Climate change is undeniable and constitutes one of the major threats of the 21st century. It impacts sectors of our society, usually negatively, and is likely to worsen towards the middle and end of the century. The agricultural sector is of particular concern, for it is the primary source of food and is strongly dependent on the weather. Considerable attention has been given to the impact of climate change on African agriculture because of the continent’s high vulnerability, which is mainly due to its low adaptation capac- ity. Several studies have been implemented to evaluate the impact of climate change on this continent. The results are sometimes controversial since the studies are based on different approaches, climate models and crop yield datasets. This study attempts to contribute substantially to this large topic by suggesting specific types of climate pre- dictors. The study focuses on tropical Africa and its maize yield. Maize is considered to be the most important crop in this region. To estimate the effect of climate change on maize yield, the study began by developing a robust cross-validated multiple linear regression model, which related climate predictors and maize yield. This statistical trans- fer function is reputed to be less prone to overfitting and multicollinearity problems. It is capable of selecting robust predictors, which have a physical meaning. Therefore, the study combined: large-scale predictors, which were derived from the principal component analysis of the monthly precipitation and temperature; traditional local-scale predictors, mainly, the mean precipitation, mean temperature, maximum temperature and minimum temperature; and the Water Requirement Satisfaction Index (WRSI), derived from the specific crop (maize) water balance model. The projected maize-yield change is forced by a regional climate model (RCM) REMO under two emission scenarios: high emission scenario (RCP8.5) and mid-range emission scenario (RCP4.5). The different effects of these groups of predictors in projecting the future maize-yield changes were also assessed. Furthermore, the study analysed the impact of climate change on the global WRSI. The results indicate that almost 27 % of the interannual variability of maize production of the entire region is explained by climate variables. The influence of climate predictors on maize-yield production is more pronounced in West Africa, reaching 55 % in some areas. The model projection indicates that the maize yield in the entire region is expected to decrease by the middle of the century under an RCP8.5 emission scenario, and from the middle of the century to the end of the century, the production will slightly recover but will remain negative (around -10 %). However, in some regions of East Africa, a slight increase in maize yield is expected. The maize-yield projection under RCP4.5 remains relatively unchanged compared to the baseline period (1982-2016). The results further indicate that large-scale predictors are the most critical drivers of the global year-to-year maize-yield variability, and ENSO – which is highly correlated with the most important predictor (PC2) – seems to be the physical process underlying this variability. The effects of local predictors are more pronounced in the eastern parts of the region. The impact of the future climate change on WRSI reveals that the availability of maize water is expected to decrease everywhere, except in some parts of eastern Africa. / Weil die Folgen des Klimawandels die Lebensgrundlagen aller Lebewesen beeinträchtigen, ist der Klimawandel ein sehr relevantes Thema des 21. Jahrhunderts. Seine negativen Effekte betreffen bereits viele Sektoren unserer Gesellschaft und die Prognosen zeigen, dass sich die Auswirkungen des Klimawandels Mitte und Ende dieses Jahrhunderts ver- schärfen werden. Die Landwirtschaft ist besonders betroffen, denn sie ist sehr abhängig vom Klima. Da die Landwirtschaft als Hauptnahrungsquelle der Menschen gilt, ist es erforderlich sich mit den Problemen des Klimawandels rechtzeitig zu beschäftigen, um in der Zukunft die Ernährung der Menschheit gewährleisten zu können. Viele Forscher beschäftigen sich mit den Folgen des Klimawandels in der Landwirtschaft. Besonders in Afrika wurde viel geforscht, weil die Landwirtschaft in Afrika sich technisch schlecht anpassen kann, um die Schwierigkeiten, die mit dem Klimawandel einhergehen, zu über- winden. Mehrere Studien wurden durchgeführt, um die Auswirkungen des Klimawan- dels in Afrika zu bewerten. Aufgrund der unterschiedlichen verwendeten statistischen Methoden, Modellierungen der Umweltprozesse oder Ertragsdaten sind die Ergebnisse teilweise kontrovers. Diese Studie versucht, einen wesentlichen Beitrag zum Einfluss des Klimawandels auf die Landwirtschaft in Westafrika zu leisten, indem sie spezifis- che Methoden vorschlägt, um das Klima der Zukunft projizieren zu können. Diese Studie behandelt Maiserträge in den Tropen Afrikas, da Mais dort die wichtigste Nutzpflanze ist. Um die Auswirkungen des Klimawandels auf den Maisertrag abzuschätzen, wurde ein Regressionsmodell (aus dem Englischen: robust cross-validated multiple) entwickelt, das Klimaprädiktoren und Maiserträge koppelt. Diese entwickelte statistische Übertra- gungsfunktion ist zuverlässiger bei Schwierigkeiten mit der Überanpassung und der Mul- tikollinearität. Außerdem ist sie auch in der Lage robuste Prädiktoren mit physikalischer Bedeutung auszuwählen. Deshalb wurden in der Studie großräumige und lokale Prädik- toren kombiniert. Erstere entstammen der Analyse der Komponenten des monatlichen Niederschlags und der Temperatur, letztere basieren basieren auf den mittleren und Ex- tremtemperaturen sowie dem mittleren Niederschlag. Zusätzlich zu den Prädiktoren wurde ein Index der Wasserbedarfsdeckung (Water Requirement Satisfaction Index, WRSI) verwendet, der auf einem Wasserhaushaltsmodell der Nutzpflanzen basiert. Die erwartete Mais-Ertragsänderung wird mithilfe eines regionalen Klimamodells (RCM) REMO für die Emissionsszenarien RCP8.5 und RCP4.5 simuliert. Die einzelnen Effekte der Prädiktoren- Gruppen bei der Prognose der zukünftigen Mais-Ertragsänderungen wurden ebenfalls bewertet. Darüber hinaus analysierte die Studie die Auswirkungen des Klimawandels auf den WSRI. Durchschnittlich zeigen die Ergebnisse eine jährliche Maisproduktionsän- derung von ca. 27 % in der gesamten Region. Diese Änderung, die in Westafrika mit ca. 55 % stärker ausgeprägt ist, ist eine Folge des Klimawandels. Die Simulationen des Mod- ells anhand von RCP8.5-Emissionsszenario zeigen auch, dass der Maisertrag der gesamten Region voraussichtlich bis Mitte des Jahrhunderts abnehmen wird. Danach findet eine geringe Ertragserhöhung statt, die jedoch um ca. 10 % unter der ursprünglichen Menge liegt. Im Gegensatz zu Westafrika wird in einigen Regionen Ostafrikas wird ein leichter Anstieg des Maisertrags simuliert. Die Mais-Ertragsprognose für die gesamte Region mittels RCP4.5 bleibt relativ unverändert im Vergleich zum ursprünglichen Ertrag. Die Ergebnisse zeigen weiterhin, dass die großräumigen Prädiktoren die wichtigste Rolle bei den globalen jährlichen Maisertragsschwankungen spielen. ENSO ist stark mit dem wichtigsten Prädiktor korreliert, was auf den physikalischen Prozess hinweist, der diese Ertragsänderung erklärt. Die Relevanz der lokalen Prädiktoren ist in den östlichen Re- gionen Afrikas stärker ausgeprägt. Sie beeinflussen den WRSI, sodass der Maisertrag im Verhältnis zur Wasserverfügbarkeit voraussichtlich überall abnehmen wird. Ausgenom- men sind einigen Regionen Ostafrikas.

Rapid population growth in West Africa has led to expansion in croplands due to the need to grow more food to meet the rising food demand of the burgeoning population. These expansions negatively impact the sub-region's ecosystem, with implications for water and soil quality, biodiversity and climate. In order to appropriately monitor the changes in croplands and assess its impact on the ecosystem and other environmental processes, accurate and up-to-date information on agricultural land use is required. But agricultural land use mapping (i.e. mapping the spatial distribution of crops and croplands) in West Africa has been challenging due to the unavailability of adequate satellite images (as a result of excessive cloud cover), small agricultural fields and a heterogeneous landscape. This study, therefore, investigated the possibilities of improving agricultural land use mapping by utilizing optical satellite images with higher spatial and temporal resolution as well as images from Synthetic Aperture Radar (SAR) systems which are near-independent of weather conditions. The study was conducted at both watershed and regional scales. At watershed scale, classification of different crop types in three watersheds in Ghana, Burkina Faso and Benin was conducted using multi-temporal: (1) only optical images (RapidEye) and (2) optical plus dual polarimetric (VV/VH) SAR images (TerraSAR-X). In addition, inter-annual or short term (2-3 years) changes in cropland area in the past ten years were investigated using historical Landsat images. Results obtained indicate that the use of only optical images to map different crop types in West Africa can achieve moderate classification accuracies (57% to 71%). Overlaps between the cropping calendars of most crops types and certain inter-croppings pose a challenge to optical images in achieving an adequate separation between those crop classes. Integration of SAR images, however, can improve classification accuracies by between 8 and 15%, depending on the number of available images and their acquisition dates. The sensitivity of SAR systems to different crop canopy architectures and land surface characteristics improved the separation between certain crop types. The VV polarization of TerraSAR-X was found to better discrimination between crop types than the VH. Images acquired between August and October were found to be very useful for crop mapping in the sub-region due to structural differences in some crop types during this period. At the regional scale, inter-annual or short term changes in cropland area in the Sudanian Savanna agro-ecological zone in West Africa were assessed by upscaling historical cropland information derived at the watershed scale (using Landsat imagery) unto a coarse spatial resolution, but geographically large, satellite imagery (MODIS) using regression based modeling. The possibility of using such regional scale cropland information to improve government-derived agricultural statistics was investigated by comparing extracted cropland area from the fractional cover maps with district-level agricultural statistics from Ghana The accuracy of the fractional cover maps (MAE between 14.2% and 19.1%) indicate that the heterogeneous agricultural landscape of West Africa can be suitably represented at the regional or continental scales by estimating fractional cropland cover on low resolution Analysis of the results revealed that cropland area in the Sudanian Savanna zone has experienced inter-annual or short term fluctuations in the past ten years due to a variety of factors including climate factors (e.g. floods and droughts), declining soil fertility, population increases and agricultural policies such as fertilizer subsidies. Comparison of extracted cropland area from the fractional cover maps with government's agricultural statistics (MoFA) for seventeen districts (second administrative units) in Ghana revealed high inconsistencies in the government statistics, and highlighted the potential of satellite derived cropland information at regional scales to improve national/sub-national agricultural statistics in West Africa. The results obtained in this study is promising for West Africa, considering the recent launch of optical (Landsat 8) and SAR sensors (Sentinel-1) that will provide free data for crop mapping in the sub-region. This will improve chances of obtaining adequate satellite images acquired during the cropping season for agricultural land use mapping and bolster opportunities of operationalizing agricultural land use mapping in West Africa. This can benefit a wide range of biophysical and economic models and improve decision making based on their results. / Das schnelle Bevölkerungswachstum im Westen Afrikas hat, durch das erhöhte Bedürfnis nach Lebensmittel der expandierenden Bevölkerung, zu einer steigenden Lebensmittelnachfrage und damit zur Ausweitung von Ackerland geführt. Diese Expansionen haben negative Einflüsse auf das Ökosystem der Subregion, die Konsequenzen für Wasser- und Bodenqualität, sowie für Biodiversität und das Klima nach sich ziehen. Um die Veränderungen der Ackerflächen überwachen und die Folgen für das Ökosystem und anderer Umweltprozesse richtig abschätzen zu können, werden genaue und aktuelle Informationen über die landwirtschaftliche Nutzung benötigt. Das kartographieren landwirtschaftlicher Flächennutzung (z.B. das Abbilden der räumlichen Verteilung von Feldfrüchten und Ackerflächen) in Westafrika wurde durch die mangelhafte Verfügbarkeit geeigneter Satellitendaten (durch das Auftreten massiver Wolkenbedeckung), der geringen Größe der landwirtschaftlichen Flächen, sowie der heterogenen Landschaft, erschwert. Aus diesen Gründen untersucht diese Studie das Potential landwirtschaftlich genutzte Flächen, durch die Nutzung von optischen Satellitensystemen mit höherer geometrischer und temporaler Auflösung und Aufnahmen des Synthetic Aperture Radar (SAR) als ein nahezu wetterunabhängiges System, aufzunehmen. Diese Studie wurde sowohl auf der Skala von Wassereinzugsgebieten als auch von Regionen erstellt (Agrarökologische Zone in der sudanesischen Savanne). Auf der Skala der Wassereinzugsgebiete wurden Klassifikationen verschiedener Feldfrüchte in drei Einzugsgebieten in Ghana, Burkina Faso und Benin, mithilfe multitemporaler Abbildungen, bestehend aus entweder (1) nur optischer Abbildungen (Rapideye) oder (2) optischer und dual polarimetric (VV/VH) SAR Aufnahmen (TerraSAR-X), durchgeführt. Zusätzlich wurden interannuelle oder kurzzeitige (2-3 Jahre) Veränderungen in der Ausdehnung von Ackerflächen über die vergangenen zehn Jahre hinweg mittels historischer Landsataufnahmen untersucht. Die Ergebnisse zeigen, dass das Kartographieren verschiedener Feldfrüchte in Westafrika durch nur optische Abbildungen eine moderate Klassifikationsgenauigkeit von 57% bis 71% widergibt. Überlappungen zwischen dem Anbauplan der meisten Feldfrüchte und dem Zwischenfruchtanbau stellen eine Herausforderung für optische Abbildungen dar, um eine angemessene Unterscheidung der Feldfrüchte zu erreichen. Die Hinzunahme von SAR Aufnahmen kann die Klassifikationsgenauigkeit, abhängig von der Anzahl verfügbarer Szenen und deren Aufnahmedatum, jedoch um 8% bis 15% erhöhen. Die Empfindlichkeit der SAR Systeme gegenüber unterschiedlichem Aufbau der Fläche von Feldfrüchten und der Charakteristika der Landoberfläche verbesserten die Trennbarkeit unterschiedlicher Feldfrüchte. Wie sich herausstellte hat die VV Polarisation von TerraSAR-X eine bessere Trennung der Feldfrüchte bewirkt als die VH Polarisation. Außerdem zeigt sich, dass Aufnahmen zwischen August und Oktober sehr nützlich zur Abbildung von Feldfrüchten in der Subregion sind, da in dieser Zeit strukturelle Unterschiede einiger Feldfrüchte beobachtet werden können. Auf regionalem Maßstab wurden interanuelle oder kurzzeitige Veränderungen der Ackerflächen in der agrarökologischen Zone der sudanesischen Savanne in Westafrika durch das hochskalieren historischer Informationen zu den Ackerflächen auf der Skala der Wassereinzugsgebiete (aus Landsat Aufnahmen) auf eine gröbere Auflösung, aber geographisch weite Satellitenszene (MODIS), unter Zuhilfenahme eines auf Regression basierenden Modells, berechnet. Die Möglichkeit regionalskalierte Informationen zu Ackerflächen zu nutzen um staatlich erstellte landwirtschaftliche Statistiken zu verbessern wurde untersucht, indem die extrahierte Fläche der Äcker aus fraktionierten Karten zur Landbedeckung mit landwirtschaftlichen Statistiken auf Distrikt-Level miteinander verglichen werden. Die Genauigkeit der fraktionierten Landbedeckungskarten (Mean Absolute Error zwischen 14,2% und 19,1%) weist darauf hin, dass die heterogene Agrarlandschaft Westafrikas auf einem regionalen oder kontinentalen Maßstab, durch die Abschätzung fraktionierter Ackerflächen aus gering aufgelösten Satellitendaten, angemessen repräsentiert werden kann. Die Analyse der Ergebnisse zeigt, dass die Ackerflächen der Agrarökologischen Zone der sudanesischen Savanne interannuelle oder kurzzeitige Schwankungen in den vergangenen zehn Jahren unterlegen waren. Diese Schwankungen ergeben sich durch bestimmte Faktoren wie: klimatische Faktoren (z.B. Überschwemmungen oder Dürren), sinkende Bodenfruchtbarkeit, Bevölkerungswachstum und landwirtschaftliche Politik wie der Subvention von Düngemitteln. Der Vergleich von fraktionierter Landbedeckungskarten mit staatlich erstellten landwirtschaftlichen Statistiken (MoFA) in 17 Distrikten in Ghana ergaben große Unregelmäßigkeiten in den staatlichen Statistiken und zeigten das Potential von aus Satellitendaten abgeleiteten Informationen zu Ackerflächen auf regionalem Maßstab um nationale oder subnationale landwirtschaftliche Statistiken in Westafrika zu verbessern. Angesichts der baldigen Starts der optischen (Landsat 8) und SAR (Sentinel-1) Sensoren, die frei zugängliche Daten für die Kartierung von Feldfrüchten in der Subregion liefern werden, sind die Ergebnisse, die in dieser Studie gewonnen wurden, vielversprechend für Westafrika. Dadurch steigen die Chancen, dass adäquate Satellitenszenen für das Abbilden landwirtschaftlicher Landnutzung während der Anbauzeitraums bezogen und operationalisiert werden können. Dies hat zur Folge, dass ein breites Spektrum biophysikalischer und ökonomischer Modelle davon profitieren und die Entscheidungsfindung durch die Ergebnisse optimiert wird.

Der vielschichtige Begriff Entwicklung stellt die Basis für die multidisziplinäre Entwicklungsforschung, aber auch die Entwicklungspolitik und Entwicklungszusammenarbeit dar und wird demzufolge auf verschiedenste Art und Weise verwendet. Insbesondere zu den Auswirkungen regionaler Entwicklungsprozesse auf lokaler Ebene existieren innerhalb der entwicklungstheoretischen Ideengeschichte eine Vielzahl unterschiedlicher Zugänge, über die die vorliegende Arbeit einen kurzen Überblick gibt. Unter Berücksichtigung anthropogeographischer Ansätze zur Erforschung des Verhältnisses von Entwicklung und Raum werden im ersten (theoretischen) Teil die Konzepte der lokalen Partizipation sowie der Politischen Ökologie als geeignete Analyseinstrumente für das Verständnis konkreter lokaler Entwicklungsprozesse erarbeitet; Entwicklung wird hierbei akteurs- und kontextorientiert als Ergebnis von Mensch-Umwelt-Interaktionen angesehen. Im Rahmen eines case study research wird im zweiten Teil der Arbeit die Praxistauglichkeit dieser Analyseinstrumente überprüft. Hierfür werden in zwei Untersuchungsregionen regionale Entwicklungsdynamiken beschrieben und analysiert, um deren räumliche und soziale Auswirkungen zu verstehen. In beiden Gebieten (Mampu/Mbankana in der Demokratischen Republik Kongo sowie Wasini Island in Kenia) hat in den vergangenen Jahren eine durch unterschiedliche Prozesse verursachte rasante Regionalentwicklung stattgefunden, die die Gebiete jeweils deutlich von ihrem Umland abhebt. Im Fallbeispiel Wasini Island wurde die Entwicklung durch den (internationalen) Tourismus bedingt, in Mampu/Mbankana durch ein Entwicklungsprojekt der Hanns-Seidel-Stiftung (HSS). Für beide Gebiete wird zuerst der naturräumliche, politische und historische Kontext aufgezeigt, welcher die Rahmenbedingungen für die Analyse der einzelnen Akteure und Akteursgruppen darstellt. Sowohl für Wasini Island als auch für Mampu/Mbankana können während des Untersuchungszeitraums Ereignisse identifiziert werden, die von der einheimischen Bevölkerung (bzw. Teilen dieser) als stark situationsverändernd und zudem nicht endogen verursacht wahrgenommen werden (externe Krisen): in Wasini der drastische Einbruch der Touristenzahlen nach den Unruhen im Nachgang der Präsidentschaftswahlen (2007/08 Kenyan Crisis), im kongolesischen Untersuchungsgebiet der schrittweise Rückzug der HSS aus dem operativen Projekt ab 2009 und die damit einhergehende Übertragung von Verantwortung auf lokale Gremien und Organisationen. Durch die Zusammenführung der Ergebnisse aus beiden Fallbeispielen wird konstatiert, dass Entwicklung auf regionaler Ebene als ein kontext- und akteursabhängiger dynamischer Prozess anzusehen ist, der aus den kumulierten, in beide Richtungen wirksamen Mensch-Umwelt-Interaktionen in der betrachteten Region resultiert, und damit in der Tradition geopossibilistischer Perspektiven steht, in denen die natürliche bzw. geographische ebenso wie die gesellschaftliche Umwelt die Rahmenbedingungen für menschliches Handeln und damit Entwicklung vorgibt, jedoch nicht determiniert. / Development as the fundamental concept of Development Studies, Politics and Cooperation is an inhomogeneously used term with a variety of different connotations. This dissertation gives in its theoretical part a short introduction to the history of development thought, focused especially on geographical approaches concerning regional development as well as the relationship between development and space. Thus, local participation and political ecology are identified as suitable instruments for analysing dynamics and actual processes of local development. So the stakeholder- and context-oriented approach leads to development as a result of human-environment interactions. To confirm the usability of the theoretical implications mentioned above, the second part contains a case study research to describe and analyse the regional development and its spatial and social effects in two field study areas. The actual developments in both regions ¬- Wasini Island in Kenya and Mampu/Mbankana in the Democratic Republic of the Congo - are thereby heavily affected by external influences, namely international tourism and nature conservation (Wasini), respectively a development cooperation project carried out by the Hanns Seidel Foundation (Mampu/Mbankana). The analyses also take into account the particular natural-spatial, political and historical context, being the framework for local stakeholders‘ actions. In both study areas events changing the situation can be found, which by large parts of local populations are experienced as exogenous crises: a dramatic decline of tourist arrivals due to the post-electoral riots (2007/08 Kenyan Crisis) in Wasini and the phasing out of Hanns Seidel Foundation‘s financial support in Mampu/Mbankana since 2009, including intraregional shifts of responsibilities and influence. As a result of both the theoretical and empirical findings, development on a regional level is analysed as a stakeholder- and context-dependent process which consists of the accumulated two-way human-environment interactions within a region. This perspective is founded on the tradition of geographical possibilism, because it shows the natural, geographical and social environments framing, but not determining, human actions and thus development processes.

In the 1960s, when most African nations gained their independence after the age of colonialism, several theories and strategies emerged with the goal of "developing" these apparently "underdeveloped" territories. One of the most influential approaches for this task was represented in Julius K. Nyerere´s idea of Ujamaa, the Tanzanian version of African socialism. Even before the Arusha Declaration established Ujamaa as a national development strategy in 1967, several groups of politicized young farmers took to the empty countryside of Tanzania to implement their own version of cooperative development. From one of these attempts emerged the Ruvuma Development Association (RDA), which organized up to 18 villages in southwestern Tanzania. The RDA became the inspiration for Nyerere´s concretization of Ujamaa and its implementation on national level. Yet, the central state could not replicate the success of the peasants, which was based on voluntariness and intrinsic motivation. In 2015, this exploratory study has revisited the Region of Ruvuma. Through a case study approach, relying mostly on qualitative methods, new insights into the local history of Ujamaa and its perception have been gathered. In particular, narrative interviews with contemporary witnesses and group interviews with the present-day farmers’ groups have been conducted. Furthermore, NGOs active within the region, as well as regional and local government institutions were among the key stakeholders identified to concretize the local narrative of Ujamaa development. All interviews were analyzed according to the principles of qualitative content analysis. Additionally, individual villager questionnaires were used to achieve a more holistic picture of the local perception of development, challenges and the Ujamaa era. None of the original Ujamaa groups of the times of the RDA was still operational at the time of research and no case of village-wide organization of collective agriculture could be observed. Nevertheless, in all of the three case study villages, several farmers’ groups (vikundi) were active in organizing development activities for their members. Furthermore, the perception of the Ujamaa era was generally positive throughout all of the case study sites. Yet, there have been significant differences in this perception, based on the village, age, gender and field size of the recipients. Overall, the period of Ujamaa was seen as an inspiration for present-day group activities, and the idea of such activities as a remedy for the developmental challenges of these villages was common among all stakeholders. This thesis concludes that the positive perception of group activities as a vehicle for village development and the perception of Ujamaa history as a positive asset for the inception and organization of farmers’ groups would be highly beneficial to further attempts to support such development activities. However, the limitations in market access and capital availability for these highly-motivated group members have to be addressed by public and private development institutions. Otherwise, "the smell of Ujamaa" will be of little use for the progress of these villages. / In den 1960er Jahren, als die meisten Nationen Afrikas ihre Unabhängigkeit erlangten, entstanden etliche Strategien und Theorien, welche die "Entwicklung" dieser „unterentwickelten“ Territorien zum Ziel hatten. Einer der einflussreichsten Ansätze für dieses Ziel war Julius K. Nyereres Idee von Ujamaa, der tansanischen Variante des afrikanischen Sozialismus. Noch bevor die Arusha Deklaration Ujamaa 1967 als nationale Entwicklungsstrategie verankerte, versuchten sich verschiedene Gruppen junger, politisierter Bauern an ihrer eigenen Version der kooperativen Entwicklung im dünn besiedelten ländlichen Raum Tansanias. Aus einem dieser Versuche ging die Ruvuma Development Association (RDA) hervor, welche bis zu 18 Dörfer im Südwesten des Landes organisierte. Die RDA wurde die Inspiration für Nyereres Konkretisierung von Ujamaa, sowie dessen Umsetzung auf nationaler Ebene. Allerdings war der Zentralstaat nicht in der Lage, den auf Freiwilligkeit und intrinsischer Motivation beruhenden Erfolg dieser einfachen Bauern zu reproduzieren. Die vorliegende explorative Studie wurde 2015 in der Region Ruvuma durchgeführt und konnte durch einen, im wesentlich auf qualitativen Methoden beruhenden, Case-Study Ansatz neue Einblicke in die lokale Ujamaa-Geschichte sowie deren Wahrnehmung sammeln. Insbesondere wurden narrative Zeitzeugeninterviews und Gruppeninterviews mit heutigen Bauerngruppen durchgeführt. Zur Konkretisierung des lokalen Narratives der Ujamaa Entwicklung wurden zudem in der Region aktive NGOs sowie Regional- und Kommunalverwaltung befragt. Alle Interviews wurden mittels qualitativer Inhaltsanalyse ausgewertet. Zusätzlich dienten, an individuelle Dorfbewohner gerichtete, Fragebögen zur Herausarbeitung eines umfassenden Bildes der lokalen Wahrnehmung von Entwicklung, Herausforderungen und der Ujamaa Ära an sich. Keine der ursprünglichen Ujamaa Gruppen war zum Zeitpunkt der Erhebung noch aktiv. Ebenso konnte kein Fall einer das ganze Dorf umfassenden kollektiven Landwirtschaft beobachtet werden – kleinere Bauerngruppen (vikundi) kristallisierten sich dagegen als rezente Form kooperativer Entwicklungsmodelle heraus. Darüber hinaus war die Wahrnehmung der Ujamaa Ära in allen untersuchten Dörfern überwiegend positiv. Jedoch zeigten sich signifikante Unterschiede dieser Wahrnehmung bezüglich des Wohnortes, des Alters, des Geschlechts und der Größe des Feldes der Befragten. Insgesamt wurde die Zeit von Ujamaa als eine Inspiration für heutige gruppenbasierte Entwicklungsaktivitäten gesehen, welche wiederum von allen Akteuren als Möglichkeit zur Überwindung der Entwicklungsprobleme dieser Dörfer gesehen wurden. Diese Dissertation kommt zu dem Schluss, dass die positive Wahrnehmung von Gruppenaktivitäten als ein Instrument zur kommunalen Entwicklung und die Wahrnehmung der Ujamaa Ära als ein positives "Asset" für die Gründung und Organisation von vikundi sehr vorteilhafte Voraussetzungen für weitere Entwicklungsaktivitäten bieten. Allerdings fehlen diesen Gruppen Kapital und Marktzugang. Dies muss von staatlichen wie nichtstaatlichen Entwicklungsorganisationen angegangen werden, andernfalls wird der "smell of Ujamaa" wenig zum Fortschritt in diesen Dörfern beitragen.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Apesar do desenvolvimento de novas drogas antifúngicas e da sua utilização como terapia profilática visando à prevenção de infecções fúngicas invasivas, estas ainda constituem-se num problema emergente, com elevadas taxas de mortalidade. Neste contexto, destaca-se a aspergilose invasiva, uma infecção fúngica oportunista que acomete pacientes com neutropenia profunda e prolongada, principalmente os pacientes com leucemia aguda ou submetidos a transplante de medula óssea. Aspergillus fumigatus, um fungo filamentoso, é o principal agente etiológico da aspergilose invasiva, sendo um patógeno angioinvasivo. As hifas deste fungo são capazes de causar injúria e ativação endotelial, induzindo o endotélio a um fenótipo pró-trombótico, que por sua vez, é mediado pela secreção de citocinas pró-inflamatórias, em especial, o TNF-α. O presente trabalho teve como objetivo estudar a capacidade de cepas mutantes de A. fumigatus em ativar células endoteliais, avaliando o perfil de secreção de citocinas em meio condicionado e a expressão de fator tecidual. Resumidamente, monocamadas confluentes de células endoteliais isoladas da veia umbilical humana foram incubadas com conídios e tubos germinativos de cepas selvagens (Af293 e Ku80) e mutantes (Δugm1, ΔcalA, ΔcrzA, ΔprtT) de A. fumigatus. A taxa de adesão e endocitose destas cepas às monocamadas de HUVEC foi avaliada a partir de um ensaio quantitativo de imunofluorescência diferencial. O perfil cinético de secreção de citocinas foi determinado em meio condicionado das HUVECs, por ensaio de multiplex para IL-6, IL-8 e TNF-α. A ativação endotelial, por sua vez, foi determinada pela expressão de fator tecidual por RT-PCR em tempo real. Os resultados obtidos demonstraram que a mutante para o gene ugm1, responsável por codificar a enzima UDP-galactopiranose mutase, que converte resíduos de galactopiranose a galactofuranose, apresentou um fenótipo hiperaderente às células endoteliais e um estímulo 10 vezes maior à secreção de TNF-α e 2,5 vezes maior a secreção de IL-6, quando comparada a ativação observada para as cepas selvagens. A galactofuranose é um componente importante de glicoconjugados da parede celular de A. fumigatus. Dessa forma, a ausência desse monossacarídeo na célula fúngica leva a um mecanismo compensatório caracterizado por um aumento na expressão de moléculas de galactosaminogalactana na parede celular. De maneira contrária, mutantes para os genes calA e crzA, apresentaram um fenótipo hipoaderente às HUVECs e uma perda na capacidade de induzir a secreção de citocinas e ativar o endotélio. Essas mutantes apresentam deleções que interferem na via de cálcio/calcineurina, responsável por regular a morfogênese e virulência de A. fumigatus, além de apresentarem alterações no conteúdo de beta-1-3 glucana. Já a cepa ΔprtT, mutante para o fator de transcrição prtT que regula a secreção de múltiplas proteases, apresentou um fenótipo de adesão, estímulo e ativação endotelial semelhante ao observado para as cepas selvagens. A comparação entre a capacidade de conídios e tubos germinativos em ativar células endoteliais, corroborou achados anteriores da literatura que reportam que só hifas são capazes de ativar células endoteliais, independentemente da sua viabilidade. Os dados deste estudo permitiram concluir que dentre os componentes de superfície celular de A. fumigatus, os polímeros de galactose, em especial a galactosaminogalactana, parecem ser responsáveis, pelo menos em parte, pelos mecanismos de interação e ativação endotelial. / Besides the emergency of more active and less toxic antifungal agents and the conventional use of antifungal prophylaxis, invasive mold infections have still high mortality rates, especially, invasive aspergillosis (IA). This life-threatening disease is a predominant fungal opportunistic infection for patients with long-term neutropenia, mostly HSCT recipients. Aspergillus fumigatus is the most important species causing IA and is already known as an angioinvasive fungal pathogen. Upon filamentation this fungus can damage and activate human vein endothelial cells (HUVEC) which in turn switch to a pro-thrombotic phenotype. HUVEC activation is known to be mediated by TNF-α once cell-cell contact occurs. The aim of this study was to investigate the endothelial activation ability of several mutants of A. fumigatus. Briefly, HUVECs were infected with germ tubes and conidia of A. fumigatus wild type (WT) Af293 and Ku80 and mutant (Δugm1, ΔcalA, ΔcrzA, ΔprtT) strains and a differential quantitative fluorescence assay performed to determine adhesion and internalization rates. Thus, a kinetic study of secreted pro-inflammatory cytokines and chemokines in HUVEC conditioned medium was achieved by a multiplex immuneassay. The cytokine production was assayed at three time points (4, 8 and 16 hours) using dead germ tubes, and at one time point (16 hours) using dead conidia, for an E:T ratio of 2:1. Additionally, to investigate endothelial activated phenotype, the expression of tissue factor was performed by a real time RT-PCR assay. The ugm1 mutant, which lacks the ugm1 gene encoding UDP-galactopyranose mutase, an enzyme responsible for the conversion of galactopyranose in galactofuranose, showed a hiperadherent phenotype and an increased capability to cause endothelial cell stimulation and activation. This mutant stimulated at least a 10-fold and 2.5-fold increase of TNF-alfa and IL-6 secretion, respectively and 2-fold increase of tissue factor expression by host cells, as compared to WT strains. Galactofuranose is an uncommon 5-membered ring form of galactose and a very important component of glycostructures of the A. fumigatus cell wall. The lack of this monosaccharide in the fungal cell wall leads to a compensatory mechanism characterized by an increment in the galactosaminogalactan expression. In contrast, the calA and crzA mutants, with upstream and downstream dysfunction in the calcium/calcineurin pathway, with alteration in the cell wall β-1,3-glucan content, showed a decrease capacity to adhere to HUVECs and did not induce both the secretion of pró-inflammatory cytokine and activation on endothelial cells. Furthermore, the mutant ΔprtT, witch lacks the transcriptional factor (prtT) that regulates the secretion of multiple proteases, showed the same adhesion and endothelial cell activation phenotype as observed for WT strains. As indicated in previous investigations, our data showed that conidia of A. fumigatus werent able to cause the same endothelial cell cytokine stimulation observed for germ tubes, and that endothelial cell activation is independent on fungal cell viability. Finally, its possible to conclude that the polymers of galactose in the cell wall of A. fumigatus, especially the galactosaminogalactan molecule, seem to be responsible for the endothelial cell interaction mechanisms and activation.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O Aspergillus fumigatus é o principal agente etiológico da aspergilose invasiva, uma infecção fúngica oportunista que acomete, principalmente, pacientes de Unidades Hematológicas, como aqueles com neutropenia profunda e prolongada. Após a filamentação este fungo angioinvasivo é capaz de ativar e causar danos em células endoteliais de veia umbilical humana (HUVEC) que passam a expressar um fenótipo pró-trombótico. A ativação destas células, dependente de contato célulacélula, é mediada por TNF-α e caracterizada pela expressão de moléculas próinflamatórias, como citocinas, quimiocinas e moléculas de adesão. Recentemente, nosso grupo comparou a ativação endotelial de HUVECs desafiadas com cepas selvagens e uma cepa mutante para o gene UGM1. Nestes experimentos a cepa mutante Δugm1, que apresenta um fenótipo de maior produção de galactosaminogalactana (GAG) na parede celular, mostrou um fenótipo hiperadesivo e uma capacidade maior de ativar células endoteliais. Entretanto, os receptores e as vias de sinalização envolvidos nesta ativação permanecem desconhecidos. Assim, o objetivo deste trabalho foi verificar as proteínas envolvidas nestes processos através do estudo das proteínas diferencialmente expressas nas HUVECs após a interação com A. fumigatus, usando a técnica proteômica 2D-DIGE. Brevemente, as HUVECs foram infectadas com tubos germinativos da cepa selvagem (AF293) e da cepa Δugm1 de A. fumigatus. Em seguida, as proteínas foram marcadas com diferentes fluorocromos e separadas por eletroforese bidimensional. A análise quantitativa foi realizada utilizando o software DeCyder. Foram identificadas por MS/MS cinco proteínas diferencialmente expressas, incluindo a galectina-1 e a anexina A2, ambas mais expressas após a interação, sendo a primeira ~25% mais expressa após a interação com a mutante Δugm1. Este trabalho propõe que a galectina-1 poderia ser o receptor endotelial para polímeros de galactose presentes na parede celular do A. fumigatus, e que a Anexina A2 poderia estar envolvida na sinalização intracelular em resposta a este patógeno. No entanto, experimentos complementares, em curso, são necessários para comprovar esta hipótese. / Aspergillus fumigatus is the main etiological agent of invasive aspergillosis, the main opportunistic fungal infection of Hematologial Unitys patients, especially those with long-term neutropenia. Upon filamentation, this angioinvasive fungus can activate and damage the human umbilical vein endothelial cells (HUVEC), which in response switch to a pro-thrombotic phenotype. HUVEC activation is mediated by TNF-α once cell-cell contact occurs. This activation is characterized by the expression of pro-inflammatory molecules such cytokines, chemokines and adhesion molecules. Recently, our group performed the comparison of HUVEC activation upon interaction with a wild type and the UGM1 mutant strains of A. fumigatus. The Δugm1 strain, which presents an increased production of the cell wall galactosaminogalactan, showed a hyper adherent phenotype and an increased capability to cause endothelial cell stimulation and activation, when compared with the wild type strain. The receptors involved in the pathogen-host interaction or the signaling pathways after endothelial activation by A. fumigatus remain unknown. Thus, the aim of this study was to investigate the differentially expressed proteins in HUVECs upon interaction with A. fumigatus, using the 2D-DIGE proteomic approach. Briefly, HUVECs were challenged with germlings of A. fumigatus wild type Af293 and Δugm1 strains and then submitted to protein extraction. The total HUVEC protein extracts were labeled with different CyDyes and fractionated by 2D electrophoresis. Quantitative analysis to determine the differences in protein abundance amongst interacted cells vs. control endothelial cells was performed using the software DeCyder. Five differentially expressed proteins were identified by MS/MS including galectin-1 and annexin A2, both overexpressed after the interaction. These two proteins are described elsewhere to be associated with host-pathogen interaction. Besides, galectin-1 showed an ~25% increase after interaction with the Δugm1 strain and it is plausible that this particular protein could be a putative receptor for galactose-containing polymers of the A. fumigatus cell wall and annexin A2 could be involved in signalizing pathways upon interaction. However, other experimental evidences, under development, are necessary to confirm this hypothesis.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Apesar do desenvolvimento de novas drogas antifúngicas e da sua utilização como terapia profilática visando à prevenção de infecções fúngicas invasivas, estas ainda constituem-se num problema emergente, com elevadas taxas de mortalidade. Neste contexto, destaca-se a aspergilose invasiva, uma infecção fúngica oportunista que acomete pacientes com neutropenia profunda e prolongada, principalmente os pacientes com leucemia aguda ou submetidos a transplante de medula óssea. Aspergillus fumigatus, um fungo filamentoso, é o principal agente etiológico da aspergilose invasiva, sendo um patógeno angioinvasivo. As hifas deste fungo são capazes de causar injúria e ativação endotelial, induzindo o endotélio a um fenótipo pró-trombótico, que por sua vez, é mediado pela secreção de citocinas pró-inflamatórias, em especial, o TNF-α. O presente trabalho teve como objetivo estudar a capacidade de cepas mutantes de A. fumigatus em ativar células endoteliais, avaliando o perfil de secreção de citocinas em meio condicionado e a expressão de fator tecidual. Resumidamente, monocamadas confluentes de células endoteliais isoladas da veia umbilical humana foram incubadas com conídios e tubos germinativos de cepas selvagens (Af293 e Ku80) e mutantes (Δugm1, ΔcalA, ΔcrzA, ΔprtT) de A. fumigatus. A taxa de adesão e endocitose destas cepas às monocamadas de HUVEC foi avaliada a partir de um ensaio quantitativo de imunofluorescência diferencial. O perfil cinético de secreção de citocinas foi determinado em meio condicionado das HUVECs, por ensaio de multiplex para IL-6, IL-8 e TNF-α. A ativação endotelial, por sua vez, foi determinada pela expressão de fator tecidual por RT-PCR em tempo real. Os resultados obtidos demonstraram que a mutante para o gene ugm1, responsável por codificar a enzima UDP-galactopiranose mutase, que converte resíduos de galactopiranose a galactofuranose, apresentou um fenótipo hiperaderente às células endoteliais e um estímulo 10 vezes maior à secreção de TNF-α e 2,5 vezes maior a secreção de IL-6, quando comparada a ativação observada para as cepas selvagens. A galactofuranose é um componente importante de glicoconjugados da parede celular de A. fumigatus. Dessa forma, a ausência desse monossacarídeo na célula fúngica leva a um mecanismo compensatório caracterizado por um aumento na expressão de moléculas de galactosaminogalactana na parede celular. De maneira contrária, mutantes para os genes calA e crzA, apresentaram um fenótipo hipoaderente às HUVECs e uma perda na capacidade de induzir a secreção de citocinas e ativar o endotélio. Essas mutantes apresentam deleções que interferem na via de cálcio/calcineurina, responsável por regular a morfogênese e virulência de A. fumigatus, além de apresentarem alterações no conteúdo de beta-1-3 glucana. Já a cepa ΔprtT, mutante para o fator de transcrição prtT que regula a secreção de múltiplas proteases, apresentou um fenótipo de adesão, estímulo e ativação endotelial semelhante ao observado para as cepas selvagens. A comparação entre a capacidade de conídios e tubos germinativos em ativar células endoteliais, corroborou achados anteriores da literatura que reportam que só hifas são capazes de ativar células endoteliais, independentemente da sua viabilidade. Os dados deste estudo permitiram concluir que dentre os componentes de superfície celular de A. fumigatus, os polímeros de galactose, em especial a galactosaminogalactana, parecem ser responsáveis, pelo menos em parte, pelos mecanismos de interação e ativação endotelial. / Besides the emergency of more active and less toxic antifungal agents and the conventional use of antifungal prophylaxis, invasive mold infections have still high mortality rates, especially, invasive aspergillosis (IA). This life-threatening disease is a predominant fungal opportunistic infection for patients with long-term neutropenia, mostly HSCT recipients. Aspergillus fumigatus is the most important species causing IA and is already known as an angioinvasive fungal pathogen. Upon filamentation this fungus can damage and activate human vein endothelial cells (HUVEC) which in turn switch to a pro-thrombotic phenotype. HUVEC activation is known to be mediated by TNF-α once cell-cell contact occurs. The aim of this study was to investigate the endothelial activation ability of several mutants of A. fumigatus. Briefly, HUVECs were infected with germ tubes and conidia of A. fumigatus wild type (WT) Af293 and Ku80 and mutant (Δugm1, ΔcalA, ΔcrzA, ΔprtT) strains and a differential quantitative fluorescence assay performed to determine adhesion and internalization rates. Thus, a kinetic study of secreted pro-inflammatory cytokines and chemokines in HUVEC conditioned medium was achieved by a multiplex immuneassay. The cytokine production was assayed at three time points (4, 8 and 16 hours) using dead germ tubes, and at one time point (16 hours) using dead conidia, for an E:T ratio of 2:1. Additionally, to investigate endothelial activated phenotype, the expression of tissue factor was performed by a real time RT-PCR assay. The ugm1 mutant, which lacks the ugm1 gene encoding UDP-galactopyranose mutase, an enzyme responsible for the conversion of galactopyranose in galactofuranose, showed a hiperadherent phenotype and an increased capability to cause endothelial cell stimulation and activation. This mutant stimulated at least a 10-fold and 2.5-fold increase of TNF-alfa and IL-6 secretion, respectively and 2-fold increase of tissue factor expression by host cells, as compared to WT strains. Galactofuranose is an uncommon 5-membered ring form of galactose and a very important component of glycostructures of the A. fumigatus cell wall. The lack of this monosaccharide in the fungal cell wall leads to a compensatory mechanism characterized by an increment in the galactosaminogalactan expression. In contrast, the calA and crzA mutants, with upstream and downstream dysfunction in the calcium/calcineurin pathway, with alteration in the cell wall β-1,3-glucan content, showed a decrease capacity to adhere to HUVECs and did not induce both the secretion of pró-inflammatory cytokine and activation on endothelial cells. Furthermore, the mutant ΔprtT, witch lacks the transcriptional factor (prtT) that regulates the secretion of multiple proteases, showed the same adhesion and endothelial cell activation phenotype as observed for WT strains. As indicated in previous investigations, our data showed that conidia of A. fumigatus werent able to cause the same endothelial cell cytokine stimulation observed for germ tubes, and that endothelial cell activation is independent on fungal cell viability. Finally, its possible to conclude that the polymers of galactose in the cell wall of A. fumigatus, especially the galactosaminogalactan molecule, seem to be responsible for the endothelial cell interaction mechanisms and activation.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O Aspergillus fumigatus é o principal agente etiológico da aspergilose invasiva, uma infecção fúngica oportunista que acomete, principalmente, pacientes de Unidades Hematológicas, como aqueles com neutropenia profunda e prolongada. Após a filamentação este fungo angioinvasivo é capaz de ativar e causar danos em células endoteliais de veia umbilical humana (HUVEC) que passam a expressar um fenótipo pró-trombótico. A ativação destas células, dependente de contato célulacélula, é mediada por TNF-α e caracterizada pela expressão de moléculas próinflamatórias, como citocinas, quimiocinas e moléculas de adesão. Recentemente, nosso grupo comparou a ativação endotelial de HUVECs desafiadas com cepas selvagens e uma cepa mutante para o gene UGM1. Nestes experimentos a cepa mutante Δugm1, que apresenta um fenótipo de maior produção de galactosaminogalactana (GAG) na parede celular, mostrou um fenótipo hiperadesivo e uma capacidade maior de ativar células endoteliais. Entretanto, os receptores e as vias de sinalização envolvidos nesta ativação permanecem desconhecidos. Assim, o objetivo deste trabalho foi verificar as proteínas envolvidas nestes processos através do estudo das proteínas diferencialmente expressas nas HUVECs após a interação com A. fumigatus, usando a técnica proteômica 2D-DIGE. Brevemente, as HUVECs foram infectadas com tubos germinativos da cepa selvagem (AF293) e da cepa Δugm1 de A. fumigatus. Em seguida, as proteínas foram marcadas com diferentes fluorocromos e separadas por eletroforese bidimensional. A análise quantitativa foi realizada utilizando o software DeCyder. Foram identificadas por MS/MS cinco proteínas diferencialmente expressas, incluindo a galectina-1 e a anexina A2, ambas mais expressas após a interação, sendo a primeira ~25% mais expressa após a interação com a mutante Δugm1. Este trabalho propõe que a galectina-1 poderia ser o receptor endotelial para polímeros de galactose presentes na parede celular do A. fumigatus, e que a Anexina A2 poderia estar envolvida na sinalização intracelular em resposta a este patógeno. No entanto, experimentos complementares, em curso, são necessários para comprovar esta hipótese. / Aspergillus fumigatus is the main etiological agent of invasive aspergillosis, the main opportunistic fungal infection of Hematologial Unitys patients, especially those with long-term neutropenia. Upon filamentation, this angioinvasive fungus can activate and damage the human umbilical vein endothelial cells (HUVEC), which in response switch to a pro-thrombotic phenotype. HUVEC activation is mediated by TNF-α once cell-cell contact occurs. This activation is characterized by the expression of pro-inflammatory molecules such cytokines, chemokines and adhesion molecules. Recently, our group performed the comparison of HUVEC activation upon interaction with a wild type and the UGM1 mutant strains of A. fumigatus. The Δugm1 strain, which presents an increased production of the cell wall galactosaminogalactan, showed a hyper adherent phenotype and an increased capability to cause endothelial cell stimulation and activation, when compared with the wild type strain. The receptors involved in the pathogen-host interaction or the signaling pathways after endothelial activation by A. fumigatus remain unknown. Thus, the aim of this study was to investigate the differentially expressed proteins in HUVECs upon interaction with A. fumigatus, using the 2D-DIGE proteomic approach. Briefly, HUVECs were challenged with germlings of A. fumigatus wild type Af293 and Δugm1 strains and then submitted to protein extraction. The total HUVEC protein extracts were labeled with different CyDyes and fractionated by 2D electrophoresis. Quantitative analysis to determine the differences in protein abundance amongst interacted cells vs. control endothelial cells was performed using the software DeCyder. Five differentially expressed proteins were identified by MS/MS including galectin-1 and annexin A2, both overexpressed after the interaction. These two proteins are described elsewhere to be associated with host-pathogen interaction. Besides, galectin-1 showed an ~25% increase after interaction with the Δugm1 strain and it is plausible that this particular protein could be a putative receptor for galactose-containing polymers of the A. fumigatus cell wall and annexin A2 could be involved in signalizing pathways upon interaction. However, other experimental evidences, under development, are necessary to confirm this hypothesis.

Stadterneuerung in Ghana ist seit Jahren auch durch den Widerstand von Bürgerinnen und Bürgern geprägt. Auf der Grundlage einer qualitativen Analyse und Fallstudie zur Sanierung von Marktinfrastrukturen in Kumasi und Cape Coast zeigt diese kumulative Dissertation, dass es zum besseren Verständnis der Ursachen von zivilem Widerstand insbesondere Aufmerksamkeit für die Qualität der Governance-Prozesse selbst bedarf. Marktsanierungsprojekte in Ghana sind durch fünf Prozessphasen geprägt: Scoping, Planung, Finanzierung, Standortverlagerung und -zuweisung. In allen Phasen lassen sich jeweils anders gelagerte Kombinationen aus staatlichen Praktiken des Klientelismus und Neoliberalismus, des Aktivismus nichtstaatlicher Akteure sowie externer, globale und entwicklungsorientierter Investitionspraktiken internationaler und bilateraler Agenturen beobachten. In jeder Phase der Stadterneuerung spiegeln sich städtische Governance-Politiken, auf die wiederum stadt-politische Akteure mit Interventionen reagieren, um diesen Politiken entgegen zu wirken. Konzeptionell trägt die vorliegende Studie zu verschiedenen Diskursen bei: eine multidimensionale analytische Rahmung der geographischen Handelsforschung mit Fokus auf Märkte; eine Betrachtung von Aktivismus als zusätzlicher Dimension der städtischen Governance; die Auseinandersetzung mit politisch induzierter Verdrängung durch staatliche Handlungsweisen als alternativem Konstrukt zur Analyse von marktinduzierten Verdrängungsprozessen; und einen Beitrag zu Debatten um städtische Effekte ausländischer Direktinvestitionen. Die Ergebnisse können integrative Stadtentwicklung und eine nachhaltige Existenzgrundlage urbanen Zusammenlebens im anglophonen Westafrika fördern. Weitere Forschung wird empfohlen, um ein Verständnis für die Governance-Prozesse und die Dynamiken städtischer Infrastrukturentwicklung in der Subregion zu generieren. / Citizen resistance has characterized urban regeneration in Ghana for many years. Previous studies have indicated that resistance against urban regeneration is caused by non-payment of compensation, lack of participation and the failure of the state to provide relocation sites. Through a qualitative analysis of market redevelopment in Kumasi and Cape Coast, this dissertation argues that we should pay more attention to the politics and activism rooted in the urban governance processes, if we are to understand citizen resistance against urban regeneration in Ghana. Market infrastructural redevelopment in Ghana are implemented through the process of scoping, planning, financing, relocation and allocation. This process is shaped by an interplay of internal state practices of clientelism and neoliberalism and activism of non-state actors, as well as external practices of globalization and development funding by international and bilateral agencies. Every stage of the redevelopment process mirrors the politicized nature of urban governance and citizen intervention by way of activism for changing urban governance. Theoretically, this dissertation contributes a multidimensional analytical framework to marketplace research; activism as an additional dimension of urban governance; politically-induced displacement as an alternative construct for analyzing displacement processes; and to the urban debates around Chinese infrastructure finance. The wider implications of the findings of the study for market redevelopment and urban governance in Anglophone West Africa are discussed. Further research is recommended to provide an understanding of the governance processes and dynamics of other forms of urban infrastructural development taking place in the sub-region.

Notre étude porte sur le potentiel de développement durable du tourisme de santé en Libye. Elle tente d’expliquer la différence entre le tourisme médical et le tourisme de santé dont les ressources naturelles et humaines sont une véritable richesse. Notre problématique de recherche part du constat qu’en Libye, le tourisme de santé pourrait contribuer au développement économique du pays et participer pleinement à une perspective de développement durable, du fait qu’il comporte moins d'effets négatifs sur l’environnement et la population. En effet, depuis 54 ans, l'économie libyenne dépend du pétrole. C’est pour cette raison que nous pensons que le développement durable du tourisme de santé est l'une des alternatives les plus importantes qui permettrait de diversifier les ressources financières à court et moyen terme en enrichissant progressivement l’économie du pays à long terme. Les enjeux de notre recherche s’articulent, donc, autour de trois aspects : écologique, économique et social. Notre objectif consiste à découvrir les ressources naturelles et humaines du pays pour envisager la possibilité de développer durablement le tourisme de santé de façon à ce qu’il ne soit pas uniquement rentable économiquement, mais que les conséquences écologiques ne dépassent pas le seuil tolérable. Sans être en contradiction avec les aspects sociaux, il devrait fonder le développement sur le respect réciproque entre le touriste et la société hôte ; dévoiler les obstacles qu'affronte le tourisme en Libye ; attirer l’attention des responsables libyens sur les ressources touristiques et les moyens de les exploiter ; enrichir la bibliographie francophone qui manque d'études géographiques sur la Libye, en général, et dans le domaine du tourisme de santé en Libye en particulier. Afin de répondre à la problématique de notre ce travail, nous posons six questions : la Libye dispose-t-elle de potentialités touristiques ? Quelles sont ses potentialités en tourisme de santé ? Les Européens ont-ils besoin de se soigner par des méthodes naturelles ? Qu’espèrent-ils trouver en Libye ? Jusqu’à quel point accepteraient-ils les conditions imposées par la société libyenne ? L’État libyen est-il crédible dans sa volonté de mise en oeuvre de développer le tourisme ? L’objectif de cette étude consiste à découvrir les éléments du tourisme et du tourisme de santé en Libye. Afin de confirmer cela, la méthodologie suivie part de deux types de démarche : déductive puis inductive. La première démarche nous a permis d’opérer des relations entre différentes variables puis de les appliquer à l’étude d’un certain nombre d’observations. Grâce à la deuxième démarche, nous avons pu généraliser les résultats obtenus sur les cinq pays de notre échantillon de recherche que sont la France, l’Allemagne, l’Italie, l’Espagne, et le Royaume-Uni, démarche qu’il est possible de généraliser sur le reste des habitants de l’Union Européenne. Pour prendre connaissance du problème et tenter de déterminer la possibilité de réussite et de continuité du tourisme de santé, nous avons mené une large enquête à travers le territoire libyen. D’abord, les questionnaires (support de l’entretien, interviews et échantillons) distribués ont touché les habitants des trois provinces importantes de la Libye : Cyrénaïque, Tripoli et Fezzan. Ainsi, près de 10.000 Km ont été parcourus pour rencontrer un maximum d’informateurs. Ensuite, nous avons réalisé des entretiens avec certains responsables du secteur. Enfin, des analyses chimiques ont été effectuées sur les eaux des lacs des régions citées. À l’issue de cette recherche, les résultats préliminaires obtenus jusque là et qui sont en cours de finalisation peuvent être très satisfaisants eu égard à la problématique posée au départ. / This study focuses on sustainable development potential in the health tourism industry in Libya. It attempts to explain the difference between medical tourism and health tourism, for which the country’s natural and human resources are a veritable wealth. Our research begins with the realisation that health tourism in Libya may contribute to the economic development of the country and participate in long-term sustainable development inasmuch as it has fewer negative effects on the environment and the population. Indeed, for the last 54 years the Libyan economy has been dependent on oil. For this reason and others, we believe that sustainable development in the health tourism field is one of the important alternatives available to diversify financial resources in the short and medium terms and for a progressive long-term replacement of petroleum resources as a source of it come for the country. The challenge in our research is found in three axes: ecological, economic and social. Our objective is to identify the country’s natural and human resources so as to sustainably develop health tourism in such a way that it is not only economically profitable, but that its ecological impact remains within tolerable limits. Development must take place with reciprocal respect between the tourist and the host society and not in contradiction with Libyan society. Our research is also aimed at lifting the veil from the obstacles which confront tourism in Libya today and to draw the attention of Libyan authorities to the country’s touristic resources and to the means necessary to exploit them. Finally, we hope to enrich the French language bibliographic corpus on this subject as few geographical studies are available in French pertaining to Libya in general, and pertaining to health tourism in Libya in particular. To examine this area of problems, we ask six questions : - Does Libya dispose of sufficient touristic resources? - Does the country have sufficient resources for health tourism? - What indicates that Europeans are looking for treatment via natural methods? - What do they hope to find in Libya? - To what extent would visitors from the European Union accept the conditions imposed by Libyan society? - Is the Libyan state sufficiently credible in its quest to develop tourism? The objective of our study is to identify the components of tourism and of health tourism in Libya. In order to meet this challenge, we propose a methodology that includes two approaches, deductive and inductive. The first allowed us to establish relationships between different variables and to use them in the study of certain observations. With the second approach, we generalised our findings and applied them to the five countries of our research sampling: France, Germany, Italy, Spain and the United Kingdom, an approach that could be applied to the rest of the European Union. Now, at the end of this investigation, the preliminary results obtained so far are being finalised and appear to be satisfactory with respect to the initial area of study. Indeed, our research could be the first of its kind in Libya. The existence of a touristic potential based on natural resources and the importance of sustainable development in Libya constitute the primary elements of this research. The seriousness of Libya in its development of tourism is yet another parameter that could be just as promising.