Då de flesta människor i Västafrika, framför allt de som bor innanför kustzonen, livnär sig på jordbruk så är pålitliga väderprognoser och säsongsförutsägelser ett viktigt hjälpmedel i det dagliga arbetet och planeringen. I den här rapporten har en litteraturstudie gjorts för att öka kunskapen om de komplexa, både lokala och storskaliga, väderfenomen som ger upphov till nederbörd i området.   Klimatet i Västafrika, ett område som mestadels täcks av regnskog eller savann, präglas av den västafrikanska monsunen som ger regnperiod under norra halvklotets sommar och torrperiod på vintern. Denna monsun visar på stor årlig variation när det gäller dess inledande faser, och prognoser som kan förutsäga dess början är nödvändigt när en jordbrukare ska planera säsongens verksamhet. Av många bidragande faktorer framgår det tydligt att ytvattentemperaturen i Guineabukten är en av de viktigaste parametrarna för monsunens startskede. Den intertropiska konvergenszonen, ITCZ, betraktas som monsunens nordligaste del och denna konvergenszon gör en plötsligt och relativt snabb förflyttning norrut, i fortsättningen benämnd som språnget, över ca 5 breddgrader, vilket av många ses som starten på regnperioden. En tillfällig tryckgradient som uppstår på grund av en tillfällig men skarp temperaturgradient är den bakomliggande orsaken till detta språng. Den i särklass viktigaste processen som ger upphov till regn i Västafrika är konvektion och även om mycket konvektiv nederbörd faller i samband med monsunen så uppstår det även många lokala och mesoskaliga konvektiva system inom monsunen, framförallt kopplat till ostliga vågor. / Since most people in West Africa, particularly those who live away from the shore, work within agriculture, reliable weather forecasts are important in the daily work. In this report, a literature study has been conducted to increase the knowledge about the complex and local weather phenomenon that causes rain.   West Africa is dominated by rainforest and savannah, and the climate is characterized by the West African monsoon which gives rise to a wet season in the northern hemisphere summer and a dry season during the winter. The monsoon shows wide annual variability in its initial stages and forecasts that can predict its beginning is necessary to the farmers who have to decide when and what to plant. Out of many contributing factors, the sea surface temperature seems to be one of the main parameters that have an impact on the starting stage of the monsoon. The inter tropical convergence zone, ITCZ, is regarded as the northernmost part of the monsoon and it makes a sudden and relatively quick jump over about 5 degrees latitude, which is widely regarded as the start of the rainy season. A temporary pressure gradient caused by differences in temperature adjacent to the ITCZ is the reason for this jump. The dominant process that causes rainfall in West Africa is convection. Although a lot of convective precipitation falls in connection with the northern part of the monsoon, convective systems can appear inside the monsoon flow, often linked to African easterly waves.

Alors que des stratégies ont été développées par les pouvoirs publiques qui officiaient à Dakar depuis les années 1920 pour contenir l’évolution de la tuberculose, maladie sociale alors identifiée comme constituant un obstacle aux projets socio-politiques et économique de la France en Afrique de l’ouest, cette maladie continuait en 2019, environ 40 ans après la décolonisation du Sénégal, à figurer parmi les préoccupations des autorités sanitaires de la ville. Se posent dès lors plusieurs questions: pourquoi, en dépit de l’existence d’un vaccin antituberculeux depuis les années 1920 et malgré la découverte de médicaments spécifiques au cours des années 1940-1950, la tuberculose continue de défier les plans mis en œuvre à Dakar pour contenir son évolution? Quels ont été les moyens mobilisés pour stopper son évolution? La lutte contre la tuberculose à Dakar impliquait-elle une action sur les facteurs qui favorisaient l’extension de la maladie? Serait-ce l’exécution des mesures antituberculeuses qui était défaillante? L’hypothèse qui sous-tend cette thèse est que la lutte contre la tuberculose ne constituait pas une priorité pour les autorités sanitaires de Dakar mais aussi que l’inadéquation des différentes mesures préventives et curatives opposées à cette maladie explique les limites de l’action jusque-là entreprise et, par conséquent, sa persistance dans cette ville. À travers une évaluation de l’organisation et de l’exécution des différentes mesures qui ont été prises depuis 1924, ce travail de recherche tente de faire la lumière sur les facteurs explicatifs de la persistance de la tuberculose à Dakar jusqu’en 1969 et d’identifier des continuités, et pas seulement des ruptures, entre la période coloniale et nationale pour mieux saisir la place actuelle de la maladie infectieuse au pays. Ce travail envisage aussi de voir en référence à quels savoirs et à quelles pratiques ont été opérés les choix concernant les mesures à opposer à la tuberculose. Il cherche également à étudier les modalités d’exécution des différentes mesures arrêtées pour stopper le développement de cette maladie afin de saisir les distances entre les intentions et les gestes posés. Pour évaluer l’incidence des différents plans de lutte mis en œuvre contre la tuberculose à Dakar dans la durée choisie, une attention est enfin portée à leur réception ainsi que les attitudes qu’elles ont suscitées chez la population dakaroise. / While strategies had been developed by the public authorities that had been operating in Dakar since the 1920s to contain the spread of tuberculosis, a social disease then identified as an obstacle to France's socio-political and economic projects in Dakar and West Africa, in 2019, some 40 years after Senegal's decolonization, the disease continued to be a concern for the city's health authorities. This raises several questions: Why, despite the manufacture of an anti-tuberculosis vaccine since the 1920s and the discovery of specific drugs in the 1940s and 1950s, tuberculosis continues to defy the plans implemented in Dakar to contain its spread? What has been done to halt its spread? Did the fight against tuberculosis in Dakar also involve action on the factors that contributed to the spread of the disease? Was it the implementation of TB control measures that was failing? The hypothesis underlying this thesis is that the fight against tuberculosis was not a priority for Dakar health authorities, but also that the inadequacy of the various preventive and curative measures against this disease explains the limits of the action taken so far and, consequently, the persistence of tuberculosis in this city. Through an evaluation of the organization and execution of the various measures taken since 1924, this thesis attempts to shed light on the factors explaining the persistence of tuberculosis in Dakar until 1969 and to identify continuities, and not only breaks, between the colonial and national periods in order to better understand the current place of the infectious disease in the country. It also envisages seeing with reference to what knowledge and practices were maked choices concerning measures to combat tuberculosis and seeks to study the modalities of implementation of the various measures adopted to halt the development of this disease in order to grasp distances between intentions and actions taken. In order to assess the impact of the various plans to combat tuberculosis in Dakar over the chosen period, attention is also paid to their reception and the attitudes that they have aroused among the population of Dakar.

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Carnivore are undoubtedly among the most threatened of the mammal species in Africa because of the low density at which they occur and their large home range requirements that do not match with human propensity to develop and alter wildlife habitat. However, the degree of threat is unevenly distributed within the continent, with western and central African carnivores being the most threatened and the least studied. I estimated population size, density, and proportion of area occupied in relation to environmental factors of one medium-size (serval – Leptailurus serval) and two large carnivores (lion – Panthera leo and leopard – P. pardus) in the Niokolo Koba National Park, Senegal, West Africa, using remote camera surveys and both traditional (CR), spatially explicit capture-recapture (SECR) techniques for servals and leopards, and non-spatial (MR) and spatial mark resight (SMR) methods for lions. Lions selected optimal sites with both high tree density and prey activity; leopards occupied areas with high tree density but with less prey activity; and servals selected habitats with more dense canopy cover where leopards were absent. The presence of lions was favorable to serval presence, as we presume leopards avoid lions, although we did not have strong evidence to support it. Moreover, the half mean maximum distance moved (½ MMDM) method under CR methods appeared to overestimate leopard and serval density while full MMDM estimates were close to SECR methods density estimates. For lions, both ½ MMDM and full MMDM methods in MR framework overestimated density whereas the SMR method resulted in more reasonable estimates, especially in light of previous assessments of lion densities in West Africa.. These results are of high importance for conservation and management purposes of the imperiled Niokolo Koba carnivore community. / Master of Science

<p dir="ltr">The Leatherback Sea Turtle (<i>Dermochelys coriacea</i>) is a globally vulnerable species suffering from declining populations due to anthropogenic pressures. There are seven recognized Leatherback Sea Turtle regional management units; however, the Southeast Atlantic unit is considered data deficient. Bioko Island, Equatorial Guinea, is a primary nesting rookery for the Southeast Atlantic regional management unit and has some of the world’s highest numbers of nesting Leatherback Sea Turtles. Despite Bioko Island’s importance to the species, little is known about the nesting ecology or post-nesting migratory movement and behaviors of its nesting Leatherback Sea Turtles. Here, I present the findings of two individual research projects on the nesting ecology of Leatherback Sea Turtles on Bioko Island. First, I explored the long-term clutch success rates (i.e., hatching success and emergence success) of <i>in situ</i> Leatherback Sea Turtle nests on Bioko and searched for associated variables. I found significant spatiotemporal variation over nine nesting seasons, likely driven by individual beach characteristics rather than regional climate patterns. Secondly, I described a novel effort to use solar-reliant towable transmitters to track the post-nesting migratory movements and behaviors of Leatherback Sea Turtles nesting on Bioko Island. With the results from each project, I make recommendations to further the current conservation and research initiatives of Leatherback Sea Turtles.</p>