18105 research outputs found
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Making the personal political: understanding the impacts of participation in an anti-rape protest for women who have experienced sexual violence
Get PDFSouth Africa is recognised as a country with unusually high levels of rape and sexual violence. The majority of those who experience sexual violence do not acknowledge, disclose or report it, and do not access support. Many factors have been identified which can inhibit acknowledgement and disclosure. While silence is to be honoured as a chosen response, unwanted silencing is of concern. The annual Silent Protest at Rhodes University is a day-long anti-rape protest which draws attention to the attitudes and practices which silence victim-survivors, and enacts solidarity with victim-survivors of sexual violence. I conducted a three year “critically engaged, activist ethnography” with the community of Silent Protestors and organisers. My focus was on the stories that victim-survivors told about the impacts of participating in the protest. Changes in the research context allowed for a participatory action research cycle to be incorporated into the methodology. This offered an opportunity to implement and evaluate some changes suggested by my research contributors. My contributor’s narratives highlighted the ways in which as a society we position those who have been subjected to sexual violence in ways that are limited and limiting and which diminish victim-survivors’ sense of agency and value. This malignant positioning restricts the choices available to victim-survivors. The anticipation of being positioned in negative ways can inhibit victim-survivors from disclosing a violation and accessing care and justice. Participation in the Silent Protest seems to stand against some of the factors which inhibit acknowledgement and disclosure. Through their participation many women took up opportunities to share their story with at least one other person and to receive and offer care. Most described participation as having been beneficial and having helped them move towards living well again. The ways in which the Silent Protest positioned victim-survivors and the choices they were offered in relation to that positioning seemed to open up opportunities for thinking, feeling and acting in ways that they preferred. This suggests that interventions which mobilise both political resistance and mutual care hold promise for developing more accessible and effective services to those affected by sexual violence.Thesis (PhD) -- Faculty of Humanities, Psychology, 202
The development of ionic zinc(II) phthalocyanines for sono-photodynamic combination therapy of cervical and breast cancer
No full textThis study focuses on the development of the sono-photodynamic combination therapy (SPDT) activity of phthalocyanines (Pcs) on the cervical and breast cancer cell lines in vitro. The SPDT technique utilizes ultrasound in combination with light to elicit cytotoxic effects for cancer eradication. In this work, a selection of tetra-peripherally substituted Zn(II) cationic and zwitterionic Pcs were prepared. The photophysical parameters of the Pcs were determined including their fluorescence behaviours and efficiency of the triplet excited state population. The effects of the ultrasonic parameters (frequencies (MHz) and power (W.cm-2)) on the stability of the Pcs were evaluated. Four parameters were evaluated: Par I (1 MHz: 1 W.cm-2), Par II (1 MHz: 2 W.cm-2), Par III (3 MHz: 1 W.cm-2) and Par IV (3 MHz: 2 W.cm-2). The stability of the Pcs reduced with the increase in the ultrasonic power (for Par II and Par IV). The Par I showed the least degradation compared to the other parameters and was therefore used for the SPDT treatments. The sonodynamic (SDT), photodynamic (PDT) therapy activities of the Pcs were studied and compared to their SPDT efficacies. The Pcs showed reactive oxygen species generation during the SDT, PDT and SPDT treatments. For the SDT and SPDT, singlet oxygen (1O2) and hydroxyl radicals (•OH) were detected. For PDT, only the 1O2 were detected. The cell cytotoxicity studies for the Pcs showed relatively higher therapeutic efficacies for the SDT treatments compared to the PDT treatments, where the SPDT showed higher therapeutic efficacies compared to both the SDT and PDT monotreatments on both the cell lines in vitro. Overall, the combination treatments were better compared to the monotreatments. The activities of the Pcs were compared by their differences in structures, including the type of R-group, type of quaternizing agent and type of nanoparticle conjugates.Thesis (PhD) -- Faculty of Science, Chemistry, 202
Mineral paragenesis of olmiite/poldevaartite and rhodochrosite/shigaite occurrences in the Kalahari Manganese Field, and their relation to the formation of high-grade manganese ore of Nchwaning II mine, Black Rock, South Africa
Get PDFAccess restricted. Access embargoed until 2025.Thesis (MSc) -- Faculty of Science, Geology, 202
The influence of immuno-contraception on the ecology of African savanna elephants (Loxodonta africana) in a small game reserve in the Eastern Cape, South Africa
Get PDFAfrican savanna elephants (Loxodonta africana) can alter the vegetation structure on a landscape which has both positive and negative consequences for biodiversity. This ecological role can be dependent on the density of elephants in a given area and how the area is transformed. Elephants are currently listed as an endangered species on the International Union for Conservation of Nature (IUCN) global red list. Despite this endangered status, strong conservation efforts in southern Africa have increased elephant numbers in protected areas. In South Africa, many of these protected areas are small (<1000 km2) and fenced. Thus, without the freedom to roam over large areas, elephant impacts on vegetation and other ecosystem processes may be exacerbated. Increased growth rates and higher population densities, have prompted wildlife managers to explore several population-level management techniques to slow elephant growth rates in small, protected areas. One such technique is the use of immuno-contraception. My study focused on three datasets (Pre, During and Post porcine zona pellucida (PZP) treatments) of one elephant population over an 18-year period in a small game reserve in the Eastern Cape, South Africa. The first aim of my study was to compare the female demography and reproductive parameters of treated (with PZP) and non-treated females (no PZP). I predicted that the population growth would decrease as more elephant cows were contracepted as well as them having longer inter-calving intervals than non-treated cows. Further, I predicted that there would be a skewed sex ratio of male calves born to treated cows. Lastly, I predicted that fertility rates would be lower in treated cows than in non-treated cows. I calculated the annual population growth rates, inter-calving intervals, sex ratios, age at first calving, fecundity rates and fertility rates of all breeding cows. Population growth rates were similar to other managed populations although, compared to a relatively untouched elephant population, annual growth rates in my study site were high. The inter-calving intervals and age at first birth were low compared to other African protected areas which were most likely influenced by the use of PZP, rainfall and a lack of density dependence. Treated cows did not have longer inter-calving intervals compared to non-treated cows nor was there a male biased sex ratio of the offspring of treated cows. The second aim was to assess the spatial ecology of this elephant population and how it may be influenced by immuno-contraception. I predicted that the use of PZP would increase the elephant herd’s core range as there were fewer reproducing cows. I also predicted that PZP would alter the elephant’s habitat use making them less selective in terms of the vegetation types they selected. I compared the home ranges of the elephant population among the three treatments (Pre PZP, During PZP and Post PZP treatment). Home ranges were larger when elephants were treated with PZP compared to the Pre and Post treatments. The herd utilized most of the reserve during the use of PZP whereas prior to contraception, their space use was mostly concentrated on the eastern side of the reserve. Additionally, the vegetation utilization was inconsistent across the differing timeframes, specifically between pre PZP and during PZP. Prior to the use of PZP, the elephant herd utilized the old lands and riverine thicket the most whereas during the use of PZP, the grasslands and karroid habitats were used the most. The most likely influence of the changes in home ranges and vegetation utilization were rainfall, the use of PZP and resource availability. My results suggest that the use of PZP is essential for controlling elephant population numbers. However, there may be some long-term effects (e.g., behavioural changes) of the use of PZP in elephant populations in small game reserves. Thus, I recommend continued monitoring of all aspects of elephant ecology on reserves where PZP is used as a contraceptive technique.Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 202
Microbial and extracellular polymeric substance dynamics in arid–zone temporary pan ecosystems
Get PDFMicrobial communities of bacteria, viruses, algae, protozoans and fungi participate profoundly in aquatic systems, particularly in mediating processes such as primary production, decomposition, and biogeochemical cycles. In addition, microbiomes produce extracellular polymeric substances (EPS) which encompass a hydrated exopolymer mainly constituted of carbohydrates and proteins. The exopolymer aid proliferation and persistence of biofilms on their resident surfaces. There is however paucity of data on functional diversity of microbiomes in arid zone temporary wetlands with previous research having mainly focused on permanent systems in the northern hemisphere. In the face of ongoing climatic changes and anthropogenic threats to wetlands, it is imperative to assess the health status of aquatic systems in relation to microbial productivity dynamics. In this thesis, colorimetric methods and sequence–based metagenomics were conducted to quantify microbial EPS production and bacterial metagenome functions, respectively. This study was conducted in Khakhea–Bray region (North–West, South Africa) in June 2021 and January 2022 with a focus on evaluating microbial patterns of distribution between seasons (i.e., Dry and Wet) and varying depth i.e., deepest zones (Deep), intermediate depth (Mid) and shallowest regions (Edge). Additionally, potential relationships between EPS and either water content or organic matter content (OM content) were evaluated. In this study it was hypothesized that wet phases and deeper zones will have high EPS production and support more functions in comparison to shallowest regions and dry phases. Carbohydrates and proteins were quantified using the Dubois method and modified Lowry procedure, respectively. Carbohydrates generally occurred in higher proportions than proteins, suggesting that EPS found in these systems was largely diatom produced. The wet phases (wet season and inundation periods) supported more EPS production compared to the dry phases. The results of principal components analysis (PCA) and Spearman’s correlations suggested that EPS was highly correlated with sediment water content among other assessed variables. No significant associations were established between EPS and organic matter content. Spatial distribution of EPS demonstrated similar patterns between the deepest (Deep) and the intermediate depth zones (Mid) however the shallow regions (Edge) had significantly lower concentrations. Bacterial characterization was established by amplification of the 16S rRNA gene using illumina–sequencing protocol. Enzyme functions associated with biogeochemical pathways were predicted in PICRUSt2 bioinformatics pipeline. A total of 15 042 Unique Amplicon Sequence Variants (ASVs) were observed to be affiliated to 51 bacterial phyla and 1 127 genera. All top genera had commonality in heat tolerance. Firmicutes, dominated at phyla level with 59 % (mean ± sd, 19 ± 13 %) relative abundance followed by Actinobacteria and Proteobacteria both at 34 % (18 ± 7 %) and (18 ± 6 %), respectively. Microbial diversity matrices highlighted significant differences in beta diversity more than alpha diversity. Bacterial microbiomes were more distinct between seasons compared to within season, suggesting that functions were seasonally driven. These findings were supported by highest rates of denitrification, carbohydrate degradation and EPS production by core microbiomes in the wet season as compared to low rates of nitrogen mineralisation, carbon fixation and nitrification in the dry season. The present findings represent a first attempt in evaluating sequence–based metagenomics in semi–arid southern African temporary pan ecosystem. Both microbial EPS and bacterial functional potential were highly driven by water availability, with highest rates mainly associated with maximum inundation compared to dry states of pans. It can therefore be suggested that extended dry periods are threatening to microbially mediated processes in temporary wetlands, with implications to loss of biodiversity due to desiccation resulting in poor nutrient cycling.Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 202
Optimization of an intranasal levodopa nanocrystalline formulation for delivery to the brain
No full textThesis embargoed. Probable release date in 2025.Thesis (MSc (Pharm)) -- Faculty of Pharmacy, Pharmacy, 202
Analysis of corporate failures: a case study of two South African banks
Get PDFThis study analysed the factors that contributed to the failure of Venda Building Society Mutual Bank (VBS) and African Bank Limited and the impact it had on their key stakeholders. The specific objectives of this study were to evaluate African Bank and VBS bank's operational risk management processes and controls, the role of ethical failures at VBS bank and African Bank; and assess how the failures affected their stakeholders. The population sample of the study included African Bank and VBS. The study adopted a qualitative research method. Existing reports from both African Bank and VBS were used to collect data. The study adopted a thematic data analysis method, which includes data coding and the development of themes. The data analysis framework was derived from a defined set of research propositions and seven (7) themes were derived from this analysis method. The failure in operational controls of both banks and ineffective risk management structures including unethical conduct by the executive management and board of VBS bank, irregular financial transactions and weakened external auditing function resulted in an unaccountable executive relationship and reckless lending decision-making. This research study will expand on the existing body of knowledge on the failures and near-failures of banks in the South African banking sector. The South African banking industry and its regulatory bodies will be better equipped to strengthen their corporate governance in risk controls to mitigate future collapses and near collapses of banks.Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 202
The effectiveness of bank debt financing on the growth of small and medium enterprises (SMEs) in Namibia
Get PDFGlobally, SMEs are valued for their contribution to economic growth and development as well as for driving employment. To succeed, small firms require support especially in terms of obtaining funding and financial services that can enable them to meet day to day operational needs. Commercial banks play an important role for the financing of SMEs as small firms generally depend on bank loans to obtain external finance. However, despite the support and contribution, very little attention is given to the actual forms of finance used by small and medium-sized enterprises, the available finance made by lending institutions or investors and the relation between the use of the said debt finance and enterprise performance. Furthermore, several research studies carried out focusing on the effect of debt financing on performance of firms are inconsistent. Thus, this study sought to determine the effectiveness of bank debt finance on the growth of SMEs in Namibia. To achieve the objective of the study, it was important to have it rooted in the pragmatism paradigm; followed by both the deductive and inductive approaches. Interviews were conducted with the six SME owners and structured questionnaires were completed by the seven staff of the selected bank. The study used thematic analysis to analyze primary data from interviews by following three steps namely: reducing the data referred to as coding, analyzing data by creating patterns, and generating themes and drawing conclusion. Data from self-administered questionnaires was populated and textually analyzed aided by tables. The main findings of the study were that: (1) debt financing contributed to the growth and performance of SMEs as all firms under the study who made use of debt had experienced growth in terms of generated profits and acquired assets, (2) during the assessment and approving process, the bank looked at various lending factors and that collateral was not considered as prime to accessing funding, (3) the SMEs were not sufficiently funded and that there was no appropriate funding option for SMEs, (4) in terms of relationships, there was a lack of engagement and support between the bank and the SMEs. The support received from the bank was only in terms of lending.Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 202
Integrating music and mathematics for connecting across multiple constructs of fractional understanding: an RME task design journey
Get PDFTwo South African curricular aims: appreciating creativity in mathematics and developing conceptual understanding, motivated this study. Negative views towards mathematics and challenges in teaching and learning fractions at primary school level are reported in literature, with the part-whole construct of fractions often the sole teaching focus. Despite challenges in curriculum integration (high demands on teachers and diluting disciplines), benefits, such as motivation and creative thinking, are noted. I recognised music-mathematics integration as an opportune context for designing tasks to support learners in moving flexibly between the fraction as ratio, fraction as measure and part-whole constructs. Guided by Realistic Mathematics Education principles, I embarked on a participatory dual-design experiment in task design, grappling within three micro-Communities of Practice (micro-CoPs) and across two planes: the Design-Theorising Plane and the Grounded-Practice Plane. In the Design-Theorising Plane, I worked with my two doctoral supervisors, grappling with design obstacles and finding resolutions. COVID-19 restrictions shifted our meetings to online platforms, allowing documentation and analysis of the task design process through recording functions. In the Grounded-Practice Plane, I worked within two separate micro-CoPs, both at independent schools (eight and two participating teachers respectively). Data on the teachers’ interrogation and implementation of the designed tasks were obtained via formal and informal interviews. Their reflections informed ongoing adaptations to the task design. Data were analysed in a matrix I designed and via NVivo coding. Findings include both the product of the task design journey (eight music-mathematics lessons, resources, and representations) and the process (ten groupings of Obstacle-Resolution Cycles). Three key questions (relating to music-mathematics fidelity; to task simplification for implementation; and to appropriate music-mathematics representation) were used in addressing each Obstacle-Resolution Cycle. Designing tasks to teach the part-whole construct of fractions was relatively straightforward, but designing tasks to teach the fraction as ratio and fraction as measure constructs was more challenging. These constructs could not be conflated by superimposing the music and mathematical linear representations. Aligning them, however, allowed for moving flexibly between the constructs. The teachers reported that the integrated music-mathematics tasks and supporting resources enhanced their learners’ fractional problem-solving abilities, simultaneously promoting more positive learner dispositions towards mathematics.Thesis (PhD) -- Faculty of Education, Education, 202
Best practices in the use and exchange of microorganism biological control genetic resources
Get PDFThe Nagoya Protocol actions the third objective of the Convention on Biological Diversity and provides a framework to effectively implement the fair and equitable sharing of benefits arising out of the use of genetic resources. This includes microorganisms used as biological control agents. Thus biological control practitioners must comply with access and benefit-sharing regulations that are implemented by countries providing microbial biological control agents. A review of best practices and guidance for the use and exchange of microorganisms used for biological control has been prepared by the IOBC Global Commission on Biological Control and Access and Benefit-Sharing to demonstrate commitment to comply with access and benefit-sharing requirements, and to reassure the international community that biological control is a very successful and environmentally safe pest management strategy that uses biological resources responsibly and sustainably. We propose that best practices include the following elements: collaboration to facilitate information exchange about the availability of microbial biological control agents and where they may be sourced; freely sharing available knowledge in databases about successes and failures; collaborative research with provider countries to develop capacity; and production technology transfer to provide economic opportunities. We recommend the use of model concept agreements for accessing microorganisms for scientific research and non-commercial release into nature where access and benefit-sharing regulations exist and where regulations are not restrictive or do not exist. We also recommend a model agreement for deposition of microbial biological control agents into culture collections