No description available.

Rural electrification has been a long-standing objective in many developing countries. For decades, the assumption and practice has been to build centralised generating capacity and transmit the electricity over national grids. More recently, interest has grown in using PV (photovoltaic) technology as a solution to the problem of rural electrification. A private household market for PV has been developing in Kenya since 1984 and now has more than 200,000 systems installed, sold through this private market. Consequently, it is widely hailed as a success story among developing countries. Until recently, Tanzania had almost no household PV market, despite interest from a number of actors, including some of those who have been involved in enabling the rapid growth of the market in Kenya. However, sales of PV began to grow quite rapidly from the early 2000s and the trend appears to be gaining pace, with an estimated 285 kWp sold in 2007, having risen by 57% in one year. At the time of the research, there were two large donor-funded PV projects underway in the country. The research attempts to explain the dynamics of the two PV niches over the past 25 years using strategic niche management as its theoretical framework. It finds that the Kenyan niche has benefited more from donor support than is usually acknowledged. The thesis also makes theoretical and methodological contributions. It offers a way to connect first and second-order learning to expectations and visions concepts; dimensions expectations and visions; and presents a tool for systematic investigation of socio-technical trajectory developments. The thesis also suggests a number of ways in which the strategic niche management framework could be enhanced. These include stronger theorising about learning, and the incorporation of power, politics and risk into the theory.

Small scale protected zones are valuable for helping the health and productivity of fisheries at Lake Tanganyika (East Africa). Spatial placement of protected areas relies on accurate maps of benthic habitats, consisting of detailed bathymetry data and information on lake-floor substrates. This information is unknown for most of Lake Tanganyika. Fish diversity is known to correlate with rocky substrates in ≤ 30 m water depth, which provide spawning grounds for littoral and pelagic species. These benthic habitats form important targets for protected areas, if they can be precisely located. At the NMVA, echosounding defined the position of the 30-m isobath and side-scan sonar successfully discriminated among crystalline basement, CaCO3-cemented sandstones, mixed sediment, and shell bed substrates. Total area encompassed from the shoreline to 30 m water depth is ~21 km2 and the distance to the 30-m isobath varies with proximity to deltas and rift-related faults. Total benthic area defined by crystalline basement is ~1.6 km2, whereas the total area of CaCO3-cemented sandstone is 0.2 km2. Crystalline basement was present in all water depths (0-30 m), whereas CaCO3-cemented sandstones were usually encountered in water ≤ 5 m deep. Spatial organization of rocky substrates is chiefly controlled by basin structure and lake level history.

My doctoral thesis challenges the traditional paradigm of phosphorus (P) limitation of phytoplankton communities in freshwaters by suggesting colimitation of P, nitrogen (N), and iron (Fe) in Great Lakes. Oceanographers have recognized Fe, N and P colimitation, and biomass response to Fe is documented in freshwater lakes. I studied African and North American Great Lakes that are similar to large inland oceans. I discovered that Fe is a key nutrient that is often limiting in the offshore, and may explain the dominance of cyanobacteria in nutrient enriched lakes. I also discovered that the nearshore and offshore areas of these large lakes are very different, particularly when invasive dreissenid mussels are impacting the nearshore, as seen in the eastern basin of Lake Erie. As a result of the dreissenids, chlorophyll a (chla) concentrations are significantly lower in the nearshore of Lake Erie, but higher in the nearshore in the three African Great Lakes, as well as pre-dreissenid Lake Erie. The objective of my thesis was to determine the limiting nutrient(s) to the phytoplankton of the Great Lakes Erie, Malawi, Tanganyika, and Victoria in both the nearshore and offshore by measuring the physiological status of the phytoplankton. I also examined how dreissenids affect the distribution of seston and nutrient concentrations between the nearshore and offshore of the eastern basin of Lake Erie. My study design included temporal and spatial surveys in the nearshore and offshore of the four lakes, in which I used a variety of nutrient limitation indicators for P (C:P, N:P, P debt, APA, Fv/Fm), N (C:N, NH4 debt, NO3 debt, Fv/Fm), and Fe (Fv/Fm), as well as photosynthetic efficiency (Fv/Fm) experiments. Nutrient enrichment experiments were also conducted in the nearshore and offshore of the eastern basin of Lake Erie which involved the addition and removal of Fe alone, as well as in combination with P and/or N. Lake Erie nutrient enrichment experiments provided evidence for P, N and Fe colimitation where the addition of Fe with P relieved Fe and P limitation and allowed nitrate (NO3-) assimilation, alleviating N limitation. However, the offshore experiments indicated stronger Fe limitation than the nearshore experiment. Lower chla concentrations in the post-dreissenid nearshore of the eastern basin of Lake Erie may not be due entirely to lower phytoplankton biomass, as photoacclimation of the phytoplankton may also be occurring. Dreissenid grazing effects can be seen in the distribution of dissolved nutrient concentrations between the nearshore and offshore of post-dreissenid Erie. The African Great Lakes are threatened by expanding human populations, resulting in increased nutrient runoff; the consequences of which will depend on the limiting nutrient(s). I found that the nearshore regions of Lakes Malawi and Tanganyika were colimited by N and P, while the offshore regions were colimited by N, P and Fe. The nearshore of Lake Victoria was colimited by light and N, while the offshore was colimited by N, P and Fe. Fe limitation only occurs in the offshore, and positive, significant relationships were found between total dissolved Fe concentrations and cyanobacteria. Continued P and Fe loading to the lakes will create a higher N demand that will result in a shift to N2-fixing cyanobacteria, which has serious consequences to human and ecosystem health as they are a poor nutritive food source and some are potentially toxigenic. The majority of studies conducted on Great Lakes involve offshore sampling, however, the less understood nearshore is where human impacts and activities are concentrated. I discovered there are significant differences between the nearshore and offshore, which has implications for water quality monitoring.

My doctoral thesis challenges the traditional paradigm of phosphorus (P) limitation of phytoplankton communities in freshwaters by suggesting colimitation of P, nitrogen (N), and iron (Fe) in Great Lakes. Oceanographers have recognized Fe, N and P colimitation, and biomass response to Fe is documented in freshwater lakes. I studied African and North American Great Lakes that are similar to large inland oceans. I discovered that Fe is a key nutrient that is often limiting in the offshore, and may explain the dominance of cyanobacteria in nutrient enriched lakes. I also discovered that the nearshore and offshore areas of these large lakes are very different, particularly when invasive dreissenid mussels are impacting the nearshore, as seen in the eastern basin of Lake Erie. As a result of the dreissenids, chlorophyll a (chla) concentrations are significantly lower in the nearshore of Lake Erie, but higher in the nearshore in the three African Great Lakes, as well as pre-dreissenid Lake Erie. The objective of my thesis was to determine the limiting nutrient(s) to the phytoplankton of the Great Lakes Erie, Malawi, Tanganyika, and Victoria in both the nearshore and offshore by measuring the physiological status of the phytoplankton. I also examined how dreissenids affect the distribution of seston and nutrient concentrations between the nearshore and offshore of the eastern basin of Lake Erie. My study design included temporal and spatial surveys in the nearshore and offshore of the four lakes, in which I used a variety of nutrient limitation indicators for P (C:P, N:P, P debt, APA, Fv/Fm), N (C:N, NH4 debt, NO3 debt, Fv/Fm), and Fe (Fv/Fm), as well as photosynthetic efficiency (Fv/Fm) experiments. Nutrient enrichment experiments were also conducted in the nearshore and offshore of the eastern basin of Lake Erie which involved the addition and removal of Fe alone, as well as in combination with P and/or N. Lake Erie nutrient enrichment experiments provided evidence for P, N and Fe colimitation where the addition of Fe with P relieved Fe and P limitation and allowed nitrate (NO3-) assimilation, alleviating N limitation. However, the offshore experiments indicated stronger Fe limitation than the nearshore experiment. Lower chla concentrations in the post-dreissenid nearshore of the eastern basin of Lake Erie may not be due entirely to lower phytoplankton biomass, as photoacclimation of the phytoplankton may also be occurring. Dreissenid grazing effects can be seen in the distribution of dissolved nutrient concentrations between the nearshore and offshore of post-dreissenid Erie. The African Great Lakes are threatened by expanding human populations, resulting in increased nutrient runoff; the consequences of which will depend on the limiting nutrient(s). I found that the nearshore regions of Lakes Malawi and Tanganyika were colimited by N and P, while the offshore regions were colimited by N, P and Fe. The nearshore of Lake Victoria was colimited by light and N, while the offshore was colimited by N, P and Fe. Fe limitation only occurs in the offshore, and positive, significant relationships were found between total dissolved Fe concentrations and cyanobacteria. Continued P and Fe loading to the lakes will create a higher N demand that will result in a shift to N2-fixing cyanobacteria, which has serious consequences to human and ecosystem health as they are a poor nutritive food source and some are potentially toxigenic. The majority of studies conducted on Great Lakes involve offshore sampling, however, the less understood nearshore is where human impacts and activities are concentrated. I discovered there are significant differences between the nearshore and offshore, which has implications for water quality monitoring.

Cette étude utilise une approche multidisciplinaire à dominante géochimique, avec plusieurs objectifs : 1) mieux comprendre les processus géochimiques au cours du cycle de genèse des formations sédimentaires (érosion-transport-accumulation) pour des stages précoces de l'évolution d'un bassin de rift : 2) reconstruire les environnements caractérisant ces deux régions du Rift Est-africain au cours du Pélistocène et de l'Holocène et 3) définir des critères sédimentologiques et géochimiques permettant de discriminer l'activité tectonique et les changements climatiques au cours de l'évolution de ces deux bassins du rift. Les deux bassins considérés comme illustrant deux stages précoces successifs de l'ouverture d'un bassin de rift, sont : 1) le Bassin de Makgadikgadi-Okavango-Zambeze (MOZ), situé dans la région nord-ouest du Botswana et 2) le Bassin de Mpulungu, qui constitue l'extrémité sud-est du Bassin du Lac Tanganyika (Tanzanie et Zambie). L'étude géochimique des sédiments et des eaux du Bassin de l'Okavango a révélé la présence anormale d'arsenic dans les eaux souterraines du delta résultant de la dissolution sous conditions réductrices dans les sédiments. La présence de l'arsenic dans les sédiments est liée aux argiles riches en matière organique déposés dans les conditions lacustres résultant de périodes à pluviométrie plus importante qu'aujourd'hui et du barrage des écoulements de la rivière de l'Okavango apr la faille de Thamalakane. Les données géochimiques ont été utilisées comme marqueur deschangements du climat dans le bassin de Mpulungu. Les sédiments révèlent une excursion remarquable qui coïncide avec le Younger Dryas. Cet événement environnemental apparaît comme le plus important dans la région sud du lac Tanganyika pour la période 23-3 ka, caractérisée par un apport de matériel altéré dans le bassin, suite à une modification importante du couvert végétal.

No description available.

Amidst the confrontation between the East and the West Bloc during the Cold War, the decolonization of Africa created an entirely new ideological battlefield for these two sides to compete with one another for power and influence. The Federal Republic of Germany, having been allowed to rearm its military less than a decade prior, sought to gain influence in Nigeria and Tanzania by providing them with military aid. However, in both cases it failed to fulfill its promises of aid. Through the examination of these case studies, this study argues that the Federal Republic’s ability to provide effective military aid to non-NATO countries was limited due to the combination of its cautious foreign policy and the dynamic political landscape of the countries to which it offered aid. Formerly classified government documents and newspaper articles constitute the majority of this study’s source material. While current historiography focuses on the impact of the Cold War superpowers in regions outside of Europe, less attention has been given to the important roles that smaller powers such as the Federal Republic have played. By analyzing a smaller global player, the goal of this study is to complicate the notion of the Cold War being binary in nature. Furthermore, it aims to illustrate the political tightrope that the Federal Republic walked when conducting military aid which stemmed from the legacy of its violent past and its status as a divided nation.

No description available.

Lake Tanganyika is a complex, tropical ecosystem in East Africa, harboring an estimated 2,100 species. Extensive watershed deforestation threatens the biodiversity and ecological integrity of the lake. In this dissertation, ecological and paleoecological methods were employed to study the distribution of invertebrate biodiversity through space and time, with particular emphasis on linkages between biodiversity and land –use patterns. Ecological surveys of fish, mollusc, and ostracod crustacean diversity at sites in northern Lake Tanganyika representing different levels of watershed disturbance revealed a negative correlation between biodiversity and intensity of watershed disturbance. To elucidate the long -term relationship between disturbance and biodiversity, paleoecological records of invertebrates offshore from watersheds experiencing different degrees of anthropogenic disturbance were examined. Life, death, and fossil assemblages of ostracod valves were compared to assess the reliability and natural variability inherent to the paleoecological record. These comparisons indicated that paleoecological (i.e. death and fossil) assemblages reliably preserve information on species richness, abundance, and occurrence frequency at comparable -to- annual resolution. Unlike life assemblages, species composition of paleoecological assemblages reflects input of species from multiple habitat types. Ostracod paleoecological assemblages are characterized by spatiotemporal averaging that renders them representative of larger areas and longer time spans than life assemblages. Thus, paleoecological assemblages provide an efficient means of characterizing longer -term, site -average conditions. Natural variability in ostracod fossil assemblages from a sediment core representing the Late Glacial to the present indicates that abundance of individual ostracod species is highly variable. Ostracod assemblages were preserved in only the most recent 2,500 years of sediment. Species composition of ostracod assemblages reflects lake water depth. Core geochemical data indicate that the coring site may have been below the oxycline for ~2,000 years, inhibiting ostracod survival and preservation. Paleoecological, sedimentological, and stable isotope data revealed differences in biodiversity and watershed disturbance through time offshore from a pair of sites. The protected site is offshore from Gombe Stream National Park (Tanzania), the other offshore from a deforested watershed outside the park. Offshore from the deforested watershed, sedimentation rates increased, and turnover in ostracod species composition occurred during the past 50 years. Comparable changes were not observed offshore from the park.