M.Comm.

PhD. (Environmental Management) / This research investigates associations between El Niño Southern Oscillation (ENSO) phases and the occurrence of an unusual atmospheric transport patterns over southern Africa, observed during the SAFARI 2000 field campaign. This transport pattern manifested itself as a smoke and hazeladen flow, originating from the sub-equatorial tropical regions over northern Angola and western Zambia, and traversing the subcontinent with exit off the south-east coast over southern Mozambique and northern KwaZulu-Natal into the Indian Ocean. This pattern has been dubbed The River of Smoke. This pattern is distinctly different from the continental re-circulation pattern associated with continental high-pressure systems over the subtropical sub-region, which is the prevalent system according to current literature. The period during which the SAFARI 2000 campaign was conducted happened to be at the height of the strong 1999/2000 La Niña episode, associated with excessively wet conditions over the sub-continent. In contrast, during an earlier field campaign, SAFARI’92, the continental re-circulation transport mode, termed the gyre, was observed to prevail over the subtropical sub-region. SAFARI’92 coincided with the 1991/1992 El Niño episode that resulted in drought conditions over much of southern Africa. These observations triggered the current investigation of the causal associations and frequencies of the River of Smoke flow with phases of the ENSO. This study has employed conventional and modeled methods of meteorological analysis to investigate the influence of ENSO on atmospheric transport and synoptic coupling mechanisms, Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) forward trajectory computations supported by an enhanced method of cluster analysis were used to determine and characterize the mean atmospheric transport modes over the subcontinent. Trajectories were calculated originating at two source points, representative of the tropical and subtropical subregions respectively (Mongu, Zambia; and Tshane, Botswana). Three study years were selected, corresponding to three distinct phases of ENSO: an El Niño episode during 1991/1992, a neutral ENSO episode during 1996/1997, and a La Niña episode during 1999/2000. The National Center for Environmental Prediction (NCEP)/ National Center for Atmospheric Research (NCAR) Reanalysis model is employed to reproduce mean composite synoptic circulation fields over southern Africa during the three periods. Findings show that for airflows originating over tropical southern Africa, the Indian Ocean fast exit pathway is unique to the neutral ENSO phase, while the continental re-circulation transport mode exhibits zero occurrences during the neutral phase. A continental re-circulation transport mode in the lower troposphere was observed during the El Niño and La Niña extremes, but with low annual frequencies (less than 30%). The direct Atlantic Ocean, the north-west and the Indian Ocean slow exit pathways are common to all three ENSO phases. For airflows originating over the subtropical sub-region, the continental re-circulation transport mode has the highest vi frequencies during all three ENSO phases, more especially during the El Niño episode, with more than 50% annual frequency, as observed during SAFARI’92. The north-west, Indian Ocean slow and Indian Ocean fast pathways are observed during all the three ENSO phases, with lower overall frequencies. The anticyclonic circulation flows are driven by the strengthened high-pressure systems over southern Africa: the semi-permanent subtropical high-pressure systems over the adjacent oceans (Atlantic Ocean High and Indian Ocean High) and the transient cut-off continental high-pressure systems. Airflows exiting toward the Indian Ocean have been described previously. In this work, a novel distinction is made between the Indian Ocean fast and the Indian Ocean slow exit pathways. The Indian Ocean slow corresponds to the conventional off-coast flow, such as observed during SAFARI’92. The Indian Ocean fast exit pathway is a newly described transport mode, which results from strong coupling between the subtropical circulation systems and the mid-latitude westerly flows. This strong-coupling induced transport mechanism provides favourable conditions for transport of mass fluxes, such as fire emissions originating from the tropical sub-region, towards the Indian Ocean. The Indian Ocean fast exit transport mode is characterized by higher speeds while exiting off the south-east coast, and extends further into the temperate latitudes towards Australia. When coupled with tropical sub-region, this flow mode is responsible for the occurrence of the River of Smoke phenomenon identified during SAFARI 2000. This Indian Ocean fast transport mode is intermittent in nature, and couples to the tropical sub-region only during the neutral ENSO episode, during which it exhibits low monthly frequencies, mainly during the dry season July through October. The intermittent nature, dependent on ENSO phases, and the associated low frequencies, may explain why it was observed in SAFARI 2000, but escaped observation and comment during previous studies, such as SAFARI’92.

Magister Commercii - MCom / The aim of this study was to determine which strategy would be most appropriate to enhance regional trade integration in COMESA so that it can provide to its member states the benefits they expect to have from it. / South Africa

Magister Artium - MA / The researcher has been working for CIAT, as a community development facilitator and research assistant for past five years (2001-2006). CIAT has been involved in testing tools and methods for promoting participation and tracking changes at community level under different pilot projects in Eastern and Central Africa in partnership with national research organizations of respective countries. One of CIAT’s areas of research is developing participatory monitoring and evaluation systems that are appropriate for rural communities. The researcher has been involved in designing and setting up community-driven participatory monitoring and evaluation systems on a pilot basis with communities in Eastern and Southern Africa. / South Africa

Magister Philosophiae - MPhil / The problem that will be investigated in this research project may be formulated in the following way: Which tendencies may be identified in the mission programmes of the Methodist Church of Southern Africa during the period from 1980 to 2000? This thesis will provide a critical historical overview of missionary tendencies in the Methodist Church of Southern Africa from 1980 to 2000 with particular emphasis on the Journey to a New Land Convocation held in 1995. From 2000, the Methodist Church of Southern Africa had begun to reconsider the changes implemented following the Journey to a New Land Convocation. It will investigate such tendencies in the light of the emerging ecumenical paradigm of Christian mission as postulated by David Bosch. I will argue that three phases may be identified in the focus of the mission of the Methodist Church of Southern Africa during this period, namely 1) a period of ecumenical involvement from 1980-1993, 2) the introduction of the process called a “Journey to a New Land” from 1993 to 1995 and 3) the impact of this process on the mission of the Methodist Church of Southern Africa from 1995 to 2000. The thesis will provide an overview and critical analysis of these phases in order to assess whether the emerging ecumenical paradigm of Christian mission as postulated by David Bosch is reflected in each of these phases. A literary review indicates that the missionary focus of the Methodist Church of Southern Africa does not reflect the emerging postmodern paradigm of working towards togetherness. Nor does it proclaim a vision of unity but shows a tendency towards denominational needs. It does not embrace a diversity thereby enriching its missionary focus to give substance to the emerging ecumenical paradigm but shows more divergence than integration. There is also clear evidence that it opted for a holistic rather than a pluralistic approach to defining its missionary focus.

Philosophiae Doctor - PhD / Frankia is one of two partners in the globally distributed N2-fixing actinorhizal symbiosis between this filamentous soil-dwelling actinomycete and almost 300 species of host plants from eight diverse angiosperm families. The actinorhizal symbiosis is a major contributor to nitrogen reservoirs in terrestrial ecosystems, and allows actinorhizal plants to perform the role of pioneers in newly formed and nitrogen-poor soils. Frankia are differentiated into four main host-infection groups (1: Alnus/Comptonia/Myrica-infective, 2: Rosaceae/Datisca/Coriaria-infective, 3: Elaeagnaceae/Gymnostoma-infective and 4: Casuarina-infective), and there is a large degree of phylogenetic clustering within these HIGs. Of these host lineages, species from the genus Morella, from the family Myricaceae, are notable as they have the ability to establish effective partnerships with Frankia from more than one host-infection group. Africa houses 16 of the world’s 33 currently accepted Morella species, and Morella is the continents only genus containing endemic actinorhizal species. Despite this, the diversity of Frankia in symbiosis with African Morella has never been explored. To address this lack of knowledge I investigated Frankia in root nodules of six Morella species from the Cape flora of Southern Africa, as well as in rhizosphere soils from selected hosts. Partial nif H gene fragments recovered from 202 root nodules yielded 26 unique sequences, which phylogenetic analysis assigned to Frankia Cluster I (the Alnus host infection group) and Frankia Cluster III (the Elaeagnus host infection group)1. Nineteen nif H sequences were assigned to three sub-clusters within Frankia Cluster III (CC-3, CC-4 and CC-5), and the remaining seven sequences to two sub-clusters within Cluster I (CC-1 and CC-2), one of which (CC-1) is novel to the current study. Identical sequences were recovered from nodules collected at geographically distant locations, suggesting a cosmopolitan distribution within the region for some subgroups from both clusters, but more localized distribution (or tighter host-specificity) for others. Soil pH correlated with strain presence in nodules, with Cluster I sequences being associated with hosts growing in acidic soils exclusively. Furthermore, three Morella species from the Cape flora of southern Africa are promiscuous in their natural habitats, with host infection group influenced by habitat edaphic conditions. In order to explore the correlation between soil characteristics and Frankia presence in nodules, nif H soil libraries were created from selected host rhizospheres. While Cluster III sequences from these libraries corresponded closely to sequences found in nodules from the same sites, the dominant Cape Cluster I group (CC-1) was absent from all six libraries, even when present in nodules recovered from the same soils. Whether this was due to low abundance of -but strong selection for- these strains by hosts under particular conditions, or due to the absence in soil of hyphal forms of these strains could not be determined. Cluster III strains are known to be better able to persist saprophytically than their relatives from other host-infection groups. A second group of Cluster I strains, detected at only one sampling site, was present in that site's corresponding soil library. An Alnus-infective subgroup, cluster AI, which has been detected in soils collected on five continents, was also detected in the of the Cape soil libraries but never in nodules, raising questions as to this group’s ability to persist in soil in the absence of known suitable hosts. Ten Frankia strains representing all three of the numerically dominant subgroups (CC-1, CC-3 and CC-4, found in 186 of 202 root nodules) were isolated from four Morella species. These isolates represent six of the most abundant unique nodular nif H sequences found in the field survey, and display morphological and cultural characteristics typical of Frankia. Phylogenetic analysis confirmed their identity as Frankia, and multilocus analysis revealed that the isolates belong to three genospecies. Two of these genospecies fall into existing groups within the Elaeagnus-infective Cluster III, while the remaining genospecies is a novel addition to the otherwise well-described Alnus-infective Cluster I. Whole genome sequencing of a representative from each of the Cape genospecies allowed for basic annotation and genome descriptions, which agreed in each case with what has been previously found for strains from the Elaeagnus and Alnus host-infection groups, respectively. Similarly, the organization of nitrogenase gene clusters in each of the sequenced strains mirrors that found in other strains from their respective host-infection groups, indicating that this gene cluster is highly conserved in different Frankia lineages. For the first time the diversity of Frankia nodulating endemic African Morella, and present in root-associated soils of these species, has been explored. This is also the first study to report isolation and description of Frankia strains from actinorhizal plants endemic to Africa.

Open file dissertation.pdf to read abstract / Dissertation (MSc)--University of Pretoria, 2007. / Geography, Geoinformatics and Meteorology / Unrestricted

The present thesis concerns the population history, evolutionary processes and phylogenetic relationships of lineages of the redfin minnow genus Pseudobarbus. First, the population history and evolutionary processes within P. quathlambae were determined, mainly to decide the conservation value of the Mohale population. The Mohale dam threatens its survival. A divergence in mitochondrial control region and cytochrome b sequences and frequency differences in the distribution of major histocompatibility alleles were found between the Mohale population and an “Eastern” lineage. The Mohale population has therefore been historically isolated and was deemed indispensable for the conservation of P. quathlambae. Differentiation among populations of the P. afer and P. phlegethon complex were investigated, in relation to geological and climatic processes. Sea levels were about – 130 m below present levels during the last glacial maximum, about 18 000 years ago. Five historically isolated lineages were identified through analysis of mitochondrial control region sequences. The four P. afer lineages showed a strong association with proposed palaeoriver systems. A “Forest” lineage, however, reaches across two proposed palaeoriver systems. Surprisingly, this lineage is closely related to P. phlegethon. Pseudobarbus asper and P. tenuis were analysed together, because of their close phylogenetic relationship and because they occur in sympatry in the Gourits River system. Pseudobarbus tenuis showed divergence in mitochondrial control region only between the Keurbooms and Bitou River systems compared to the Gourits River system. Within P. asper, divergence was low, suggesting recent inland exchange opportunities between populations of the Gourits and Gamtoos River systems. River capture of south-eastern tributaries of the Gourits River system by the Keurbooms River would have resulted in unidirectional colonization, suggesting that speciation between P. asper and P. tenuis occurred within the Gourits River system with or without the Gamtoos River system being involved. Lower sea levels during the last glacial maximum also played an important role in the population history of P. burchelli. Differentiation in P. burchelli did not occur between two proposed palaeoriver systems, but rather within a western palaeoriver system. Divergence in mitochondrial control region and cytochrome b sequences showed that the “Breede” and “Tradou” lineages diverged within the Breede River system, before the “Heuningnes” lineage became isolated in the Heuningnes River system. Fifteen historically isolated Pseudobarbus lineages were included in a phylogenetic analysis on which biogeographic hypotheses were based. Phylogenetic relationships based on mitochondrial control region, cytochrome b and 16S and a combined dataset of all these were compared to relationships recovered from a previous morphological dataset. Conflicts between the molecular and morphological analyses, suggests that several morphological characters evolved in a complex manner. The molecular phylogenies suggest that the earliest divergence in the Pseudobarbus was between P. quathlambae in the Orange River system and the other species that occur in the Cape Foristic Region. Pseudobarbus lineages with two pairs of barbels and those with a single pair of barbels (excluding P. quathlambae) grouped together. In terms of currently described species, only the two lineages of P. quathlambae and the three lineages of P. burchelli were clearly monophyletic. Copyright / Thesis (PhD (Genetics))--University of Pretoria, 2007. / Genetics / unrestricted

Namibia’s community based natural resource management program (CBNRM) integrates local participation in rural development and biodiversity conservation. This effort was launched through key legislation that devolved the right to manage wildlife and other renewable resources on communal lands from the state to community level conservancies. Local participation is dependent upon the capacity of the locals to self mobilize and establish conservancies, plan and implement their programs, and monitor and evaluate their progresses and impacts. Accordingly, this study examines the role of capacity development (CD) in CBNRM, particularly its processes, products, performance, and permanence at the individual, organizational (conservancy), and community levels. The research was carried out using interviews and participatory self-assessment exercises with various conservancy stakeholders. This study uncovers why and how capacity development has to be based on local realities and aspirations where capacity users need to have ownership of the process through partnerships with service providers in order to enhance endogenous capacity. However, such notion of “partnership” between CD stakeholders is challenging to translate into reality in the face of power imbalances, where government and NGOs are continuously influenced and coerced by donor interests, where NGOs are considered stronger than the government because they control more financial and human resources, and where conservancies tend to report upwards to NGOs and government instead of their constituents. Moreover, this research reiterates that CD has to be holistic enough to incorporate individual, organizational, and community level changes in order to create sustainable capacities and prevent problems of elitism, manipulation, and dependency on few individuals. With respect to CBNRM, the research argues that its basic premise of diversifying rural livelihoods using incentives to bring about sustainable resource management can only be achieved when conservancies have the capacity to create representative and participatory democratic processes, and when they are able to generate equitable and reliable tangible benefits with manageable costs to their constituents. As seen in this study, when such governance and benefit sharing structures are in place, they enhance local participation by promoting political empowerment, trust, ownership, and positive attitude towards living with wildlife. However, if such conditions are not met, local participation is reduced, while intra-community conflicts from marginalization to nepotism and members’ dissatisfaction and disinterest are inevitable. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

The bluetongue (BT) live attenuated virus vaccine has been used successfully in the control of BT in southern Africa and Europe. However, concerns about the safety, possible development of viraemia and clinical signs post vaccination (p.v.) presented an opportunity to investigate the possibility of reducing the current bluetongue virus (BTV) vaccine titre to below 104PFU/ml. A total of 83 merino sheep were used and vaccinated with BTV monovalent vaccines containing either serotypes 2, 4 or 8 with the following titres: 102, 103 and 104 PFU/ml. Positive and negative control sheep were also included. Animals were bled from Day 0, 3, 6, 9, 12, 15, 18, 21, 25 and 28 p.v and tested for viraemia. Seroconversion was determined on Day 0, 3, 9, 15, 21, 6 weeks, 3 and 4 months p.v. Vaccinated sheep were then challenged at 6 weeks p.v. using BTV infected blood and at 4 months using cell cultured material and evaluated for 14 days using the clinical reaction index. Seroconversion was demonstrated p.v. in more than 70% of sheep vaccinated with a low titre 102 PFU/ml of BTV serotypes 2, 4 and 8 from day 9 and at 4 months. All three serotypes did not demonstrate any viraemia p.v. at the three different titres (102, 103&104PFU/ml). Viraemia was demonstrated p.c. with cell culture material in sheep vaccinated with low titres (102&103 PFU/ml) of BTV serotypes 2 and 4. Viraemia could not be detected in sheep p.v. and p.c. with BTV serotype 8 in all different titres. Sheep challenged with cell culture material of BTV 2 and 4 showed mild clinical signs compare to those challenged with blood culture material that did not respond as expected as positive controls did not demonstrate any clinical signs of BT. It was demonstrated in this study that BTV monovalent vaccines containing serotypes 2, 4 and 8 with titres below 104 PFU/ml can protect more than 90% of vaccinated animals against clinical disease. Although certain serotypes failed to protect against viraemia, all serotypes protected against the development of clinical disease when challenged with either BTV-infected blood or cell cultured material. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Veterinary Tropical Diseases / unrestricted