Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"tropical Africa"”.
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Satellite derived rainfall over tropical Africa : its pattern variability and calibration
… at seasonal and intra-seasonal time-scales over tropical Africa are identified by principal component analysis. Pentad CMAP rainfall and NCEP 700hPa zonal wind for the period 1980-2000 were used. Wavelet analysis is used to filter the data sets for cycles between 20-70 days for the intra-seasonal …
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Evolution of the African Tigerfish (Genus Hydrocynus) : phylogeographic insights into drainage evolution
… genus, Hydrocynus, which is widespread across tropical Africa, is reconstructed using a phylogenetic framework and divergences are dated using the cytochrome b (cyt) region.
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Biogeography of Isolepis subgenus Fluitantes (C.B. Clarke), Muasya (Cyperaceae): niche conservatism, long distance dispersal and hybridization
Numerous lineages of the Western Cape of South Africa show affinities with the flora of tropical Africa and with Australasia. Recent work suggests that most migrations between the Western Cape and tropical Africa occur in a northward direction, and that connections between the flora of regions in …
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Phytochemical Investigation and Drug Interaction Potential of <em>Cyanotis vaga</em>
… perennial herb. It is native to Eastern Asia and Tropical Africa. It has been reported that its decoction reduces fever and enhances well-being. Recently, <em>C. vaga</em> has been used widely for its anabolic effects, due to its richness of ecdysteroids. Even though <em>C. vaga</em> is a …
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Co-Existence of Urinary Tract Infection and Malaria Among children Under Five Years: A Case of Muhimbili National Hospital Dar es Salaam,Tanzania.
Across tropical Africa, febrile children are treated for malaria either with or without confirmation thus resulting in failure to diagnose and treat other co-morbidities like urinary tract infections (UTI) and upper respiratory tract infection (URTI) that may coexist with malaria. This …
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The biogeography, phylogeny, and dispersal of freshwater and terrestrial free-living ciliates in Florida, USA.
… and terrestrial ciliate populations of sub-tropical Florida, USA, an uninvestigated geographic range with similar environmental characteristics to those found in previously- studied locations in sub-tropical and tropical Africa. Through extensive sample collection covering a wide variety of …
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Mechanisms of inter-annual rainfall variability over tropical highlands of Africa and its predictability potential
Modes of climate variability over tropical Africa and adjacent Atlantic and Indian Oceans are investigated using continental monthly averages of gridded rainfall and temperature and marine environmental data, which consists of monthly averages of sea surface temperature, sea level pressure and …
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On the phylogeny and diversity of the microsoroid ferns (Polypodiaceae)
… 180 species (PPG I, 2016) and found mainly in tropical and subtropical Asia, Australasia, the Pacific Islands, Madagascar, and tropical Africa. The relationships between groups of this subfamily have long been controversial, especially the delimitation of the genus Microsorum, which, based on …
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Impacts of Congo Convection on Tropical Africa's circulation, rainfall and resources
The impact of central African convection on surrounding circulation is examined. The convection over the Congo basin is estimated using satellite OLR (Outgoing Long Wave Radiation) as an index. It is then related to the regional and global circulation. OLR indices for the Congo area 15°-30°E, …
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Using real-time forest loss alerts and global deforestation maps to assess the effectiveness of Africa's tropical protected areas
Tropical rainforests harbor a significant portion of the world's remaining biodiversity. Having undergone rapid changes in forest cover over the last two decades, a large amount of irreplaceable biodiversity has been lost. The establishment of protected areas has been a key strategy to hinder the …
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The rhino horn and ivory trade: 1980-2020
In much of tropical Africa a breakdown in law and order, corruption and an influx of firearms led to heavy rhino and elephant poaching, especially in the 1970s and 1980s. I collected and analysed data to reveal the collapsing numbers of rhinos in Africa. Although we had general trade information, …
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Paleoclimate and paleoecology of Miocene Eastern African primate habitats : a multiproxy approach.
… Miocene climate and ecosystem in eastern Africa is essential for understanding the environmental and geological contexts in which early primates evolved. Particularly, correlations between leaf size, shape, temperature, and precipitation have become a widely used tool for paleoclimate and …
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Utilization of water and light resources by annual crops under semi-arid conditions when planted between Leucaena leucocephala (Lam.) de Wit hedgerows
… very successful in, many rural communities in tropical Africa and Asia. Adoption in semi-arid Africa has been less widespread, and often less successful once implemented. Nevertheless, the risk reduction possibilities that agroforestry offers through crop complementarity and yield …
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Lacustrine Turbidites from Tropical African Lakes as Indicators of Hydrologic and Climatic Changes
… changes, yet their usefulness as recorders of tropical paleoclimate variability has long been overlooked. The primary focus of this dissertation research is to investigate the late Quaternary hydroclimatic changes in tropical Africa, using hyperpycnites, dated sediment cores, and …
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Topographic evolution of the East African Plateau : a combined study on lava-flow modeling and paleo-topography
The East African Plateau provides a spectacular example of geodynamic plateau uplift, active continental rifting, and associated climatic forcing. It is an integral part of the East African Rift System and has an average elevation of approximately 1,000 m. Its location coincides with a negative …
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Tree-ring analysis and stem biomass estimation of limba (Terminalia superba Engl. & Diels) in the framework of sustainable forest management
… of quantitative data, often not available in tropical forests. The lack of long-term data on tree growth, wood production and carbon stocks hampers the implementation of sustainable forest management and possible financing by Kyoto Protocol related tools like REDD+ and Clean Development …
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Diet Assessment in Tropical African Populations - the implications of detecting biological signals in current diets to the study of past diets
East Africa is central to many aspects of human evolution and diversification. At the same time, diet is a key aspect of the ecology of any population. Therefore, one is often interested in the diets of past populations. To assess human diet in the past, stable isotope ratio and dental microwear …
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Understanding Patterns of Phenotypic Variation in a Contemporary Population and Ancient Lineage of Fishes
… fishes that occur in freshwater habitats in tropical Africa and the Nile River system, typically in shallow swamps, floodplains and estuaries. Overall, understanding patterns of phenotypic diversity both within a species or within a lineage across time are important goals in evolutionary …
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Molecular phylogenetics, taxonomy and niche-based conservation risk assessment of Thesium L. (Santalaceae)
… and a greatest concentration in southern Africa (ca. 186 species). Although Thesium is a major component of southern African flora, it often goes unnoticed and is poorly studied. The last revision of the entire genus was done by De Candolle in 1857. South African Thesium was last revised …
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Deciphering multiple changes in complex climate time series using Bayesian inference
… records interpreted as climate indicators of the African region of the Plio-Pleistocene period. A detailed inference unravels multiple transitions underlying the indirect climate observations, that are interpreted as conjoint changes. The identified conjoint changes coincide with established …