, users). The realization of direct influence matrices from the results of solar energy sector analysis in the countries helped us to understand the low level of relationship among interdependent stakeholders.The results show that the public authorities are still the dominant players, despite the weakness of their willingness. Private companies and non-governmental organizations have a liaison role playing an essential task of solar equipment installation and projects development especially in rural areas. The users of the solar sector are dominated players without influence on the other players especially the public authorities. The research actors clearly appear as isolated: Their results are generally limited to theoretical courses, the conduct of experiments and prototypes that rarely reach public release phase. The constructed pole allows to stabilize, to settle and to make the produced knowledge circulate and the capacities developed by the actors in interaction within an ecosystem.

L’accès aux interventions de la prévention de la transmission mère-enfant (PTME) est limité en Afrique de l’Ouest et les mères infectées continuent de transmettre le virus à leurs enfants. D’importantes questions sur le diagnostic et traitement antirétroviral (TAR) précoce pour les enfants dans les pays à ressources-limitées restent sans réponses. La simulation est un outil utile qui permet d’intégrer toutes les données disponibles et de projeter à long terme les retombées cliniques et économiques de l’infection à VIH pédiatrique et informer les politiques de santé. Bien que les modèles de simulation soient mathématiquement sophistiqués, l’utilité des études basées sur la simulation dépend de la qualité des données de départ. L’objectif principal de ce travail était de fournir des données originales et récentes sur la mortalité, morbidité sévère et recours aux soins chez les enfants infectés par le VIH suivis dans des programmes de soins, avant et après initiation du TAR, dans le contexte du passage à l’échelle du TAR depuis 2004 en Afrique de l’Ouest. Nos résultats font ressortir un taux de mortalité comparable à d’autres études, atteignant 5.5% après 18 mois de suivi dans une cohorte d’enfants non traités par TAR, inclus à un âge médian de 5 ans. Les taux de morbidité sévère étaient élevés chez les enfants non traités mais aussi traités. Nous avons rapportés qu’une hospitalisation sur trois était provoquée par une morbidité infectieuse, évitable par une prophylaxie par cotrimoxazole, une intervention simple et efficace qui n’est toujours pas accessible à tous en Afrique de l’Ouest. Nous avons également observé un recours aux soins importants associé à la morbidité sévère. Cependant, parmi les enfants non traités, comme les traités, le recours aux soins était plus faible parmi les enfants les plus immunodéprimés. Le principal obstacle aux recours aux soins était le coût associé pour les familles. Enfin, les enfants qui initiaient un TAR l’initiaient trop tard, à un stade trop avancée de la maladie pour une restitution immunitaire pour âge ; la probabilité de rattraper une immunité normale était encore plus faible chez les enfants âgés > 5 ans comparé aux plus jeunes. Globalement, ce travail met en avant la nécessité de la mise en place de stratégies de diagnostic et traitement précoce. Optimiser le parcours de soins ainsi implique des interventions à de nombreux niveaux du système de soins et aucune approche unique ne pourra être efficace. De plus, les coûts liés à une prise en charge à vie devront être estimés dans un contexte où le VIH devient une maladie chronique engendrant un plus gros recours aux soins. Intégrer ces données dans un modèle de simulation permettra d’informer les politiques de santé et les soignants afin d’identifier les stratégies les plus efficaces et coût-efficaces pour le diagnostic, le traitement et le suivi à long terme de l’enfant infecté par le VIH dans les pays à ressources limitées. / Access to prevention of mother-to-child transmission (PMTCT) interventions is limited in West Africa and mothers continue to transmit HIV disease to their children. Important questions on early HIV diagnosis and early antiretroviral therapy (ART) for children in resource-limited settings remain unanswered. Computer simulation models can provide helpful information to project long-term patient outcomes and inform health policy. Although simulation models are computationally sophisticated, the usefulness of the results of modelling studies depends on the quality and accuracy of the data on which they are based. The main objective of the following work was to provide accurate and up-to-date data on mortality, severe morbidity and healthcare resource utilisation in HIV-infected children enrolled in care, before and after ART initiation in the context of the access to ART roll-out since 2004 in West Africa. Our findings suggest mortality rates comparable to those of other studies, reaching 5.5% by 18 months of follow-up in children enrolled in cohorts at a median age of 5 years who had not yet initiated ART. Severe morbidity rates were high, in both ART-treated and untreated children. We found that one hospitalisation in three was caused by an infectious disease, avoidable by cotrimoxazole prophylaxis, a simple and efficient intervention that is still not accessible to all in West Africa. We also reported substantial rates of healthcare resource utilisations associated with this severe morbidity. However, in both untreated and ART-treated children, healthcare resource utilisation was lower in the sickest, most immunodeficient children. Access to healthcare remains limited and one of the explanations we put forward are the costs borne by the families. Finally, children on ART remain initiated at a too late stage to be able to restore normal immunity for age; this is even less likely in those who initiated ART after 5 years compared to younger children. Overall, this work underlines the need for an effective early HIV diagnosis and treatment. Optimising this requires interventions at multiple levels of the healthcare system and no single approach is likely to be effective. Furthermore, lifetime treatment costs will need to be assessed as HIV becomes a chronic disease leading to greater healthcare resource utilisation. Integrating these data in computer simulation models will assist healthcare providers and policy-makers to identify the most effective and cost-effective strategies for diagnosis, treatment and monitoring of paediatric HIV in low income countries.

La coopération structurelle et opérationnelle de défense et de sécurité entre la France et les Etats francophones de la CEDEAO est caractérisée par des configurations différenciées observées d’un Etat à un autre et par la prévalence d’une interdépendance stratégique entre la France et ses partenaires. Depuis 2007, outre le renouvellement des accords instituant un partenariat de défense entre la France et certains de ces partenaires, cette coopération s’insère dans un contexte marqué par la régionalisation des enjeux et des solutions de sécurité ainsi que l’intérêt de nouveaux acteurs favorisant un afflux d’offres d’assistance et de coopération. On sort donc du « huis-clos » bilatéral des accords post-indépendances et des pratiques qui en ont résulté, pour analyser la relation Afrique-France à l’aune de plusieurs paramètres déterminés par ses évolutions récentes. Cette étude ambitionne dans une perspective postcolonialiste, de déconstruire les oppositions binaires et la généralisation en apportant des outils de mesure et de comparaison de la coopération, dans le temps et dans l’espace ; en mettant en exergue les nuances ; en proposant une typologie et surtout en relevant les bénéfices que procure la coopération à chaque catégorie d’acteur. A partir de la théorie du comportement coopératif de Robert Axelrod, notamment sa variante « donnant-donnant », il est démontré que la pérennisation de la coopération réside dans l’intérêt des parties à coopérer qui surpasse l’abstention. En raison de ce dépassement du « fait » et de « l’héritage colonial », le postcolonialisme pourrait alors représenter un modèle d’analyse des relations internationales contemporaines et la Francophonie, un espace empreint de « profondeur stratégique ». / Structural and operational defense and security cooperation between France and Francophone states of ECOWAS is characterized by different configurations depending on the perspectives of each stakeholder. They are also characterized by strategic interdependence between France and its partners. Since 2007, besides the renewal of agreements setting up a defence partnership between France and its partners, this cooperation is taking place in a context marked by the regionalization of stakes and security responses in the West African region and the increasing interest of non-traditional actors providing increasing flows of assistance and cooperation. These new parameters breaking the traditional behind “closed-doors” of bilateral post-independance agreements, practices and interpretations that were traditionally mobilized to analyse Africa-France relations. By using a postcolonial perspective, this study aims at deconstructing conventional binary oppositions and generalizations by bringing in new tools of comparison of cooperation, in time and space and by highlighting the nuances. It also aims at suggesting a typology of the benefits that different categories of actors gain from this cooperation. Building on Robert Axelrod’s theory of cooperative attitude, and its ”win-win” component, this study demonstrates that the lasting of cooperation resides in the interests each party finds in cooperating beyond abstaining. Due to this capacity to rise above the "fact" and "colonial legacy", the postcolonialism could then be a model of analysis of contemporary international relations and “Francophonie”, a space marked of "strategic depth".

Between 1916 and 1928 Dr Louis Fourie, Medical Officer for the Protectorate of South West Africa and amateur anthropologist, amassed a collection of some three and a half thousand artefacts, three hundred photographs and diverse documents originating from or concerned with numerous Khoisan groups living in the Protectorate. He gathered this material in the context of a complex process of colonisation of the area, in which he himself was an important player, both in his official capacity and in an unofficial role as anthropological adviser to the Administration. During this period South African legislation and administration continued the process of deprivation and dehumanisation of the Khoisan that had begun during the German occupation of the country. Simultaneously, anthropologists were constructing an identity for the Khoisan which foregrounded their primitiveness. The tensions engendered in those whose work involved a combination of civil service and anthropology were difficult to reconcile, leading to a form of melancholia. The thesis examines the ways in which Fourie’s collection was a response to, and a part of the consolidation of, these parallel paradigms. Fourie moved to King William’s Town in South Africa in 1930, taking the collection with him, removing the objects still further from their original habitats, and minimising the possibility that the archive would one day rest in an institution in the country of its origin. The different parts of the collection moved between the University of the Witwatersrand and a number of museums, at certain times becoming an academic teaching tool for social anthropology and at others being used to provide evidence for a popular view of the Khoisan as the last practitioners of a dying cultural pattern with direct links to the Stone Age. The collection, with its emphasis on artefacts made in the “traditional” way, formed a part of the archive upon which anthropologists and others drew to refine this version of Khoisan identity in subsequent years. At the same time the collection itself was reshaped and re-characterised to fit the dynamics of those archetypes and models. The dissertation establishes the recursive manner in which the collection and colonial constructs of Khoisan identity modified and informed each other as they changed shape and emphasis. It does this through an analysis of the shape and structure of the collection itself. In order to understand better the processes which underlay the making of the Fourie Collection there is a focus on the collector himself and an examination of the long tradition of collecting which legitimised and underpinned his avocation. Fourie used the opportunities offered by his position as Medical Officer and the many contacts he made in the process of his work to gather artefacts, photographs and information. The collection became a colonial artefact in itself. The thesis questions the role played by Fourie’s work in the production of knowledge concerning the Bushmen (as he termed this group). Concomitant with that it explores the recursive nature of the ways in which this collection formed a part of the evidentiary basis for Khoisan identities over a period of decades in the twentieth century as it, in turn, was shaped by prevailing understandings of those identities. A combination of methodologies is used to read the finer points of the processes of the production of knowledge. First the collection is historicised in the biographies of the collector himself and of the collection, following them through the twentieth century as they interact with the worlds of South West African administrative politics, anthropological developments in South Africa and Britain, and the Khoisan of the Protectorate. It then moves to do an ethnography of the collection by dividing it into three components. This allows the use of three different methodologies and bodies of literature that theorise documentary archives, photographs, and collections of objects. A classically ethnographic move is to examine the assemblage in its own terms, expressed in the methods of collecting and ordering the material, to see what it tells us about how Fourie and the subsequent curators of the collections perceived the Khoisan. In order to do so it is necessary to outline the history of the discourses of anthropologists in the first third of the twentieth century, as well as museum practice and discourse in the mid to late twentieth century, questioning them as knowledge and reading them as cultural constructs. Finally, the thesis brings an archival lens to bear on the collection, and explores the implications of processing the collection as a historical archive as opposed to an ethnographic record of material culture. In order to do this I establish at the outset that the entire collection formed an archive. All its components hold knowledge and need to be read in relation to each other, so that it is important not to isolate, for example, the artefacts from the documents and the photographs because any interpretation of the collection would then be incomplete. Archive theories help problematise the assumption that museum ethnographic collections serve as simple records of a vanished or vanishing lifestyle. These methodologies provide the materials and insights which enable readings of the collection both along and across the grain, processes which draw attention to the cultures of collecting and categorising which lie at the base of many ethnographic collections found in museums today. In addition to being an expression of his melancholy, Fourie’s avocation was very much a part of the process of creating an identity for himself and his fellow colonists. A close reading of the documents reveals that he was constantly confronted with the disastrous effects of colonisation on the Khoisan, but did not do anything about the fundamental cause. On the contrary, he took part in the Administration’s policy-making processes. The thesis tentatively suggests that his avocation became an act of redemption. If he could not save the people (medically or politically), he would create a collection that would save them metonymically. Ironically those who encountered the collection after it left his hands used it to screen out what few hints there were of colonisation. Finally the study leads to the conclusion that the processes of making and institutionalising this archive formed an important part of the creation of the body of ethnography upon which academic and popular perceptions of Khoisan identity have been based over a period of many decades.

Durante os anos de 2013 a 2016, a África do Oeste, mais precisamente a região do Mano River Union Libéria, Serra Leoa e Guiné-Conacri viveu sob uma das piores epidemias do vírus do ebola ocorridas desde 1976, ano do primeiro relato do vírus no antigo Zaire (atual Congo). Entendendo a epidemia como locus privilegiado para a compressão das estruturas de uma sociedade, podendo descortinar conflitos políticos e desigualdades sociais e econômicas, dediquei-me à feitura de uma etnografia na Serra Leoa, durante 9 meses, momento em que morei em Freetown, a capital do país, e também em comunidades rurais. Na medida em que a epidemia neste país matou mais mulheres do que homens, busquei entender o porquê deste fato. Para tanto, segui as histórias de três mulheres mortas por conta do vírus: Jinnah Amana da comunidade de Komende-Luyama, Isha Tullah de Devil Hole e Fatmata de John Thorpe. A partir de um intenso trabalho de campo, concluí que a maior mortandade de mulheres serra-leonenses estava diretamente relacionada ao trabalho do cuidado dispendido a seus familiares e amigos. Deste modo, a epidemia do ebola na Serra Leoa era generificada, colocando mulheres em risco por conta da pesada responsabilização destas perante a trama de parentesco e afetos. Diante disso, cunhei o termo cuidado perigoso como uma categoria boa para pensar as relações de gênero por detrás da epidemia do ebola na Serra Leoa. Portanto, esta pesquisa segue as narrativas reveladoras de mulheres, vivas e mortas, a respeito do ebola na Serra Leoa. Narrativas estas que apontaram para a impossibilidade de se entender a epidemia do Ebola ou qualquer outro fenômeno social da Serra Leoa - sem se acessar as memórias da guerra civil vivida no país durante os anos de 1991 a 2002. / From 2013 to 2016, the West Africa, more precisely the Mano River Union region Liberia, Sierra Leone and Guinea-Conakry went through one of the worst Ebola virus epidemics since 1976, the year when the virus was first reported in Zaire (now, Congo). Understanding the epidemic as a privileged locus to understand the structures of a society, revealing political conflicts and social and economic inequalities, I dedicated myself to do ethnography in Sierra Leone for 9 months, when I lived in Freetown, the capital of the country, but also in rural communities. As the epidemic in this country killed more women than men, I sought to understand why this was occurred. In this way, I followed the stories of three women killed by the virus: Jinnah Amana from Komende-Luyama community, Isha Tullah from Devil Hole and Fatmata from John Thorpe. From an intensive fieldwork, I concluded that the large number of female death in Sierra Leonean was directly related to the work of the care expended on their relatives and friends. Thus, the Ebola epidemic in Sierra Leone was gendered, placing women at risk because of their heavy accountability to the network of kinship and affections. Faced with this, I coined the term \"dangerous care\" as a good category to think about the gender relations behind the ebola epidemic in Sierra Leone. Therefore, this research follows the revealing narratives of women, alive and dead, regarding the ebola in Sierra Leone. These narratives pointed to the impossibility of understanding the Ebola epidemic - or any other social phenomena in Sierra Leone - without accessing the memories of the civil war in the country during the years 1991 to 2002.

Previous research and literature commonly agree to the fact that women, especially rural women, is the most vulnerable group in society. Many of them tend to be found in the poorest sections of society. Women depend on natural resources for their livelihoods and are discriminated concerning labour division and access, control and knowledge about natural resources such as forests. Changes in the climate and natural degradation, especially forest degradation are threatening their livelihoods. Gender relations are structured around managing the environment where women are seen as major users and managers of the forests. The aim and the research questions of this study is to examine how women in Senegal experience that their everyday life and livelihood activities within fuelwood collection have been affected by deforestation. Furthermore, what reason do women see behind deforestation and the changes in their local environments. Semi-structured interviews were conducted with eleven women from two villages in southern Senegal in the region of Casamance and Sine-Saloum. All these women were involved in fuelwood collecting activities. The result of the study was analysed through previous research, feminist political ecology approach and through definitions of livelihood and sustainable development in order to explain women’s experiences and activities within fuelwood collection. The result found that all women experiences changes in their livelihoods because of deforestation. The amount of time spent on fuelwood collecting activities increased while it less time was left to other activities. Women’s income and resources from the forests reduced or disappeared and the main focus turned into cover the needs of the household. Women’s personal everyday lives have been negatively affected by deforestation. Heavy work had negative health effects on the women. Some women have left fuelwood collection for alternative sources of income because it has become too demanding. Furthermore, the results showed that women are worried about their future since they are in mutual need of forests as well as fuelwood to survive.

La rentabilité des filières de production de biocarburants est une condition indispensable à leur compétitivité par rapport aux carburants d’origine fossile. Cette rentabilité dépend de plusieurs facteurs intrinsèques liés aux technologies de transformation ainsi qu’à l’organisation de ces filières.Dans le cadre de cette thèse, nous étudierons plus particulièrement les filières d’approvisionnement en Jatropha curcas, en Balanites aegyptiaca et en tournesol avec pour objectif d’évaluer et d’optimiser les conditions de viabilité de filière de production de biocarburants en Afrique de l’ouest.Partant des filières potentiellement existantes en Afrique de l’ouest, il faudra proposer un modèle permettant de calculer les coûts et les impacts environnementaux des systèmes de production de biocarburants en tenant compte des données géographiques sur les champs, des contraintes de saisonnalité, des contraintes géographiques et de la disponibilité des ressources. Cette étude devra également intégrer l’analyse et l’optimisation d’options technologiques et de procédés de production de biocarburant. Ainsi après avoir défini les critères et indicateurs pertinents de développement durable, il s’agira de : proposer un modèle d’évaluation de ces critères pour les réseaux étudiés en tenant compte des options de valorisation des coproduits ; concevoir un outil multicritère d’évaluation de performances des systèmes de production de biocarburant ; concevoir un outil ou « système d’aide à la décision » pour les décideurs et les acteurs impliqués dans les filières étudiées ; étudier non-seulement les aspects techniques de transformation d’oléagineux en biocarburant, mais surtout d’introduire dans les calculs les coûts des réseaux permettant de produire de la graine, de la transporter jusqu’à l’unité et d’effectuer sa transformation. / The profitability of biofuel production chains is a prerequisite to their competitiveness with fossil fuels. Profitability depends on several intrinsic factors related to processing technology and the organization of these sectors.In this thesis, we will study in particular Jatropha Curcas, Balanites aegyptiaca and sunflower supply chains. The aims are to evaluate and optimize the sustainability conditions of biofuel production chain of in West Africa.Starting by potentially existing chains in West Africa, a model will be proposed to calculate the costs and environmental impacts of biofuel production systems taking into account the geographic data on the fields, seasonal constraints, geographical constraints and the availability of resources. This study will also include the analysis and optimization of technological options and biofuel production processes. Thus after defining the relevant criteria and indicators for sustainable development, it will be: provide an assessment model of these criteria for networks studied taking into account the option of valorization of co-products; design a multicriteria tool in order to evaluate the performance of biofuel production systems; develop a tool or "decision support system" for policy makers and those involved in the studied sectors; study not only the technical aspects of oilseed processing into biofuel, but also introduce into the calculations system, the cost which allows to produce seeds, carry them to the unit, and perform their transformation.