Dissertations / Theses on the topic 'Elsenia'

The McTronX research group has conducted extensive research concerning Active Magnetic Bearings (AMBs). This research involved the establishment of an advanced AMB laboratory to aid in assisting industries that implement AMBs in their applications. This year the McTronX group’s focus shifted toward the development of an AMB system to be implemented in the Pebble Bed Modular Reactor (PBMR). The AMB system was designed to be used in a helium blower application. This involved the development of both the mechanical and the electronic components. The main goal of this AMB system was to develop a completely digital integrated controller which is responsible for the control of the AMB system, from here on referred to as the AMB drive and electronic system (ADES). The need arose for a totally digital system to increase the reliability and robustness of the ADES. These requirements are crucial in a nuclear environment. In order to develop a totally digital system a new issue had to be addressed. This involved the implementation of digital communication. This project involved the development of a communication sub‐system for the ADES. The communication system was divided into two sections, the internal and external communication system. The various interfaces were identified as well as their specifications formulated. The optimum solution was then selected for each of the interfaces by using a design process that involved comprehensive trade‐off studies. The external communication system and the internal communication system were specified and the necessary hardware was procured. An in‐house developed protocol was developed and implemented between the internal functional units of the ADES. The designed protocol adhered to the specific needs of an AMB application. The protocol was extensively tested by carrying out verification and validation tests and evaluation plans. The test and evaluation plans for verification were carried out by making use of simulations and laboratory experiments. Validation of the in‐house developed protocol was carried out by analyzing the internal communication system whilst the ADES was controlling the bearing module. During this phase the communication system was also subjected to error conditions. The protocol proved to be completely functional, robust and reliable, meeting the performance specifications and the requirements. During this project a foundation was laid for digital communication in AMB systems in the McTronX research group.
Thesis (M.Ing. (Electronical Engineering))--North-West University, Potchefstroom Campus, 2010.

Australia supports a highly endemic freshwater fauna. The continent's long isolation, Gondwanan heritage, and present aridity make it of particular interest to freshwater biogeographers. Recent molecular genetic studies of freshwater fishes and macroinvertebrates implicate diverse processes of landform evolution, climatic change and sea level fluctuation in shaping current patterns of biodiversity. These studies indicate a biogeographic complexity for Australian freshwaters that is not yet well understood, especially throughout the geographically complex eastern coastal margin. Australian freshwater turtles are one of the continent's few vertebrate freshwater Gondwanan relics that are still taxonomically and ecologically diverse, and geographically widespread. However, in context of their biogeography they remain poorly studied, despite studies on other continents showing turtles to be particularly suited to illuminating complex evolutionary processes. In this thesis is explored the sensitivity of freshwater turtles as models for biogeographic inference in an Australian context, to seek new insights that may clarify and extend our knowledge of Australian freshwater biogeography. Molecular genetic tools are developed and applied to investigate phylogeographies of turtle species from two Australian genera. The evolutionary history of riverine specialist Australian snapping turtles (genus Elseya) is compared to that of the more ecologically generalist and widespread subspecies of Emydura macquarii, and in particular that of Krefft's river turtle, E. m. krefftii. These taxa were chosen as models because both are primarily riverine and broadly sympatric throughout eastern Australia, but differ significantly in niche breadth, range size, and expected dispersal ability. To address the lack of suitable genetic resources available for Australian short-necked turtles, Next-Generation shotgun genome sequencing was evaluated as a cost-effective means of developing novel genetic resources in two species of freshwater turtle. Low-coverage Roche 454-sequencing was used to randomly sample genomic sequence data for microsatellite repeats in the study species Elseya albagula and Emydura macquarii krefftii. Thousands of microsatellite loci suitable for amplification by PCR were found. Of these, 29 loci were developed for high-resolution population genetic analyses in the study species, which also cross-amplified successfully in a range of other Australian short-necked turtle taxa. Further bioinformatic exploration of the genomic sequence datasets enabled reconstruction of nearcomplete mitochondrial genomes, and characterisation of gene content and repetitive elements. A molecular toolkit of nuclear and mitochondrial markers is presented that provides the foundation for research presented in this thesis, and which will also facilitate future genetic research on Australian freshwater turtles generally. Drainages within Australia's mid-eastern coastal region (Fitzroy, Burnett and Mary catchments) face considerable urban pressure and contain high freshwater biodiversity and endemism. Mitochondrial (~1.3 kb control region and ND4) and nuclear microsatellite datasets (12 polymorphic loci) were used to investigate genetic structure in the locally endemic whitethroated snapping turtle, Elseya albagula, to clarify historical biogeography and address pressing conservation issues for this species and this region. Individual drainage basins contained discrete genetic units (average pairwise FST = 0.15 and ФST = 0.75 among drainages), though the degree of divergence among drainages varied. The Fitzroy drainage contained a distinct evolutionary lineage, divergent from a second lineage occurring in both the Burnett and Mary drainages. Genetic data were used to make recommendations regarding recognition of evolutionarily significant units and management units for E. albagula. Geological evidence and genetic data for co-distributed freshwater species were consolidated to propose a shared biogeographic history for a diverse regional biota, reflecting historical isolation of the Fitzroy and recent coalescence of the Burnett-Mary drainages during lowered Pleistocene sea levels. To examine broader-scale evolutionary hypotheses associated with changes to regional riverine connectivity through eustatic sea level change, landform evolution and aridity, a multi-locus molecular approach incorporating mitochondrial (control region, ND4 and 16S) and nuclear (R35 intron) sequences was used to reconstruct phylogenetic relationships and estimate divergence times for all extant Elseya species (including undescribed forms) across Australia and New Guinea. The genus Elseya was shown to contain four divergent, geographically correlated clades, corresponding to all of New Guinea, southern New Guinea plus northern Australia, north-eastern Australia, and south-eastern Australia. These are estimated to have arisen in the Late-Miocene (between ~5.82-9.7 Ma), and diversified further in the early Pleistocene (between ~2.2-2.43 Ma and 1.36-1.66 Ma), coincident with major phases of aridity and climatic upheaval. Overall, snapping turtles were found to have a long vicariant history in Australia and New Guinea, tied to the disconnection of fluvial habitat through landform evolution, sea level change and ongoing aridification. Major implications of these genetic results for understanding freshwater biodiversity evolution in Australia are discussed, including evidence for periodic connectivity with New Guinea, important regional biogeographic barriers (Lake Carpentaria and the Burdekin-Fitzroy drainage divide), and the location of potential freshwater refugia. Krefft's river turtle, Emydura macquarii krefftii, are common throughout eastern coastal Australia and their extensive longitudinal distribution spans landscape and climatic barriers recently proposed as important in structuring regional freshwater biodiversity. Their evolutionary history in response to climatic oscillations and putative biogeographic barriers was examined using range-wide sampling (649 individuals representing 18 locations across 11 drainages) and analysis of mitochondrial sequences (~1.3 kb control region and ND4) and nuclear microsatellite (12 polymorphic loci) data. Competing demographic (local persistence versus range expansion) and biogeographic (arid corridor versus drainage divide) hypotheses were considered. Krefft's turtles exhibit significant genetic structure across their range at mitochondrial and microsatellite markers, consistent with isolation across drainage divides. Deep north-south regional divergence (2.2%, ND4 p-distance) was consistent with long-term isolation across the Burdekin-Fitzroy drainage divide, not the adjacent Burdekin Gap dry corridor. There was also evidence for rare contemporary overland dispersal across the Burdekin- Fitzroy watershed and for hybridisation with Emydura tanybaraga at the northern range limit. Data suggest Krefft's turtles persisted within the arid Burdekin region throughout multiple episodes of Plio-Pleistocene aridity, though very low contemporary genetic diversity indicates this may have been despite potential population bottlenecks. Overall, riverine turtle species examined in this thesis exhibited strong, geographically correlated, phylogeographic structure. A remarkable degree of genealogical concordance was observed in phylogeographical patterns between turtle taxa, and turtles and other freshwater groups. Though differences in range size and niche breadth were expected to produce disparities in dispersal ability and phylogeographic structure between the two turtle taxa, both exhibited a primary pattern of genetic structure reflecting isolation across drainage divides. Riverine turtles are indeed sensitive models for inferring historical processes influencing freshwater biodiversity in an Australian context. Molecular data presented in this thesis collectively demonstrate the importance of comparing phylogeographic patterns among co-distributed taxa with variable ecological tolerances and dispersal abilities. Furthermore, the current work not only highlights the potential value of further phylogeographic research into ecologically diverse freshwater turtles in Australia, but provides a comprehensive molecular toolkit for doing so.

Nationally and internationally the integration of people with disabilities into mainstream society is gaining attention. Leisure and sport play important roles in this integration process. Few services and opportunities, however, exist for people with disabilities to participate equally in society. It seems that recreation providers focus primarily on recreation programs for able-bodied people in communities. These inequalities are realized. It is also documented in the National Sport and Recreation Act (1998) that the development of sport and recreation opportunities for people with disabilities is important. Due to the numerous health benefits of leisure participation, lifelong participation needs to be encouraged when leisure opportunities are developed and implemented in communities. It is important that people with disabilities derive maximum benefit from sport and recreation involvement to ensure continued participation throughout the lifespan. Individuals derive maximum benefits from sport and recreation activity involvement when they perceive freedom during these activities. These activities range from athletics and soccer to chess and art. “Perceived freedom” is the central indicator of leisure functioning. Freedom can only be experienced when the learners with physical and learning disabilities experience satisfactory levels of leisure competence, control during leisure activities, needs satisfaction and depth of involvement as components of leisure functioning. The following hypothesis was formulated for the study: “Leisure functioning of learners with learning and physical disabilities does not contribute to an independent leisure lifestyle”. The aims of this study were to determine the following components of leisure functioning through the use of the standardised Leisure Diagnostic Battery (LDB):

• leisure competence of learners;
• being able to control the process and outcomes of leisure participation ;
• needs satisfaction and
• depth of involvement in leisure activities.

Data collected in this study were processed by means of quantitative research. Research methods included an external environmental analysis (literature reviews), an internal environmental analysis (internal policies and programs and interview), and a questionnaire. The questionnaire was administered to a sample of learners (38%) with physical and learning disabilities at an ELSEN (Education for Learners with Special Education Needs) School in Tshwane. It was found that learners at the ELSEN School had an 85% (63.73/75) leisure functioning rate. The learners with learning disabilities had a slightly higher leisure functioning rate of 85.32% (63.99/75) than the learners with physical disabilities with an 84.27% (63.2/75) rate. The high level of leisure functioning indicated that the learners perceived high levels of freedom during their leisure participation at the school. The formulated hypothesis could therefore not be accepted. The leisure functioning of the learners are high and should therefore contribute to an independent leisure lifestyle. In order to utilize the full potential of the leisure activities at the school the following aspects are suggested for further research:

• In order to increase leisure participation at the school, constraints hindering participation need to be determined.
• Assessment of a broader base of learners (including all the grades) would be recommended for further planning of programs and activities.

Dissertation (MA)--University of Pretoria, 2008.
Biokinetics, Sport and Leisure Sciences
unrestricted

Text in Afrikaans
The aim of this study was to identify and describe the components of a parent support program for the parent of children with mental retardation in the ELSENunits of Parow Preparatory School. This study is the first step in compiling a parent support program for full service schools, since it can be utilise in the establishment of such a program. This study does not address composition of such a parent support program. A qualitative approach was used. Empirical data was gathered through the use of focus groups consisting of 28 parents of children in the ELSEN-unit of Parow Preparatory school. An interview scedule consisting of semi-structured questions were used during the focus groups. Themes were identified and dealt with in accordance with relevant existing literature and literature control. Conclusions and recommendations were made in connection with the components of a parent support program for the parent of children in the ELSEN-units of Parow Preparatory School .
Social Work
M.Ed. (Kurrikulumstudies)