Comparative study of the effect of iloprost on neuroinflammatory changes in c8-b4 microglial cells and murine model of trypanosomiasis
- Authors: Jacobs, Ashleigh
- Date: 2024-12
- Subjects: Neuroimmunology , DNA -- Methylation , Nervous system -- Degeneration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68895 , vital:77160
- Description: Neurodegenerative conditions significantly impact well-being and quality of life in individuals with major symptoms including mood disorders, cognitive decline, and psychiatric disturbances, often resulting from neuroinflammation triggered by immune responses to bacterial or parasitic infections such as gram-negative bacteria or Human African Trypanosomiasis. Microglia play a crucial role in both neurotoxicity and cellular processes involved in restoring the neural health. Exploring the therapeutic potential of prostacyclin and its analogues in regulating microglia responses to inflammatory insult and treating Trypanosoma brucei (T.b) infection remains an unexplored area. The aim of this study was to assess the potential neuroprotective effects of Iloprost through comparative analysis of neuroinflammatory responses in both microglial cells exposed to lipopolysaccharide (LPS) and mouse brains infected with T.b brucei. In phase I of this study both resting and LPS treated C8-B4 microglial cells were exposed to varying concentrations of Iloprost. The effects of Iloprost on LPS-induced inflammation were analysed using immunofluorescence to detect microglial activation and differentiate between pro and anti-inflammatory phenotypes. Furthermore, pro and anti-inflammatory cytokine secretion was determined using an ELISA, in addition gene expression analysis was carried out using quantitative polymerase chain reaction (qPCR). Also, DNA methylation status of C8-B4 cells exposed to LPS challenge alone or in combination with various concentrations of Iloprost were determined using bisulfite sequencing technique followed by qPCR. In phase II of the study, a total of twenty-four Albino Swiss male mice (8-10 weeks old) were divided into four treatment groups with 6 mice in each group. All treatment groups except the non-infected control were inoculated with the T.b brucei parasite. One group received a single intraperitoneal injection of Diminazene aceturate (4 mg kg-1)while the remaining group received repeated intraperitoneal injections of Iloprost (200 μg kg-1). On day ten of the study, mouse brains were removed on ice using forceps. The hippocampal tissues were dissected out and processed for quantification of gene expression changes in pro and anti-inflammatory cytokines. Overall, the findings of this study indicate that LPS-induced pro-inflammatory cytokine, TNF-α and IL-1β, secretion and gene expression is down-regulated in C8-B4 microglial cells treated with Iloprost. Furthermore, there was a significant up-regulation in the expression of anti-inflammatory genes, particularly ARG-1, CD206, BDNF and CREB in response to Iloprost treatment following LPS-induced inflammation. This study is also the first to confirm M2 microglial polarization with Iloprost treatment in both resting and LPS treated cells. However, hypermethylation at CREB and BDNF promoter regions was observed 24 hours after Iloprost treatment. Additionally, Iloprost reversed hypomethylation at the BDNF promoter region that had been induced by LPS treatment. The rodent model also indicated a downregulation in the pro-inflammatory cytokine, IL-1β, expression and upregulation of BDNF transcription in T.b brucei infected mice treated with repeated doses of Iloprost. In conclusion, determining the immunomodulatory roles of Iloprost in both in vitro and in vivo models of neuroinflammation could assist in the development of alternative therapy for neurodegenerative disease. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Jacobs, Ashleigh
- Date: 2024-12
- Subjects: Neuroimmunology , DNA -- Methylation , Nervous system -- Degeneration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68895 , vital:77160
- Description: Neurodegenerative conditions significantly impact well-being and quality of life in individuals with major symptoms including mood disorders, cognitive decline, and psychiatric disturbances, often resulting from neuroinflammation triggered by immune responses to bacterial or parasitic infections such as gram-negative bacteria or Human African Trypanosomiasis. Microglia play a crucial role in both neurotoxicity and cellular processes involved in restoring the neural health. Exploring the therapeutic potential of prostacyclin and its analogues in regulating microglia responses to inflammatory insult and treating Trypanosoma brucei (T.b) infection remains an unexplored area. The aim of this study was to assess the potential neuroprotective effects of Iloprost through comparative analysis of neuroinflammatory responses in both microglial cells exposed to lipopolysaccharide (LPS) and mouse brains infected with T.b brucei. In phase I of this study both resting and LPS treated C8-B4 microglial cells were exposed to varying concentrations of Iloprost. The effects of Iloprost on LPS-induced inflammation were analysed using immunofluorescence to detect microglial activation and differentiate between pro and anti-inflammatory phenotypes. Furthermore, pro and anti-inflammatory cytokine secretion was determined using an ELISA, in addition gene expression analysis was carried out using quantitative polymerase chain reaction (qPCR). Also, DNA methylation status of C8-B4 cells exposed to LPS challenge alone or in combination with various concentrations of Iloprost were determined using bisulfite sequencing technique followed by qPCR. In phase II of the study, a total of twenty-four Albino Swiss male mice (8-10 weeks old) were divided into four treatment groups with 6 mice in each group. All treatment groups except the non-infected control were inoculated with the T.b brucei parasite. One group received a single intraperitoneal injection of Diminazene aceturate (4 mg kg-1)while the remaining group received repeated intraperitoneal injections of Iloprost (200 μg kg-1). On day ten of the study, mouse brains were removed on ice using forceps. The hippocampal tissues were dissected out and processed for quantification of gene expression changes in pro and anti-inflammatory cytokines. Overall, the findings of this study indicate that LPS-induced pro-inflammatory cytokine, TNF-α and IL-1β, secretion and gene expression is down-regulated in C8-B4 microglial cells treated with Iloprost. Furthermore, there was a significant up-regulation in the expression of anti-inflammatory genes, particularly ARG-1, CD206, BDNF and CREB in response to Iloprost treatment following LPS-induced inflammation. This study is also the first to confirm M2 microglial polarization with Iloprost treatment in both resting and LPS treated cells. However, hypermethylation at CREB and BDNF promoter regions was observed 24 hours after Iloprost treatment. Additionally, Iloprost reversed hypomethylation at the BDNF promoter region that had been induced by LPS treatment. The rodent model also indicated a downregulation in the pro-inflammatory cytokine, IL-1β, expression and upregulation of BDNF transcription in T.b brucei infected mice treated with repeated doses of Iloprost. In conclusion, determining the immunomodulatory roles of Iloprost in both in vitro and in vivo models of neuroinflammation could assist in the development of alternative therapy for neurodegenerative disease. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Construction material waste control success model for the construction industry
- Authors: Musah, Abdul Razak
- Date: 2024-12
- Subjects: Construction industry -- Materials management , Construction industry -- Management , Construction industry -- Environmental aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68796 , vital:77114
- Description: Economic sustainability and reconstruction in many economies rely heavily on the construction sector and remain strategic tools for governments and industries worldwide. Excessive construction costs and materials waste among some construction companies are rampant in the construction sector. Most of this waste is poorly managed, thus triggering significant project failure problems, leading to the project stakeholders losing the value of their investment. This concern advocate for effective control of construction material to avoid wastage. The primary objective of this study was to develop a Construction Waste Material Control (CWMC) model to be used by construction project professionals throughout the Project Management (PM) phases: initiation, planning, execution, monitoring, control and closure. Significant literature on construction materials waste, Project Management (PM) processes, and project performance regarding poor waste management and project failure was reviewed. This literature review was conducted to identify factors affecting Construction Waste Material Control (CWMC). These factors were identified and defined together with their respective contributions to the model. A quantitative survey instrument (questionnaire) was used to obtain information from construction sector professionals. A total of 213 questionnaire were received and administered for the study. Structural Equation Model (SEM) SEM was used to analyse the questionnaire data, and thereby assisting the research to clearly define latent constructs statistically significant to the (CWMC) model. The finding was that, the factors identified to have impact on CWMC are Project Initiation Phase Tools (PIPTs), Project Planning Phase Tools (PPPTs), project failure/success factors (PFFs), Project Execution Phase Tools (PEPTs), Project Monitoring and Control Phase Tools (PMCPTs), Construction waste material Control (CWMC) policy and Project Management (PM) competence. The supported hypotheses also authenticated these factors. Introducing the model into the construction sector provides another dimension to CWMC. By establishing the aforementioned factors, the model gives construction professionals precise CWMC predictive accuracy. As the model reliability test of 0.734 to 0.972 satisfied the theoretical threshold and goodness of fit of 0.912 of Normed fit index respectively. The model is the first of its kind and contributes significantly to the construction sector’s existing body of knowledge. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Musah, Abdul Razak
- Date: 2024-12
- Subjects: Construction industry -- Materials management , Construction industry -- Management , Construction industry -- Environmental aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68796 , vital:77114
- Description: Economic sustainability and reconstruction in many economies rely heavily on the construction sector and remain strategic tools for governments and industries worldwide. Excessive construction costs and materials waste among some construction companies are rampant in the construction sector. Most of this waste is poorly managed, thus triggering significant project failure problems, leading to the project stakeholders losing the value of their investment. This concern advocate for effective control of construction material to avoid wastage. The primary objective of this study was to develop a Construction Waste Material Control (CWMC) model to be used by construction project professionals throughout the Project Management (PM) phases: initiation, planning, execution, monitoring, control and closure. Significant literature on construction materials waste, Project Management (PM) processes, and project performance regarding poor waste management and project failure was reviewed. This literature review was conducted to identify factors affecting Construction Waste Material Control (CWMC). These factors were identified and defined together with their respective contributions to the model. A quantitative survey instrument (questionnaire) was used to obtain information from construction sector professionals. A total of 213 questionnaire were received and administered for the study. Structural Equation Model (SEM) SEM was used to analyse the questionnaire data, and thereby assisting the research to clearly define latent constructs statistically significant to the (CWMC) model. The finding was that, the factors identified to have impact on CWMC are Project Initiation Phase Tools (PIPTs), Project Planning Phase Tools (PPPTs), project failure/success factors (PFFs), Project Execution Phase Tools (PEPTs), Project Monitoring and Control Phase Tools (PMCPTs), Construction waste material Control (CWMC) policy and Project Management (PM) competence. The supported hypotheses also authenticated these factors. Introducing the model into the construction sector provides another dimension to CWMC. By establishing the aforementioned factors, the model gives construction professionals precise CWMC predictive accuracy. As the model reliability test of 0.734 to 0.972 satisfied the theoretical threshold and goodness of fit of 0.912 of Normed fit index respectively. The model is the first of its kind and contributes significantly to the construction sector’s existing body of knowledge. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, School of Built Environment and Civil Engineering, 2024
- Full Text:
- Date Issued: 2024-12
Development of density-dependent and density-independent competition models to understand single tree growth responses in eucalyptus stands
- Authors: Kepe, Lulama Patrick
- Date: 2024-12
- Subjects: Forests and forestry -- Mathematical models , Trees -- Growth -- Mathematical models , Eucalyptus grandis
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68906 , vital:77161
- Description: In commercial forest production, predicted yields based on mensuration recommendations are seldom realized, and minimal silvicultural standards based on results from trial blocks do not account for the relationship between initial planting density and final stocking. Growth models designed to investigate management options must employ competition indices to provide reliable predictions under extreme silviculture. The competition a tree experiences until the day of harvest is a strong driver for quality and volume of timber. Hence, this turns the regulation of competition into an integral part of silviculture. According to Little et al. (2003), it is known that, at some stage after canopy closure, individual trees in a stand will begin to compete for resources. To investigate competition amongst individual trees, a re-purposed Bayesian mixed effects model, similar in characteristics to a Sire model used for estimating breeding values, is proposed. In animal breeding models, the Sire Model allows for the inclusion of a numerator relationship matrix containing inbreeding coefficients. In a similar way, documented competition indices are included in the model in an attempt to estimate posterior probabilities of specifically selected individual trees being the strongest growers during different stages in the tree growth cycle. Estimated tree growth indices were determined and used to make probability statements in order to rank the individually selected trees based on the amount of growth observed. A tree growth index is a measurement of a tree’s average growth performance in relation to the average growth performance of all trees on the same plot. As different competition indices are introduced into the model, changes in the probabilities are observed and compared to what is visually observed on the plot, i.e. if the tree with the highest probability of being the strongest grower, is actually not necessarily the largest tree of the group of selected trees, but rather the tree that presented the largest amount of growth of the selected group of trees during that specific growth season. From a randomly selected plot, a group of neighboring trees were randomly selected. Four specifically selected target trees were then identified from this group of 25 selected trees, and analyzed. For this discussion, for example, from our randomly selected group of 25 neighboring trees, tree 54, tree 56, tree 86, and tree 88 were specifically selected for further analysis. For these specifically selected trees, marginal posterior densities for the variance components and random effects were then estimated using the Gibbs Sampler, where competition between the trees was assumed present, as well as for the case where it was assumed that no competition takes place between the individually selected trees. In the latter case, an identity matrix was utilized in the Gibbs sampling algorithm where it was assumed that there is no competition between the trees. Both a distance independent competition index (Lorimer,1983), and a distance dependent index (Hegyi, 1974), were used to generate the numerator relationship matrix A that was used by the Gibbs sampling algorithm in the case where competition was assumed between individual trees. Also a new distance dependent index was proposed and tested in this study as well. Results from the selected plot, with a 1500 stems per hectare (sph) density, indicated that there were no significant differences in the average growth between these selected trees. However, the marginal posterior densities of the fixed effects indicated that there was a significant difference in the average growth rates between the base level conditions and other levels determined for each of these fixed effect factors for the selected trees, since their 95% equal tails credibility intervals, did not contain zero. This therefore indicated that the specific treatment applied on the plot, had a significant effect on the individual tree growth. Results when competition was assumed present, revealed that the estimated marginal posterior densities for the error variance as well as tree variance, were severely positively skewed. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Science & Management, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Kepe, Lulama Patrick
- Date: 2024-12
- Subjects: Forests and forestry -- Mathematical models , Trees -- Growth -- Mathematical models , Eucalyptus grandis
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68906 , vital:77161
- Description: In commercial forest production, predicted yields based on mensuration recommendations are seldom realized, and minimal silvicultural standards based on results from trial blocks do not account for the relationship between initial planting density and final stocking. Growth models designed to investigate management options must employ competition indices to provide reliable predictions under extreme silviculture. The competition a tree experiences until the day of harvest is a strong driver for quality and volume of timber. Hence, this turns the regulation of competition into an integral part of silviculture. According to Little et al. (2003), it is known that, at some stage after canopy closure, individual trees in a stand will begin to compete for resources. To investigate competition amongst individual trees, a re-purposed Bayesian mixed effects model, similar in characteristics to a Sire model used for estimating breeding values, is proposed. In animal breeding models, the Sire Model allows for the inclusion of a numerator relationship matrix containing inbreeding coefficients. In a similar way, documented competition indices are included in the model in an attempt to estimate posterior probabilities of specifically selected individual trees being the strongest growers during different stages in the tree growth cycle. Estimated tree growth indices were determined and used to make probability statements in order to rank the individually selected trees based on the amount of growth observed. A tree growth index is a measurement of a tree’s average growth performance in relation to the average growth performance of all trees on the same plot. As different competition indices are introduced into the model, changes in the probabilities are observed and compared to what is visually observed on the plot, i.e. if the tree with the highest probability of being the strongest grower, is actually not necessarily the largest tree of the group of selected trees, but rather the tree that presented the largest amount of growth of the selected group of trees during that specific growth season. From a randomly selected plot, a group of neighboring trees were randomly selected. Four specifically selected target trees were then identified from this group of 25 selected trees, and analyzed. For this discussion, for example, from our randomly selected group of 25 neighboring trees, tree 54, tree 56, tree 86, and tree 88 were specifically selected for further analysis. For these specifically selected trees, marginal posterior densities for the variance components and random effects were then estimated using the Gibbs Sampler, where competition between the trees was assumed present, as well as for the case where it was assumed that no competition takes place between the individually selected trees. In the latter case, an identity matrix was utilized in the Gibbs sampling algorithm where it was assumed that there is no competition between the trees. Both a distance independent competition index (Lorimer,1983), and a distance dependent index (Hegyi, 1974), were used to generate the numerator relationship matrix A that was used by the Gibbs sampling algorithm in the case where competition was assumed between individual trees. Also a new distance dependent index was proposed and tested in this study as well. Results from the selected plot, with a 1500 stems per hectare (sph) density, indicated that there were no significant differences in the average growth between these selected trees. However, the marginal posterior densities of the fixed effects indicated that there was a significant difference in the average growth rates between the base level conditions and other levels determined for each of these fixed effect factors for the selected trees, since their 95% equal tails credibility intervals, did not contain zero. This therefore indicated that the specific treatment applied on the plot, had a significant effect on the individual tree growth. Results when competition was assumed present, revealed that the estimated marginal posterior densities for the error variance as well as tree variance, were severely positively skewed. , Thesis (PhD) -- Faculty of Science, School of Natural Resource Science & Management, 2024
- Full Text:
- Date Issued: 2024-12
Experiences of accoucheurs caring for women during confinement in public maternity units in the O.R. Tambo District Municipality
- Authors: Wabane, Malibongwe
- Date: 2024-12
- Subjects: Midwifery -- South Africa -- Eastern Cape , Labor (Obstetrics) -- South Africa -- Eastern Cape , Hospital care -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69782 , vital:78034
- Description: Midwifery is a health science profession that deals with women in their confinement period, including the caring of new-borns. Historically, the midwifery profession has evolved from being a female-dominated profession to an occupation followed by both males and females. However, accoucheurs working in public maternity units face various challenges, such as a lack of support and discrimination from their female counterparts and women during confinement. These challenges are based mainly on tradition, religion, and the history of midwifery, a female-dominant profession. The potential effects of these challenges can be seen when women during confinement refuse maternal care from accoucheurs. As a result of this prejudice, accoucheurs may be unable to practice their midwifery skills and may choose other disciplines involving less intimate care. Such acts of refusal of care by women during confinement and these various challenges faced by accoucheurs in public maternity units are common in rural areas. The O.R. Tambo District Municipality (ORTDM) comprises predominantly of rural areas where culture and tradition play an essential role in the community’s life. This study employed a qualitative research design with an explorative, descriptive, and contextual approach to gain a deeper understanding of the experiences of accoucheurs caring for women during confinement in public maternity units in the ORTDM. The purpose of this study was to explore and describe the experiences of accoucheurs caring for women during confinement in public maternity units in the ORTDM to make recommendations to nursing managers regarding the provision of optimal support to accoucheurs working in the rural Eastern Cape. The target population of the study was all accoucheurs working in public maternity units in the ORTDM. Snowball sampling, a non-probability sampling method, was used to select participants who met the inclusion criteria and were voluntarily willing to participate in the study. The data collection method used was one-on-one semistructured interviews, which were also captured using a digital voice recorder. Field notes were used during data collection to enhance the researcher’s understanding of accoucheurs’ nonverbal experiences. The sample size, which was 12 accoucheurs, was determined by data saturation. Data was transcribed verbatim, and Braun and Clark’s (2006) steps of reflexive thematic analysis (RTA) were used as a framework for data analysis. Lincoln and Guba’s model of trustworthiness was used to maintain the quality of the study by employing credibility, transferability, confirmability, and dependability (Lincoln and Guba, 1985). The ethical principles that guided this study with human participants were the principles of respect for persons, beneficence, non-maleficence, and justice as outlined in the Belmont Report and its application (2015:14) Three main themes emerged from the data analysis, namely: • Theme 1: Accoucheurs experienced specific factors that enabled them to care for women during confinement in public maternity units. • Theme 2: Accoucheurs identified barriers that disabled them in caring for women during confinement in public maternity units. • Theme 3: Recommendations for nurse managers by accoucheurs to optimize their ability to care for women during confinement in public maternity units. Direct quotations from the raw data and relevant literature supported the research study results and were discussed in-depth in Chapter Four. Various recommendations were discussed in Chapter Five of this study that present options for nurse managers to optimize the support for accoucheurs who were caring for women during confinement in public maternity units.Midwifery is a health science profession that deals with women in their confinement period, including the caring of new-borns. Historically, the midwifery profession has evolved from being a female-dominated profession to an occupation followed by both males and females. However, accoucheurs working in public maternity units face various challenges, such as a lack of support and discrimination from their female counterparts and women during confinement. These challenges are based mainly on tradition, religion, and the history of midwifery, a female-dominant profession. The potential effects of these challenges can be seen when women during confinement refuse maternal care from accoucheurs. As a result of this prejudice, accoucheurs may be unable to practice their midwifery skills and may choose other disciplines involving less intimate care. Such acts of refusal of care by women during confinement and these various challenges faced by accoucheurs in public maternity units are common in rural areas. The O.R. Tambo District Municipality (ORTDM) comprises predominantly of rural areas where culture and tradition play an essential role in the community’s life. This study employed a qualitative research design with an explorative, descriptive, and contextual approach to gain a deeper understanding of the experiences of accoucheurs caring for women during confinement in public maternity units in the ORTDM. The purpose of this study was to explore and describe the experiences of accoucheurs caring for women during confinement in public maternity units in the ORTDM to make recommendations to nursing managers regarding the provision of optimal support to accoucheurs working in the rural Eastern Cape. The target population of the study was all accoucheurs working in public maternity units in the ORTDM. Snowball sampling, a non-probability sampling method, was used to select participants who met the inclusion criteria and were voluntarily willing to participate in the study. The data collection method used was one-on-one semistructured interviews, which were also captured using a digital voice recorder. Field notes were used during data collection to enhance the researcher’s understanding of accoucheurs’ nonverbal experiences. The sample size, which was 12 accoucheurs, was determined by data saturation. Data was transcribed verbatim, and Braun and Clark’s (2006) steps of reflexive thematic analysis (RTA) were used as a framework for data analysis. Lincoln and Guba’s model of trustworthiness was used to maintain the quality of the study by employing credibility, transferability, confirmability, and dependability (Lincoln and Guba, 1985). The ethical principles that guided this study with human participants were the principles of respect for persons, beneficence, non-maleficence, and justice as outlined in the Belmont Report and its application (2015:14) Three main themes emerged from the data analysis, namely: • Theme 1: Accoucheurs experienced specific factors that enabled them to care for women during confinement in public maternity units. • Theme 2: Accoucheurs identified barriers that disabled them in caring for women during confinement in public maternity units. • Theme 3: Recommendations for nurse managers by accoucheurs to optimize their ability to care for women during confinement in public maternity units. Direct quotations from the raw data and relevant literature supported the research study results and were discussed in-depth in Chapter Four. Various recommendations were discussed in Chapter Five of this study that present options for nurse managers to optimize the support for accoucheurs who were caring for women during confinement in public maternity units. , Thesis (MCur) -- Faculty of Health Sciences, School of Clinical Care & Medicinal Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Wabane, Malibongwe
- Date: 2024-12
- Subjects: Midwifery -- South Africa -- Eastern Cape , Labor (Obstetrics) -- South Africa -- Eastern Cape , Hospital care -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69782 , vital:78034
- Description: Midwifery is a health science profession that deals with women in their confinement period, including the caring of new-borns. Historically, the midwifery profession has evolved from being a female-dominated profession to an occupation followed by both males and females. However, accoucheurs working in public maternity units face various challenges, such as a lack of support and discrimination from their female counterparts and women during confinement. These challenges are based mainly on tradition, religion, and the history of midwifery, a female-dominant profession. The potential effects of these challenges can be seen when women during confinement refuse maternal care from accoucheurs. As a result of this prejudice, accoucheurs may be unable to practice their midwifery skills and may choose other disciplines involving less intimate care. Such acts of refusal of care by women during confinement and these various challenges faced by accoucheurs in public maternity units are common in rural areas. The O.R. Tambo District Municipality (ORTDM) comprises predominantly of rural areas where culture and tradition play an essential role in the community’s life. This study employed a qualitative research design with an explorative, descriptive, and contextual approach to gain a deeper understanding of the experiences of accoucheurs caring for women during confinement in public maternity units in the ORTDM. The purpose of this study was to explore and describe the experiences of accoucheurs caring for women during confinement in public maternity units in the ORTDM to make recommendations to nursing managers regarding the provision of optimal support to accoucheurs working in the rural Eastern Cape. The target population of the study was all accoucheurs working in public maternity units in the ORTDM. Snowball sampling, a non-probability sampling method, was used to select participants who met the inclusion criteria and were voluntarily willing to participate in the study. The data collection method used was one-on-one semistructured interviews, which were also captured using a digital voice recorder. Field notes were used during data collection to enhance the researcher’s understanding of accoucheurs’ nonverbal experiences. The sample size, which was 12 accoucheurs, was determined by data saturation. Data was transcribed verbatim, and Braun and Clark’s (2006) steps of reflexive thematic analysis (RTA) were used as a framework for data analysis. Lincoln and Guba’s model of trustworthiness was used to maintain the quality of the study by employing credibility, transferability, confirmability, and dependability (Lincoln and Guba, 1985). The ethical principles that guided this study with human participants were the principles of respect for persons, beneficence, non-maleficence, and justice as outlined in the Belmont Report and its application (2015:14) Three main themes emerged from the data analysis, namely: • Theme 1: Accoucheurs experienced specific factors that enabled them to care for women during confinement in public maternity units. • Theme 2: Accoucheurs identified barriers that disabled them in caring for women during confinement in public maternity units. • Theme 3: Recommendations for nurse managers by accoucheurs to optimize their ability to care for women during confinement in public maternity units. Direct quotations from the raw data and relevant literature supported the research study results and were discussed in-depth in Chapter Four. Various recommendations were discussed in Chapter Five of this study that present options for nurse managers to optimize the support for accoucheurs who were caring for women during confinement in public maternity units.Midwifery is a health science profession that deals with women in their confinement period, including the caring of new-borns. Historically, the midwifery profession has evolved from being a female-dominated profession to an occupation followed by both males and females. However, accoucheurs working in public maternity units face various challenges, such as a lack of support and discrimination from their female counterparts and women during confinement. These challenges are based mainly on tradition, religion, and the history of midwifery, a female-dominant profession. The potential effects of these challenges can be seen when women during confinement refuse maternal care from accoucheurs. As a result of this prejudice, accoucheurs may be unable to practice their midwifery skills and may choose other disciplines involving less intimate care. Such acts of refusal of care by women during confinement and these various challenges faced by accoucheurs in public maternity units are common in rural areas. The O.R. Tambo District Municipality (ORTDM) comprises predominantly of rural areas where culture and tradition play an essential role in the community’s life. This study employed a qualitative research design with an explorative, descriptive, and contextual approach to gain a deeper understanding of the experiences of accoucheurs caring for women during confinement in public maternity units in the ORTDM. The purpose of this study was to explore and describe the experiences of accoucheurs caring for women during confinement in public maternity units in the ORTDM to make recommendations to nursing managers regarding the provision of optimal support to accoucheurs working in the rural Eastern Cape. The target population of the study was all accoucheurs working in public maternity units in the ORTDM. Snowball sampling, a non-probability sampling method, was used to select participants who met the inclusion criteria and were voluntarily willing to participate in the study. The data collection method used was one-on-one semistructured interviews, which were also captured using a digital voice recorder. Field notes were used during data collection to enhance the researcher’s understanding of accoucheurs’ nonverbal experiences. The sample size, which was 12 accoucheurs, was determined by data saturation. Data was transcribed verbatim, and Braun and Clark’s (2006) steps of reflexive thematic analysis (RTA) were used as a framework for data analysis. Lincoln and Guba’s model of trustworthiness was used to maintain the quality of the study by employing credibility, transferability, confirmability, and dependability (Lincoln and Guba, 1985). The ethical principles that guided this study with human participants were the principles of respect for persons, beneficence, non-maleficence, and justice as outlined in the Belmont Report and its application (2015:14) Three main themes emerged from the data analysis, namely: • Theme 1: Accoucheurs experienced specific factors that enabled them to care for women during confinement in public maternity units. • Theme 2: Accoucheurs identified barriers that disabled them in caring for women during confinement in public maternity units. • Theme 3: Recommendations for nurse managers by accoucheurs to optimize their ability to care for women during confinement in public maternity units. Direct quotations from the raw data and relevant literature supported the research study results and were discussed in-depth in Chapter Four. Various recommendations were discussed in Chapter Five of this study that present options for nurse managers to optimize the support for accoucheurs who were caring for women during confinement in public maternity units. , Thesis (MCur) -- Faculty of Health Sciences, School of Clinical Care & Medicinal Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Exploiting continuous flow technology to develop synthetic processes for active pharmaceutical ingredients: prilocaine and betrixaban
- Authors: Sagandira, Mellisa Brenda
- Date: 2024-12
- Subjects: Pharmaceutical technology , Drug development , Pharmaceutical biotechnology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69464 , vital:77259
- Description: The dilemma of providing affordable health care has long haunted African countries due to the continuously growing disease burden as the population increases. Africa accounts for only 3 % of global drug production and imports over 90 % of its life saving medicines at a yearly cost of US$14 billion according to the African Development Bank (AfDB). Attaining Africa’s Agenda 2063, Universal Health Coverage (UHC) and Sustainable development Goal 3 (SDG3) aspirations of ensuring healthy and well-nourished citizens remain difficult given this situation. This over-dependence on imports has led to drug shortages, high pricing, poor quality medicines and unguaranteed supply chains, thus there still remains an unmet need. The advent of the COVID-19 pandemic worsened this situation as many countries curbed exports resulting in a crisis across the continent. Africa experienced high demand of medicines compared to prepandemic level, which threatened the health care of the continent. This situation can be addressed by establishment of local pharmaceutical manufacturing capability through adoption of advanced manufacturing technologies such as continuous flow chemistry. In this research, we therefore seek to exploit continuous flow chemistry, an enabling technology to develop safe and efficient synthetic processes for active pharmaceutical ingredients: prilocaine and betrixaban as case studies. To the best of our knowledge there is no reported work on synthetic processes towards prilocaine and betrixaban under continuous flow conditions, thus this research extensively unearthed interesting continuous flow processes towards these APIs. In a broader view, establishment of local APIs production will ease Africa’s over-dependence on imports, which will in turn address issues such as drug shortages, poor quality and high pricing. This work aims to demonstrate how continuous flow technology can be useful for the establishment of local APIs manufacturing, which will inherently revolutionize medicines availability, affordability and accessibility to the greater population. Chapter one begins with a brief overview on Africa’s disease burden and pharmaceutical supply chain. Continuous flow chemistry is introduced with its benefits and limitations discussed. Lastly a mini review of examples of APIs synthesised in continuous flow is presented. In chapter two, we demonstrate how continuous flow technology can be exploited to develop synthetic processes towards prilocaine as our first case study. This chapter clearly demonstrates how highly exothermic nitration reactions can be safely handled by using continuous flow systems. Additionally, the use of a micro structured mixer facilitated biphasic nitration of toluene to be carried out with enhanced mass transfer, which inherently led to improved selectivity of ortho-nitrotoluene (preferred isomer) to 79 % compared to 59 % achieved in batch mode. A two-step synthesis of ortho-toluidine via biphasic nitration of toluene and nitroreduction was demonstrated with the incorporation of a Zaiput liquid/liquid separator to facilitate in-line separation. Comprehensive optimisation studies were carried out in flow. Prilocaine was synthesised in 74 % overall yield in a 13.6 min residence time for all processes. In chapter three, we demonstrate how continuous flow technology can be exploited to develop synthetic processes towards betrixaban. Synthetic routes towards betrixaban feature two amide bond formation transformations. Pleasingly, we explored multistep chemistry to develop amide synthesis protocols in flow without interruption for work up and isolation. An overall yield of 92 % was achieved to get to key intermediate to betrixaban in 8 min total residence time. Chapter four demonstrates the robustness of developed amide synthesis protocols, a key transformation in synthetic routes towards prilocaine and betrixaban in continuous flow systems. A total of 22 amides were synthesised via flow multistep processes with isolated yields greater than 82 %. All the compounds were characterized using infrared spectroscopy (IR), and nuclear magnetic resonance (NMR). Quantification of the reaction mixtures were carried out using highperformance liquid chromatography (HPLC) and gas chromatography (GC). , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Sagandira, Mellisa Brenda
- Date: 2024-12
- Subjects: Pharmaceutical technology , Drug development , Pharmaceutical biotechnology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69464 , vital:77259
- Description: The dilemma of providing affordable health care has long haunted African countries due to the continuously growing disease burden as the population increases. Africa accounts for only 3 % of global drug production and imports over 90 % of its life saving medicines at a yearly cost of US$14 billion according to the African Development Bank (AfDB). Attaining Africa’s Agenda 2063, Universal Health Coverage (UHC) and Sustainable development Goal 3 (SDG3) aspirations of ensuring healthy and well-nourished citizens remain difficult given this situation. This over-dependence on imports has led to drug shortages, high pricing, poor quality medicines and unguaranteed supply chains, thus there still remains an unmet need. The advent of the COVID-19 pandemic worsened this situation as many countries curbed exports resulting in a crisis across the continent. Africa experienced high demand of medicines compared to prepandemic level, which threatened the health care of the continent. This situation can be addressed by establishment of local pharmaceutical manufacturing capability through adoption of advanced manufacturing technologies such as continuous flow chemistry. In this research, we therefore seek to exploit continuous flow chemistry, an enabling technology to develop safe and efficient synthetic processes for active pharmaceutical ingredients: prilocaine and betrixaban as case studies. To the best of our knowledge there is no reported work on synthetic processes towards prilocaine and betrixaban under continuous flow conditions, thus this research extensively unearthed interesting continuous flow processes towards these APIs. In a broader view, establishment of local APIs production will ease Africa’s over-dependence on imports, which will in turn address issues such as drug shortages, poor quality and high pricing. This work aims to demonstrate how continuous flow technology can be useful for the establishment of local APIs manufacturing, which will inherently revolutionize medicines availability, affordability and accessibility to the greater population. Chapter one begins with a brief overview on Africa’s disease burden and pharmaceutical supply chain. Continuous flow chemistry is introduced with its benefits and limitations discussed. Lastly a mini review of examples of APIs synthesised in continuous flow is presented. In chapter two, we demonstrate how continuous flow technology can be exploited to develop synthetic processes towards prilocaine as our first case study. This chapter clearly demonstrates how highly exothermic nitration reactions can be safely handled by using continuous flow systems. Additionally, the use of a micro structured mixer facilitated biphasic nitration of toluene to be carried out with enhanced mass transfer, which inherently led to improved selectivity of ortho-nitrotoluene (preferred isomer) to 79 % compared to 59 % achieved in batch mode. A two-step synthesis of ortho-toluidine via biphasic nitration of toluene and nitroreduction was demonstrated with the incorporation of a Zaiput liquid/liquid separator to facilitate in-line separation. Comprehensive optimisation studies were carried out in flow. Prilocaine was synthesised in 74 % overall yield in a 13.6 min residence time for all processes. In chapter three, we demonstrate how continuous flow technology can be exploited to develop synthetic processes towards betrixaban. Synthetic routes towards betrixaban feature two amide bond formation transformations. Pleasingly, we explored multistep chemistry to develop amide synthesis protocols in flow without interruption for work up and isolation. An overall yield of 92 % was achieved to get to key intermediate to betrixaban in 8 min total residence time. Chapter four demonstrates the robustness of developed amide synthesis protocols, a key transformation in synthetic routes towards prilocaine and betrixaban in continuous flow systems. A total of 22 amides were synthesised via flow multistep processes with isolated yields greater than 82 %. All the compounds were characterized using infrared spectroscopy (IR), and nuclear magnetic resonance (NMR). Quantification of the reaction mixtures were carried out using highperformance liquid chromatography (HPLC) and gas chromatography (GC). , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Exploring children’s understandings of gender using critical literacy in a reading club
- Jansen, Lincoln Lee, Surname, name
- Authors: Jansen, Lincoln Lee , Surname, name
- Date: 2024-12
- Subjects: Book clubs (Discussion groups) -- South Africa , Literacy -- Study and teaching (Elementary) , Literacy -- Study and teaching (Middle school)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68333 , vital:76976
- Description: School literacy practices have always favoured traditional, gender stereotypical portrayals of characters in books. These portrayals are not troublesome as it helps children build a sense of identity. However, these portrayals often fail to represent people in more diverse ways and thus does not reflect how societies have progressed. These narrow portrayals are also often limiting and do not take into consideration people’s personal interests which can lead to them being ostracised and marginalised. The People’s Republic of China is the context for this study where traditional, conservative views are upheld about ways of being and doing for males and females. This is a qualitative study within the interpretivist paradigm which recognised the individual perceptions of participants within their specific sociocultural context. By establishing a reading club as a Third Space for literacy engagement, this study sought to explore how grade 2 learners at a school in Beijing, China responded to traditional and diverse portrayals of characters in books. This study regarded the establishment of a reading club as an empowering practice as it allowed a safe space for the participants to freely share their deliberations about ways of being in the world. Coupled with critical literacy as a practice, participants took a critical stance in instances of gender bias and injustices and in doing so, allowed them to accentuate their morality. Findings of this study suggest that the Chinese participants had very flexible ideas about ways of being and doing in the world as long as these did not conflict with their understandings of the law. Participants also upheld that gender performances and gendered behaviour are open to all with impunity. The findings of this study also highlight the importance of providing diverse literature to children as this helps them to deal with, and examine, issues they might not ordinarily encounter in a safe way and in doing so, expand their worldviews and cultivate empathy. , Thesis (PhD) -- Faculty of Education, School of Primary Schooling, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Jansen, Lincoln Lee , Surname, name
- Date: 2024-12
- Subjects: Book clubs (Discussion groups) -- South Africa , Literacy -- Study and teaching (Elementary) , Literacy -- Study and teaching (Middle school)
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68333 , vital:76976
- Description: School literacy practices have always favoured traditional, gender stereotypical portrayals of characters in books. These portrayals are not troublesome as it helps children build a sense of identity. However, these portrayals often fail to represent people in more diverse ways and thus does not reflect how societies have progressed. These narrow portrayals are also often limiting and do not take into consideration people’s personal interests which can lead to them being ostracised and marginalised. The People’s Republic of China is the context for this study where traditional, conservative views are upheld about ways of being and doing for males and females. This is a qualitative study within the interpretivist paradigm which recognised the individual perceptions of participants within their specific sociocultural context. By establishing a reading club as a Third Space for literacy engagement, this study sought to explore how grade 2 learners at a school in Beijing, China responded to traditional and diverse portrayals of characters in books. This study regarded the establishment of a reading club as an empowering practice as it allowed a safe space for the participants to freely share their deliberations about ways of being in the world. Coupled with critical literacy as a practice, participants took a critical stance in instances of gender bias and injustices and in doing so, allowed them to accentuate their morality. Findings of this study suggest that the Chinese participants had very flexible ideas about ways of being and doing in the world as long as these did not conflict with their understandings of the law. Participants also upheld that gender performances and gendered behaviour are open to all with impunity. The findings of this study also highlight the importance of providing diverse literature to children as this helps them to deal with, and examine, issues they might not ordinarily encounter in a safe way and in doing so, expand their worldviews and cultivate empathy. , Thesis (PhD) -- Faculty of Education, School of Primary Schooling, 2024
- Full Text:
- Date Issued: 2024-12
Exploring cultural context and masculine ideals: implications for male mental health help-seeking in South Africa
- Authors: Bux, Shezadia
- Date: 2024-12
- Subjects: Masculinity -- South Africa , Men -- Mental health , Help-seeking behavior -- Research
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69849 , vital:78040
- Description: The pervasive underdiagnosis and undertreatment of mental health issues among males, exacerbated by societal expectations of masculinity, represent a significant public health concern. This study addresses the critical gap in understanding how sociocultural constructs of masculinity influence mental health help-seeking behaviours among males in South Africa, a context marked by high rates of crime, violence, substance abuse, and male suicides. Adopting a qualitative research approach, this study conducted in-depth interviews with 12 participants, employing convenience and snowball sampling techniques to achieve data saturation. Thematic analysis was utilised to systematically identify and interpret patterns of meaning within the data, focusing on participants' understandings of mental health, the impact of sociocultural constructions of masculinity on their help-seeking behaviours, and the barriers they encounter. The findings illuminate the profound impact of sociocultural constructs of masculinity on male mental health help-seeking behaviours, revealing significant barriers rooted in societal stigma, traditional masculinity norms, and a lack of tailored mental health services. The study also introduces a conceptual model illustrating the influences on mental health acknowledgement and help-seeking behaviour among males in South Africa, underscored by a reflective analysis of exploring male emotional well-being. This study highlights the urgent need for culturally sensitive mental health care interventions that address the unique challenges faced by men in South African communities. By challenging societal norms and advocating for improved mental health awareness and services tailored to men, this research contributes to the broader discourse on gender, mental health, and social change, offering insights for researchers, policymakers, and practitioners aiming to enhance male mental health outcomes. , Thesis (MA) -- Faculty of Health Sciences, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Bux, Shezadia
- Date: 2024-12
- Subjects: Masculinity -- South Africa , Men -- Mental health , Help-seeking behavior -- Research
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69849 , vital:78040
- Description: The pervasive underdiagnosis and undertreatment of mental health issues among males, exacerbated by societal expectations of masculinity, represent a significant public health concern. This study addresses the critical gap in understanding how sociocultural constructs of masculinity influence mental health help-seeking behaviours among males in South Africa, a context marked by high rates of crime, violence, substance abuse, and male suicides. Adopting a qualitative research approach, this study conducted in-depth interviews with 12 participants, employing convenience and snowball sampling techniques to achieve data saturation. Thematic analysis was utilised to systematically identify and interpret patterns of meaning within the data, focusing on participants' understandings of mental health, the impact of sociocultural constructions of masculinity on their help-seeking behaviours, and the barriers they encounter. The findings illuminate the profound impact of sociocultural constructs of masculinity on male mental health help-seeking behaviours, revealing significant barriers rooted in societal stigma, traditional masculinity norms, and a lack of tailored mental health services. The study also introduces a conceptual model illustrating the influences on mental health acknowledgement and help-seeking behaviour among males in South Africa, underscored by a reflective analysis of exploring male emotional well-being. This study highlights the urgent need for culturally sensitive mental health care interventions that address the unique challenges faced by men in South African communities. By challenging societal norms and advocating for improved mental health awareness and services tailored to men, this research contributes to the broader discourse on gender, mental health, and social change, offering insights for researchers, policymakers, and practitioners aiming to enhance male mental health outcomes. , Thesis (MA) -- Faculty of Health Sciences, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Exploring resilience in undergraduate nursing students at a nursing education institution in the Eastern Cape, South Africa
- Authors: Blatti, Jenny
- Date: 2024-12
- Subjects: Nursing students -- South Africa -- Eastern Cape -- Psychology , Nursing -- Study and teaching -- South Africa , Nursing schools -- Faculty -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69805 , vital:78036
- Description: Undergraduate nursing students worldwide experience stress and anxiety due to the demands of nursing education, which include challenges related to academic workloads and the clinical environment. This, in turn, may impede programme completion and continuation in nursing careers. Resilience is recognised as an effective attribute for nursing students in adapting to stressors and has been found to have a beneficial impact on learning experiences, academic performance, and professional practice. Despite numerous research studies conducted on resilience in the health professions, there remains little empirical work that has explored undergraduate nursing students' understanding and experience of their resilience. The purpose of this study was thus to explore undergraduate nursing students’ perceptions of their resilience at a nursing education institution in the Eastern Cape, South Africa, and to compile recommendations for a resilience training programme in undergraduate nursing education. A qualitative, explorative, descriptive, and contextual research design was implemented, with the study underpinned by the Resilience Ecological Stress Model. Third and fourth-year nursing students were recruited by purposive sampling, following which data was collected online by means of eleven individual semi-structured interviews conducted and recorded on the Microsoft (MS) Teams platform. Data was analysed using Braun and Clarke’s six steps of reflexive thematic analysis, generating codes and themes. The following themes were identified: participants’ perceptions of their challenges while studying nursing, participants’ understanding and experience of resilience, and participants’ views on the unique requirements of the degree in nursing. Findings indicated that nursing students perceive resilience as a beneficial attribute in mitigating the stress and anxiety evoked by their diverse challenges. Recommendations for nursing education were formulated based on the theoretical framework constructs and the findings of the study. , Thesis (MCur) -- Faculty of Health Sciences, School of Clinical Care & Medicinal Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Blatti, Jenny
- Date: 2024-12
- Subjects: Nursing students -- South Africa -- Eastern Cape -- Psychology , Nursing -- Study and teaching -- South Africa , Nursing schools -- Faculty -- South Africa -- Eastern Cape
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69805 , vital:78036
- Description: Undergraduate nursing students worldwide experience stress and anxiety due to the demands of nursing education, which include challenges related to academic workloads and the clinical environment. This, in turn, may impede programme completion and continuation in nursing careers. Resilience is recognised as an effective attribute for nursing students in adapting to stressors and has been found to have a beneficial impact on learning experiences, academic performance, and professional practice. Despite numerous research studies conducted on resilience in the health professions, there remains little empirical work that has explored undergraduate nursing students' understanding and experience of their resilience. The purpose of this study was thus to explore undergraduate nursing students’ perceptions of their resilience at a nursing education institution in the Eastern Cape, South Africa, and to compile recommendations for a resilience training programme in undergraduate nursing education. A qualitative, explorative, descriptive, and contextual research design was implemented, with the study underpinned by the Resilience Ecological Stress Model. Third and fourth-year nursing students were recruited by purposive sampling, following which data was collected online by means of eleven individual semi-structured interviews conducted and recorded on the Microsoft (MS) Teams platform. Data was analysed using Braun and Clarke’s six steps of reflexive thematic analysis, generating codes and themes. The following themes were identified: participants’ perceptions of their challenges while studying nursing, participants’ understanding and experience of resilience, and participants’ views on the unique requirements of the degree in nursing. Findings indicated that nursing students perceive resilience as a beneficial attribute in mitigating the stress and anxiety evoked by their diverse challenges. Recommendations for nursing education were formulated based on the theoretical framework constructs and the findings of the study. , Thesis (MCur) -- Faculty of Health Sciences, School of Clinical Care & Medicinal Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Exploring the nature of the parent-child relationship and well- being of adolescents in families with a current history of maternal mental illness in a semi-urban area in East London, Eastern Cape
- Authors: Phakane, Siphokazi
- Date: 2024-12
- Subjects: Parent and child , Adolescent psychology , Mental illness
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69838 , vital:78039
- Description: Parent mental illness can detrimentally impact family functioning, thereby leading to increased conflicts, reduced adaptability, limited cohesion, and disorganised everyday planning (Smith, 2018). However, the specific effects of maternal mental illness on the relationship between mothers and adolescents, as well as on adolescent social and psychological development, remain unclear (Jones & Brown, 2020). This study aimed to explore and describe the nature of the parent-child relationship and the well-being of adolescents in families with a current history of maternal mental illness. Drawing from Bowlby's Ethological Theory of Attachment (1969) and from Ainsworth’s Attachment Theory (1970), qualitative research methods were employed to delve into these dynamics. The participants encompassed mothers aged between 30 to 60 with a current history of mental illness and adolescents aged between 15 to 18 residing with a mother with a current history of mental illness, and who is in remission. The study was conducted in a semi-urban area in East London, which is characterised by high unemployment rates, low education levels, and social stressors impacting mental health and family dynamics (Clark et al., 2019). Data collection involved face-to-face interviews, as well as utilising non-probability purposive and snowball sampling techniques. Braun and Clarke's (2006) framework was utilised for data interpretation, thus ensuring the adherence to the research ethics and to the trustworthiness standards as outlined by Lincoln and Guba (1985). The findings revealed both challenges and strengths in these families. The adolescents expressed concerns about the lack of parental support, coerced autonomy, and communication barriers. However, they also reported positive experiences of companionship and nurturing from their mothers. Emotional regulation difficulties and socio-economic challenges were prevalent, thus highlighting the need for tailored targeted support interventions to address the complex issues that are faced by the adolescents in the families which are affected by maternal mental illness. Overall, this research contributes to a deeper understanding of the nuanced , Thesis (MA) -- Faculty of Health Sciences, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Phakane, Siphokazi
- Date: 2024-12
- Subjects: Parent and child , Adolescent psychology , Mental illness
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69838 , vital:78039
- Description: Parent mental illness can detrimentally impact family functioning, thereby leading to increased conflicts, reduced adaptability, limited cohesion, and disorganised everyday planning (Smith, 2018). However, the specific effects of maternal mental illness on the relationship between mothers and adolescents, as well as on adolescent social and psychological development, remain unclear (Jones & Brown, 2020). This study aimed to explore and describe the nature of the parent-child relationship and the well-being of adolescents in families with a current history of maternal mental illness. Drawing from Bowlby's Ethological Theory of Attachment (1969) and from Ainsworth’s Attachment Theory (1970), qualitative research methods were employed to delve into these dynamics. The participants encompassed mothers aged between 30 to 60 with a current history of mental illness and adolescents aged between 15 to 18 residing with a mother with a current history of mental illness, and who is in remission. The study was conducted in a semi-urban area in East London, which is characterised by high unemployment rates, low education levels, and social stressors impacting mental health and family dynamics (Clark et al., 2019). Data collection involved face-to-face interviews, as well as utilising non-probability purposive and snowball sampling techniques. Braun and Clarke's (2006) framework was utilised for data interpretation, thus ensuring the adherence to the research ethics and to the trustworthiness standards as outlined by Lincoln and Guba (1985). The findings revealed both challenges and strengths in these families. The adolescents expressed concerns about the lack of parental support, coerced autonomy, and communication barriers. However, they also reported positive experiences of companionship and nurturing from their mothers. Emotional regulation difficulties and socio-economic challenges were prevalent, thus highlighting the need for tailored targeted support interventions to address the complex issues that are faced by the adolescents in the families which are affected by maternal mental illness. Overall, this research contributes to a deeper understanding of the nuanced , Thesis (MA) -- Faculty of Health Sciences, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Extending psychological praxis within South Africa: exploring healers’ perceptions of treatment plurality
- Authors: Yew-Siong, Lauren
- Date: 2024-12
- Subjects: Traditional medicine -- South Africa , Psychology -- Africa , Clinical health psychology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69771 , vital:78032
- Description: The prevailing psychological praxis in South Africa predominantly follows western paradigms for defining, classifying, and diagnosing health and illness; falling short in encompassing the diverse mental healthcare reality. Scarce resources, inadequate infrastructure, and the interplay of religio-cultural beliefs intersect, shaping how psychological disturbances are perceived and how treatment is sought- especially for patients who do not ascribe to one treatment modality, or one paradigm. Therefore, this study explored ideas and notions surrounding treatment plurality held by healers (that being psychologists, psychiatrists, and traditional healers), within the South African context. The research utilised a qualitative exploratory-descriptive research methodology with a phenomenological research design. The researcher then employed purposive and snowball sampling to recruit participants. Thereafter, the researcher conducted online semi-structured interviews, and applied Braun and Clarke's (2006) thematic analysis to analyse the data. The following themes were then unpacked: 1) Healers’ perceptions of treatment plurality; 2) The need for collaboration between various disciplines; 3) Education as a key factor in pluralism; 4) Healer ethics and malpractice; 5) The lack of governmental funding and resources. The results suggest the need for a pluralistic mental healthcare approach in South Africa, bridging western and traditional practices. Yet, challenges stemming from inadequate governmental funding, resources, policies, and ethical guidelines hinder its development and implementation. Therefore, it would take more than one set of guidelines to implement pluralistic treatment within South African mental healthcare. For this purpose, the researcher decided to create a blueprint for various developments that is needed to make a pluralistic approach a reality in South Africa. These findings encouraged the researcher to develop: 1) Guidelines for the Provision of Collaborative Care in Mental Healthcare Services; 2) Guidelines for South African governmental policy that foster pluralism and collaborative care in the mental healthcare system; 3) A pluralistic medical aid scheme; 4) A module blueprint that could potentially be included in a professional master’s programme, as well as the inclusion of a theory the researcher has developed, named the Pluralism-oriented Mental Healthcare Theory. , Thesis (PhD) -- Faculty of Health Sciences, School of Behavioural & Lifestyle Sciences, 2023
- Full Text:
- Date Issued: 2024-12
- Authors: Yew-Siong, Lauren
- Date: 2024-12
- Subjects: Traditional medicine -- South Africa , Psychology -- Africa , Clinical health psychology
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/69771 , vital:78032
- Description: The prevailing psychological praxis in South Africa predominantly follows western paradigms for defining, classifying, and diagnosing health and illness; falling short in encompassing the diverse mental healthcare reality. Scarce resources, inadequate infrastructure, and the interplay of religio-cultural beliefs intersect, shaping how psychological disturbances are perceived and how treatment is sought- especially for patients who do not ascribe to one treatment modality, or one paradigm. Therefore, this study explored ideas and notions surrounding treatment plurality held by healers (that being psychologists, psychiatrists, and traditional healers), within the South African context. The research utilised a qualitative exploratory-descriptive research methodology with a phenomenological research design. The researcher then employed purposive and snowball sampling to recruit participants. Thereafter, the researcher conducted online semi-structured interviews, and applied Braun and Clarke's (2006) thematic analysis to analyse the data. The following themes were then unpacked: 1) Healers’ perceptions of treatment plurality; 2) The need for collaboration between various disciplines; 3) Education as a key factor in pluralism; 4) Healer ethics and malpractice; 5) The lack of governmental funding and resources. The results suggest the need for a pluralistic mental healthcare approach in South Africa, bridging western and traditional practices. Yet, challenges stemming from inadequate governmental funding, resources, policies, and ethical guidelines hinder its development and implementation. Therefore, it would take more than one set of guidelines to implement pluralistic treatment within South African mental healthcare. For this purpose, the researcher decided to create a blueprint for various developments that is needed to make a pluralistic approach a reality in South Africa. These findings encouraged the researcher to develop: 1) Guidelines for the Provision of Collaborative Care in Mental Healthcare Services; 2) Guidelines for South African governmental policy that foster pluralism and collaborative care in the mental healthcare system; 3) A pluralistic medical aid scheme; 4) A module blueprint that could potentially be included in a professional master’s programme, as well as the inclusion of a theory the researcher has developed, named the Pluralism-oriented Mental Healthcare Theory. , Thesis (PhD) -- Faculty of Health Sciences, School of Behavioural & Lifestyle Sciences, 2023
- Full Text:
- Date Issued: 2024-12
Formulation of Fish Feed for Aquaculture using Olive Pomace Extract as an Antioxidant
- Authors: Koza, Nondumiso Norma
- Date: 2024-12
- Subjects: Fishes -- Feeding and feeds , Fishes -- Ecology , Sustainable aquaculture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69318 , vital:77205
- Description: Olive pomace is a significant by-product of the olive oil extraction process and is an environmental issue in olive-producing countries. This project aimed to add extracts from olive pomace as an antioxidant to a fish feed formulation without compromising growth performance and meat quality, thereby contributing to the aquaculture industry. To produce the olive pomace extracts, Coratina cultivar olives were collected from a farm near Oudtshoorn, and the fresh pomace was immediately frozen at -22oC for preservation. The extracts were obtained using a large-scale extraction method using a solvent blend of n-heptane, ethanol, and water. A pressure filtration and centrifuge method were then applied to separate any residue from the extracts. An HPLC method was developed to characterise the extracts' content, identifying various bioactive compounds such as squalene, α-tocopherol, and water-soluble polyphenols like oleuropein, hydroxytyrosol, and tyrosol. In a fish feeding trial it was concluded that the fish fed with the feed without olive pomace gained more weight than those fed the feed with the added pomace extract. Overall, the results indicate that fish sustained on the feed without the olive pomace extract ate more food, consuming more energy to support weight gain but that this did not necessarily translate to an improved feed conversion ratio. The morphometric variables suggest that fish used in the trial remained healthy, implying that there may be a taste or palatability difference between feeds that could explain why less of the feed with olive pomace extract was eaten. Overall, the observed feed conversion ratio values were somewhat lower than the expected values for tilapia (FCR: 1.5-2.0). The peroxide value of fish feed with an addition of 0.3% olive pomace extract was lower than that of the feed without olive pomace extract after 12 weeks of stability testing at room temperature. The results showed a value of 1.48 MeqO2/kg for the feed containing olive pomace extract compared to the peroxide value for the fish feed without olive pomace extract, which was 2.75 MeqO2/kg. This indicates that the nutritional content of the feed was preserved. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Koza, Nondumiso Norma
- Date: 2024-12
- Subjects: Fishes -- Feeding and feeds , Fishes -- Ecology , Sustainable aquaculture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69318 , vital:77205
- Description: Olive pomace is a significant by-product of the olive oil extraction process and is an environmental issue in olive-producing countries. This project aimed to add extracts from olive pomace as an antioxidant to a fish feed formulation without compromising growth performance and meat quality, thereby contributing to the aquaculture industry. To produce the olive pomace extracts, Coratina cultivar olives were collected from a farm near Oudtshoorn, and the fresh pomace was immediately frozen at -22oC for preservation. The extracts were obtained using a large-scale extraction method using a solvent blend of n-heptane, ethanol, and water. A pressure filtration and centrifuge method were then applied to separate any residue from the extracts. An HPLC method was developed to characterise the extracts' content, identifying various bioactive compounds such as squalene, α-tocopherol, and water-soluble polyphenols like oleuropein, hydroxytyrosol, and tyrosol. In a fish feeding trial it was concluded that the fish fed with the feed without olive pomace gained more weight than those fed the feed with the added pomace extract. Overall, the results indicate that fish sustained on the feed without the olive pomace extract ate more food, consuming more energy to support weight gain but that this did not necessarily translate to an improved feed conversion ratio. The morphometric variables suggest that fish used in the trial remained healthy, implying that there may be a taste or palatability difference between feeds that could explain why less of the feed with olive pomace extract was eaten. Overall, the observed feed conversion ratio values were somewhat lower than the expected values for tilapia (FCR: 1.5-2.0). The peroxide value of fish feed with an addition of 0.3% olive pomace extract was lower than that of the feed without olive pomace extract after 12 weeks of stability testing at room temperature. The results showed a value of 1.48 MeqO2/kg for the feed containing olive pomace extract compared to the peroxide value for the fish feed without olive pomace extract, which was 2.75 MeqO2/kg. This indicates that the nutritional content of the feed was preserved. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Graphene@microalgae-based nanohybrid structures as adsorbents for removal of Cr(VI) ions in aqueous solutions
- Authors: Mulovhedzi, Rolivhuwa
- Date: 2024-12
- Subjects: Nanoscience , Nanotechnology , Nonaqueous solvents
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69404 , vital:77252
- Description: iv ABSTRACT The efficient removal of heavy metals using carbon-based nanoadsorbents poses a substantial challenge in the domain of water purification. Graphene-based materials have been extensively utilised in the treatment of water and wastewater due to their tremendous surface areas, porosity, turntable nature to different functional groups, and photo-catalytic properties. In this project, graphene oxide (GO) was synthesised via the modified Hummers method. A similar method was used to produce nitrogen-doped graphene oxide (NGO), with urea as the nitrogen precursor. Utilising biomass materials to dope graphene-based nanocomposites can effectively enhance their application in water treatment. In this work, graphene oxide-microalgae (GO@Algae) and N-doped graphene oxide-microalgae (NGO@Algae) nanocomposites were synthesised by combining GO or NGO with green Scenedesmus microalgae. This was done through a solution self-assembly mixing method using ultrasonication. The resulting nanocomposites were used to remove Cr(VI) from water solutions. The influence of microalgae content deposited on GO and NGO nanosheets at different weight ratios (1:1, 3:1, and 1:3) on the chemical, structural, morphological, and thermal characteristics of nanoadsorbents was evaluated using various techniques such as Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The flat nanosheet-like morphology of GO@Algae and NGO@Algae nanostructured materials was observed through SEM, confirming microalgae's incorporation within the GO and NGO matrices. The thermal stability and surface area properties of GO and NGO nanocomposite materials decreased with the incorporation of microalgae content. The incorporation of microalgae into GO nanosheets showed enhancements in chemical and structural properties due to the presence of the strong covalent interaction (oxygen and nitrogen-containing groups) between the interfaces of nanocomposites. XPS and FT-IR analyses revealed the existence of amides, carboxylic acids, and phosphates, which exhibited positive charges below the pH 2.03 point-of-zero charge. The second phase of the study involved assessing the adsorption capabilities of the GO, NGO nanosheets, and GO@Algae and NGO@Algae nanocomposites in removing Cr(VI)from the water solution. Adsorption parameters such as the effect of solution pH, contact time, adsorbent dosage and metal ion concentrations were evaluated for Cr(VI) removal. When comparing GO, NGO, GO@Algae, and NGO@Algae, it was found that GO@Algae and NGO@Algae exhibited superior adsorption performance due to the available functional groups and well-developed pores. Additionally, a mixed ratio of GO or NGO and algae at a ratio of 1:3 was found to be the most suitable for GO@Algae and NGO@Algae. The adsorption efficiency of nanostructured materials for Cr(VI) is significantly influenced by their surface charge, porosity and specific surface area. The results revealed that the adsorption capabilities of GO@Algae (1:3) and NGO@Algae (1:3) were 2.24 and 2.01 times higher than GO and NGO which were 1.64 and 1.89, respectively, at a solution of pH 2 where HCrO4− species are predominant compared to a solution of pH 5 which predominate a mix of Cr2O72− and CrO42- species. The enhanced performance of the GO@Algae and NGO@Algae nanocomposites is attributed due to their increased surface functionalities and porosity. The adsorption of Cr(VI) ions by the GO/NGO@Algae nanocomposites declined with increasing initial concentration of Cr(VI) species in the water medium. The adsorption kinetics data for GO, NGO, GO@Algae (1:3), and NGO@Algae (1:3) exhibited a good fit with the pseudo-second-order model (R2 > 0.995) suggesting that chemisorption governed the adsorption process. Similarly, the isotherm adsorption findings showed a good fit with the Freundlich model (R2 > 0.961). The findings indicated that the adsorption mechanism process was characterised by monolayer adsorption onto a heterogeneous adsorbent surface. Furthermore, the GO@Algae (1:3) was found to have the maximum adsorption capacity of 10.85 mg/g surpassing the capacities of both unmodified and NGO@Algae counterparts. The application of GO@Algae and NGO@Algae has the potential to promote the green reuse of graphene-based nanomaterials. In summary, GO@Algae and NGO@Algae show great potential as eco-friendly adsorbents for the feasible treatment of heavy metal-contaminated water. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Mulovhedzi, Rolivhuwa
- Date: 2024-12
- Subjects: Nanoscience , Nanotechnology , Nonaqueous solvents
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69404 , vital:77252
- Description: iv ABSTRACT The efficient removal of heavy metals using carbon-based nanoadsorbents poses a substantial challenge in the domain of water purification. Graphene-based materials have been extensively utilised in the treatment of water and wastewater due to their tremendous surface areas, porosity, turntable nature to different functional groups, and photo-catalytic properties. In this project, graphene oxide (GO) was synthesised via the modified Hummers method. A similar method was used to produce nitrogen-doped graphene oxide (NGO), with urea as the nitrogen precursor. Utilising biomass materials to dope graphene-based nanocomposites can effectively enhance their application in water treatment. In this work, graphene oxide-microalgae (GO@Algae) and N-doped graphene oxide-microalgae (NGO@Algae) nanocomposites were synthesised by combining GO or NGO with green Scenedesmus microalgae. This was done through a solution self-assembly mixing method using ultrasonication. The resulting nanocomposites were used to remove Cr(VI) from water solutions. The influence of microalgae content deposited on GO and NGO nanosheets at different weight ratios (1:1, 3:1, and 1:3) on the chemical, structural, morphological, and thermal characteristics of nanoadsorbents was evaluated using various techniques such as Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The flat nanosheet-like morphology of GO@Algae and NGO@Algae nanostructured materials was observed through SEM, confirming microalgae's incorporation within the GO and NGO matrices. The thermal stability and surface area properties of GO and NGO nanocomposite materials decreased with the incorporation of microalgae content. The incorporation of microalgae into GO nanosheets showed enhancements in chemical and structural properties due to the presence of the strong covalent interaction (oxygen and nitrogen-containing groups) between the interfaces of nanocomposites. XPS and FT-IR analyses revealed the existence of amides, carboxylic acids, and phosphates, which exhibited positive charges below the pH 2.03 point-of-zero charge. The second phase of the study involved assessing the adsorption capabilities of the GO, NGO nanosheets, and GO@Algae and NGO@Algae nanocomposites in removing Cr(VI)from the water solution. Adsorption parameters such as the effect of solution pH, contact time, adsorbent dosage and metal ion concentrations were evaluated for Cr(VI) removal. When comparing GO, NGO, GO@Algae, and NGO@Algae, it was found that GO@Algae and NGO@Algae exhibited superior adsorption performance due to the available functional groups and well-developed pores. Additionally, a mixed ratio of GO or NGO and algae at a ratio of 1:3 was found to be the most suitable for GO@Algae and NGO@Algae. The adsorption efficiency of nanostructured materials for Cr(VI) is significantly influenced by their surface charge, porosity and specific surface area. The results revealed that the adsorption capabilities of GO@Algae (1:3) and NGO@Algae (1:3) were 2.24 and 2.01 times higher than GO and NGO which were 1.64 and 1.89, respectively, at a solution of pH 2 where HCrO4− species are predominant compared to a solution of pH 5 which predominate a mix of Cr2O72− and CrO42- species. The enhanced performance of the GO@Algae and NGO@Algae nanocomposites is attributed due to their increased surface functionalities and porosity. The adsorption of Cr(VI) ions by the GO/NGO@Algae nanocomposites declined with increasing initial concentration of Cr(VI) species in the water medium. The adsorption kinetics data for GO, NGO, GO@Algae (1:3), and NGO@Algae (1:3) exhibited a good fit with the pseudo-second-order model (R2 > 0.995) suggesting that chemisorption governed the adsorption process. Similarly, the isotherm adsorption findings showed a good fit with the Freundlich model (R2 > 0.961). The findings indicated that the adsorption mechanism process was characterised by monolayer adsorption onto a heterogeneous adsorbent surface. Furthermore, the GO@Algae (1:3) was found to have the maximum adsorption capacity of 10.85 mg/g surpassing the capacities of both unmodified and NGO@Algae counterparts. The application of GO@Algae and NGO@Algae has the potential to promote the green reuse of graphene-based nanomaterials. In summary, GO@Algae and NGO@Algae show great potential as eco-friendly adsorbents for the feasible treatment of heavy metal-contaminated water. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Ground- and marine water inputs into supratidal microbialite systems along the Nelson Mandela Bay coastline
- Authors: O’Connell, Tristin Wade
- Date: 2024-12
- Subjects: Groundwater -- South Africa -- Nelson Mandela Bay , Earth sciences , Geology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69415 , vital:77253
- Description: Extant supratidal microbialite systems are especially numerous and well-developed along the rocky coastline of Nelson Mandela Bay (NMB), South Africa. Precipitating in a hydrological environment formed by the input of constant, fresh groundwater discharge and periodic marine water intrusion these systems form part of the longest uninterrupted geological record of life on Earth (~3.4 billion years ago). Microbialites are layered organosedimentary deposits which potentially provide a window into historical environmental conditions. This study focusses on the fresh groundwater and saline marine water inputs of these microbialite pools, and the corresponding microbialite accretion rates. Severe regional drought in the NMB area resulted in rapid anthropogenic groundwater abstraction of the coastal aquifers on which the microbialite systems rely for groundwater inflow. This study provides insight into the current state of the coastal aquifers of NMB through the quantification of groundwater discharge via microbialite systems in terms of volume and flow rate. This is paired with in situ hourly microbialite pool water temperature and conductivity data to determine the effect of marine intrusion and the role of tidal flushing in these pools. A spatial assessment of groundwater discharge conducted using quantitative and semi-quantitative measurement techniques indicated that the total discharge of the study area is ~45.8 L/s or 3.8 ML/d. Over 1,500 freshwater seeps were identified, of which 78% showed microbialite deposits. Topography of the coast indicated that this might influence the flowrate. Calcareous sediment of sandy beaches within the study area supported lower discharge, while rocky shores with lithified rock had higher discharge. Seasonal differences in the volume discharged were evident, with winter having higher flowrates. Flow paths and discharge rates are affected by inland lithological differences and indicate variability linked to rainfall events that show lag effects depending on aquifer origins. This study is the first spatial analysis of the volume of groundwater discharging through microbialite-fed seeps. Marine intrusion and the corresponding pool flushing dynamics identified three types of microbailite systems: groundwater-dominant, dynamic input, and fast-reacting sites. A novel measurement technique for microbialite accretion determined accretion rates for systems under varying pool conditions. Although the average accretion rates of the Nelson Mandela Bay microbialites were in the order of erosion of 0.35 mm per year, there was significant variability in these measurements likely linked to differential localised vulnerability to storm events or responses to groundwater ix flow variability. It remains to be determined whether these factors are definitive risks to the sensitive supratidal microbialite systems. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: O’Connell, Tristin Wade
- Date: 2024-12
- Subjects: Groundwater -- South Africa -- Nelson Mandela Bay , Earth sciences , Geology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69415 , vital:77253
- Description: Extant supratidal microbialite systems are especially numerous and well-developed along the rocky coastline of Nelson Mandela Bay (NMB), South Africa. Precipitating in a hydrological environment formed by the input of constant, fresh groundwater discharge and periodic marine water intrusion these systems form part of the longest uninterrupted geological record of life on Earth (~3.4 billion years ago). Microbialites are layered organosedimentary deposits which potentially provide a window into historical environmental conditions. This study focusses on the fresh groundwater and saline marine water inputs of these microbialite pools, and the corresponding microbialite accretion rates. Severe regional drought in the NMB area resulted in rapid anthropogenic groundwater abstraction of the coastal aquifers on which the microbialite systems rely for groundwater inflow. This study provides insight into the current state of the coastal aquifers of NMB through the quantification of groundwater discharge via microbialite systems in terms of volume and flow rate. This is paired with in situ hourly microbialite pool water temperature and conductivity data to determine the effect of marine intrusion and the role of tidal flushing in these pools. A spatial assessment of groundwater discharge conducted using quantitative and semi-quantitative measurement techniques indicated that the total discharge of the study area is ~45.8 L/s or 3.8 ML/d. Over 1,500 freshwater seeps were identified, of which 78% showed microbialite deposits. Topography of the coast indicated that this might influence the flowrate. Calcareous sediment of sandy beaches within the study area supported lower discharge, while rocky shores with lithified rock had higher discharge. Seasonal differences in the volume discharged were evident, with winter having higher flowrates. Flow paths and discharge rates are affected by inland lithological differences and indicate variability linked to rainfall events that show lag effects depending on aquifer origins. This study is the first spatial analysis of the volume of groundwater discharging through microbialite-fed seeps. Marine intrusion and the corresponding pool flushing dynamics identified three types of microbailite systems: groundwater-dominant, dynamic input, and fast-reacting sites. A novel measurement technique for microbialite accretion determined accretion rates for systems under varying pool conditions. Although the average accretion rates of the Nelson Mandela Bay microbialites were in the order of erosion of 0.35 mm per year, there was significant variability in these measurements likely linked to differential localised vulnerability to storm events or responses to groundwater ix flow variability. It remains to be determined whether these factors are definitive risks to the sensitive supratidal microbialite systems. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Gymnopilus junonius and Rhodofomitopsis lilacinogilva: In vitro evaluation of antimycobacterial activity, safety assessment and isolation of active compounds
- Authors: Didloff, Jenske
- Date: 2024-12
- Subjects: Antibacterial agents , Plants, Useful -- South Africa , Medicinal plants -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68840 , vital:77122
- Description: Tuberculosis remains a significant public health challenge due to the complexity and compliance issues of its treatment, the prevalence of latent infections, the high rate of HIV co-infection, and the spread of drug-resistant strains. This highlights the need to search for new antimycobacterial drugs. Natural products have historically been used as sources for the discovery of pharmaceuticals. Although medicinal macrofungi have been exploited in traditional folk medicines for the treatment of various diseases, research into their antimycobacterial activity remains limited.The aim of this study was to isolate, identify, and characterise the antimycobacterial compound(s) present in ethanol fruiting body extracts of Gymnopilus junonius (Fr.) P.D. Orton (Hymenogastraceae) and Rhodofomitopsis lilacinogilva (Berk.) B.K. Cui, M.L. Han, & Y.C. Dai (Fomitopsidaceae), as well as to investigate their mechanism of action and potential toxicity using in vitro and in vivo screening methods.Bioassay-guided fractionation was conducted using column chromatography and preparative thin-layer chromatography to isolate the active antimycobacterial fraction/compound from ethanol extracts of G. junonius and R. lilacinogilva. Antimycobacterial activity against M. tuberculosis H37Rv was screened using a resazurin microplate assay (REMA). The chemical structure was elucidated employing 1D-(1H NMR) and 2D NMR spectroscopy (HSQC, HMBC) techniques, along with High- Performance Liquid Chromatography High-Resolution Electron Spray Ionisation Mass Spectrometry (HPLC-HRESI-MS). Transmission electron microscopy (TEM) was utilised to observe the ultrastructural changes in M. tuberculosis induced by the active fraction/compound. Toxicity assessment was performed on African green monkeykidney (Vero) and human hepatoma (C3A) cell lines using various staining techniques to observe the potential risk for hepatotoxicity (CellRox orange, TMRE, and MTG staining) and genotoxicity (NucRed staining). In vivo toxicity of extracts was evaluated using a zebrafish embryo/larvae model to observe developmental and teratogenic effects.The bioassay-guided fractionation of G. junonius and R. lilacinogilva extracts yielded an active compound and a fraction displaying inhibitory activity against M. tuberculosis, with MIC values of 31.25 μg/mL and 250 μg/mL, respectively. Gymnopilene was identified as the main active compound isolated from G. junonius, while fraction 8 from R. lilacinogilva contained a predominant constituent resembling a pachymic acid derivative. Transmission electron microscopy revealed ultrastructural damage to M. tuberculosis cells upon treatment with gymnopilene and fraction 8, which was observed as the disruption and disintegration of the cell wall. In vitro toxicity assessment indicated a reduction in the cell density in both Vero and C3A cell lines following exposure to the fractions/gymnopilene. Although there were no significant alterations in the production of reactive oxygen species, changes in mitochondrial dynamics were observed. Genotoxic assessment showed no significant changes. In vivo toxicity assessment showed no significant effects for G. junonius against the zebrafish embryos/larvae, whereas R. lilacinogilva remained toxic and induced developmental abnormalities over a 72-hour time period.The findings of this study highlight the potential of macrofungi as a valuable source of bioactive compounds, confirming the significance of natural products in drug discovery. Notably, this research represents the first to demonstrate that the predominant compound, gymnopilene, isolated from G. junonius exhibits inhibitory activity against M. tuberculosis, contributing to the novelty of the study. Furthermore, the study expands our understanding of the antimycobacterial properties of the selected macrofungal species, G. junonius and R. lilacinogilva, by demonstrating the ultrastructural damage to M. tuberculosis cell wall induced by treatment. However, it is important to recognise the potential toxicity identified through in vitro and/or in vivo screening assays. The observed toxicity may hamper their suitability formdrug development. Future investigations could explore the inclusion of additional in vitro based models, perhaps more complex and physiologically relevant models alongside the in vivo screening model to assess the therapeutic potential of isolated fractions/compounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Didloff, Jenske
- Date: 2024-12
- Subjects: Antibacterial agents , Plants, Useful -- South Africa , Medicinal plants -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/68840 , vital:77122
- Description: Tuberculosis remains a significant public health challenge due to the complexity and compliance issues of its treatment, the prevalence of latent infections, the high rate of HIV co-infection, and the spread of drug-resistant strains. This highlights the need to search for new antimycobacterial drugs. Natural products have historically been used as sources for the discovery of pharmaceuticals. Although medicinal macrofungi have been exploited in traditional folk medicines for the treatment of various diseases, research into their antimycobacterial activity remains limited.The aim of this study was to isolate, identify, and characterise the antimycobacterial compound(s) present in ethanol fruiting body extracts of Gymnopilus junonius (Fr.) P.D. Orton (Hymenogastraceae) and Rhodofomitopsis lilacinogilva (Berk.) B.K. Cui, M.L. Han, & Y.C. Dai (Fomitopsidaceae), as well as to investigate their mechanism of action and potential toxicity using in vitro and in vivo screening methods.Bioassay-guided fractionation was conducted using column chromatography and preparative thin-layer chromatography to isolate the active antimycobacterial fraction/compound from ethanol extracts of G. junonius and R. lilacinogilva. Antimycobacterial activity against M. tuberculosis H37Rv was screened using a resazurin microplate assay (REMA). The chemical structure was elucidated employing 1D-(1H NMR) and 2D NMR spectroscopy (HSQC, HMBC) techniques, along with High- Performance Liquid Chromatography High-Resolution Electron Spray Ionisation Mass Spectrometry (HPLC-HRESI-MS). Transmission electron microscopy (TEM) was utilised to observe the ultrastructural changes in M. tuberculosis induced by the active fraction/compound. Toxicity assessment was performed on African green monkeykidney (Vero) and human hepatoma (C3A) cell lines using various staining techniques to observe the potential risk for hepatotoxicity (CellRox orange, TMRE, and MTG staining) and genotoxicity (NucRed staining). In vivo toxicity of extracts was evaluated using a zebrafish embryo/larvae model to observe developmental and teratogenic effects.The bioassay-guided fractionation of G. junonius and R. lilacinogilva extracts yielded an active compound and a fraction displaying inhibitory activity against M. tuberculosis, with MIC values of 31.25 μg/mL and 250 μg/mL, respectively. Gymnopilene was identified as the main active compound isolated from G. junonius, while fraction 8 from R. lilacinogilva contained a predominant constituent resembling a pachymic acid derivative. Transmission electron microscopy revealed ultrastructural damage to M. tuberculosis cells upon treatment with gymnopilene and fraction 8, which was observed as the disruption and disintegration of the cell wall. In vitro toxicity assessment indicated a reduction in the cell density in both Vero and C3A cell lines following exposure to the fractions/gymnopilene. Although there were no significant alterations in the production of reactive oxygen species, changes in mitochondrial dynamics were observed. Genotoxic assessment showed no significant changes. In vivo toxicity assessment showed no significant effects for G. junonius against the zebrafish embryos/larvae, whereas R. lilacinogilva remained toxic and induced developmental abnormalities over a 72-hour time period.The findings of this study highlight the potential of macrofungi as a valuable source of bioactive compounds, confirming the significance of natural products in drug discovery. Notably, this research represents the first to demonstrate that the predominant compound, gymnopilene, isolated from G. junonius exhibits inhibitory activity against M. tuberculosis, contributing to the novelty of the study. Furthermore, the study expands our understanding of the antimycobacterial properties of the selected macrofungal species, G. junonius and R. lilacinogilva, by demonstrating the ultrastructural damage to M. tuberculosis cell wall induced by treatment. However, it is important to recognise the potential toxicity identified through in vitro and/or in vivo screening assays. The observed toxicity may hamper their suitability formdrug development. Future investigations could explore the inclusion of additional in vitro based models, perhaps more complex and physiologically relevant models alongside the in vivo screening model to assess the therapeutic potential of isolated fractions/compounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Impact of an educational intervention on hygiene knowledge and practices among municipal waste and sanitation workers in Nelson Mandela Bay, South Africa
- Authors: Ntunja, Alive
- Date: 2024-12
- Subjects: Public health , Hygiene , Environmental health
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69738 , vital:78015
- Description: Municipal waste and sanitation workers (street sweepers, latrine cleaners, and waste transporters) play a crucial role in maintaining public health by providing a safe and clean environment. They accomplish this by performing tasks such as sweeping streets, collecting domestic waste regularly, pit latrine cleaning, cleaning public toilets, and operating waste collection trucks. Nonetheless, they play an important role in mitigating health-related challenges by ensuring a clean and healthy environment through correct waste collection and disposal practices. Therefore, safe waste collection is a critical undertaking that safeguards the health and living conditions of individuals worldwide. However, their hygiene-related knowledge and practices remain low due to a lack of educational intervention programmes on hygiene. Therefore, the study investigated the impact of an educational intervention on hygiene knowledge and practices amongst municipal waste and sanitation workers in Nelson Mandela Bay Municipality (NMBM). The study used a quasi-experimental study, one group, (pre- and post-test) design, using an educational intervention. A total of 201 municipal waste and sanitation workers were conveniently sampled in the study from all five municipal waste depots and six wastewater treatment plants in the NMBM. A self-administered, structured, hard-copy questionnaire was used to collect the participants’ demographic data and a pre-intervention assessment on hygiene-related knowledge and practices. An educational intervention based on existing literature and national environmental cleaning guidelines and policies was implemented, and after a minimum gap of two months following the intervention, participants were asked to complete the postintervention questionnaire. The collected data was captured in a QuestionPro survey platform and analysed in Microsoft Office 365 (2019 version) and R software (version 4.4.1). The knowledge and practice items were further evaluated for internal reliability using the Cronbach’s alpha technique. Inferential statistics were used to analyse and describe the data, including tests such as Pearson’s correlations, student t-tests, analysis of variance (ANOVA) and multivariable linear regression analysis. A total of 201 participants, comprising 148 (73.6%) males and 53 (26.4%) females, participated in the study. Of the 201 participants, 95 (47.3%) indicated that 2 they had never heard of hygiene-related diseases. The study participants had poor knowledge and practices regarding hygiene prior to the educational intervention. Based on the paired samples t-test, there was a significant difference post-intervention phase in the mean scores for hygiene knowledge of 4.0 (±4.8), p<0.001 as well as hygiene practice scores of 4.3 (±3.4), p<0.001. Output obtained from the multivariable linear regression analysis revealed that participants working in Depot (A) (β=-2.82, p=0.005) were less knowledgeable about hygiene compared to those in Depot (B) in the pre-intervention phase. Participants who have not heard of hygiene-related diseases (β=-3.05, p<0.001) were significantly less knowledgeable about hygiene than their counterparts who have previously heard about hygiene-related diseases. Participants older than 51 years of age had poorer knowledge (b=-0.09, p=0.919) regarding hygiene when compared to the participants who were 18-30 years old. Furthermore, only female participants (b=1.44, p=0.022) and the Coloured ethnic group (b=1.44, p=0.050) had good hygiene practices when handling waste, compared to male participants and those of Black African ethnicity. The study's findings highlight the significant positive impact of an implemented educational intervention programme amongst municipal waste and sanitation workers on improving their knowledge of hygiene-related diseases and hygiene practices when discharging their duties. However, predictor factors such as working environment, educational training background, age, and race significantly influenced the impact of the implemented educational programme. The ongoing implementation of similar initiatives is highly recommended amongst municipal waste and sanitation workers, thus preventing hygiene-related infections amongst the studied population and fostering a healthier environment. , Thesis (MSc) -- Faculty of Science, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Ntunja, Alive
- Date: 2024-12
- Subjects: Public health , Hygiene , Environmental health
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69738 , vital:78015
- Description: Municipal waste and sanitation workers (street sweepers, latrine cleaners, and waste transporters) play a crucial role in maintaining public health by providing a safe and clean environment. They accomplish this by performing tasks such as sweeping streets, collecting domestic waste regularly, pit latrine cleaning, cleaning public toilets, and operating waste collection trucks. Nonetheless, they play an important role in mitigating health-related challenges by ensuring a clean and healthy environment through correct waste collection and disposal practices. Therefore, safe waste collection is a critical undertaking that safeguards the health and living conditions of individuals worldwide. However, their hygiene-related knowledge and practices remain low due to a lack of educational intervention programmes on hygiene. Therefore, the study investigated the impact of an educational intervention on hygiene knowledge and practices amongst municipal waste and sanitation workers in Nelson Mandela Bay Municipality (NMBM). The study used a quasi-experimental study, one group, (pre- and post-test) design, using an educational intervention. A total of 201 municipal waste and sanitation workers were conveniently sampled in the study from all five municipal waste depots and six wastewater treatment plants in the NMBM. A self-administered, structured, hard-copy questionnaire was used to collect the participants’ demographic data and a pre-intervention assessment on hygiene-related knowledge and practices. An educational intervention based on existing literature and national environmental cleaning guidelines and policies was implemented, and after a minimum gap of two months following the intervention, participants were asked to complete the postintervention questionnaire. The collected data was captured in a QuestionPro survey platform and analysed in Microsoft Office 365 (2019 version) and R software (version 4.4.1). The knowledge and practice items were further evaluated for internal reliability using the Cronbach’s alpha technique. Inferential statistics were used to analyse and describe the data, including tests such as Pearson’s correlations, student t-tests, analysis of variance (ANOVA) and multivariable linear regression analysis. A total of 201 participants, comprising 148 (73.6%) males and 53 (26.4%) females, participated in the study. Of the 201 participants, 95 (47.3%) indicated that 2 they had never heard of hygiene-related diseases. The study participants had poor knowledge and practices regarding hygiene prior to the educational intervention. Based on the paired samples t-test, there was a significant difference post-intervention phase in the mean scores for hygiene knowledge of 4.0 (±4.8), p<0.001 as well as hygiene practice scores of 4.3 (±3.4), p<0.001. Output obtained from the multivariable linear regression analysis revealed that participants working in Depot (A) (β=-2.82, p=0.005) were less knowledgeable about hygiene compared to those in Depot (B) in the pre-intervention phase. Participants who have not heard of hygiene-related diseases (β=-3.05, p<0.001) were significantly less knowledgeable about hygiene than their counterparts who have previously heard about hygiene-related diseases. Participants older than 51 years of age had poorer knowledge (b=-0.09, p=0.919) regarding hygiene when compared to the participants who were 18-30 years old. Furthermore, only female participants (b=1.44, p=0.022) and the Coloured ethnic group (b=1.44, p=0.050) had good hygiene practices when handling waste, compared to male participants and those of Black African ethnicity. The study's findings highlight the significant positive impact of an implemented educational intervention programme amongst municipal waste and sanitation workers on improving their knowledge of hygiene-related diseases and hygiene practices when discharging their duties. However, predictor factors such as working environment, educational training background, age, and race significantly influenced the impact of the implemented educational programme. The ongoing implementation of similar initiatives is highly recommended amongst municipal waste and sanitation workers, thus preventing hygiene-related infections amongst the studied population and fostering a healthier environment. , Thesis (MSc) -- Faculty of Science, School of Behavioural & Lifestyle Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Investigating the implementation of teaching strategies used by foundation phase teachers in multilingual classrooms
- Authors: Green, Marizanne
- Date: 2024-12
- Subjects: Multiculturalism -- Study and teaching , Language and languages -- Study and teaching , Education, Bilingual -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68322 , vital:76974
- Description: In South Africa, there are eleven official languages: English and Afrikaans and nine indigenous languages. However, the dominant language of learning and teaching in multilingual classrooms is English. Teachers are not all equipped to cater for a multilingual classroom that is conducive to learning. Hence, it is important that teaching strategies teachers used need to support learners’ access to knowledge and their language proficiency through the learning process. This qualitative case study aimed at investigating the teaching strategies used by Foundation Phase teachers in multilingual classrooms. The study was guided by an interpretivist paradigm which was helpful in providing in-depth knowledge on multilingual Foundation Phase classrooms and the teaching strategies that teachers implement. The study used a purposive sampling strategy with 4 Foundation phase teachers teaching Grades R-4. Drawing upon classroom observations and semi-structured individual interviews as the primary methods of data collection, the study explored the teaching strategies teachers use in multilingual foundation phase classrooms. A thematic data analysis was employed. Findings revealed a need for inclusive practices in FP multilingual classrooms, need to support learning using various teaching strategies, need to recognize realities in multilingual classrooms and a role that stakeholders can play in learning. Recommendations are provided for SGB’s, Curriculum designers, FP teachers and parents. , Thesis (MEd) -- Faculty of Education, School of Primary School Education, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Green, Marizanne
- Date: 2024-12
- Subjects: Multiculturalism -- Study and teaching , Language and languages -- Study and teaching , Education, Bilingual -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68322 , vital:76974
- Description: In South Africa, there are eleven official languages: English and Afrikaans and nine indigenous languages. However, the dominant language of learning and teaching in multilingual classrooms is English. Teachers are not all equipped to cater for a multilingual classroom that is conducive to learning. Hence, it is important that teaching strategies teachers used need to support learners’ access to knowledge and their language proficiency through the learning process. This qualitative case study aimed at investigating the teaching strategies used by Foundation Phase teachers in multilingual classrooms. The study was guided by an interpretivist paradigm which was helpful in providing in-depth knowledge on multilingual Foundation Phase classrooms and the teaching strategies that teachers implement. The study used a purposive sampling strategy with 4 Foundation phase teachers teaching Grades R-4. Drawing upon classroom observations and semi-structured individual interviews as the primary methods of data collection, the study explored the teaching strategies teachers use in multilingual foundation phase classrooms. A thematic data analysis was employed. Findings revealed a need for inclusive practices in FP multilingual classrooms, need to support learning using various teaching strategies, need to recognize realities in multilingual classrooms and a role that stakeholders can play in learning. Recommendations are provided for SGB’s, Curriculum designers, FP teachers and parents. , Thesis (MEd) -- Faculty of Education, School of Primary School Education, 2024
- Full Text:
- Date Issued: 2024-12
Investigating the purported medicinal properties of cannabinoid containing products available for human consumption in South Africa
- Authors: Stark, Nicole Jade
- Date: 2024-12
- Subjects: Thin layer chromatography , Tetrahydrocannabinol , Cannabinoids
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69716 , vital:78013
- Description: Cannabis has until recently, in some countries, been classified as an illicit, illegal drug. In South Africa, the sale of marijuana (Cannabis sativa) is still illegal, but there has been an amendment of legislation in the governing of the use of marijuana in that the private use of marijuana was decriminalised in September 2018. This has led to questions about whether the recreational use of Cannabis should be legalised and what is the potential social implications of this legislation moving forward (Mokwena, 2019). This study aimed to assess whether the indications and consequently the concentrations associated with the declared purported use of cannabinoid containing products correspond with the information declared on the label and conform to the regulatory limits set out for these products. The objectives of this study were to explore: the range of products available in South Africa, the prescribed use and dosage of the product and to test the accuracy of the reported information on the product labelling regarding the cannabinoid content. This investigation pursued a quantitative approach that is empirical and comprised of laboratory-based experiments. A minimum of seven samples of different liquid preparations of products, reported to contain cannabinoids and being sold without the need for a prescription or licence were tested with the aid of Thin Layer Chromatography (TLC), to separate individual compounds from the many that could be found in these Cannabis products. The results of this testing of cannabidiol (CBD) and tetrahydrocannabinol (THC) and, where applicable, their concentrations were determined. Using the data collected and review of available literature, assessments were made as to whether the products tested conform to the regulatory standards and contained the cannabinoids as stated on the labelling. From the data obtained findings were that not all products currently available on the South African market correspond to the information reported on the label or conform to the regulatory standards. , Thesis (MPharm) -- Faculty of Health Sciences, School of Clinical Care & Medicinal Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Stark, Nicole Jade
- Date: 2024-12
- Subjects: Thin layer chromatography , Tetrahydrocannabinol , Cannabinoids
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/69716 , vital:78013
- Description: Cannabis has until recently, in some countries, been classified as an illicit, illegal drug. In South Africa, the sale of marijuana (Cannabis sativa) is still illegal, but there has been an amendment of legislation in the governing of the use of marijuana in that the private use of marijuana was decriminalised in September 2018. This has led to questions about whether the recreational use of Cannabis should be legalised and what is the potential social implications of this legislation moving forward (Mokwena, 2019). This study aimed to assess whether the indications and consequently the concentrations associated with the declared purported use of cannabinoid containing products correspond with the information declared on the label and conform to the regulatory limits set out for these products. The objectives of this study were to explore: the range of products available in South Africa, the prescribed use and dosage of the product and to test the accuracy of the reported information on the product labelling regarding the cannabinoid content. This investigation pursued a quantitative approach that is empirical and comprised of laboratory-based experiments. A minimum of seven samples of different liquid preparations of products, reported to contain cannabinoids and being sold without the need for a prescription or licence were tested with the aid of Thin Layer Chromatography (TLC), to separate individual compounds from the many that could be found in these Cannabis products. The results of this testing of cannabidiol (CBD) and tetrahydrocannabinol (THC) and, where applicable, their concentrations were determined. Using the data collected and review of available literature, assessments were made as to whether the products tested conform to the regulatory standards and contained the cannabinoids as stated on the labelling. From the data obtained findings were that not all products currently available on the South African market correspond to the information reported on the label or conform to the regulatory standards. , Thesis (MPharm) -- Faculty of Health Sciences, School of Clinical Care & Medicinal Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Investigation of potential in-situ polymerization reactions for use in lithium-ion batteries
- Authors: Dube, Tafara
- Date: 2024-12
- Subjects: Lithium ion batteries , Lithium cells , Electrochemistry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68851 , vital:77127
- Description: With the rise in popularity of electric vehicles and portable electronic devices, having a reliable, lightweight, and long-lasting battery is crucial. This has led to the mass commercialisation of lithium-ion batteries (LIB’s) because they offer several advantages over other battery technologies. Over the years, one of the concerns was with the ease with which the batteries can burn or explode when subjected to certain extreme conditions. In order to build trust in these products and to expand the technology into more diverse applications, safety aspects of the batteries has become of widespread concern resulting in a key area of research. One aspect of improving the safety is by reducing the flammability of the battery by the addition of certain chemicals that stop or suppress the thermal runaway effect. However, this in-turn reduces the battery’s capacity and life-cycle performance. Researchers have used the idea of encapsulating these chemicals thereby physically separating them within the lithium-ion battery (LIB) electrolyte system with a minimum effect on performance. This research aims to explore use of R-diols and R-amines as additives that upon a thermal trigger would react with the lithium-ion battery electrolyte to stop the effect of the thermal runaway by forming carbamate derivatives which are gel-like or form solid aggregates. The R-diols or R-amines can react with electrolyte at higher temperatures with the lithium-hexafluorophosphate acting as a catalyst. This change in the physical state of the electrolyte increases the resistance inside the battery which then hinders ion movement and forms a physical barrier to reduce the effect of short circuiting when the separator or other components are damaged due to higher temperatures. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Dube, Tafara
- Date: 2024-12
- Subjects: Lithium ion batteries , Lithium cells , Electrochemistry
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68851 , vital:77127
- Description: With the rise in popularity of electric vehicles and portable electronic devices, having a reliable, lightweight, and long-lasting battery is crucial. This has led to the mass commercialisation of lithium-ion batteries (LIB’s) because they offer several advantages over other battery technologies. Over the years, one of the concerns was with the ease with which the batteries can burn or explode when subjected to certain extreme conditions. In order to build trust in these products and to expand the technology into more diverse applications, safety aspects of the batteries has become of widespread concern resulting in a key area of research. One aspect of improving the safety is by reducing the flammability of the battery by the addition of certain chemicals that stop or suppress the thermal runaway effect. However, this in-turn reduces the battery’s capacity and life-cycle performance. Researchers have used the idea of encapsulating these chemicals thereby physically separating them within the lithium-ion battery (LIB) electrolyte system with a minimum effect on performance. This research aims to explore use of R-diols and R-amines as additives that upon a thermal trigger would react with the lithium-ion battery electrolyte to stop the effect of the thermal runaway by forming carbamate derivatives which are gel-like or form solid aggregates. The R-diols or R-amines can react with electrolyte at higher temperatures with the lithium-hexafluorophosphate acting as a catalyst. This change in the physical state of the electrolyte increases the resistance inside the battery which then hinders ion movement and forms a physical barrier to reduce the effect of short circuiting when the separator or other components are damaged due to higher temperatures. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2024
- Full Text:
- Date Issued: 2024-12
Low-income area electrification systems
- Authors: Tshabeni, Thulisa
- Date: 2024-12
- Subjects: Rural electrification -- Economic aspects -- South Africa , Rural electrification -- South Africa , Remote area power supply systems -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68807 , vital:77115
- Description: This research investigated electrification systems for low-income, informal settlement areas via grid extension, photovoltaic mini-grids and solar home system (SHS). Six electrification systems were analysed; four mini-grid systems, a 100 W solar home system and a grid extension. All have different maximum power capacities and differ in the way they contribute to sustainable development. Affordability for the consumer of the total energy required (electrical and other sources) is a key factor for the sustainability of any electrification system. Two battery technologies, lithium-ion and lead acid batteries were compared for each system based on technical and economic performance. The study determined that despite the intial very high cost, lithium-ion batteries can achieve a lower levelized cost of electricity (LCOE) due to their long life span. It was found that the batteries cost between 58% and 95% of the project’s capital cost. The battery cost occurs not only in the capital cost, but in the replacement cost. This cost is so high, that it makes all the solar systems uneconomic. This research found that extending the national power grid is still much more economically viable than all other PV electrification systems, but it requires land tenure. The issue of land tenure could be solved by making some agreement with the land owner for rental. It was found that the PV systems could only be economic if they increased the income of the communities substantially. , Thesis (MEg) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Tshabeni, Thulisa
- Date: 2024-12
- Subjects: Rural electrification -- Economic aspects -- South Africa , Rural electrification -- South Africa , Remote area power supply systems -- South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68807 , vital:77115
- Description: This research investigated electrification systems for low-income, informal settlement areas via grid extension, photovoltaic mini-grids and solar home system (SHS). Six electrification systems were analysed; four mini-grid systems, a 100 W solar home system and a grid extension. All have different maximum power capacities and differ in the way they contribute to sustainable development. Affordability for the consumer of the total energy required (electrical and other sources) is a key factor for the sustainability of any electrification system. Two battery technologies, lithium-ion and lead acid batteries were compared for each system based on technical and economic performance. The study determined that despite the intial very high cost, lithium-ion batteries can achieve a lower levelized cost of electricity (LCOE) due to their long life span. It was found that the batteries cost between 58% and 95% of the project’s capital cost. The battery cost occurs not only in the capital cost, but in the replacement cost. This cost is so high, that it makes all the solar systems uneconomic. This research found that extending the national power grid is still much more economically viable than all other PV electrification systems, but it requires land tenure. The issue of land tenure could be solved by making some agreement with the land owner for rental. It was found that the PV systems could only be economic if they increased the income of the communities substantially. , Thesis (MEg) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 2024
- Full Text:
- Date Issued: 2024-12
Portfolio effect and bet-hedging adaptations in sea turtles
- Authors: Hoekstra, Shaun
- Date: 2024-12
- Subjects: Wildlife conservation , Sea turtles -- South Africa , Animal behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68873 , vital:77153
- Description: A great proportion of marine species are at risk of going extinct as a result of profound changes in the world’s oceans, primarily driven by human activities. Sea turtles are not exempt from this fate. Despite sea turtles being exposed to a range of environmental conditions and threats that vary in frequency and intensity, these ancient marine reptiles have persisted for millennia. In the past, sea turtles have been able to adapt to natural perturbations while other animal groups have not. The ability of sea turtles to adapt to contemporary changes in conditions, produced by human activities, has become limited. The persistence of sea turtles may be explained by the application of a concept termed “portfolio effect”. An aggregate system is more stable and less prone to fluctuations over time (i.e. portfolio effect) if a diversity of finer components comprises the entire system and displays asynchronous fluctuations over time. Biological entities (e.g. species measured by the abundance trend) may achieve long-term stability even though the individual components (e.g. populations measured in abundance trend) display weak or negative correlations with each other in space and time. Different sea turtle populations may display independent trends in abundances over time, resulting in a portfolio effect at species levels. Trends in sea turtle abundances may be affected by individual behaviour. The adoption of bet-hedging adaptations may enable populations to thrive despite environmental changes or stochasticity, by lowering short-term fitness in exchange for maximising long-term fitness. Individual sea turtles may exhibit bet-hedging adaptations through changes in their temporal nesting behaviour, including the remigration interval. Since remigration interval length regulates the number of nesting females per nesting season, changes in remigration interval will affect abundance trends. The ability of individuals to change their remigration interval allows them to “skip” the breeding migration when environmental conditions seem unfavourable. The overall aim of this thesis was to investigate potential reasons for observed sea turtle abundance trends at species, population, and rookery levels. I tested whether the portfolio effect applies to sea turtles by analysing and interpreting spatiotemporal trends in loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) abundances at the population and species levels using global datasets. The application of bet-hedging strategies was tested at a local level using data from the long-term monitoring program for South African nesting sea turtles. The majority of loggerhead rookeries displayed an increase in abundance over time, while most leatherback rookeries declined (Chapter 2). Population growth rates also differed among rookeries within Regional Management Units (RMUs) (Chapter 2). This diversity in abundance trends among rookeries suggested spatiotemporal variation in environmental conditions, threats and/or level of protection accompanying sea turtles. The species-level growth rate for both species displayed an overall increase in abundance over time. However, larger (more turtles) leatherback rookeries/RMUs experienced more rapid declines in abundance compared to smaller rookeries/RMUs, resulting in a recent species-level decline. Uncorrelated trends in abundances at the RMU-level could have stabilised species-level trends. Differences in the remigration intervals as a possible bet-hedging adaptation could potentially explain differences in population recovery rates between South Africa’s loggerhead and leatherback sea turtles (Chapter 3), but found no evidence that individuals from either species exhibit bet-hedging adaptations. Loggerheads, however, have increased their remigration intervals over time, while leatherbacks have not. These increases were accompanied by declines in adult body size (previously established) which could be an effect of diminishing foraging area quality. The increased remigration interval shown by loggerheads may be a response rather than an adaptation to the prevailing environmental conditions that impact their food supply in their foraging areas. The population growth rate of leatherback sea turtles may surpass that of the loggerheads in the near future, although there is a global decline in abundance (Chapter 2). This dissertation provides information on possible reasons for observed trends in sea turtle abundances at various levels of biological organisation. While a variety of factors have the potential to influence trends in sea turtle abundance, the possible occurrence of portfolio effects and investigating nesting behaviour may resolve any uncertainties regarding the reasons for observed trends in abundance. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-12
- Authors: Hoekstra, Shaun
- Date: 2024-12
- Subjects: Wildlife conservation , Sea turtles -- South Africa , Animal behavior
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/68873 , vital:77153
- Description: A great proportion of marine species are at risk of going extinct as a result of profound changes in the world’s oceans, primarily driven by human activities. Sea turtles are not exempt from this fate. Despite sea turtles being exposed to a range of environmental conditions and threats that vary in frequency and intensity, these ancient marine reptiles have persisted for millennia. In the past, sea turtles have been able to adapt to natural perturbations while other animal groups have not. The ability of sea turtles to adapt to contemporary changes in conditions, produced by human activities, has become limited. The persistence of sea turtles may be explained by the application of a concept termed “portfolio effect”. An aggregate system is more stable and less prone to fluctuations over time (i.e. portfolio effect) if a diversity of finer components comprises the entire system and displays asynchronous fluctuations over time. Biological entities (e.g. species measured by the abundance trend) may achieve long-term stability even though the individual components (e.g. populations measured in abundance trend) display weak or negative correlations with each other in space and time. Different sea turtle populations may display independent trends in abundances over time, resulting in a portfolio effect at species levels. Trends in sea turtle abundances may be affected by individual behaviour. The adoption of bet-hedging adaptations may enable populations to thrive despite environmental changes or stochasticity, by lowering short-term fitness in exchange for maximising long-term fitness. Individual sea turtles may exhibit bet-hedging adaptations through changes in their temporal nesting behaviour, including the remigration interval. Since remigration interval length regulates the number of nesting females per nesting season, changes in remigration interval will affect abundance trends. The ability of individuals to change their remigration interval allows them to “skip” the breeding migration when environmental conditions seem unfavourable. The overall aim of this thesis was to investigate potential reasons for observed sea turtle abundance trends at species, population, and rookery levels. I tested whether the portfolio effect applies to sea turtles by analysing and interpreting spatiotemporal trends in loggerhead (Caretta caretta) and leatherback (Dermochelys coriacea) abundances at the population and species levels using global datasets. The application of bet-hedging strategies was tested at a local level using data from the long-term monitoring program for South African nesting sea turtles. The majority of loggerhead rookeries displayed an increase in abundance over time, while most leatherback rookeries declined (Chapter 2). Population growth rates also differed among rookeries within Regional Management Units (RMUs) (Chapter 2). This diversity in abundance trends among rookeries suggested spatiotemporal variation in environmental conditions, threats and/or level of protection accompanying sea turtles. The species-level growth rate for both species displayed an overall increase in abundance over time. However, larger (more turtles) leatherback rookeries/RMUs experienced more rapid declines in abundance compared to smaller rookeries/RMUs, resulting in a recent species-level decline. Uncorrelated trends in abundances at the RMU-level could have stabilised species-level trends. Differences in the remigration intervals as a possible bet-hedging adaptation could potentially explain differences in population recovery rates between South Africa’s loggerhead and leatherback sea turtles (Chapter 3), but found no evidence that individuals from either species exhibit bet-hedging adaptations. Loggerheads, however, have increased their remigration intervals over time, while leatherbacks have not. These increases were accompanied by declines in adult body size (previously established) which could be an effect of diminishing foraging area quality. The increased remigration interval shown by loggerheads may be a response rather than an adaptation to the prevailing environmental conditions that impact their food supply in their foraging areas. The population growth rate of leatherback sea turtles may surpass that of the loggerheads in the near future, although there is a global decline in abundance (Chapter 2). This dissertation provides information on possible reasons for observed trends in sea turtle abundances at various levels of biological organisation. While a variety of factors have the potential to influence trends in sea turtle abundance, the possible occurrence of portfolio effects and investigating nesting behaviour may resolve any uncertainties regarding the reasons for observed trends in abundance. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Full Text:
- Date Issued: 2024-12